In-vitro antitumor activity and metabolic finger printing of the actinomycetes isolated from various ecological niches in Pakistan

Actinomycetes are gram positive bacteria with high g+c content in their dna and are capable of producing variety of secondary metabolites. many of these metabolites possess different biological activities and have the potential to be developed as therapeutic agents. the aim of the present study was to screen actinomycetes of various ecological niches in pakistan for cytotoxic and antitumor compounds. several water and soil samples were collected from different areas in pakistan and more than 500 actinomycete isolates were recovered by selective isolation techniques. among them 120 isolates were selected on different morphological basis for identification and cytotoxicity. these isolates were identified on the basis of their microscopy (scanning electron microscopy),morphological,biochemical and physiological behavior's along with genetic characterization. the isolates such as mka 17,ssa 13 and kml 2 showed highest mortality rate with having 92%,84% and 84% dead larvae (artemia salina) after 24 hours respectively. theses potent isolates were tested against proliferative cell lines by methyl thiazolyl tetrazolium (mtt) bioassay method. isolate kml 2 and ssa 13 showed highest antitumor activity with having ic50 values of 12.17μ g/ml and 16.4 μ g/ml against hela cell line respectively. chemical screening profile by tlc and robust uplc-ms showed distinctive chemical diversity in the extracts of selected isolates. indeed,preparative screening of isolated actinomycetes strains delivered bioactive compounds including actinomycin d and resistomycin from ssa 13 and mka 17 respectively. the genetic characterization by 16s rrna gene sequencing exhibited maximum genetic similarity with different species of the well-known genus of actinomycetes named as streptomyces. © copyright 2016 zoological society of pakistan.