Lactic Acid Bacteria Research Articles

Growth dynamics, antagonistic activity and acid production of Lactiplantibacillus (=Lactobacillus) plantarum KT-L18/1 and Bacillus subtilis BPT-B1 inoculants in alfalfa silage

Aim. To study growth dynamics, antagonistic activity and acid formation of two inoculant strains, Lactiplantibacillus (=Lactobacillus) plantarum КТ-L18/1 and Ваcillus subtilis ВРТ-В1, that were introduced into alfalfa silage, up to 30 days of fermentation. Methods. A streptomycin-resistant strain of both above-mentioned organisms, obtained in earlier research, was used to achieve the research aims. Alfalfa was artificially wilted and dried to a dry matter content of 39–40 %. Fermentation was conducted under anaerobic conditions in polyethylene bags. Inoculant was added at a concentration of 108 CFU/kg alfalfa. The resulting 12 × 3 = 36 bags were kept at room temperature in a dark place for 30 days. At each examination date one sample per treatment was used and examined after cultivation of the two inoculants on elective De Man-Rogosa-Sharpe (MRS) agar and meat infusion agar (MIA), containing streptomycin. The antibacterial (ABA) and antifungal activities (AFA) were studied by the agar diffusion method. Results. After 30 days of ensiling the alfalfa samples, L. plantarum КТ-L18/1str and В. subtilis ВРТ-В1str were still present at levels of 9.2 lg CFU/g and 6.9 lg CFU/g respectively. In the natural population of LAB, L. plantarum КТ-L18/1str had a dominant position. After 30 days of the alfalfa fermentation L. plantarum КТ-L18/1str and В. subtilis ВРТ-В1str maintained ABA and AFA to the PPB strains (S. aureus, P. aeruginosa, S. typhimurium) and fungal strains tested. However, the antagonistic activities of the two inoculant strains decreased during the fermentation, for L. plantarum КТ-L18/1str from 7–21 %, and for В. subtilis ВРТ-В1str from 16–21 %. Compared to the uninoculated control treatment, the inoculated silage treatments had a lower pH level (5.2–5.3), an increased number of lactic acid bacteria (LAB) (by 32 %), and clostridia were no longer detected. The inoculation impacted fungi down to a level of 102–103 CFU/g that can ensure the aerobic stability of the feed. Conclusions. The inoculant strains and L. plantarum КТ-L18/1str and Ваcillus subtilis ВРТ-В1str showed a high competitiveness with background microbiota in an ensiling experiment with alfalfa. The antagonistic activity of the two strains to PPB after fermentation was preserved at a high level, albeit with a decrease of 7–21 %. Ваcillus subtilis ВРТ-В1str kept its AFA against all three fungal strains tested during the 30 days of fermentation. For L. plantarum КТ-L18/1str this was true for a strain of the Penicillium chrysogenum only. The inoculation of and L. plantarum КТ-L18/1str and Ваcillus subtilis ВРТ-В1str caused a decrease in pH of 8–9 % at the end of the fermentation period, an accumulation of LAB with 32 %, and the inhibition of the growth of clostridia up to undetectability in the fermented alfalfa. For both inoculants, compared to uninoculated control variant, fungi decreased down to 102–103 CFU/g of the feed, which can ensure the aerobic stability of the feed.

Phyllospheric bacterial communities in spinach are influenced by soil nitrogen availability

