Author(s)

Cristhian Carrasco, Henrique Baudel, Christian Roslander, Mats Galbe, Gunnar Lidén

Department of Chemical Engineering, Federal University of Pernambuco, Recife, Brazil.
Department of Chemical Engineering, Lund University, Lund, Sweden.

Paja Brava is a native South American grass with a high carbohydrate content. In the current work, the potential of using this feedstock for ethanol production using a simultaneous saccharification and fermentation (SSF) process with the xylose-fermenting yeast Pichia stipitis (Scheffersomyces stipitis) CBS6054 was investigated. The straw material was subjected to SO₂ catalyzed steam pretreatment at 200°C and 5 min residence time, which resulted in a solubilization of pentose sugars (mainly xylose) of 64% with only minor amounts of degradation products. The obtained material, including the pretreatment liquid, was subsequently hydrolyzed and fermented in an SSF process at microaerobic conditions using either a batch or a fed-batch process at a total water-insoluble solids loading of 10%. Overall yields of ethanol based on all available sugars of 0.24 g/g and 0.27 g/g were obtained for batch and fed-batch mode of operation, respectively. The higher yield in the fed-batch process coincided with a higher degree of conversion of the sugars in the liquid medium, in particular of arabinose, for which the conversion was doubled (from 48% to 97%).

Ethanol; Lignocellulose; Fermentation; Xylose

Carrasco, C. , Baudel, H. , Roslander, C. , Galbe, M. and Lidén, G. (2013) Fermentation of the Straw Material Paja Brava by the Yeast Pichia stipitis in a Simultaneous Saccharification and Fermentation Process. Journal of Sustainable Bioenergy Systems, 3, 99-106. doi: 10.4236/jsbs.2013.32014.