Catabolism of Wax Esters in Acinetobacter calcoaceticus

1. The rate of wax ester degradation was determined in A. calcoaceticus NCIB 8250 and the following results were obtained: (a) The initial and final rates of wax degradation were 22.5 and 3.3 umol (g dry wt bacteria)-1 h-1 respectively. The initial rate of wax degradation was 85% higher than that of final rate (3-6 h). (b) The rate of endogenous respiration was measured during wax ester degradation. The endogenous consumption of oxygen, 0.13 mmol (g dry wt bacteria)-1 h-1, was reduced by 10% during the fast phase of wax degradation and by 20% after 3 h. (c) The viability of the bacteria having a low or high wax content was determined during carbon and energy starvation condition. 50% of the bacteria with a low content of wax esters were not viable after 84 h but 50% of the bacteria with a high wax content were still viable after 154 h. (d) From literature values for the maintenance energy requirements as oxygen consumption, the initial fast rate of wax esters degradation provides approximately 40% of the energy required for the maintenance of viability, and in the final slower rate would only provide about 7% of the maintenance energy required for the maintenance of viability