In order to clarify the binding states of copper in microbial cells, copper
biosorption from aqueous systems using the chemically treated Micrococcus
luteus IAM 1056 cells (hot water-treated, diluted NaOH-treated, chloroform-
methanol-treated, and chloroform-methanol/concentrated KOH-treated cells) w
as examined. The intact cells of M. luteus adsorbed 527 mu mol of copper pe
r g cells, and its copper adsorption was very rapid and was affected by the
solution pH. The chloroform-methanol/concentrated KOH-treated cells showed
higher copper biosorption capacity than the intact and the other chemicall
y treated cells. The electron paramagnetic resonance (EPR) parameters, g(pa
rallel to) and \A(parallel to)\, of Cu(II) ion in microbial cells indicate
that Cu(II) ion in the intact and all the chemically treated cells have coo
rdination environments with nitrogen and oxygen as donor atoms, being simil
ar to those of type II proteins. The parameter g(parallel to) also indicate
d that the coupling between Cu(II) ion and the cell materials in the CHCl3-
MeOH/concentrated KOH-treated cells is rather more stable than those betwee
n Cu(II) ion and the cell materials in the other treated cells.