(1) Department of Biochemistry and Cell Biology, MS 140, Rice University, 6100 Main Street, Houston, TX 77005, USA;(2) Present address: Dow Agrosciences LLC, R & D Discovery, 9330 Zionsville Road, Indianapolis, IN 46268, USA
Abstract:
The high solvent phenotype of Clostridium acetobutylicum mutants B and H was complemented by the introduction of a plasmid that contains either an intact or partially-deleted copy
of solR, restoring acetone and butanol production to wild-type levels. This demonstrates that the solR open reading frame on pSOLThi is not required to restore solvent levels. The promoter region upstream of alcohol dehydrogense
E (adhE) was examined in efforts to identify sites that play major roles in the control of expression. A series of adhE promoter fragments was constructed and the expression of each in acid- and solvent-phases of growth was analyzed using a
chloramphenicol acetyl-transferase reporter system. Our results show that a region beyond the 0A box is needed for full induction
of the promoter. Additionally, we show that the presence of sequences around a possible processing site designated S2 may
have a negative role in the regulation of adhE expression.