Bacillus megaterium isolated from poultry farm soil was identified by standard biochemical tests and screened for the production of serine protease. Production of serine protease was done using 5 different medias by varying the type of amino acid added. The purification was done by salt precipitation, dialysis and DEAEcellulose ion exchange chromatography. The proline containing media obtained the highest fold purification out of the five different medias (leucine, lysine, proline, tryptophan and methionine cotaining media). The enzyme showedan optimal activity at the temperature 37°C and the pH 6 which are known as its optimum temperature and pH respectively. The enzyme was proved as a Mn2+ dependent serine protease as it was activated by Mn2+ ions and inhibited by PMSF. The molecular weight of the enzyme was determined by SDS-PAGE technique as around 30kDa. It showed an excellent detergent activity on the blood stains and a very good stability in presence of locally available detrgents. The enzyme acted on the keratin protein of the chicken feather and showed a degrading capacity on the protein. So it was proved that the recently studied serine protease has a keratinase activity also. From these datas I conclude that the protease isolated from Bacillus megaterium is a Mn2+ dependent serine protease which has both keratinase and detergent activity.

Objective: This study was aimed to evaluate the bioactive potential (antimicrobial and antioxidant) of marine actinobacteria isolated from Thottadamarine sediment, Kannur, Kerala.Methods: The study involved isolation of marine actinobacteria from Thottada marine sediments, followed by antimicrobial and antioxidant activityof the crude extract. Finally, identification of potential isolates.Results: In this study, a total of 6 actinobacterial colonies were isolated, out of which only one isolate DV-35 showed maximum anti-microbial andanti-oxidant activity. The isolate DV-35 showed maximum inhibitory activity against Gram-negative bacterial pathogens Pseudomonas aeruginosa(18 mm) followed by Salmonella typhi (17 mm) and Klebsiella sp. (13 mm) at a dose of 100 μg/ml. In antifungal activity, extract showed maximumactivity against Aspergillus niger (19 mm) followed Aspergillus flavus (17 mm) at a dose of 100 μg/ml. Simultaneously the extract was evaluated for itsantioxidant activity. The potential isolate DV-35 also showed moderately higher antioxidant activity in various screening assay, viz., 2,2-diphenyl-1-picrylhydrazyl scavenging assay (80.12%), metal chelating assay and reducing power assay (76%) at a concentration of 100 μg/ml. Potential isolateDV-35 was identified as Streptomyces variabilis DV-35 using molecular 16S rRNA sequencing.Conclusion: The results obtained suggest that the extract is having bioactive metabolites that can be considered as a potential source for antimicrobialand anti-oxidant drug development.Keywords: Marine actinomycetes, Anti-microbial activity, Anti-oxidant activity, Pseudomonas aeruginosa, Aspergillus niger, Streptomyces variabilis.