This study examined antimicrobial resistance (AMR) in Streptococcus thermophilus and Lactobacillus spp. isolated from traditional Indian Dahi. From 96 traditional Dahi samples, 104 S. thermophilus and 100 Lactobacillus isolates were tested for antibiotic susceptibility. S. thermophilus showed predominant resistance to nalidixic acid and oxacillin, with additional resistance to clindamycin, trimethoprim, ofloxacin, co-trimoxazole, erythromycin, cefuroxime, and cefepime. Lactobacillus isolates were highly resistant to nalidixic acid (97%), norfloxacin, and ofloxacin, followed by trimethoprim, co-trimoxazole, teicoplanin, oxacillin, amikacin, and vancomycin. Multiple antibiotic resistance index ranged from 0.07-0.38 in S. thermophilus and 0.07-0.45 in Lactobacillus. Thirteen S. thermophilus isolates were extended-spectrum beta-lactamase producers harboring blaTEM, with high MIC cutoffs against cefepime and cefotaxime. Macrolide resistance genes were found in S. thermophilus, aminoglycoside resistance genes in Lactobacillus, and the multidrug transporter gene (emeA) in 16 S. thermophilus strains. No mobile genetic elements were detected. These findings highlight AMR in traditional fermented milk bacteria, underscoring food-chain risks.
Hepatocyte-specific Yap1 knockout mice more susceptible to liver inflammation. This study investigated the effect of Lycium barbarum (wolfberry) on the bacterial community structure of knockout mice and its role as a potential prebiotic candidate. Mice with hepatocyte-specific Yap1 knockout exhibited a reduction in A. muciniphila colonization. Wolfberry augmented the relative abundance of Verrucomicrobia as determined by 16S rRNA analysis. Moreover, wolfberry enhanced the composition of the intestinal microbiota in mice and boosted the relative abundance of Akkermansia, Alistipes_A, and Odoribacter. Interestingly, Yap1 knockout mice during wolfberry intervention did not affect the tight connection of the intestine in mice. Nevertheless, wolfberry did not decrease the levels of aspartate transaminase (AST), alanine transaminase (ALT), and total bile acid (TBA) in mice. Therefore, short-term intervention with wolfberry did not improve liver damage in knockout mice.
Mam is a naturally fermented aquatic product from Vietnam that contains diverse lactic acid bacteria (LAB) communities. This study characterized and selected proteolytic LAB with probiotic potential isolated from four Mam sources. Among the 42 isolates, 26 were LAB, and 17 exhibited proteolytic activity (2.69-19.63 U/mg), classified into low, medium, and high groups using K-means clustering. Four promising proteolytic LABs were identified: Lactiplantibacillus pentosus S02, Lp. plantarum S12, Lp. plantarum T06, and Companilactobacillus futsaii T21. They were non-hemolytic and showed no irregular antibiotic resistance. Lp. plantarum T06 demonstrated the best bile salt tolerance (52.22% survival after 3 h), whereas Lp. plantarum S12 exhibited the best antibacterial activity against Bacillus cereus (25.07 mm). They inhibited even Gram-negative pathogens. Overall, the selected proteolytic LAB, highlighted as Lp. plantarum T06, exhibited desirable safety and probiotic properties, suggesting their potential as probiotic starters or for bioactive compound production after more in-depth safety evaluations.
Gray mold presents a significant threat to the postharvest preservation of fruits. Trehalose can inhibit the growth and reproduction of pathogenic fungi while enhancing the disease resistance of postharvest fruits. In this study, treatment with trehalose resulted in a significant reduction in the disease index, fruit rot rate, and weight loss rate. Through comparative omics analyses, we identified 2201 differentially expressed genes (DEGs) and 383 differentially expressed metabolites (DEMs). Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed that most DEGs were involved in plant hormone signal transduction, amino acid biosynthesis, and ABC transporters pathways. Additionally, genes related to defense mechanisms and their biosynthetic pathways exhibited higher expression levels. These findings suggest that trehalose can induce the expression of endogenous disease resistance signaling pathways in fruits, thereby enhancing their resistance to gray mold.
