Search Results (47)

Enterotoxigenic Escherichia coli (ETEC) causes severe intestinal infections in animals and threatens public health under the One Health framework. Most conventional studies focus on acute short-term ETEC infection, while natural persistent colonization oftern induces chronic intestinal mucosal compensatory remodeling in hosts. This study evaluated the protective effects of giant panda-derived Weissella confusa BSP201703 against chronic ETEC-induced intestinal damage using a giant panda fecal microbiota-associated (GPF) mouse model. Seventy-two Kunming mice were divided into six groups: blank control (C1), GPF control (C2), ETEC control (C3), and three W. confusa BSP201703 groups at low (1.0 × 10⁷ cfu/mL, W1), medium (1.0 × 10⁸ cfu/mL, W2), and high (1.0 × 10⁹ cfu/mL, W3) doses. Mice were first subjected to continuous ETEC challenge for 5 days to establish stable chronic intestinal injury, followed by a subsequent 5-day intervention with probiotic or sterile PBS for repairing existing damage. Growth performance, histopathology, serum D-lactate, SIgA, tight junction genes (ZO-1, Occludin, Claudin-1), and gut microbiota were analyzed. Histomorphologically, the chronic ETEC challenge induced compensatory increases in ileal villus height and crypt depth, which differed from typical acute necrotic atrophy. W. confusa BSP201703 mitigated ETEC-induced damage, reduced serum D-lactate (p < 0.05), increased SIgA, and upregulated tight junctions (p < 0.05). Microbial results demonstrated that medium-dose W2 maximized microbial diversity, while W1/W3 selectively enriched beneficial Bacteroidetes, Clostridium cluster IV, and Clostridium cluster XIVa taxa, confirming that moderate doses yielded optimal protection. In conclusion, W. confusa BSP201703 relieves ETEC injury by enhancing intestinal barrier function and regulating gut microbiota, highlighting its potential as a wildlife probiotic for One Health applications. Full article

Industrial food processing generates substantial byproducts, resulting in environmental challenges and economic losses. This study explores the biovalorization of sugar-rich barbecue sauce waste streams through fermentation to create value-added ingredients for sauce production and promote circular economy practices. The barbecue stream was diluted with water at 25 and 50% incorporation levels and fermented at room temperature for 12 days using a microbial consortium comprising three lactic acid bacteria (Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Weissella confusa) and one yeast (Saccharomyces boulardii). Laboratory-scale fermentation was monitored by measuring pH, total soluble solids, titratable acidity, sugar consumption, and metabolite production. The consortium demonstrated effective performance, reducing pH and TSS and increasing titratable acidity for both incorporation levels over 12 days. The fermented samples were characterized by their antioxidant capacity, color, protein content, humidity, and viscosity. The total phenolic content and antioxidant activity (DPPH) increased significantly (p < 0.05), and the viscosity increased by 254.3% and 48.3% for the fermented streams with 25% and 50% incorporation, respectively. Antimicrobial assays revealed that the fermented samples inhibited typical spoilage bacteria and yeast. This work highlights the potential of fermentation to upcycle barbecue waste, with antimicrobial characteristics contributing to extended shelf life, sustainable food production, and circular economic practices. Full article

Broad bean paste (BBP), a traditional Chinese fermented condiment, often suffers from inconsistent quality during spontaneous fermentation. In this study, Weissella confusa KUST3424 and Bacillus subtilis KUST4527 were isolated from BBP and evaluated as starter cultures, either individually or in combination. Flavor characteristics were analyzed using an electronic nose, electronic tongue, and GC–MS combined with odor activity value (OAV) calculations. Results showed that 13 key flavor compounds with OAVs greater than 1 were identified as major contributors to the overall aroma of fermented BBP juice (FBPJ). Moreover, inoculated groups exhibited distinct flavor profiles compared with natural fermentation, with the co-culture producing the most pronounced improvements. The mixed fermentation markedly enhanced desirable alcohols and esters, including significant increases in isoamyl alcohol (125.87%), 2-furanmethanol (128.91%), phenethyl alcohol (354.06%), and 4-vinylguaiacol (150.99%). In addition, compounds such as acetoin, guaiacol, ethyl hexanoate, and ethyl benzoate were newly generated in the co-culture group, while the diversity and total content of esters increased significantly from 0.52% to 9.69%. These findings demonstrate that the combined use of W. confusa KUST3424 and B. subtilis KUST4527 as starter cultures can effectively enhance the complexity and overall quality of BBP flavor. This co-culture strategy shows promise for enhancing flavor control and consistency in industrial-scale BBP production. Full article

