Identification and heterologous expression of the polyhydroxyalkanoate biosynthesis genes from Alcaligenes sp. SH-69

Polyhydroxyalkanoate (PHA) biosynthesis genes were cloned and characterized from Alcaligenes sp. SH-69 which can synthesize poly(3-hydroxybutyrate-co- 3-hydroxyvalerate) from a single carbon source. The DNA sequence analysis r evealed two consecutive genes coding for PHA synthase and beta-ketothiolase and the gene coding for acetoacetyl-Coa reductase located about 2-kbp down stream of the two genes. Recombinant Escherichia coli strains with the clon ed PHA biosynthesis genes synthesized poly(3-hydroxybutyrate) in Luria-Bert ani medium containing 2% glucose and poly(3-hydroxybutyrate-co-3-hydroxyval erate) in M9 minimal medium supplemented with 1% glucose, 1 mM valine, and 2 mM threonine, which demonstrates that the PHA biosynthesis genes of Alcal igenes sp. SH-69 are functional in E. coli.