Nitrogen is an essential macronutrient for the growth and development of plants. As with most crops, nitrogen-based fertilizers are used to improve productivity and quality of spinach. Although the significance of the soil microbiome in the inorganic nitrogen cycle is recognized, soil nitrogen's impact on phyllosphere bacterial communities remains unclear. This study investigates changes in the bacterial community composition and diversity residing on spinach leaves cultivated in soils with varying nitrogen levels. Sixty-eight spinach samples were processed using culture-dependent and independent methods to evaluate phyllosphere-associated bacterial communities. In culture-dependent methods, populations of Mesophiles (MS), Psychrotrophs (PY), coliforms (CL), and lactic acid bacteria (LAB) were quantified by plate counts using appropriate culture media. In culture-independent methods, bacteria were determined by amplicon sequencing based on the V3-V4 region of the bacterial 16S rRNA gene. Counts of MS, PY, CL, and LAB on low-nitrogen soil-grown spinach were 7.4, 7.1, 6.9, and 5.5 log CFU/g, respectively, while high-nitrogen soil-grown spinach showed counts of 7.5, 7.0, 7.0, and 5.7 log CFU/g. These counts did not differ significantly between the nitrogen levels used for spinach cultivation (p > 0.05). Amplicon sequencing, however, revealed differences in relative abundance between different taxa levels and soil nitrogen levels. The relative abundance of Erwinaceae and Planococcaceae was higher in high-nitrogen soil-grown spinach. The relative abundance of Pseudomonadaceae, Enterobacteriaceae, and Rhizobiaceae was higher in low-nitrogen soil-grown spinach. Soil nitrogen content significantly affected spinach phyllosphere microbiome beta-diversity. Our results suggest that bacterial communities of spinach phyllosphere are influenced by soil nitrogen content.

Addition of polyphenolic extracts of Myrtus communis and Arbutus unedo fruits to whey: valorization of a common dairy waste product as a functional food.

Whey, a nutrient-rich byproduct of the dairy sector, possesses high potential for creating novel nutraceutical products. The present study investigates a potential new functional food by incorporating polyphenolic extracts from Myrtus communis and Arbutus unedo fruits into whey in both liquid (LA) and powder (PA) addition forms. Chemical, microbiological, physical stability and antioxidant activity were monitored for 60 days (from T0 to T60). Both LA and PA of fruit extracts remained chemically stable for the whole period, except for A. unedo PA, which showed a decline in polyphenols after T45. Enriched whey samples showed higher antioxidant activity than pure whey. Microbiological analysis revealed the presence of lactic acid bacteria, indicating potential prebiotic effects. However, the high tannin concentration of A. unedo extracts partially modified the casein micelle structure. Whey enriched with Mediterranean fruit extracts shows great potential as a functional food, combining the benefits of plant antioxidants, probiotic bacteria and good stability. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of kefir grain concentration on rheological, microbiological, and physicochemical characteristics of bovine colostrum kefir

Bovine colostrum has high nutrition content such as protein, fat, peptide, micro-nutrients, antimicrobial components and bioactive compounds that benefit the body. Kefir is one way of diversifying food products as fermented beverage products to increase the utilization and functional properties of bovine colostrum, which has a unique taste. Production of colostrum kefir requires the right concentration of kefir grains to obtain high-quality characteristics. Evaluating the effect of kefir grain concentration on the rheological, microbiological, and physicochemical characteristics of bovine colostrum kefir was the purpose of this research. This study used one factorial design with the variation of kefir grain concentrations 10% (T1), 20% (T2), and 30% (T3) (w/v) with seven replications. Rheological analysis was conducted, followed by total lactic acid bacteria, yeast, microbes, protein, fat, ash, water content, carbohydrate, pH, total dissolved solids and alcohol content. Based on the result, different kefir grain concentrations significantly decreased total LAB, yeast, microbes, protein, ash, pH, and total dissolved solids but increased carbohydrate and water content with the addition of kefir grain concentration. Rheology behavior, fats, and alcohol content had no significant difference. Treatment of 10% of kefir grain concentration is the most suitable as it contains the highest total LAB and yeast.

Lactobacillus johnsonii JERA01 upregulates the production of Th1 cytokines and modulates dendritic cells-mediated immune response.

