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Thermostable peroxidase from Bacillus stearothermophilus.
S Loprasert1, S Negoro, H Okada
1Department of Fermentation Technology, Osaka University, Japan.
Journal of General Microbiology
|July 1, 1988
Summary
A heat-stable peroxidase from Bacillus stearothermophilus was purified, revealing it contains protohaem IX. This enzyme exhibits optimal activity at pH 6 and 70°C, functioning as both a peroxidase and catalase.
Area of Science:
- Biochemistry
- Enzymology
- Microbial biochemistry
Background:
- Peroxidases are crucial enzymes involved in various biological processes.
- Bacillus stearothermophilus is a thermophilic bacterium known for its heat-stable enzymes.
Purpose of the Study:
- To purify and characterize a peroxidase enzyme from Bacillus stearothermophilus.
- To determine the enzyme's structural, spectral, and kinetic properties.
Main Methods:
- Homogeneous purification of the peroxidase.
- Spectroscopic analysis (Soret band, reduced pyridine haemochrome).
- Enzyme activity assays (peroxidase and catalase) at varying pH and temperature.
Main Results:
- The purified enzyme has a molecular weight of 175,000 Da, composed of two equal subunits.
- Spectroscopic data confirmed protohaem IX as the prosthetic group.
- Optimal activity at pH 6 and 70°C, with stability up to 70°C.
- Michaelis constants (Km) for H2O2 were 1.3 mM (peroxidase) and 7.5 mM (catalase).
Conclusions:
- The Bacillus stearothermophilus peroxidase is a thermostable enzyme containing protohaem IX.
- Its dual activity as a peroxidase and catalase makes it a promising candidate for industrial applications.