BABET-REAL5 results presented at ENZITEC 2018
Also in South America, research results from the BABET-REAL5 project for a more sustainable bioethanol production were presented to the public. At the congress ENZITEC 2018, which was held from 16 to 19 September in Florianopolis, Brazil, Dr. Eleonora Campos presented results obtained in the laboratories of project partner INTA, Argentina.
Dr. Eleonora Campos from INTA presents research results at ENZITEC 2018
On 18 September 2018, Dr. Eleonora Campos presented results about improvements of bioconversion of extruded sweet corn cob at high solids consistency: Lignocellulosic biomass recalcitrance is based on the complex polymeric network of cellulose, hemicellulose and lignin that provides plants with strengh and resistance. For this reason, enzyme-mediated hydrolysis of lignocellulose, to release soluble and fermentable sugars, is a key step for lignocellulosic based biofuels. Xylan, the major hemicellulose component, is deconstructed by the action of xylanases (EC 188.8.131.52) and debranching enzymes. In this work, Eleonora Campos and colleagues evaluated the activity of a recombinant GH10 xylanase (XynA) from Paenibacillus sp A59, on sweet corn cob bioconversion. Sweet corn co-products (SCC) was pre-treated by a continuous alkaline thermo-mechano-chemical process, resulting in a composition of 42.1% cellulose, 26.6% hemicellulose and 6.4% lignin. Hydrolysis experiments were carried out with 20% solids load (g of dry biomass/ g total) using the highly active Cellic Ctec2 cocktail (Novozymes), at either 5 or 10 FPU/g, supplemented or not with XynA (100 IU/g). The hydrolysis configuration was determined based on the conditions for pre-hydrolysis and simultaneous saccharification and co-fermentation (PH-SSCF) (pH 5.5, 24h at 50°C followed by additional 48h at 30°C). From the 24h time point, a statistically significant increase of 1.1X in glucose and 1.3X xylose conversion was observed when XynA was added. By addition of XynA, final conversion levels resulted in over 80% for glucose and over 60% for hemicellulose. In conclusion, even though CCtec2 has high xylanase activity, addition of GH10-XynA resulted in higher conversion of extruded sweet corn cob to xylose and also glucose conversion. This could be explained by a higher deconstruction and accessibility of enzymes to fibers, which lead to a decrease in recalcitrance.
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