Selective isolation and characterization of rare actinomycetes adopted in glacier soil of Manali ice point and its activity against Mycobacterium spp

Abstract

An exigent demand of antimicrobial agent against M. tuberculosis was lead to the isolation of novel rare actinomycetes from the unexplored cryophilic environment. Soil samples were collected from glacier ice point of Kullu Manali and processed for further studies. A novel approach was described for the isolation of rare actinomycetes from a heterogeneous population. Isolation was done by conventional and density gradient centrifugation. Sucrose gradient centrifugation showed a maximum of 24 actinomycetes isolates which belong to the genera of Streptomyces sp (12), Micromonospora sp (5) Planomonospora sp(2), Micropolyspora sp (2), Actinopolyspora sp (1) Nocardia sp (1) and Intrasporangium sp (1). Of these 24 actinomycetes, isolate Planomonospora sp (PL-2) showed potent anti-mycobacterial activity against Mycobacterium smegmatis (MTCC300) and M.tuberculosis (MTCC 6). Bioautography reveals that the R f value of active compound was 0.75 and retains the antimicrobial activity at 75° C. Based on the C 13 and H 1 NMR the active compound was characterized as 2-(2-ethenylphenyl) heptane-1-ol. Phylogenetic analysis reveals active isolate was closely related to Planomonospora alba and the Genbank accession is JQ280498.