UPTAKE OF PHENOL BY THE PHENOL-METABOLIZING BACTERIA OF A STABLE, STRICTLY ANAEROBIC CONSORTIUM

Phenol was absorbed unspecifically by active and by inactivated cells of a strictly anaerobic, phenol-degrading consortium to reach about twice the concentration of the medium. The absorption was temperature-dependent. A Q10 of 1.7 was determined, indicating that accumulation was due to diffusion or facilitated diffusion and not to an active transport process. At increasing phenol concentration in the medium, concentrated cell suspensions adsorpted phenol proportionally until saturation was reached at about 25 nmol phenol/mg cell dry weight. At a phenol concentration in the medium of 2 mm, the washed cell pellet contained 3.5 mm phenol. Under conditions that allowed phenol metabolism (presence of CO2), [C-14]4-hydroxybenzoyl-coenzyme A and [C-14]4-hydroxybenzoate were found as early intermediates of [ U-C-14] phenol degradation for the first time. [C-14]Benzoate was excreted stoichiometrically if phenol degradation to acetate was prevented by H-2. Absolutely no C-14-label was found in the phenylphosphate peak after HPLC separation, which excluded phosphorylation of phenol during uptake or during degradation in the cells.