Degradation of phenol and its methylated homologues by Ochromonas danica

Phenols are one of the most common groups of organic environmental pollutants. In this study, the catabolic versatility of the eukaryotic alga 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 presence of phenol in the incubation medium. Once the phenol had been exhausted (2-3 h) from a phenolic mixture in the incubation media, there was a significant reduction in the rates of xylenol isomer removal and none of these xylenols (250 micromolar) was completely utilised in 6 h. 3,4-Xylenol, however, was completely removed from the growth medium in 3 h, even though all the phenol had disappeared in 2 h.