Search Results (821)

Coffee silverskin (CS), a by-product generated during coffee roasting, contains high levels of xylan hemicellulose and protein, making it a promising substrate for functional ingredient production. This study developed an integrated bioprocess to simultaneously produce bioactive peptides and xylooligosaccharides (CS-XOS) from CS. Conventional alkaline extraction (CAE) under optimized conditions (1.0 M NaOH, 90 °C, 30 min) yielded 80.64 mg of protein per gram of CS and rendered the solid residue suitable for XOS production. Enzymatic hydrolysis of the extracted protein using protease_SE5 generated low-molecular-weight peptides (0.302 ± 0.01 mg/mL), including FLGY, FYDTYY, and FDYGKY. These peptides were non-toxic, exhibited in vitro antioxidant activity (0–50%), and showed ACE-inhibitory activities of 60%, 26%, and 79%, and DPP-IV-inhibitory activities of 19%, 18%, and 0%, respectively. Concurrently, the alkaline-treated CS solid residue (ACSS) was hydrolyzed using recombinant endo-xylanase, yielding 52.5 ± 0.08 mg of CS-XOS per gram of ACSS. The CS-XOS exhibited prebiotic effects by enhancing the growth of probiotic lactic acid bacteria (μ_max 0.100–0.122 h⁻¹), comparable to commercial XOS. This integrated bioprocess eliminates the need for separate processing lines, enhances resource efficiency, and provides a sustainable strategy for valorizing agro-industrial waste. The co-produced peptides and CS-XOS offer significant potential as functional food ingredients and nutraceuticals. Full article

Lactic acid bacteria (LAB) are central to food, feed, and health biotechnology, yet their genomes have long resisted rapid, precise manipulation. This review charts the evolution of LAB genome-editing strategies from labor-intensive RecA-dependent double-crossovers to state-of-the-art CRISPR and CRISPR-associated transposase systems. Native homologous recombination, transposon mutagenesis, and phage-derived recombineering opened the door to targeted gene disruption, but low efficiencies and marker footprints limited throughput. Recent phage RecT/RecE-mediated recombineering and CRISPR/Cas counter-selection now enable scar-less point edits, seamless deletions, and multi-kilobase insertions at efficiencies approaching model organisms. Endogenous Cas9 systems, dCas-based CRISPR interference, and CRISPR-guided transposases further extend the toolbox, allowing multiplex knockouts, precise single-base mutations, conditional knockdowns, and payloads up to 10 kb. The remaining hurdles include strain-specific barriers, reliance on selection markers for large edits, and the limited host-range of recombinases. Nevertheless, convergence of phage enzymes, CRISPR counter-selection and high-throughput oligo recombineering is rapidly transforming LAB into versatile chassis for cell-factory and therapeutic applications. Full article

Buffalo mozzarella cheese whey (CW) and ricotta cheese exhausted whey (RCEW) are valuable by-products of the Mozzarella di Bufala Campana PDO production chain. This study characterized their microbial communities using an integrated culture-dependent and -independent approach. Metabarcoding analysis revealed that the dominance of lactic acid bacteria (LAB), including Streptococcus thermophilus, Lactobacillus delbrueckii, and Lactobacillus helveticus, alongside diverse heat-resistant yeasts such as Cyberlindnera jadinii. Culture-based isolation identified subdominant lactic acid bacteria strains, not detected by sequencing, belonging to Leuconostoc mesenteroides, Enterococcus faecalis, and Enterococcus durans. These strains were further assessed for their probiotic potential. E. faecalis CW1 and E. durans RCEW2 showed tolerance to acidic pH, bile salts, and lysozyme, as well as a strong biofilm-forming capacity and antimicrobial activity against Bacillus cereus and Staphylococcus aureus. Moreover, bile salt resistance suggests potential functionality in cholesterol metabolism. These findings support the potential use of CW and RCEW as reservoirs of novel, autochthonous probiotic strains and underscore the value of regional dairy by-products in food biotechnology and gut health applications. Full article

