Production and statistical optimization of culture condition for Nattokinase from Bacillus subtilis MTCC 2616

Abstract

Nattokinase which is a thrombolytic enzyme has a wide range of application in medicine, health care and pharmaceutical industry. It provides many health benefits like chronic inflammation, muscle spasms, poor healing, cure of hemorrhoids, helps to improve blood circulation, blood vicocity etc. In this study, a bacterium named Bacillus subtilis MTCC 2616 was employed for optimization of fermentation media and physical parameter in order to be applied for maximum Nattokinase enzyme production. Different carbon sources like lactose and glycerol was used in production media. Maximum nattokinase activity was obtained in lactose conataing media. Six factors including Lactose, Tryptone,Yeast extract, K2HPO4,MgSO4 and CaCl2 were screened using placket burman design. In range studied, Lactose, Tryptone, Yeast extract, K2HPO4 and CaCl2 had significant effect on Nattokinase activity. Significant factors were optimized using Response surface methodology in central composite design. The optimized media containing (g/L): Lactose (7.50),Tryptone (12.00),Yeast extract (12.00),K2HPO4 (4.50) and CaCl2 (0.20) which showed maximum Nattokinae activity and Specific activity 576.88 U/ml and 25.66 U/mg respectively. Central composite design was used to build statistical model to study the effect of two variables pH and temperature on Nattokinase production. The optimal conditions for pH and temperature were found to be 7.4 and 34.85°C respectively. Maximum nattokinase activity and specific activity was found to be 593.08 U/ml and 25.96 U/mg respectively. Caesinolytic activity of Nattokinase in optimal conditions was increased from 321 U/ml to 593.08 U/ml in optimized condition. The fibrinolytic activity using synthetic substrate was enhanced from 1089.50 U/ml to 1565.16 U/ml in optimal conditions. Structural and binding analysis of Nattokinase with substarte caesin was studied using Docking which showed that Nattokinase is the enzyme which binds to caesin more favorably to the tyrosine residue.