Search Results (3,800)

A chickpea-based milk beverage containing both plant and animal proteins represents an excellent substrate for the production of biologically active peptides through fermentation. Fermentation by lactic acid bacteria (LAB) increases its nutritional value compared to the unfermented beverage while improving the digestibility and bioavailability of essential nutrients via proteolytic enzyme activity. This study investigated the production of bioactive peptides in fermented chickpea water extract using ten bacterial strains isolated from plant and animal sources. The proteolytic activity of each strain was quantified using the trinitrobenzene sulfonic acid (TNBS) method, and the presence of proteolytic genes was confirmed via agarose gel electrophoresis. Peptides released during fermentation were identified through two-dimensional electrophoresis, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and tandem mass spectrometry. To predict the potential biological activities of the studied peptide sequences, a series of in silico analyses were performed using specialized bioinformatics tools. The identified peptides were predicted to exhibit antioxidant, аntihypertensive, anticancer, antibacterial, antifungal, antituberculosis, and angiotensin-converting enzyme (ACE) inhibitory activities. Based on the results, L. fermentum SB-2 and L. sakei SD-8, were selected as promising candidates for bioactive peptide production in a chickpea water extract-based milk beverage and were subsequently applied in the beverage prototype. Full article

In many industrial dairy products, yeasts are generally regarded as contaminants. However, in traditional fermented milks, they may contribute to distinctive sensory, technological, and functional properties through associations with bacterial partners, including lactic acid bacteria (LAB). Despite this, a structured synthesis of yeast–bacterium associations across fermented milk typologies is currently lacking. To address this gap, a PRISMA-informed literature search identified 42 studies across 24 traditional fermented milks reporting paired bacterial and fungal communities. A genus-level co-occurrence analysis was used to identify which yeast–bacterium pairs were most frequently co-detected across independently documented products. The main co-occurrence patterns selected for detailed bibliographical discussion were Kluyveromyces with Acetobacter and LAB, including Lactobacillus, Streptococcus, Lentilactobacillus and Lacticaseibacillus; Pichia with LAB; Saccharomyces with LAB, especially Lactobacillus; Kazachstania with Acetobacter; Candida with Leuconostoc and Enterococcus; and Geotrichum with Pseudomonas and Enterococcus. For the selected associations, possible interaction mechanisms and implications for sensory identity, technological potential, and microbiological safety were discussed by integrating evidence from milk co-cultures, controlled model systems, and related fermented foods. Overall, this review provides a structured synthesis of yeast–bacterium associations in traditional fermented milks and identifies candidate consortia for future experimental validation. Full article

Oat (Avena sativa L.) silage fermentation often fails due to insufficient lactic acid bacteria (LAB) and low water-soluble carbohydrate content. We investigated the effects of Compound Radix Pulsatillae (CRP; 40 g/kg FM) alone or combined with a commercial LAB inoculant (containing L. plantarum, L. buchneri, and Enterococcus faecium, CRP_LA) on oat silage after 60 days. Compared to control (CK), both CRP and CRP_LA increased dry matter and water-soluble carbohydrate retention while reducing fiber components and ammonia nitrogen (p < 0.05). CRP_LA exhibited superior fermentation quality (lowest pH 4.82, highest lactic acid 47.83 g/kg DM). Using 16S rRNA sequencing and UPLC-MS/MS metabolomics integrated with weighted gene co-expression network analysis (WGCNA), we identified a brown module strongly associated with CRP_LA treatment. Six hub metabolites, belonging to flavonoids, terpenoids, alkaloids, phenolic acids, and nucleotide derivatives, were significantly elevated in CRP_LA silage and showed strong correlations with Lactobacillus abundance and fermentation quality parameters. Correlation-based network analysis revealed that these hub metabolites positively correlated with Lactobacillus abundance, lactic acid, and water-soluble carbohydrate retention, while negatively correlating with spoilage microorganisms (Enterobacter, Acinetobacter, Leuconostoc) and ammonia nitrogen. This multi-omics study provides a metabolite-centric molecular map of the silage microecosystem reshaped by CRP and LAB co-fermentation. The identified hub metabolites—with predicted antimicrobial, antioxidant, and plant-protective functions—represent potential quality markers for functional silage additive development. Mechanistic validation via targeted metabolite supplementation or pathway-specific gene expression analysis is warranted in future studies. Full article

