MOLECULAR CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY OF BIOSURFACTANT PRODUCING ISOLATE STREPTOMYCES CELLULOSAE VAR. PD66

Abstract

In the present study, the actinomycetes isolate named as PD66 (Streptomyces cellulosae var.) was screened and identified based on 16S rRNA nucleotide sequence and phylogenetic evolutionary relationship with other strains by National Collection of Industrial Microorganisms (NCIM), Pune. Biosurfactant production by the isolate PD66 was carried out using Kim’s medium with 3% olive oil as a carbon source and incubated at 27ºC for 7 days on rotary shaker at 150rpm. After 7 days, the contents of the flask were centrifuged and collected the cell free supernatant for performing the preliminary tests like oil displacement, para film-m test for confirmation of biosurfactant production, these two tests were given positive results for biosurfactant production obtained from the selected isolate PD66. Lipase activity was also checked and confirmed the extra cellular lipase enzyme release during the growth of isolate PD66 using tributyrine agar medium. Surface tension and emulsification index were also measured for evaluation of biosurfactant present in cell free supernatant broth using SLS (Sodium lauryl sulphate) as a standard. Determination of extracellular antibacterial activity of biosurfactant samples was determined for every 24hrs upto 10days using cell free supernatant by agar diffusion method. Selected isolate PD66 has showed antibacterial activity against E.coil and Staphylococcus aureus. After extraction of cell free supernatant with ethylacetate, the resultant crude extract was tested for identification of bioactive metabolite by TLC method and Bioautography technique.