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To produce the fermented beet juice, the association of the cultures Lactobacillus fermentum 27 and Lactobacillus plantarum 22 was recommended. The conditions for preparing a dried starter from the association of lactic acid bacteria L. fermentum 27 and L. plantarum 22 have been selected. It was established that the optimal protective components for freeze drying of the bacteria include 7% glucose together with 5% dried skimmed milk and a combination of 5% sucrose, 5% lactose, and 5% dried skimmed milk. The possibility of using beet residues to enhance the antimicrobial activity of lactic acid bacteria has been demonstrated.

Lactic acid bacteria were evaluated for their ability to reduce nitrite and produce acid. Tests were conducted in broth, model meat systems, and a fermented sausage. The bacteria were screened for their ability to reduce nitrite irrespective of pH effects, in broth containing no added carbohydrate. Lactobacillus leichmannii, Streptococcus faecalis, and several atypical lactobacilli isolated from fresh beef and mutton reduced 200-1000 ppm nitrite in 48-72 hours. Reduction by L. leichmannii and S. faecalis was inhibited by carbon monoxide, suggesting a possible heme-containing nitrite reductase enzyme. Studies conducted in broth and model meat systems showed significant differences in nitrite reduction and acid production with longer incubation times, higher temperatures, and increased carbohydrate levels. Differences were observed in degree of nitrite reduction due to meat source (beef versus mutton) and bacterial treatment. Residual nitrite and pH were highly correlated in all media containing fermentable carbohydrate.

Edible fruits and vegetables are easily degraded or denatured by several reasons especially from environmental factors. Due that the shelf life of plant materials are drastically reduced. It may affect the economic value of individual persons. From this research work was undertaken few selected curd samples, tomato samples and grapes from various areas for selecting significant lactic acid bacteria (LAB). Screening of probiotics was done by the detection of antagonistic activities, acid and bile salt tolerance test, antibiotic resistance test and sensitivity pattern and antimicrobial activity study. In the present studies, total 52 fruit flora bacterial cultures were isolated from two different site oriented tomato and grapes.LAB colonies in 10-5 dilution were expressed good loading capacity in curd sample, grapes and tomato. In antagonistic activity, Lactobacillus delburecki and Lactobacillus sp. were observed highest zone against Shigella sp. From this, Lacto bacillus delburecki and Lactobacillus sp. were actively preserved the selected vegetables. They were increased the shelf-life and reduced the degradation of the samples

This study covers proximate analysis and Antimicrobial activities of cell free extract of lactic acid bacterial from Blighia sapida fruit (Ackee). The proximate analysis of Blighia sapida were determined using standard methods which varied in contents. The proximate analysis of the sample were ash content (6.10±0.03%), moisture content (5.43±0.12%), fat content (14.60±0.02%), crude fibre content (25.12±0.02%), protein content (14.19±0.09%) and carbohydrate content (34.19±0.23%). Probiotic of lactic acid bacteria isolated from Blighia sapida (Ackee) were identified as Lactobacillus leshmanni, and Lactobacillus acidophilus, with Streptomycin sulphate as control. Antimicrobial activities of the lactic acid isolated were determined by the agar well diffusion methods against pathogenic bacteria: Escherichia coli, Staphylococcus aureus, Xanthomonas sp, Pseudomonas aeruginosa, Salmonella typhi and Bacillus subtilis. The zone of inhibition ranged from 3mm to 25mm and control ranged from 23mm to 30mm. Lactobacillus acidophilus displayed high antimicrobial activity compared with Lactobacillus leshmanni showing its probiotic potential of lactic acid bacteria use for food supplement.

This article is from Bioscience of Microbiota, Food and Health , volume 32 . Abstract Lactic acid bacteria (LAB) are often used for prevention and treatment of dysbiosis. However, the action of various strains of LAB on metabolism and digestion under these conditions are poorly understood. The purpose of this study was to investigate the influence of probiotic LAB on metabolism, digestion and microbiota in animals with dysbiosis. After administration of ampicillin and metronidazole male Wistar rats, were fed products containing Enterococcus faecium L3 (E.f.), Lactobacillus fermentum Z (L.f.) or milk (control 1). Animals in control group 2 were fed milk, after water instead of antibiotics. Dyspeptic symptoms disappeared after administration of probiotic compared with control 1. At the end of the experiment, an increase in the content of enterococci and lactobacilli in the proximal part of the small intestine was found in the animals treated with E.f. and L.f., respectively. After the introduction of probiotic enterococci, the quantity of lactobacilli and bifidobacteria in the intestines of rats increased, and the content of Klebsiella spp. and Escherichia coli decreased in comparison with the control group 1 and the group fed lactobacilli. The activity of alkaline phosphatase and aspartate transaminase was greater in blood serum of rats with dysbiosis receiving milk and lactobacilli. Intestinal alkaline phosphatase activity increased in the epithelium and chyme in the jejunum of the animals treated with L. f. and in the chyme only in the animals treated with E. f. Thus, the specific effects of different strains of probiotic LAB on the microbiota, and on metabolism and digestion of various nutrients were demonstrated.

This article is from PeerJ , volume 2 . Abstract Cassava beer, or chicha, is typically consumed daily by the indigenous Shuar people of the Ecuadorian Amazon. This traditional beverage made from cassava tuber (Manihot esculenta) is thought to improve nutritional quality and flavor while extending shelf life in a tropical climate. Bacteria responsible for chicha fermentation could be a source of microbes for the human microbiome, but little is known regarding the microbiology of chicha. We investigated bacterial community composition of chicha batches using Illumina high-throughput sequencing. Fermented chicha samples were collected from seven Shuar households in two neighboring villages in the Morona-Santiago region of Ecuador, and the composition of the bacterial communities within each chicha sample was determined by sequencing a region of the 16S ribosomal gene. Members of the genus Lactobacillus dominated all samples. Significantly greater phylogenetic similarity was observed among chicha samples taken within a village than those from different villages. Community composition varied among chicha samples, even those separated by short geographic distances, suggesting that ecological and/or evolutionary processes, including human-mediated factors, may be responsible for creating locally distinct ferments. Our results add to evidence from other fermentation systems suggesting that traditional fermentation may be a form of domestication, providing endemic beneficial inocula for consumers, but additional research is needed to identify the mechanisms and extent of microbial dispersal.

This article is from Microbial Cell Factories , volume 13 . Abstract Bacteriocins are heat-stable ribosomally synthesized antimicrobial peptides produced by various bacteria, including food-grade lactic acid bacteria (LAB). These antimicrobial peptides have huge potential as both food preservatives, and as next-generation antibiotics targeting the multiple-drug resistant pathogens. The increasing number of reports of new bacteriocins with unique properties indicates that there is still a lot to learn about this family of peptide antibiotics. In this review, we highlight our system of fast tracking the discovery of novel bacteriocins, belonging to different classes, and isolated from various sources. This system employs molecular mass analysis of supernatant from the candidate strain, coupled with a statistical analysis of their antimicrobial spectra that can even discriminate novel variants of known bacteriocins. This review also discusses current updates regarding the structural characterization, mode of antimicrobial action, and biosynthetic mechanisms of various novel bacteriocins. Future perspectives and potential applications of these novel bacteriocins are also discussed.