This study investigated the effects of drying method and ingredient form on the quality characteristics of tarhana enriched with purple sweet potato (Ipomoea batatas L.). Tarhana samples were formulated with purple sweet potato in two forms (puree and freeze-dried powder) at incorporation levels of 5% and 10%, and subjected to either traditional sun-drying or freeze-drying. The drying method emerged as the dominant factor influencing product quality. Freeze-dried samples exhibited significantly lower moisture content and water activity along with a highly porous microstructure, indicating favorable physicochemical characteristics associated with product stability. Purple sweet potato incorporation enriched the phenolic profile and improved antioxidant capacity, with greater retention observed under freeze-drying conditions, particularly in powder-based formulations. Microbiological analysis revealed that freeze-drying preserved higher populations of lactic acid bacteria while suppressing yeast and mold growth. Instrumental aroma analysis demonstrated a clear shift in volatile composition depending on processing conditions, with freeze-drying yielding a more favorable aroma profile compared to sun-drying. Freeze-drying was identified as a superior method for preserving bioactive compounds, microbial viability, and aroma quality in purple sweet potato-enriched tarhana. These findings highlight the functional potential of purple sweet potato as an ingredient in traditional fermented foods and provide a basis for the development of high-quality tarhana formulations. Full article

Uterine infections (metritis and endometritis) are a leading cause of culling and reproductive failure in transition dairy cows, and antibiotic-resistant Gram-negative pathogens limit conventional therapy. This randomized, controlled, multi-farm field trial evaluated whether four intravaginal infusions of a host-adapted lactic acid bacteria (LAB) cocktail (Lactobacillus sakei FUA3089, Pediococcus acidilactici FUA3138, P. acidilactici FUA3140; 10⁸–10⁹ cfu/dose) at −3, −2, +3, and +4 weeks relative to calving reduce periparturient disease and improve milk production. A total of 526 pregnant cows (426 Holstein, 100 Jersey) from four commercial Alberta farms (automatic-milking, parlor, and certified-organic systems) were block-randomized within farm and parity to TRT1 (saline; n = 175), TRT2 (saline + skim milk; n = 176), or TRT3 (LAB cocktail in saline + skim milk; n = 175). Uterine infection incidence was assessed by Metricheck™ mucus scoring and transrectal ultrasonography at +3 and +4 weeks postpartum. Across the principal peripartum infectious outcomes, TRT3 showed a consistent protective effect: uterine infection incidence was lowest in TRT3 (18.8% vs. 25.1% in pooled controls; OR = 0.69; 95% CI, 0.44–1.09; an approximately 25% relative reduction; exact p = 0.12), and this metritis signal was additionally supported by a repeated-measures mixed model accounting for farm, parity, and week (p = 0.0175), although the Bonferroni-adjusted pairwise contrasts were tendencies (adjusted p ≈ 0.12), and the effect did not differ by parity (treatment × lactation interaction, p = 0.97). Subclinical mastitis was numerically lower in TRT3 than in pooled controls (5.3% vs. 8.9%; OR = 0.57; 95% CI, 0.27–1.24; exact p = 0.16), whereas retained placenta, milk fever, displaced abomasum, and lameness showed no clear cow-level treatment effect in the cow-level exact analyses. Milk yield increased significantly in multiparous cows, which produced 4.6 L/day more milk than TRT1 and 3.22 L/day more than TRT2 over the first 50 days in milk (p < 0.01 for both contrasts; treatment × parity interaction, p = 0.01). No effect was seen on milk composition, uterine involution, or reproductive performance. The trial supports intravaginal LAB as a candidate antibiotic-free prophylactic whose response depends on farm- and cow-level contexts and whose mechanisms require confirmation through microbiological and metabolic measurements. Full article

