Pseudomonas fluorescence KNU417 was able to degrade up to 700 mg/L of phenol in 65 h but could not degrade 1,000 mg/L of phenol. Phenol degradation rate was noticeably enhanced by pre-adaptation. In addition, the cell was able to degrade up to 1,300 mg/L of phenol by pre-adapting to 700 mg/L of phenol. Repeated adaptations to the same concentration of phenol showed negligible increase in degradation rate. Also, relatively low concentration of phenol (100-700 mg/L) required only one pre-adaptation while high concentration (1,000 mg/L) did two consecutive stepwise pre-adaptations for rapid degradation. Optimal adaptation routes were suggested for the fast phenol degradation. For example, 1,000 mg/L of phenol was degraded as fast as in 48 h when the cell was pre-adapted to 100 and 300 mg/L of phenol sequentially. The mechanism of adaptation was explained in terms of catechol 1,2-dioxygenase induction, related to aromatic ring cleavage.

A microorganism capable of degrading phenol was isolated from crude oil contaminated soil and identified as Pseudomonas fluorescence. A porous polymer bead of polyvinyl alcohol (PVA) and Xanthan gum was found to be the best entrapment for phenol degradation in terms of bead shape (spherical form), bead strength, non-agglomeration, phenol degradation rate, and cell holding inside the bead. Activated carbon was co-immobilized with the microorganism in the bead, which readily adsorbed phenol to decrease initial phenol concentration. Due to the decreased phenol concentration, the cells needed shorter adaptation time after which the microorganism stably degraded phenol. When the bead containing microorganism with 1% of activated carbon was packed in a packed-bed bioreactor, the start-up period was shortened by 40 h and the removal efficiency of phenol during the period was increased by 28% than the case with only microorganism.