Canadian Journal of Microbiology · 1959 · 170 citations · 0 references
AgriculturePlant SciencesSoil SciencesSoil BiologySoil MicrobiologySoil ScienceRhizosphere MicrobiologyRhizosphere ProcessesSoil Decomposition ProcessesSoil Enzyme ActivitySoil Microbial PhysiologySoil RespirationMicrobial Soil EcologyOxygen Uptake RateRhizosphere RespirationSoil Enzyme AssaysSoil Microbial Processes
The reduction of 2,3,5-triphenyltetrazolium chloride to triphenylformazan has been used to estimate the dehydrogenase activity of the soil microflora in situ. Preliminary investigations suggest that the formation of the formazan may be used as an index of endogenous respiration in soil since a significant correlation has been obtained between dehydrogenase activity and the oxygen uptake of a number of different untreated soils. A direct relationship also was observed between formazan formation and the respiration of a soil sampled at intervals after the application of fresh plant material. In a survey of a number of field soils no relationship was found between dehydrogenase activity and bacterial numbers; however, the two parameters were parallel during the decomposition of flax residues added to one of the soils.