Kinetic parameters of continuous cultures of Bacillusthermoleovorans sp. A2 degrading phenol at 65 °C

Abstract

In this paper, we report on the kinetics of phenol degradation and cell growth in continuous cultures of suspended cells of Bacillus thermoleovorans sp. A2 at 65 °C. A high yield coefficient of Y x/s=0.84 g cell dry weight g −1 phenol was measured at a dilution rate of 0.5 h −1. At the same dilution rate the coefficient for maintenance metabolism (m s) was determined to be 0.045 g phenol g −1 cell dry weight h −1. The maximal growth rate (wash-out) determined at a phenol inlet concentration of 188 mg l −1 was 0.9 h −1. Up to 7 g phenol l −1 per day were degraded in a continuously operated 2-l stirred tank reactor with suspended cells (feed concentration 660 mg l −1). Additionally, yield coefficients for oxygen and ammonium are reported.