This research aims to looking for 2 candidates from the new probioticlactic acid bacteria fermented food origin. This study uses seven isolates were isolated from whey, cassava, and fish budu. 7 isolates have been tested potential as a producer of glutamic acid but not known as a candidate probiotic petensinya. This study uses a completely randomized design, each repeated 3 times with 5 stages of the research are: 1) Testing capability isolates at low pH (pH 2.5); 2) testing the ability of isolates in bile (0.3 and 0.5%); 3) Viability isolates 4) Testing capability isolates in killing the pathogenic bacteria (Escherichia coli, Staphylococcus aureus and Salmonella enteritidis). The results showed the 7 isolates can be used as a probiotic candidates with the results of the resistance to pH 2.5 for 3 hours is 63.91-92.75% and the 6 hour incubation is 48,76-72.44%, resistance to bile salt concentration of 0.3% showed resistance to 22.86-83.57% and a concentration of 0.5% showed resistance 18.35-72,77%, 81.05-92.67% viability and inhibitory effect on the bacteria Escherichia coli is 7:33 to 12:01 mm, is 11:11 to 14:05 mm Staphylococcus aureus and Salmonella enteritidis is 12:02 to 18:08 mm. From 7 isolates after penseleksian ability as a candidate probiotic mixture then isolate F6 from durian fermented and isolate C8 from buffalo milk fermented (Dadih) are able to live at pH 2.5 for 3 hours of 92.75% and 86.06%, at 6 hours of 72.44 and 71.42%, the bile salt 0.3% were 83.57% and 78.75% and the concentration 0.5% are 77.17% and 72.77%, with viability were 92.67% and 92.23%, while the ability to kill pathogens such as Escherichia coli was 10.49 and 8.89 mm, Staphylococcus aureus was 14.05 and 13.70 mm, dan Salmonella enteritidis was 18.08 and 14.18 mm.

In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. (For more information: 12 Tables of Code ) Name of Standards Organization: Bureau of Indian Standards (BIS) Division Name: Food and Agriculture Section Name: Food Hygiene, Safety Management and Other Systems (FAD 15) Designator of Legally Binding Document: IS 16068 Title of Legally Binding Document: Microbiology of Food and Animal Feed Stuffs - Horizontal Method for the Enumeration of Mesophilic Lactic Acid Bacteria - Colony-Count Technique Number of Amendments: Equivalence: ISO 15214:1998 Superceding: Superceded by: LEGALLY BINDING DOCUMENT Step Out From the Old to the New --Jawaharlal Nehru Invent a new India using knowledge. --Satyanarayan Gangaram Pitroda

In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. (For more information: 12 Tables of Code ) Name of Standards Organization: Bureau of Indian Standards (BIS) Division Name: Food and Agriculture Section Name: Dairy Products and Equipment (FAD 19) Designator of Legally Binding Document: IS 12899 Title of Legally Binding Document: Dairy Products - Yoghurt, Enumeration of Specific Lactic Acid Bacteria - Method of Test Number of Amendments: Equivalence: Superceding: Superceded by: LEGALLY BINDING DOCUMENT Step Out From the Old to the New --Jawaharlal Nehru Invent a new India using knowledge. --Satyanarayan Gangaram Pitroda

This article is from Bioscience of Microbiota, Food and Health , volume 31 . Abstract L-leucyl-L-leucine methyl ester (LLME) is known to remove lysosome-rich cells from human peripheral blood mononuclear cells (PBMCs). To evaluate the immunopotentiating ability of lactic acid bacteria (LAB), we adopted the in vitro stimulation protocol of LLME-treated PBMCs as a model assay system and monitored the level of antibody produced by stimulated PBMCs. The results indicated that several LAB strains have immunopotentiating ability against PBMCs, as evidenced by the enhanced antibody production and increased number of antigen-specific B cells. Next, we identified T cells as the direct target cells of the immunopotentiating LAB strain L32, suggesting that L32 induced antibody production by PBMCs through T-cell activation. Finally, we tested the immunopotentiating ability of ligands for Toll-like receptor 2 (TLR2), which is known to mediate the LAB signal, and observed that both L32 and one of the TLR2 ligands, LTA-BS, induced antigen-specific antibody production by in vitro stimulated PBMC. This suggests that L32 and LTA-BS can be used as an adjuvant for stimulating immune reaction in PBMCs.

This article is from Bioscience of Microbiota, Food and Health , volume 32 . Abstract Visceral fat accumulation is a major risk factor for the development of obesity-related diseases, including diabetes, hyperlipidemia, hypertension, and arteriosclerosis. Stimulation of lipolytic activity in adipose tissue or inhibition of fat synthesis is one way to prevent these serious diseases. Lactic acid bacteria have an anti-obesity effect, but the mechanisms are unclear. Therefore, we evaluated the effect of the administration of lactic acid bacteria (Lactobacillus gasseri NT) on lipid metabolism and fat synthesis in a mouse high-fat-diet model, focusing on visceral fat. Balb/c mice were fed a 45 kcal% fat diet for 13 weeks with and without a freeze-dried preparation of L. gasseri NT (109 CFU/g). An ex vivo glycerol assay with periovarian fat revealed that L. gasseri NT did not stimulate lipolytic activity. However, L. gasseri NT decreased the mRNA expression of sterol regulatory element-binding protein (SREBP) and its target gene fatty acid synthase (FAS) in the liver and decreased free fatty acid (FFA) in the blood. In conclusion, these findings indicated that administration of L. gasseri NT did not enhance lipid mobilization but can reduce fat synthesis, suggesting its potential for improving obesity-related diseases.

This article is from Bioscience of Microbiota, Food and Health , volume 32 . Abstract Thrombosis is characterized by congenital and acquired procatarxis. Lactic acid bacteria-fermented soybean milk products (FS-LAB) inhibit hepatic lipid accumulation and prevent atherosclerotic plaque formation. However, the therapeutic efficacy of FS-LAB against thrombosis has yet to be investigated. In this study, FS-LAB were administered subcutaneously into the tails of rats, with the subsequent intravenous administration of κ-carrageenan 12 hr after the initial injection. In general, administration of κ-carrageenan induces thrombosis. The length of the infarcted tail regions was significantly shorter in the rats administered a single-fold or double-fold concentration of the FS-LAB solution compared with the region in control rats. Therefore, FS-LAB exhibited significant antithrombotic effects. Our study is the first to characterize the properties of FS-LAB and, by testing their efficacy on an in vivo rat model of thrombosis, demonstrate the potency of their antithrombotic effect.

This article is from Microbial Cell Factories , volume 13 . Abstract Genome analysis using next generation sequencing technologies has revolutionized the characterization of lactic acid bacteria and complete genomes of all major groups are now available. Comparative genomics has provided new insights into the natural and laboratory evolution of lactic acid bacteria and their environmental interactions. Moreover, functional genomics approaches have been used to understand the response of lactic acid bacteria to their environment. The results have been instrumental in understanding the adaptation of lactic acid bacteria in artisanal and industrial food fermentations as well as their interactions with the human host. Collectively, this has led to a detailed analysis of genes involved in colonization, persistence, interaction and signaling towards to the human host and its health. Finally, massive parallel genome re-sequencing has provided new opportunities in applied genomics, specifically in the characterization of novel non-GMO strains that have potential to be used in the food industry. Here, we provide an overview of the state of the art of these functional genomics approaches and their impact in understanding, applying and designing lactic acid bacteria for food and health.

This article is from Veterinary Research , volume 42 . Abstract This study analyzed the functional expression of TLR3 in various gastrointestinal tissues from adult swine and shows that TLR3 is expressed preferentially in intestinal epithelial cells (IEC), CD172a+CD11R1high and CD4+ cells from ileal Peyer's patches. We characterized the inflammatory immune response triggered by TLR3 activation in a clonal porcine intestinal epitheliocyte cell line (PIE cells) and in PIE-immune cell co-cultures, and demonstrated that these systems are valuable tools to study in vitro the immune response triggered by TLR3 on IEC and the interaction between IEC and immune cells. In addition, we selected an immunobiotic lactic acid bacteria strain, Lactobacillus casei MEP221106, able to beneficially regulate the anti-viral immune response triggered by poly(I:C) stimulation in PIE cells. Moreover, we deepened our understanding of the possible mechanisms of immunobiotic action by demonstrating that L. casei MEP221106 modulates the interaction between IEC and immune cells during the generation of a TLR3-mediated immune response.

This article is from Microbial Cell Factories , volume 11 . Abstract Lactic acid bacteria (LAB) have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms.

The objective of “this study was to determine the genetic variability of lactic acid bacteria (LAB) present in locally sourced cow's milk. A total of 50 raw milk samples were collected from several local markets in Al-Kut. The specimens were cultured in the De man, Rogosa, and Sharpe (MRS) medium, which is particularly formulated to promote the growth of lactic acid bacteria. The presumed isolates were then identified by the use of polymerase chain reaction (PCR), which selectively targets the 16S rRNA gene, and afterwards followed by DNA sequencing”. The results revealed that lactic acid bacteria were present in 28% (14 isolates) of the samples, including two genera and five species. Specifically, there were 2 strains of Lactococcus lactis and 12 strains of Lactobacillus spp, including 5 Lactobacillus Plantarum, 4 Lactobacillus gasseri, 2 Lactobacillus acidophilus, and 1 Lactobacillus delbrueckii. The predominant Lactic acid Bactria in the present study (Lactobacillus Plantarum) were furtherly tested for their antibacterial activity and the results showed that , Lactobacillus Plantarum exhibited potent antibacterial effects against indicator bacteria like “Staphylococcus aureus and Staphylococcus epidermidis, as well as pathogenic bacteria such as E.coli and Pseudomonas” aeruginosa. The 16S rRNA gene sequencing and phylogenetic tree analysis indicated that all the obtained strains exhibited 99% homology with certain LAB strains published in the NCBI. Subsequently, the isolates were recorded in the NCBI.

Lactic Acid Bacteria Serum

 Langsat fruit (Lansiumdomesticum) sample collected from 4 district in Minahasa, North Celebes. Lactic Acid Bacteria (LAB) isolates were found at that samples. The study aim to examinedthe antibacterial activity of Lactic acid bacteria (LAB) from Langsat fruit sample against pathogenic bacteria Escherichia coli (Gram Negatrive Bacteria) and spoilage bacteria Staphylococcus aureus (Gram Positive Bacteria) using agar well diffusion method.The isolation result obtained 42 isolates of LAB namely 10 isolate were obtained from Southeast Minahasa district, 8 isolates were obtained from the southern district of Minahasa, 12 isolates were obtained from from the Minahasa district, and 12 isolates were obtained from North Minahasa district. Fourty two isolates LAB identified as Lactobacillus genera based on profile matching method were effective against bacteria indicator (pathogenic and spoilage bacteria). The antibacterial activity showed through the formation of a clear zone around well that containing LAB isolates. The diameter inhibition of LAB isolates ranged from 3,0 – 17,0 mm. Overall, the isolated LAB showed the remarkable inhibitory effect against both Gram positive (spoilage bacteria) and Gram negative (pathogenic bacteria). However, the spectrum of inhibition was different for the isolates tested. These results suggest that this potent isolates could be used as a natural biopreservativesagent.

"A Preliminary Note on a Group of Lactic Acid Bacteria not Previously Described in America" is an article from Science, Volume 28 . View more articles from Science . View this article on JSTOR . View this article's JSTOR metadata . You may also retrieve all of this items metadata in JSON at the following URL: https://archive.org/metadata/jstor-1635829

"A Preliminary Note on a Group of Lactic Acid Bacteria not Previously Described in America" is an article from Science, Volume 28 . View more articles from Science . View this article on JSTOR . View this article's JSTOR metadata . You may also retrieve all of this items metadata in JSON at the following URL: https://archive.org/metadata/jstor-1635829

Lactic acid bacteria (LAB), which include genera such as Lactobacillus, Lactococcus, Pediococcus, Enterococcus, and Streptococcus, are commonly found in dairy products and produce a variety of bioactive metabolites. These metabolic by-products have been associated with health-promoting effects, including antioxidant, antiallergic, and immunomodulatory activities, enhanced bioavailability of nutrients, and protection against infectious agents. Due to these properties, LAB have been widely explored across various sectors, especially in biotechnology, the food industry, and therapeutic products. Their applications include acting as barriers against spoilage and pathogenic microorganisms, production of antifungal and antimycotoxigenic agents, nutraceuticals, and, most notably, bacteriocins—antibacterial peptides with significant potential as natural preservatives. Bacteriocins possess desirable features such as thermal stability, activity across a broad pH range, and being colorless, odorless, and tasteless, which enhances their applicability in food systems. This has driven growing research into their effectiveness, particularly against key pathogenic microorganisms such as Listeria monocytogenes and Staphylococcus aureus, which are frequently associated with contamination in dairy products. In this context, this study aims to evaluate the effectiveness of using bacteriocinogenic lactic acid bacteria in preventing Listeria spp. and Staphylococcus spp. contamination in cheese, as well as to describe the methods used for their application in these products.

The aim of this study is to isolate and identify probiotic lactic acid bacteria. About four isolates of lactic acid bacteria were isolated from different sources of milk products. Identification of isolates was done by morphological, biochemical and physiological characterizations. Results indicated that all the four isolates were able to tolerate acidic conditions at low pH (3) and survived at different concentration of bile salts (0.5-1.5%) and showed tolerance to 6.5% NaCl concentration. All isolates have antioxidant activity ranged from 63.2% to 83.7% and cholesterol removal ranged from 17% to 27%. The genetic relationships among the isolates were determined by Inter Simple Sequence Repeat (ISSR) technique Polymerase Chain Reaction (PCR), the results demonstrated a distinctive comparison of clusters and their pattern was greatly related to the clustering obtained with the morphological and biochemical identification. The selected lactic acid bacteria exhibited excellent probiotic characteristics and thus can be used as a potential source of probiotic.

Folate, an essential vitamin and an important factor takes part in human life for the synthesis of nucleotides, vitamins and some amino acids. This vitamin cannot be synthesized in humans’ metabolism and must be taken exogenously to prevent folate deficiency, neural tube defects (NTDs) and other related diseases. The chemically synthesized form of folate is folic acid used for fortification and supplementation of foods, but it can cause some problems such as vitamin B-12 deficiency in high intake. Milk and fermented dairy products represent a good source of natural folate and folate binding proteins, which increase the bioavailability and stability of folate. Many plants, fungi and bacteria synthesize and produce folate. However, folate concentrations in fermented dairy products are higher than in non-fermented dairy products. Some bacteria and yeasts are used as co-culture for natural folate bio-enrichment of fermented milk in the last years. The selection and use of folate-producing microorganisms is an interesting approach to supplement "natural" folate levels in foods. The certain bacteria can contribute to the folate intake directly with foods such as fermented dairy products, or in the intestine as probiotic microorganisms or part of the natural microbiota.

