GSA Connects 2021 in Portland, Oregon

Paper No. 138-4
Presentation Time: 8:50 AM


MEDINA FERRER, Fernando1, ROSEN, Michael R.2, FEYHL-BUSKA, Jayme3, RUSSELL, Virginia4, SØNDERHOLM, Fredrik5, LOYD, Sean6, SHAPIRO, Russell7, STAMPS, Blake W.8, PETRYSHYN, Victoria A.9, DEMIREL-FLOYD, Cansu10, BAILEY, Jake V.11, JOHNSON, Hope A.12, SPEAR, John R.13 and CORSETTI, Frank3, (1)Earth & Environmental Sciences, University of Minnesota, Twin Cities, Minneapolis, MN 55454, (2)California Water Science Center, US Geological Survey, 2730 North Deer Run Road, Carson City, NV 89701, (3)Department of Earth Sciences, University of Southern California, Los Angeles, CA 90089, (4)Plant and Microbiology, University of California, Berkeley, Berkeley, CA 94720, (5)Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark, (6)Department of Geological Sciences, California State University, Fullerton, Fullerton, CA 92831, (7)Geological and Environmental Sciences, California State University at Chico, Department of Geological and Environmental Sciences, 400 West 1st. Street, Chico, CA 95929-0205, (8)UES, Inc., Dayton, OH 45432, (9)Environmental Studies Program, University of Southern California, Los Angeles, CA 90089, (10)School of Geosciences, University of Oklahoma, 100 East Boyd St., NORMAN, OK 73069, (11)Earth Sciences, University of Minnesota - Twin Cities, 310 Pillsbury Drive SE, Minneapolis, MN 55455, (12)Department of Biological Science, California State University Fullerton, 800 N. State College Blvd, Fullerton, CA 92831, (13)Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401-1887

Carbonate tufa mounds from the alkaline Big Soda Lake (BSL), Nevada, show signs of active and rapid growth associated with groundwater seeping into the lake. Although diverse biofilms are found on the surface of the tufas, the potential effect of microbial activity on carbonate precipitation and tufa growth is unknown. Here we show that BSL tufas host a diverse microbial community that promote carbonate precipitation and potentially contribute to the formation of tufa mounds. Genes associated with metabolic pathways that potentially increase carbonate saturation were found by metagenomic DNA sequencing of biofilm tufas, and in situ enzymatic activity assays showed that both urease and carbonic anhydrase are active in BSL. Microcosm incubation experiments of tufa biofilms showed calcium carbonate precipitation associated with the activity of microbial urease, which provides a potential mechanism of tufa formation. Therefore, active microbial urease possibly catalyzes the rapid growth of columnar tufas in BSL.