Isolation, Characterization of Antibacterial Methyl Substituted β-Lactum Compound from Streptomyces noursei DPTD21 in Saltpan Soil, India

Abstract

The taxonomic position of an actinobacteria isolated from the Indian saltpan was established the phenotypic and genotypic characteristics. The actinomycete isolate DPTD21 had chemotaxonomic and morphological characteristics consistent with its classification in the genus Streptomyces and formed a distinct phyletic line in the 16S rDNA gene sequence analysis. The prominent cellular fatty acid were tridecanoic acid (C13:0), penta eosanoic acid (C25:0) and unsaturated fatty acids such as palmitic acid (C16:1), elaidic acid (C18:10). The DNA GC content was 60 %. The isolate DPTD21 (MTCC 6704, DQ 279757) was considered to be a type strain of genus Streptomyces for which the name Streptomyces noursei is proposed. The antibacterial compound was characterized and identified by determination of melting point, elemental analysis and spectroscopical evaluation such as UV, IR, NMR and Mass spectra. On the basis of physical and chemical properties of the antibacterial compound isolated from Streptomyces noursei DPTD21 was identified as methyl substituted β-lactum compound. This compound was dissolved in three solvents. The maximum inhibition of the compound was observed against E. coli, but resistant to pyridine solvent. Moderate level of inhibition (mm) was observed with V. cholerae (13.0±0.77) in aniline, S. dysenteriae (14.5±0.4) in petroleum ether, P. aeruginosa (15.5±0.41) in ethyl acetate and K. pneumoniae (14.16±0.49) in ethyl acetate.

Key words:

• Marine Streptomyces
• Salt pan soil
• 16S rDNA analysis
• antibacterial activity