Nowadays, plant-based dairy alternatives have gained considerable attention. However, the textural and sensorial characteristics of plant-based products limit their acceptance. The exploitation of lactic acid bacteria has been proposed as a promising approach to developing plant-based dairy analogs. In this study, the performance of three proteolytic lactic acid bacteria in the induction of soymilk gelation was compared and their effects on the physicochemical properties of resulting gels were investigated. Lactiplantibacillus plantarum MCM4, Streptococcus thermophilus , and Weissella confusa MDM8 ) were inoculated to the soy milk matrix, and incubated at 37 °C until reaching pH 4.7. To understand the effects of acidifying and proteolytic activity of starter culture, syneresis, cell counts, free amino acid content (O-phthalaldehyde method), evaluation of proteolysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and textural parameters of soymilk gels during fermentation were investigated. There was a significant difference among the strains in terms of viable cell counts and proteolytic activity during fermentation (p < 0.05). The amount of syneresis was also different among the resulted gels as it was in the range from 61% (sample fermented with S. thermophilus ) to 69.5% (fermented with L. plantarum MCM4) . The main soy proteins were degraded to different extents as a function of fermentation time. Texture analysis showed that fermentation of soymilk with W. confusa MDM8 resulted in soy gel with higher firmness and consistency, while the sample fermented with L. plantarum MCM4 had higher adhesiveness and viscosity index. Overall, it can be concluded that L. plantarum MCM4, W. confusa MDM8, and S. thermophilus can be introduced as starter cultures for the production of novel soymilk gels with reasonable properties.

Nowadays, plant-based dairy alternatives have gained considerable attention. However, the textural and sensorial characteristics of plant-based products limit their acceptance. The exploitation of lactic acid bacteria has been proposed as a promising approach to developing plant-based dairy analogs. In this study, the performance of three proteolytic lactic acid bacteria in the induction of soymilk gelation was compared and their effects on the physicochemical properties of resulting gels were investigated. Lactiplantibacillus plantarum MCM4, Streptococcus thermophilus , and Weissella confusa MDM8 ) were inoculated to the soy milk matrix, and incubated at 37 °C until reaching pH 4.7. To understand the effects of acidifying and proteolytic activity of starter culture, syneresis, cell counts, free amino acid content (O-phthalaldehyde method), evaluation of proteolysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and textural parameters of soymilk gels during fermentation were investigated. There was a significant difference among the strains in terms of viable cell counts and proteolytic activity during fermentation (p < 0.05). The amount of syneresis was also different among the resulted gels as it was in the range from 61% (sample fermented with S. thermophilus ) to 69.5% (fermented with L. plantarum MCM4) . The main soy proteins were degraded to different extents as a function of fermentation time. Texture analysis showed that fermentation of soymilk with W. confusa MDM8 resulted in soy gel with higher firmness and consistency, while the sample fermented with L. plantarum MCM4 had higher adhesiveness and viscosity index. Overall, it can be concluded that L. plantarum MCM4, W. confusa MDM8, and S. thermophilus can be introduced as starter cultures for the production of novel soymilk gels with reasonable properties.

This article is from Computational and Structural Biotechnology Journal , volume 3 . Abstract Lactic acid bacteria (LAB) are receiving increased attention for use as cell factories for the production of metabolites with wide use by the food and pharmaceutical industries. The availability of efficient tools for genetic modification of LAB during the past decade permitted the application of metabolic engineering strategies at the levels of both the primary and the more complex secondary metabolism. The recent developments in the area with a focus on the production of industrially important metabolites will be discussed in this review.

The influence of ginger on Lactic Acid Bacteria (LAB) load / some probiotic properties, aflatoxin levels and acceptability of ogi (maize pap) co – fermented with ginger was studied. Various quantities (0, 4, 6, 8, and 10 grams) of fresh ginger were incorporated into 400 grams fermenting maize at the beginning of fermentation. Changes in Total Titratable Acidity (TTA), pH and LAB load were determined using standard procedures. Sensory evaluation was done using nine point hedonic scales. Enzyme Linked Immunosorbent Assay (ELISA) kit was used to determine the total aflatoxin level. Isolates were screened for probiotic properties and identified using standard procedures. The pH values ranged between 4.90 and 7.20 in non ginger fermenting maize (control) and from 3.80 – 7.10 in the ginger fermenting maize. TTA ranged between 0.11 % and 0.70 % in the control and from 0.12 – 0.72 % in the ginger fermenting maize. LAB population increase significantly at p < 0.05 and ranged from 3.0 x 104cfu/mL – 8.2.0 x 104cfu/mL in the control and from 3.3 x 104cfu/mL - 8.8 x 104cfu/mL in the ginger samples. LAB isolates were identified as Lactobacillus fermentum, L. plantarum, L. acidophilus and L. brevis and they possessed potentials to assimilate cholesterol except L. brevis. They were also able to withstand pH values of 2, 3, 4, and 7 and tolerate 0.1, 0.5 and 1.0 % bile concentrations after 24 h. Aflatoxin levels decreases significantly from 50 ppb to 2.0 ppb in control and to 1.8 ppb in the ginger samples. High quantity of ginger reduced acceptability. This study demonstrated that ginger has no negative effects on LAB and aflatoxin level reduction potential of LAB, its use as additive in ogi could be encouraged.

This article is from Frontiers in Microbiology , volume 4 . Abstract Lactic acid bacteria (LAB) are a diverse group of Gram-positive bacteria found in a vast array of environments including dairy products and the human gastrointestinal tract (GIT). In both niches, surface proteins play a crucial role in mediating interactions with the surrounding environment. The sortase enzyme is responsible for covalently coupling a subset of sortase-dependent proteins (SDPs) to the cell wall of Gram-positive organisms through recognition of a conserved C-terminal LPXTG motif. Genomic sequencing of LAB and annotation has allowed for the identification of sortase and SDPs. Historically, sortase and SDPs were predominately investigated for their role in mediating pathogenesis. Identification of these proteins in LAB has shed light on their important roles in mediating nutrient acquisition through proteinase P as well as positive probiotic attributes including adhesion, mucus barrier function, and immune signaling. Furthermore, sortase expression signals in LAB have been exploited as a means to develop oral vaccines targeted to the GIT. In this review, we examine the collection of studies which evaluate sortase and SDPs in select species of dairy-associated and health promoting LAB.

Microalgae have high nutritional value and bioactive compounds with functional potential, including a prebiotic effect. In this context, this study aims to evaluate, through systematic review and meta-analysis, the influence of microalgae on the modulation of lactic acid bacteria, recognized for their benefits to intestinal and immune health. We hope to gather and critically analyze the available evidence, identify patterns and gaps in the literature, providing support for future research and applications in functional foods.

