Microbial exopolysaccharides (EPSs), having great structural diversity, have gained tremendous interest for their prebiotic effects. In the present study, mice models were used to investigate if microbial dextran and inulin-type EPSs could also play role in the modulation of microbiomics and metabolomics by improving certain biochemical parameters, such as blood cholesterol and glucose levels and weight gain. Feeding the mice for 21 days on EPS-supplemented feed resulted in only 7.6 ± 0.8% weight gain in the inulin-fed mice group, while the dextran-fed group also showed a low weight gain trend as compared to the control group. Blood glucose levels of the dextran- and inulin-fed groups did not change significantly in comparison with the control where it increased by 22 ± 5%. Moreover, the dextran and inulin exerted pronounced hypocholesterolemic effects by reducing the serum cholesterol levels by 23% and 13%, respectively. The control group was found to be mainly populated with Enterococcus faecalis, Staphylococcus gallinarum, Mammaliicoccus lentus and Klebsiella aerogenes. The colonization of E. faecalis was inhibited by 59–65% while the intestinal release of Escherichia fergusonii was increased by 85–95% in the EPS-supplemented groups, respectively, along with the complete inhibition of growth of other enteropathogens. Additionally, higher populations of lactic acid bacteria were detected in the intestine of EPS-fed mice as compared to controls.

The thermodynamic and kinetic properties of solids state raw starch digesting alpha amylase from newly isolatedBacillus licheniformisRT7PE1 strain were studied. The kinetic valuesQp,Yp/s,Yp/X, andqpwere proved to be best with 15% wheat bran. The molecular weight of purified enzyme was 112 kDa. The apparentKmandVmaxvalues for starch were 3.4 mg mL⁻¹and 19.5 IU mg⁻¹protein, respectively. The optimum temperature and pH forα-amylase were 55°C, 9.8. The half-life of enzyme at 95°C was 17h. The activation and denaturation activation energies were 45.2 and 41.2 kJ mol⁻¹, respectively. Both enthalpies (ΔH∗) and entropies of activation (ΔS∗) for denaturation ofα-amylase were lower than those reported for other thermostableα-amylases.

Apilactobacillus spp. are classified as obligate fructophilic lactic acid bacteria (FLAB) that inhabit fructose-rich niches such as honeybee gut. Lactic acid bacteria are an important component of the gut microbiome and play a crucial role in maintaining gut health. In this study, a new FLAB strain HBW1, capable of producing glucan-type exopolysaccharide, was isolated from giant honeybee (Apis dorsata) gut and subjected to whole genome sequencing (WHS) to determine its health-beneficial traits. The genome size of the isolate was 1.49 Mb with a GC content of 37.2%. For species level identity, 16S rDNA sequence similarity, genome to genome distance calculator (dDDH), and average nucleotide identity (ANI) values were calculated. Phylogenetic analysis showed that the isolate HBW1 belongs to the Apilactobacillus genus. The dDDH and ANI values in comparison with closely clustered Apilactobacillus kunkeei species were 52% and 93.10%, respectively. Based on these values, we concluded that HBW1 is a novel species of Apilactobacillus, and we propose the name Apilactobacillus waqarii HBW1 for it. Further, WHS data mining of HBW1 revealed that it harbors two glucosyltransferase genes for prebiotic glucan-type exopolysaccharide synthesis. Moreover, chaperon (clp) and methionine sulfoxide reductase (msrA, msrB, and msrC) genes as well as nutritional marker genes for folic acid (folD) and riboflavin biosynthesis (rib operon), important for conferring probiotic properties, were also detected. Occurrence of these genetic traits make HBW1 an excellent candidate for application to improve gut function.

Actinomycetes, most notably the genus Streptomyces, have great importance due to their role in the discovery of new natural products, especially for finding antimicrobial secondary metabolites that are useful in the medicinal science and biotechnology industries. In the current study, a genome-based evaluation of Streptomyces sp. isolate BR123 was analyzed to determine its biosynthetic potential, based on its in vitro antimicrobial activity against a broad range of microbial pathogens, including gram-positive and gram-negative bacteria and fungi. A draft genome sequence of 8.15 Mb of Streptomyces sp. isolate BR123 was attained, containing a GC content of 72.63% and 8103 protein coding genes. Many antimicrobial, antiparasitic, and anticancerous compounds were detected by the presence of multiple biosynthetic gene clusters, which was predicted by in silico analysis. A novel metabolite with a molecular mass of 1271.7773 in positive ion mode was detected through a high-performance liquid chromatography linked with mass spectrometry (HPLC-MS) analysis. In addition, another compound, meridamycin, was also identified through a HPLC-MS analysis. The current study reveals the biosynthetic potential of Streptomyces sp. isolate BR123, with respect to the synthesis of bioactive secondary metabolites through genomic and spectrometric analysis. Moreover, the comparative genome study compared the isolate BR123 with other Streptomyces strains, which may expand the knowledge concerning the mechanism involved in novel antimicrobial metabolite synthesis.

The major challenge in large‐scale industrial use of lipopeptide surfactin is the low yield by indigenous bacterial strains and the higher cost of its production that have been proved as a limiting factor in commercial applications. Therefore, there is an urgent demand for high‐yielding strains that can be achieved through strain improvement. A first report on the use of a combination of UV and gamma‐irradiation mutagenesis for the development of surfactin hyperproducing mutants of Bacillus spp. proved to be significant and resulted in a twofold enhancement in surfactin yield. The mutant was able to grow and produce surfactin on all the tested carbon and nitrogen sources, while 2% glycerol favored maximum surfactin yield (1.62 g/L) as compared to the wild‐type strain that showed a maximum 0.85 g/L surfactin yield at 3% sucrose. Additionally, the mutant exhibited a good yield of pure surfactin, that is, 1.55 g/L as compared to the wild strain (0.411 g/L) by using corn steep liquor as the main component of the fermentation medium. The study concluded overall a threefold enhancement in the relative abundance of purified surfactin and its isoforms detected by matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) analysis in mutant strain AF‐UV γ 2500.