Abstract
The aim of the study was to evaluate antibacterial and antioxidant potential of the actinomycete isolate Streptomyces cinnamonensis VITNS1 isolated from paddy field, Vellore, Tamil Nadu. The antibacterial activity of crude extract was tested against bacterial pathogens. The free radical scavenging potential of the crude extract was determined by DPPH assay. The morphological, physiological and the biochemical properties of the strain VITNS1 was confirmed by conventional methods and genotypic characterization was carried out using 16S rDNA partial gene sequencing. The authenticity of the crude chemical constitutes were determined by (GC-MS). The strain VITNS1 was identified as Streptomyces sp on biochemical and morphological characterization. Phylogenetic tree was constructed and the 16S rRNA gene sequence showed 99% similarity to Streptomyces cinnamonensis strain N56-1. The antibacterial activity studied against Staphylococcus aureus (26mm) was found to exhibit the best spectra of activity, followed by Pseudomonas aeruginosa (25mm), Salmonella typhi (25mm) Escherichia coli (24mm) at 30mg/mL concentration. The ethyl acetate extract possessed DPPH free radical scavenging activity at 5mg/mL with 70% inhibition. The (GC-MS) Gas Chromatography revealed the presence of six volatile compounds. Hence the results of antibacterial and antioxidant activity of the extract clearly indicated that the terrestrial environment are the major sources for the isolation of bioactive compounds from actinomycetes and a promising tool for drug discovery.
Keywords: Antibacterial activity, antioxidants, bioactive compounds, soil actinomycetes.