This study aimed to isolate and characterize collagenolytic bacteria from marine sediment using fish waste as a substrate. Collagenase-producing bacteria were obtained by serial dilution (up to 10(-6)) and spread plate methods. Among 15 isolates, one strain showed the highest collagen degradation activity, indicating strong potential for fish by-product utilization. Cultural, morphological, and 16S rRNA analyses identified the isolate as Bacillus subtilis. The 16S rRNA gene was sequenced and deposited in GenBank as Bacillus subtilis dfs3 (accession JF713459.1). Collagenase activity was confirmed by clear zones of collagen hydrolysis, and the enzyme was purified using ammonium sulfate precipitation and DEAE cellulose chromatography, achieving similar to 11-fold purification with an activity of 7200 units/mg. The purified enzyme had a molecular mass of 45 kDa. Optimal activity occurred at pH 8.0 and 60 degrees C, with good stability across pH 7.5-8.5 and 20-55 degrees C. These results demonstrate a sustainable and efficient approach for collagenase production with strong industrial potential.
Exopolysaccharides (EPS) from lactic acid bacteria are biological macromolecules with significant biological activities, including functioning as prebiotics to promote the growth of probiotics. This study isolated four lactic acid bacterial strains from kimchi and kefir, namely Lactiplantibacillus plantarum (Lac_KC), Pediococcus acidilactici (Ped_KC), Leuconostoc lactis (Leu_KF), and Weissella cibaria (Wei_KF). Ped_KC and Wei_KF exhibited good abilities to auto-aggregate and co-aggregate with E. coli. Meanwhile, Ped_KC and Lac_KC were more tolerant to simulated gastric and intestinal conditions, while the other two strains exhibited significantly lower survivability under gastric conditions. Regarding the EPS produced from these four strains, the results showed that the recovery from Leu_KF was highest (7.64 g/l). SEM also showed that EPS from Leu_KF had a distinct structure, while FT-IR and XRD showed similarities in their functional groups and amorphous structure. When using EPS as prebiotics, Ped_KC and Leu_KF showed the strongest growth-promoting ability upon EPS addition level of 0.1%.
Growing health-enhancing awareness has promoted the inclusion of fermented foods in daily diets. In this study, 850 yeasts were isolated from yak dahi and chhurpi, out of which only 15 were further screened. These isolates were identified as Yarrowia lipolytica (5), Saccharomyces cerevisiae (4), Kluyveromyces lactis (2), Kluyveromyces marxianus (1), Wickerhamomyces anomalus (1), Candida parapsilosis (1), and Candida metapsilosis (1). These isolates exhibited probiotic traits and showed no safety concern based on in-vitro safety evaluation. Further, these isolates have demonstrated cholesterol-lowering activity, antioxidant activity, anti-inflammatory activity, and antidiabetic activity relevant functional attributes. PCA biplot analysis obtained from the variance-covariance matrix at a 10k bootstrap value indicated Saccharomyces cerevisiae DUAY-53 from yak dahi and Kluyveromyces lactis CUBY-19 from yak chhurpi have the highest potential as probiotic yeast. The findings highlight fermented yak milk as a valuable reservoir of safe and robust probiotic yeasts, suitable for use in functional food development.
Postbiotics are emerging as a significant alternative to live probiotic cells, offering comparable health benefits to the host without the complications associated with live cells. The present study compared the anti-inflammatory effects of three postbiotic and probiotic Lactobacillus strains in an in vitro HT-29 (human colorectal adenocarcinoma) cell line and colitis mice. Postbiotics were prepared by heat-killing live probiotic cells. All preparations were nontoxic to HT-29 cells. In vitro, both postbiotics and probiotics significantly reduced Tumor Necrosis Factor alpha (TNF-alpha) levels in a strain-dependent manner. In vivo, both forms alleviated colonic inflammation, with postbiotic LGG showing the greatest improvement in histology and intestinal permeability. Furthermore, Myeloperoxidase activity supported these anti-inflammatory effects. Cytokine analysis also showed that live MTCC5690 and postbiotic MTCC5689 significantly reduced TNF-alpha secretion, while live LGG and MTCC5689 increased Interleukin-10 levels. Overall, postbiotics were as effective as probiotics in reducing inflammation, with their efficacy varying by strain.
