P. Devasia et al., SURFACE-CHEMISTRY OF THIOBACILLUS-FERROOXIDANS RELEVANT TO ADHESION ON MINERAL SURFACES, Applied and environmental microbiology, 59(12), 1993, pp. 4051-4055
Thiobacillus ferrooxidans cells grown on sulfur, pyrite, and chalcopyr
ite exhibit greater hydrophobicity than ferrous ion-grown cells. The i
soelectric points of sulfur-, pyrite-, and chalcopyrite-grown cells we
re observed to be at a pH higher than that for ferrous ion-grown cells
. Microbe-mineral interactions result in change in the surface chemist
ry of the organism as well as that of the minerals with which it has i
nteracted. Sulfur, pyrite, and chalcopyrite after interaction with T.
ferrooxidans exhibited a significant shift in their isoelectric points
from the initial values exhibited by uninteracted minerals. With anti
bodies raised against sulfur-grown T. ferrooxidans, pyrite- and chalco
pyrite-grown cells showed immunoreactivity, whereas ferrous ion-grown
cells failed to do so. Fourier transform infrared spectroscopy of sulf
ur-grown cells suggested that a proteinaceous new cell surface appenda
ge synthesized in mineral-grown cells brings about adhesion to the sol
id mineral substrates. Such an appendage was found to be absent in fer
rous ion-grown cells as it is not required during growth in liquid sub
strates.