The objective of this study was to improve the survival of lactic acid bacteria (LAB) in Tarhana soup as a non-dairy matrix. Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophiles were encapsulated in electrospun nanofiber mats fabricated from corn starch (CS) and sodium alginate (SA) and the protective effect of the nanofibers were investigated on the cells during the preparation of Tarhana and in the astrointestinal tract. The moisture content of the control and nanofiber- loaded dried Tarhana samples was 8.75 and 8.71%, respectively; therefore, using nanofiber mats in the formulation had no significant effect on he moisture content of the samples. A negative zeta potential value of -15.1 mV was found for LAB- loaded nanofibers. The nanofibers mats prepared from SA and CS mix showed a bead- free and clean structure with uniformity in size. The diameter size of most of the fibers ranged from 175- 338 with an average of 265 nm. Loading nanofiber mats with L. delbrueckii subsp. bulgaricus and S. thermophilus cells led to a uniform distributed beaded structure and the average diameter enhanced to approximately 763 nm. The viability of L. delbrueckii and S. thermophilus at the end of the electrospinning process was 92.82% and 95.83%, espectively, which indicating a slight loss in their population. Survival of nanoencapsulated S. thermophilus and L. delbrueckii was 93.50% and 89.16% respectively, while for free cells it was 85.3 and 76.4% that showed considerable protective effect of CS/SA fibers on the cells against dehydration of Tarhana medium. Nanofiber mats improved the stability of the cells against ordinary heat treatment used in preparing Tarhana soup. The survival rate of S. thermophilus was higher than L. delbrueckii subsp. bulgaricus and a significant difference was observed between the viability of free and nanoencapsulated bacteria. The survival of CS/SA nanoencapsulated S. thermophilus and L. delbrueckii subsp. bulgaricus was 83.25% and 80.21%, respectively, which is indicative of the significant protective effect of fibers on the cells against the heating process. The nanofibers also provided good stability for the cells in the gastrointestinal tract as 10  of the cells were survived which is within the recommended level of potential probiotic dose to be effective. There was no significant difference in the color of all samples. Nanoencapsulation in CS/ SA nanofiber mats mproved the protection of both LAB strains in simulated fluids of the stomach and intestine (Table 4). After continuous exposure to simulated gastrointestinal fluid, a significant loss of viable free LAB cells (higher than 4 log CFU/ml) was found while the population of S. thermophilus and L. delbrueckii subsp. bulgaricus encapsulated in CS/ SA nanofibers decreased only 0.45 and 0.37 log CFU after 120 min (p> 0.01), 0.93 and 0.80 log CFU after 180 min (p< 0.01), respectively. Tarhana soup prepared with probiotic– loaded nanofibers ained higher scores in terms of consistency, mouth feel, odor, taste, flavor, and overall acceptability attributes. Tarhana soup with nanofibers possessed much sour taste and flavor than samples prepared with free cells of probiotics. The results of the present study indicated that the protection obtained from CS/ SA capsules secured 6  to 10 7 CFUg-1 of the probiotic cells which are within the recommended level of probiotic dose to be functional in consumers’ body. Therefore, this product can be used by the consumers like vegetarians and lactose or milk peptide intolerants who do not consume dairy products but need potential fermented probiotic food.

This article is from Food Science & Nutrition , volume 2 . Abstract Fermented pastes of soybeans and soybean–maize blends were evaluated to determine sensory properties driving consumer liking. Pastes composed of 100% soybeans, 90% soybeans and 10% maize, and 75% soybeans and 25% maize were naturally fermented (NFP), and lactic acid bacteria fermented (LFP). Lactic acid bacteria fermentation was achieved through backslopping using a fermented cereal gruel, thobwa. Ten trained panelists evaluated intensities of 34 descriptors, of which 27 were significantly different (P 

This article is from Acta Crystallographica Section D: Biological Crystallography , volume 69 . Abstract The crystal structures of two 6-P-β-glucosidases from the GH1 family were determined in the apo form and in the presence of a 6′-P-salicin substrate, of the reaction product 6-P-β-glucose and of glucose corresponding to the aglycon molecule. The presence of natural ligands enabled the definition of the structural elements responsible for the recognition and hydrolysis of 6′-P-β-glucosides.

This article is from Brazilian Journal of Microbiology , volume 41 . Abstract Lactic acid bacteria (LAB) were isolated from ovine milk and cheeses manufactured in the South Region of Brazil. Among 112 bacterial isolates investigated, 59 were chosen through a screening for LAB. Among these 59 strains of LAB, 21% showed antimicrobial, proteolytic and lipolytic activities. Based on this screening, Lactobacillus plantarum LCN 17 and Lactobacillus rhamnosus LCN 43 were selected and tested for the production of bacteriocin-like substances (BLS). The BLS produced by both isolates showed antimicrobial activity against Listeria monocytogenes, whereas that produced by L. plantarum LCN 17 presented higher stability to different temperature, pH and enzyme treatments. These strains present potential for production of BLS, and for use as starter cultures.

Introduction   The food and water contamination with heavy metals is increasing due to the environmental pollutions. Heavy metals are the elements with the density of more than 5 g/cm 3 and have become a serious problem as a result of the urbanization and industrialization. These toxic metals pollute water, soil, plants, and eventually foodstuffs and our bodies. Several methods exist to remediate heavy metal pollution in waters such as membrane filtration, ion exchange mechanisms, or by precipitation. Yet, these techniques are not cost effective, in some cases, and do produce wastes that need to be properly disposed of. Microbial bioremediation could be an alternative. The use of microbes for remediation of heavy metals has been well studied. Some microorganisms, especially soil bacteria, have the ability to tolerate these contaminants. In addition, certain bacterial strains are capable of binding to heavy metals or transforming them into less toxic forms. Low operating costs, usable in foodstuffs, selective removal for specific toxic metals, minimal use of chemicals (resulting in low sludge production) and high efficiencies at very low levels of heavy metals are some of the advantages of biosorption methods. In this regard, the purpose of this study was to investigate the ability of active and passive absorption of heavy metals by a number of Lactic Acid Bacteria (LAB) strains in laboratory environment and food.   Materials and Methods   Seven LAB isolates including Lacticaseibacillus casei (RTCC 1296-3), Lacticaseibacillus rhamnosus (RTCC 1293-2), Lactiplantibacillus plantarum (RTCC 1290), Limosilactobacillus fermentum (RTCC 1303), Enterococcus faecium (RTCC 2347), Lactobacillus helveticus (RTCC 1304) and Lactobacillus acidophilus (RTCC 1299) were obtained from Razi type culture collection (RTCC), located at Razi vaccine and Serum Research Institute, Iran. All isolates were cultured in MRS (Scharlau, Spain) broth medium, at 37 °C for 24 hours, under anaerobic conditions. Pure cultures were preserved for long term by freezing at -70°C with 20% Glycerol. Heavy metals including Nitrate of Pb (II) , Cd (II) and Ni (II) were purchased from Merck (Darmstadt, Germany). All standard solutions were prepared from the stock solutions containing 1000 mgl -1 in distilled water. Other chemicals used in study including Nitric acid (65%) and Hydrogen peroxide (37%), were also purchased from Merck, Germany. This study was conducted in two in- vitro and in-vivo phases; in the in- vitro phase, seven strains of bacteria with probiotic properties ( L. casei, L. rhamnosus, L. plantarum, L. fermentum, Ent. facium, L. helveticus and L. acidofilous ) were screened and then their ability to bind to cadmium (Cd), Lead (Pb) and nickel (Ni) in aqueous solution was investigated. Then, in the in-vivo stage, three probiotic strains that had the highest biosorption efficiency in the previously stage were selected and their effect with a ratio of 1:1:1 and contact time of 15 and 30 minutes on the removal of these toxic metals in coriander, leek and parsley fresh vegetables was evaluated. The residual concentrations of heavy metals in solution were measured by Inductively Coupled Plasma Mass Spectrometer (ICP-MS; ELAN DRC-e, PerkinElmer SCIEX, Canada) and Morphology of bacteria cell surfaces incubated with metals were monitored by scanning electron microscopy (JEOL JSM 5400 LV, Japan).   Results and Discussion The results of the in vitro stage showed that the most ability to heavy metals adsorption was related to the Ent. Facium bacterium which were equal to 79.75±0.11, 75.28±0.05 and 83.99±0.10% for Pb, Cd and Ni, respectively.   In general, the removal efficiency of heavy metals by LAB bacteria in the inactive and killed state was significantly higher than the active removal efficiency of these bacteria, so that the highest percentage of passive absorption of lead, cadmium and nickel metals by inactive strains of L. casei, L. plantarum and Ent. Facium were 90.01, 81.98 and 86.56%, respectively. Electron microscopy observations and energy dispersive X-ray (EDX) analysis confirmed that the majority of these toxic metals significantly damage the surface of living cells by accumulating and binding on the surface of bacterial cells. A combination of three bacterial strains had a synergistic effect on the binding properties of toxic metals compared to the single state of these bacteria, so that in both active and inactive states, 90-99% of heavy metals from edible leafy vegetables were removed in less than 15 minutes. The results of this research generally showed that the binding capacity of dead biomass is significantly high and it is possible to dispose and reuse biomass in case of biological absorption.  

