Lactic Acid-producing Bacteria Research Articles

Study on Enhancement of Acid Production by Combination Fermentation of Caproic Acid-producing Bacteria and Lactic Acid-producing Bacteria

A new caproic acid bacteria 20-5 (Caproicibacterium sp.) was newly screened in the laboratory, and several high-quality lactic acid bacteria A2-3 ( Sporolactobacillus fermentans ), GCB-3 ( Pediococcus acidilactici ), KR-4 ( Lactiplantibacillus plantarum ), LY-5 ( Levilactobacillus brevis ), B2-1 ( Lactiplantibacillus plantarum ) were used for exploratory compound fermentation experiments. The compound fermentation was a caproic acid bacteria (20-5) alone plus four lactic acid bacteria ( A2-3, GCB-3, KR-4, LY-5, B2-1 ), the experimental ratio was set up four groups of compound ratio of 1 : 2,1 : 1,5 : 1,10 : 1. The optimum ratio of 20-5 to B2-1 was 10 : 1, and the total acid yield reached 26.75 g / L. The best caproic acid production capacity after compounding was the 10: 1 group of 20-5 and B2-1, and the caproic acid yield was 7.22 g / L. The average lactic acid content in the fermentation broth was 4.52 g / L after compounding. After compounding, the acid production of the 1 : 1 and 5 : 1 groups of 20-5 : A2-3 and the 10 : 1 group of 20-5 : B2-1 increased compared with that of single bacteria. In the other compound groups, the acid production capacity decreased after the compound operation, and the lactic acid production generally decreased, but the caproic acid production increased, indicating that caproic acid bacteria can use lactic acid as a carbon source for fermentation and acid production activities, so that caproic acid bacteria can produce caproic acid.

301 Maxwell Lecture: Bacillus probiotics in nursery pigs: The effects of dose on gut health and performance

Abstract Weaning is one of the most stressful events in the life of a pig and critical for their health and development. To reduce the use of antibiotics and zinc oxide in nursery diets, many feed additives have been tested to demonstrate their efficacy in weaning pigs. Bacillus subtilis, a heat-resistant spore-forming bacteria, consumes oxygen in the digestive tract and can provide a favorable anaerobic environment for lactic acid-producing bacteria, resulting in their proliferation. It also produces several digestive enzymes, such as amylase, protease, and antioxidant enzymes. In addition, Bacillus species are known to alter the gut microbiome and increase the production of short-chain fatty acids in the gut. Therefore, Bacillus probiotics have been widely used in nursery diets to effectively improve growth performance and protect piglets from weaning stress and postweaning diarrhea. However, when the probiotics are supplemented in diets for weaning pigs, their efficacy is dependent on multiple factors, such as strains, the health condition of the animals, product composition, and the dose of the probiotics. There has been tremendous effort in establishing the optimal supplementation level of probiotics for nursery pigs to maximize the efficacy of their supplementation, but a high dose of probiotics could be detrimental to the gut health and microflora of nursery pigs, as it could increase the incidence of diarrhea and may have potential side effects in the immune system, antibiotic resistance, and the production of unfavorable metabolites in the gut. A study was conducted to demonstrate the effect of Bacillus probiotic supplementation for nursery pigs at the recommended and high doses (10 times greater bacterial counts than the recommended dose) compared with a control treatment with no probiotic supplementation. In the study, the Bacillus supplementation at the recommended dose did improve the early postweaning growth rate, increase the production of fecal short-chain fatty acids (acetate, propionate, and butyrate), and blood glucose concentrations, and alter the fecal microbiome. However, high-dosing probiotics in nursery diets did not show any beneficial effects that were shown in the pigs fed diets with Bacillus probiotics at the recommended dose. Bacillus-probiotic supplementation in nursery diets may enhance growth performance and benefit gut health, but a high dose of probiotics does not always lead to comparable positive effects for pigs. Therefore, it is critically important to test probiotics to optimize their efficacy and avoid unnecessary high-dosing in nursery diets, as it could be cost-ineffective and may not show benefits that can be observed with the recommended dose.

