Addition of cloned beta-glucosidase enhances the degradation of crystalline cellulose by the Clostridium thermocellum cellulose complex.
A thermostable beta-glucosidase from Clostridium thermocellum which is expressed in Escherichia coli was used to determine the substrate specificity of the enzyme. A restriction map of the beta-glucosidase gene cloned in plasmid pALD7 was determined. Addition of the E. coli cell extract (containing the beta-glucosidase) to the cellulase complex from C. thermocellum increased the conversion of crystalline cellulose (Avicel) to glucose. The increase was specifically due to hydrolysis of the accumulated cellobiose. A cellulose degradation process using beta-glucosidase to assist the potent cellulase complex of C. thermocellum, as shown here can open the way for industrial saccharification of cellulose to glucose.
Kadam
S K
SK
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Demain
A L
AL
D002480:Cellulase / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D003001:Cloning, Molecular; D003013:Clostridium / Q000201:enzymology*; D004926:Escherichia coli; D005959:Glucosidases / Q000378:metabolism*; D007700:Kinetics; D010957:Plasmids; D015183:Restriction Mapping; D013379:Substrate Specificity; D001617:beta-Glucosidase / Q000235:genetics / Q000378:metabolism*
D002482:Cellulose; D005959:Glucosidases; D001617:beta-Glucosidase; D002480:Cellulase