Isolation and Identification of Antimicrobial Compounds from Bacillus Cereus Obtained from Soil

Abstract

Bacillus cereus cell-free culture filtrate from soil was highly antibacterial. Two bioactive substances were isolated from the bacterial culture filtrate ethyl acetate extract by silica gel column chromatography. The compounds' structure and stereochemistry were determined by spectroscopic investigations (UV and FTIR) and Marfey's technique. The molecules were cyclo(L-Pro-L-Val), and 3,5-dihydroxy-4-ethyl-trans-stilbene. Pseudomonas aeruginosa Staphylococcus aureus, and Escherichia coli were all inhibited by compounds both the isolated molecules. Best antibacterial activity was observed with 3,5-dihydroxy-4-ethyl-trans-stilbene (6 μg/ml) against Escherichia coli. We conclude that the Bacillus cereus strain from soil is a promising source of natural bioactive secondary metabolites that might be used to develop new medications in agriculture and pharmacology.