Improvement of volatile aromatic compound levels and sensory quality of distilled soju derived from Saccharomyces cerevisiae and Wickerhamomyces anomalus co-fermentation

Distilled soju, a Korean traditional alcoholic beverage, is produced by fermenting rice with a variety of microorganisms including molds, yeasts, and lactic acid-producing bacteria, followed by distillation. Our study sought to improve the quality of distilled soju through co-fermentation with Saccharomyces cerevisiae and Wickerhamomyces anomalus, known for producing volatile aromatic compounds during the early stages of fermentation. Analysis of volatile aromatic compounds in co-fermented distilled soju revealed a substantial increase in compounds with boiling points below 200 °C. Among them, ethyl hexanoate, isobutanol, and isoamyl alcohol were identified as the major volatile aromatic compounds based on Log2 fold change analyses of the volatile aromatic compound pattern. In sensory evaluation, co-fermented distilled soju received higher scores in terms of odor and overall preference. Therefore, incorporating W. anomalus may improve the quality of distilled soju.

Performance, HSP70 expression, antioxidant enzymes, oxidative DNA damage biomarkers, metabolic hormones, and intestinal microbiota of broiler chickens fed mistletoe leaf powder supplemented diets under tropical high ambient temperatures

The study investigated the impact of Mistletoe Leaf Powder (MLP) supplementation on some parameters in heat-stressed broiler chickens. The standard baseline diets, comprising four different formulations, were provided during the starter and finisher stages. Chickens were randomly assigned to the 4 dietary groups: a negative control (CON) with no supplementation, a positive control (VTC) with 200 mg/kg vitamin C, and 2 experimental treatment groups with 2500 mg/kg (MLP2) and 5000 mg/kg (MLP5) MLP supplementation. The Body Weight Gain (BWG) in MLP2 and MLP5 treatment groups was comparable (P > 0.05) to those in VTC, while the CON group exhibited significantly (P < 0.05) lower BWG. Feed consumption was significantly (P < 0.05) lower broiler chickens in the CON group compared to those VTC, MLP2, and MLP5. Heat shock protein 70 (HSP70) levels were lower in broiler chickens belonging to VTC, MLP2, and MLP5 groups compared to those in CON, and MLP2 showed no difference (P > 0.05) from MLP5 and VTC. Serum glutathione peroxidase and catalase concentrations were higher (P < 0.05) in birds belonging to MLP5, MLP2, and VTC groups compared to CON. The 8-hydroxy-2′-deoxyguanosine concentration was lower (P < 0.05) in birds of VTC, MLP2, and MLP5 compared to the CON, with VTC showing the least concentration. Serum insulin levels were higher (P < 0.05) in MLP5 compared to those in CON, while serum triiodothyronine and leptin concentrations were lower (P < 0.05) in CON compared to birds in VTC, MLP2, and MLP5. Microbiota analysis revealed that the Coliform bacteria population was higher (P < 0.05) in birds belonging to CON compared to those in VTC, MLP2, and MLP5 groups, whereas lactic acid-producing bacteria were significantly (P < 0.05) lower in birds of CON and highest in MLP2 and MLP5 groups. In conclusion, dietary supplementation of MLP at 5000 mg/kg enhanced performance, oxidative status, influenced metabolic hormones, and gut microbiota in broiler chickens raised under high ambient temperature.

Harnessing the power within: engineering the microbiome for enhanced gynecologic health.

Although numerous studies have demonstrated the impact of microbiome manipulation on human health, research on the microbiome's influence on female health remains relatively limited despite substantial disease burden. In light of this, we present a selected review of clinical trials and preclinical studies targeting both the vaginal and gut microbiomes for the prevention or treatment of various gynecologic conditions. Specifically, we explore studies that leverage microbiota transplants, probiotics, prebiotics, diet modifications, and engineered microbial strains. A healthy vaginal microbiome for females of reproductive age consists of lactic acid-producing bacteria predominantly of the Lactobacillus genus, which serves as a protective barrier against pathogens and maintains a balanced ecosystem. The gut microbiota's production of short-chain fatty acids, metabolism of primary bile acids, and modulation of sex steroid levels have significant implications for the interplay between host and microbes throughout the body, ultimately impacting reproductive health. By harnessing interventions that modulate both the vaginal and gut microbiomes, it becomes possible to not only maintain homeostasis but also mitigate pathological conditions. While the field is still working toward making broad clinical recommendations, the current studies demonstrate that manipulating the microbiome holds great potential for addressing diverse gynecologic conditions. Manipulating the microbiome has recently entered popular culture, with various diets thought to aid the microbes that live within us. These microbes live in different locations of our body and accordingly help us digest food, modulate our immune system, and influence reproductive health. The role of the microbes living in and influencing the female reproductive tract remains understudied despite known roles in common conditions such as vulvovaginal candidiasis (affecting 75% of females in their lifetime), bacterial vaginosis (25% of females in their lifetime), cervical HPV infection (80% of females in their lifetime), endometriosis (6-10% of females of reproductive age), and polycystic ovary syndrome (10-12% of females of reproductive age). Here, we review four different approaches used to manipulate the female reproductive tract and gastrointestinal system microbiomes: microbiota transplants, probiotics, prebiotics, and dietary interventions, and the use of engineered microbial strains. In doing so, we aim to stimulate discussion on new ways to understand and treat female reproductive health conditions.