Cottonseed meal (CSM), an important protein-rich feed ingredient, faces limited utilization in livestock diets due to the presence of free gossypol (FG)—a potent antinutritional toxin. This study aimed to isolate FG-degrading bacteria from the cotton bollworm, Helicoverpa armigera, and to evaluate their potential as probiotics in vitro. Eleven gossypol-tolerant strains were isolated from the gut of Helicoverpa armigera larvae using a screening medium containing gossypol as the sole carbon source. Among these, four lactic acid bacteria strains—Pediococcus acidilactici GM-NP, Pediococcus acidilactici GM-P, Enterococcus faecalis GM-6, and Weissella confusa GM-2—were selected for further investigation of their gossypol degradation capacity and probiotic potential. Probiotic characterization revealed that all strains exhibited tolerance to gastrointestinal fluids and bile salts, safe γ-hemolysis, and strong auto-aggregation, cell surface hydrophobicity, and antimicrobial activity. Solid-state fermentation of CSM with these strains reduced FG content by more than 50%, increased crude protein by over 6%, and elevated acid-soluble protein content by more than 70%, thereby effectively enhancing the nutritional quality of CSM. This study is the first to demonstrate that bacterial isolates from the gut of Helicoverpa armigera possess concurrent high-efficiency gossypol degradation and probiotic properties, providing a theoretical foundation for developing novel probiotic resources and promoting the safe utilization of CSM. Full article

Xylanases play a crucial role in bio-transforming sustainable agricultural polymers into xylose-based oligosaccharides, which have great potential in various biotechnology applications. Nevertheless, the application of bacterial xylanase is hindered by the high cost of developing recombinant bacteria to overcome the low activity and narrow pH stability. Considerable efforts have been made to discover and explore new wild bacterial strains that produce highly effective and environmentally sustainable extracellular xylanase enzymes for various targeted biotechnological and industrial applications. Lactic acid bacteria (LAB) have recently been proven to be versatile producers of extracellular hydrolytic enzymes. Therefore, this study aimed to isolate and characterise extracellular xylanase-producing LAB (EXLAB) from plant sources. The specific extracellular xylanase activity was determined across a wide pH range, from acidic to alkaline. Subsequently, the expression of xylanase genes of EXLAB grown under acidic and alkaline conditions was determined by quantitative reverse transcription polymerase chain reaction. A total of 45 putative LAB were isolated from radish, gundelia and rhubarb plants. They were identified by phenotypic and genotypic approaches. However, only 15 LAB isolates were confirmed as EXLAB. Weissella confusa and Pediococcus pentosaceus were the most common species among the identified EXLAB. The XylW (~196 bp) and XylP (189 bp) xylanase genes were then amplified from W. confusa and P. pentosaceus, respectively. P. pentosaceus G4 demonstrated the most versatile extracellular xylanase production that was active from pH 5 to pH 8. However, a significant increase in extracellular xylanase gene expression (13.45-fold) at pH 5 was noted as compared to pH 8. Similarly, P. pentosaceus G4 also exhibited the highest extracellular xylanase activity (0.88 U/mg) at pH 5. This study reveals the potential of P. pentosaceus G4 as an eco-friendly and novel extracellular xylanase producer possessing broad pH stability. The robust gene expression and activity of extracellular xylanase imply P. pentosaceus G4 is a promising candidate for sustainable enzymatic processes essential for the environmentally friendly enzymatic reactions and applications. Full article

