Long & Medium-Term Research: Metabolic Engineering of Anaerobes This award through the Program for Long & Medium-Term Research at Foreign Centers of Excellence, which enables U.S. postdoctoral researchers to conduct 3 to 12 months joint research abroad at centers of proven excellence, where researchers can profit from unique or complementary facilities, expertise and experimental conditions abroad. This award will support a 12-month postdoctoral research visit by Dr. D.J. Petersen with Professor Jos Vanderleyden of the F.A. Janssenslaboratorium voor Genetics, Katholieke Universiteit Leuven ?Louvaine!, Belgium. Thanks to biotech- nology, which now can dramatically change the metabolic character of micro rganisms, the anaerobic organism Clostridium acetobutylicum is used commercially to produce important organic solvents because it can convert a wide variety of crude substrates to acids and alcohols in high yield. New knowledge concerning the molecular genetics and cell regulation of C. acetobutylicum allows unprecedented genetic manipulation of fermentations of this organism. Dr. Petersen proposes to produce beneficial genetic alterations of the cell metabolism by the introduction and amplification of modified genes to (1) elucidate the regulatory factor(s) controlling the metabolic switch from acid to solvent production; (2) produce specific alterations to place expression of genes involved in solvent production under regulatory controls independent of cell cycle, including site-specific mutagenesis and recombination with altered genes; (3) identify the solvent induction signal, facilitated by Tn916 mutants already achieved in his laboratory; 4) analyze transcription regulation with the newly developed ELISA system which increases sensitivity and reproductibility while circumventing problems inherent in anaerobic - galactosidase assays using C. acetobutylicum; 5) incorporate anti-sense RNA technology also developed by Dr. Vanderleyden in the bioreactor studies of gene regulations in genetically altered strains; 6) evaluate cells metabolically with altered enzymatic pathways to assess the effectiveness of recombinant proteins in biocatalysis and observe the effects on the levels of other enzymes; 7) study research developments at Leuven in gene transfer technology with other model systems such as Azospirillum and Rhizobia. The award recommendation provides funds to cover international travel and a dependent's allowance.
