Tuesday, April 20, 2010
8-55

Bioconversion of rice hulls to ethanol with SAA pretreatment and immobilized cellulase in calcium alginate

Edita Martini1, Dian Andriani1, Kyeong Eop Kang1, Yun-A Kim1, GobiKrishnan Sriramulu1, Don-Hee Park2, and Jong-Seong Kim1. (1) Interdisciplinary Program of Graduate School for Bioenergy and Biomaterials, Chonnam National University, Gwangju, South Korea, (2) Interdisciplinary Program of Graduate School for Bioenergy and Biomaterials, School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea

During past decades, considerable efforts have been made to utilize lignocellulose as biomass feedstock for the optimal production of bio-ethanol as an alternative source of fuel. Cellulase enzyme can be used for converting pre-treated lignocellulosic material to glucose, which can be further fermented to ethanol. The major concern in an enzymatic process is the instability of the enzyme under repetitive or prolonged use and inhibition by high substrate and product concentration. Immobilization is a very effective alternative for repetitive use of enzymes. Entrapment method of immobilization is advantageous over other methods as they do not involve chemical modification of the enzyme. In this work, rice hull was pre-treated by soaking in aqueous ammonia (SAA pretreatment) then hydrolyzed to fermentable sugar using immobilized Cellulase enzyme in calcium alginate beads. The fermentation to ethanol was carried out using Saccharomyces cerevisae yeast. The reducing sugar was determined by DNS method and the ethanol concentration by GC. The enzyme activity for immobilized and free Cellulase was calculated. Microscopic changes of rice hulls upon SAA pretreatment also observed using SEM.