Bacteriocins from lactic acid bacteria have attracted considerable attention as natural alternatives to conventional antimicrobial agents. Weissellicin LM85, a bacteriocin purified from Weissella confusa LM85, has been less extensively studied in terms of its mechanism of action and potential applications. In this study, purified weissellicin LM85 exhibited potent inhibitory effects against Gram-positive bacteria, with minimum inhibitory and bactericidal concentrations determined against Micrococcus luteus MTCC106. Time-kill assays and fluorescence staining indicated a concentration-dependent reduction in cell viability, accompanied by membrane disruption. Further analyses revealed potassium ion efflux, dissipation of membrane potential (Δψ) and pH gradient (ΔpH), genomic DNA fragmentation, and pronounced morphological alterations in target cells. These findings are strongly suggestive of membrane-targeted bactericidal activity, likely involving pore-forming effects. In addition, weissellicin LM85 inhibited both growth and biofilm formation of Salmonella enterica subsp. enterica serovar Typhimurium ATCC13311 and Staphylococcus aureus subsp. aureus ATCC25923. Mechanistic analyses revealed the disruption of cell membrane integrity, leakage of potassium ions, cytoplasmic contents, and non-specific DNA degradation, indicating a multifaceted antibacterial mode of action. These findings highlight weissellicin LM85 as a promising natural antimicrobial with potential applications in food preservation and the control of foodborne pathogens and biofilm-associated infections. Further studies on cytotoxicity and in vivo efficacy are required to advance its practical application. Full article

Weissella, a genus of Gram-positive, facultatively anaerobic lactic acid bacteria, has emerged as a significant component of human microbiota with diverse biotechnological and therapeutic applications. This narrative review examines the current state of knowledge regarding Weissella taxonomy, physiological characteristics, and functional properties based on research spanning from 1993 to present. Weissella species demonstrate remarkable versatility, producing bioactive metabolites including exopolysaccharides (EPS), bacteriocins, and organic acids that confer antimicrobial, antioxidant, and anti-inflammatory properties. These bacteria show significant potential in food fermentation, probiotic applications, and therapeutic interventions for gut health, obesity, and inflammatory conditions. However, challenges persist regarding strain-specific pathogenicity, particularly with W. confusa as an opportunistic pathogen, and the need for comprehensive safety evaluations. Current limitations include variability in probiotic efficacy, incomplete understanding of host-microbe interactions, and gaps in metabolic pathway characterization. This review provides a foundation for advancing Weissella research and applications while highlighting critical areas requiring further investigation to fully harness their biotechnological and therapeutic potential. Full article

This study focuses on the identification of three lactic acid bacteria isolates obtained from traditional Algerian fermented wheat as well as the evaluation of their biological activities, mainly their probiotic, antimicrobial, anti-inflammatory, and antioxidant properties. These isolates were identified through phenotypic and genotypic characterizations. It was found that isolate LB3 was Lactiplantibacillus plantarum, while isolates LB1 and LB2 were identified as Weissella confusa. It was observed that the strains LB1, LB2, and LB3 are capable of maintaining their growth at pH 3.0 and in bile salts after 4 h, with individual survival rates ranging from 41% to 90% depending on the strain. Furthermore, their co-aggregation capacity with Staphylococcus aureus ATCC6528 indicated a percentage higher than 50%. The three strains displayed powerful inhibitory effects against pathogenic bacteria, showing inhibition rates of 5% to 40%. They also exhibited significant anti-inflammatory activity ranging from 20% to 39%. All three lactic acid bacteria (LAB) isolates exhibited significant antioxidant activity. Their intact cells demonstrated a high ability to scavenge DPPH radicals and possessed substantial ferric reducing power, while their intracellular extracts showed high levels of glutathione (GSH). Additionally, they exerted a protective effect against plasma lipid peroxidation, with inhibition rates ranging from 20% to 39%. These findings suggest that these strains possess promising probiotic potential as future therapeutic agents to be used in the development of novel functional fermented foods. Full article

Antibiotic overuse has contributed to the emergence of multidrug-resistant (MDR) bacteria, posing a serious public health threat. Pets may act as reservoirs of MDR bacteria, with the potential to transmit these pathogens to humans. This study aimed to identify probiotic alternatives to antibiotics by isolating and evaluating lactic acid bacteria (LAB) from feline milk. In addition to conventional in vitro assessments such as growth kinetics, adhesion ability, safety, and antipathogenic activity, this study also evaluated the antioxidant capacity and production of beneficial metabolites. Three LAB strains were isolated from feline milk, including two strains of Lactobacillus plantarum (M2 and M3) and one strain of Weissella confusa (M1). Resistance assays revealed that strains M2 and M3 exhibited high survival rates under stress conditions, including exposure to bile salts, acidic environments, artificial intestinal and gastric juice. Notably, strain M3 demonstrated strong auto-aggregation ability (73.39%) and high hydrophobicity toward trichloromethane (62.16%). It was also nonhemolytic and susceptible to various β-lactam antibiotics. Furthermore, strain M3 exhibited potent antimicrobial activity in both co-aggregation and Oxford cup assays. Overall, L. plantarum M3 displayed superior probiotic properties, suggesting its potential as an adjunct or alternative to antibiotics in managing MDR bacterial infections in cats. Full article

