Benzothiazole degradation by Rhodococcus pyridinovorans strain PA: evidence of a catechol 1,2-dioxygenase activity.
The pathway for biodegradation of benzothiazole (BT) and 2-hydroxybenzothiazole (OBT) by Rhodococcus pyridinovorans strain PA was studied in detail. The kinetics of biodegradation were monitored by in situ (1)H nuclear magnetic resonance (NMR) in parallel with reversed-phase high-performance liquid chromatography (HPLC). Successive oxidations from BT to OBT and then from OBT to dihydroxybenzothiazole were observed. Further insight was obtained by using a mutant strain with impaired ability to grow on BT and OBT. The precise structure of another intermediate was determined by in situ two-dimensional (1)H-(13)C NMR and HPLC-electrospray ionization mass spectrometry; this intermediate was found to be a ring-opening product (a diacid structure). Detection of this metabolite, together with the results obtained by (1)H and (19)F NMR when cells were incubated with 3-fluorocatechol, demonstrated that a catechol 1,2-dioxygenase is involved in a pathway for biodegradation of BTs in this Rhodococcus strain. Our results show that catechol 1,2-dioxygenase and catechol 2,3-dioxygenase activities may both be involved in the biodegradation of BTs depending on the culture conditions.
Haroune
Nicolas
N
Laboratoire de Synthèse et Etude de Systèmes à Intérêt Biologique, UMR 6504 CNRS-Université Blaise Pascal, 63177 Aubière Cedex, France.
Combourieu
Bruno
B
Besse
Pascale
P
Sancelme
Martine
M
Reemtsma
Thorsten
T
Kloepfer
Achim
A
Diab
Amer
A
Knapp
Jeremy S
JS
Baumberg
Simon
S
Delort
Anne-Marie
AM
D052160:Benzothiazoles; D001673:Biodegradation, Environmental; D050548:Catechol 1,2-Dioxygenase; D002851:Chromatography, High Pressure Liquid; D049308:Dioxygenases; D009682:Magnetic Resonance Spectroscopy; D010105:Oxygenases / Q000378:metabolism*; D012240:Rhodococcus / Q000378:metabolism*; D013844:Thiazoles / Q000378:metabolism*
D052160:Benzothiazoles; D013844:Thiazoles; D010105:Oxygenases; D049308:Dioxygenases; D050548:Catechol 1,2-Dioxygenase; C005465:benzothiazole