Search Results (69)

Miang, a traditional fermented tea produced from Camellia sinensis var. assamica, is of notable cultural and socio-economic relevance in Northern Thailand. Traditionally, the non-filamentous fungi-based process (NFP) in western Lanna uses only young tea leaves, resulting in substantial amounts of mature leaves being discarded as agricultural waste. This study aimed to utilize the mature tea leaves by adapting the filamentous fungi growth-based process (FFP) of eastern Lanna using selected tannin-tolerant microorganisms, including Aspergillus niger MLF3, Cyberlindera rhodanensis P3, and Lactiplantibacillus pentosus A14-6. Study on fermentation dynamics and bioactive compound formation based on a 2-step fermentation process: 3-day solid-state fermentation with A. niger MLF3, followed by 7-day submerged fermentation by co-culture of C. rhodaninsis P3, and L. pentosus A14-6 in 500 mL sterile distilled water at 30 °C. Increased activities of polysaccharide-degrading enzymes and organic acids were clearly observed during solid-state fermentation, while the significant changes in polyphenol, antioxidant, and reducing sugar content in cell-free supernatant (CFS) were found after submerged fermentation. The obtained CFS shows inhibitory effects of 90 ± 2.5% and 95 ± 1.8% on α-glucosidase and α-amylase, respectively. Analysis of CFS by E-tongue and E-nose clearly indicated the influence of microbial mixture on the taste and aroma of the fermented products. These results demonstrate not only a high-yielding strategy for the effective biotransformation of mature tea leaves into functional drink products but also significant implications for reducing agricultural waste. Full article

The Protected Designation of Origin (PDO) “Oliva di Gaeta” is a type of Italian fermented table olive obtained through a spontaneous fermentative process (“Itrana” method) driven by the indigenous olives microbiota. Although the use of starter cultures may improve the fermentative process and the quality of the final product, this has been poorly investigated for PDO Gaeta olives. In this study, we evaluated the use of Lactiplantibacillus pentosus O17 as a starter culture for the production of Gaeta-like olives. Three fermentations were performed: a spontaneous process (according to PDO regulation, trial A), fermentation driven by Lpb. pentosus O17 (trial B), and O17-driven fermentation combined with different brine formulation (trial C). Physicochemical properties (i.e., pH, titratable acidity, salt, and total phenolic content) and microbial population (plate counting and metataxonomy) were monitored up to 180 days. Sensory and texture profiles were evaluated in the final product. Driven fermentations (trials B and C) led faster acidification and enhanced the microbial quality of table olives without altering the organoleptic features of Gaeta-like olives. Our study suggests that the use of a starter culture and a different brining method could improve the microbiological quality of Gaeta-like olives, while preserving the traditional identity and the sensory attributes related to this PDO product. Full article

Celiac disease (CD) is an autoimmune disorder triggered by immunogenic gluten peptides that resist gastrointestinal digestion. The only current treatment is a strict gluten-free diet, which is challenging to maintain. Lactic acid bacteria (LAB) with specific proteolytic systems offer a promising strategy for gluten hydrolysis and potential reduction of immunogenicity. This study aims to isolate and characterize gluten-degrading LAB from traditional Spanish and Algerian dairy products. A total of 27 artisanal dairy samples were collected. LAB were isolated on MRS and Elliker agar. Gluten-degrading activity was screened using a well diffusion assay with cell-free supernatants and a spot assay with live cultures. Active isolates were identified by 16S rRNA gene sequencing. Out of 123 isolates, 40 (32.5%) were positive in the well assay, while 67 (54.5%) were positive in the spot assay, indicating the latter’s higher sensitivity for detecting cell-associated proteases. Halo diameters ranged from 6 to 16 mm. Algerian isolates exhibited significantly stronger activity (mean halo: 12.6 ± 2.1 mm) compared to Spanish isolates (10.2 ± 2.0 mm; p < 0.001). Molecular identification of the 32 most active isolates revealed the following dominant species: Lactiplantibacillus plantarum, L. pentosus, Levilactobacillus brevis, and Enterococcus faecium. This study confirms that artisanal dairy fermentations are rich sources of LAB with robust gluten-degrading potential. The superior activity of Lactiplantibacillus spp. aligns with their complex peptidase systems. The geographical variation highlights the influence of local fermentation practices. Selected strains represent excellent candidates for developing adjunct cultures to produce gluten-reduced foods and warrant further investigation as potential probiotics, pending safety and efficacy validation in vivo and in clinical studies. Full article