High potential is attributed to the concomitant use of probiotics and prebiotics in a single food product, called “synbiotics”, where the prebiotic component distinctly favours the growth and activity of probiotic microbes. This study implemented a detailed comparison between the prebiotic effect of Fructooligosaccharides (FOSs) and Raffinose family oligosaccharides (RFOs) on the viable count of bacteria, hydrolysis into monosaccharides, the biosynthesis of short-chain fatty acids and sensory attributes of soymilk fermented with 1% (v/v) co-cultures of Lacticaseibacillus rhamnosus JCM1136 and Weissella confusa 30082b. The highest viable count of 1.21 × 10⁹ CFU/mL was observed in soymilk with 3% RFOs added as a prebiotic source compared with MRS broth with 3% RFOs (3.21 × 10⁸) and 3% FOS (6.2 × 10⁷ CFU/mL) when replaced against glucose in MRS broth. Raffinose and stachyose were extensively metabolised (4.75 and 1.28-fold decrease, respectively) in 3% RFOs supplemented with soymilk, and there was an increase in glucose, galactose, fructose (2.36, 1.55, 2.76-fold, respectively) in soymilk supplemented with 3% FOS. Synbiotic soymilk with 3% RFOs showed a 99-fold increase in methyl propionate, while the one supplemented with 3% FOS showed an increase in methyl butyrate. The highest acceptability based on the sensory attributes was for soymilk fermented with 2% RFOs + 2% FOS + 2% table sugar + 1% vanillin (7.87 ± 0.52) with high mouth feel, product consistency, taste, and flavour. This study shows that the simultaneous administration of soy with probiotic bacteria and prebiotic oligosaccharides like FOSs and RFOs enhance the synergistic interaction between them, which upgraded the nutritional and sensory quality of synbiotic soymilk. Full article

The biotechnological potential of the lactic acid bacterial genus Weissella has not been fully unearthed. Since Weissella have not been tested against Fusaria and their mycotoxins, newly isolated Weissella confusa strains were characterized and tested for their antifungal capacities on Fusarium plant pathogens. W. confusa BF2 and ML2 successfully inhibited Fusarium verticillioides NCIM 1100, F. verticillioides NCIM 1099, Fusarium graminearum MTCC 2089, and Fusarium oxysporum MTCC 284 in co-cultures. Ethyl acetate extracts of the cell-free culture supernatants (CFCS) of W. confusa also exhibited antifungal activity against the tested fungal cultures. The main mycotoxins of Fusaria were tested against the Weissella isolates. In MRS broth, W. confusa BF2 was resistant to the Fusarium mycotoxins (deoxynivalenol, zearalenone, T2, and fumonisin B1), while the ML2 strain showed 22.1–24.5% growth inhibition. Meanwhile, neither bacterium showed potential in mycotoxin reduction. The study highlighted that W. confusa BF2 and ML2 and their CFCS are suitable for Fusarium growth inhibition, as shown on surface-sterilized peanuts and wheat grains, but not for mycotoxin elimination. Full article

Controlled fermentation carried out by selected starters might enhance the safety, nutritional, and biological profiles of non-dairy fermented products. This research aims to study the biological potential and impact on the human gut microbiota of a novel fermented finger millet-based product. Finger millet (Eleusine coracana), suspended in an aqueous sucrose-based solution, was fermented by Weissella confusa 2LABPT05 and Lactiplantibacillus plantarum 299v (1%, 1:1 ratio (v/v)), at 30 °C/200 rpm in an orbital incubator until pH ≈ 4.5–5.0. Microbial growth, phenolic compounds, antioxidant, and antidiabetic activities were evaluated. In vitro digestion followed by in vitro faecal fermentation were used to study the impact of the fermented plant-based functional beverage (PBFB) on the human gut microbiota. Antidiabetic activity (21% vs. 14%) and total phenolics (244 vs. 181 mg of gallic acid equivalents/kg PBFB) increased with fermentation. The digested fermented PBFB contributed to the increase, over the first 6 h, of the Bifidobacterium’s 16S rRNA gene copy numbers, concomitant with significant release of the acetic, propionic, and butyric short chain fatty acids, and also lactic acid. The novel PBFB has been shown to have antidiabetic potential and bifidogenic effects, and consequently its consumption might positively impact blood glucose levels and the human gut microbiota. Full article

