Alkaline Proteases Produced by Bacillus licheniformis RP1 Grown on Shrimp Wastes: Application in Chitin Extraction, Chicken Feather-degradation and as a Dehairing Agent

作者：Haddar Anissa^*; Hmidet Noomen; Ghorbel Bellaaj Olfa; Fakhfakh Zouari Nahed; Sellami Kamoun Alya; Nasri Moncef

来源：Biotechnology and Bioprocess Engineering, 2011, 16(4): 669-678.

DOI：10.1007/s12257-010-0410-7

• shrimp wastes
• Bacillus licheniformis RP1
• enzymatic deproteinization
• keratine-degradation
• dehairing function

The current increase in the amount of shrimp wastes produced by the shrimp industry has led to the need in finding new methods for shrimp wastes disposal. In this study, Bacillus licheniformis RP1 was shown to produce proteases when grown in media containing shrimp wastes powder as a sole carbon and nitrogen source, indicating that this bacteria could obtain its carbon and nitrogen requirements directly from shrimp wastes. The maximum protease production was obtained when the strain was grown in a medium containing (g/L): shrimp wastes powder 30, KCl 1.5, K(2)HPO(4) 0.5, and KH(2)PO(4) 0.5. Using casein zymography, the crude protease preparation was found to produce at least seven proteases. The proteases of B. licheniformis RP1 were tested for shrimp waste deproteinization in the preparation of chitin. The percent of protein removal after 3 h hydrolysis at 60 degrees C and at an enzyme/substrate (E/S) ratio of 0.5 and 5 (Unit of enzyme/mg of protein) were about 68 and 81%, respectively. Additionally, B. licheniformis RP1 showed important feather degrading activity. Complete solubilisation of whole feathers was observed after 24 h of incubation at 50 degrees C. More interestingly, the RP1 proteolytic preparation demonstrated powerful dehairing capabilities for hair removal from skin. Collagen, which is the major leather-forming protein, was not significantly degraded. Considering its promising properties, B. licheniformis RP1 enzymatic preparation may be considered a potential candidate for future use in several biotechnological processes.

• 出版日期2011-8