Saccharomyces boulardii is a unique species of yeast previously characterized as a probiotic strain (CNCM I-745) among a few probiotic yeasts reported to date. Inulin is one of the most common prebiotics that exhibit twisted hydrocolloidal properties in dairy products. The present study was designed to develop a synbiotic yogurt by incorporation of S. boulardii and inulin at 1%, 1.5%, and 2% (w/v), comparing with the probiotic and control plain yogurts. Microrheological, microstructural, microbiological, sensory properties, and volatile compounds of the yogurt samples were evaluated. Microrheological analysis showed that addition of inulin to yogurt slightly reduced the values of G′ and G″, while solid–liquid balance (SLB) values confirmed more solid properties of the synbiotic yogurt (0.582~0.595) than the plain yogurt (0.503~0.518). A total of 18 volatile compounds were identified in the synbiotic yogurt, while only five and six compounds were identified in plain and probiotic yogurts, respectively. Physiochemical parameters such as pH, acidity, and protein content were in the normal range (as with the control), while fat content in the synbiotic yogurt decreased significantly. Addition of 1% inulin not only reduced syneresis but also maintained viability of S. boulardii after 28 days of storage. Microstructural and microrheological studies confirmed the dense, compressed, homogeneous structure of the synbiotic yogurt. Thus, addition of inulin improved the textural and sensory properties of the synbiotic yogurt, as well as survival of S. boulardii with viable count above 6.0 log CFU/g in yogurt, as generally required for probiotics. Therefore, novel synbiotic yogurt with desirable quality was developed as an effective carrier for delivery of the probiotic yeast exerting its beneficial health effects.

The widespread and indiscriminate use of broad-spectrum antibiotics leads to microbial resistance, which causes major problems in the treatment of infectious diseases. However, advances in nanotechnology have opened up new domains for the synthesis and use of nanoparticles against multidrug-resistant pathogens. The traditional approaches for nanoparticle synthesis are not only expensive, laborious, and hazardous but also have various limitations. Therefore, new biological approaches are being designed to synthesize economical and environmentally friendly nanoparticles with enhanced antimicrobial activity. The current study focuses on the isolation, identification, and screening of metallotolerant fungal strains for the production of silver nanoparticles, using antimicrobial activity analysis and the characterization of biologically synthesized silver nanoparticles by X-ray diffraction (XRD) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). In total, 11 fungal isolates were isolated and screened for the synthesis of AgNPs, while the Penicillium notatum (K1) strain was found to be the most potent, demonstrating biosynthetic ability. The biologically synthesized silver nanoparticles showed excellent antibacterial activity against the bacteria Escherichia coli (ATCC10536), Bacillus subtilis, Staphylococcus aureus (ATCC9144), Pseudomonas aeruginosa (ATCC10145), Enterococcus faecalis, and Listeria innocua (ATCC13932). Furthermore, three major diffraction peaks in the XRD characterization, located at the 2θ values of 28.4, 34.8, 38.2, 44, 64, and 77°, confirmed the presence of AgNPs, while elemental composition analysis via EDX and spherical surface topology with a scanning electron microscope indicated that its pure crystalline nature was entirely composed of silver. Thus, the current study indicates the enhanced antibacterial capability of mycologically synthesized AgNPs, which could be used to counter multidrug-resistant pathogens.

Among the microbial enzymes protease and amylase are the most valuable enzymes which have been has diversified applications and used extensively because of their capabilities in the degradation of organic wastes, application in biofuels, agricultural, pharmaceuticals, chemical and biotechnological industries. The aim of the current research work was the purification, characterization and application of alkaline proteases extracted from Bacillus cereus AUST-7. Various concentrations of ammonium sulphate were applied for enzyme precipitation. Sephadex-G 100 was used in FPLC system for separation of protease from other proteins. SDS-PAGE was used to measure the molecular weight of required alkaline protease. Relative activities were determined against different pH, temperature, and incubation period to measure the enzymes activity. Stability of pH, temperature and various metal ions and inhibiter were also studied. Purified enzymes were applied on the goat skin to explore the dehairing efficacy. A 6.5 purification fold and 1163.50 U/mg of specific activity were obtained at 70% saturation and 35. 91 purification fold and 8902 U/mg of specific activity were observed after FPLC separation. The 35 kDa molecular size of protease enzyme was exhibited on the SDS-PAGE. The purified enzyme was stable at pH 10, temperature 55 °C and 35 min of incubation period. The purified enzyme was found to be stable at pH 8–11, thermo-stability at 50 °C and phenyl methyl sulphonyl fluoride (PMSF) and di-isopropyl fluorophosphates (DFP) inhibited the enzyme activity. The enzyme has good potential as dehairing agent in leather industries.

The important role of Lactiplantibacillus plantarum strains in improving the human mucosal and systemic immunity, preventing non-steroidal anti-provocative drug-induced reduction in T-regulatory cells, and as probiotic starter cultures in food processing has motivated in-depth molecular and genomic research of these strains. The current study, building on this research concept, reveals the importance of Lactiplantibacillus plantarum 13-3 as a potential probiotic and bacteriocin-producing strain that helps in improving the condition of the human digestive system and thus enhances the immunity of the living beings via various extracellular proteins and exopolysaccharides. We have assessed the stability and quality of the L. plantarum 13-3 genome through de novo assembly and annotation through FAST-QC and RAST, respectively. The probiotic-producing components, secondary metabolites, phage prediction sites, pathogenicity and carbohydrate-producing enzymes in the genome of L. plantarum 13-3 have also been analyzed computationally. This study reveals that L. plantarum 13-3 is nonpathogenic with 218 subsystems and 32,918 qualities and five classes of sugars with several important functions. Two phage hit sites have been identified in the strain. Cyclic lactone autoinducer, terpenes, T3PKS, and RiPP-like gene clusters have also been identified in the strain evidencing its role in food processing. Combined, the non-pathogenicity and the food-processing ability of this strain have rendered this strain industrially important. The subsystem and qualities characterization provides a starting point to investigate the strain’s healthcare-related applications as well.

Heavy metals are a growing threat to human health due to the resulting damage to the ecology; the removal of heavy metals by lactic acid bacteria (LAB) has been a focus of many studies. In this study, 10 LAB strains were evaluated for their ability to absorb and tolerate lead. Lactobacillus plantarum YW11 was found to possess the strongest ability of lead absorbing and tolerance, with the rate of absorption as high as 99.9% and the minimum inhibitory concentration of lead on YW11 higher than 1000 mg/L. Based on the isobaric tags for relative and absolute quantitation (iTRAQ) proteomics analysis of YW11, a total of 2009 proteins were identified both in the lead-treated strain and the control without the lead treatment. Among these proteins, 44 different proteins were identified. The abundance of 25 proteins increased significantly, and 19 proteins decreased significantly in the treatment group. These significantly differential abundant proteins are involved in the biological processes of amino acid and lipid metabolism, energy metabolism, cell wall biosynthesis, and substance transport. This study contributed further understanding of the molecular mechanism of L. plantarum in the binding and removal of lead to explore its potential application in counteracting heavy metal pollution of environment, food, and other fields.