Study of antimicrobial activity of bacterium indigenous to the North West of Iran

Abstract

In the recent decades, pathogenic microorganisms with resistance to common drugs have become wide spread. These developments lead to significant complications in treating infections and pose a serious challenge to modern medicine. The search for new natural antibiotics that overcome drug resistance of pathogenic microflora is a solution to this problem. Microbial natural products are the origin of most of the antibiotics on the market today. There is an alarming scarcity of limited number of antibiotics currently under development in the pharmaceutical industry. Aim We investigated the ability of Tabrizicola aquatica gen. nov. sp. nov. to produce new antimicrobial agents. Materials and Methods Growth inhibition of microorganisms by the supernatant of Tabrizacola aquatica investigated using well diffusion test. T. aquatica was incubated at 40 in shaking incubator maintained at 150 rpm for 14 days. The fresh culture was centrifuged at 10000 rpm for 10 minutes to obtain supernatant, which was sterilized using 0.2 m filter paper and lyophilized. About 100 ml of the diluted lyophilized supernatant was added to the wells. The plates then were incubated at 37 . Antimicrobial activity was determined by measuring the inhibition zone diameter after 48 hours of incubation. Results The bacterial filtrates showed significant antagonistic effect against Escherichia coli, Rhizobium radiobacter, Erwinia amylovora, Pseudomonas syringae, Botrytis cinerea, Neurospora crassa and Fusarium oxysporum. However it showed no inhibitory action on the Aspergillus flavus and klebsiella pneumoniae. The effect of the supernatant was a reduced growth zone on Xanthomonas camoestris, Shigella flexneri, Pseudomonas aeruginosa, streptococcus aureus and Bassilus cereos . Discussion Microbial natural products remain the most promising source of novel antibiotics. Our results highlighted the scope for characterization of the metabolite and could be a candidate in the generation of new antimicrobial agents.