Accumulation of Cu and its oxidation state in (rusty-rock lichen) mycobiont

Fujii, Hiromitsu*; Hara, Kojiro*; Komine, Masashi*; Ozaki, Takuo; Onuki, Toshihiko; Yamamoto, Yoshikazu*

We studied the association of a Cu tolerant mycobiont, Tremolecia atrata (rusty-rock lichen) with Cu. T. atrata mycobiont cell aggregates, which grew into a sperical shape, rapidly absorbed Cu into their inner and outer parts. The EDS/SEM study showed that Cu was more highly accumulated in the inner part than the outer part of the aggregates. The XANES study revealed that the Cu absorbed by the T. atrata mycobiont was both monovalent and divalent. These results suggested that the T. atrata mycobiont's high tolerance to Cu is attributable to its ability to store Cu(I) inside the cytoplasm and to adsorb Cu(II) on the cell wall.