Plastics and microplastics are widespread in the environment, yet knowledge about their impact on agricultural soils, including their microbiological properties, remains limited. Therefore, this study addressed the research question regarding the impact of secondary microplastics, biodegradable poly(lactic acid) (PLA) mulch film, and low-density polyethylene (LDPE) film on the abundance, structure, and functions of soil bacteria, with particular emphasis on the presence of bacterial pathogens. PLA and LDPE were applied to the soil at a dose of 4 g kg⁻¹ d.m. of soil. The aim of the experiment was to evaluate and compare the effectiveness of soil bioaugmentation with the Pseudomonas umsongensis strain and its biostimulation with humic acids in mitigating the negative effects of microplastics. The response of culturable bacteria revealed high sensitivity of organotrophic bacteria to both microplastics, with a stronger inhibitory effect from PLA, as well as stimulation of actinomycetes. 16S rRNA gene amplicon sequencing indicated that the materials differentially influenced the bacterial response. PLA most strongly stimulated Actinobacteriota and favored the dominance of Bacillus and Limnochorda, whereas LDPE promoted the growth of Actinobacteriota and Chloroflexota as well as genera KD4-96 and 1921-2. Both microplastics were colonized by potential pathogens, including Bacillus, Mycobacterium, Ralstonia, and Cupriavidus. PLA additionally stimulated the proliferation of Leifsonia sp. and Curtobacterium sp., while both PLA and LDPE reduced the abundance of Enterobacter sp. and Herbaspirillum sp. Bioaugmentation using the Pseudomonas umsongensis strain was more effective in restoring the balance of the soil microbiome than biostimulation with humic acids. The results indicate that microbial preparations based on Pseudomonas umsongensis may serve as an important tool in restoring the balance of soil exposed to microplastics. Full article

Colorectal cancer (CRC) is intricately linked to gut microbiota dysbiosis and tryptophan (Trp) metabolic dysregulation. This study aimed to clarify the role and mechanisms of 20(S/R)-ginsenoside Rh1 in suppressing colorectal cancer through the regulation of gut microbiota and Trp metabolism. Azoxymethane/dextran sulfate sodium (AOM/DSS)was employed to induce a CRC mouse model, followed by treatment with 20(S/R)-ginsenoside Rh1 at 100 mg·kg⁻¹·day⁻¹ for 6 weeks. 20(S/R)-ginsenoside Rh1 significantly reduced the disease activity index (DAI) score, restored colon length, and decreased tumor count. 20(S/R)-Ginsenoside Rh1 ameliorated gut dysbiosis by increasing gut microbial diversity and elevating the prevalence of beneficial bacteria, including Lactobacillus, and stimulated the production of indole derivatives, including indole-3-propionic acid (IPA), indole-3-acetic acid (IAA), and indole-3-lactic acid (ILA) by enriching Trp -metabolizing bacteria such as Lactobacillus reuteri. These changes further activated the AhR/CYP1A1/IL-22 and PXR/TLR4 pathways, upregulated the expression of intestinal tight junction proteins, suppressed the secretion of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IFN-γ, and elevated the levels of the anti-inflammatory cytokine IL-10. Furthermore, 20(S/R)-ginsenoside Rh1 reduces the serum kynurenine (Kyn)/Trp ratio, downregulates the expression of forkhead box P3 (FoxP3), a marker of regulatory T (Treg) cells, and increases the number of CD8⁺ T cells by inhibiting the expression of indoleamine 2,3-dioxygenase 1 (IDO1) in colonic tissue. In conclusion, 20(S/R)-ginsenoside Rh1 showed potential anti-CRC activity, with our study observing links between its action and gut microbiota structure regulation, Trp metabolism modulation, AhR/PXR-mediated intestinal barrier activation, and IDO1-related immune suppression reversal. Full article