The Role of Tumor and Host Microbiome on Immunotherapy Response in Urologic Cancers

Introduction &amp; Objective: The role of the microbiome in the development and treatment of genitourinary malignancies is just starting to be appreciated. Accumulating evidence suggests that the microbiome can modulate immunotherapy through signaling in the highly dynamic tumor microenvironment. Nevertheless, much is still unknown about the immuno-oncology-microbiome axis, especially in urologic oncology. The objective of this review is to synthesize our current understanding of the microbiome’s role in modulating and predicting immunotherapy response to genitourinary malignancies. Methods: A literature search for peer-reviewed publications about the microbiome and immunotherapy response in bladder, kidney, and prostate cancer was conducted. All research available in PubMed, Google Scholar, clinicaltrials.gov, and bioRxiv up to September 2023 was analyzed. Results: Significant differences in urinary microbiota composition have been found in patients with genitourinary cancers compared to healthy controls. Lactic acid-producing bacteria, such as Bifidobacterium and Lactobacillus genera, may have value in augmenting BCG responsiveness to bladder cancer. BCG may also be a dynamic regulator of PD-L1. Thus, the combination of BCG and immune checkpoint inhibitors may be an effective strategy for bladder cancer management. In advanced renal cell carcinoma, studies show that recent antibiotic administration negatively impacts survival outcomes in patients undergoing immunotherapy, while administration of CBM588, a live bacterial product, is associated with improved progression-free survival. Specific bacterial taxa, such as Streptococcus salivarius, have been linked with response to pembrolizumab in metastatic castrate-resistant prostate cancer. Fecal microbiota transplant has been shown to overcome resistance and reduce toxicity to immunotherapy; it is currently being investigated for both kidney and prostate cancers. Conclusions: Although the exact mechanism is unclear, several studies identify a symbiotic relationship between microbiota-centered interventions and immunotherapy efficacy. It is possible to improve immunotherapy responsiveness in genitourinary malignancies using the microbiome, but further research with more standardized methodology is warranted.

Evaluating Turkey-Derived Lactic-Acid-Producing Bacteria as Potential Probiotics for Use in Commercial Turkeys

Lactic-acid-producing bacteria (LAB) are widely used in the poultry industry, and they are positively associated with gut health and growth performance. Despite their wide use in poultry production, LAB appear to be highly variable in their ability to modulate poultry gut health and growth performance. Furthermore, most commercially available LAB probiotics are not host specific; thus, few poultry-specific and even fewer turkey-specific probiotics exist. The objective of this study was to use probiotic screening assays to compare relevant phenotypic differences amongst different species of turkey-derived LAB, in an effort to identify potential probiotics for use in turkey production. Different in vitro assays were used to compare the probiotic potential (phenotype) of each turkey-derived LAB isolate. Twenty-four isolates representing eight different species and five different genera were used for our experiments. These assays included acid tolerance, bile tolerance, and adhesion ability. There was variability in assay performance across many individual strains in every assay performed. Isolates between species and, in some cases, isolates within the same species, differed in their performance between the assays. Some isolates that were identified performed favorably in all the assays in this study. In conclusion, high-performing isolates were identified in this study, which hold potential for influencing turkey health and productivity.

