ETHANOL PRODUCTION AND SUGAR CONSUMPTION OF CO-CULTURE Saccharomyces cerevisiae FNCC 3012 WITH Candida tropicalis FNCC 3033 IN MEDIA CONTAINING INHIBITOR FERMENTATION

Abstract

Inhibitor fermentation is one of the problems that arise in the ethanol production from lignocellulose waste. This work examined the ethanol yield and sugar consumption of mono and co-culture S. cerevisiae with C. tropicalis in media containing inhibitor fermentation. Furfural and phenol were used for inhibitor fermentation in basal medium with concentrations of 2.0 and 5.0 %, respectively. The basal medium contained 20 g.L-1 glucose, 20 g.L-1 D (+) xylose, 20 g.L-1 arabinose, 4 g.L-1 urea, 3 g.L-1 NaNO3, 3 g.L-1 NH4NO3, 1 g.L-1 KH3PO4 and 0.7 g.L-1 MgSO4·7H2O with pH adjusted to 5.5 with 1 mol.L-1 HCl. After furfural or phenol addition separately, and inoculation by mono and co-culture S. cerevisiae FNCC 3012 with C. tropicalis FNCC 3033, all media were incubated at 28–29 °C, 50% r.h. in the dark for 5 days in a rotary incubator at 60 rev/min. We found yeast colony count, sugar consumption, ethanol yields and efficiency of fermentation by co-culture S. cerevisiae with C. tropicalis higher than mono-culture S. cerevisiae or C.tropicalis in the fermentation media with or without inhibitors. This work indicated that co-culture S. cerevisiae with C. tropicalis were more tolerant to furfural and phenol. Ethanol yield 8.52%, 5.37% and 3.83% obtained from basal medium, basal medium plus 2.5 or 5.0 % furfural, respectively and efficiency of fermentation 27.00%, 17.00% and 12.20%. Ethanol yields 8.13%, 5.62% and 3.19% obtained from basal medium, basal medium plus 2.5 or 5.0 % phenol, respectvely and efficiency of fermentation 28.20%, 20.00% and 14.00%. Co-culture S. cerevisiae FNCC 3012 with C. tropicalis 3033 demonstrated potential as a fermentation process for ethanol production from lignocellulosic media content inhibitors. The use of this co-culture effectively utilizes hexose and pentose sugars in the substrate, increasing the yield and efficiency of fermentation for ethanol production.