The development of novel plant-based products using unconventional food matrices increases the risk of introducing mycotoxins into the food system. Biological detoxification methods, particularly those involving lactic acid bacteria (LAB), are considered sustainable and safe strategies. In this study, we screened 142 plant-derived LAB strains across 17 species for their fermentation performance and mycotoxin removal capacity during faba fermentation. Among them, 84 strains showed rapid acidification. The plating of 11 selected strains confirmed robust growth with cell densities ranging from 4 × 10⁸ to 2.18 × 10⁹ CFU/mL. Screening for aflatoxin B1 (AFB1) removal in complex medium identified several strains that could reduce AFB1 in the supernatant. However, complete toxin extraction after faba fermentation indicated that AFB1 was not enzymatically degraded. Similarly, no significant degradation of ochratoxin A or zearalenone was observed during faba fermentation. Additionally, a cell binding test with 11 selected strains showed that all strains bound AFB1, with efficiencies from about 10% to 35%. Notably, Lentilactobacillus hilgardii NFICC857 demonstrated the highest binding capacity, which has never been reported before. Our study provides preliminary insight into plant-derived LAB in mycotoxin removal. Given the vast unexplored diversity of LAB in nature, the discovery of novel strains with enhanced mycotoxin-binding capacity and potential enzymatic degradation remains promising. Full article

Background/Objectives: The microbiota–gut–brain axis (MGBA) plays a pivotal role in cognitive function, making psychobiotics a promising strategy for managing neurodegenerative diseases. Lactic acid bacteria (LAB) from traditional fermented foods represent a valuable source of candidate strains, and multi-strain consortia may offer enhanced therapeutic efficacy through synergistic effects. This study evaluated the functional and psychobiotic potential of three lactic acid bacteria (LAB) strains isolated from fermented foods, assessed as monocultures and a multi-strain consortium (MIX). Methods: The research encompassed an initial screening of the individual strains and the MIX, assessing their adhesion to mucin, stability in a static in vitro digestion model, and amino acid profiling. Subsequently, the LAB MIX underwent long-term evaluation in a dynamic gastrointestinal model (SHIME^®) inoculated with microbiota from a patient with Alzheimer’s disease, during which alterations in gut microbiota composition and amino acid metabolism were analyzed. Results: The LAB MIX demonstrated high stability under digestive stress and effective mucoadhesive properties. Furthermore, the consortium demonstrated a distinct metabolic signature, driving enhanced functional effects that complemented or exceeded those observed in individual monocultures. In the SHIME^® model, the MIX induced significant, site-specific shifts in microbial composition, notably increasing lactobacilli abundance. These taxonomic changes correlated with an enriched metabolic profile, including elevated levels of GABA precursors and amino acids with antioxidant potential, which are crucial for MGBA modulation. Conclusions: These results identify the LAB consortium as a compelling psychobiotic candidate. Further in-depth in vivo and clinical studies are required to validate its therapeutic potential for MGBA modulation. Full article

Lactic acid bacteria (LAB), as important probiotics, face challenges in applications from bacteriophage infection and the instability of foreign genetic elements. Although Gabija systems and their GajA nuclease components have been characterized in model bacteria, their distribution, biochemical properties, and defensive functions in LAB remain largely unexplored. Here, we provide the first systematic characterization of a naturally occurring Gabija system from Ligilactobacillus salivarius Ren and clarify its distribution among LAB. Approximately 9.3% of LAB strains encode the Gabija system, which exists as a gajA-gajB gene cluster. We found that the Gabija system originated independently in different bacterial lineages. The GajA of L. salivarius Ren (LsGajA) was purified and exhibited non-specific nuclease activity that could efficiently cleave various nucleic acid substrates, including plasmids and linear double-stranded DNA (dsDNA). This activity displayed a temperature-dependent profile, with high activity observed from 45 to 60 °C and at pH 8.0. Mg²⁺ markedly enhanced its degradative nuclease activity, whereas high concentrations of dNTPs inhibited DNA cleavage. LsGajA exhibited substrate-dependent differences in cleavage efficiency, indicating that substrate origin and associated physicochemical features may influence its activity. Additionally, we demonstrate that LsGajA exhibits exceptional stability as a nuclease, retaining activity under a wide range of conditions. The LsGabija system significantly enhanced the ability to reject foreign plasmids and provided strong resistance to the bacteriophage T5 in Escherichia coli. This study provides the first systematic biochemical and functional characterization of the Gabija system in LAB, advancing our understanding of this prokaryotic defense system and highlighting its potential for industrial applications. Full article

