Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from cottonseedoil and valeric acid in batch culture of Ralstonia sp strain JC-64

A. Ralstonia sp. strain JC-64 that is capable of accumulating poly(3-hydrox ybutyrate-co-3-hydroxyvalerate) (P[3HB-co-3HV]) from cottonseed oil and val eric acid was isolated. By using a high limiting-nitrogen (HLN) mineral med ium as the medium for the second stage of the fermentation process and by a dding the two carbon sources at different times, a range of copolymers with 12-62 mol% of 3HV were produced from a series of HLN mineral mediums conta ining different compositions of cottonseed oil and valeric acid by Ralstoni a sp. JC-64. The melting temperature (T-m) of polyhydroxybutyrate from cott onseed oil was 174 degreesC and that of P(3HB-co-3HV) with the highest 3HV- mol fraction (62%) was 81 degreesC.