Effects of Additional Xylanase on Saccharification and Ethanol Fermentation of Ammonia-Pretreated Corn Stover and Rice Straw

Abstract

Synergistic effect of cellulase and hemicellulase (xylanase) was evaluated because lignocellulosic material is a heterogeneous complex of cellulose and hemicellulose. Various effects of HTec2 addition on enzymatic saccharification and fermentation were evaluated using two different substrates such as corn stover and rice straw. Corn stover and rice straw were pretreated by the LMAA (low-moisture anhydrous ammonia) method at the preselected same conditions (90 °C, 120 h, moisture content = 50%, NH3 loading = 0.1 g NH3/g). It was observed that the enzymatic saccharification yield of pretreated corn stover (76.4% for glucan digestibility) was higher than that of pretreated rice straw (70.9% for glucan) using CTec2 cellulase without HTec2 addition. Glucan digestibility of pretreated corn stover was significantly increased from 76.4% to 91.1% when the HTec2/CTec2 (v/v) increased from 0 to 10. However, it was interesting that the ethanol production was decreased from 89.9% to 76.3% for SSF and 118.0% to 87.9% for SSCF at higher HTec2/CTec2. As the glucan loading increased from 2.0% to 7.0%, the ethanol yields of both SSF and SSCF were decreased from 96.3% to 88.9% and from 116.6% to 92.4%, respectively. In addition, the smallest inoculum size (optical density of 0.25) resulted in the highest ethanol production (20.5 g/L).

Conversion of Lignocellulose for Bioethanol Production, Applied in Bio-Polyethylene Terephthalate

“…This finding implied that the SScF utilizing recombinant E. coli (K011) yielded more than 100% of the predicted maximal ethanol production based only on glucan. The results indicated that recombinant E. coli (K011) would efficiently consume glucose and xylose and convert them to ethanol [ 137 ].…”

Conversion of Wheat Bran to Xylanases and Dye Adsorbent by Streptomyces thermocarboxydus

“…Among them, endo-xylanase, and exo-xylanase are the most important contributors to xylan depolymerization. Until now, vast applications of xylanase have been extensively explored based on its ability in xylan degradation, for example, biofuels production [ 6 , 7 , 8 ], pulp and paper bleaching [ 9 , 10 , 11 ], bioactive compounds [ 12 , 13 , 14 ], animal feed [ 15 , 16 ], and baking [ 17 , 18 , 19 ].…”