Contrasting effects of hardwood and softwood organosolv lignins on enzymatic hydrolysis of lignocellulose.
Identifying an appropriate parameter to elucidate effects of lignin on enzymatic hydrolysis is essential to understand the interactions between enzymes and lignin. Contrasting effects of hardwood organosolv lignin (EOL-SG) and softwood organosolv lignin (EOL-LP) on enzymatic hydrolysis were observed. The addition of EOL-SG (8 g/L) significantly improved the 72 h hydrolysis yields of organosolv pretreated sweetgum (OPSG) and loblolly pine (OPLP) from 49.3% to 68.6% and from 41.2% to 60.8%, respectively. In contrast, the addition of EOL-LP decreased the 72 h hydrolysis yields of OPSG and OPLP to 42.0% and 38.1%, respectively. A strong correlation between the distribution coefficients of cellulase enzymes on lignins and the changes of hydrolysis yields indicated that the inhibitory or stimulatory effects of organosolv lignins on enzymatic hydrolysis were governed by the distribution coefficients (R). The different R values probably were related to the electrostatic interactions, hydrophobic interactions and hydrogen bondings between enzymes and lignin.
College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing, Jiangsu 210037, China; Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States.
Chenhuan
C
Lai
Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States. Electronic address: mtu@auburn.edu.
Maobing
M
Tu
Forest Products Laboratory and Center for Bioenergy and Bioproducts, Auburn University, 520 Devall Drive, Auburn, AL 36849, United States.
Zhiqiang
Z
Shi
College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing, Jiangsu 210037, China.
Ke
K
Zheng
Department of Chemical and Natural Gas Engineering, Texas A&M University, 700 University Blvd, Kingsville, TX 78363, United States.
Luis G
LG
Olmos
College of Chemical Engineering, Nanjing Forestry University, 159 Longpan Road, Nanjing, Jiangsu 210037, China.
Shiyuan
S
Yu
D002480:Cellulase / Q000378:metabolism*; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D008031:Lignin / Q000378:metabolism*; D066244:Proton Magnetic Resonance Spectroscopy; D014934:Wood
C036909:lignocellulose; D008031:Lignin; D002480:Cellulase
Enzymatic hydrolysis; Enzyme distribution; Ethanol organosolv lignin; Langmuir adsorption isotherm