Mochizuki_2003_Arch.Microbiol_180_490

A bacterium, strain 314B, able to assimilate ( S)-5-oxo-2-tetrahydrofurancarboxylic acid was isolated from soil and identified as Erwinia cypripedii. A lactonase hydrolyzing ( S)-5-oxo-2-tetrahydrofurancarboxylic acid to l-alpha-hydroxyglutaric acid was purified 63-fold with 2% recovery from crude extracts of this bacterium to homogeneity as judged by SDS-PAGE. The molecular masses estimated by SDS-PAGE and gel filtration were 41 kDa and 79 kDa, respectively. The maximum activity was observed at pH 6.5-7.5 and 35-45 degrees C. The enzyme showed lower activity toward dl-2-oxotetrahydrofuran-4,5-dicarboxylic acid, but did not act on ( R)-5-oxo-2-tetrahydrofurancarboxylic acid and other natural and synthetic lactones tested.