Lactic acid bacteria are known to have various effects on the immune system. The type and extent of the effect differ, depending on the type of lactic acid bacteria. This study aimed to investigate the effects of Lactobacillus johnsonii bacterin on mouse-derived immune cells. Treating splenocytes with L. johnsonii bacterin slightly increased the metabolic activity. Additionally, the expression of the activation marker CD25 and production of the Th1-type inflammatory cytokine interferon (IFN)- gamma increased. We confirmed that the increase in IFN-gamma production due to L. johnsonii stimulation was mainly due to T and B cells among splenocytes. Treating dendritic cells (DCs) with L. johnsonii bacterin at concentrations of 106 and 107 cfu/ ml significantly increased tumor necrosis factor-alpha, a pro-inflammatory cytokine, and interleukin-12, a cell-mediated immunity cytokine. Additionally, the expression of surface markers increased. Allogeneic mixed lymphocyte reactions showed that L. johnsonii reduced the antigen-presenting ability of DCs. In cocultures of DCs and splenocytes, L. johnsonii decreased cellular metabolic activity and increased cell death. L. johnsonii upregulated the expression of programmed death ligand 1 on DCs. The findings of this study indicate that L. johnsonii bacterin has immunomodulatory and immunostimulatory effects. While L. johnsonii increased the expression of cytokines and surface markers of immune cells, it modulated DC-mediated immune response. Further studies are needed to determine the effects of L. johnsonii bacterin on DCs and related immune cells.

Harnessing Oxidative Stress to Obtain Natural Riboflavin Secreting Lactic Acid Bacteria for Use in Biofortification.

Lactococcus lactis suffers from oxidative stress and riboflavin starvation at elevated temperatures due to dissolved oxygen, which can be relieved partially by exogenously supplied riboflavin. Here we explore whether this phenomenon can be harnessed to obtain riboflavin overproducing mutants. Using a riboflavin auxotrophic L. lactis strain as a riboflavin biosensor, we screened L. lactis cultures that had been exposed to temperature induced oxidative stress for up to one year. Riboflavin secreting mutants could readily be identified, some of which had arisen after just two weeks of exposure to oxidative stress. Whole genome sequencing revealed mutations in the riboswitch, which regulate riboflavin biosynthesis. Riboflavin secretion conferred a significant increase in tolerance to oxidative stress and enabled growth at high temperatures in the presence of dissolved oxygen. It was subsequently demonstrated that vigorous aeration at high temperature (37 °C) could prompt rapid emergence of riboflavin secreting mutants. The protective effect provided by riboflavin against oxidative stress may explain the natural occurrence of lactic acid bacteria (LAB) secreting riboflavin. By optimizing fermentation conditions and eliminating lactate formation, we achieved 64 mg/L riboflavin, the highest reported titer so far for LAB, which indicates great potential for use as a riboflavin fortification agent in food.

Effects of Fermented Kimchi Consumption on Anthropometric and Blood Cardiometabolic Indicators: A Systematic Review and Meta-Analysis of Intervention Studies and Prospective Cohort Studies.

