A racemic glycidyl butyrate resolving strain, preliminarily identified as a Rhizopus sp., had been isolated from soil. Its extracellular lipase was found to enantioselectively hydrolyze the (S)-enantiomer of the chiral ester, with optimal activities at pH 5.3 and 42 degrees C. Higher enantioselectivity of the enzyme was observed at lower temperatures, while the best enantioselectivity was obtained at pH 5.5-6.0, with an E value (enantiomeric ratio) of 57.