title: Regulation of poly(beta-hydroxybutyrate) synthesis in Methylobacterium rhodesianum MB 126 growing on methanol or fructose.
abstract: The intracellular concentration of CoA metabolites and nucleotides was determined in batch cultures of Methylobacterium rhodesianum grown on methanol and shifted to growth on fructose. The intracellular concentration of CoA decreased from a high value of 0.6 nmol/mg poly(beta-hydroxybutyrate)-free bacterial dry mass during growth on methanol to a low value of 0.03 nmol/mg poly(beta-hydroxybutyrate)-free bacterial dry mass after a shift to fructose as a carbon source. The levels of NADH, NADPH, and acetyl-CoA were also lower. Under these conditions, acetyl-CoA was metabolized by both citrate synthase and beta-ketothiolase, and poly(beta-hydroxybutyrate) synthesis and growth occurred simultaneously during growth on fructose. Moreover, the level of ATP was approximately 50% lower during growth on fructose, supporting the hypothesis of a bottleneck in the energy supply during the growth of M. rhodesianum with fructose.
authors.affiliation: Sächsisches Institut für Angewandte Biotechnologie (SIAB), Universität Leipzig, Permoserstrasse 15, D-04318 Leipzig, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Mothes
authors.forename: J U
authors.initials: JU
authors.lastname: Ackermann
authors.forename: W
authors.initials: W
authors.lastname: Babel
mesh_terms: D020155:3-Hydroxybutyric Acid; D000105:Acetyl Coenzyme A / Q000187:drug effects / Q000378:metabolism; D000102:Acetyl-CoA C-Acyltransferase / Q000187:drug effects / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000187:drug effects / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002950:Citrate (si)-Synthase / Q000187:drug effects / Q000378:metabolism; D003065:Coenzyme A / Q000187:drug effects / Q000378:metabolism; D003470:Culture Media / Q000494:pharmacology; D005632:Fructose / Q000494:pharmacology*; D016946:Gram-Negative Aerobic Rods and Cocci / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000378:metabolism*; D000432:Methanol / Q000494:pharmacology*; D009243:NAD / Q000187:drug effects / Q000378:metabolism; D009249:NADP / Q000187:drug effects / Q000378:metabolism; D012997:Solvents / Q000494:pharmacology*
chemical_list: D003470:Culture Media; D006885:Hydroxybutyrates; D012997:Solvents; D009243:NAD; D005632:Fructose; D000249:Adenosine Monophosphate; D009249:NADP; D000244:Adenosine Diphosphate; D000105:Acetyl Coenzyme A; D000255:Adenosine Triphosphate; D000429:Alcohol Oxidoreductases; C023744:acetoacetyl-CoA reductase; D000102:Acetyl-CoA C-Acyltransferase; D002950:Citrate (si)-Synthase; D003065:Coenzyme A; D020155:3-Hydroxybutyric Acid; D000432:Methanol