R. Blake et N. Ohmura, Thiobacillus ferrooxidans binds specifically to iron atoms at the exposed edge of the pyrite crystal lattice, PROCESS MET, 9, 1999, pp. 663-672
Previous studies from our laboratories suggested that the specific adhesion
of Thiobacillus ferrooxidans to pyrite was mediated by aporusticyanin loca
ted on the outer surface of the bacterial cell. The mechanism of that adhes
ion was investigated in more detail. The adhesion of either intact cell or
purified aporusticyanin to pyrite was severely inhibited when the mineral w
as preincubated with ethylenediaminetetraacetic acid, cyanide, or I,10-phen
anthroline. This inhibition was relieved in the presence of sufficient solu
ble ferrous ions to coordinate the chelator and compete with the pyrite. A
His85Ala mutant aporusticyanin bound much less tightly to pyrite than did t
he wild type apoprotein. Taken together, these observations indicate that b
inding of the aporusticyanin to solid pyrite is accomplished in part by coo
rdination of the unoccupied copper ligands with iron atoms at the exposed e
dge of the pyrite crystal lattice.