ABSTRACT Lactococcus lactis is one of the most important and safe microorganisms used in the dairy industry. Previously, we orally fed cholesterol-fed rabbits with recombinant Ling Zhi 8 (LZ8) protein from L. lactis NZ3900/pNZ8149 and showed anti-inflammatory effects during the development of fatty liver and atheroma. In order to generate a clinically effective oral immunotherapy for the treatment of allergy, L. lactis clones for Der p 2, Per a 2, and Cla c 14 were introduced into L. lactis NZ3900/pNZ8149 to obtain recombinant allergen-based vaccines. In this study, we developed a triple-antigen vaccine formulation, Lactis- IL-1Ra, Lactis-LZ8, Lactis-Triple, and evaluated their preclinical safety in rabbits by oral administration with repeated doses for 90 days. All of the rabbits survived the challenge without any adverse clinical signs or abnormal changes. A notable advantage of this vaccine is that it can be given orally, and thus self-administration at home would be feasible.

ABSTRACT This study aimed to investigate the effect of mutating the consensus pentapeptide on the enzymatic properties and structural characteristics of Bacillus licheniformis lipase. Site-directed mutagenesis was used to construct mutants and then expressed in Escherichia coli BL21. After purification and enzyme activity analysis, only A75C and A75G retained activity. Compared to the wild-type lipase and A75G, the A75C showed higher thermostability at 40°C and better alkali resistance in pH 9.0–10.0 after incubation for 1 h. The kinetic parameters, structural characteristics and surface hydrophobicity of the lipases were determined. The results indicated that the secondary structure was hardly changed, while mutants exhibited higher activity, thermostability and hydrophobicity. Finally, the reasons for the increased enzyme activity were conducted through molecular dynamics simulation. The strategy of mutating the first residue of the lipase consensus pentapeptide may provide new insights into the enzyme engineering for industrial applications.

ABSTRACT Isoflavones provide multiple health benefits, such as the potential for prevention of cancer and osteoporosis. Isoflavones are naturally present as β-glucosides, rendering them unavailable for uptake in the human gut. In the present study, an attempt was made to understand the mechanism of β-glucoside hydrolysis by probiotic microbes. Six major probiotic-type strains were screened for β-glucosidase activity, and two annotated β-glucosidase genes were cloned and characterized from L. acidophilus. These proteins were more active on phosphorylated pNPG than on pNPG, indicating a Phosphoenolpyruvate (PEP)-dependent pathway involving phosphoglucosidase for the uptake and metabolism of β-glucosides such as isoflavones. The screening of these strains for the bioconversion of isoflavones showed above 90% isoflavone glucoside hydrolysis for four strains, with L. rhamnosus showing the highest hydrolysis. To the best of our knowledge, this is the first report comparing glucoside hydrolysis by whole bacterial cells with cell extracts and purified candidate proteins.

ABSTRACT Finger millet, kodo millet, and rice bran were chemo-enzymatically modified, and their prebiotic potential was evaluated using in-vitro human fecal batch fermentation and in-vivo feeding to mice. Modified cereal bran (mCB) from finger millet, kodo millet, and rice bran contained 30%, 17%, and 24% higher content of dietary fiber compared to their respective native bran. Tannin, flavonoids, polyphenols, and phytate content were reduced in the mCBs. Fecal batch fermentation with mCBs enhanced the short-chain fatty acid levels and the abundance of selected gut bacteria such as Bifidobacteria, Lactobacillus, and Bacteroidetes along with propionate and butyrate. In-vivo experiments showed no change in weight gain, blood glucose, and serum lipids. mCB supplementation enhanced the abundance of selected bacteria such as Bifidobacteria, Lactobacillus, and Bacteroidetes and decreased the abundance of E. coli, Klebsiella, and Clostridium. These findings provide an insight into the functional food potential of valorized mCBs in maintaining a healthy gut environment.

ABSTRACT Soybean is a healthful legume in terms of the presence of bioactive isoflavones viz. genistein, daidzein, and glycetein apart from high protein and unsaturated fat content. Soy isoflavones have several biological activities such as anti-estrogenic, anti-oxidative, and anti-cancer properties. However, they are present in biologically inactive glycosidic forms in soybean and their biological effects are dependent on deglycosylation during soy-processing or in the human gut. In these directions, food-associated and gut microbes possessing β-glucosidases activities hold potential to enhance the nutraceutical potential of soybean products by increasing the bioavailability of isoflavones. This review focuses on β-glucosidases-active microbes, their strain and species-specific variations and its impact on isoflavone aglycone content of the soybean-based foods. Further, microbial sources for isolating the native and recombinant β-glucosidases and their varying biochemical properties, and substrate specificities are discussed. Finally, augmentation of bioactivities of soybean products by fermentation with β-glucosidases-active microbes or treatment with purified β-glucosidases is discussed.

