Identification of novel sulfur-containing bacterial polyesters: biosynthesis of poly(3-hydroxy-S-propyl-omega-thioalkanoates) containing thioether linkages in the side chains.
This study describes the biosynthesis of novel sulfur-containing polyhydroxyalkanoates (PHAs), which consist exclusively of hydroxypropylthioalkanoic acid containing thioether groups in the side chains. In addition, the utilization of alkylthioalkanoic acids (=thia fatty acids) by various bacteria was investigated. Based on feedings with propylthiooctanoic acid (PTO) or propylthiohexanoic acid, the metabolically engineered PHA-negative mutant PHB(-)4 of Ralstonia eutropha, which harbours plasmid pBBR1::phaC1 expressing the PHA synthase of Pseudomonas mendocina, synthesized two novel poly(3-hydroxy-S-propyl-omega-thioalkanoic) acids [poly(3HPTA)s]. A terpolyester consisting of 3-hydroxypropylthiobutyric acid (3HPTB), 3-hydroxypropylthiohexanoic acid (3HPTHx) and 3-hydroxypropyl- thiooctanoic acid (3HPTO) was synthesized from PTO, whereas a co-polyester of 3HPTB and 3HPTHx was synthesized from propylthiohexanoic acid. Fed-batch fermentation of R. eutropha PHB(-)4(pBBR1::phaC1) on PTO was done on a 26-litre scale, providing a cell density of 7.3 g l(-1), from which 45 g of the novel poly(3HPTB-co-3HPTHx-co-3HPTO) were isolated. The chemical structures of the poly(3HPTA)s were identified by gas chromatography/mass spectrometry, elemental sulfur analysis, partial pyrolysis and detailed mass spectrometric analysis, exhibiting 3HPTB, 3HPTHx and 3HPTO as constituents. These novel, hitherto undescribed, constituents of PHAs were randomly distributed in the co-polyesters.
Ewering
Christian
C
Institut für Mikrobiologie, Westfälische Wilhelms-Universität Münster, Corrensstraße 3, D-48149 Münster, Germany1.
Lütke-Eversloh
Tina
T
Institut für Mikrobiologie, Westfälische Wilhelms-Universität Münster, Corrensstraße 3, D-48149 Münster, Germany1.
Luftmann
Heinrich
H
Institut für Organische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, D-48149 Münster, Germany2.
Steinbüchel
Alexander
A
Institut für Mikrobiologie, Westfälische Wilhelms-Universität Münster, Corrensstraße 3, D-48149 Münster, Germany1.
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000473:Alkanes / Q000737:chemistry / Q000378:metabolism*; D019149:Bioreactors; D020118:Cupriavidus necator / Q000737:chemistry* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry; D008970:Molecular Weight; D011091:Polyesters / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D011108:Polymers / Q000737:chemistry / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology / Q000235:genetics; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013455:Sulfur / Q000032:analysis*
D000473:Alkanes; D011091:Polyesters; D011108:Polymers; D013455:Sulfur; D000217:Acyltransferases; C077225:poly(3-hydroxyalkanoic acid) synthase