Abstract
Objective: The aim of the study was to evaluate antibacterial and antioxidant potential of the actinomycete isolate Streptomyces laurentii strain VITMPS isolated from marine soil, Chennai, Tamil Nadu, India.
Methods: The antibacterial activity of crude extract was tested against two bacterial pathogens and the DPPH assay was determined for free radical scavenging potential. The morphological, physiological and the biochemical properties of the strain VITMPS was confirmed by conventional methods and genotypic characterization were carried out using 16SrDNA partial gene sequencing. Results: The strain VITMPS was identified as Streptomyces spp. on biochemical and morphological characterization. Phylogenetic tree was constructed and the 16S rRNA gene sequence showed 99% similarity to Streptomyces laurentii strain NBRC 15422. The antibacterial activity studied was found to exhibit the maximum spectra of activity at 1mg/mL concentration against Bacillus cereus (35 mm) Escherichia coli (35 mm). The lowest Minimum Inhibitory Concentration (MIC) of the crude extract against Bacillus cereus (MTCC No: 6840) and Escherichia coli (MTCC No: 1588) was found at 100 µg mL-1, respectively. The ethyl acetate extract possessed DPPH free radical scavenging activity at 1 mg/ mL with 83% inhibition. Conclusion: The antibacterial and antioxidant activity of the extract clearly indicates the marine environment is the vast sources for the isolation of bioactive compounds from actinomycetes.Keywords: Actinomycetes, therapeutics, metabolites, bioactive compounds, free radicals.
Graphical Abstract