Ibuprofen (IBU), a commonly prescribed non-steroidal anti-inflammatory drug (NSAID), is associated with gastric and hepatic side effects mediated by oxidative stress and inflammation. This study investigated the protective role of probiotic-fermented milk against IBU-induced toxicity in Wistar rats. Animals were pretreated orally for seven days with fermented milk (5 mL/kg) or omeprazole (20 mg/kg) before a single IBU administration (200 mg/kg). Fermented milk produced a strong gastroprotective effect (86.85%), reflected by elevated gastric mucus secretion and pH, and reduced gastric juice volume and peptic activity, leading to decreased ulcer formation. It also attenuated oxidative stress and inflammation by lowering malondialdehyde (MDA), nitric oxide (NO), and myeloperoxidase (MPO) while boosting antioxidant defenses, including catalase (CAT), superoxide dismutase (SOD), and glutathione (GSH), in gastric and hepatic tissues. Histopathological analysis confirmed preserved tissue architecture. Collectively, probiotic-fermented milk exerted gastroprotective and hepatoprotective effects, highlighting its promise as a functional food for mitigating NSAID-induced toxicity.
This study developed a new probiotic Zabado with upgraded quality and functional characteristics. The isolate from honey was identified as Bacillus coagulans, which forms prebiotic levan. The anti-ulcerative colitis properties of Zabado (T1) by itself, in combination with the prebiotic levan (T2), Lactobacillus as a probiotic (T3), in combination with all (T4), and in combination with sulfasalazine (T5) were assessed. This was accomplished by employing an acetic acid-induced ulcerative lesion model in rats. T1 and T2 showed a significant reduction in the formation of ulcers along with a restricted inflammatory response in the mucosa and submucosa. Zabado with levan (T2) recorded the highest protective effect, where the lowest lesion score was recorded. In all treatment groups, the COX2 expression decreased significantly in T1 and T2 treatments. In certain crypts, T3, T4, and T5 treatments showed a considerable degree of necrosis. Mucosa and submucosa also showed a moderate degree of inflammatory reaction.
This study evaluated Lactobacillus brevis QD-1, isolated from kombucha, as a starter culture for soy yogurt production. Genome analysis revealed complete pathways for carbohydrate metabolism and exopolysaccharide synthesis. This strain demonstrated the ability to ferment soymilk, achieving rapid growth, and reducing the pH to below 4.5 within 8 h. L. brevis QD-1 enhanced soy protein hydrolysis, improving texture and yielding significantly higher polyphenol content, antioxidant activity, and antimicrobial efficacy compared to L. rhamnosus ATCC 9595 (p < 0.05). In silico analyses confirmed the absence of virulence factors and antibiotic-resistance genes. Additionally, this strain revealed probiotic potential, including high survival under simulated gastrointestinal conditions, notable hydrophobicity, and co-aggregation capacity with pathogens, suggesting effective intestinal colonization. These findings identify L. brevis QD-1 as a valuable candidate for commercial plant-based yogurt production, offering a probiotic option that aligns with vegetarian preferences while providing health benefits.
In view of the paucity of studies on Amaranthus-derived iron-chelating peptides (ICP) and the grain's exceptional protein content, this study predicted ICP from Amaranthus grains that enhance iron solubility and absorption. The methodology entailed in silico retrieval of human transferrin structure (Tf) and Amaranthus globulin protein sequence, in silico digestion of globulin protein and screening of ICP, and prediction of the binding affinity of Tf and ferrous (Fe2+) complex with the peptides via biomolecular docking and molecular dynamics simulations (MDS). In silico evaluation of pharmacokinetics, drug-likeness, toxicity, allergenicity, and solubility profiles was performed for the predicted peptides. Docking analyses revealed good Tf binding affinity of peptides "AGR" and "AIVK" (-116.431 and -110.11, respectively), which were validated by another docking server (-4.377 and -5.586 kcal/mol, respectively). The docking scores of "AGR" and "AIVK" with Fe2+ were -0.624 and -0.634, respectively. The MDS results indicated stable complexes (AGR-Tf, AIVK-Tf, AGR-Fe2+, and AIVK-Fe2+), without notable structural deviations. Further, "AGR" and "AIVK" exhibited favourable drug-likeness, non-toxicity, non-allergenicity, and good solubility. The present bioinformatic findings may guide the development of iron absorption-enhancing nutraceuticals and functional foods.