Biofilms are structured communities of microorganisms embedded in a self-produced extracellular polymeric substance (EPS) matrix, whose development significantly enhances microbial resistance to antibiotics, disinfectants, and host immune defenses, posing major challenges in clinical, industrial, and environmental settings. Compared with planktonic cells, biofilm-associated microorganisms can exhibit up to 10- to 1000-fold increased tolerance to antimicrobial agents, contributing to the persistence of biofilm-associated infections (BAIs). These infections remain difficult to eradicate due to reduced penetration, altered metabolic states, and the presence of dormant or persister cells. Anti-biofilm strategies can be broadly classified into physical approaches (e.g., ultrasound, mechanical stress, and light-based approaches) that target biofilm structure; chemical and enzymatic methods (e.g., EPS-degrading enzymes) that destabilize the matrix; and biological and molecular strategies (e.g., quorum-sensing (QS) inhibitors, anti-virulence agents, bacteriophages, phage-derived antimicrobial molecules, antimicrobial peptides, and natural bioactive compounds) that modulate biofilm development and integrity by targeting regulatory pathways and matrix stability through distinct mechanisms of action. Natural compounds, including lactoferrin, lactoferrin-derived peptides, and probiotic and postbiotic fractions of lactic acid bacteria (LAB), as well as plant-derived metabolites, have shown promising anti-biofilm effects, with efficacy often enhanced through complementary or potentially synergistic interactions. However, despite these advancements, clinical translation remains limited. For example, BAIs account for approximately 80% of chronic infections, with high recurrence rates and therapeutic failure reported in device-associated infections and chronic wounds. These limitations highlight the need for clinically translatable, multimodal approaches that integrate structural biofilm disruption, antimicrobial targeting, and host response modulation to design more effective and sustainable anti-biofilm strategies. Full article

Naturally fermented tofu whey is a nutrient-rich byproduct of tofu production that harbors diverse lactic acid bacteria (LAB) with potential probiotic properties. However, the antioxidant mechanisms of these LAB, particularly the roles of different cellular fractions and their metabolic basis, remain unclear. This study aimed to isolate LAB from naturally fermented tofu whey and evaluate their antioxidant activities across cellular fractions, combining in vitro assays, 16S rDNA-based identification, metabolomic profiling, and cellular validation to elucidate the underlying mechanisms. Six LAB strains were isolated and screened for 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging capacity and environmental stress tolerance. Among the identified isolates, Lactiplantibacillus plantarum MCS1903 exhibited the highest extracellular antioxidant activity. Non-targeted metabolomic analysis of cell-free supernatant revealed distinct metabolic profiles compared with the MRS control, with significant enrichment of antioxidant-related metabolites and pathways. In Caco-2 cells, MCS1903 supernatant (<5%, v/v) showed no significant cytotoxicity and effectively alleviated H₂O₂-induced oxidative stress by modulating the Nrf2/Keap1-HO-1 signaling pathway. These findings indicate that tofu whey is a valuable source of functional LAB, and MCS1903 represents a promising candidate for probiotic and functional food applications, supporting the valorization of tofu whey and development of natural antioxidant probiotics derived from fermented food byproducts. Full article

This study evaluated Lactococcus lactis RDN-1 and its inorganic selenium-enriched derivative in hybrid sturgeon, focusing on growth performance, immune responses, and intestinal health. A 21-day feeding trial was conducted with four groups: control (CK), L. lactis RDN-1 (R), inorganic selenium-enriched L. lactis RDN-1 (RX), and enrofloxacin (E). All supplemented groups exhibited significantly improved weight gain. The R group attained the highest levels of most essential and total amino acids, whereas the RX group achieved the highest methionine content. In contrast, the E group exhibited significantly lower levels of most amino acids compared to the R and RX groups. The R group suppressed the abundance of Proteobacteria while enriching beneficial genera such as Lactococcus, thereby enhancing functional capacities related to energy metabolism, amino acid biosynthesis, and signal transduction. The RX group promoted Firmicutes and Bradyrhizobium, and exhibited superior functional characteristics in antioxidant capacity and secondary metabolite biosynthesis. Moreover, the RX group down-regulated IL-6, demonstrating a balanced immunomodulatory effect with anti-inflammatory potential. In conclusion, L. lactis RDN-1 and its selenium-enriched derivative represent promising antibiotic alternatives. L. lactis RDN-1 alone offers more comprehensive effects, whereas inorganic selenium supplementation partially impairs its overall performance but achieves more accurate immune regulation. This work provides a scientific foundation for the precise application of L. lactis. Full article

