Ability Of Lactic Acid Bacteria Research Articles

Differences in the Ability of Lactic Acid Bacteria To Prevent Acute Alcohol-Induced Liver Injury via the Gut Microbiota-Bile Acid-Liver Axis.

Probiotics can regulate gut microbiota and protect against acute alcohol-induced liver injury through the gut-liver axis. However, efficacy is strain-dependent, and their mechanism remains unclear. This study investigated the effect of lactic acid bacteria (LAB), including Lacticaseibacillus paracasei E10 (E10), Lactiplantibacillus plantarum M (M), Lacticaseibacillus rhamnosus LGG (LGG), Lacticaseibacillus paracasei JN-1 (JN-1), and Lacticaseibacillus paracasei JN-8 (JN-8), on the prevention of acute alcoholic liver injury in mice. We found that LAB pretreatment reduced serum alanine transaminase (ALT) and aspartate transaminase (AST) and reduced hepatic total cholesterol (TC) and triglyceride (TG). JN-8 pretreatment exhibited superior efficacy in improving hepatic antioxidation. LGG and JN-8 pretreatment significantly attenuated hepatic and colonic inflammation by decreasing the expression of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) and increasing the expression of interleukin 10 (IL-10). JN-1 and JN-8 pretreatments have better preventive effects than other LAB pretreatment on intestinal barrier dysfunction. In addition, the LAB pretreatment improved gut microbial dysbiosis and bile acid (BA) metabolic abnormality. All of the strains were confirmed to have bile salt deconjugation capacities in vitro, where M and JN-8 displayed higher activities. This study provides new insights into the prevention and mechanism of LAB strains in preventing acute alcoholic liver injury.

Відбір пробіотичних мікроорганізмів та їх композицій як основи для лінійки функціональних продуктів харчування з гіпохолестеринемічними властивостями

In modern clinical practice, the main methods for correcting elevated serum cholesterol levels are drugs that block the activity of the enzyme hydroxymethylglutaracyl-CoA-reductase (HMG-CoA-reductase) – statins or drugs that inhibit the absorption of cholesterol and sterols in the intestines ezetimibe. All hypocholesterolemic drugs are rather expensive and have side effects, the main of which is hepatotoxicity. During mono- and combined therapy with HMG-CoA reductase inhibitors and ezetimibe, cases of increased activity of alanine and asparagine transaminases (biochemical indicator of cytolytic syndrome), disorders of the digestive and respiratory systems, the central and peripheral nervous systems, and the sense organs along with weight gain, etc. have been found. Scientific literature has increasingly reported on the ability of lactic acid bacteria to lower serum cholesterol. The ability of certain strains of representatives of the normal microbiota to assimilate and precipitate deconjugated bile acids, as well as to destroy, bind, and assimilate cholesterol, is the basis of their hypocholesterolemic activity (the ability to reduce the level of serum cholesterol). A high level of cholesterol, both in the total blood serum and in low-density lipoproteins, is one of the main risk factors for coronary heart disease, atherosclerosis, cerebrovascular atherosclerosis, hypertension, tumors of the digestive tract, etc. The aim of the study was to establish the hypocholesterolemic activity in vitro and in vivo of previously selected highly effective probiotic strains of lactic- and bifidobacteria for the further creation on their basis of a line of effective functional food with hypocholesterolemic activity for the prevention and concomitant treatment of pathological conditions associated with high cholesterol levels. Methods. Bacterial hypocholesterolemic activity in vitro was determined according to Rudel L.L. and in vivo – on the mice model that was designed by us. Two schemes of the administration of probiotic strains – the prophylactic and therapeutic ones–were developed. Results showed that Lactobacillus acidophilus IMV B-7279 and Bifidobacterium animalis IMV B-7286 strains, as well as the Bifidobacterium animalis IMV B-7286: Bifidobacterium animalis IMV B-7285 (1:1) composition were the most effective probiotics used for treatment of mice with hypercholesterolemia. The cholesterol-lowering activity of all studied probiotic strains and their compositions ranged between 40–78 %. At the same time, it should be noted that the hypocholesterolemic activity of the other studied strains was not lower, and in some cases even higher than that of most of the drugs currently used for cholesterinosis. Conclusions. The obtained results allow us to assert that it is necessary to develop a series of functional foods and probiotics based on the studied strains and their compositions in an encapsulated form, for the prevention and treatment of diseases associated with the negative manifestations of high cholesterol levels.

