BIOETHANOL PRODUCTION FROM Agave lechuguilla BIOMASS PRETREATED BY AUTOHYDROLYSIS

 

O.H. Ortíz-Méndez, T.K. Morales-Martínez, L.J. Rios-González, J.A. Rodríguez-de la Garza, J. Quintero, G. Aroca

 

 

Agave lechuguilla cogollos (heart or pulpy central stem with attached leaf bases) were used as feedstock for production of second generation bioethanol following a scheme based on pretreatment by autohydrolysis, enzymatic saccharification and fermentation of hydrolysates. Autohydrolysis was carried out in a Parr reactor at different severity factors with a solid/liquid ratio of 1/6 (w/v) and 200 rpm. Solid fraction obtained was hydrolyzed using the commercial cellulase Accellerase 1500 (Genencor®). Hydrolysate was fermented with the Saccharomyces cerevisiae ATCC 4126 yeast. Using a severity factor of 4.127 (190 °C during 30 min) it was possible to preserve most of the glucans while increasing its enzymatic digestibility. Enzymatic hydrolysis of the solid fraction showed a maximum yield of 60.85%, with a final glucose concentration of 59 g/L. Ethanol concentration at the end of the fermentation was 25.4 g/L (91% of the theoretical ethanol yield).