Spoilage in vacuum-packaged chicken breast is driven by coupled microbial succession and physicochemical changes that cannot be adequately described by a single indicator. In this study, MALDI-TOF MS-based species-level identification of culturable isolates was integrated with microbiological counts (total viable count, lactic acid bacteria, yeasts and molds, and Enterobacteriaceae), physicochemical parameters (pH, water activity, CIE $L^{\ast }{a}^{\ast }{b}^{\ast }$, and total volatile basic nitrogen (TVB-N)), and sensory evaluation of odor, appearance/color, surface texture/slime and overall acceptability (trained panel, $n=8$) during 15 days of storage at 4 °C. Associations among variables were assessed using Spearman correlation analysis. MALDI-TOF MS identified 625 isolates belonging to 67 species across 19 families. The microbial community shifted from an initially diverse flora toward late-stage dominance by Latilactobacillus sakei, L. curvatus, Hafnia alvei, Serratia spp., Carnobacterium maltaromaticum and Brochothrix thermosphacta, while Candida zeylanoides persisted throughout storage. TVC exceeded 7 log CFU/g, and TVB-N increased from 10.65 to 23.20 mg N/100 g ($p<0.05$). TVB-N showed strong positive correlations with all microbial groups ($r_s\ge 0.90$, $p<0.01$) and with seven microbial families at the family level. Hafniaceae dominance coincided with a transient mid-storage decrease in pH, consistent with the deaminative activity of H. alvei. $b_{in}^{\ast }$ showed significant associations with four microbial families and with both microbial counts and TVB-N, supporting its value as a practical spoilage indicator. Sensory evaluation identified Day 13 as the rejection point, corresponding to TVC of 6.79 log CFU/g and TVB-N of 20.80 mg N/100 g, with simultaneous deterioration of odor and appearance, in contrast to the sequential pattern typically reported under aerobic conditions. To our knowledge, this is the first study to integrate time-resolved MALDI-TOF MS-based family-level profiling with physicochemical and sensory monitoring in vacuum-packaged chicken breast stored at 4 °C, offering a condition-specific framework for shelf-life assessment. Full article

Probiotic lactic acid bacteria are widely recognized for their health-promoting effects. However, the use of live microorganisms may pose safety concerns and stability limitations. Consequently, postbiotics, defined as inactivated microbial cells and/or their components, have emerged as a promising alternative. This study integrates genome-guided evaluation of probiotic potential, experimental validation of in silico predictions and process optimization for the production of inactivated Lactiplantibacillus plantarum DM1 and KK1 cells as postbiotics. Genome mining identified genes and gene clusters associated with metabolic versatility, antimicrobial activity, gastrointestinal stress tolerance, adhesion and prebiotic substrate utilization. Building on these findings, to generate postbiotics, the efficiency of thermal, enzymatic, mechanical and radiation-based inactivation methods was evaluated in bacterial suspensions prepared in three dairy by-product matrices: milk permeate, sweet whey and sour whey. Complete inactivation of both strain cells was achieved by thermal treatment (3 min pasteurization), γ-irradiation (3 kGy), and combined lysozyme–pasteurization treatment, whereas other treatments showed partial and matrix-dependent effects. Matrix composition significantly influenced treatment efficacy, suggesting a protective role of food components used. These findings highlight the importance of combining genome mining for potential probiotic strain characterization with robust, matrix-adapted inactivation strategies for the development of stable postbiotic formulations. Full article