Identification of novel probiotic lactic acid bacteria from soymilk waste using the 16s rRNA gene for potential use in poultry.

In-feed antibiotics have been used as antibiotic growth promoters (AGPs) to enhance the genetic potential of poultry. However, the long-term use of AGPs is known to lead to bacterial resistance and antibiotic residues in poultry meat and eggs. To address these concerns, alternatives to AGPs are needed, one of which is probiotics, which can promote the health of livestock without having any negative effects. In vitro probiotic screening was performed to determine the ability of lactic acid bacteria (LAB) isolated from soymilk waste to be used as a probiotic for livestock. Four LAB isolates (designated F4, F6, F9, and F11) isolated from soymilk waste were used in this study. In vitro testing was performed on LAB isolates to determine their resistance to temperatures of 42°C, acidic pH, bile salts, hydrophobicity to the intestine, and ability to inhibit pathogenic bacteria. A promising isolate was identified using the 16S rRNA gene. All LAB isolates used in this study have the potential to be used as probiotics. On the basis of the results of in vitro testing, all isolates showed resistance to temperatures of 42°C and low pH (2.5) for 3 h (79.87%-94.44%) and 6 h (76.29%-83.39%), respectively. The survival rate at a bile salt concentration of 0.3% ranged from 73.24% to 90.39%, whereas the survival rate at a bile salt concentration of 0.5% ranged from 56.28% to 81.96%. All isolates showed the ability to attach and colonize the digestive tract with a hydrophobicity of 87.58%-91.88%. Inhibitory zones of LAB against pathogens ranged from 4.80-15.15 mm against Staphylococcus aureus, 8.85-14.50 mm against Salmonella enteritidis, and 6.75-22.25 mm against Escherichia coli. Although all isolates showed good ability as probiotics, isolate F4 showed the best probiotic ability. This isolate was identified as Lactobacillus casei strain T22 (JQ412731.1) using the 16S rRNA gene. All isolates in this study have the potential to be used as probiotics. However, isolate F4 has the best probiotic properties and is considered to be the most promising novel probiotic for poultry.

Addition of glutamine to milk during fermentation by individual strains of lactic acid bacteria and the effects on pyroglutamic and butyric acid

Lactic acid bacteria fermentation generates pyroglutamic and butyric acid, two metabolites that influence the flavour of foods and could significantly benefit human health. In literature, data on the ability of lactic acid bacteria to produce these molecules is limited. Therefore, in this study, single strains were inoculated in milk to determine the quantity of butyric and pyroglutamic acid produced and the effect of glutamine enrichment substrate was evaluated. In addition to Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, which are used in traditional yoghurt, other strains (including some probiotics) isolated from different sources were studied. L. bulgaricus E1 and the probiotic L. casei ATCC393 generated the most butyric acid (110 and 108 mg 100 g−1 d.m., respectively) in media without glutamine. The highest quantity of pyroglutamic acid was produced by Lactobacillus delbruekii subsp. bulgaricus MY (700 mg 100 g−1 d.m.) and the probiotic Lacticaseibacillus casei Shirota (1786 mg 100 g−1 d.m.), respectively. Most of the inoculated strains produced a greater quantity of pyroglutamic acid in the substrate with glutamine. These results are an interesting starting point for researchers to utilize selected strains of lactic acid bacteria to develop new dairy products with functional properties due to the presence of pyroglutamic and butyric acid.

