In vivo 31P and 13C NMR investigations of Rhodococcus rhodochrous metabolism and behaviour during biotransformation processes.

AIMS: The strain Rhodococcus rhodochrous OBT18 was isolated from a water treatment plant used to decontaminate industrial effluents containing benzothiazole derivatives. Aims of the work are to study the central metabolism of this strain and more specifically its behaviour during biodegradation of 2-aminobenzothiazole.

METHODS AND

RESULTS

In vivo(13)C and (31)P NMR experiments showed that this strain contains storage compounds such as polyphosphates, glycogen and trehalose and produces biosurfactants containing trehalose as sugar unit. Trehalose can be synthesized after reversion of the glycolytic pathway. In vivo(31)P NMR experiments showed that energy metabolism markers such as the intracellular pH and the ATP concentration did not change during biotransformation processes when R. rhodochrous was exposed to potentially toxic compounds including iron complexes and (* )OH radicals. Also R. rhodochrous recovers the normal values of ATP and pH after anoxia/reoxygenation cycle very quickly.

CONCLUSIONS

Rhodococcus rhodochrous carbon and energy metabolism is well adapted to different stresses and consequently to live in the environment where conditions are constantly changing.

SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study can be used to understand the behaviour of this bacterium in natural environments but also in water treatment plants where iron and UV light are present.