EFFECT OF CARBON SOURCE ON THE EXPRESSION OF CELA(1), A CELLULASE-ENCODING GENE FROM STREPTOMYCES-HALSTEDII JM8

The production of the cellulase Cell from Streptomyces halstedii JM8 w as studied in cells grown in the presence of glucose, cellobiose or mi crocrystalline cellulose (Avicel). Among these, glucose repressed expr ession while cellobiose and Avicel exerted a clear induction. The gene celA(1) 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 t he sequence ATTGGGACCGCTTCC located between positions -161 and -147 up stream from the translation initiation codon [Fernandez-Abalos et al. (1992) J. Bacteriol. 174, 6368-6376] was deleted and its effect was st udied in the presence of different carbon sources, Although the observ ed effect depends on the host used, this region seems to be involved i n activation of the expression of this gene.