The SlpX protein plays a crucial role in the intestinal juice tolerance of Lactobacillus acidophilus CICC6074

The survival ability of lactic acid bacteria (LAB) in the gastrointestinal tract is low, and the mechanism of LAB resistance to the gastrointestinal tract's harsh environment is unclear. Therefore, this study used simulated gastrointestinal juices in vitro and transcriptomics approaches to identify proteins in Lactobacillus acidophilus CICC6074 that can enhance the strain's tolerance to gastrointestinal juices and verify the function of the target proteins. The results showed that the survival rate of Lactobacillus acidophilus CICC6074 was 79.24% after 6 h of in vitro intestinal juice treatment, and there were 10 genes coding proteins with significant changes in expression, among which S-layer protein gene slpX was significantly up-regulated. After overexpression of the slpX gene, the survival rate of Lactobacillus acidophilus CICC6074 was 94.35% after 6 h of in vitro intestinal juice tolerance. In conclusion, the SlpX protein plays a crucial role under the simulated intestinal juice condition of Lactobacillus acidophilus CICC6074. This study provides a basis for a deeper understanding of the survival mechanisms of Lactobacillus acidophilus in the gastrointestinal tract.

Importance of Lactic Acid Bacteria as an Emerging Group of Plant Growth-Promoting Rhizobacteria in Sustainable Agroecosystems

Increasing awareness of the problems caused by synthetic agrochemicals, such as chemical fertilizers, pesticides, and herbicides, makes it crucial to discover substitute approaches that can guarantee competitive plant production and protect the environment while maintaining the natural balance in agroecosystems. One of the leading alternatives is utilizing rhizobacterial strains named plant growth-promoting rhizobacteria (PGPR). The utilization of PGPR-based biofertilizers for advancement in the sustainability of farming productions has received considerable critical attention all over the world because of their contribution to not only improving plant growth but also inducing biotic and abiotic stress tolerance. This review updates the aforementioned eco-friendly strategy in sustainable agroecosystems and provides new insights into the phytostimulation and bioprotection ability of lactic acid bacteria (LAB), an emerging taxon of PGPR. In this regard, the ability of LAB to synthesize metabolites, including organic acids, phenolic acids and their flavonoid derivatives, phytohormones, and antimicrobial substrates, is presented. The use of LAB provides a bridge between PGPR and environmentally friendly crop productivity, which can lead to sustainable production systems by reducing the use of agrochemicals, improving soil quality, and minimizing environmental pollution. All the beneficial aspects of LAB need to be addressed by future research to plan systematic methodologies for their use and/or to combine the use of PGPR along with other organic or inorganic inputs in sustainable production systems.

Isolation, selection and characterisation of microorganisms with potential to form unique consortium for wine production

This paper focuses on a selection of microorganisms that should eventually form a Defined Consortium of Wine Microorganisms. The consortium might serve as a sophisticated oenological product for the production of wine with attractive organoleptic features. The Defined Consortium of Wine Microorganisms was obtained from non-saccharomyces and saccharomyces yeasts and lactic acid bacteria isolated from places where autochthonous microflora can be expected to occur (grape berries, wine lees or cellar spaces). A total of 42 microorganisms were obtained by surface smears, fallouts from the air or isolation from fermented must. All isolates were then tested and the best strains were selected on the basis of technological and phenotypic characterization using standard microbiological techniques. The main criteria for the selection of strains were the ability to ferment and the production of organoleptically active compounds. Sulphur dioxide or ethanol tolerance, β-glucosidase activity, a taxonomic identification, the tendency to produce sulphane or the ability of lactic acid bacteria to perform malolactic fermentation were also considered. According to these results, the non-saccharomyces yeast Starmerella bacillaris, the saccharomyces yeast Saccharomyces cerevisiae and the lactic acid bacterium Levilactobacillus brevis were selected as part of the Defined Consortium of Wine Microorganisms.

AFM1 exposure in male balb/c mice and intervention strategies against its immuno-physiological toxicity using clay mineral and lactic acid bacteria alone or in combination

Context Aflatoxins are the most harmful mycotoxins that cause human and animal health concerns. Aflatoxin M1 (AFM1) is the primary hydroxylated metabolite of aflatoxin B1 and is linked to the development of hepatocellular carcinoma and immunotoxicity in humans and animals. Because of the important role of dairy products in human life, especially children, AFM1 is such a major concern to humans because of its frequent occurrence in dairy products at concentrations high enough to cause adverse effects to human and animal health. Reduced its bioavailability becomes a high priority in order to protect human and animal health. Objectives This study aimed to investigate, in vivo, the ability of lactic acid bacteria (lactobacillus rhamnosus GAF01, LR) and clay mineral (bentonite, BT) mixture to mitigate/reduce AFM1-induced immunotoxicity, hepatotoxicity, nephrotoxicity and oxidative stress in exposed Balb/c mice. Materials and methods The in vivo study was conducted using male Balb/c mice that treated, orally, by AFM1 alone or in combination with LR and/or BT, daily for 10 days as follows: group 1 control received 200 µl of PBS, group 2 treated with LR alone (2.108 CFU/mL), group 3 treated with BT alone (1 g/kg bw), group 4 treated with AFM1 alone (100 μg/kg), group 5 co-treated with LR + AFM1, group 6 co-treated with BT + AFM1, group 7 co-treated with BT + LR + AFM1. Forty-eight h after the end of the treatment, the mice were sacrificed and the blood, spleen, thymus, liver and kidney were collected. The blood was used for biochemical and immunological study. Spleen and thymus samples were used to thymocytes and splenocytes assessments. Liver and kidney samples were the target for evaluation of oxidative stress enzymes status and for histological assays. Results The results showed that AFM1 caused toxicities in male Blab/c mice at different levels. Treatment with AFM1 resulted in severe stress of liver and kidney organs indicated by a significant change in the biochemical and immunological parameters, histopathology as well as a disorder in the profile of oxidative stress enzymes levels. Also, it was demonstrated that AFM1 caused toxicities in thymus and spleen organs. The co-treatment with LR and/or BT significantly improved the hepatic and renal tissues, regulated antioxidant enzyme activities, spleen and thymus viability and biochemical and immunological parameters. LR and BT alone showed to be safe during the treatment. Conclusion In summary, the LR and/or BT was able to reduce the biochemical, histopathological and immunological damages induced by AFM1 and indeed it could be exploited as one of the biological strategies for food and feedstuffs detoxification.

Invitro and Invivo Analysis of Human Milk Lactic Acid Bacteria Isolates for Their Anti-hypercholesterolemia Actions.

The aim of this study was to evaluate the cholesterol lowering ability of Lactic Acid Bacteria (LAB) isolated from human breast milk under in vitro and in vivo conditions. Six LAB isolates namely Lacticaseibacillus casei 1A, Lactobacillus gasseri 5A, Enterococcus faecium 2C, Limosilactobacillus fermentum 3D, Pediococcus acidilactici 1C, and Lactiplantibacillus plantarum 7A, were examined for their bile resistance, bile salt hydrolase activity, cholesterol assimilation and viability in cholesterol rich; DeMan Rogosa and Sharpe broth, simulated gastric, small and upper intestinal conditions. During in vivo experiments, two putative LAB isolates were orally gavage to BALB/c mice, fed with normal basal and cholesterol rich (HCD) diets, daily for a period of 4 weeks. Blood serum analysis including total serum cholesterol, triglycerides, high-density and low-density lipoprotein (LDL) cholesterol levels and total fecal LAB counts of the animals were determined. The isolates in study showed bile resistance and bile salt hydrolysis activity, while significant differences (P < 0.05) were seen in their cholesterol assimilation ability. L. gasseri 5A (195.67%) and L. plantarum 7A (193.78%) displayed highest cholesterol removal percentages, respectively. Animals in HCD, fed with L. gasseri 5A and L. plantarum 7A showed decreased levels of total cholesterol and LDL, compared to the control groups. In HCD group liver weight was increased, while fecal LAB counts were decreased. No changes were observed in behavior or body weight in all experimental groups. In conclusion, L. gasseri 5A and L. plantarum 7A isolated from human breast milk demonstrates significant hypocholesterolaemic actions in vitro and in vivo and might be considered a promising candidates for preventing hypercholesterolemia in man and animals.

Characterization of Lactic Acid Bacteria Isolated From Rotting Oranges and Use of Agropastoral Processing By-products as Carbon and Nitrogen Sources Alternative for Lactic Acid Production.

This study investigated the ability of lactic acid bacteria (LAB) isolated from oranges to use fish by-products (FB) and chicken by-products (CB) as nitrogen sources alternative to yeast extract for lactic acid (LA) production in a papaya by-product medium as a carbon source. Once the fermentation agents had been isolated, they were subjected to biochemical and molecular characterization. Inexpensive nitrogen sources, precisely CB and FB, were prepared, freeze-dried, and yield evaluated. Also, before to the fermentation experiments, the Total Kjehdahl Nitrogen (TKN) of these by-products and that of the yeast extract were determined. Then, three production media differing in terms of nitrogen source were formulated from these nitrogen sources. From the 22 LAB isolated from orange, two isolates of interest (NGO25 and NGO23) were obtained; all belonging to the Lactiplantibacillus plantarum species based on 16S rRNA gene sequencing. Furthermore, the production yield powder obtained after lyophilization of 1 L of CB and FB surpernatant were, respectively, 16.6 g and 12.933 g. The TKN of different nitrogen sources powder were 71.4 ± 0.000% DM (FB), 86.145 ± 0.001% DM (CB), and 87.5 ± 0.99% DM (yeast extract). The best kinetic parameters of LA production (LA (g/L): 31.945 ± 0.078; volumetric productivity (g/L.h): 1.331 ± 0.003; LA yield (mg/g) 63.89 ± 0.156; biomass (g/L) 7.925 ± 0.035; cell growth rate (g/L.h): 0.330 ± 0.001) were recorded by Lactiplantibacillus plantarum NGO25 after 24 h of fermentation. The latter data were obtained in the production medium containing CB as nitrogen sources. In addition, this production medium cost only $0.152 to formulate, compared to yeast extract which required $1.692 to formulate. Thus, freeze-dried CB can be used as an alternative to yeast extract in large-scale production of LA.

THE ABILITY OF Lactiplantibacillus plantarum TSD-10 AND DR-162 TO REDUCE AFLATOXIN AND MICROBIAL CONTAMINATION OF CORN

Feed safety becoming the main factor to produce good quality food. The purpose of this study was to evaluate the ability of lactic acid bacteria in degrading aflatoxin B1, suppressing the growth of contaminant bacteria, and its application on feed. Biological degradation of aflatoxin B1 (AFB1) in liquid cultures and Escherichia coli and Saccharomyces aureus inhibition by Lactobacillus plantarum were examined. Fermentation of corn for 24 hours by L. plantarum was used to determine the ability of LAB to decrease E. coli, coliform, mold, and AFB1 on a solid substrate. This study showed that both L. plantarum TSD-10 and DR-162 could inhibit E. coli growth at 3% and 5% supernatant addition. The addition of 5% L. plantarum DR-162 and TSD-10 could inhibit S. aureus at 97.40% and 97.28%, respectively. Furthermore, viable cells of L. plantarum DR-162 and TSD-10 removed 56.97% and 64.65% AFB1 within 72 h of incubation, respectively. The AFB1 reduction by nonviable cell was lower than the viable cell. The population of E. coli, coliform, and mold completely disappeared in both fermentation treatment of corn by L. plantarum DR-162 and TSD-10 at 3% and 5%. AFB1 significantly decreased by 17.57% and 22.60% on 5% L. plantarum DR-162 and TSD-10 treatment.

Screening lactic acid bacteria and yeast strains for soybean paste fermentation in northeast of China.

