STUDY ON BIODEGRADATION MECHANISM OF TRICLOPYR BUTOXYETHYL ESTER AND UTILIZATION OF A TRICLOPYR BUTOXYETHYL ESTER DEGRADING BACTERIUM, BACILLUS COAGULANS TBE-9

A strain Tbe-9 capable of highly degrading triclopyr butoxyethyl ester (T-BEE) was isolated from farmland soil. Tbe-9 was identified as Bacillus coagulans based on 16S rRNA and analysis of morphology, physiological and biochemical characters. The optimal pH and temperature were 7.0 and 45-50 degrees C respectively. The degradation rate of 100 mg/L T-BEE by strain Tbe-9 could reach 93.8% in 5d. The strain Tbe-9 could tolerate at least 800mg/L T-BEE under the experimental conditions and showed a high tolerance to T-BEE. In addition, the strain Tbe-9 could degrade T-BEE step by step into triclopyr and 3,5,6-trichloro-2-pyridinol(TCP), which had the ability to degrade TBEE, triclopyr and TCP. It was concluded that the biodegradation pathway of T-BEE by strain Tbe-9 was as follows: T-BEE -> triclopyr -> TCP -> ... -> CO2+H2O.