The kinetics of the enzymatic formation of 7,8-epoxy-1-octene, 1,2-7,8-diepoxyoctane, and 1,2-epoxyoctane by growing and resting cell suspensions of Pseudomonas oleovorans are described. Formation of 1,2-epoxyoctane occurs concurrently with exponential growth on 1-octene, providing that 1-octene is in excess. Conversion of 1,7-octadiene to 7,8-epoxy-1-octene by cells growing on octane lags behind exponential growth and continues into the stationary phase, terminating upon cell death. Formation of 1,2-7,8-diepoxyoctane does not begin until the cells are well into the stationary phase and also continues until cell death. Results with growing and resting cell suspensions suggest that the various substrates compete for the same enzyme system; that viable cells are essential for substrate transport and epoxidation by whole cells; and that whole cells may concentrate and sequester the epoxides, rendering them unrecoverable by our current methods.