title: The oxidative stress response of the filamentous yeastTrichosporon cutaneumR57 to copper, cadmium and chromium exposure.
abstract: Despite the intensive research in the past decade on the microbial bioaccumulation of heavy metals, the significance of redox state for oxidative stress induction is not completely clarified. In the present study, we examined the effect of redox-active (copper and chromium) and redox-inactive (cadmium) metals on the changes in levels of oxidative stress biomarkers and antioxidant enzyme defence inTrichosporon cutaneumR57 cells. This filamentous yeast strain showed significant tolerance and bioaccumulation capability of heavy metals. Our findings indicated that the treatment by both redox-active and redox-inactive heavy metal induced oxidative stress events. Enhanced concentrations of Cu2+, Cr6+and Cd2+caused acceleration in the production of reactive oxygen species (ROS), increase in the level of oxidatively damaged proteins and accumulation of reserve carbohydrates (glycogen and trehalose). Cell response against heavy metal exposure also includes elevation in the activities of antioxidant enzymes, superoxide dismutase and catalase, which are key enzymes for directly scavenging of ROS. Despite the mentioned changes in the stress biomarkers,T. cutaneumdid not show a significant growth diminution. Probably, activated antioxidant defence contributes to the yeast survival under conditions of heavy metal stress.
authors.affiliation: Department of Biotechnology, University of Chemical Technology and Metallurgy , 8 Kliment Ohridsky, 1756 Sofia , Bulgaria.
authors.forename: Nevena
authors.initials: N
authors.lastname: Lazarova
authors.affiliation: Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences , Academician G. Bonchev 26, 1113 Sofia , Bulgaria.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Krumova
authors.affiliation: Department of Immunology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences , Academician G. Bonchev 26, 1113 Sofia , Bulgaria.
authors.forename: Tsvetanka
authors.initials: T
authors.lastname: Stefanova
authors.affiliation: Department of Biotechnology, University of Chemical Technology and Metallurgy , 8 Kliment Ohridsky, 1756 Sofia , Bulgaria.
authors.forename: Nelly
authors.initials: N
authors.lastname: Georgieva
authors.affiliation: Department of Mycology, The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences , Academician G. Bonchev 26, 1113 Sofia , Bulgaria.
authors.forename: Maria
authors.initials: M
authors.lastname: Angelova
keywords: antioxidant defence; biomarkers of oxidative stress; filamentous yeast; heavy metals; oxidative stress