The use of lactic acid bacteria for developing functional foods is increasing for their ability to synthesize beneficial metabolites such as vitamin B (riboflavin, RF) and postbiotic compounds. Here, the spontaneous mutant FS54 B2 was isolated by treatment of the dextran-producing Weissella confusa FS54 strain with roseoflavin. FS54 B2 overproduced RF (4.9 mg/L) in synthetic medium. The FMN riboswitch is responsible for the regulation of RF biosynthesis, and sequencing of the coding DNA revealed that FS54 B2 carries the G131U mutation. FS54 B2 retained the capacity of FS54 to synthesize high levels of dextran (3.8 g/L) in synthetic medium. The fermentation capacities of the two Weissella strains was tested in commercial oat-, soy- and rice-based beverages. The best substrate for FS54 B2 was the oat-based drink, in which, after fermentation, the following were detected: RF (2.4 mg/L), dextran (5.3 mg/L), potential prebiotics (oligosaccharides (panose (5.1 g/L), isomaltose (753 mg/L) and isomaltotriose (454 mg/L)) and the antioxidant mannitol (16.3 g/L). pH-lowering ability and cell viability after one month of storage period were confirmed. As far as we know, this is the first time that an RF-overproducing W. confusa strain has been isolated, characterized and tested for its potential use in the development of functional beverages. Full article

The impact of wheat sourdough inoculated with a promising lactic acid bacterium Weissella confusa V20, isolated from a Tunisian desert plant, on the quality characteristics of sourdough and bread as well as on acrylamide formation was evaluated. W. confusa V20 sourdough (SWc) did not provide high final acidity and could effectively metabolize sucrose, resulting in significant (p < 0.05) increases in glucose (44.5%) and fructose (84.2%) levels. A substantial decrease (p < 0.05) in free asparagine was observed upon fermentation, reducing from 16 ± 0.9 mg/100 g dry weight (d.w.) in the control dough with baker’s yeast (DBB) to 9.9 ± 0.4 mg/100 g d.w. in the dough inoculated with W. confusa V20 sourdough (DWc) and to 14.2 ± 0.2 mg/100 g d.w. in the dough produced with spontaneous sourdough (DSS). To improve the texture and flavor of the bread, the sourdough process should be further optimized in a strain-specific approach. V20 sourdough was more effective in enhancing the quality of the dough and bread compared to sourdough fermented with yeast. W. confusa V20 proved to be highly effective in reducing acrylamide levels, achieving a significant 62% decrease compared to the control. Full article

Background: Weissella confusa is a member of the lactic acid bacterium group commonly found in many salt-fermented foods. Strains of W. confusa isolated from high-salinity environments have been shown to tolerate salt stress to some extent. However, the specific responses and mechanisms of W. confusa under salt stress are not fully understood. Methods: To study the effect of NaCl stress on W. confusa, growth performance and metabolite profiles of the strains were compared between a NaCl-free group and a 35% NaCl-treated group. Growth performance was assessed by measuring viable cell counts and examining the cells using scanning electron microscopy (SEM). Intracellular and extracellular metabolites were analyzed by non-targeted metabolomics based on liquid chromatography-mass spectrometry (LC-MS). Results: It was found that the viable cell count of W. confusa decreased with increasing salinity, and cells could survive even in saturated saline (35%) medium for 24 h. When exposed to 35% NaCl, W. confusa cells exhibited surface pores and protein leakage. Based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, 42 different metabolites were identified in the cells and 18 different metabolites in the culture medium. These different metabolites were mainly involved in amino acid metabolism, carbohydrate metabolism, and nucleotide metabolism. In addition, salt-exposed cells exhibited higher levels of intracellular ectoine and lactose, whose precursors, such as aspartate, L-2,4-diaminobutanoate, and galactinol, were reduced in the culture medium. Conclusions: This study provides insight into the metabolic responses of W. confusa under salt stress, revealing its ability to maintain viability and alter metabolism in response to high NaCl concentrations. Key metabolites such as ectoine and lactose, as well as changes in amino acid and nucleotide metabolism, may contribute to its tolerance to salt. These findings may improve our understanding of the bacterium’s survival mechanisms and have potential applications in food fermentation and biotechnology. Full article