Fermentation of cheese whey with Lactobacillus helveticus MTCC 5463 (GQ253959) culture was conducted for different time intervals (0, 12, 24, 36, and 48 h) at 37 degrees C for the evaluation of antidiabetic and antioxidative activities. The inhibition levels of alpha-glucosidase, alpha-amylase, and lipase, along with antioxidative activity, were recorded at 65.39%, 67.86, 63.38%, and 64.82%, respectively. The anti-inflammatory effects of fermented cheese whey on LPS-induced RAW 264.7 macrophage cells, were evaluated at concentrations of 0.5, 1, 2, 4, 6, and 8 mg/mL. The antidiabetic and antioxidative activities of fermented cheese whey fractions, including 3 kDa and 10 kDa permeates and retentates, were also assessed. Among all the fractions, the 10 kDa retentate showed the strongest ABTS radical scavenging activity and antidiabetic activities than other samples. Molecular docking of the peptides (ALCSEKLDQWLCEK, DDQNPHSSNICNISCDK, SKSSMFQNRTLK, VGINYWLAHK, and LDQWLCEK) using HADDOCK 2.4 webserver was also analysed.
The 42 kDa chitinase of T. asperellum SH16 has been regarded with considerable interest in promising biotechnological applications due to its antifungal activities. However, poor thermostability limits most practical applications. This study investigated the expression of various 42 kDa chitinase mutants in E. coli. Findings indicate that the recombinant chitinase I168L mutant demonstrated markedly improved thermostability compared to the native enzyme, retaining substantial activity even at elevated temperatures. Additionally, both in vitro and in vivo antifungal tests showed that the I168L mutant exhibited a greater inhibitory effect on the growth of Colletotrichum siamense strains, which are responsible for anthracnose in chili fruits, when compared to the native chitinase at 35 degrees C. This mutant can prevent fungal infection for up to four days following pretreatment with 80 units of I168L. These findings highlight the potential of the I168L mutant as a biocontrol agent against anthracnose diseases caused by Colletotrichum species in fruits.
Microbial exopolysaccharides (EPS) extracted from probiotic microorganisms have recently garnered considerable attention due to their wide applicability in food and pharmaceutical industries. EPS have gained attention as they are nontoxic, biocompatible and biodegradable. In this study, eight potential probiotic isolates have been isolated from traditional fermented bamboo shoots of North East India. Of the eight isolates, the isolate identified as Bacillus subtilis BB2 produced the highest amount of EPS. The monosaccharide composition analysis of the extracted EPS revealed fructose as its main component. The FT-IR spectrum identified functional groups present in the extracted EPS. Thermo gravimetric and differential scanning calorimetric analysis revealed that the EPS remained stable up to 200 degrees C. It also exhibited significant free-radical-scavenging activity in vitro. Also, extracted EPS showed antibiofilm activity against selected bacterial pathogens. These findings indicate that the EPS produced from probiotic Bacillus subtilis BB2 hold promising potential as a natural alternative for food and wider industrial applications.
The aim of this study was to evaluate the possibility of improving the intestinal environment by reducing intestinal pathogens, Staphylococcus aureus and Escherichia coli, using the three Levilactobacillus brevis strains (L. brevis KU202399, L. brevis B151, and L. brevis KU15006) isolated from kimchi. We confirmed the characteristics of the probiotics and the safety of the L. brevis strains. Also, we examined the antibacterial effects, cell surface properties, anti-adhesion ability, and expression of antibiotic resistance and toxicity genes. L. brevis KU202399 exhibited the highest antibacterial activity; L. brevis KU202399 exhibited high cell surface hydrophobicity and decreased adhesion ability of pathogens to intestinal cells. Real-time polymerase-chain reaction results showed significant downregulated expression of antibiotic resistance and toxicity-related gene treatment with L. brevis KU202399. L. brevis KU202399 modulated human fecal microbiota by increasing beneficial bacteria and reducing pathogens. Taken together, our results suggest that L. brevis KU202399 is beneficial in food and probiotic industries.
