The propene isolated strain Xanthobacter Py2 was able to grow on I-pentene. The biomass yield for growth under l-pentene limiting conditions was 0.48 (Ceq/Ceq). Upon storage at both +4 degrees C and -20 degrees C no loss of enzymatic epoxide degrading activity in resting cell suspensions was observed after a month. However, activity decay was pronounced during the stationary phase of growth as well as under reaction conditions.