Effect of acidification or fermentation of barley grain using Limosilactobacillus reuteri or Weissella cibaria on inositol phosphate hydrolysis in vitro

Fermentation of cereal grains may hydrolyse myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate) (InsP6) and increase concentration of lower order inositol phosphates (InsP) in vitro, thereby increasing nutrient digestibility in diets of swine and poultry. Effects of chemical acidification or fermentation with the lactic acid-producing bacteria Limosilactobacillus reuteri or Weisella cibaria of high β-glucan hull-less barley grain on pH, organic acid concentration, InsP6 hydrolysis and lower order InsP formation were assessed in vitro. In 3 batches, ground barley grain was treated in four forms balanced for water content: 1) unfermented barley (Control); 2) chemically acidified barley with lactic acid and acetic acid (0.019 L/kg barley grain at a ratio of 4:1 (volume/volume)) (ACD); 3) barley fermented with L. reuteri TMW 1.656 (Fermented with L. reuteri); and 4) barley fermented with W. cibaria 10 M FUA3120 (Fermented with W. cibaria). For 24 h in an incubator, ACD and Fermented with L. reuteri were incubated at 37 °C and Fermented with W. cibaria at 30 °C. Barley inositol phosphate6-phosphorus (InsP6-P) was 68%, 64% and 41% lower, respectively, for ACD, Fermented with L. reuteri or Fermented with W. cibaria than Control. Barley grain pH after 24 h, concentration of InsP6-P, inositol phosphate5-phosphorus (InsP5-P), inositol phosphate4-phosphorus (InsP4-P) and sum inositol phosphate6–2-phosphorus (InsP6–2-P) were lower (P < 0.05) for ACD and Fermented barley grain than Control and Fermented with L. reuteri than W. cibaria. Acetate, lactate, inositol phosphate3-phosphorus (InsP3-P) and inositol phosphate2-phosphorus (InsP2-P) concentration was greater (P < 0.05) for ACD and Fermented barley grain than Control. Lactate and InsP2-P concentration were greater (P < 0.01) for Fermented with L. reuteri than W. cibaria. Total P release, cumulative P release of InsP6-P, InsP5-P, InsP4-P and InsP3-P were greater (P < 0.01) for Fermented with L. reuteri than W. cibaria. In conclusion, lower pH in ACD and Fermentation indicated that acidification is important for InsP6 hydrolysis via intrinsic phytase activation in barley grain in vitro. Between strains, fermentation with L. reuteri maximised acidification, lactate concentration and degradation of InsP6-P, InsP5-P, InsP4-P in barley grain.

Bacteriocin producing lactic acid bacteria from camel milk and its fermented products: A review

Bacteriocin producing lactic acid bacteria from camel milk and its fermented products: A review

Development of a low pollution medium for the cultivation of lactic acid bacteria

Protein rich culture media are employed in the production of lactic acid bacteria (LAB); however, production costs are high. In this work media formulation and evaluation for LAB production were conducted considering physiological properties of lactic acid bacteria. Consumption efficiency (E), yield production (Y) and specific substrate consumption rate (qS) values as response variables were used. Four culture media were used: (1) Man Rogosa Sharp (MRS); (2) cabbage liquor (MC); (3) a new balanced culture medium (MX); and (4) MX supplemented with cabbage liquor (MXC). The culture media were evaluated using two strains: Lactobacillus acidophilus ATCC 4356 and Lactiplantibacillus plantarum ATCC 10241. The EGLU for L. plantarum was 100 % in the three media and YX/S value was 0.02 ± 0.003 in MRS and MX, while YLAC/S was 0.57 ± 0.03 in MRS and 0.51 ± 0.02 in MX. In MXC, the value obtained for YX/S was 0.07 ± 0.002 while YLAC/S was 0.47 ± 0.04. Specific glucose consumption and lactate formation rates for L. plantarum in MRS and MX media did not show significant differences. These results suggest that MX and MXC can be used for efficient production of the LAB at low cost.

The immune-adjunctive potential of recombinant LAB vector expressing murine IFNλ3 (MuIFNλ3) against Type A Influenza Virus (IAV) infection

