| Title | Biological Pretreatment of Softwood Pinus densiflora by Three White Rot Fungi |
|---|---|
| Author | Jae-Won Lee1, Ki-Seob Gwak1, Jun-Yeong Park2, Don-Ha Choi3, Mi Kwon4, and In-Gyu Choi1* |
| Address | 1Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea, 2Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea, 3Department of Wood Chemistry and Microbiology, Korea Forest Research Institute, Seoul 130-712, Republic of Korea, 4Department of Forest Products, College of Forest Sciences, Kookmin University, Seoul 136-702, Republic of Korea |
| Bibliography | Journal of Microbiology, 45(6),485-491, 2007, |
| DOI | |
| Key Words | biological pretreatment, white rot fungi, enzymatic saccharification, woody biomass, ligninase, available pore size |
| Abstract | The effects of biological pretreatment on the Japanese red pine Pinus densiflora, was evaluated after exposure to three white rot fungi Ceriporia lacerata, Stereum hirsutum, and Polyporus brumalis. Change in chemical composition, structural modification, and their susceptibility to enzymatic saccharification in the degraded wood were analyzed. Of the three white rot fungi tested, S. hirsutum selectively degraded the lignin of this sortwood rather than the holocellulose component. After eight weeks of pretreatment with S. hirsutum, total weight loss was 10.7%, while lignin loss was the highest at 14.52% among the tested samples. However, holocellulose loss was lower at 7.81% compared to those of C. lacerata and P. brumalis. Extracelluar enzymes from S. hirsutum showed higher activity of ligninase and lower activity of cellulase than those from other white rot fungi. Thus, total weight loss and changes in chemical composition of the Japanese red pine was well correlated with the enzyme activities related with lignin- and cellulose degradation in these fungi. Based on the data obtained from analysis of physical characterization of degraded wood by X-ray Diffractometry (XRD) and pore size distribution, S. hirsutum was considered as an effective potential fungus for biological pretreatment. In particular, the increase of available pore size of over 120 nm in pretreated wood powder with S. hirsutum made enzymes accessible for further enzymatic saccharification. When Japanese red pine chips treated with S. hirsutum were enzymatically saccharified using commercial enzymes (Cellulclast 1.5 L and Novozyme 188), sugar yield was greatly increased (21.01%) compared to non-pretreated control samples, indicating that white rot fungus S. hirsutum provides an effective process in increasing sugar yield from woody biomass. |
| Download PDF | 45(6)_020.pdf |