title: Conversion of lignin model compounds by Pseudomonas putida KT2440 and isolates from compost.
abstract: Starting from mature vegetable compost, four bacterial strains were selected using a lignin-rich medium. 16S ribosomal RNA identification of the isolates showed high score similarity with Pseudomonas spp. for three out of four isolates. Further characterization of growth on mixtures of six selected lignin model compounds (vanillin, vanillate, 4-hydroxybenzoate, p-coumarate, benzoate, and ferulate) was carried out with three of the Pseudomonas isolates and in addition with the strain Pseudomonas putida KT2440 from a culture collection. The specific growth rates on benzoate, p-coumarate, and 4-hydroxybenzoate were considerably higher (0.26-0.27 h-1) than those on ferulate and vanillate (0.21 and 0.22 h-1), as were the uptake rates. There was no direct growth of P. putida KT2440 on vanillin, but instead, vanillin was rapidly converted into vanillate at a rate of 4.87 mmol (gCDWh)-1after which the accumulated vanillate was taken up. The growth curve reflected a diauxic growth when mixtures of the model compounds were used as carbon source. Vanillin, 4-hydroxybenzoate, and benzoate were preferentially consumed first, whereas ferulate was always the last substrate to be taken in. These results contribute to a better understanding of the aromatic metabolism of P. putida in terms of growth and uptake rates, which will be helpful for the utilization of these bacteria as cell factories for upgrading lignin-derived mixtures of aromatic molecules.
authors.affiliation: Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden.
authors.forename: Krithika
authors.initials: K
authors.lastname: Ravi
authors.affiliation: Department of Chemistry, Applied Microbiology, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden. javier.garcia_hidalgo@tmb.lth.se.
authors.forename: Javier
authors.initials: J
authors.lastname: García-Hidalgo
authors.affiliation: Department of Chemistry, Applied Microbiology, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden.
authors.forename: Marie F
authors.initials: MF
authors.lastname: Gorwa-Grauslund
authors.affiliation: Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00, Lund, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Lidén
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D001547:Benzaldehydes / Q000378:metabolism / Q000494:pharmacology; D001565:Benzoates / Q000494:pharmacology; D000076282:Composting; D003373:Coumaric Acids / Q000737:chemistry / Q000494:pharmacology; D003470:Culture Media / Q000737:chemistry; D005798:Genes, Bacterial; D008031:Lignin / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D010226:Parabens / Q000494:pharmacology; D016958:Pseudomonas putida / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S
chemical_list: D001426:Bacterial Proteins; D001547:Benzaldehydes; D001565:Benzoates; D003373:Coumaric Acids; D003470:Culture Media; D010226:Parabens; D012336:RNA, Ribosomal, 16S; D008031:Lignin; C004999:ferulic acid; C100058:vanillin; C038193:4-hydroxybenzoic acid
keywords: Aromatic compound conversion; Bacterial metabolism; Compost; Lignin; Pseudomonas