Calcite precipitation by marine bacteria∗

Publisher Website
Google Scholar
Abstract
Calcite precipitation occurs when trimethylamino‐N‐oxide and medium are added to surface waters collected above Lodestone and Keeper Reefs of the Great Barrier Reef. The calcium content of the water was initially 430 ppm. After 30 days incubation at 28 °C, the pH had risen and only 90 ppm of calcium remained in solution. The precipitate was analyzed by X‐ray diffraction and was found to be calcite. During anaerobic incubation of the pure cultures of calcite precipitating bacteria in seawater containing TMAO and medium the pH rose rapidly, the Eh fell quickly, but the precipitation of calcite followed more slowly. Calcite precipitation also occurred aerobically. The binding of 45Ca by bacteria was demonstrated. 14C‐carbonate resulting from bacterial action on 14C‐aspartate was found to be present in the precipitated calcite.