This study aims to investigate the effects of three lactic acid bacteria (LAB) strains, Lactiplantibacillus plantarum, Lactiplantibacillus pentosus and Limosilactobacillus fermentum, isolated from traditional pickles in Guizhou, on the fermentation process and microbial community dynamics of ensiled whole-plant maize, soybean, and their mixtures. The results revealed that compared to the CK group, the lactic acid levels of Lactiplantibacillus plantarum and Lactiplantibacillus pentosus were significantly increased in the treatment groups (p < 0.05), resulting in a faster pH reduction, along with decreases in ammonia nitrogen (AN) and butyric acid (BA) content. In contrast, the Limosilactobacillus fermentum treatment (p < 0.05) promoted acetic acid (AA) production and inhibited the growth of harmful microbiota in soybean silage. Notably, inoculation with all LAB strains enhanced the aerobic stability of maize silage by promoting the proliferation of Lactiplantibacillus during the later stages of fermentation, thereby sustaining a low pH and mitigating the depletion of water-soluble carbohydrates (WSC). Furthermore, all treatments accelerated silage fermentation by enhancing the LAB population and competing with yeast and Escherichia coli for available nutrients in mixed silage. These findings indicate that three LAB strains, when used as microbial additives, demonstrated potential to improve silage quality in the Karst region. Full article

Background/Objectives: Strain-level detection of bacteria is essential for applications such as diagnostics, food safety, and microbial monitoring. While 16S rRNA gene sequencing provides genus- or species-level resolution, it cannot reliably discriminate closely related strains. Whole-genome sequencing (WGS) offers high-resolution strain differentiation but remains impractical for routine detection due to cost and analytical complexity. This study aims to enable the translation of WGS data into accurate and cost-effective strain-specific PCR assays. Methods: We developed Erimin, a modular, shell-based bioinformatics pipeline for the automated identification of strain-specific genomic regions from short-read WGS data. Erimin systematically analyzes all available reference genomes for a given bacterial species in combination with sequencing data from a target strain. The workflow integrates reference-based read alignment, extraction of unmapped reads, de novo assembly, contig filtering and validation, genome annotation, and in silico PCR primer design and specificity evaluation. Results: Erimin was applied to Lactiplantibacillus pentosus whole-genome sequencing data to identify genomic regions specific to strain L33 through comparative analysis against a comprehensive set of reference genome assemblies representing multiple Lactiplantibacillus species. These regions were used for in silico PCR primer design and computational specificity assessment against non-target bacterial genomes, supporting discrimination of closely related strains. Conclusions: Erimin provides a structured computational approach for identifying strain-specific genomic regions from WGS data and for supporting the in silico design of PCR primers. This framework facilitates strain-level discrimination using targeted molecular assays. Full article

This study aims to investigate the functional and biochemical characteristics of sprouted and unsprouted red and black amaranth flours by fermentation with four probiotic strains (Lactiplantibacillus plantarum MIUG BL21, Lactiplantibacillus pentosus MIUG BL24, Lacticaseibacillus rhamnosus MIUG BL38, and Lactiplantibacillus paraplantarum MIUG BL74). Aqueous extracts from freeze-dried fermented products derived from sprouted and raw seed of two Amaranthus species (Amaranthus cruentus—red amaranth and Amaranthus hypochondriacus—black amaranth) were characterised for their acidification and phytochemical profiles by titrimetric, spectrophotometric and chromatographic methods, and their antioxidant activities by ABTS and DPPH assays. Water-soluble proteins were evaluated by SDS-PAGE analysis. Nine phenolic acids (gallic acid, protocathechic acid, syringic acid, ellagic acid, ferulic acid, cinnamic acid, caffeic acid, p-coumaric acid, and chlorogenic acid) and twelve flavonoids (epicatechin gallate, hesperitin, quercetin, apigenin, luteolin, naringenin, quercetin 3-glucoside, isorhamnetin, peonidin 3-O rutinoside, epicatechin, keracyanin, and rutin trihydrate) were identified in the extracts of amaranth samples. The titratable acidity ranged from 0.59 to 5.50 mL of 0.1 N NaOH. Total flavonoid content (TFC) varied from 1.09 to 4.67 mg CE/g DW; whereas, total phenolic content (TPC) fluctuated from 1.99 to 5.76 mg GAE/g DW. The spectrum of ABTS and DPPH values was from 17.49 to 56.82% and 0.60 to 35.50%, respectively. More biologically active compounds were found in red amaranth-based samples, both sprouted and unsprouted, compared to black amaranth-based samples. There was a moderate correlation between the TPC and the antioxidant activity. The fermentation of red amaranth with L. rhamnosus MIUG BL38 led to a global increase in the protein background intensity, consistent with protein hydrolysis. Overall, sprouting and probiotics fermentation improved the fermentative performance of the amaranth seeds, enabling their effective use as a nutritive food with potential health-promoting properties. Full article

