STRUCTURAL IDENTIFICATION OF POLYHYDROXYALKANOIC ACID (PHA) CONTAINING 4-HYDROXYALKANOIC ACIDS BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY (GC-MS) AND ITS APPLICATION TO BACTERIA SCREENING

The methanolysis products of polyhydroxyalkanoic acids (PHAs) containi ng 4-hydroxybutyric acid (4HB), 4-hydroxyvaleric acid (4HV), and 4-hyd roxyhexanoic acid (4HHx), when analyzed by CC-MS, showed two major chr omatographic peaks with characteristic retention times of each methyl ester of 4-hydroxyalkanoic acid and the corresponding gamma-lactone (g amma-butyrolactone, gamma-valerolactone, gamma-caprolactone, respectiv ely). The method and results of CC-MS could be incorporated into an ef ficient screening procedure for isolation of bacterial strains which c ould accumulate a PHA containing 4-hydroxyalkanoic acid as the princip al monomer from structurally related carbon substrates.