Deproteinization potential and antioxidant property of haloalkalophilic organic solvent tolerant protease from marine Bacillus sp. APCMST-RS3 using marine shell wastes

The current increase in the vast amount of marine crustacean shell waste produced by the fish processing industries has led to the need to find new methods for its disposal. Hence, the present study was carried out via marine shell wastes as substrate for protease production. The maximum production (4000.65 U/ml) from Bacillus sp. APCMST-RS3 was noticed in 3:1% shrimp and oyster shell powder (SOSP) as substrate. Purified protease showed 53.22% and 22.66% enzyme yield; 3.48 and 8.49 fold purity with 40 kDa molecular weight; whereas, its Km and Vmax values were 0.6666 g/l, 1111.11 U/ml. This enzyme showed optimum activity at pH 9 and 60 °C temperature. Also, it retained maximum protease activity in the presence of NaCl (2.5 M), surfactants (Tween 20, 40, 60, 80 and SDS) and metal ions (MnCl2, CaCl2, HgCl2 and BaCl2) and solvents. The candidate bacterium effectively deproteinized (84.35%) shrimp shell and its antioxidant potentials.