title: Hydroxy-fatty acid production in a Pseudomonas aeruginosa 42A2 PHA synthase mutant generated by directed mutagenesis.
abstract: Pseudomonas aeruginosa 42A2 growing on waste frying oils is capable to synthesize polyhydroxyalkanoic acids (PHAs) and hydroxy-fatty acids as a result of several enzymatic conversions. In order to study the physiological role of PHA biosynthesis in P. aeruginosa with respect to the synthesis of hydroxy-fatty acids, an unmarked deletion mutant deficient for PHA biosynthesis was generated in P. aeruginosa 42A2. A combination of the sacB-based negative selection system with a cre-lox antibiotic marker recycling method was used for mutant isolation. Electron microscopy, nuclear magnetic resonance analysis, and transmission electron microscopy confirmed that PHA accumulation was completely abolished in the mutant strain. Interestingly, the new mutant strain showed higher carbon and oxygen uptake rate than the wild-type strain and higher efficiency in the conversion of oleic acid into (E)-10-hydroxy-8-octadecenic acid-octadecenoic acid.
authors.affiliation: Department of Microbiology, Faculty of Biology, University of Barcelona, Barcelona, Spain.
authors.forename: Noelia
authors.initials: N
authors.lastname: Torrego-Solana
authors.forename: Ignacio
authors.initials: I
authors.lastname: Martin-Arjol
authors.forename: Mònica
authors.initials: M
authors.lastname: Bassas-Galia
authors.forename: Pilar
authors.initials: P
authors.lastname: Diaz
authors.forename: Angeles
authors.initials: A
authors.lastname: Manresa
mesh_terms: D000217:Acyltransferases / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D005227:Fatty Acids / Q000096:biosynthesis*; D016297:Mutagenesis, Site-Directed; D054813:Polyhydroxyalkanoates / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids; D054813:Polyhydroxyalkanoates; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase