Real-time monitoring of nitrile biotransformations by mid-infrared spectroscopy

In this study mid-infrared spectroscopy was used to follow the kinetics inv olved in nitrile biocatalysis using whole cell suspensions of the bacterium Rhodococcus rhodochrous LL100-21. The bacteria were grown on acetonitrile to induce a two-step enzymatic pathway. Acetonitrile was biotransformed to acetamide by a nitrile hydratase enzyme and subsequently to acetic acid (ca rboxylate ion) by an amidase enzyme. The bacteria were also grown on benzon itrile to induce a one-step enzymatic pathway. Benzonitrile was biotransfor med directly to benzoic acid (carboxylate ion) by a nitrilase enzyme. These reactions were followed by React IR using a silicon probe and gave excelle nt quantitative and qualitative real-time data of both nitrile biocatalytic reactions. This study has shown that this novel technique has potentially useful applications in biocatalysis. (C) 2000 Elsevier Science B.V. All rig hts reserved.