Applied Microbiology: Open Access
Open Access

Abstract

Isolation and Identification of Bioactive Molecules Produced by Entomopathogenic bacteria, Acinetobacter calcoaceticus

S. Remya Reghunath, JV Siji, C Mohandas and Bala nambisan

Objective: To isolate and identify the bioactive metabolites produced by Acinetobacter calcoaceticus associated with entomopathogenic nematode, Steinernema sp.

Methods: In order to get maximum growth of bacteria and thereby maximum yield of organic extract optimization of basal media, temperature, pH and agitation speed was done. Effect of additional carbon source was also studied by doing fermentation using selected basal media at optimized conditions. Cell free culture obtained after fermentation is separated using ethyl acetate and the organic part is concentrated. Organic compounds were purified by column chromatography and identified using spectral techniques like HPLC, NMR and FTIR. Antimicrobial activity of the cell free extracts and organic compounds were tested by well diffusion technique.

Results: Cyclo (Pro-Tyr) and cyclo (Pro-Leu) were the compounds identified from organic extracts produced by Acinetobacter calcoaceticus, associated bacteria of entomopathogenic nematode, Steinernema sp. Cyclo (Pro-Tyr) showed antifungal activity against Candida albicans with 10 mm ZOI.

Conclusion: From the results it is possible to conclude that the entomopathogenic nematode and the associated bacteria could be promising source of bioactive compounds, and warrant further study. Significance and interest of study: The information obtained can be useful for commercial utilization.