Polyhydroxyalkanoate accumulation in Burkholderia sp.: a molecular approach to elucidate the genes involved in the formation of two homopolymers consisting of short-chain-length 3-hydroxyalkanoic acids

Autor: M. F. de Andrade Rodrigues, Pierre A. Berger, Minhtien Tran, Alexander Steinbüchel, Jawed Asrar, Kenneth J. Gruys, Henry E. Valentin
Rok vydání: 2000
Předmět:
Zdroj: Applied Microbiology and Biotechnology. 53:453-460
ISSN: 1432-0614
0175-7598
DOI: 10.1007/s002530051641
Popis: Burkholderia sp. accumulates polyhydrox-yalkanoates (PHAs) containing 3-hydroxybutyrate and 3-hydroxy-4-pentenoic acid when grown on mineral media under limited phosphate or nitrogen, and using sucrose or gluconate as a carbon and energy source. Solvent fractionation and NMR spectroscopic characterization of these polyesters revealed the simultaneous accumulation of two homopolyesters rather than a co-polyester with random sequence distribution of the monomers [Valentin HE, Berger PA, Gruys KJ, Rodrigues MFA, Steinbuchel A, Tran M, Asrar J (1999) Macromolecules 32: 7389-7395]. To understand the genetic requirements for such unusual polyester accumulation, we probed total genomic DNA from Burkholderia sp. by Southern hybridization experiments using phaC-specific probes. These experiments indicated the presence of more than one PHA synthase gene within the genome of Burkholderia sp. However, when total genomic DNA from Burkholderia sp. was used to complement a PHA-negative mutant of Ralstonia eutropha for PHA accumulation, only one PHA synthase gene was obtained resembling the R. eutropha type of PHA synthases, based on amino acid sequence similarity. In addition to the PHA synthase gene, based on high sequence homology, genes encoding a beta-ketothiolase and acetoacetyl-CoA reductase were identified in a gene cluster with the PHA synthase gene. The arrangement of the three genes is quite similar to the R. eutropha poly-beta-hydroxybutyrate biosynthesis operon.
Databáze: OpenAIRE
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