Phosphate solubilizing microorganisms (PSMs) mineralize phosphate (PO₄³⁻) to make phosphorous available for plant uptake. This study is designed to isolate the PSMs from the subtropical environmental samples. Total 35 bacterial and 18 fungal isolates were found to be effective P solubilizers depend on their ability of P solubilization that were determined qualitatively and quantitatively using National Botanical Research Institute Phosphorus media. Efficient PSMs that were solubilizing phosphate in maximum amount were identified as Pseudomonas aeruginosa, Serratia marcescens, Pseudomonas mosselii, Bacillus licheniformis, Bacillus subtilis, Bacillus species, Aspergillus flavus, Aspergillus foetidus, Aspergillus niger, Aspergillus tubingensis, and Penicillium chrysogenum. Among them, A. tubingensis was observed as the most efficient phosphate solubilizing strain. For the first time, combined phosphate solubilization activity of A. tubingensis with other efficient phosphate solubilizers was checked and found that A. tubingensis and P. aeruginosa acted synergistically and solubilized phosphate in increased amount. High-performance liquid chromatography results revealed that A. tubingensis produced variety of organic acids including succinic, gluconic, oxalic, and citric acids. Scanning electron microscopy results confirmed the presence of firmly attached large fungal hyphae on tri-calcium phosphate (Ca₃(PO₄)²). Thus, the results suggest that the use of these PSMs either single or combined as bioinoculants will help to increase the availability of soluble phosphorous.

Biogenic synthesis of silver nanoparticles (AgNPs) is more eco-friendly and cost-effective approach as compared to the conventional chemical synthesis. Biologically synthesized AgNPs have been proved as therapeutically effective and valuable compounds. In this study, the four bacterial strains Escherichia coli (MT448673), Pseudomonas aeruginosa (MN900691), Bacillus subtilis (MN900684) and Bacillus licheniformis (MN900686) were used for the biogenic synthesis of AgNPs. Agar well diffusion assay revealed to determine the antibacterial activity of all biogenically synthesized AGNPs showed that P. aeruginosa AgNPs possessed significantly high (p < 0.05) antibacterial potential against all tested isolates. The one-way ANOVA test showed that that P. aeruginosa AgNPs showed significantly (p < 0.05) larger zones of inhibition (ZOI: 19 to 22 mm) compared to the positive control (rifampicin: 50 µg/mL) while no ZOI was observed against negative control (Dimethyl sulfoxide: DMSO). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) concentration against four test strains also showed that among all biogenically synthesized NPs, P. aeruginosa AgNPs showed effective MIC (3.3-3.6 µg/mL) and MBC (4.3-4.6 µg/mL). Hence, P. aeruginosa AGNPs were characterized using visual UV vis-spectroscopy, X ray diffractometer (XRD), fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The formation of peak around 430 nm indicated the formation of AgNPs while the FTIR confirmed the involvement of biological molecules in the formation of nanoparticles (NPs). SEM revealed that the NPs were of approximately 40 nm. Overall, this study suggested that the biogenically synthesized nanoparticles could be utilized as effective antimicrobial agents for effective disease control.

Feather wastes-byproduct of commercial poultry processing plant is produced in large amounts. Keratinolytic enzymes produced by feather degrading bacteria can easily degrade these waste products releasing pure keratin as a residue. The aim of present study was to isolate, and characterize feather degrading bacteria as well as assess the keratinolytic potential of purified enzyme. Three feather degrading bacteria (dps3, wps1 and dcs1) were isolated from feathers of domestic chickens. Preliminary characterization of isolated bacteria revealed these isolates belonging to genus Bacillus. 16S rRNA gene sequencing identified the isolates as B. subtilis dps3 (MW255302), B. cereus wps1 (MW255303) and B. licheniformis dcs1 (MW255304). Cell free supernatant of B. licheniformis dcs1 degraded feathers completely in 14 days indicating its keratinolytic ability. Purification of keratinase enzyme from B. licheniformis dcs1 was performed using column chromatography. SDS-PAGE indicated its molecular weight as 32 KDa. Kerotinolytice activity was maximum at optimum pH of 7 and 45°C temperature. Enzyme showed the potential to degrade keratin material such as hairs and nails of humans. Findings of current study suggested that purified enzyme possess potential to upgrade nutritional quality of poultry waste containing keratin and might play as important biotechnological tool for keratin hydrolysis.