Browsing by Autor "Henrique Macedo Baudel"

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Arabinosylated phenolics obtained from SO<sub>2</sub>‐steam‐pretreated sugarcane bagasse
(Wiley, 2012) Cristhian Carrasco; Carlos Solano; J. Mauricio Peñarrieta; Henrique Macedo Baudel; Mats Galbe; Gunnar Lidén
Abstract A pentose‐rich hydrolysate fraction obtained by extraction of steam‐pretreated sugarcane bagasse was analysed with regard to dissolved phenolics. The liquid obtained after steam pretreatment (2% SO 2 (w/w) at 190 °C for 5 min) was divided into two parts: one containing dissolved compounds originating from hemicellulose (with xylose as the dominating compound), and the other containing predominantly dissolved compounds originating from lignin. Using nuclear magnetic resonance, the main dissolved compounds originating from lignin were identified as the glycosylated aromatics, 5‐ O ‐( trans ‐feruloyl)‐L‐Arabinofuranose and 5‐ O ‐( trans ‐coumaroyl)‐L‐Arabinofuranose, together with p ‐coumaric acid and small amounts of more common free phenolics such as p ‐hydroxybenzaldehyde, p ‐hydroxybenzoic acid and vanillin. The phenolic compounds were analysed and quantified using reversed‐phase high‐performance liquid chromatography. The findings show that SO 2 steam explosion opened up new degradation pathways during lignin degradation. Copyright © 2012 Society of Chemical Industry
Fermentation of the Straw Material Paja Brava by the Yeast &lt;i&gt;Pichia stipitis&lt;/i&gt; in a Simultaneous Saccharification and Fermentation Process
(Scientific Research Publishing, 2013) Cristhian Carrasco; Henrique Macedo Baudel; Christian Roslander; Mats Galbe; Gunnar Lidén
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%).
SO2-catalyzed steam pretreatment and fermentation of enzymatically hydrolyzed sugarcane bagasse
(Elsevier BV, 2009) Cristhian Carrasco; Henrique Macedo Baudel; Johan Sendelius; Tobias Modig; Christian Roslander; Mats Galbe; Bärbel Hahn‐Hägerdal; G. Zacchi; Gunnar Lidén
Steam pretreatment and fermentation of the straw material “Paja Brava” using simultaneous saccharification and co-fermentation
(Elsevier BV, 2010) Cristhian Carrasco; Henrique Macedo Baudel; J. Mauricio Peñarrieta; Carlos Solano; Leslie Tejeda; Christian Roslander; Mats Galbe; Gunnar Lidén