The chromate resistance phenotype of some yeast mutants correlates with a lower level of Cr(V)-species generated in the extra-cellular medium.
The paper describes the selection of chromate-resistant mutants of the yeast Pichia guilliermondii with a higher chromate-reducing activity and reports the EPR-study of Cr(V)-generation in the extra-cellular medium during the reduction of chromate by the yeast culture. It is shown that the reduction of chromate to Cr(III) species runs through the extra-cellular generation of Cr(V)-intermediate(s), thus supporting the assumption about the existence of an extra-cellular pathway of Cr(VI)-reduction. Furthermore, it is demonstrated that the chromate-resistance phenotype of tested mutants correlates with a lower stationary level of Cr(V)-species in the medium. It is thus suggested that isolated mutants can be used as sources of Cr(III)-biocomplexes due to their ability to effectively reduce chromate to Cr(III)-chelates with potential pharmacological applications.
Department of Analytical Biotechnology, Institute of Cell Biology, NAS of Ukraine, Drahomanov Street 14/16, Lviv 79005, Ukraine.
Helena
H
Ksheminska
Taras
T
Honchar
Yuriy
Y
Usatenko
Galina
G
Gayda
Mykhailo
M
Gonchar
D002840:Chromates / Q000737:chemistry / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D009154:Mutation; D010641:Phenotype; D010843:Pichia / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D002840:Chromates; D003470:Culture Media