Impact of enzyme stabilizers on the characteristics of biomodules for bioluminescent biosensors

Abstract

The biomodule of bioluminescent biosensor based on a coupled enzyme system NADH:FMN-oxidoreductase and luciferase, co-immobilized with substrates in dried starch or gelatin gels, has been developed. We studied the impact of several stabilizers-dithiothreitol (DTT), bovine serum albumin (BSA) and mercaptoethanol (ME) on the biomodule's activity, storage stability and sensitivity to toxic substances. The inclusion of stabilizers increases the activity of the biological module by more than 150%. To achieve the combination of high activity, prolonged storage time and acute sensitivity to toxic substances within maximum permissible concentration we used starch gel as a carrier adding 100 mu M DTT to the immobilized preparation. The gelatin-based biological module had greater storage stability than the starch-based one but demonstrated less sensitivity to toxic substances. (C) 2015 Elsevier B.V. All rights reserved.