α-Amylase Production by Bacillus amyloliquefaciens Using Agro Wastes as Feed Stock

Dhanya Gangadharan, K. Madhavan Nampoothiri* and Ashok Pandey

Biotechnology Division, National Institute for Interdisciplinary Science and Technology (NIIST), CSIR, 695 019 Trivandrum, India

Article history:

Received September 13, 2010
Accepted February 15, 2011

Key words:

α-amylase, Bacillus amyloliquefaciens, fermentor, bioreactor, aeration, submerged fermentation


The productivity of enzyme fermentations depends critically on maintaining a high oxygen transfer rate to satisfy the optimal oxygen demand of the microorganism for product formation. Among the several factors that affect oxygen transfer rates in a fermentor are the air flow rate and agitation. The production of α-amylase by Bacillus amyloliquefaciens was performed in 600-mL and 5-litre fermentor with a working volume of 300 mL and 3 L, respectively. The experiments indicated a requirement of high rates of aeration to enhance the enzyme yield. The biomass yield and productivity of the enzyme were found to have a linear relationship with the air flow rate, and the highest productivity was observed at 1.0 vvm. A maximum productivity of 41.4 U/(mL·h) was obtained after 14 h of fermentation in 600-mL fermentor system and a comparable productivity of 40 U/(mL·h) was obtained after 12 h in the 5-litre fermentor.

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