The study evaluated the prebiotic potential of polyphenols from finger millet seed coat (FMSC) on lactic acid bacteria (LAB) and in turn the biotransformation of polyphenols by the action of probiotic bacteria. In vitro fermentation studies in terms of growth kinetics of LAB, prebiotic activity score (PAS), production of short chain fatty acids (SCFAs) and the changes in phenolic contents during fermentation were assessed by GC-MS and HPLC. FMSC polyphenols were efficiently utilized by the probiotic strains evident from the maximal growth rate in the logarithmic phase, among the strains, L. plantarum showed highest growth. A sharp drop in pH was recorded, a characteristic feature of LAB. SCFAs were produced in varying quantities. Phenolic monomers and aglycones appeared after probiotic fermentation. The study substantiates the bi-directional metabolism of FMSC polyphenols and LAB, which paves way for the development of functional foods that render potential health benefits to consumers.
This study aimed to assess the technological, safety, antibiotic resistance, and antifungal properties of 35 lactic acid bacteria (LAB) from Sicilian dairy products. Sixteen Lactiplantibacillus plantarum isolates produced diacetyl, and 30 LAB isolates showed proteolytic activity, suggesting technological potential. All isolates presented weak milk acidification capacity. Aminopeptidase activity varied, with PepX (5/35) and PepN (2/35) showing better activity on Lactiplantibacillus fermentum, Lactobacillus sp. and L. plantarum strains, indicating species-specificity. None of the isolates showed hemolytic, gelatinase, DNase, or coagulase activity. Most were resistant to oxacillin, tetracycline, rifampicin, and vancomycin. Regarding antifungal activity, L. plantarum (n = 10) and Lactiplantibacillus sp. (n = 1) isolates inhibited Aspergillus niger and Penicillium chrysogenum, while L. rhamnosus (n = 5) strains were active against P. chrysogenum. Overall, Lactiplantibacillus isolates, particularly L. plantarum from donkey milk, showed promising technological traits, safety, and potential as bioprotective cultures. These findings support the search for new strains with improved characteristics and technological applications.
Glycerol has widespread applications in food, pharmaceuticals, cosmetics, and various industrial sectors. While its chemical production entails purification challenges, microbial fermentation, particularly employing Saccharomyces cerevisiae, presents a promising alternative. This study used computational techniques to identify potential inhibitors of S. cerevisiae alcohol dehydrogenase (ADH) to enhance glycerol production. High-throughput virtual screening of 190,000 natural compounds from the ZINC database revealed 116 potential ADH inhibitors. Based on in silico toxicity screening, six compounds, including a quinoline derivative, ZINC000005398892, imidazopyridoindol analog (ZINC000008918046), and four hydroxyoctahydroisoquinolin-chromenone derivatives, ZINC000002111805, ZINC000015954814, ZINC000104739723, and ZINC000002111093, were predicted to be non-mutagenic and non-carcinogenic. Molecular dynamics (MD) simulation studies confirmed the stability of these compounds during 50 ns. ZINC000002111093 was found to be the best compound in this regard. Overall, the selected natural compounds could be potential candidates to direct the metabolic pathway in S. cerevisiae toward enhanced production of glycerol instead of alcohol. Experimental studies can confirm these findings.
This study aimed to investigate the effects of a combination of Lactobacillus and inulin (LI) on memory impairment, gut microbiota composition, and metabolic profiles in APP/PS1 transgenic mice (MC). Mice treated with LI exhibited significant improvements in memory performance, along with marked reductions in A beta plaque deposition, neuroinflammation, and oxidative stress levels. Treatment with LI significantly increased the relative abundances of unclassified_f__Lachnospiraceae, Faecalibaculum, and Blautia, while significantly reducing Candidatus_Saccharimonas. Metabolomics analysis revealed that LI treatment led to elevated levels of acetylcholine, LysoPC (17:0), and sphinganine 1-phosphate, and a significant decrease in phosphocholine level. KEGG pathway analysis indicated that glycerophospholipid and sphingolipid metabolism were likely involved. In particular, Faecalibaculum and Candidatus_Saccharimonas may improve memory by modulating glycerophospholipid and sphingolipid pathways, respectively. These findings offer novel insights into microbiota-targeted strategies for memory enhancement.