This article is from BMC Infectious Diseases , volume 11 . Abstract Background: Hydrogen peroxide (H2O2) produced by vaginal lactobacilli is generally believed to protect against bacteria associated with bacterial vaginosis (BV), and strains of lactobacilli that can produce H2O2 are being developed as vaginal probiotics. However, evidence that led to this belief was based in part on non-physiological conditions, antioxidant-free aerobic conditions selected to maximize both production and microbicidal activity of H2O2. Here we used conditions more like those in vivo to compare the effects of physiologically plausible concentrations of H2O2 and lactic acid on a broad range of BV-associated bacteria and vaginal lactobacilli. Methods: Anaerobic cultures of seventeen species of BV-associated bacteria and four species of vaginal lactobacilli were exposed to H2O2, lactic acid, or acetic acid at pH 7.0 and pH 4.5. After two hours, the remaining viable bacteria were enumerated by growth on agar media plates. The effect of vaginal fluid (VF) on the microbicidal activities of H2O2 and lactic acid was also measured. Results: Physiological concentrations of H2O2 ( < 100 μM) failed to inactivate any of the BV-associated bacteria tested, even in the presence of human myeloperoxidase (MPO) that increases the microbicidal activity of H2O2. At 10 mM, H2O2 inactivated all four species of vaginal lactobacilli but only one of seventeen species of BV-associated bacteria. Moreover, the addition of just 1% vaginal fluid (VF) blocked the microbicidal activity of 1 M H2O2. In contrast, lactic acid at physiological concentrations (55-111 mM) and pH (4.5) inactivated all the BV-associated bacteria tested, and had no detectable effect on the vaginal lactobacilli. Also, the addition of 10% VF did not block the microbicidal activity of lactic acid. Conclusions: Under optimal, anaerobic growth conditions, physiological concentrations of lactic acid inactivated BV-associated bacteria without affecting vaginal lactobacilli, whereas physiological concentrations of H2O2 produced no detectable inactivation of either BV-associated bacteria or vaginal lactobacilli. Moreover, at very high concentrations, H2O2 was more toxic to vaginal lactobacilli than to BV-associated bacteria. On the basis of these in vitro observations, we conclude that lactic acid, not H2O2, is likely to suppress BV-associated bacteria in vivo.

This article is from Brazilian Journal of Microbiology , volume 41 . Abstract The effect of different fermenting microorganisms on growth of a mycotoxin- producing Aspergillus nomius was assayed. Two lactic acid bacteria, Lactobacillus fermentum and Lactobacillus rhamnosus, and Saccharomyces cerevisiae, all of which are widely used in fermentation and preservation of food, were assayed on their fungus inhibitory properties. Assays were carried out by simultaneous inoculation of one of the possible inhibiting microorganisms and the fungus or subsequent inoculation of one of the microorganisms followed by the fungus. All three microorganisms assayed showed growth inhibition of the mycotoxin-producing Aspergillus strain. L. rhamnosus O236, isolated from sheep milk and selected for its technological properties, showed highest fungal inhibition of the microorganisms assayed. The use of antifungal LAB with excellent technological properties rather than chemical preservatives would enable the food industry to produce organic food without addition of chemical substances.

This article is from Microbial Cell Factories , volume 12 . Abstract Background: In the last decade, several studies described the promising cytotoxic activity of fermented wheat germ towards cancer cell lines and during in vivo clinical trials. Recent data suggested that the antiproliferative, antimetastatic and immunological effects of this preparation are mainly attributed to quinones. This study aimed at exploiting the potential of sourdough lactic acid bacteria fermentation to release 2-methoxy benzoquinone, and 2,6-dimethoxybenzoquinone, which are naturally present in wheat germ as glycosylated and non-physiologically active form. Results: Preliminarily, forty strains of lactic acid bacteria, previously isolated from wheat germ, were in vitro screened based on β-glucosidase activity. Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5 were selected based on the highest enzyme activity and on technology features. These strains were used in combination to ferment wheat germ. Raw wheat germ, without bacterial inoculum, was subjected to the same incubation and used as the control. The sourdough fermented wheat germ was characterized based on microbiological, physico-chemical and biochemical features. During incubation, the release of the non-glycosylated and physiologically active 2-methoxy benzoquinone, and 2,6-dimethoxybenzoquinone was almost completed during 24 h. Compared to the control, the concentration of the above bioactive compounds increased almost 4 and 6-folds. Both raw wheat germ (control) and sourdough fermented wheat germ were ex vivo assayed for the anti-proliferative activity towards various cell lines of germ cell tumor, colon carcinoma and ovarian carcinoma. While no effect was found for the raw wheat germ, the sourdough fermented preparation markedly and variously affected the human tumor cell lines. The values of IC50 ranged from 0.105 ± 0.005 to 0.556 ± 0.071 mg/ml, with a median value of IC50 of 0.302 mg/ml. Conclusions: These results are comparable to those found for other well-known pharmaceutical preparations, and may disclose the use of the sourdough fermented wheat germ as an ingredient, nutritional supplement and/or anticancer drug.

Abstract — Honey bee hives are influenced by many different biotic and abiotic factors. Several studies demonstrate that the presence of the lactic acid producing bacteria such as Lactobacillus, Bifidobacterium, and Leuconostoc in honey bee intestinal tracts has a positive effect on a bee hive’s health. Bee hives which are lacking beneficial microflora could be supplied with it through a carrier media. The aim of this study was to evaluate several concentrations of inverted sugar syrup’s suitability for carrying lactic acid bacteria for possible enhancement of honey bee microflora by using lactic bacteria strains previously isolated from honey bee gastrointestinal tract in Latvian apiaries. Since sugar syrup is commonly used for feeding honey bees during the wintering it was decided to use it as a ca rrier media. There were five isolates of lactic acid bacteria used to test three concentrations of sugar syrup and it was found out that the inverted sugar syrup concentration of 25% is most suitable for carrying tested isolates judged by their growth dynamics and attraction from the bees.

This article is from Journal of Translational Medicine , volume 11 . Abstract Background: Secondary hyperoxaluria either based on increased intestinal absorption of oxalate (enteric), or high oxalate intake (dietary), is a major risk factor of calcium oxalate urolithiasis. Oxalate-degrading bacteria might have beneficial effects on urinary oxalate excretion resulting from decreased intestinal oxalate concentration and absorption. Methods: Twenty healthy subjects were studied initially while consuming a diet normal in oxalate. Study participants were then placed on a controlled oxalate-rich diet for a period of 6 weeks. Starting with week 2 of the oxalate-rich diet, participants received 2.6 g/day of a lactic acid bacteria preparation for 5 weeks. Finally, subjects were examined 4 weeks after treatment while consuming again a normal-oxalate diet. Participants provided weekly 24-hour urine specimens. Analyses of blood samples were performed before and at the end of treatment. Results: Urinary oxalate excretion increased significantly from 0.354 ± 0.097 at baseline to 0.542 ± 0.163 mmol/24 h under the oxalate-rich diet and remained elevated until the end of treatment, as did relative supersaturation of calcium oxalate. Plasma oxalate concentration was significantly higher after 5 weeks of treatment compared to baseline. Four weeks after treatment, urinary oxalate excretion and relative supersaturation of calcium oxalate fell to reach initial values. Conclusions: Persistent dietary hyperoxaluria and increased plasma oxalate concentration can already be induced in healthy subjects without disorders of oxalate metabolism. The study preparation neither reduced urinary oxalate excretion nor plasma oxalate concentration. The preparation may be altered to select for lactic acid bacteria strains with the highest oxalate-degrading activity.

