Skip to main content
Skip to main menu Skip to spotlight region Skip to secondary region Skip to UGA region Skip to Tertiary region Skip to Quaternary region Skip to unit footer


Nurgul Balci has new publication in Aquatic Geochemistry


Journal of Aquatic Geochemistry: "Microbial Acid Sulfate Weathering of Basaltic Rocks: Implication for Enzymatic Reactions"



Fatih Sekerci1 and Nurgul Balci12

1 Geomicrobiology-Biogeochemistry Laboratory, Department of Geological Engineering, Istanbul Technical University, Istanbul, Turkey

2 Department of Geology, University of Georgia, Athens, USA



Two basaltic rocks were reacted in acid sulfate and non-acid sulfate solutions with an initial pH value of 2 in the presence and absence of A. ferrooxidans to determine if basalt dissolution can support the metabolically active growth of A. ferrooxidans. Similar elemental release rates (RSi, RCa, RMg) calculated for both biotic and abiotic experiments suggest rather a negligible microbial impact on the dissolution of basaltic rocks within the acid sulfate solution. Nevertheless, in contrast with the abiotic experiments, measurements of remarkably high concentration of Fe(III)aq in microbial experiments confirmed the bacterial metabolism. Moreover, detected cell division and increasing total cell numbers with the extent of the experiments provide further evidence for the growth of metabolically active A. ferrooxidans during the dissolution of the rocks. Formation of jarosite ((K, Na, H3O)Fe3(SO4)2(OH)6) only in the biotic experiments is attributed to the microbially catalyzed Fe(II)aq oxidation. Overall, our results showed that acidic solutions that reacted with basaltic rocks can sustain the growth of Fe(II)aq oxidizing bacteria. Furthermore, identification of jarosite only in the biotic experiments emphasizes the enzymatic Fe(II) oxidation as the key step for its formation during basalt weathering at acid conditions, highlighting its biosignature potential on Earth and Earth-like planets (e.g., Mars).



Your gift helps to fund research, travel, and field experience for students and faculty.