Method for producing polyhydroxyalkanoate copolymer from saccharide raw material

A method for producing poly(3-hydroxybutyrate-co-3-hydroxyhexanote), comprising:

• transforming a recombinant Cupriavidus necator strain imparted with the ability to produce poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) by homologous recombination of crotonyl-CoA reductase gene, (R)-specific enoyl-CoA hydratase gene and ethylmalonyl-CoA decarboxylase gene in a chromosome of the strain, or transforming by introducing an autonomously replicating vector having these genes incorporated in that strain, and cultivating the transformant in a medium containing a saccharide and/or glycerol as a carbon source,
• wherein the crotonyl-CoA reductase gene is composed of:
• (a) a nucleic acid containing the base sequence set forth in SEQ ID NO:
• 1 or 2, or
• (b) a nucleic acid that hybridizes under stringent conditions with a nucleic acid containing the base sequence set forth in SEQ ID NO:
• 1 or 2 and encodes a protein having catalytic activity that forms butyryl-CoA from crotonyl-CoA,
• wherein the (R)-specific enoyl-CoA hydratase gene is obtained from Cupriavidus necator, and is composed of:
• (a) a nucleic acid containing the base sequence set forth in SEQ ID NO:
• 3, or
• (b) a nucleic acid that hybridizes under stringent conditions with a nucleic acid containing the base sequence set forth in SEQ ID NO:
• 3 and encodes a protein having activity that converts an intermediate in the fatty acid β-oxidation pathway in the form of 2-enoyl-CoA to (R)-3-hydroxyacyl-CoA, and
• wherein the ethylmalonyl-CoA decarboxylase gene is composed of:
• (a) a nucleic acid containing the base sequence set forth in SEQ ID NO:
• 4, or
• (b) a nucleic acid that hybridizes under stringent conditions with a nucleic acid containing the base sequence set forth in SEQ ID NO:
• 4 and encodes a protein having catalytic activity that forms butyryl-CoA by decarboxylation of ethylmalonyl-CoA, wherein the stringent conditions comprise prewashing in a prewashing solution containing 5×SSC, 0.5% SDS and 1.0 mM EDTA (pH 8.0), hybridizing in a hybridization solution containing 2×SSC to 6×SSC and approximately 50% formamide at about 40° C. to 50° C., and washing in 0.5×SSC and 0.1% SDS at about 60° C.