In this study, 62 lactic acid bacteria (LAB) strains were isolated from raw camel milk and evaluated for their probiotic potential. The strains exhibited significant variability in their ability to withstand simulated gastrointestinal conditions. Of the isolates, only 26 survived exposure to pH 2, and just 10 were tolerant to 0.3% bile salts. Partial sequencing of the 16S rRNA gene identified all the strains as belonging to the species Enterococcus faecium. Several probiotic traits were assessed, including adhesion to gastric mucin and STC-1 intestinal epithelial cells, as well as auto-aggregation and co-aggregation capacities. Although adhesion to hydrophobic solvents such as chloroform and ethyl acetate was generally low to moderate, all the strains demonstrated strong adhesion to gastric mucin, exceeding 60% at all the growth stages. Notably, two strains—SCC1-33 and SLch6—showed particularly high adhesion to STC-1 cells, with values of 7.8 × 10³ and 4.2 × 10³ CFU/mL, respectively. The strains also exhibited promising aggregation properties, with auto-aggregation and co-aggregation ranging between 33.10% and 63.10%. Furthermore, all the isolates displayed antagonistic activity against Listeria innocua, Micrococcus luteus, and Escherichia coli. Cytotoxicity assays confirmed that none of the tested strains had harmful effects on STC-1 cells, indicating their safety and supporting their potential application as probiotics. Full article

Probiotics have been widely explored for their potential in managing hyperuricemia. However, their isolation and identification are fundamental prerequisites for practical application. In this study, 254 lactic acid bacteria (LAB) strains were isolated from Chinese sauerkraut and screened for probiotic potential based on genomic and phenotypic characteristics, as well as nucleoside-degrading activity relevant to decrease serum urate. Among them, Lactiplantibacillus plantarum (L. plantarum) F42 exhibited the highest bile salt tolerance (survivor rate: 19.46 ± 4.33%), strong adhesion to Caco-2 cells (1.89 ± 0.12%), effective nucleoside degradation (inosine: 5.46 ± 0.67 mg∙L⁻¹∙min⁻¹; guanosine: 3.84 ± 0.11 mg∙L⁻¹∙min⁻¹), and notable anti-listeria activity (inhibition zone: 6.9 ± 0.3 mm). Based on its functional profile, L. plantarum F42 was selected as a promising probiotic candidate for further investigation of its urate-lowering effects. This work provides a new insight into anti-hyperuricemia probiotic selection based on in vitro nucleoside-degrading activity. Full article

Porphyra-derived polysaccharides (PPs) are promising prebiotic candidates due to their capacity to modulate gut microbiota and promote host health. However, their interactions with and utilization by probiotic microorganisms remain unclear. In this study, the fermentability of PPs by murine-derived lactic acid bacteria (LAB) strains was investigated, with particular attention to strain-specific metabolic activity, carbohydrate utilization, and potential exopolysaccharide (EPS) production. All tested strains were capable of utilizing PPs to varying extents, with strain A10 exhibiting the highest level of carbohydrate consumption. Notably, strain A5 showed increased mannose concentrations following fermentation, suggesting the biosynthesis of mannose-rich EPSs. HPLC analysis confirmed the presence of high-molecular-weight polysaccharides ranging from 2.6 to 8.1 × 10⁵ Da, indicative of EPS production. FT-IR spectroscopy further revealed spectral features consistent with EPS structures. The antibacterial activity of postbiotic compounds produced by LAB strains fermenting PPs against Escherichia coli and Staphylococcus aureus was observed. These findings demonstrate distinct metabolic adaptations of LAB strains to PPs and emphasize their potential as prebiotic substrates. Full article

Kombucha is a fermented tea beverage of Asian origin, widely consumed due to its functional properties; yet, it typically lacks sufficient levels of probiotic micro-organisms to be classified as a probiotic product. This review analyzes the occurrence of lactic acid bacteria (LAB) in kombucha, reporting that concentrations rarely exceed 4–5 log CFU/mL and often decline during fermentation or storage. Strategies to enhance probiotic viability, including the use of robust LAB strains and encapsulation technologies, are critically evaluated. Notably, encapsulation using pea and whey protein has been shown to sustain LAB levels above 6 log CFU/mL during fermentation and up to 21 days under refrigerated storage for whey protein. Fortified kombucha beverages with probiotic strains have also been shown to possess enhanced functional and health-promoting benefits compared to traditional control samples. Despite promising approaches, inconsistencies in microbial survival and regulatory constraints remain key challenges. Future research should focus on the optimization of delivery systems for probiotic cultures, identification of kombucha-compatible LAB strains and standardized protocols to validate probiotic efficacy in real-world beverage conditions. Full article

