Cloning and Expression of Clostridium acetobutylicum Endoglucanase, Cellobiase and Amino Acid Biosynthesis Genes in Escherichia coli

Clostridium acetobutylicum P262 endoglucanase and cellobiase genes, cloned on a 4·9 kb DNA fragment in the recombinant plasmid pHZ100, were expressed from their own promoter in Escherichia coli. Active carboxymethylcellulase and cellobiase enzymes were produced, but there was no degradation of Avicel. The endoglucanase activities observed in cell extracts of E. coli HB101(pHZ100) differed in their pH and temperature optima from those previously reported for C. acetobutylicum P270. Complementation of E. coli arg and his mutations by cloned C. acetobutylicum DNA was also observed.