BackgroundThe conventional means of controlling the recurring pandemics of Type A Influenza Virus (IAV) infections remain challenging primarily because of its high mutability and increasing drug resistance. As an alternative to control IAV infections, the prophylactic use of cytokines to drive immune activation of multiple antiviral host factors has been progressively recognized. Among them, Type III Interferons (IFNs) exhibit a pivotal role in inducing potent antiviral host responses by upregulating the expression of several antiviral genes, including the Interferon-Stimulated Genes (ISGs) that specifically target the virus replication machinery. To harness the immuno-adjunctive potential, we examined whether pre-treatment of IFNλ3, a Type III IFN, can activate antiviral host responses against IAV infections.MethodsIn the present study, we bioengineered a food-grade lactic acid-producing bacteria (LAB), Lactococcus lactis (L. lactis), to express and secrete functional murine IFNλ3 (MuIFNλ3) protein in the extracellular milieu. To test the immune-protective potential of MuIFNλ3 secreted by recombinant L. lactis (rL. lactis), we used murine B16F10 cells as an in vitro model while mice (BALB/c) were used for in vivo studies.ResultsOur study demonstrated that priming with MuIFNλ3 secreted by rL. lactis could upregulate the expression of several antiviral genes, including Interferon Regulatory Factors (IRFs) and ISGs, without exacerbated pulmonary or intestinal inflammatory responses. Moreover, we also showed that pre-treatment of B16F10 cells with MuIFNλ3 can confer marked immune protection against mice-adapted influenza virus, A/PR/8/1934 (H1N1) infection.ConclusionSince the primary target for IAV infections is the upper respiratory and gastrointestinal tract, immune activation without affecting the tissue homeostasis suggests the immune-adjunctive potential of IFNλ3 against IAV infections.

Oral lactoferrin administration does not impact the diversity or composition of the infant gut microbiota in a Peruvian cohort.

Lactoferrin is a protein from breast milk involved in early-life microbiome assembly. It is believed to promote the growth of lactic acid-producing bacteria and inhibit pathogens by limiting iron availability and enabling an acidic environment in the gut. Previous reports suggest that oral administration of lactoferrin in neonates promotes the increase of gut microbiota diversity and the enrichment of beneficial microbes. However, its effect on infant gut microbiota over time has yet to be thoroughly studied to fully understand its potential as a prebiotic. Using 16s rRNA gene amplicon sequencing, we analyzed the gut microbiota composition of 60 toddlers at 12-18 months of age from Lima, Peru, who received daily oral administration of lactoferrin or placebo for 6 months since enrollment. Samples were analyzed at 0, 2, and 4 months after beginning treatment. Our results show that lactoferrin treatment does not increase gut microbiota diversity over time nor affect its bacterial composition compared to the placebo group.IMPORTANCEPrevious studies have suggested that oral lactoferrin enhances diversity in the gut microbiota in infants while inhibiting the growth of opportunistic pathogens. However, the effect of lactoferrin on infant gut microbiota over time has yet to be thoroughly studied. Our study suggests that lactoferrin oral treatment in infants aged 12-18 months does not affect gut microbiome diversity and composition over time. To our knowledge, this is the first study to report the effect of lactoferrin on infant gut microbiome composition over time and helps elucidate its impact on infant health and its therapeutic potential.

Transcriptomic and metabolomic insights into the antimicrobial effect of Leuconostoc mesenteroides or lactic acid on pathogenic Gallibacterium anatis

Gallibacterium anatis (G. anatis) is an opportunistic poultry pathogen that poses a threat to human health via the food chain and can also lead to great economic losses in poultry industries. Our previous studies have demonstrated that the lactic acid-producing bacteria Leuconostoc mesenteroides QZ1178 can effectively inhibit the growth of G. anatis by acid production, but the mechanism remains unclear. The aim of the current research was to further investigate the molecular mechanism underlying this acid-induced antimicrobial effect. The TEM results showed that the cell membrane of G. anatis (GAC026) was damaged and that cells were lysed in the presence of cell-free supernatants from Leuconostoc mesenteroides (CFS) or lactic acid. Lactic acid showed a greater antimicrobial effect than CFS. In this study, the changes in the transcriptome and metabolic profile of G. anatis under acid stress at different stages were studied. Using culture medium supplemented with CFS (pH 3.6) or lactic acid (pH 3.6) at a 1:1 ratio, 677 differentially transcribed genes and 374 metabolites were detected in G. anatis. The interaction network of all identified differentially expressed genes and metabolites was constructed to outline the regulatory genes and dominant pathways in response to acid stress. The results of real-time reverse transcription quantitative PCR (RT‒qPCR) further confirmed the results of the transcriptomic analyses. Typically, succinate, citrate, L-malic acid, and oxaloacetate were reduced by acid stress in G. anatis, which suggested that lactic acid greatly disturbed energy metabolism. Overall, this work provides a comprehensive understanding of the stress response and cell death of G. anatis caused by lactic acid.Graphical

Enrichment of Lactic Acid-Producing Bacteria in the Fecal Microbiota of Patients with Ulcerative Colitis in North India

