ORIGINAL PAPER Investigation on Production and Purification of Haloalkalophilic Organic Solvent Tolerant Protease from Marine Shell Waste and its Bioconversion to Chitin by Aquatic Bacillus sp. APCMST-CS4 Thirumalai Maruthiah 1 • Beena Somanath 2 • Grasian Immanuel 1 • Arunachalam Palavesam 3 Received: 15 March 2016 / Accepted: 18 July 2016 Ó Springer Science+Business Media Dordrecht 2016 Abstract The current increase in the bulge amount of marine fish wastes produced by the marine industries has led to search for new efficient and judicious disposal methods. Hence the present study was undertaken on production and purification of halophilic organic solvent tolerant protease (HOSP) from marine Bacillus sp. APCMST-CS4 using marine shell wastes as substrate. Statistical media obtained optimization inferred that, anchovy powder (20.00 g/L), crab shell powder (12.5 g/ L), NaCl (100.00 g/L), and CaCl 2 (3.00 g/L) favored maximum protease activity (1,398.20 U/mL) and it was found to be an alkaline HOSP. This HOSP was purified to 8.10 fold with 29.52 U/mg specific activity and its molecular weight was 21 kDa. Further this HOSP was tolerant to temperature (60 °C), pH (8), NaCl (2.5 M), metals, surfactants, solvents and commercial detergents and exhibited maximum activity. The serine and metal- loprotease inhibitors were highly inhibited the activity of HOSP; hence this protease was referred as serine metal- loprotease. The candidate strain had the ability to deproteinize (80.17 %) the crab shell waste and also displayed maximum antioxidant activity. FTIR and 13 C CP/MAS NMR study revealed the presence of pure µ- chitin in the HOSP fermented crab shell waste and it emerged as a potential alternate method for the produc- tion of chitin. Graphical Abstract Keywords HOSP Á Marine shell fish wastes Á Crab shell chitin Á FTIR Á 13 C CP/MAS NMR Á Antioxidant activity Introduction Marine industry generates 50–60 % of the total weight of shellfish as waste with protein (35–50 %), chitin (15–25 % of dry weight) and inorganic compound (calcium carbonate) which are considered as major environmental pollutants due unjudicious disposal [1, 2]. Further bioconversion of these materials has been proposed as waste resource management and also pollution control. The utilization of these wastes not only solves the environmental problem but also decreases the production costs of microbial proteases [3]. Among the microbial proteases, alkaline protease places 40 % of the total world enzyme production, with specific applications in bak- ery, brewing, detergent, diagnostic reagents, feeds modifica- tion, leather finishing, laundry additives, pharmaceuticals, and peptide synthesis, silk, silver recovery from X-ray/photo- graphic film, soy processing, and waste treatment [4]. & Arunachalam Palavesam plavesh06@gmail.com 1 Centre for Marine Science and Technology, Manonmaniam Sundaranar University, Rajakkamangalam, Kanyakumari District, Tamilnadu 629 502, India 2 Department of Zoology, Rani Anna Government College for Women, Manonmaniam Sundaranar University, Tirunelveli, Tamilnadu 627 012, India 3 Department of Animal Science, Manonmaniam Sundaranar University, Tirunelveli, Tamilnadu 627 012, India 123 Waste Biomass Valor DOI 10.1007/s12649-016-9636-8