Effect of Commercial Cellulase Enzymes on Ethanol Production from Pretreated Rice Straw at High Solid Loading

Abstract

Effect of commercial cellulose enzymes was investigated by batch enzymatic hydrolysis at 15.0% (w/v) solid. It was found that the best commercial cellulose enzyme was Cellic ® CTec comparing to Accellerase 1000 TM and Accelerase 1500 TM . The Cellic ® CTec gave the highest reducing sugar concentration and rice straw conversion. Moreover, when the hydrolysate obtained from hydrolysis using Cellic ® CTec was fermented by Saccharomyces cerevisiae TISTR 5596, it would give the highest ethanol. In this study, the Cellic ® CTec was used for fed-batch prehydrolysis prior to ethanol production by simultaneous saccharification and fermentation (SSF) way at 20% (w/v) solid loading. It could produce 35.76 g/L or 4.6% (v/v) of ethanol concentration and 83.67 L/ton dry matter (DM) of yield.

Enhancing Hydrogen Production from Chlorella sp. Biomass by Pre-Hydrolysis with Simultaneous Saccharification and Fermentation (PSSF)

“…This phenomenon was also observed for other strains of microalgae, e.g., suspensions of Nanochloropsis salina in a range of 9.74-24.01% total solids [47] and Scenedesmus obliquus in a range of 0-150 g L −1 [48]. The increased viscosity could result in insufficient mixing and heat transfer, the reduction in water availability, and the irreversible binding of enzymes to the substrate [49]. These adversely affected bacterial growth and, consequently, hydrogen production [50].…”

Insight into pathway of monosaccharide production from integrated enzymatic hydrolysis of rice straw waste as feed stock for anaerobic digestion

“…74 °C, sample temp. 70 °C, 350 psi, 20 min Enzymatic hydrolysis, 50ºC, 15 min – 72 h AFEX-pretreated rice straw gave higher carbohydrates conversion Xylose was a significant part (69–70%) followed by arabinose and glucose (20–24%) for AFEX Vlasenko et al 32 Cellucalast 1.5L Novozym 188 Acid pre-treatment, 160-180ºC followed by enzymatic hydrolysis, 50ºC, 72 h Glucose and xylose release about 83% of the sugar content in the raw material Hsu et al 14 Cellulase enzyme from Genencor International, UAS Dilute H 2 SO 4 , 20 min followed by enzymatic hydrolysis, 50ºC, 60 h Total yield of glucose was about 76% of glucose in the raw material Wei et al 33 Cellic Ctec Accelerase 1000TM Accelerase 1500 TM H 2 SO 4 , 121ºC, 15 min followed by enzymatic hydrolysis, 50ºC, 72 h The highest sugar and ethanol production was found from the using of Cellic Ctec cellulase Srinorakutara et al 34 Cellulase and laccase enzyme produced from microbial culture Nitric acid pre-treatment, 160-180ºC followed by microbial degradation at 30ºC, 72 h An increase in glucose amount in the supernatant was 29.13% as compared to the control samples Chownk et al 35 Cocktails of immobilized enzymes (Celluclast 1.5L, BGL, and laccase) Dilute sulfuric acid pre-treatment, 121 ºC followed by immobilized enzymatic hydrolysis, 35-55ºC, 48 h Sugar yields were in the range of 53–67% with acid concentration from 0.1% to 1.0% H2SO4 Kumar et al 36 Cellulase enzyme from Aspergillus Niger Atres Zymix Plus (Atres group, Germany) Different integrated enzyme hydrolysis approaches: Dilute H 2 SO 4 , room temp, 4 h Dilute NaOH, room temp, 4 h Boiled water, 4 h Combined with Enzymatic hydrolysis, 50-55ºC, 48 h Boiled rice straw followed by enzymatic hydrolysis gave the highest monosaccharide yield in the digestate Glucose was the significant part (78–86%) of the monosaccharides This study …”