Previous studies have established the relationship between the gut microbiota and ulcerative colitis (UC); however, there is a scarcity of data on the fecal microbiome profile of patients with UC in the Indian population. This study aimed to examine the fecal microbiome profile of north Indian patients with UC ( n = 105 ), including with active disease ( n = 64 ) and in remission ( n = 41 ), compared to healthy controls ( n = 36 ), using 16S rRNA gene sequencing. Both relative abundance analysis and linear discriminant analysis effect size (LEfSe) revealed a significant enrichment of lactic acid-producing facultative anaerobic pathobionts, namely, Bifidobacterium, Lactobacillus, and Streptococcus, in patients with UC (both with active disease and those in remission). Additionally, a significant decrease was observed in anaerobic genera responsible for the synthesis of short-chain fatty acids (SCFAs), especially butyrate, such as Blautia, Roseburia, Lachnospiraceae, and Ruminococcaceae. Differential metabolic pathway analysis using PICRUSt2 confirmed a loss of SCFAs production and increased lactose and nitrate metabolism in UC patients. Biochemical analysis of fecal samples confirmed the increased colonization of nitrate-reducing microbes in UC patients, suggesting inflammation-driven dysbiosis. LEfSe and PICRUSt2 analyses revealed an enrichment of Prevotella and Blautia microbes and the upregulation of two specific metabolic pathways, sulfolactate degradation and reductive acetyl coenzyme A pathway-I, which can distinguish UC patients in remission from those with active disease. Our findings caution against the use of lactic acid-producing bacteria (LABs) and recommend the exploration of butyrate-producing microbes as probiotics to restore SCFAs levels in UC patients.

Physicochemical considerations in the formulation development of silicone elastomer vaginal rings releasing 5-nitroimidazole drugs for the treatment of bacterial vaginosis

Bacterial vaginosis (BV) is a common dysbiosis of the human vaginal microbiota characterized by depletion of hydrogen peroxide and lactic acid-producing Lactobacillus bacteria and an overgrowth of certain facultative anaerobic bacteria. Although short-term cure rates following treatment with frontline antibiotics (most notably oral metronidazole (MNZ), clindamycin vaginal cream, and MNZ vaginal gel) are generally high, longer-term recurrence rates are an issue. The development of vaginal formulations offering continuous/sustained administration of antibiotic drugs over one or more weeks might prove useful in reducing recurrence. Here, we report the manufacture and preclinical testing of matrix-type vaginal rings offering sustained release of four 5-nitroimidazole antimicrobial drugs either being used clinically or having potential in treatment of BV – MNZ, tinidazole (TNZ), secnidazole (SNZ) and ornidazole (ONZ). All four drugs showed good compatibility with a medical-grade addition-cure silicone elastomer based upon thermal analysis experiments, and matrix-type rings containing 250 mg (3.125 %w/w) of each drug were successfully manufactured by reaction injection molding. 28-day in vitro drug release studies demonstrated root-time kinetics, with daily release rates of 25, 22, 9 and 6 mg/day½ for SNZ, ONZ, MNZ and TNZ, respectively. The rank order of drug release from rings correlated with the simple molecular permeability parameter S/V, where S is the measured drug solubility in silicone fluid and V is the drug molecular volume. The relative merits of SNZ and ONZ over MNZ (the current reference treatment) are discussed. The data support development of vaginal rings for sustained release of 5-nitroimidazole compounds for treatment of BV.

The effect of probiotic Lactobacillus rhamnosus GG on Candida albicans and Candida tropicalis biofilm formation: A preliminary study

Lactobacillus rhamnosus are Gram-positive and lactic acid-producing bacteria. Meanwhile, Candida albicans and Candida tropicalis are opportunistic fungi that cause oral candidiasis. This study aimed to determine the effect of LGG on the biofilm formation of C. tropicalis and C. albicans with the hypothesis that LGG inhibits the biofilm of the yeasts. C. albicans ATCC MYA-4901 and C. tropicalis ATCC 13803 were standardised to 1x106 cells to form a mono-species biofilm. L. rhamnosus GG (LGG) was standardised to 1x107 cells, equivalent to absorbance 0.5 at OD620nm. The microorganisms were cultivated in nutrient broth in a 96-well plate and incubated at 37°C for 24 h and 48 h. Co-culture biofilm was developed by combining Candida spp. with LGG in the same well at a similar concentration as the mono-culture. Crystal violet assay was conducted to assess the biofilm biomass with absorbance measured at OD620nm wavelength. After 24 hours, polymicrobial biofilms of C. albicans with LGG decreased by 37.1 ± 9.2%. At 48 hours, it further decreased to 44.7 ± 5.9%. For C. tropicalis, co-culture biofilms with LGG decreased by 16.3 ± 5.9% and 35.7 ± 7.6% after 24 h and 48 h incubation, respectively. LGG significantly reduced C. albicans biofilm compared to C. tropicalis (P&lt;0.05). In conclusion, LGG has antibiofilm activity against C. albicans and C. tropicalis. However, further study is needed to conclude the effect against other species strains.