This study reports the isolation, identification, and functional characterization of lactic acid bacteria (LAB) obtained from the endogenous fermentation of Theobroma bicolor (pataxte), an understudied Mesoamerican species with unexplored biotechnological potential. Five lactic acid bacteria strains were isolated and selected for comprehensive in vitro evaluation of their probiotic attributes. The assays included antimicrobial activity (disk diffusion and minimum inhibitory concentration), tolerance to simulated gastrointestinal conditions, and comparison of survival between non-encapsulated and bigel-encapsulated cells during digestion. All five isolates demonstrated notable antimicrobial activity against Escherichia coli ATCC 25922, Salmonella Enteritidis ATCC 13076, and Staphylococcus aureus ATCC 25923. Strain S1.B exhibited exceptional resistance to acidic pH (2.0) and bile salts, reaching 3.61 ± 0.00 log (CFU/mL) after gastrointestinal simulation. The strain was identified as Lactiplantibacillus pentosus via 16S rRNA gene sequencing, marking the first documented isolation of this species from pataxte fermentation. Bigel encapsulation markedly enhanced its survival, increasing viability to 5.08 ± 0.10 log (CFU/mL). These findings identify Lactiplantibacillus pentosus 124-2 as a potential probiotic candidate originating from pataxte fermentation and highlight bigel systems as powerful vehicles for bacterial protection. Collectively, this work expands the microbial biodiversity known in Theobroma fermentations and underscores their promise for future functional food applications. Full article

Lactic acid bacteria can colonize the gut, thereby regulating the gut microbiota and improving intestinal health. The study aimed to screen the suitable strains for Suanzhou fermentation and investigate their roles in the chicken gut in vivo. A total of 70 strains of lactic acid bacteria isolated from Suanzhou were characterized to determine their biofilm formation abilities. The strains with high-yielding biofilms were further characterized for their optimum growth temperature and pH, as well as antibacterial effects. Based on the results of biofilm formation, temperature and pH tolerance, and antibacterial effect experiments, two strains of h8-c and p15-c (Lactiplantibacillus pentosus) with high-yielding biofilms and better antibacterial effects were selected. By establishing a chick Lactobacillus feeding model and using high-throughput techniques to analyze the structure and diversity of the gut microbiota, we investigated changes in the diversity of gut bacteria, fungi, and archaea during and for three weeks after feeding with h8-c and p15-c. The results indicate that h8-c and p15-c may promote the intestinal colonization of lactobacilli, thereby balancing the gut microbiota and enhancing intestinal health in chicks. Furthermore, these strains provide excellent candidates for the industrial fermentation of Suanzhou. Full article

Sorghum (Sorghum bicolor (L.) Moench) is increasingly recognized as a sustainable crop due to its adaptability to challenging environmental conditions and its nutritional potential. The present study aimed to characterize the nutritional composition and native microbial species associated with three sorghum hybrids cultivated in Bulgaria. Crude protein was 9.37–10.42%, total carbohydrate content was between 87.4 and 89.6%, and crude fat content was in the range of 3.84–4.9%. Linoleic acid was the predominant fatty acid in all hybrids, accounting for 44.9% to 48.0% of total lipids. Quinic acid emerged as the dominant organic acid in all hybrids, with the highest concentration of 729.37 mg/100 g. The microbiological assessment focused on lactic acid bacteria (LAB) and yeasts. Microbial isolates were subjected to molecular identification through 16S rRNA gene and ITS region sequencing. The predominant LAB species included Levilactobacillus brevis, Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Pediococcus acidilactici, and Pediococcus pentosaceus, while most of the yeast isolates belonged to Saccharomyces cerevisiae. Phylogenetic analysis indicated substantial intraspecies variation, particularly within LAB strains, suggesting the presence of unique genotypic traits. These findings contribute to a better understanding of sorghum’s nutritional value and endogenous microbiota and open opportunities for developing sorghum-based functional products. Full article