Increasing global kimchi consumption has prompted interest in its health impact. However, comprehensive reviews of the influence of kimchi on cardiometabolic risk factors, especially meta-analyses, remain limited. This review assessed the impact of fermented kimchi consumption on cardiometabolic risk factors by systematically reviewing human intervention and prospective cohort studies, and conducting a meta-analysis of intervention studies. A literature search of PubMed, EMBASE, Scopus, Web of Science, RISS, KISS, and ScienceON databases was conducted through April 30, 2024. The inclusion criteria encompassed studies that examined the effects of fermented kimchi, without any added ingredients or lactic acid bacteria, on health outcomes, including anthropometric measures, blood pressure, cardiometabolic and glycemic indicators, inflammatory cytokines, and the incidence of related chronic diseases. Data extraction and quality evaluation were conducted independently by 3 researchers. Pooled effect sizes were calculated as weighted mean differences (WMDs) with 95% CIs employing random-effects models. Five intervention studies (205 participants) and 4 prospective cohort studies (42 455 participants) were selected. A meta-analysis of the intervention studies revealed a significant reduction in fasting blood glucose (WMD: -1.93 mg/dL; 95% CI: -3.82, -0.03; I2 = 17.4%) following the consumption of fermented kimchi. After excluding studies that contributed to increased heterogeneity, significant inverse associations were observed between fermented kimchi consumption and triglycerides (WMD: -28.9 mg/dL; 95% CI: -53.2, -4.5; I2 = 0.0%), systolic blood pressure (WMD: -3.48 mmHg; 95% CI: -5.95, -1.01, I2 = 0.0%), and diastolic blood pressure (WMD: -2.68 mmHg; 95% CI: -4.75, -0.62; I2 = 0.0%). Prospective cohort studies linked higher kimchi intake with a lower incidence of cancer and metabolic syndrome and an increased likelihood of achieving normal body weight. This review supports beneficial effects of fermented kimchi on cardiometabolic health. However, due to the limited number of studies, these findings should be interpreted cautiously, highlighting the need for further research in diverse populations. PROSPERO registration No. CRD42024532020.

Characteristics and in vitro properties of potential probiotic strain Fructobacillus tropaeoli KKP 3032 isolated from orange juice.

Fructobacillus, a Gram-positive, non-spore-forming, facultative anaerobic bacterium, belongs to the fructophilic lactic acid bacteria (FLAB) group. The group's name originates from fructose, the favored carbon source for its members. Fructobacillus spp. are noteworthy for their distinctive traits, captivating the interest of scientists. However, there have been relatively few publications regarding the isolation and potential utilization of these microorganisms in the industry. In recent years, F. tropaeoli has garnered interest for its promising role in the food and pharmaceutical sectors, although the availability of isolates is rather limited. A more comprehensive understanding of Fructobacillus is imperative to evaluate their functionality in the industry, given their unique and exceptional properties. Our in vitro study on Fructobacillus tropaeoli KKP 3032 confirmed its fructophilic nature and high osmotolerance. This strain thrives in a 30% sugar concentration, shows resistance to low pH and bile salts, and exhibits robust autoaggregation. Additionally, it displays significant antimicrobial activity against foodborne pathogens. Evaluating its probiotic potential, it aligns with EFSA recommendations in antibiotic resistance, except for kanamycin, to which it is resistant. Further research is necessary, but preliminary analyses confirm the high probiotic potential of F. tropaeoli KKP 3032 and its ability to thrive in the presence of high concentrations of fructose. The results indicate that the isolate F. tropaeoli KKP 3032 could potentially be used in the future as a fructophilic probiotic, protective culture, and/or active ingredient in fructose-rich food.

Presence of lactic acid bacteria in hydrogen production by dark fermentation: competition or synergy.

Dark fermentation in mixed cultures has been extensively studied due to its great potential for sustainable hydrogen production from organic wastes. However, microbial composition, substrate competition, and inhibition by fermentation products can affect hydrogen yield and production rates. Lactic acid bacteria have been identified as the key organisms in this process. On one hand, lactic acid bacteria can efficiently compete for carbohydrate rich substrates, producing lactic acid and secreting bacteriocins that inhibit the growth of hydrogen-producing bacteria, thereby decreasing hydrogen production. On the other hand, due to their metabolic capacity and synergistic interactions with certain hydrogen-producing bacteria, they contribute positively in several ways, for example by providing lactic acid as a substrate for hydrogen generation. Analyzing different perspectives about the role of lactic acid bacteria in hydrogen production by dark fermentation, a literature review was done on this topic. This review article shows a comprehensive view to understand better the role of these bacteria and their influence on the process efficiency, either as competitors or as contributors to hydrogen production by dark fermentation.