Soybean paste was a traditional fermented product in northeast China, mainly fermented by molds, yeast, Bacillus, and lactic acid bacteria. In this study, the safety and fermentation ability of lactic acid bacteria and yeast strains isolated from traditional soybean paste in northeast China were evaluated, and the dynamic changes of biogenic amines, aflatoxin, total acids, amino acid nitrogen, and volatile compounds were investigated during the fermentation of the traditional soybean paste. Among the tested strains, Lactiplantibacillus plantarum DPUL-J8 could decompose putrescine by 100%, and no biogenic amine was produced by Pichia kudriavzevii DPUY-J8. Lactiplantibacillus plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 with strong biogenic amine degrading capacities were inoculated into the soybean paste. After 30 days of fermentation, the content of biogenic amines and aflatoxin in the fermented soybean paste declined by more than 60% and 50%, respectively. At the same time, compared with the control group without inoculation, the contents of total acid (1.29 ± 0.05 g/100 g), amino acid nitrogen (0.82 ± 0.01 g/100 g), and volatile compounds in soybean paste fermented by L. plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 were significantly increased, which had a good flavor. These results indicated that the use of L. plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 as starter cultures for soybean paste might be a good strategy to improve the safety and flavor of traditional Chinese soybean paste.

Exploring the Cholesterol-Modifying Abilities of Lactobacilli Cells in Digestive Models and Dairy Products.

This study aimed to investigate the ability of lactic acid bacteria to remove cholesterol in simulated gastric and intestinal fluids. The findings showed that the amount of cholesterol removed was dependent on the biomass, viability, and bacterial strain. Some cholesterol binding was stable and not released during gastrointestinal transit. The presence of cholesterol affected the fatty acid profile of bacterial cells, potentially influencing their metabolism and functioning. However, adding cholesterol did not significantly impact the survival of lactic acid bacteria during gastrointestinal transit. Storage time, passage, and bacterial culture type did not show significant effects on cholesterol content in fermented dairy products. Variations in cell survival were observed among lactic acid bacteria strains in simulated gastric and intestinal fluids, depending on the environment. Higher milk protein content was found to be more protective for bacterial cells during gastrointestinal transit than fat content. Future research should aim to better understand the impact of cholesterol on lactic acid bacteria metabolism and identify potential health benefits.

Genetic and phenotypic assessment of the antimicrobial activity of three potential probiotic lactobacilli against human enteropathogenic bacteria.

Lactobacilli are avid producers of antimicrobial compounds responsible for their adaptation and survival in microbe-rich matrices. The bactericidal or bacteriostatic ability of lactic acid bacteria (LAB) can be exploited for the identification of novel antimicrobial compounds to be incorporated in functional foodstuffs or pharmaceutical supplements. In this study, the antimicrobial and antibiofilm properties of Lactiplantibacillus pentosus L33, Lactiplantibacillus plantarum L125 and Lacticaseibacillus paracasei SP5, previously isolated form fermented products, were examined, against clinical isolates of Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Enteritidis and Escherichia coli. The ability of viable cells to inhibit pathogen colonization on HT-29 cell monolayers, as well as their co-aggregation capacity, were examined utilizing the competitive exclusion assay. The antimicrobial activity of cell-free culture supernatants (CFCS) was determined against planktonic cells and biofilms, using microbiological assays, confocal microscopy, and gene expression analysis of biofilm formation-related genes. Furthermore, in vitro analysis was supplemented with in silico prediction of bacteriocin clusters and of other loci involved in antimicrobial activity. The three lactobacilli were able to limit the viability of planktonic cells of S. aureus and E. coli in suspension. Greater inhibition of biofilm formation was recorded after co-incubation of S. enterica with the CFCS of Lc. paracasei SP5. Predictions based on sequence revealed the ability of strains to produce single or two-peptide Class II bacteriocins, presenting sequence and structural conservation with functional bacteriocins. The efficiency of the potentially probiotic bacteria to elicit antimicrobial effects presented a strain- and pathogen-specific pattern. Future studies, utilizing multi-omic approaches, will focus on the structural and functional characterization of molecules involved in the recorded phenotypes.