Agave bagasse cookies as a carbon source for lactic acid bacteria

AbstractCurrently, the Agave genus has a high economic importance because due to the products that can be obtained from these plants, with alcoholic beverage production being the most common use. The principal storage carbohydrates of agave are fructans. In this study, the utilization of Agave salmiana (green agave) and Agave atrovirens (ashy agave) bagasse cookies as a carbon source by lactic acid‐producing bacteria (LAB), as well as the acceptability of cookies by consumers was evaluated. The cookies were manufactured and digested in vitro, and fermentation by LAB was performed to evaluate pH changes, bacterial growth, and relative carbohydrate intake. The results showed that the bacteria assimilated the digested agave cookies as a carbon source, and there was no significant difference in the pH of both agave bagasse and the growth of Lacticaseibacillus casei. The highest bacterial growth of the L. lactis was observed at 12 h with green bagasse cookies. The results obtained in the present study demonstrate the potential of agave bagasse to be used as functional food ingredients.

Effect of time of sample collection after onset of diarrhea on fecal microbiota composition of calves.

The effect of time of sample collection after onset of diarrhea on the fecal microbiota composition of calves is unknown. Compare the fecal microbiota of calves with diarrhea onset on the day of sampling (D <24h), and calves having had diarrhea for >24 to 48 hours (D 24-48h). Thirty-one diarrheic calves (20 D <24h and 11 D 24-48h), 3 to 7 days of age. Cross-sectional study. Diarrhea was defined as a calf with loose feces or watery feces. Assessment of the fecal microbiota was performed by sequencing of 16S ribosomal RNA gene amplicons. Richness and diversity were not statistically different between D <24h and D 24-48h (P > .05), but bacterial membership and structure differed significantly (AMOVA, P < .001 for both comparisons). Linear discriminant analysis effect size (LefSe) showed an enrichment of Faecalibacterium, Phocaeicola, Lachnospiracea, and Lactobacillus in the feces of D <24h calves, whereas Escherichia/Shigella, Ligilactobacillus, Clostridium_Sensu_Stricto, Clostridium_Incerta_Sedis, and Enterococcus were enriched in the D 24-48h calves. Rapid changes in fecal microbiota occur during the first 48 hours of diarrhea with an enrichment of lactic acid-producing bacteria in D <24h followed by an enrichment in Escherichia/Shigella and Clostridium spp. in D 24-48h. The time from diarrhea onset to sampling appears to affect the bacterial composition. Researchers should standardize times for fecal collection based on the time of diarrhea.

Spore-Forming Lactic Acid-Producing Bacterium Bacillus coagulans Synthesizes and Excretes Spermidine into the Extracellular Space.

The effect of spermidine in extending healthy longevity has attracted attention. As people age, their ability to synthesize putrescine, the precursor of spermidine, declines, and its supplementation from the diet or gut bacteria is needed. Many bacteria synthesize spermidine, but no strains have been reported to excrete de novo synthesized spermidine from the cells. We found that Bacillus coagulans strain YF1, isolated from "nanohana-duke", excreted de novo synthesized spermidine from the cells under anaerobic conditions. This strain synthesizes spermidine from arginine via agmatine, putrescine, and carboxyspermidine in sequential reactions, and the genes encoding the enzymes responsible for these reactions have been identified. B. coagulans is a gastric acid-resistant spore-forming lactic acid-producing bacterium, known for its beneficial effects as a probiotic. It can be used to produce lactic acid fermented foods containing spermidine. The newly discovered ability to excrete de novo synthesized spermidine is the decisive feature of this bacterium.

The role of lactic acid bacteria in production of bioactive peptides in fermented milk with antioxidant and antidiabetic properties

The role of lactic acid bacteria in production of bioactive peptides in fermented milk with antioxidant and antidiabetic properties