Fluorescein diacetate hydrolysis as a measure of microbial activity in aquatic systems: Application to activated sludges

Abstract

International audienceFluorescein diacetate (FDA) hydrolysis has mainly been used, in soil studies, for measurement of microbial activity and/or for enumeration of bacteria. A protocol is proposed to apply the method to sewage treatment plant activated sludge. The results are compared with values of ETS (electron transport system) activity and oxygen consumption. Unlike ETS activity, FDA hydrolysis is not expected to be proportional to O2 consumption. However, its application to aquatic systems is simpler, less expensive and give results with better reproducibility. FDA hydrolysis may thus allow study of biological activity in situations where extensive surveys in time and/or space are needed