In this study, the characterization, production, and application of antifungal metabolites obtained from the Levilactobacillus (L. brevis S27) and two Lactiplantibacillus (L. pentosus S42 and L. plantarum S62) strains were evaluated. The lactic acid bacteria (LAB) cells showed antifungal activity against molds. The cell-free supernatant (CFS) of Levilactobacillus and Lactiplantibacillus presented antimicrobial activity against fungi and foodborne pathogenic bacteria, and the antifungal activity was significantly (p < 0.05) higher than that of the antibacterial activity. Moreover, the antifungal metabolites were characterized as proteinaceous compounds that remained stable under both high and low temperatures and demonstrated activity across a broad pH range. Additionally, metabolite production was significantly higher (p < 0.05) at an initial pH of 5 when incubated at either 25 °C or 37 °C. All strains and their CFSs exhibited strong bio-preservative effects against Penicillium digitatum in yogurt and against Aspergillus niger on orange fruit. Consequently, these Lactobacilli strains and their antifungal metabolites represent a novel approach to biocontrol in the agri-food industry and agricultural products. Full article

The growing global population has highlighted the need to replace animal-based meat with plant-based meat (PBM) as a protein source. Using lactic acid bacteria (LAB) offers a promising and sustainable approach to prolong PBM shelf life and maintain quality comparable to non-food additives. This study investigated the potential of LAB to improve the qualities of PBM products. Three LAB strains, Lactiplantibacillus plantarum (LM), Lactiplantibacillus pentosus (LS), and Pediococcus acidilactici (PA) were selected from vegetable sources, and their effects on PBM shelf life were monitored for 21 days at 4 °C. Results showed that PBM samples treated with both Lactiplantibacillus spp. maintained consistent color properties throughout the cold storage period. Textural analysis revealed that the control samples exhibited the lowest hardness, springiness, gumminess, and chewiness, while LS-treated samples showed the highest values. Both Lactiplantibacillus spp. treated samples had pH values at less than 5, with no statistically significant differences. Volatile organic compounds were not impacted by LAB. LM-treated PBM exhibited higher amino acid content compared to LS and non-LAB-treated samples. Our findings showed that L. plantarum improved the texture and prolonged the shelf life of PBM products at 4 °C for 21 days. Results indicated that L. plantarum could be used as an alternative sustainable green biological preservative agent, serving as a clean label product. Full article

Sant’Agostino green table olives, traditionally processed in Apulia and flavoured with Foeniculum vulgare, represent a niche product whose microbial ecology remains largely unexplored. This study aimed to characterise the microbiota of the final product (both brine and fruit) after six months of storage with wild fennel. Four production batches were analysed using a combined culture-dependent and culture-independent approach. Microbiological counts revealed variable levels of aerobic mesophilic microorganisms, yeasts, lactic acid bacteria (LAB), and staphylococci, with yeasts and LAB being predominant. Ten LAB strains were identified, including Enterococcus faecium, Leuconostoc mesenteroides subsp. jonggajibkimchii, Leuconostoc mesenteroides subsp. cremoris, Leuconostoc pseudomesenteroides, Lactiplantibacillus plantarum, and Lactiplantibacillus pentosus. Yeast isolates belonged to Candida tropicalis, Torulaspora delbrueckii, and Saccharomyces cerevisiae. Amplicon sequencing (MiSeq Illumina) revealed distinct bacterial profiles between fruit and brine samples, with taxa from Actinobacteria, Bacteroidetes, Enterococcus, Lactobacillus, Leuconostoc, Alphaproteobacteria, Enterobacteriaceae, and other Gammaproteobacteria. Enterococcus and Leuconostoc were consistently detected, while Lactobacillus sensu lato appeared only in one fruit and one brine sample. These findings provide new insights into the microbial diversity of Sant’Agostino olives and contribute to the understanding of their fermentation ecology and potential for quality and safety enhancement. Full article

