Formation of sphalerite (ZnS) deposits in natural biofilms of sulfate-reducing bacteria.
Abundant, micrometer-scale, spherical aggregates of 2- to 5-nanometer-diameter sphalerite (ZnS) particles formed within natural biofilms dominated by relatively aerotolerant sulfate-reducing bacteria of the family Desulfobacteriaceae. The biofilm zinc concentration is about 10(6) times that of associated groundwater (0.09 to 1.1 parts per million zinc). Sphalerite also concentrates arsenic (0.01 weight %) and selenium (0.004 weight %). The almost monomineralic product results from buffering of sulfide concentrations at low values by sphalerite precipitation. These results show how microbes control metal concentrations in groundwater- and wetland-based remediation systems and suggest biological routes for formation of some low-temperature ZnS deposits.
Labrenz
M
M
Department of Geology and Geophysics, University of Wisconsin-Madison, 1215 West Dayton Street, Madison, WI 53706, USA.
Druschel
G K
GK
Thomsen-Ebert
T
T
Gilbert
B
B
Welch
S A
SA
Kemner
K M
KM
Logan
G A
GA
Summons
R E
RE
De Stasio
G
G
Bond
P L
PL
Lai
B
B
Kelly
S D
SD
Banfield
J F
JF
D001151:Arsenic / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development; D011232:Chemical Precipitation; D003198:Computer Simulation; D003460:Crystallization; D020564:Deltaproteobacteria / Q000254:growth & development / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005296:Ferrous Compounds / Q000378:metabolism; D019015:Geologic Sediments / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000378:metabolism; D008954:Models, Biological; D010084:Oxidation-Reduction; D010100:Oxygen / Q000502:physiology; D012643:Selenium / Q000378:metabolism; D013440:Sulfides / Q000378:metabolism*; D016999:Sulfur-Reducing Bacteria / Q000254:growth & development / Q000378:metabolism*; D013696:Temperature; D014871:Water Microbiology; D017967:Zinc Compounds / Q000378:metabolism*
D005230:Fatty Acids, Nonesterified; D005296:Ferrous Compounds; D008670:Metals; D013440:Sulfides; D017967:Zinc Compounds; D012643:Selenium; C031238:zinc sulfide; D001151:Arsenic; D010100:Oxygen; C022597:ferrous sulfide