Keratinases are well-recognized enzymes with the singular power of taking down the recalcitrant structural proteins such as keratin. Their prospective in bio-waste management of feather waste has been well recognized since long. In present scenario, they have acquired importance in various other industrial applications. The present study mainly focused on the isolation of keratin degrading bacteria and its use in optimization of culture conditions to maximize the keratinase production. The isolated strain was identified as Bacillus subtilis strainS1 according to morphological and biochemical characteristics followed by 16 S rRNA sequencing (accession no: LC054177). The influence of cultivation temperature and initial pH of the medium on keratinase production revealed the optimal values of the temperature and pH as 40 °C and 7, respectively. Maximum keratinolytic activity was observed at 72 h after incubation. Optimized value for inoculum size and substrate concentration was found to be 5% and 1% respectively, 150 rpm found to be the optimum agitation level. The best additional nitrogen source was Beaf extract and all the additional carbon sources showed a negative effect on keratinase production. These results indicate that this bacterial strain shows a high potential for keratinase production in submerged-state fermentation, and use of feather waste as the substrate can be implemented for keratinous solid waste management.

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