skip to main content

Title: Adsorption of Clostridium thermocellum cellulases onto pretreated mixed hardwood, avicel, and lignin

Adsorption of Avicel-hydrolyzing activity was examined with respect to: mixed hardwood flour pretreated with 1% sulfuric acid for 9 s at 220C (PTW220), lignin prepared from PTW220 by either acid or enzymatic hydrolysis, and Avicel. Experiments were conducted at 60C for all materials, and also at 25C for PTW220. Based on transient adsorption results and reaction rates, times were selected at which to characterize adsorption at 60C as follows: PTW220, 1 min; lignin, 30 min; and Avicel, 45 min. Similar results were obtained for adsorption of cellulase activity to PTW220 at 25 and 60C, and for lignin prepared by enzymatic and acid hydrolysis. For all materials, adsorption was described well by a Langmuir equation, although the reversibility of adsorption was not investigated. Langmuir affinity constants (L/g) were: PTW220, 109; lignin, 17.9; Avicel, 4.3; cellulose from PTW220, [ge]187. Langmuir capacity constants were 760 for PTW220 and 42 for Avicel; the cellulase binding capacity of lignin appeared to be very high under the conditions examined, and could not be determined. At low and moderate cellulase loadings at least, the majority of cellulase activity adsorbed to PTVV220 is bound to the cellulosic component. The results indicate that PTW220, and its cellulose component inmore » particular, differ radically from Avicel with respect to adsorption. Avicel-hydrolyzing activity and CMC-hydrolyzing activities were found to bind to Avicel with a constant ratio of essentially one, consistent with adsorption of a multi-activity complex.« less
Authors:
; ; ;  [1]
  1. (Dartmouth College, Hanover, NH (United States). Thayer School of Engineering)
Publication Date:
OSTI Identifier:
6204399
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biotechnology and Bioengineering; (United States); Journal Volume: 42:7
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; CELLULASE; ENZYME ACTIVITY; CLOSTRIDIUM THERMOCELLUM; GROWTH; LIGNIN; ENZYMATIC HYDROLYSIS; ADSORPTION; BACTERIA; CARBOHYDRATES; CHEMICAL REACTIONS; CLOSTRIDIUM; DECOMPOSITION; ENZYMES; GLYCOSYL HYDROLASES; HYDROLASES; HYDROLYSIS; LYSIS; MICROORGANISMS; O-GLYCOSYL HYDROLASES; ORGANIC COMPOUNDS; POLYSACCHARIDES; PROTEINS; SACCHARIDES; SOLVOLYSIS; SORPTION 090900* -- Biomass Fuels-- Processing-- (1990-)