Optimization of fermentation conditions for the production of ethanol from sago starch by co-immobilized amyloglucosidase and cells of Zymomonas mobilis using response surface methodology

• Published in: Enzyme and microbial technology 2006-01, Vol.38 (1), p.209-214
• Main Authors: Bandaru, Veera Venkata Ratnam, Somalanka, Subba Rao, Mendu, Damodara Rao, Madicherla, Narasimha Rao, Chityala, Ayyanna
• Format: Article
• Language: English
• Subjects: Amyloglucosidase; Biological and medical sciences; Biotechnology; Co-immobilization; Ethanol; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Microbial engineering. Fermentation and microbial culture technology; Response surface methodology; Sago starch; Zymomonas mobilis
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2005.06.002

Statistical experimental design was used to optimize the conditions of simultaneous saccharification and fermentation (SSF), viz. temperature, pH and time of fermentation of ethanol from sago starch with co-immobilized amyloglucosidase (AMG) and Zymomonas mobilis MTCC 92 by submerged fermentation. Maximum ethanol concentration of 55.3 g/l was obtained using a starch concentration of 150 g/l. The optimum conditions were found to be a temperature of 32.4 °C, pH of 4.93 and time of fermentation of 17.24 h. Thus, by using SSF process with co-immobilized AMG and Z. mobilis cells MTCC 92, the central composite design (CCD) was found to be the most favourable strategy investigated with respect to ethanol production and enzyme recovery.