PROIMI   05436
PLANTA PILOTO DE PROCESOS INDUSTRIALES MICROBIOLOGICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Biomineralization in Candida fukuyamaensis RCL-3 under copper overload
Autor/es:
VERÓNICA IRAZUSTA; LUCAS MICHEL; LUCÍA INÉS FIGUEROA DE CASTELLANOS
Reunión:
Congreso; IX SAMIGE Congreso Argentino de Microbiología general; 2013
Resumen:
Copper (Cu) plays an essential role in cellular metabolism due to its versatility as a biological catalyst.It is required as a catalytic cofactor in many enzymes involved in diverse cellular processes. Whiletrace amounts of copper are essential for life, copper can easily react with oxygen or hydrogenperoxide (H2O2) generating reactive oxygen species (ROS) that may damage cell constituentsthrough the oxidation of proteins, cleavage of DNA and RNA, and lipid peroxidation. Candidafukuyamaensis RCL-3 (NCBI number AY743221), yeast strain isolated from a copper filter plant at theprovince of Tucumán, Argentina, has the ability of supporting high amounts of copper metal by aslowdown in its growth rate. Bioremediation mechanisms as bioaccumulation, biospeciation,biomineralization has been descripting in yeast. In order to understand the mechanism involved in C.fukuyamaensis RCL-3 resistance to copper it was conducted an approach. Atomic absorptionspectroscopy results showed decrease copper concentration (from 0.5 to 0.14 ± 0.05 mM) in theculture medium after 16 h inoculation. At the same time, change in cells coloration to brownish colorwas observed. Is known that cooper sulfide (CuS) mineralization on the surface of cells causes thecells turns brown. Upon addition of KCN to Cu-grown C. fukuyamaensis RCL-3 cells, the brownishcoloration was bleached instantly, and cooper ions were solubilized. Sulfate reduction as the browncoloration of Cu-treated cells was attenuated when ammonium chloride was substituted for ammoniumsulfate in the growth media.The results obtained in the present work show that when exposing C. fukuyamaensis RCL-3 to 0.5mMcopper concentration, is produced a biomineralization process probably involved as cellbioremediation mechanisms.IX