Bioactive potential of Pseudomonas alcaliphila isolated from a marine sponge against human pathogens

Metabolite extraction is considered as one of the important steps in metabolomics, the marine metabolite are the new source of the most antimicrobial agents used in both pharmacological and biological applications. In the present study, sponge associated bacterial metabolites was investigated. A total of 20 bacterial strains were isolated from the sponge Haliclona sp., All the strains were screened primarily with cross streaking method against human bacterial pathogens. The potent isolate was chosen based on the good inhibitory activity and metabolite extraction was achieved using chloroform: methanol mixture. The metabolites were then checked for their antimicrobial activity by disk diffusion and also minimum inhibitory concentration was determined. Out of 20 bacterial strains, only one strain selected based on the good inhibitory activity against pathogens and the strain was identified as Pseudomonas alcaliphila based on the biochemical and16S rRNA sequencing. The results revealed that the metabolites exhibited high activity and it was found that Klebsiella pneumoniae was inhibited high with the diameter of 22 mm followed by Salmonella Typhi (15 mm), E.coli (12 mm), and Bacillus subtilis (15 mm). The MIC was observed at 31.25 µg/ml against all pathogens. Results of TLC exhibited the Rf value at 0.86 and the FTIR results revealed the presence of C=o, amide bond, amino acids and methoxy groups. In GC-MS results showed that the metabolites mostly contain fatty acids and alkenes compounds. Thus, this marine active compound was considered as a novel compound for biological applications and may be a potential drug for therapeutic use.