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A simple assay for screening microorganisms for chalkophore production
Sukhwan Yoon1, Alan A Dispirito, Stephan M Kraemer
1Department of Civil and Environmental Engineering, The University of Michigan, Ann Arbor, Michigan, USA.
Methods in Enzymology
|March 23, 2011
Summary
Researchers developed a rapid copper assay (Cu-CAS) to detect chalkophores, copper-binding molecules produced by methanotrophs. This method aids in screening for chalkophore production and understanding its genetics.
Area of Science:
- Microbiology
- Biochemistry
Background:
- Methanotrophs, microorganisms that consume methane, produce chalkophores, which are ligands with high affinity for copper.
- A rapid screening method for chalkophore production is needed to study these important microbial compounds.
Purpose of the Study:
- To adapt the chrome azurol S (CAS) assay for detecting chalkophore production in methanotrophs.
- To provide a straightforward method for screening chalkophore expression.
Main Methods:
- The chrome azurol S (CAS) assay was modified by replacing iron(III) chloride with copper(II) chloride, creating the Cu-CAS assay.
- Both liquid and agar plate formats of the Cu-CAS assay were employed.
- The assay was used to screen methanotrophs for chalkophore production.
Main Results:
- The Cu-CAS assay successfully detected chalkophore production in methanotrophs.
- The assay can be used with isolated methanobactin or to screen whole organisms.
- The assay's potential for modification to screen other organisms was noted.
Conclusions:
- The Cu-CAS assay is an effective and inexpensive tool for detecting chalkophores.
- This method facilitates the study of chalkophore synthesis genetics in methanotrophs and potentially other organisms.
- Cross-validation with the original iron-CAS assay is recommended to rule out non-specific copper binding by siderophores.
