ISOLATION AND CHARACTERIZATION OF A METHYLOTROPH PRODUCING 3-HYDROXYBUTYRATE-3-HYDROXYVALERATE COPOLYMER

Abstract

A bacterial strain C-02 using methanol as a carbon source was isolated from Gumi Industrial Estate and selected based on its rapid growth and capability of poly-beta-hydroxybutyrate accumulation. Characteristics of strain C-02 showed that it belongs to the Methylococcaceae family, Type II subgroup. Strain C-02 could incorporate valerate into the PHB chain to form 3-hydroxybutyrate and 3-hydroxyvalerate (P(3HB-co-3HV)). Among various nutrient limitation tests, the nitrogen limitation test resulted in the highest content of P(3HB-co-3HV) per dry cell weight, 50%. Under the nitrogen limited condition, the average molecular weight of P(3HB-co-3HV) obtained was determined to be approximately 2.8X10(5) daltons.