This article is from BMC Microbiology , volume 12 . Abstract Background: Indigenous fermented food products play an essential role in the diet of millions of Africans. Lactic acid bacteria (LAB) are among the predominant microbial species in African indigenous fermented food products and are used for different applications in the food and biotechnology industries. Numerous studies have described antimicrobial susceptibility profiles of LAB from different parts of the world. However, there is limited information on antimicrobial resistance profiles of LAB from Africa. The aim of this study was to characterize 33 LAB previously isolated from three different African indigenous fermented food products using (GTG)5-based rep-PCR, sequencing of the 16S rRNA gene and species-specific PCR techniques for differentiation of closely related species and further evaluate their antibiotic resistance profiles by the broth microdilution method and their haemolytic activity on sheep blood agar plates as indicators of safety traits among these bacteria. Results: Using molecular biology based methods and selected phenotypic tests such as catalase reaction, CO2 production from glucose, colonies and cells morphology, the isolates were identified as Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus ghanensis, Lactobacillus plantarum, Lactobacillus salivarius, Leuconostoc pseudomesenteroides, Pediococcus acidilactici, Pediococcus pentosaceus and Weissella confusa. The bacteria were susceptible to ampicillin, chloramphenicol, clindamycin and erythromycin but resistant to vancomycin, kanamycin and streptomycin. Variable sensitivity profiles to tetracycline and gentamicin was observed among the isolates with Lb. plantarum, Lb. salivarius, W. confusa (except strain SK9-5) and Lb. fermentum strains being susceptible to tetracycline whereas Pediococcus strains and Lb. ghanensis strains were resistant. For gentamicin, Leuc. pseudomesenteroides, Lb. ghanensis and Ped. acidilactici strains were resistant to 64 mg/L whereas some W. confusa and Lb. plantarum strains had a MIC value of 16 mg/L and 32 mg/L respectively. No β-haemolytic activity was observed, however, α-haemolytic activity was observed in 27% (9) of the strains comprising Lb. salivarius (6), W. confusa (2) and Lb. delbrueckii (1) isolates. Conclusions: The resistance to kanamycin and vancomycin is probably an intrinsic feature since similar observations were reported in the literature for LAB. Low prevalence of pathogenicity indicator traits were observed among the isolates especially with the presence of poor haemolytic activities and they could therefore be considered as interesting candidates for selection of starter cultures or probiotics for different applications.

This article is from The EPMA Journal , volume 5 . Abstract None

This article is from Toxins , volume 6 . Abstract Paralytic shellfish toxins (PSTs) are non-protein neurotoxins produced by saltwater dinoflagellates and freshwater cyanobacteria. The ability of Lactobacillus rhamnosus strains GG and LC-705 (in viable and non-viable forms) to remove PSTs (saxitoxin (STX), neosaxitoxin (neoSTX), gonyautoxins 2 and 3 (GTX2/3), C-toxins 1 and 2 (C1/2)) from neutral and acidic solution (pH 7.3 and 2) was examined using HPLC. Binding decreased in the order of STX ~ neoSTX > C2 > GTX3 > GTX2 > C1. Removal of STX and neoSTX (77%–97.2%) was significantly greater than removal of GTX3 and C2 (33.3%–49.7%). There were no significant differences in toxin removal capacity between viable and non-viable forms of lactobacilli, which suggested that binding rather than metabolism is the mechanism of the removal of toxins. In general, binding was not affected by the presence of other organic molecules in solution. Importantly, this is the first study to demonstrate the ability of specific probiotic lactic bacteria to remove PSTs, particularly the most toxic PST-STX, from solution. Further, these results warrant thorough screening and assessment of safe and beneficial microbes for their usefulness in the seafood and water industries and their effectiveness in vivo.

This article is from Bioscience of Microbiota, Food and Health , volume 33 . Abstract In the present work, five hundred and sixty-seven isolates of lactic acid bacteria were recovered from raw bee pollen grains. All isolates were screened for their antagonistic activity against both Gram-positive and Gram-negative pathogenic bacteria. Neutralized supernatants of 54 lactic acid bacteria (LAB) cultures from 216 active isolates inhibited the growth of indicator bacteria. They were phenotypically characterized, based on the fermentation of 39 carbohydrates. Using the simple matching coefficient and unweighted pair group algorithm with arithmetic averages (UPGMA), seven clusters with other two members were defined at the 79% similarity level. The following species were characterized: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Pediococcus acidilactici, Pediococcus pentosaceus, and unidentified lactobacilli. Phenotypic characteristics of major and minor clusters were also identified. Partial sequencing of the 16S rRNA gene of representative isolates from each cluster was performed, and ten strains were assigned to seven species: Lactobacillus plantarum, Lactobacillus fermentum, Lactococcus lactis, Lactobacillus ingluviei, Pediococcus pentosaceus, Lactobacillus acidipiscis and Weissella cibaria. The molecular method used failed to determine the exact taxonomic status of BH0900 and AH3133.

This article is from PLoS ONE , volume 9 . Abstract Hyperuricemia is well known as the cause of gout. In recent years, it has also been recognized as a risk factor for arteriosclerosis, cerebrovascular and cardiovascular diseases, and nephropathy in diabetic patients. Foods high in purine compounds are more potent in exacerbating hyperuricemia. Therefore, the development of probiotics that efficiently degrade purine compounds is a promising potential therapy for the prevention of hyperuricemia. In this study, fifty-five lactic acid bacteria isolated from Chinese sauerkraut were evaluated for the ability to degrade inosine and guanosine, the two key intermediates in purine metabolism. After a preliminary screening based on HPLC, three candidate strains with the highest nucleoside degrading rates were selected for further characterization. The tested biological characteristics of candidate strains included acid tolerance, bile tolerance, anti-pathogenic bacteria activity, cell adhesion ability, resistance to antibiotics and the ability to produce hydrogen peroxide. Among the selected strains, DM9218 showed the best probiotic potential compared with other strains despite its poor bile resistance. Analysis of 16S rRNA sequences showed that DM9218 has the highest similarity (99%) to Lactobacillus plantarum WCFS1. The acclimated strain DM9218-A showed better resistance to 0.3% bile salt, and its survival in gastrointestinal tract of rats was proven by PCR-DGGE. Furthermore, the effects of DM9218-A in a hyperuricemia rat model were evaluated. The level of serum uric acid in hyperuricemic rat can be efficiently reduced by the intragastric administration of DM9218-A (P

This article is from Microbial Cell Factories , volume 13 . Abstract The food industry is constantly striving to develop new products to fulfil the ever changing demands of consumers and the strict requirements of regulatory agencies. For foods based on microbial fermentation, this pushes the boundaries of microbial performance and requires the constant development of new starter cultures with novel properties. Since the use of ingredients in the food industry is tightly regulated and under close scrutiny by consumers, the use of recombinant DNA technology to improve microbial performance is currently not an option. As a result, the focus for improving strains for microbial fermentation is on classical strain improvement methods. Here we review the use of these techniques to improve the functionality of lactic acid bacteria starter cultures for application in industrial-scale food production. Methods will be described for improving the bacteriophage resistance of specific strains, improving their texture forming ability, increasing their tolerance to stress and modulating both the amount and identity of acids produced during fermentation. In addition, approaches to eliminating undesirable properties will be described. Techniques include random mutagenesis, directed evolution and dominant selection schemes.