ABSTRACT The purpose of this study was to elucidate the structural, physicochemical, prebiotic, and in-vitro digestibility properties of enzymatically modified waxy rice flour (EM_WRF). Waxy rice flour (WRF) was enzymatically modified with different concentrations of pullulanase (25, 50, and 75 NPUN per g of dry basis WRF). According to XRD analysis, the A-type XRD pattern of WRF was changed to a B+V-type XRD pattern by pullulanase treatment. In the in-vitro starch digestibility study, it was found that resistant starch content (30.12–34.53%) of EM_WRF were significantly higher than that of WRF (17.34%). After fermentation of EM_WRF for 24 h, the total viable counts of L. acidophilus ATCC 4356 and L. rhamnosus ATCC 7469 on all EM_WRF was significantly higher than those on inulin. The results indicated that EM_WRF has a great prebiotic potential for the functional food industry.

ABSTRACT Tarhana is a fermented cereal product in which other ingredients vary depending on the traditional regional formulation. We aimed to evaluate associated relationships between metabolites and microbiota of five different Tarhana recipes belonging to Isparta, Maraş, Bursa, Kastamonu, and Uşak regions by collecting 19 samples during their fermentation process. The microbiota was investigated using metagenomics by high-throughput sequencing at species level showing Pediococcus acidilactici in Bursa, Lactiplantibacillus plantarum in Kastamonu, and Levilactobacillus namurensis and Levilactobacillus zymae in Uşak Tarhana were dominant. Also, Kluyveromyces in Isparta and Maraş, Saccharomyces in Bursa, and Issatchenkia in Kastamonu Tarhana types had the highest relative abundances. Uşak type contained the highest amounts of lactic, succinic, and acetic acids, respectively, which were also the major organic acids of all samples. Integrative analysis of multiple omics datasets revealed that Tarhana samples differing in biodiversity could be significantly clustered according to Tarhana type and production difference.

ABSTRACT This study aimed to investigate the in vitro properties of lactic acid bacteria isolated from colostrum samples of goat, sheep and cow. Four isolates of lactic acid bacteria identified through 16S rDNA sequencing were screened for probiotic potential including their enzymatic activities (hemolytic, DNase activity, API ZYM profiling and tolerance to the gastrointestinal conditions), their antimicrobial activities, their adhesion properties through biofilm formation capacity, auto-aggregation and co-aggregation with pathogens bacteria and hydrophobicity. They were also tested for their antibiotic susceptibility and antioxidant power. All the strains (ADG1b Lactobacillus gasseri, ZPana Lactiplantibacillus plantarum, S2ana Enterococcus hirae and ZGana Lactobacillus gasseri) demonstrated probiotic properties and they could resist different gastrointestinal conditions. They displayed good antimicrobial activities. Furthermore, they had high antioxidant power, although strain dependent. The results of this study showed that L. gasseri (ADG1b) is the most promising probiotic.

ABSTRACT Bambara groundnut (BG) offers great potential for sustainable food and nutritional security in the face of a growing population and changing climate. However, its utilization remains restricted by the hard-to-cook phenomenon of seed and the presence of anti-nutritional factors (ANFs). Fermentation has been reported to enhance the nutritional value and reduce ANFs in leguminous seeds. The induced fermentation technology exhibits greater control over the process parameters and ensures the fermented product’s quality, reproducibility, and safe consumption. Hence, this review highlights the importance of fermentation technology in overcoming the challenges of processing hard-to-cook BG while retaining its nutrients and flavor. This paper also reviews the food safety measure and risks of consuming fermented BG Future research on the fermented BG’s nutrient digestibility should be of concern to unlock its full potential as human food or animal feed.

ABSTRACT Tenderness is one of the most desirable meat qualities and a significant determinant of consumers’ preference. Estimating/achieving optimal tenderness are not straightforward because of their susceptibility to complex factors. Efforts toward fostering optimal tenderness in meat are called meat tenderization and can be categorized under physical, chemical, and biological approaches. While physical tenderization involves mechanically breaking the muscle myofibrillar/connective tissues, chemical techniques apply chemical/synthetic additives. Conversely, the most sustainable biological approaches use natural products (mainly proteases) to foster meat tenderness. This study presents an updated review of natural products from plants, animals, and microbes that have gained applicability as meat tenderizers. We have discussed in detail the comparative advantages and disadvantages of the different natural sources of tenderizers and presented some overarching factors that limit the widespread acceptance of natural tenderizers over synthetic chemicals. Finally, prospects for achieving natural products as a more global choice for tenderizing meat were suggested.