Isolation and description of keratinase producing marine actinobacteria from South Indian Coastal Region

A unique standard starch casein medium has been implemented for the isolation of actinobacteria from the south Indian marine sediments. A combination of techniques, morphological, physiological and biochemical tests provided the evidence for the isolated actinobacteria. All the 56 isolates were inoculated on milk agar and soya meal agar plates for the primary proteolytic screening and the proportional study was made by ANOVA. Among the 56 isolates, nine showed proteolytic activity in terms of making clear zone around their colony on the plates. Then, nine isolates were subjected to the secondary screening on feather broth where three isolates (IS -1, 2 and 18) showed degradation of feather between seven and ten days. The keratinolytic characters of crude enzymes were scrutinized by feather keratin as substrate and the protein concentration was determined. Then, the isolates were identified at molecular level by 16S rRNA gene amplification technique. Key words: Actinobacteria, keratinase, milk agar, soya meal agar, 16S rRNA gene amplification.