The soil bacterium Arthrobacter chlorophenolicus grows on certain environmental pollutants and degrades them into harmless compounds. It can degrade 4-chlorophenol and some other cyclic compounds. 4-chlorophenol is a common environmental pollutant in the soil, for example on the sites of old wood preservation industries, since it has been used as a wood preservative. It is also formed when waste is incinerated or when paper is bleached with chlorine, and is a constituent of creosote which is used to impregnate e.g. telephone posts.
A. chlorophenolicus can grow in soil conditions that are harsh for bacteria, such as low temperatures or extreme temperature fluctuations. This, in combination with the fact that the bacterium can grow on exceptionally high concentrations of the different phenols, makes it interesting for bioremediation.
In her doctoral work at SLU, Maria Unell studied how A. chlorophenolicus degrades phenols and deals with stress. She has discovered, for example, that it degrades 4-chlorophenol through an effective degradation pathway which had not been seen in aerobic bacteria before. And when cell growth on a mixture of different phenols was studied, it was found that the phenols are degraded in an unexpected order, with the most toxic phenol first and the least toxic one last.
Literature:
Maria Unell, "Physiologial, Genetic and Proteomic Characterisation of Arthrobacter chlorophenolicus during Growth on Different Phenolic Substrates or Temperatures". Thesis from Micro- biology, SLU.