Ordered Low-Temperature Dolomite Mediated by Carboxyl-Group Density of Microbial Cell Walls

Ordered Low-Temperature Dolomite Mediated by Carboxyl-Group Density of Microbial Cell Walls

  • Post by:
  • November 16, 2018
  • Comments off

Abundant in the ancient rock record, early dolomite remains scarce in modern systems at low temperatures (lt 50 deg C), even those systems supersaturated with respect to dolomite. This scarcity is attributed to kinetic inhibition including complexation of Mg 2+ by water and sulfate, carbonate activity, and Mg: Ca ratio. Recent investigations point to a function for microbial metabolisms and surfaces, in which disordered phases are formed. Here, we report the precipitation of primary ordered dolomite at 30 deg C, facilitated solely by the cell walls of two nonmetabolizing archaea from saline solutions with an Mg: Ca ratio of 1: 1, 5: 1, and 10: 1, and slightly saturated with respect to dolomite. Control experiments using bacteria and functionalized microspheres did not precipitate dolomite. Archaeal cell wall functional groups were approximately one order of magnitude higher than the bacteria and spheres used in this study …

Categories: