A genetically engineered strain of Pseudomonas is provided, which is capable of metabolizing lactose as a sole carbon source in the production of polyhydroxyalkanoates (PHAs). A method of engineering microorganisms and a method of PHA production are also provided, wherein lactose is used as a sole carbon source.

The present invention relates to a recombinant microorganism metabolizing 3,6-anhydro-L-galactose and a use thereof, and, more particularly, can produce ethanol from a recombinant microorganism expressing an enzyme group involved in a metabolic pathway of 3,6-AHG.