Liquefaction of sugarcane bagasse for enzyme production
Monday, April 28, 2014
Exhibit/Poster Hall, lower level (Hilton Clearwater Beach)
Fernanda Marisa Cunha1, Alberto Colli Badino2, Cristiane S. Farinas3, Thomas Kreke1, Eduardo Ximenes1 and Michael Ladisch1, (1)Laboratory of Renewable Resources Engineering, Purdue University, West Lafayette, IN, (2)Department of Chemical Engineering, Federal University of Sao Carlos, Sao Carlos, Brazil, (3)Brazilian Agricultural Research Corporation - Embrapa, São Carlos, Brazil
Bioprocessing of sugarcane bagasse to produce second generation (Gen 2) ethanol is carried out through a sequence of steps:  pretreatment, hydrolysis, and fermentation.  The localized nature of Brazilian ethanol facilities may benefit from on-site production of cellulase enzymes.  This has motivated research on cellulase production using a combination of solid state cultivation and submerged fermentation through Embrapa and UFSCar, at solids loadings of up to 30% w/volume, which may require significant power input in order to achieve adequate mixing during the aerated fermentations.  This work addresses enzyme induced liquefaction of sugarcane bagasse in a fed batch reactor based on addition of a cellulolytic strain of Aspergillus, discovered in the brazilian biome, that secretes cellulase, hemicellulases, and b-glucosidase when grown on sugarcane bagasse.  In this work Aspergillus niger A12 was initially incubated in solid-state cultivation 30% (w/w) for 72h at 32°C.  Suspensions of this material were mixed under fed-batch conditions with commercial available endoglucanase (301 IU per gram of dry solids) at 32°C and 50°C, pH 4.8, 290 rpm for 24 h and 48 h.  The solids fed-batch intervals were 0, 1, 2, 3, 6, 9 and 12h.  The material was liquefied after 48 hours, and the viscosity was slightly lower at 32°C than at 50°C (0.30 and 0.48 Pa.s, respectively, at 100 s-1 shear rate).  Effects of liquefaction on enzyme production by the Aspergillus sp is discussed, and impacts on enzyme titers compared to solid state fermentations, presented.