Impact of Exopolysaccharides from Fructilactobacillus sanfranciscensis Ls5 on the Quality of Mantou: A Comparative Study of Fermentation Conditions

Lactic acid bacteria (LAB) and their exopolysaccharides (EPS) have the potential to enhance the quality of flour-based products. This study investigated the effect of EPS produced by Fructilactobacillus sanfranciscensis Ls5 on the quality of Mantou. LAB strains with high EPS production were isolated from traditional fermenters, and their characteristics and EPS properties were examined. Four different fermentation conditions (Blank, Yeast, Ls5-Yeast, and EPS-Yeast) were compared in terms of their effects on the physicochemical properties, in vitro digestion characteristics, and shelf-life of Mantou. The incorporation of Ls5 and its EPS into Mantou resulted in a lower dough fermentation pH, increased organic acid production, and enhanced fermentation activity. Additionally, the incorporation of Ls5 and its EPS led to significant improvements in the quality of the Mantou, including the extension of shelf-life, improved sensory evaluation, and a reduction in the sugar content. Additionally, there was an increase in resistant starch content during digestion in both types of Mantou, which could offer potential benefits to human glycemic health.

Calcium Transport and Enrichment in Microorganisms: A Review

Calcium is a vital trace element for the human body, and its deficiency can result in a range of pathological conditions, including rickets and osteoporosis. Despite the numerous types of calcium supplements currently available on the market, these products are afflicted with a number of inherent deficiencies, such as low calcium content, poor aqueous solubility, and low human absorption rate. Many microorganisms, particularly beneficial microorganisms, including edible fungi, lactic acid bacteria, and yeast, are capable of absorbing and enriching calcium, a phenomenon that has been widely documented. This opens the door to the potential utilization of microorganisms as novel calcium enrichment carriers. However, the investigation of calcium-rich foods from microorganisms still faces many obstacles, including a poor understanding of calcium metabolic pathways in microorganisms, a relatively low calcium enrichment rate, and the slow growth of strains. Therefore, in order to promote the development of calcium-rich products from microorganisms, this paper provides an overview of the impacts of calcium addition on strain growth, calcium enrichment rate, antioxidant system, and secondary metabolite production. Additionally, it highlights calcium transport and enrichment mechanisms in microorganism cells and offers a detailed account of the progress made on calcium-binding proteins, calcium transport pathways, and calcium storage and release. This paper offers insights for further research on the relevant calcium enrichment in microorganism cells.

Lactic Acid Production from Distiller’s Dried Grains Dilute Acid Hydrolysates

Lactic acid (LA) is an important chemical with diverse applications in various industries. LA can be produced by the fermentation of different substrates by many microorganisms such as bacteria, fungi, yeasts, and algae. Lactic acid bacteria (LAB) are generally accepted as the main producers of LA. A distinct characteristic of LAB is the complexity of the fermentation media. Distiller’s dried grains with solubles (DDGS), a by-product from bioethanol production, represent a promising substitute for costly sugars in the nutrition media for LA production. In the present paper, the possibility of using dilute acid DDGS hydrolysates as a substrate for LA fermentation was investigated. The influence of different factors (acid concentration, time, pressure, solid-to-liquid ratio) on the reducing sugars (RS) obtained was studied. Additional enzyme hydrolysis was carried out to increase RS content in the hydrolysates. LA production from hydrolysates without and with control of the pH during fermentation was monitored and compared with lactose as a substrate. Inhibition of the process was observed in both substrates in the absence of pH control which was overcome in the case of pH control. A mathematical model based on the Verhulst and Ludeking–Piret equations was proposed and tested, showing very good agreement with experimental data.

