FED-BATCH FERMENTATION OF BACILLUS CLAUSII FOR EFFICIENT PRODUCTION OF ALKALINE PROTEASE USING DIFFERENT FEEDING STRATEGIES

Abstract

The effect of different feeding strategies, involving constant rate and linear feeding with negative and positive slopes, on protease production of an indigenous Bacillus clausii was investigated. The results indicated that alkaline protease was produced at high levels soon after glucose was completely consumed. Alkaline protease activity was at a maximum during the constant feeding rate and in the absence of glucose and presence of mineral salts and yeast extract in the feed medium. Maximum protease production in the fed-batch culture using an optimized level of feeding composition was 2430 ± 67 U/mL, which increased by up to 35% when compared to the 1800 ± 14 U/mL produced during batch culture. During batch fermentation, the protease yield and productivity obtained were 90000 U/g and 64285 U/L · h; however, under fed-batch conditions, these were 121500 U/g and 71470 /L · h, respectively. Hence, the suggested strategy has the potential to be applied to industrial production of protease used in detergent products.