%0 Journal Article
	%A S. C. Santos and  S. R. Dionísio and  A. L. D. De Andrade and  L. R. Roque and  A. C. Da Costa and  J. L. Ienczak
	%D 2015
	%J International Journal of Biotechnology and Bioengineering
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 101, 2015
	%T Fermentation of Xylose and Glucose Mixture in Intensified Reactors by Scheffersomyces stipitis to Produce Ethanol
	%U https://publications.waset.org/pdf/10001459
	%V 101
	%X In this work, two fermentations at different
temperatures (25 and 30ºC), with cell recycling, were accomplished
to produce ethanol, using a mix of commercial substrates, xylose
(70%) and glucose (30%), as organic source for Scheffersomyces
stipitis. Five consecutive fermentations of 80 g L-1 (1º, 2º and 3º
recycles), 96 g L-1 (4º recycle) and 120 g L-1 (5º recycle)reduced
sugars led to a final maximum ethanol concentration of 17.2 and 34.5
g L-1, at 25 and 30ºC, respectively. Glucose was the preferred
substrate; moreover xylose startup degradation was initiated after a
remaining glucose presence in the medium. Results showed that yeast
acid treatment, performed before each cycle, provided improvements
on cell viability, accompanied by ethanol productivity of 2.16 g L-1 h-
1 at 30ºC. A maximum 36% of xylose was retained in the
fermentation medium and after five-cycle fermentation an ethanol
yield of 0.43 g ethanol/g sugars was observed. S. stipitis fermentation
capacity and tolerance showed better results at 30ºC with 83.4% of
theoretical yield referenced on initial biomass.
	%P 539 - 544