Характеристика генома двух новых фагов Lactococcus lactis phage vL_296 и vL_20A

Fermented dairy products are produced using starter cultures. They ferment milk to create products with a certain texture, aroma, and taste. However, the lactic acid bacteria used in this production are prone to bacteriophage infection. We examined the genomes of two newly discovered bacteriophage species that were isolated from cheese whey during the cheesemaking process. We have determined the species and the lytic spectrum of these bacteriophages. Phages vL_20A and vL_296 were isolated using lactococcal indicator cultures. They have unique lytic spectra: of the 21 possible identified host bacteria, only four are shared amongst them. The vL_20A and vL_296 genomes comprise linear double-stranded DNA lengths with 21,909 and 22,667 nucleotide pairs, respectively. Lactococcus phage bIL67 (ANI 93.3 and 92.6, respectively) is the closest to the phages vL_20A and vL_296. The analysis of the CRISPR spacers in the genomes of starter cultures did not reveal any phage-specific vL_20A or vL_296 among them. This study highlights the biodiversity of L. lactis phages, their widespread presence in dairy products, and their virulence. However, the virulence of phages is balanced by the presence of a significant number of bacterial strains with different sensitivities to phages in the starter cultures due to the bacterial immune system.

Effect of nanoemulsified and encapsulated Planiliza abu protein on fortified yogurt

AbstractFortified dairy products such as yogurt have attracted a lot of attention due to the increasing concern for public health. This study aimed to determine the effects of nanoemulsified and a microencapsulated protein hydrolysate obtained from Planiliza abu on some of the properties of yogurt. The physicochemical, rheological, microbiological, and sensory evaluation of the fortified yogurt samples stored at 4°C were assessed during 21 days. The fish protein hydrolysates (FPHs) < or >10 kDa protein were used. The amino acid profile of Planiliza abu was glutamic acid (78.99%), aspartic acid (59.53%), and lysine (53.54%). No significant change was observed in titratable acidity (TA) and pH of supplemented yogurts during refrigeration. The highest survival level of lactic acid bacteria (LAB), water‐holding capacity (WHC), and viscosity and the lowest syneresis were observed in fortified samples with FPH <10 kDa. The highest ferric reducing antioxidant power (FRAP) was achieved in yogurt fortified with nanoemulsion FPH < 10 kDa (NEh10a, 0.41 mg/g). The results showed that fortified yogurt with FPH, particularly less than 10 kDa, is among the desirable functional food with appropriate gel network and consistency as well as better taste and mouth feel, and higher overall acceptance.

Lactobacillus plantarum KAD protects against high-fat diet-induced hepatic complications in Swiss albino mice: Role of inflammation and gut integrity.

Hepatic complications are the major health issues associated with dietary intake of calorie saturated food e.g. high-fat diet (HFD). Recent studies have revealed the beneficial effects of probiotics in HFD fed mice with hepatic complications. Some probiotic Lactic acid bacteria (LAB) e.g. Lactobacillus plantarum have drawn our attention in managing hepatic complications. Here, we aim to elucidate the protective effects of L. plantarum KAD strain, isolated from ethnic fermented food 'Kinema' in HFD-fed mice as, a preventive approach. Eighteen Swiss albino mice were equally divided into 3 groups: Normal Diet (ND), negative control (HFD), and HFD-fed with oral L. plantarum KAD supplementation (LP). All the experimental groups were subjected to specific diet according to grouping for eight weeks. After completion of the regime, subjects were anesthetized and sacrificed. Organs, blood, and fecal samples were collected and stored appropriately. Physical indices, including body weight gain, organ co-efficients were calculated along with assessment of glycemic, lipidomic, hepatic, oxidative stress, inflammatory, and histological parameters. Gut microbiota analysis was performed using 16s V3-V4 fecal metagenomic profiling, and sequencing were done using Illumina Miseq system. Oral administration of L. plantarum KAD is found to significantly (p<0.05) restore metabolic health by normalizing glycemic, lipidomic, hepatic parameters, oxidative stress and inflammatory parameters. Moreover, LP group (7.08±0.52 mg/g) showed significantly (p<0.001) decreased hepatic triglyceride level compared to HFD group (20.07±1.32 mg/g). L. plantarum KAD improved the adipocytic, and colonic histomorphology with significantly better scoring pattern. LP group (1.83±0.41) showed a significantly (p<0.001) reduced hepatic score compared to negative control group (5.00±0.63), showing reduced hepatosteatosis, and immune infiltration. The strain modulated gut health by altering its microbial composition positively towards normalization. In conclusion, the results of the experiment suggest that prophylactic L. plantarum KAD administration has beneficial effects on the onset of HFD induced hepatic complications in mice. Further studies are needed, on this strain for its clinical use as dietary supplement.

Impact of low FODMAP sourdough bread on gut microbiota using an in vitro colonic fermentation model

This study explores the development of whole-grain sourdough bread with reduced FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) content to offer dietary solutions for individuals with irritable bowel syndrome (IBS). Three sourdough breads were prepared using different lactic acid bacteria (LAB) strains including Lactiplantibacillus plantarum FST1.7 (SD-FST1.7), Lacticaseibacillus paracasei R3 (SD-R3), and Pediococcus pentosaceus RYE106 (SD-RYE106). A control sourdough bread was prepared using baker’s yeast (SD-control). In vitro digestion and in vitro colonic fermentation were employed on bread samples with cellulose (negative control) and inulin (positive control), followed by 16S rRNA sequencing and short-chain fatty acid (SCFA) analysis to evaluate the impact on gut microbiota and SCFA levels. Alpha and beta diversity did not reveal any significant differences within the groups following in vitro colonic fermentation (FDR &amp;gt; 0.05). Taxonomic analysis displayed Firmicutes as the predominant phylum across all fecal samples at the end of colonic fermentation. Actinobacteriota was significantly lower in cellulose fermented fecal samples compared to samples fermented with SD-Control (ANCOMBC, FDR = 0.02) and inulin (ANCOMBC, FDR = 0.0001). Fecal samples fermented with inulin had significantly higher Bacteroidota levels compared to those fermented with cellulose (ANCOMBC, FDR =0.002). Acetate levels were higher in fecal samples fermented with SD-FST1.7 compared to those fermented with SD-R3 and SD-RYE106 (p = 0.03 for both). Positive correlations between butyrate and Lachnospira, Agathobacter, and Bifidobacterium were observed, demonstrating the potential of sourdough fermentation to influence gut health and support IBS management.

Synergistic Antibacterial Effect of Lactic Acid Bacteria and Baicalin Against Staphylococcus aureus In Vitro and In Vivo.

Pathogenic bacteria such as Staphylococcus aureus (S. aureus) are the principal cause of cow mastitis, which primarily impacts milk yield and results in significant financial losses for the animal husbandry industry. Lactic acid bacteria-cell-free supernatant (LAB-CFS) and baicalin (BAI) both have a number of biological effects, including decreasing inflammation. The combined use of LAB-CFS and BAI does not appear to have been used toprotective against mastitis, however, and the underlying mechanisms are yet unknown. In this study, in vitro activity of LAB-CFS and BAI alone and in combination was determined (checkerboard experiments, time-kill curves, and flow cytometry to investigate membrane permeability) and examined the protective effects of LAB-CFS and BAI on S. aureus-induced mastitis in mice and the impact of NF-κB signaling pathways on the emergence of mastitis. We discovered that when LAB-CFS and BAI were used together, S. aureus was more effectively treated than when LAB-CFS and BAI were used separately. Flow cytometry demonstrated that LAB-CFS and BAI work together to kill bacteria. In vivo, the usage of LAB-CFS and BAI decreased the activity of myeloperoxidase, as well as IL-6, IL-1β, and TNF-α secretion and the levels of TLR2 and p65 (NF-κB) expression. These findings suggested that LAB-CFS and BAI had a preventive effect against mastitis brought on by S. aureus. Therefore, the NF-κB signaling pathway is thought to be the likely mechanism through which LAB-CFS and BAI reduced S. aureus-induced inflammation in the mammary of cows. For the treatment of cow mastitis, LAB-CFS and BAI are likely to replace antibiotics.

