Polyhydroxyalkanoate production by coenzyme a-dependent aldehyde dehydrogenase pathways

摘要

The present invention provides a method of producing polyhydroxyalkanoate (PHA) polymers comprising at least one hydroxyacyl monomer selected from the group consisting of 3-hydroxypropionate, 3-hydroxyvalerate, 4-hydroxybutyrate, 4-hydroxyvalerate, 5-hydroxyvalerate, and 3-hydroxyhexanoate, comprising: expressing in an organism genes encoding a polyhydroxyalkanoate (PHA) synthase and a CoA-dependent aldehyde dehydrogenase, feeding a chemical that is converted by the organism to at least one hydroxyacyl-CoA monomer by an enzyme-catalysed pathway that includes the CoA-dependent aldehyde dehydrogenase activity and allowing polymerisation of the at least one hydroxyacyl-CoA monomer by the PHA synthase to form PHA polymers, and recovering the thus-produced PHA polymers, wherein the organism is produced from a wild-type organism having an endogenous CoA-dependent aldehyde dehydrogenase gene which is modified by gene mutation to increase CoA-dependent aldehyde dehydrogenase activity, or wherein the organism is a recombinant organism in which a gene is recombinantly expressed to encode the CoA-dependent aldehyde dehydrogenase. The present invention also provides a recombinant organism for use in the foregoing method. The present invention also provides a method comprising the step of amplifying a DNA sequence encoding the eutE gene from an E. coli genome using the following oligonucleotides primers: 5' GGT GGT ACC TTA AGA GGA GGT TTT TAT GAA TCA ACA GGA TAT TGA ACA-3' (SEQ ID NO: 1) and 5'-GGT GCG GCC GCT TAA ACA ATG CGA AAC GCA TCG-3' (SEQ ID NO: 2).