Spectroscopic and chromatographic identification of bioprospecting bioactive compounds from cow feces: Antimicrobial and antioxidant activities evaluation of gut bacterium Pseudomonas aeruginosa KD155.

The prime objective of our study was to evaluate antimicrobial and antioxidant activities of Pseudomonas aeruginosa KD155 isolated from cow dung. For identification of the isolate KD155, molecular techniques were employed and obtained 16S rRNA gene sequence was deposited in the NCBI GenBank under the accession number MK801234. Extracellular crude extract of P. aeruginosa KD155 displayed significant antimicrobial activity against Bacillus subtilis (MTCC 441) and Staphylococcus aureus (MTCC 7443) in comparison to tetracycline and ketoconazole. The resistance of extracellular crude chloroform extract to DPPH scavenging activity was also observed with 77.49% inhibition rate reflecting strong antioxidant activity. In addition, HP-TLC, FT-IR and GC-MS analysis of extracellular chloroform crude extract was done which revealed phenolic compound (quercetin) as major bioactive metabolite being produced by our isolate KD155. Further, the stability of 16S rRNA sequence of the strain was studied using bioinformatics tools viz. mfold and NEB cutter indicating the thermodynamic stability of its gene sequence.