The Potential of Micro-Dictum Preparation in Surface Water Reclamation Subject to Strong Anthropogenic Pressure

The aim of this research was to analyze the potential of e micro-dictum preparation containing compositions of beneficial microorganisms using this product in surface water reclamation. The experiments were carried out in 2016. The scope of this research included the analysis of the physical and chemical properties of a solid preparation; tests of the microbiological parameters of micro-dictum; an analysis of the spread of microorganisms in the aquatic environment; a study of water quality with the solid preparation; and tests of the formulation in real conditions and its potential in the reclamation of surface waters. Tests on the produced formulation were carried out in the laboratory in containers and under real conditions. Laboratory tests have shown that the analyzed preparation may introduce certain amounts of nitrogen and phosphorus into the water. However, they are not important in the case of water reclamation. Analyses of the micro-dictum preparation showed that the content of lactic acid bacteria in the center of the ball is lower compared to the outer layers. The results describing an increase in the number of lactic acid bacteria correlate with a decrease in pH and oxygen dissolved in the water with the preparation. The tests showed no negative impact on changes in the physical and chemical properties of water at the site of application. Changes in physical parameters were recorded, in particular dissolved oxygen and pH at the bottom, where the greatest microbiological activity occurred.

Fermented Rice Bran Mitigated the Syndromes of Type 2 Diabetes in KK-Ay Mice Model

Background: Diabetes is a devastating disease that causes millions of deaths. Fermented rice bran (FRB), made by fermenting rice bran with Aspergillus kawachii and a mixture of lactic acid bacteria, was hypothesized to b able to improve diabetes-related symptoms. This study aimed to investigate the effects of FRB supplementation in mitigating type 2 diabetes symptoms and identifying FRB bioactive compounds. Methods: In this study, KK-Ay mice (4 w.o. male) were used as a model for type 2 diabetes. Mice were divided into three different groups. The first group received a control diet, the second received a 12.5% non-fermented rice bran (RB) supplemented diet, and the last group was fed a 12.5% FRB-supplemented diet. Supplementation was done for 4 weeks. Results: FRB supplementation lowered the blood glucose level, OGTT, HOMA-IR, total cholesterol, liver RAGE protein, and glucokinase in KK-Ay mice. Metabolome analysis of RB and FRB showed that fermentation increased bioactive compounds in rice bran, such as GABA, L-theanine, and carnitine. It also increased the levels of various free amino acids while converting some amino acids such as arginine, tyrosine, and tryptophan into other metabolites. Conclusions: This research showed the potency of FRB supplementation as a preventive agent against type 2 diabetes.

Establishment and characterization of mouse metabolic dysfunction-associated steatohepatitis-related hepatocellular carcinoma organoids

Metabolic dysfunction-associated steatohepatitis (MASH) is a form of chronic liver inflammation associated with metabolic syndrome, such as obesity and a major cause of hepatocellular carcinoma (HCC). Multi-biotics, a soymilk fermented with lactic acid bacteria, are known to alleviate obesity by lowering lipid profile. This study aimed to establish and characterize mouse organoids derived from MASH-related HCC models to evaluate drug responses, particularly focusing on Lenvatinib resistance. Organoids were developed using mouse liver tissues subjected to a choline-deficient L-amino acid-defined high-fat diet (CDAHFD) to mimic MASH-related HCC. The study evaluated the effect of multi-biotics, a fermented product, on tumor regression and drug sensitivity. While multi-biotics did not reduce tumor burden, they enhanced the response to Lenvatinib. Additionally, repeated treatment with Lenvatinib led to the development of drug-resistant organoids. Transcriptomic analysis of these resistant organoids identified key pathways related to KRAS signaling, inflammation, and epithelial-mesenchymal transition (EMT), revealing potential targets for overcoming Lenvatinib resistance. This study provides valuable insights into MASH-related HCC progression and drug resistance, offering a model for further therapeutic research.