Examining kinetic parameters of fermentation process in batch cultures on the production of alkaline protease

Abstract

Alkaline proteases are important group of enzymes because of their use in many industrial applications such as in detergent materials for the removal of the protein stains on clothes. The aim of this study is to investigate the kinetic parameters of the fermentation process inspected for alkaline protease production by using a localBacillus clausii. In this way, it is carried out under fed-batch operations of fermentation in erlyne. Designing full factorial is used for optimizing appetite composition for the three factors of sponge carbon glucose, yeast extract (organic nitrogen), salt solution (including K2HPO4, MgSO4.7H2O), and trace element solution (TES) each at two levels and designed by eight tests in total. All experiments were carried out in duplicates to decrease the possibility of errors occurring in the research. Analysis of variance (ANOVA) showed that the high coefficient of the determination (R2) value is 0.99, thus ensuring a significant adjustment of the suggested polynomial model with the experimental data. The results showed that protease production was controlled because of catabolic inhibition in the initial glucose concentration and the amount of enzyme activity which is important for protease production which increased in the end of the stationary phase that was often accompanied by sporulation phenomena. The results on comparison and inspection in batch cultures with glucose demonstrated that different values revealed that the alkaline protease was highly produced in a few hours after complete consumption of glucose. Also, mineral salts and yeast extract induce the protease production as increasing protease is a changing approach of bacteria catabolitic from development to extra cell enzyme production. Meanwhile, results showed that the detergent type do not have any effect on protease activity. Therefore, the production enzyme can be used as detergent powders. Key words: Alkaline protease, Bacillus clausii, fed-batch fermentation, sporulation, kinetic parameters, full factorial, detergent.