Production of cellulase enzymes and hydrolysis of steam-exploded wood

Journal Article · Tue Apr 01 04:00:00 EST 1986 · Biotechnol. Bioeng.; (United States)

DOI:https://doi.org/10.1002/bit.260280413· OSTI ID:5367423

San Martin, R; Blanch, H W; Wilke, C R; Sciamanna, A F

Steam-exploded aspen has been examined as a candidate feedstock for both cellulase production and enzymatic hydrolysis of wood. Batch and fed-batch cultivation methods were evaluated and compared with previous experiments using ball-milled, crystalline cellulose (Solka Floc). Batch cultivation of Trichoderma reesei Rut C-30 on 9 wt% water-washed aspen yielded enzyme productivities and activities comparable to those obtained on Solka Floc (40 FP IU/l-h; 7.5 FP IU/ml). Fed-batch cultivation of Rut C-30 resulted in higher enzyme productivities and titers than batch cultivation (50 FP IU/l-h; 15 FP IU/ml). However, the overall enzyme production performance was lower than Solka Floc at comparable cellulose feeding rates and concentrations. This may be due to the accumulation of steam explosion by-products and lignin in the fermentor. The hydrolysis of water-washed steam-exploded aspen was performed at different enzyme loading and wood concentrations. Glucose production, using 10 and 15 wt% suspension, showed that while glucose concentration increased with wood load, the yield of glucose derived from cellulose decreased. With 10 wt% suspensions, it was possible to obtain a cellulose conversion to glucose above 95%. Low cellobiose levels in the hydrolyzates indicated that the enzyme preparations have ..beta..-glucosidase to filter paper activity ratios (approximately 1.5), a significant result since the fungus was grown exclusively on wood. It also suggested that the observed yield decrease is more likly to be caused by glucose than cellobiose inhibition of the enzymes. 9 references.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 5367423
• Journal Information: Biotechnol. Bioeng.; (United States), Journal Name: Biotechnol. Bioeng.; (United States) Vol. 28:4; ISSN BIBIA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
ASPENS
BATCH CULTURE
BIOREACTORS
BIOSYNTHESIS
CARBOHYDRATES
CELLULASE
CELLULOSE
CHEMICAL REACTIONS
DECOMPOSITION
ENZYMATIC HYDROLYSIS
ENZYME ACTIVITY
ENZYMES
FUNGI
GLUCOSE
GLYCOSYL HYDROLASES
HEAT TREATMENTS
HEXOSES
HYDROLASES
HYDROLYSIS
LOADING RATE
LYSIS
MONOSACCHARIDES
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
PRODUCTION
SACCHARIDES
SEMIBATCH CULTURE
SOLVOLYSIS
STEAM
SYNTHESIS
TREES
TRICHODERMA
TRICHODERMA VIRIDE
WOOD