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Dehydrogenase activity of forest soils depends on the assay used

100%

Januszek K., Blonska E., Dluga J., Socha J.

International Agrophysics

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2015

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tom 29

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nr 1

Dehydrogenases are exclusively intracellular enzymes, which play an important role in the initial stages of oxidation of soil organic matter. One of the most frequently used methods to estimate dehydrogenase activity in soil is based on the use of triphenyltetrazolium chloride as an artificial electron acceptor. The purpose of this study was to compare the activity of dehydrogenases of forest soils with varied physicochemical properties using different triphenyltetrazolium chloride assays. The determination was carried out using the original procedure by Casida et al., a modification of the procedure which involves the use of Ca(OH)2 instead of CaCO3, the Thalmann method, and the assay by Casida et al. without addition of buffer or any salt. Soil dehydrogenase activity depended on the assay used. Dehydrogenase determined by the Casida et al. method without addition of buffer or any salt correlated with the pH values of soils. The autoclaved strongly acidic samples of control soils showed high concentrations of triphenylformazan, probably due to chemical reduction of triphenyltetrazolium chloride. There is, therefore, a need for a sterilization method other than autoclaving, ie a process that results in significant changes in soil properties, thus helping to increase the chemical reduction of triphenyltetrazolium chloride.

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The optimal TTC dose and its chemical reduction level during soil dehydrogenase activity assay

100%

Wolinska A., Zapasek M., Stepniewska Z.

Acta Agrophysica

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2016

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tom 23

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nr 2

2,3,5-triphenyltetrazolium chloride (TTC) is a dye largely used for determination of microbiological activity in soil samples by dehydrogenase assay. TTC is colourless in the oxidised form and red when reduced, due to formation of the product 1,3,5-triphenyl formazan (TPF). In this study, different doses of TTC ranging from 0.2 to 3.0% were added to six different soil types with the aim to verify the effect of chemical TTC reduction and to optimise the substrate dose in order to prevent a toxic effect on microorganisms. Regarding the technical simplicity and cost-effectiveness, the TTC assay is commonly recommended as an efficient method for determination of soil biological activity, provided that an appropriate concentration is applied, depending on the soil type. The lowest TTC levels of 0.2 and 0.5% are recommended for Albic Luvisol and Eutric Fluvisol, respectively, and the highest (2%) for Brunic Arenosol and Haplic Luvisol soils. It has also been demonstrated that DHA has biological origin in more than 90%, whilst chemical TTC reduction accounts for less than 10%, and therefore does not interfere with the correctness of the results obtained.

3

Economic aspects of chemical reduction on farming - future role of precision farming

84%

Takacs-Gyorgy K.

Acta Scientiarum Polonorum. Oeconomia

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2007

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tom 06

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nr 3

115-120

Ograniczanie wyników

1 Acta Agrophysica

1 Acta Scientiarum Polonorum. Oeconomia

1 International Agrophysics

1 Blonska E.

1 Dluga J.

1 Januszek K.

1 Socha J.

1 Stepniewska Z.

1 Takacs-Gyorgy K.

1 Wolinska A.

1 Zapasek M.

1 2016

1 2015

1 2007

Dehydrogenase activity of forest soils depends on the assay used

The optimal TTC dose and its chemical reduction level during soil dehydrogenase activity assay

Economic aspects of chemical reduction on farming - future role of precision farming