Supplementation of lactic acid bacteria has positive effects on the mucosal health of Atlantic salmon (Salmo salar) fed soybean meal

We investigated the ability of lactic acid bacteria, when added individually or in combination in feeds, to prevent soybean meal-induced enteritis in Atlantic salmon. A control diet, designed to induce enteritis, was formulated with marine ingredients and 20% soybean meal. Three more diets were produced by coating the control diet with two bacteria, either singly (Lactobacillus plantarum; L. fermentum) or in combination. The fish were fed the abovementioned diets for 38 days. We performed histological assessments and evaluated the expression of selected mucin and antimicrobial peptide genes in the dorsal skin, gills, and distal intestine. Digesta were also collected to study the short chain fatty acids. Feeding bacteria, individually or in combination, altered the short chain fatty acids−acetoacetic acid, lactic acid, succinic acid, propionic acid−and the total fatty acids in the digesta significantly. Of all the determined short chain fatty acids, the concentration of acetoacetic acid was the highest, and the fish fed the combination of the two bacteria had the significantly highest value. Succinic acid was also significantly higher in fish fed the combination compared to the control group and the L. fermentum group. Total fatty acids were significantly higher in fish fed the combination than those fed L. fermentum. Compared to the control and probiotic combination-fed fish, those fed L. plantarum had higher defensin1 expression in the skin. We also observed significantly higher number of gill mucous cells in the fish fed the blend compared to the control group. Lamina propria width was significantly reduced in fish fed the blend. Supra nuclear vacuoles were higher in fish fed the single species or the blend, compared to the control group. Thus, adding the probiotics to a soybean meal diet can elevate the digesta short chain fatty acids and intestine supranuclear vacuoles, and reduce the lamina propria width, which probably indicate prevention of enteritis.

CRISPR/Cas tools for enhancing the biopreservation ability of lactic acid bacteria in aquatic products.

Lactic acid bacteria (LAB) plays a crucial role in aquatic products biopreservation as it can inhibit many bacteria, in particular the specific spoilage organisms (SSOs) of aquatic products, by competing for nutrients or producing one or more metabolites which have antimicrobial activity, such as bacteriocins. Lactobacillus spp. and Lactococcus spp. are the most commonly used Lactic acid bacterias in aquatic products preservation. The improvement of gene editing tools is particularly important for developing new lactic acid bacteria strains with superior properties for aquatic products biopreservation. This review summarized the research progress of the most widely used CRISPR/Cas-based genome editing tools in Lactobacillus spp. and Lactococcus spp. The genome editing tools based on homologous recombination and base editor were described. Then, the research status of CRISPRi in transcriptional regulation was reviewed briefly. This review may provide a reference for the application of CRISPR/Cas-based genome editing tools to other lactic acid bacteria species.

Safety evaluation and application of lactic acid bacteria and yeast strains isolated from Sichuan broad bean paste.

Broad bean paste is one of the most popular characteristic traditional fermented bean products in China, which is prepared by mixed fermentation of a variety of microorganisms, among which lactic acid bacteria and yeast played an important role in the improvement of the fermented broad bean paste quality. However, the traditional open-air fermentation of broad bean paste brought some risks of harmful microorganisms. In this study, the safety and fermentation ability of lactic acid bacteria and yeast strains isolated from traditional broad bean paste was evaluated. The results showed that the protease activity of the strain Lactobacillus plantarum DPUL-J5 (366.73 ± 9.00 U/L) and Pichia kudriavzevii DPUY-J5 (237.18 ± 10.93 U/L) were the highest. Both strains produced little biogenic amines, and did not exhibit α-hemolytic activity or antibiotic resistance for some of the antibiotics most used in human medicine. Furthermore, the broad bean paste fermentation involving DPUL-J5 and DPUY-J5 was beneficial for accumulating higher total acid (1.69 ± 0.01 g/100 g), amino-acid nitrogen (0.85 ± 0.03 g/100 g), and more volatile flavor compounds, meanwhile, reducing the levels of biogenic amines and aflatoxin B1. Therefore, this study provided a new strategy to improve the safety and quality of traditional broad bean paste.

Probiotic Properties Including the Antioxidant and Hypoglycemic Ability of Lactic Acid Bacteria from Fermented Grains of Chinese Baijiu.

In this study, lactic acid bacteria (LAB) strains were isolated from fermented grains of traditional Chinese Baijiu, and their probiotic properties were characterized. Eleven out of 29 LAB strains showed good tolerance to the gastrointestinal tract and bile salts. The surface characteristics (auto-aggregation, co-aggregation, hydrophobicity), safety (hemolytic and antibiotic sensitivity), antibacterial activity against three foodborne pathogens, and antioxidant and hypoglycemic properties of the 11 LAB strains were investigated. Principal component analysis (PCA) was used to comprehensively evaluate LAB strains and their probiotic properties. It was found that Weissella cibaria (OP288150), Pediococcus acidilactici (OP288151), Pediococcus pentosaceus (OP288154), Pediococcus pentosaceus (OP288156) and Levilactobacillus brevis (OP288158) showed high probiotic properties, with potential for commercial development. The results also demonstrated that fermented grains of Chinese Baijiu can be used as a source of high-quality probiotics.

Administration of the probiotic Lactiplantibacillus paraplantarum is effective in controlling hyperphosphatemia in 5/6 nephrectomy rat model

AimsSeveral studies have linked gut microbes to human diseases. Most of the mechanisms by which lactic acid bacteria have beneficial effects on the human body are related to immune modulation. Controlled studies of the ability of lactic acid bacteria to absorb phosphorus directly from the intestine and thereby control serum phosphorus level in in vivo uremic animal models are limited. Materials and methodsWe screened lactic acid bacteria living in Korean fermented foods to identify those that absorb the most phosphorus and noted Lactiplantibacillus paraplantarum KCCM 11826P. The mechanism through which better intracellular absorption of phosphorus occurs in this strain was studied using genomic DNA sequencing. After the strain was administered to 5/6 nephrectomized rats for 6 weeks, it was observed whether hyperphosphatemia had improved. Key findingsThe L. paraplantarum KCCM 11826P strain has a polyP gene cluster; thus, it absorbs phosphorus better than other bacteria and can suppress strains that produce indole. Supplementing the diets of 5/6 nephrectomized rats with this L. paraplantarum strain significantly decreased serum phosphate level (by 22 %) and reduced blood indoxyl sulphate concentration (by 40 %) compared with vehicle treatment. SignificanceThese results suggest that Lactiplantibacillus preparations can be used for multiple purposes, such as the removal of phosphorus and uremic toxins from patients with chronic kidney disease (CKD). This study also demonstrates the novel concept of a probiotic phosphate binder.

Capabilities of bio-binding, antioxidant and intestinal environmental repair jointly determine the ability of lactic acid bacteria to mitigate perfluorooctane sulfonate toxicity.

Perfluorooctane sulfonate (PFOS) is a novel environmental contaminant that can be enriched in humans through the food chain, causing liver diseases, neurotoxicity and metabolic disorders. Lactic acid bacteria (LAB) are safe food-grade microorganisms that exhibit high antioxidant activity and bio-binding capacity towards toxins. Here, strains of LAB with different PFOS binding capacities and antioxidant activities were selected and analyzed for their ability in mitigating the toxic effects of PFOS. The results showed that the PFOS binding capacity and antioxidant activity of LAB largely influenced their ability in alleviating the toxic effects of PFOS. Notably, the individual LAB strains with low PFOS binding capacities and antioxidant activities also attenuated the toxic effects of PFOS, which was shown to up-regulate the contents of short-chain fatty acids (SCFAs) in the cecum and of tight junction proteins in the intestines of mice. Therefore, the mitigation pathway of PFOS-induced toxic damage by LAB is not limited to bio-binding and antioxidant. Repairing the gut environment damaged by PFOS is also essential for LAB to alleviate the toxic damage due to PFOS and may be partly independent of the bio-binding and antioxidant. Therefore, LAB as an alternative pathway for alleviating PFOS toxicity is suggested.