Sunday, May 4, 2008
3-70
Study on Biomass Biodegradation by White Rot Fungi for Fuel Ethanol Production
Xiaoyu Zhang Sr., Chunyan Xu, and Hongbo Yu. Department of Biotechnology, College of Life Science and Technology, Huazhong University of Science & Technology, P.R. China, Wuhan, China
The process and mechanisms of biodegradation by white-rot fungi were evaluated by studying the relations between biodegradation of biomass by white-rot fungi and releasing of substrates for fuel ethanol production.
According to growth characteristics, laccase activity and degradation capability, two fungi, Echinodontium taxodii Et and Pleurotus ostreatusPo , were screened from 268 strains of Basidiomycetes. E. taxodii Et is a typical white-rot fungus with selective degradation and P. ostreatus Po is a typical fungus which could degrade lignocelluloses effectively.
Biodegradation of E. taxodii Et and P. ostreatus Po were investigated in natural lignocelluloses medium, the results showed that hemicellulose and lignin were degraded firstly by the two fungi. The degradation rate of cellulose improved gradually with increasing of incubation time. Compared to the control sample, after pretreated with E. taxodii Et, the saccharification rate of corn stalk and bamboo increased by 53.8% and 39.3%, respectively. The pretreatment model was established by combining biological pretreatment with alkali treatment. In this model, the saccharification rate of biomass could reach 71.7% and the cellulase dosage was 20% of cellulase amount used for control sample.
Lignin biodegradation by E. taxodii Et was the key of cellulose releasing and weakening resistance to cellulase, which could destroy physical barrier of biomass, accelerate releasing of cellulose, decrease unproductive enzyme adsorption, weaken the resistance of biomass to cellulase and decrease the used dosage of cellulase. These findings provided new theoretical support and technical methods for pretreating biomass with low cost and energy to obtain biological fuel.
According to growth characteristics, laccase activity and degradation capability, two fungi, Echinodontium taxodii Et and Pleurotus ostreatus
Biodegradation of E. taxodii Et and P. ostreatus Po were investigated in natural lignocelluloses medium, the results showed that hemicellulose and lignin were degraded firstly by the two fungi. The degradation rate of cellulose improved gradually with increasing of incubation time. Compared to the control sample, after pretreated with E. taxodii Et, the saccharification rate of corn stalk and bamboo increased by 53.8% and 39.3%, respectively. The pretreatment model was established by combining biological pretreatment with alkali treatment. In this model, the saccharification rate of biomass could reach 71.7% and the cellulase dosage was 20% of cellulase amount used for control sample.
Lignin biodegradation by E. taxodii Et was the key of cellulose releasing and weakening resistance to cellulase, which could destroy physical barrier of biomass, accelerate releasing of cellulose, decrease unproductive enzyme adsorption, weaken the resistance of biomass to cellulase and decrease the used dosage of cellulase. These findings provided new theoretical support and technical methods for pretreating biomass with low cost and energy to obtain biological fuel.
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See more of The 30th Symposium on Biotechnology for Fuels and Chemicals (May 4 -- 7, 2008)
See more of General Submissions
See more of The 30th Symposium on Biotechnology for Fuels and Chemicals (May 4 -- 7, 2008)