Biodegradation of 3,5,6-trichloro-2-pyridinol by Cupriavidus sp. DT-1 in liquid and soil enviroments

The bactrial strain Cupriavidus sp. DT-1 can degrade 3,5,6-trichloro-2-pyridinol (TCP) and transform it into 2-hydroxypyridine (2-HP). This is a unique degradation pathway of TCP but incomplete. In the present study, strain DT-1 could degrade 2-HP at a high concentration 500 mg/L and use it as sole carbon source for growth. Three metabolites (nicotine blue, maleamic acid and fumaric acid) were detected in the medium and the complete degradation pathway of TCP was derived. Inoculation of TCP-contaminated soils with strain DT-1 resulted in a degradation rate 94.4% and 86.7% as compared to 20.4% and 28.4% in uninoculated soils, respectively. Fluorescent marker gene gfp was introduced into strain DT-1 and a new strain DT-1- gfp was created, viability test showed the strain could survive well in soils for more than 35 d. This finding suggests that strain DT-1 has potential for use in bioremediation of TCP-contaminated environments.