S197: Potential for Production of Metabolites by Alicyclobacillus acidocaldarius

Alicyclobacillus acidocaldarius is a Gram-positive thermoacidophile capable of growth on a range of sugar monomers as well as oligo- and poly-saccharides.  The recent sequencing of the A. acidocaldarius genome has shown genes for a variety of intermediary metabolisms, including those for lactate, acetate, succinate and ethanol.  A metabolic model for A. acidocaldarius was constructed using the genome information, and tested using elementary flux mode analysis.  Model testing indicated that A. acidocaldarius may be able to grow anaerobically when specific enzymes are expressed leading to the production of organic acids and alcohols as electron sinks.  This finding is interesting considering A. acidocaldarius has been classified as an obligate aerobe.  Continuous-flow chemostat studies demonstrated A. acidocaldarius was able to produce lactate, succinate, acetate, formate, and traces of ethanol when grown on either xylose or glucose, as the sole source of carbon and energy.  Growing A. acidocaldarius under nitrogen-limited conditions did not appear to increase organic acid or alcohol production significantly.   These preliminary metabolite production results for A. acidocaldarius suggest a flexible metabolism with potential for biotechnological applications.