title: Cr(VI) reduction in a chromate-resistant strain of Candida maltosa isolated from the leather industry.
abstract: A Cr(VI)-resistant yeast was isolated from tanning liquors from a leather factory in Leon, Guanajuato, Mexico. Based on morphological and physiological analyses and the D1/D2 domain sequence of the 26S rDNA, the yeast was identified as Candida maltosa. Resistance of the strain to high Cr(VI) concentrations and its ability to chemically reduce chromium was studied. When compared to the three laboratory yeasts Candida albicans, Saccharomyces cerevisiae and Yarrowia lipolytica, the C. maltosa strain was found to tolerate chromate concentrations as high as 100 micro g/ml. In addition to this phenotypic trait, the C. maltosa strain showed ability to reduce Cr(VI). Chromate reduction occurred both in intact cells (grown in culture medium or in soil containing chromate) as well as in cell-free extracts. NADH-dependent chromate reductase activity was found associated with soluble protein and, to a lesser extent, with the membrane fraction.
authors.affiliation: Instituto de Investigación en Biología Experimental, Facultad de Química, Guanajuato 36000, Guanajuato, Mexico.
authors.forename: Rocío
authors.initials: R
authors.lastname: Ramírez-Ramírez
authors.forename: Carlos
authors.initials: C
authors.lastname: Calvo-Méndez
authors.forename: Mario
authors.initials: M
authors.lastname: Avila-Rodríguez
authors.forename: Patricia
authors.initials: P
authors.lastname: Lappe
authors.forename: Miguel
authors.initials: M
authors.lastname: Ulloa
authors.forename: Ricardo
authors.initials: R
authors.lastname: Vázquez-Juárez
authors.forename: J Félix
authors.initials: JF
authors.lastname: Gutiérrez-Corona
mesh_terms: D002175:Candida / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D002840:Chromates / Q000494:pharmacology*; D002857:Chromium / Q000493:pharmacokinetics*; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D024881:Drug Resistance, Bacterial; D010084:Oxidation-Reduction; D012331:RNA, Fungal / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D013633:Tanning
chemical_list: D002840:Chromates; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D012331:RNA, Fungal; D012335:RNA, Ribosomal; C065096:RNA, ribosomal, 26S; D002857:Chromium; C074702:chromium hexavalent ion