Abstract: The present invention pertains to an enzymatic reaction involving a pyridine nucleotide cofactor, wherein an enzyme is used that has a sequence of greater than 70% identity to SEQ ID NO: 2 and is capable of transferring reducing equivalents between pyridine nucleotide cofactors. Alternatively, a cell transformed to express the enzyme may be used.

Abstract: An enzymically active cell free extract or membrane fraction capable of catalysing the removal of nitrite from hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is provided. The cell free extract is produced by culturing a strain of Rhodococcus rhodochrous bacterium from nature. The strain designated 11Y has been deposited as NCIMB 40820. Methods of bioremediation using the enzymically active cell free extract so produced are also provided. Additionally there is provided a method for detecting the presence of RDX in a sample together with a biosensor for use in such a method. The nitrite produced in the enzyme catalysed reaction with RDX is detected, for example, colorimetrically, or alternatively a product of RDX degradation, such as formal behyde, is detected.

Abstract: An enzyme capable of catalyzing the removal of nitrite from pentaerythritol tetranitrate (PETN) is provided. The enzyme (known as PETN reductase enzyme) is produced by culturing a novel strain of the Enterobacter cloacae bacterium isolated from nature. The strain designated PB2 has been deposited as NCIMB 40718. The amino acid sequence of the enzyme and the genetic sequence which encodes for this enzyme have also been determined. A PETN reductase enzyme encoded by the on gene is provided. A method for producing PETN reductase enzyme in large quantities and methods of bioremediation using the enzyme so produced are also provided. Additionally there is provided a method of detecting the presence of PETN in a sample together with a biosensor for use in such a method.