Taxonomic characterization of rare actinobacteria isolated from mangrove ecosystem of Gilakaladindi, Krishna District, Andhra Pradesh

The present work is aimed to isolate, identify and characterize the rare actinobaterial strains VJSY-1 and VJSY-14 from the mangrove soils of Gilakaladindi, Krishna district of Andhra Pradesh. The soil samples were collected, pre treated with calcium carbonate and used for the isolation of rare actinobacterial strains. Identification of these strains was carried out by polyphasic taxonomical studies including morphological, cultural, physiological, biochemical characters along with 16S rRNA analysis. Phylogenetic tree was constructed using Molecular Evolutionary Genetic Analysis software (MEGA) version 6.0. Phylogenetic analysis by 16S rRNA sequencing revealed that the strains VJSY-1 and VJSY-14 are closely related to the genus Nocardiopsis and the bioactive metabolites produced by the strains inhibited Gram positive bacteria Staphylococcus aureus (MTCC 3160), Bacillus megaterium (NCIM 2187), Bacillus subtilis, Gram negative bacteria Xanthomonas campestris (MTCC 2286), Pseudomonas aeruginosa (ATCC 9027) and Escherichia coli (ATCC 35218), and fungi like Aspergillus niger, Fusarium solani, F. oxysporum and Candida albicans (MTCC 183). Attempts are being made to optimize the cultural conditions for enhanced production of bioactive metabolites by the strains as well as characterization of the bioactive compounds.