Candida pseudoglaebosa and Kodamaea ohmeri are capable of degrading alkanes in the presence of heavy metals

• Published in: Journal of basic microbiology Vol. 59; no. 8; p. 792
• Main Authors: Ortiz-Álvarez, Jossue, Vera-Ponce de León, Arturo, Trejo-Cerro, Oscar, Vu, Hoa T, Chávez-Camarillo, Griselda, Villa-Tanaca, Lourdes, Hernández-Rodríguez, César
• Format: Journal Article
• Language: English
• Published: Germany 11-06-2019
• Subjects: Alkanes - chemistry; Alkanes - metabolism; Biodegradation, Environmental; Biomass; Candida - classification; Candida - genetics; Candida - growth & development; Candida - metabolism; Cytochrome P-450 Enzyme System - genetics; DNA, Ribosomal - genetics; Fungal Proteins - genetics; Hydrogen-Ion Concentration; Kinetics; Metals, Heavy - metabolism; Phylogeny; Saccharomycetales - classification; Saccharomycetales - genetics; Saccharomycetales - growth & development; Saccharomycetales - metabolism; Candida pseudoglaebosa; Kodamaea ohmeri; heavy metal tolerance; hydrocarbonoclastic yeast; CYP52 genes
• ISSN: 0233-111X; 1521-4028
• DOI: 10.1002/jobm.jobm201900027

The aim of this study was to examine four strains of two yeast species in relation to their capability for assimilating alkanes in the presence of heavy metals (HMs). The four strains tested were Candida pseudoglaebosa ENCB-7 and Kodamaea ohmeri ENCB-8R, ENCB-23, and ENCB-VIK. Determination was made of the expression of CYP52 genes involved in alkane hydroxylation. When exposed to Cu
, Zn
, Pb
, Cd
, and As
at pH 3 and 5, all four strains could assimilate several n-alkanes having at least six carbon atoms. The three K. ohmeri strains could also utilize branched alkanes, cycloalkanes, and n-octanol as sole carbon sources. Kinetic assays demonstrated greater biomass production and specific growth of the yeasts exposed to long-chain n-alkanes. Fragments of paralogous CYP52 genes of C. pseudoglaebosa ENCB-7 and K. ohmeri ENCB-23 were amplified, sequenced, and phylogenetically evaluated. Reverse-transcription polymerase chain reaction revealed that n-nonane and n-decane induced to CpCYP52-G3, CpCYP52-G9, and CpCYP52-G10. KoCYP52-G3 was induced with n-decane and n-octanol. Also, CpCYP52-G3 and CpCYP52-G9 were induced by glucose. In conclusion, C. pseudoglaebosa and K. ohmeri were able to degrade several alkanes in the presence of HMs and under acidic conditions. These yeasts harbor paralogous alkane-induced CYP52 genes, which display different profiles of transcriptional expression.