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Updated: Aug 8, 2026
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Determination of Microbial Extracellular Enzyme Activity in Waters, Soils, and Sediments using High Throughput Microplate Assays
Published on: October 1, 2013
40.2K
Simple kinetics, assay, and trends for soil microbial catalases
Michael Chabot1, Ernesto Morales1, Jacob Cummings1
1Cal Poly Pomona, Chemistry & Biochemistry Department, 3801 W. Temple Ave., Pomona, CA, 91768, USA.
Analytical Biochemistry
|August 26, 2020
Summary
Soil microbial communities facing oxidative stress have higher catalase levels. This study developed a kinetic model and assay to measure catalase activity and biomass in diverse soil environments.
Area of Science:
- Environmental microbiology
- Biogeochemistry
- Enzyme kinetics
Background:
- Soil catalases are crucial enzymes involved in oxidative stress response.
- Understanding catalase enzymology and ecology is vital for soil health assessment.
- Previous methods for catalase quantification were limited in field applicability.
Purpose of the Study:
- To develop and apply a simple kinetic model and field-amenable assay for soil catalases.
- To relate kinetic parameters to catalase reaction mechanisms and community structure.
- To estimate catalase biomass and specific activities in various soil ecosystems.
Main Methods:
- Development of a volume displacement assay for catalase activity measurement.
- Application of a kinetic model to determine Michaelis-Menten terms and rate constants (k3').
- Quantification of catalase moles per 16S rRNA gene copy number and specific activities (SAs).
- Incorporation of barometric adjustments for standardized field measurements.
Main Results:
- Biological soil crusts showed lower k3' but significantly higher catalase moles per biomass and SAs compared to garden soils.
- Permafrost and high-elevation soils exhibited the highest SAs.
- Catalase specific activities (SAs) were used to estimate microbial biomass (LOD ~10^4 copy number gdw^-1).
Conclusions:
- Microbial communities experiencing higher oxidative stress exhibit elevated intracellular catalase concentrations and SAs per biomass.
- The developed kinetic approach provides a robust method for assessing soil catalase enzymology and ecology.
- Findings link microbial community structure and function to environmental oxidative stress levels.
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