Mutational analysis of \beta-glucoside utilization in Klebsiella aerogenes: evidence for the presence of multiple genetic systems

Escherichia coli possesses multiple systems for uptake and utilization of the \beta-glucoside sugars salicin, arbutin and cellobiose. However, these genes are not expressed in the wild-type organism. Activating mutations at three different loci, the bgl operon, the cel operon, and the asc system, enable E. coli to utilize these sugars (see Mukerji and Mahadevan 1997 for a review). Of the three, the bgl operon, involved in uptake and degradation of the aromatic \beta-glucosides arbutin and salicin, is best characterized (Prasad and Schaefler 1974; Reynolds et al. 1981; Mahadevan et al. 1987; Schnetz and Rak 1987)