Tuesday, April 20, 2010
11-09

Evaluation of fermentation of cellulosic hydrolysates obtained by enzymatic saccharification of sugarcane bagasse pretreated by hydrothermal processing

Vinícius F. N. Silva, Priscila V. Arruda, Maria das Graças A. Felipe, Adilson R. Gonçalves, and George J. M. Rocha. Biotechnology Department, Engineering School of Lorena, University of São Paulo, Campus I, P.O.Box116, Lorena, 12602-810, Brazil

This work aims to evaluate the fermentability of cellulosic hydrolysates obtained by enzymatic saccharification of sugar cane bagasse pretreated by hydrothermal processing using Candida guilliermondii FTI 20037 yeast. The inoculum was obtained from yeast culture in synthetic medium, containing glucose as carbon source supplemented with rice bran extract, CaCl2.2H2O and (NH4)2SO4 in 50 mL Erlenmeyer flasks, containing 20 mL of medium, initial pH 5.5 under agitation of orbital shaker (200 rpm) at 30 °C for 24h. The cellulosic hydrolysates, prior to be used as fermentation medium, were autoclaved for 15 min at 0.5 atm and, later, supplemented with the same nutrients employed for the inoculum, except the glucose, using the same conditions for the inoculum, however the period was 48h. Preliminary results showed the highest consumption of glucose (97%) for all the hydrolysates, already at 28h of fermentation. The highest concentration of ethanol (20.5 g/L) in the proceeding of sugar cane of bagasse pretreated by hydrothermal processing (195 °C/10 min in 20 L reactor) and delignificated with NaOH 1.0% (m/v), 100 °C, 1h in 500 mL stainless steel ampoules  immersed on oil bath. Acknowledgements: FAPESP, CAPES and CNPq.