Submitted to: Federation of European Microbiological Societies Microbiology Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 20, 1998
Publication Date: N/A
Interpretive Summary: Successful exploitation of microorganisms in the bioconversion of agricultural commodities into valuable products requires an understanding of how these organisms control their metabolic processes. Many of these processes are regulated by internal chemical signals. One such signal involves the chemical, cyclic AMP (cAMP). We have been studying how one group of microorganisms that produces many valuable products regulates these processes. These organisms originate from environments lacking oxygen and are called anaerobes. In general, we have found that anaerobes do not make cAMP but have recently found one that does. In the current research, we have identified how this organism is able to do this. This information will help us to manipulate this organism to improve its performance in industrial fermentations and other applications.
Technical Abstract: Our previous evaluation of ruminal and other anaerobic bacteria showed only Prevotella ruminicola D31d produced detectable levels of cyclic AMP (cAMP). In order to confirm the presence of this important metabolic regulator, the gene for adenylate cyclase (cya), which enzymatically produces cAMP, was cloned and expressed in a cyaA mutant of Escherichia coli. The cloned P. ruminicola D31d was able to complement the cyaA mutation and allow for fermentation of maltose on MacConkey Lactose agar plates. Analyses of the DNA sequence of the 2.5-kilobase pair insert revealed an open reading frame encoding for a 67,000 MW protein. This protein was novel in that no amino acid similarity was observed with other procaryotic or eucaryotic adenylate cyclases in the GenBank database. Enzymatic production of cAMP in the E. coli clone was confirmed with a radioimmunoassay technique. This is the first example of an adenylate cyclase gene identified from an anaerobic bacterium.