Open AccessOn the use of tetrazolium salts for the measurement of microbial activity in sediments
Author(s) -
Oren Aharon
Publication year - 1987
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1987.tb02348.x
Subject(s) - formazan , bacteria , tetrazolium chloride , anaerobic bacteria , sulfate reducing bacteria , fermentation , anaerobic exercise , anaerobic respiration , microbial metabolism , chemistry , microbiology and biotechnology , respiration , biochemistry , sulfate , cellular respiration , biology , environmental chemistry , botany , organic chemistry , physiology , medicine , genetics , ischemia , cardiology
In an attempt to understand the significance of microbiol activity measurements in anaerobic sediments by the tetrazolium reduction assay I examined the effect of addition of tetrazolium salts on a variety of anaerobic bacteria of different metabolic types. Triphenyletrazolium chloride was found to be reduced by a variety of obligately anaerobic bacteria that lack cytochromes, and evolve hydrogen during fermentation; thus the assay not only measures respiratory electron transport as was often assumed. Hydrogen evolution is inhibited in hydrogen‐producing fermentative bacteria upon addition of tetrazolium salts, thereby depriving, e.g., the surfate‐reducing bacteria of an important electron donor. Moreover, a dissimilatory sulfate‐reducing bacterium tested did not reduce tetrazolium salts at significant rates. It is thus suggested that the tetrazolium reduction assay applied to anaerobic ecosystems gives a measure for activity of hydrogen‐evolving fermentative bacteria, rather than for overall bacterial metabolism or of anaerobic respiration.