Effect of carbon source on the expression of celA1, a cellulase-encoding gene from Streptomyces halstedii JM8

The production of the cellulase Cell from Streptomyces halstedii JM8 was studied in cells grown in the presence of glucose, cellobiose or microcrystalline cellulose (Avicel). Among these, glucose repressed expression while cellobiose and Avicel exerted a clear induction. The gene celA1 was cloned in several heterologous Streptomyces hosts and its expression analyzed. S. parvulus transformed with the plasmid pJM11, a pIJ702 derivative, was the best producer. A region which includes the sequence ATTGGGACCGCTTCC located between positions -161 and -147 upstream from the translation initiation codon [Fernández-Abalos et al. (1992) J. Bacteriol. 174, 6368-6376] was deleted and its effect was studied in the presence of different carbon sources. Although the observed effect depends on the host used, this region seems to be involved in activation of the expression of this gene.