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Full-Text Articles in Speleology

Comparing Capabilities Of Shewanella Oneidensis Mr-1 And The Microbial Community Of Iron Caves To Reduce Fe(Iii), Aaron Douglas Pham Jan 2021

Comparing Capabilities Of Shewanella Oneidensis Mr-1 And The Microbial Community Of Iron Caves To Reduce Fe(Iii), Aaron Douglas Pham

Williams Honors College, Honors Research Projects

Caves are generally formed by the erosion and/or dissolution of rock and its subsequent removal by water. Iron ore caves (IOCs) form despite being hosted by relatively insoluble and weathering-resistant rock. Due to the discovery of a microbial community behind the walls of these caves, it was hypothesized that these bacteria could be responsible for speleogenesis. Iron ore exists in an oxidized (Fe(III)) state, but reduced (Fe(II)) form is soluble. It was further reasoned that the bacteria might be able to reduce Fe(III) through direct metabolic activity, which uses iron as an electron acceptor. Here we show that cave microorganisms …


Comparison Of Fe(Iii) Reduction Rates By Iron-Reducing Bacteria Within Sub Muros Samples From Quadrilátero Ferrífero Iron-Ore Caves, Brazil, Summer Ellis Jan 2020

Comparison Of Fe(Iii) Reduction Rates By Iron-Reducing Bacteria Within Sub Muros Samples From Quadrilátero Ferrífero Iron-Ore Caves, Brazil, Summer Ellis

Williams Honors College, Honors Research Projects

Previous research investigating the speleogenesis of iron-ore caves (IOC) in the Quadrilátero Ferrífero, or “Iron Quadrangle,” of Brazil suggests that microbial iron reduction and subsequent dissolution of the surrounding Fe(III) rich rocks is responsible for cave formation. A soft intra-wall substance (sub muros) containing iron-reducing bacteria (FeRB) was discovered underneath the durable crusts of cave walls. The goal of the study was to determine if reduction rates were comparable between sub muros samples, while additionally observing how different electron donors affect microbial iron reduction. To do this, I compared Fe(III) reduction rates between sub muros samples collected from …