FDA hydrolysis and resazurin reduction as a measure of microbial activity in sediments from the south-east Atlantic

Abstract

Esterase and dehydrogenase activities were determined in depth profiles of sediments from the south-east Atlantic using fluorometrtc methods. The sensitivity of both methods was sufficient to record enzymatic activities in deep-sea clay and foraminiferous sand. Depending on water depth and location, significant differences between the depth profiles of enzyme activities could be determined. They appear to be dependent on the organic-matter input from sedimentation. Conclusions about the mode of microbial degradation of organic matter (oxic, anoxic, type of electron acceptors) are possible, using suitable chemical parameters. Under oxic conditions (Eh > 200 my) it was possible (using the method developed for dehydrogenase activities) to determine depth profiles similar to those of the esterase activities. Under suboxic or anoxic conditions, an appropriate separation between biological (dehydrogenase activity) and chemical resazurin reduction was not possible.

Effects of water warming on bank filtration: experimental enclosure studies

“…Dehydrogensases and esterases are important enzyme groups for determining total microbial activities, because of their importance for microbial metabolism and the multitude of reactions they catalyse [28].…”

“…Dehydrogenases as respiratory chain enzymes play a major role in the energy production of organisms and thus fulfil a significant role in the oxidation of organic matter, by analysing this enzyme it is possible to detect metabolically active microorganisms and thus can be used as an indicator of biological redox systems and as a measure of microbial activity in soil [28,29]. Dehydrogenase activity can be measured using TTC (triphenyltetrazolium chloride) as artificial electron acceptors and was performed according to the German Standard DIN ISO 23753-1.…”

Development of a sensitive and rapid method for the measurement of total microbial activity using fluorescein diacetate (FDA) in a range of soils

“…Since 1982, FDA hydrolysis has been used to measure total microbial activity in a range of samples from mould growth on wood and other building materials (Bjurman, 1993), to plant residues (Zablotowicz et al, 1998), to stream sediment biofilms (Battin, 1997), activated sludge (Fontvieille, 1992) and deep sea clay and sand sediment profiles (Gumprecht et al, 1995).…”

The Effects of Cationic Surfactants on Marine Biofilm Growth on Hydrogels

“…Fluorescein diacetate (3',6'-diacetyl-fluorescein) (FDA) hydrolysis has been used to assess microbial activity in marine (Gumprecht et al, 1995;Poremba, 1995) and freshwater sediments (Battin, 1997), activated sludge (Fontvielle et al, 1992) as well as in pure cultures of bacteria (Schnürer & Rosswall, 1982) and algae (Gilbert et al, 1992). This colourless compound is hydrolysed by both free and membrane bound enzymes (Stubberfield & Shaw, 1990) releasing a coloured end product, fluorescein, which can be measured by spectrophotometry.…”