Abstract
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.
Original language | American English |
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Pages (from-to) | 127-133 |
Number of pages | 7 |
Journal | FEMS Microbiology Letters |
Volume | 45 |
Issue number | 3 |
DOIs | |
State | Published - Jun 1987 |
Keywords
- Anaerobic settlement
- Hydrogen evolution
- Microbial activity
- Tetrazolium salt