This study reports the biosynthesis of selenium nanoparticles (Se-NPs) using four newly isolated strains of lactic acid bacteria, molecularly identified as Lactiplantibacillus pentosus, Lactiplantibacillus plantarum, Lactiplantibacillus plantarum, and Lactobacillus acidophilus. The synthesized Se-NPs were characterized using Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), and UV-Vis Spectroscopy, and zeta potential analysis. The result revealed that their size ranged from 16 nm to 90 nm with favorable stability and purity. The Se-NPs exhibited significant antimicrobial and antibiofilm activities against certain Gram-positive, Gram-negative bacteria, and Candida albicans, particularly those produced by isolate S4, which showed the lowest MIC values and highest biofilm inhibition. Furthermore, MTT assays revealed selective cytotoxicity against the A549 cancerous lung cell line, with minimal toxicity toward normal Wi38 cells. These findings suggest that biosynthesized Se-NPs are a promising, biocompatible candidate for combating antibiotic-resistant pathogens and biofilm-associated infections. Full article

Lactiplantibacillus pentosus is a lactic acid bacterium frequently detected in various fermented foods; however, the genomic traits related to its biotechnological potential have been underexplored. In this study, 34 catalase-negative isolates were obtained from pickled mustard greens, among which strain P7 exhibited the highest exopolysaccharide (EPS) yield (781.9 ± 14.7 mg/L) and was capable of growing in a chemically defined medium lacking riboflavin. Whole-genome sequencing revealed a 3,749,478 bp circular chromosome with 46.5% G + C content and 3389 protein-coding genes. A phylogenomic analysis identified P7 as L. pentosus. Functionally, 1 mg/mL EPS extracted from P7 demonstrated strong antioxidant activity, with DPPH and hydroxyl radical scavenging capacities of 89.8 ± 4.6% and 76.5 ± 9.5%, respectively. The use of 0.2 mg/mL EPS also protected Saccharomyces cerevisiae cells from oxidative stress. A comparative genomic analysis indicated the presence of nearly complete biosynthetic pathways for riboflavin, folate, and pyridoxine. High-performance liquid chromatography (HPLC) confirmed the production of 23.8 ± 0.4 µg/mL riboflavin, 36.6 ± 0.6 µg/mL folic acid, and 0.42 ± 0.02 µg/mL pyridoxine in the culture supernatant, which have not been previously reported. Additionally, strain P7 produced 91.2 ± 12.3 g/L of lactic acid after 24 h of incubation. These results support the potential of L. pentosus P7 as a candidate for industrial applications in the production of EPS, B-group vitamins, and lactic acid. Full article

Lactiplantibacillus species have been historically used for food applications. Although several species are regarded as safe according to their regulatory status, the safety issues and functional roles of these lactic acid bacteria have been given attention. A selected Lactiplantibacillus strain TBRC 20328, with probiotic properties isolated from fermented Isan-style pork sausage (Mam), was evaluated for its safety through whole-genome sequencing and analysis using integrative bioinformatics tools. The metabolic genes were assessed through comparative genome analysis among Lactiplantibacillus species. The genome of the strain TBRC 20328 consisted of one circular chromosome (3.49 Mb) and five plasmids (totaling 0.25 Mb), encoding 3056 and 284 protein-coding genes, respectively. It exhibited an average nucleotide identity (ANI) with other Lactiplantibacillus pentosus strains of over 95%. Whole-genome analysis confirmed the absence of virulence and antimicrobial resistance genes, supporting its safety for food applications. Functional annotation revealed clusters for bacteriocins (plantaricin EF and pediocin) and polyketides, indicating potential roles in biopreservation and host interactions. Genes involved in the biosynthesis of some short-chain fatty acids and exopolysaccharides were also identified. Comparative genomic analysis across 33 other Lactiplantibacillus strains identified 2380 orthogroups, with 94 unique to the Lp. pentosus group. These included gene clusters involved in malonate decarboxylation, leucine biosynthesis, and 5-oxoprolinase activity. Such distinct genomic features emphasize the sustainable biotechnological potential and safety of Lp. pentosus TBRC 23028. Together, the findings highlight its promise as a safe and functional probiotic candidate with broad applications in functional food development and precision fermentation technologies. Full article