ROCHELLE FERNANDEZ, RADHIKA RAMACHANDRAN* AND KANNAN NALLAKUMAR
Abstract
The present investigation is undertaken with an aim to check the protease enzyme production by marine Actinobacteria isolated from Pulicat Lake. 100 isolates of marine Actinobacteria was screened for protease enzyme production, among the 100 isolates screened 16 showed positive results which were indicated by growth and clear zone formation on skim milk agar media plate. It was then further screened and a high protease potential isolate RA71 was selected. Potential strain was further used for protease production. The isolate RA71 was identified by morphological, cultural, biochemical, numerical and molecular characterization, which revealed that the isolate belonged to Streptomyces sp. and was identified as Streptomyces pactum. The isolate showed various growth patterns in the presence of varying pH, temperature, carbon, nitrogen and metal ion concentrations. The optimal temperature of the enzyme was 40R¬C at pH 6.5. The best carbon and nitrogen sources were found to be fructose and yeast extract. Among the different metal ion sources such as sodium chloride, magnesium chloride, manganese chloride and potassium chloride, maximum protease production was observed when magnesium chloride was supplemented in the medium. By ammonium sulphate precipitation and dialysis the enzyme was partially purified. Partially purified enzyme exhibited a molecular weight of about 49.1kDa as estimated by SDSPAGE. Industrial enzymes from marine Actinobacteria obtained from the Bay of Bengal are limited. Since, it is worth to investigate on protease enzyme production from the previously isolated Actinobacteria thus obtained from Pulicat Lake; the back water of the Bay of Bengal, Tamil Nadu, India.