Phenols are one of the most common groups of organic environmental pol
lutants. In this study, the catabolic versatility of the eukaryotic al
ga Ochromonas danica (CCAP 933/2B) to degrade mixtures of, rather than
individual, phenols was examined. O. danica, after growth on phenol,
was able to metabolise 2,5-, 2,6- and 3,5-xylenols only in the presenc
e of phenol in the incubation medium. Once the phenol had been exhaust
ed (2-3 h) from a phenolic mixture in the incubation media, there was
a significant reduction in the rates of xylenol isomer removal and non
e of these xylenols (250 mu M) was completely utilised in 6 h. 3,4-Xyl
enol, however, was completely removed from the growth medium in 3 h, e
ven though all the phenol had disappeared in 2 h.