Kinetic studies of phenol degradation by Rhodococcus sp. P1 I. Batch cultivation

Abstract

Rhodococcus sp. P1 utilizes phenol as the sole carbon and energy source via the β-ketoadipate pathway. In batch cultivation, concentrations up to 2.8g · l^-1 phenol were degraded. The highest values for the specific growth rate of 0.32 h^-1 were obtained at concentrations near 0.25 g · l^-1. At higher concentrations, substrate inhibition was observed, characterized by increases in lag phase and decreasing growth rates. A mathematical expression was proposed to fit the kinetic pattern of phenol inhibition on the specific growth rate μ:

$$\begin{gathered} \mu = \mu _{\max } \frac{S}{{S + K_S }}{\text{ }}\exp {\text{ }}( - (\frac{S}{{K_1 }})^K ) \hfill \\ with{\text{ }}\mu _{\max } = 0.33h^{ - 1} ,{\text{ }}K_S = 0.00032g \cdot 1^{ - 1} ,{\text{ K = 1}}{\text{.44}}{\text{.}} \hfill \\ \end{gathered} $$