Reproducing authigenic carbonate precipitation in the hypersaline Lake Acıgöl (Turkey) with microbial cultures

Author(s)
Nurgul Balci, Meryem Menekşe, Nevin Gül Karagüler, M. Şeref Sönmez, Patrick Meister
Abstract

In the present study, laboratory precipitation experiments using similar water chemistry and two different bacterial cultures from Lake Acıgöl sediments, a hypersaline lake in Turkey, were performed to reproduce mineral assemblages similar to those found in the lake. Two different bacterial cultures induce various calcium/magnesium carbonates precipitation under all the experimental conditions (solid vs. liquid): Hydromagnesite, dypingite, huntite, monohydrocalcite, and aragonite. The geochemical program PHREEQC was used to calculate the mineral saturation indexes in the cultures and in lake water. Carbonate mineral assemblages identified in the experiments seem to be independent of the type of microorganisms but rather controlled by the chemical composition and physical conditions of the media. The relative amounts of monohydrocalcite, hydromagnesite, and dypingite are controlled by varying sulfate concentration from 0 to 56 mM. This demonstrates a kinetic effect that could similarly affect the mineral assemblage in the lake. Also the spherical morphology of hydromagnesite points to growth of these minerals under partial inhibition in the brine under high concentrations of ions and organic polymers produced by the microbial communities. As reproduced by the culture experiments, the authigenic carbonate mineral assemblage of Lake Acıgöl most likely results from interplay of ionic composition of the brine and microbial effects.

Organisation(s)
Department of Geology
External organisation(s)
Istanbul Technical University, Max-Planck-Institut für marine Mikrobiologie
Journal
Geomicrobiology Journal: an international journal of geomicrobiology and microbial biogeochemistry
Volume
33
Pages
758-773
No. of pages
16
ISSN
0149-0451
DOI
https://doi.org/10.1080/01490451.2015.1099763
Publication date
2016
Peer reviewed
Yes
Austrian Fields of Science 2012
105128 Geomicrobiology
Keywords
ASJC Scopus subject areas
Environmental Science(all), Microbiology, Earth and Planetary Sciences (miscellaneous), Environmental Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/reproducing-authigenic-carbonate-precipitation-in-the-hypersaline-lake-acgoel-turkey-with-microbial-cultures(cbc8eceb-bce5-4fce-bbd3-a356e8f7e735).html