title: Production of D-(--)-3-hydroxyalkanoic acid by recombinant Escherichia coli.
abstract: Pathways for extracellular production of chiral D-(-)-3-hydroxybutyric acid (3HB) and D-(-)-3-hydroxyalkanoic acid (mcl-3HA) were constructed by co-expression of genes of beta-ketothiolase (phbA), acetoacetyl-CoA reductase (phbB) and 3-hydroxyacyl-ACP CoA transacylase (phaG), respectively, in Escherichia coli strain DH5alpha. The effect of acrylic acid and glucose on production of both 3HB and mcl-3HA was investigated. It was found that the addition of acrylic acid significantly increased production of 3HB and mcl-3HA consisting of 3-hydroxyoctanoic acid and 3-hydroxydecanoic acid in a ratio of 1:3 from 199 mg x l(-1) to 661 mg x l(-1) and from 27 mg x l(-1) to 135 mg x l(-1), respectively, in shake flask studies when glucose was present in the medium at the very beginning of fermentation. The timing of glucose addition had no effect on 3HB production. In contrast, mcl-3HA production was affected by glucose addition, an mcl-3HA concentration of 193 mg x l(-1) was obtained when glucose was added to the culture at 12 h. A more than seven-fold increase was obtained when compared with that in medium containing glucose at the beginning of fermentation. However, a decrease in production of 3HB and mcl-3HA was found when glucose was added at 12 h to the culture containing acrylic acid. The repressive effect of acrylic acid on acetic acid production was also evaluated and discussed.
authors.affiliation: Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing 100084, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Zhao
authors.forename: Ge
authors.initials: G
authors.lastname: Tian
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zheng
authors.forename: Jin-Chun
authors.initials: JC
authors.lastname: Chen
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Chen
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000378:metabolism*; D000102:Acetyl-CoA C-Acyltransferase / Q000235:genetics / Q000378:metabolism; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D002210:Caprylates / Q000378:metabolism*; D003652:Decanoic Acids / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D002210:Caprylates; D003652:Decanoic Acids; D011994:Recombinant Proteins; C101940:3-hydroxyoctanoic acid; D000429:Alcohol Oxidoreductases; C023744:acetoacetyl-CoA reductase; D000217:Acyltransferases; C114682:3-hydroxyacyl-CoA-acyl carrier protein transferase; D000102:Acetyl-CoA C-Acyltransferase; C017552:myrmicacin; D020155:3-Hydroxybutyric Acid