Microbiology Experiment 1 Lab Report (Final) Luo Jinjing Lian Juan and Ng Wenfa.pdf (628.43 kB)
Experiment series in environmental engineering: Experiment 7 (NUS ChBE, AY 2004/2005, Semester 1)
Dehydrogenase enzyme assay (DHA) has been widely used in the
bioremediation field to assess the condition of the soil before the soil
decontamination work is started. DHA is a general measure of the microbial
activity of the soil of all microorganisms.
Thus the value obtained can be used as a general indicator of the general soil
quality. This initial assessment is important in determining the amount
of nutrients that need to be added to the soil in order to allow
microbiological degradation of the contaminant compounds to proceed smoothly.
DHA is actually a measure of the electron transport chain (ETC) activity. It
makes use of the competitive NAD+ inhibitor,
2,3,5-triphenyltetrazolium chloride (TTC) to measure the ETC activity. The DHA
method accomplishes this by conversion of the pale yellow, slightly soluble TTC
to a deep red insoluble precipitate, triphenylformazan (TPF). The concentration
of TPF can then be assessed by the use of the UV-Visible Spectrophotometry. The
objectives of this experiment is to determine the effect of nitrogen,
phosphorus and glucose addition to the soil microbiological activity using the
DHA. From the results of the experiment, 0.5% glucose is determined to have the
greatest positive impact on the soil microbial activity. The other conclusions
that can be drawn from this experiment are on weaker grounds as they do not
agree with theoretical predictions. In this experiment, 2.5% glucose + 4%
ammonium nitrate together with 2.5% glucose + 4% potassium hydrogen phosphate
would produce a microbial activity that is lower than that of 0.5% glucose.
This result may be due to 0.5% glucose. This result may be due to experimental
errors. Further studies should be conducted to investigate the effect of
nitrogen and phosphorus addition to the soil microbial activity of this soil. Done by: Luo Jinjing, Lian Juan and Ng Wenfa
Funding
No funding was used in this student laboratory exercise.
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Categories
- Soil sciences not elsewhere classified
- Soil chemistry and soil carbon sequestration (excl. carbon sequestration science)
- Other environmental sciences not elsewhere classified
- Microbiology not elsewhere classified
- Analytical biochemistry
- Toxicology (incl. clinical toxicology)
- Biocatalysis and enzyme technology
Keywords
Dehydrogenase enzyme assayUV-Visible Spectrophotometry2,3,5-triphenyltetrazolium chloride (TTC)triphenylformazan (TPF)glucosenitrogen and phosphorusSoil ScienceSoil Chemistry (excl. Carbon Sequestration Science)Environmental Sciences not elsewhere classifiedMicrobiologyAnalytical BiochemistryToxicologyBiocatalysis and Enzyme Technology
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