The aim of this study was to isolate and identify lactic acid bacteria (LAB) from a traditional fermented beverage, Boza, and to conduct an in-depth study on their fermentation and probiotic properties. The fermentation (acid production rate, acid tolerance, salt tolerance, amino acid decarboxylase activity) and probiotic properties (gastrointestinal tolerance, bile salt tolerance, hydrophobicity, self-aggregation, drug resistance, bacteriostatic properties) of the 16 isolated LAB were systematically analyzed by morphological, physiological, and biochemical tests and 16S rDNA molecular biology. This analysis utilized principal component analysis (PCA) to comprehensively evaluate the biological properties of the strains. The identified LAB included Limosilactobacillus fermentum (9 strains), Levilactobacillus brevis (2 strains), Lacticaseibacillus paracasei (2 strains), and Lactobacillus helveticus (3 strains). These strains showed strong environmental adaptation at different pH (3.5) and temperature (45 °C), with different gastrointestinal colonization, tolerance, and antioxidant properties. All the strains did not show hemolytic activity and were inhibitory to Staphylococcus aureus, and showed resistance to kanamycin, gentamicin, vancomycin, and streptomycin. Based on the integrated scoring of biological properties by principal component analysis, Limosilactobacillus fermentum S4 and S6 and Levilactobacillus brevis S5 had excellent fermentation properties and tolerance and could be used as potential functional microbial resources. Full article

The exopolysaccharide (EPS) produced by Leuconostoc mesenteroides SJC113 is a glucan with α-1,6 and α-3,6 branched glycosidic linkages that may promote human health. The aim of this study was to investigate in vitro the antioxidant, cholesterol-binding, and prebiotic activities of this EPS and its effect on the gut microbiota. The EPS exhibited moderate antioxidant activity, showing free radical scavenging activity (10.94 ± 1.33%) and hydroxyl scavenging activity (6.29 ± 1.59%) at 1 mg/mL. Notably, it showed high cholesterol-binding activity, lowering cholesterol levels by 40% at 1 mg/mL EPS. Ln. mesenteroides SJC113 showed strong adhesion to mucin, and its EPS enhanced the adhesion of the probiotic Lacticaseibacillus rhamnosus GG. The application of this EPS stimulated the growth of several lactic acid bacteria (LAB) strains in vitro, indicating its potential as a prebiotic. In addition, the use of a human gastrointestinal simulator inoculated with fecal microbiota showed that the EPS favored the growth of Bifidobacterium spp. and lactobacilli while reducing Enterobacteriaceae. These results emphasize the multifunctional nature of the EPS produced by Ln. mesenteroides SJC113 with antioxidant, cholesterol-lowering, and prebiotic properties. Further research is required to investigate the specific mechanisms of action and health benefits in vivo. Full article

Roasted coffee silverskin (RCSS) is a by-product of coffee production characterized by its content of phenolic compounds, both free and bound to macromolecules. In this study, RCSS was fermented to release these compounds and consequently increase its value as a functional food ingredient. Fermentation was carried out using yeast, acetic acid bacteria, and lactic acid bacteria, either as single strains or as a designed microbial consortium. The latter included Saccharomycodes ludwigii, Gluconobacter oxydans, and Levilactobacillus brevis, mimicking a symbiotic culture of bacteria and yeast commonly used in kombucha fermentation (SCOBY). This symbiotic microbial culture consortium demonstrated notable efficacy, significantly enhancing the total phenolic content in RCSS, with values reaching 14.15 mg GAE/g as determined by the Folin–Ciocalteu assay and 7.12 mg GAE/g according to the Fast Blue BB method. Antioxidant capacity improved by approximately 28% (ABTS) and 20% (DPPH). Moreover, the fermented RCSS supported the viability of probiotic strains (Saccharomyces boulardii SB01 and Levilactobacillus brevis ŁOCK 1152) under simulated intestinal conditions. These results suggest that RCSS, particularly after fermentation with a full symbiotic microbial culture consortium, has strong potential as a clean label, zero-waste functional food ingredient. Full article

This study aimed to ferment protein-rich amaranth flour with different strains of lactic acid bacteria (LAB) and to analyse the fermented dough’s functional properties. The fermented dough analysis was conducted using titrimetric, spectrophotometric, and chromatographic methods. The antioxidant activity of the fermented doughs was evaluated using the DPPH (2,2-Diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) methods, finding ABTS radical scavenging values ranging from 26.00 ± 1.05% to 58.92 ± 6.05%, while the DPPH values ranged from 21.29 ± 0.83% to 28.24 ± 5.48%. By RP-HPLC (Reversed Phase-High Performance Liquid Chromatography) characterisation, several phenolic acids and flavonoids were identified and quantified. Among these compounds, epigallocatechin was the most abundant, with the highest concentration recorded at 7789.88 ± 17.0 ng/µL in the control sample. This was followed by a 6942.47 ± 5.632 ng/µL concentration in the dough fermented with Lacticaseibacillus rhamnosus MIUG BL38 strain and 4983.16 ± 7.29 ng/µL in the dough fermented with Lactiplantibacillus pentosus MIUG BL24 strain. These two LAB strains (Lc. rhamnosus MIUG BL38 and Lp. pentosus MIUG BL24), with probiotic properties previously demonstrated, were selected based on their acidification potential, antioxidant activity, and bioactivity for future optimisation studies. Lactic acid fermentation significantly enhances bioactive characteristics of the amaranth flour, enabling the design of diverse gluten-free products with increased functional properties based on the attributes induced by the prebiotic, probiotic and postbiotic contents (tribiotics). Full article

The purpose of this study was to determine the impact of blanching various onion (Allium cepa L.) varieties on the process of lactic fermentation by probiotic strain Levilactobacillus brevis ŁOCK 0944. The materials for the research were twelve varieties of yellow onion: Venecia, Moondance, Sedona, Alonso, Hysky, Centro, Dormo, Hypark, Hybelle, Armstrong, EXP 2236, and Hysinger. We also studied the resulting changes in bioactive compound content. Acidic bacterial metabolites, the lactic acid bacteria count, and the polyphenol and carbohydrate contents were assessed in both raw onions and onions blanched at 60 °C, before and after fermentation. Onion varieties that showed morphological changes after blanching (Hysky, Centro, Dormo) demonstrated better growth of L. brevis and higher lactic acid production. Blanching loosened the tissue structure, reducing the carbohydrate content in the blanched and fermented onions, particularly Alonso, Centro, Dormo, and Hypark varieties. Although the combined process reduced the polyphenol content, four varieties showed no statistically significant differences, indicating variety-specific responses. The varying susceptibility of onion varieties to thermal treatment highlights the importance of selecting the appropriate variety for further processing. Full article

CRISPR technology, which is derived from the bacterial adaptive immune system, has transformed traditional genetic engineering techniques, made strain engineering significantly easier, and become a very versatile genome editing system that allows for precise, programmable modifications to a wide range of microbial genomes. The economies of fermentation-based manufacturing are changing because of its quick acceptance in both academic and industry labs. CRISPR processes have been used to modify industrially significant bacteria, including the lactic acid producers, Clostridium spp., Escherichia coli, and Corynebacterium glutamicum, in order to increase the yields of bioethanol, butanol, succinic acid, acetone, and polyhydroxyalkanoate precursors. CRISPR-mediated promoter engineering and single-step multiplex editing have improved inhibitor tolerance, raised ethanol titers, and allowed for the de novo synthesis of terpenoids, flavonoids, and recombinant vaccines in yeasts, especially Saccharomyces cerevisiae and emerging non-conventional species. While enzyme and biopharmaceutical manufacturing use CRISPR for quick strain optimization and glyco-engineering, food and beverage fermentations benefit from starter-culture customization for aroma, texture, and probiotic functionality. Off-target effects, cytotoxicity linked to Cas9, inefficient delivery in specific microorganisms, and regulatory ambiguities in commercial fermentation settings are some of the main challenges. This review provides an industry-specific summary of CRISPR–Cas9 applications in microbial fermentation and highlights technical developments, persisting challenges, and industrial advancements. Full article

Gamma-aminobutyric acid (GABA) is a non-protein amino acid playing a significant role in the central nervous system and the gut–brain axis. This study investigated the potential to produce GABA by lactic acid bacteria (LAB) isolated from different varieties of organic tomatoes. The isolated LAB were taxonomically identified by 16S rRNA gene sequencing, the presence of the gadB gene (glutamate decarboxylase) was detected, and GABA production was quantified using HPLC. Levilactobacillus brevis CRAI showed the highest GABA production under optimised fermentation conditions with 4% monosodium glutamate (MSG). The genome sequencing of L. brevis CRAI revealed the presence of gadA and gadB isoforms and assessed the strain’s safety profile. The gene expression analysis revealed that the gadA and gadB genes were upregulated in the presence of 4% MSG. The probiotic potential of L. brevis CRAI was also assessed by functional assays. The strain showed strong antimicrobial activity against representative enteropathogens, i.e., Escherichia coli ETEC, Salmonella choleraesuis, and Yersinia enterocolitica, and anti-inflammatory effect, reducing nitric oxide production in LPS-stimulated RAW264.7 macrophages. In addition, its ability to adhere to intestinal epithelial Caco-2 cells was demonstrated. These results highlight L. brevis CRAI as a promising candidate for the development of GABA-enriched functional foods or probiotic supplements with the perspective to modulate the gut-brain axis. 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