title: Shifting of the distribution of aromatic monomer-units in polyhydroxyalkanoic acid to longer units by salicylic acid in Pseudomonas fluorescens BM07 grown with mixtures of fructose and 11-phenoxyundecanoic acid.
abstract: Medium-chain-length-polyhydroxyalkanoic acids (MCL-PHAs) formed in Pseudomonas spp. have a rather broad distribution of monomer-units whose precursors are supplied via beta-oxidation degradation of MCL fatty acids fed as the carbon source and/or via PhaG enzyme catalyzing the acyl-group transfer from 3-hydroxyacyl-ACPs derived from acetyl-CoA to coenzyme A. It was found that salicylic acid (SA), in a concentration dependent manner, suppressed the accumulation of PHA in Pseudomonas fluorescens BM07 from fructose as well as shifted the distribution of monomer-units derived from a MCL fatty acid co-added as carbon source (e.g., 11-phenoxyundecanoic acid (11-POU)) to longer monomer-units. Both SA and acrylic acid were found to induce high accumulations of 3-ketohexanoic acid in BM07 wild-type cells grown with n-hexanoic acid as well as to inhibit the formation of acetyl-CoA from acetoacetyl-CoA by BM07 cell extract, suggesting that 3-ketoacyl-CoA thiolase is their common beta-oxidation target. The structural motif of acrylic acid present in the molecular structure of SA may self-explain the similar actions of the two inhibitors. A comparison of monomer modulation between BM07 wild-type and DeltaphaG mutant cells grown on the mixtures of fructose and 11-POU revealed that both PhaG and beta-oxidation inhibitor may play a critical role in the synthesis of PHA with longer side-chain omega-functional substitutions.
authors.affiliation: Nano-Biomaterials Science Laboratory, Division of Applied Life Sciences (BK21), Graduate School Gyeongsang National University, Jinju 660-701, South Korea.
authors.forename: Mun Hwan
authors.initials: MH
authors.lastname: Choi
authors.forename: Ju
authors.initials: J
authors.lastname: Xu
authors.forename: Jong Kook
authors.initials: JK
authors.lastname: Rho
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Shim
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Yoon
mesh_terms: D005227:Fatty Acids / Q000378:metabolism*; D005632:Fructose / Q000378:metabolism*; D054813:Polyhydroxyalkanoates / Q000096:biosynthesis* / Q000737:chemistry; D011551:Pseudomonas fluorescens / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D054813:Polyhydroxyalkanoates; D005632:Fructose; D020156:Salicylic Acid