  Introduction [1] : European honey bees  (Apis mellifera ) are the most important pollinator insects that play vital role in maintenance of all most all life forms on earth. However, over the last decade major concerns have raised due to decline in the population of these insect species. A variety of factors have been responsible for these concerns of which the most important is honey bee bacterial diseases like Nosemosis (Nosema), American and European foulbrood diseases. While, overuse of antibiotics utilized for the treatment and control of these diseases has resulted in the emergence of antibiotic resistant strains of these pathogens. Probiotics have been considered a suitable substitute of antibiotics in human and animals. In last several years, lactobacillus species isolated from honeybees have been considered of significance in enhancing the life span of honeybees by reducing the incidence of bacterial and viral infections in these tiny insects. Among the isolated microbes in the gut of honeybees, Lactic Acid Bacteria (LAB) are of utmost importance showing direct impacts on the health of their host by modulating the gut microbial flora and are termed as Probiotic bacteria. T he objective of this research was to isolate and identify LAB from different parts of the intestinal tract of honeybees Apis mellifera and to characterize their probiotic properties. Materials and Methods: Twenty-four honeybees collected from the hives located in the city of karaj were analyzed for the presence of LAB species. The stomach contents of honeybees were inoculated into MRS broth, incubated at 37ºCfor 48 hrs. The obtained colonies were purified and identified to species levels phenotypically and geno-typically. Hemolytic activity and sugar fermentation reactions of the isolates were recorded and later subjected 16SrRNA sequencing using a pair of universal primers. The identified isolates were evaluated for their viability in acidic conditions at pH 2.5, 3.0, 4.0 and 6.5 at different time intervals. Bile resistance of the isolates was tested by culturing the isolates in the presence of different concentrations of the said salts (0.5, 0.7 and 1%). Survival of LAB isolates in simulated gastric and intestinal conditions containing different enzymes and bile salts, antibacterial spectrum against a number of gram positive and gram-negative pathogens by agar well diffusion assay, and their in vitro colonization ability (aggregation, co-aggregation and hydrophobicity percentages) were evaluated. The results were analyzed statistically. Results and Discussion : Twenty nine gram positive, catalase negative and non-hemolytic colonies were isolated from 24 honeybee samples. Among these, only 7 colonies showed enhanced antibacterial activity and were selected for further studies. Based on phenotypic characteristics, sugar fermentation reactions and 16S rRNA sequencing the isolates were identified as Lactobacillus acidophilus (1), Lacticaseiobacillus casei, Lactiplantibacillus plantarum (2), Lactobacillus apis (1), Enterococcus faecium (1) and Pediococcus acidilactici (1). During probiotic characterizations, the identified isolates were shown to retain their viability in acidic conditions and resisted pH 2.5, 3 and 4 for more than 4 hrs. However, slight decrease in viability at pH 2.5 and 3.0 was observed, compared to pH 4.0 and above. All isolates appeared bile resistant and tolerated all used concentrations of bile salts during 8 hrs of incubation. Survival rate of the isolates in simulated intestinal conditions was significantly (p˂0.05) greater compared to simulated gastric conditions indicating greater stability of the isolates to alkaline conditions rather than to acidic conditions. L.acidophilus and E.faecium showed least resistance in gastric conditions and their growth rate was decreased more than 50% under said conditions. In contrast, the growth rate of these two isolates was highest in simulated intestinal conditions as they resisted these conditions for more than 24 hours.   The isolates demonstrated antibacterial affect against a number of tested pathogens including Listeria monocytogenes, Escherichia coli, Enterococcus faecalis and Streprtococcus mutans. The auto-aggregation, and cell surface hydrophobicity percentages of L.casei appeared highest compared to other tested Lactic Acid bacteria in study (p˂0.05), while, L.apis showed the highest co-aggregation with S.typhi strain. P.acidilactici possessed the least auto-aggregation (46%), co-aggregation (10%) and hydrophobicity (43%) percentage. Auto-aggregation ability appeared directly related to hydrophobicity percentages and isolates showing high aggregation ability also showed high hydrophobicity %. Conclusions: In conclusion, honeybee gut appeared a reservoir of LAB with probiotic potential. It is suggested that further studies should be conducted in order to determine the health benefits of these LABs in honeybees, with especial emphasis on their ability to prevent honeybee diseases.

This article is from BMC Microbiology , volume 13 . Abstract Background: Lactic acid bacteria (LAB) has been considered a beneficial bacterial group, found as part of the microbiota of diverse hosts, including humans and various animals. However, the mechanisms of how hosts and LAB interact are still poorly understood. Previous work demonstrates that 13 species of Lactobacillus and Bifidobacterium from the honey crop in bees function symbiotically with the honeybee. They protect each other, their hosts, and the surrounding environment against severe bee pathogens, bacteria, and yeasts. Therefore, we hypothesized that these LAB under stress, i.e. in their natural niche in the honey crop, are likely to produce bioactive substances with antimicrobial activity. Results: The genomic analysis of the LAB demonstrated varying genome sizes ranging from 1.5 to 2.2 mega-base pairs (Mbps) which points out a clear difference within the protein gene content, as well as specialized functions in the honeybee microbiota and their adaptation to their host. We demonstrate a clear variation between the secreted proteins of the symbiotic LAB when subjected to microbial stressors. We have identified that 10 of the 13 LAB produced extra-cellular proteins of known or unknown function in which some are arranged in interesting putative operons that may be involved in antimicrobial action, host interaction, or biofilm formation. The most common known extra-cellular proteins secreted were enzymes, DNA chaperones, S-layer proteins, bacteriocins, and lysozymes. A new bacteriocin may have been identified in one of the LAB symbionts while many proteins with unknown functions were produced which must be investigated further. Conclusions: The 13 LAB symbionts likely play different roles in their natural environment defending their niche and their host and participating in the honeybee’s food production. These roles are partly played through producing extracellular proteins on exposure to microbial stressors widely found in natural occurring flowers. Many of these secreted proteins may have a putative antimicrobial function. In the future, understanding these processes in this complicated environment may lead to novel applications of honey crop LAB proteins.

Aim: The aim of this study is creation of sustainable consortium of symbiotic probiotic bacteria with high colonization potential for rapid response to vaginal acute and chronic challenges. Material and method: In this study used biocompatible lactobacilli and cocci possessing high antimicrobial activity, isolated previously from vaginal samples of healthy women from 20 to 45 years old from Armenia. The following methods: screening of antimicrobial activity, microbial adhesion to solvents, auto aggregation and co aggregation assays were used Statistical analysis used: Student's test computer, taking the criterion of P

This article is from Microbial Cell Factories , volume 13 . Abstract The cell wall of Gram-positive bacteria is a complex assemblage of glycopolymers and proteins. It consists of a thick peptidoglycan sacculus that surrounds the cytoplasmic membrane and that is decorated with teichoic acids, polysaccharides, and proteins. It plays a major role in bacterial physiology since it maintains cell shape and integrity during growth and division; in addition, it acts as the interface between the bacterium and its environment. Lactic acid bacteria (LAB) are traditionally and widely used to ferment food, and they are also the subject of more and more research because of their potential health-related benefits. It is now recognized that understanding the composition, structure, and properties of LAB cell walls is a crucial part of developing technological and health applications using these bacteria. In this review, we examine the different components of the Gram-positive cell wall: peptidoglycan, teichoic acids, polysaccharides, and proteins. We present recent findings regarding the structure and function of these complex compounds, results that have emerged thanks to the tandem development of structural analysis and whole genome sequencing. Although general structures and biosynthesis pathways are conserved among Gram-positive bacteria, studies have revealed that LAB cell walls demonstrate unique properties; these studies have yielded some notable, fundamental, and novel findings. Given the potential of this research to contribute to future applied strategies, in our discussion of the role played by cell wall components in LAB physiology, we pay special attention to the mechanisms controlling bacterial autolysis, bacterial sensitivity to bacteriophages and the mechanisms underlying interactions between probiotic bacteria and their hosts.