Production and partial characterization of collagenase from marine NRC2aza using chitin wastes

Background
The marine ecosystem has generated considerable interest for the isolation of new microorganisms, especially spp. It is considered a cheaper source of precious enzymes such as collagenase.
Objective
This study aimed to produce new collagenase enzymes from the locally isolated marine spp. grown on marine wastes for application in industrial fields.
Materials and methods
The marine isolate was identified as NRC2aza by 16S rDNA sequencing. NRC2aza was grown on basal medium composed of whole chitin wastes as the sole C and N source for the production of collagenase enzyme. Extraction of the enzyme was performed to study its characteristics.
Results and conclusion
Maximum collagenase activity (240 U/ml) was obtained after 6 days of incubation in shaken liquid cultures when whole chitin wastes (shrimp and crab wastes) were used as the sole nitrogen and carbon source. A NRC2aza isolate was shown to produce significant amounts of collagenase, reaching 1872 U/g, under solid-state fermentation using a mixture of 10 g chitin waste and 2 g of feather. Successive ammonium sulfate fractionation of NRC2aza growth extract produced a group of collagenases with different molecular weights. The 80% enzyme fraction was the most active and possessed the highest collagenase activity (1106.66 U/f), reaching about 3.8-fold that of the culture filtrate. The optimum pH and temperature were 8 and 55°C, respectively, and the enzyme was stable at pH range of 6–8. The collagenase exhibited heat stability for 60 min at 50°C. Therefore, collagenases can be applied in food industry as tenderizers of red meat and in fur and hide tanning to ensure uniform dyeing of leather.