36B-28

M. G. AGUILAR-USCANGA, JR.¹, B. I. Escudero-Abarca², J. Gomez-Rodriguez², E. Rangel-Leon², and D. Livas-Lara². (1) Unidad de Investigacion y Desarrollo en Alimentos, Instituto Tecnologico de Veracruz, M. Angel de Quevedo 2777 Col. Formando Hogar, Veracruz, 91876, Mexico, (2) Veracruz, 91860, Mexico

Xylitol is an important edulcorant for the food and pharmaceutical industries. This substance is produced by chemical way through wood wastes. Recently, fermentative processes have been described using yeast and hydrolizates from lignocellulosic materials. It has been shown that inhibitors of cellular growth are acetic acid, furfural and 5-hydroximethylfurfural (5-HMF). The objective of this work was to investigate the effect of acetic acid, furfural and 5-HMF on the growth and production of acetic acid from the wild yeast IEC-ITV. The experiments were carried out al flask level using 20g/L xylose, 2g/L (NH₄)₂SO₄, 1g/L yeast extract, 5g/L KH₂PO₄ and 0.4 g/L MgSO4. To this medium were added 1,2 and 3g/L of acetic acid; 1 and 2 g/L of furfural and 0.05, 0.25 and 0.4g/L of 5-HMF in a separate way for each experiment. The inoculum was 3x10₆ cell/ml, culture conditions were 30 C, pH 5.5 and 250 rpm. Biomass was determined by dry weight, and xylose and xylitol by HPLC. Results showed that from 1 to 3g/L of acetic acid reduced the cellular growth 11% and the yield of xylitol in 37.5%, with a production of 6g/L of xylitol. For all concentrations of furfural there was a reduction of the cellular growth of the 48% and 31.5% the yield of xylitol, with a production of 5g/L. Respect to 5-HMF, there was an increase in the cellular growth of 22%, however it was shown a reduction of 50% of the yield, reaching only 8g/L of xylitol as compared to the fermentation in the absence of inhibitors. Significance: The wild strain yeast is not inhibited at 100% at the concentrations used in this work, which permits its application on production of xylitol from hydrolizates of sugar cane containing this inhibitors.

Session 36B, Biotechnology: General
8:30 AM - 12:00 PM, Monday AM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana