Potential Biotechnological Use of Alkaline Protease Producing Bacteria : Leather Industry, Detergent and Dye Degradation

In this research work, samples were collected from 4 stages of leather processing; soaking, liming, deliming & bating. Quantitative bacterial analysis showed that aerobic heterotrophic bacterial load of the samples ranged between 134,000 & 344,000 and 104,000 & 600,000 cfu/ml in NA medium and PYG medium, respectively. Total of 70 bacterial isolates were isolated & based on better proteolytic activity 27 were selected for detail study. All 27 isolates were Gram positive, rod shaped, spore former and Bacillus. In SMA medium proteolytic activity was measured as zone ratio which ranged from 2.610.44-6.420.95. With better proteolytic activities 4 isolates were confirmed as Bacillus subtilis B20, B. subtilis PB18, B. amyloliqefaciens Egy25 and Bacillus sp. BVC38 based on 16s rDNA sequencing. Alkaline protease production range was 48.38-169.70 U/ml & Bacillus subtilis B20 was the maximum producer. Crude enzymes showed good detergent additive performance & could effectively dehair like the chemicals (lime-sulphide) used for dehairing. 8 isolates showed potentiality in pollution management through decolourization of Acid Brown-75 & Acid Brown-14 dyes.