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Microarray analysis of a microbe-mineral interaction

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Original languageEnglish
Pages (from-to)446-456
Number of pages11
JournalGeobiology
Volume8
Issue number5
DOIs
Publication statusPublished - Dec 2010

Abstract

The weathering of volcanic minerals makes a significant contribution to the global silicate weathering budget, influencing carbon dioxide drawdown and long-term climate control. Basalt rocks may account for over 30% of the global carbon dioxide drawdown in silicate weathering. Micro-organisms are known to play a role in rock weathering yet the genomics and genetics of biological rock weathering are unknown. We apply DNA microarray technology to determine putative genes involved in weathering using the heavy metal-resistant organism, Cupriavidus metallidurans CH34; in particular we investigate the sequestering of iron. The results show that the bacterium does not depend on siderophores. Instead, the up-regulation of porins and transporters which are employed concomitantly with genes associated with biofilm formation suggests that novel passive and active iron uptake systems are involved. We hypothesize that these mechanisms induce rock weathering by changes in chemical equilibrium at the microbe-mineral interface, reducing the saturation state of iron. We also demonstrate that low concentrations of metals in the basalt induce heavy metal-resistant genes. Some of the earliest environments on the Earth were volcanic. Therefore, these results not only elucidate the mechanisms by which micro-organisms might have sequestered nutrients on the early Earth but also provide an explanation for the evolution of multiple heavy metal resistance genes long before the creation of contaminated industrial biotopes by human activity.

    Research areas

  • ALCALIGENES-EUTROPHUS CH34, HEAVY-METAL RESISTANCE, ESCHERICHIA-COLI, CUPRIAVIDUS-METALLIDURANS, RALSTONIA-EUTROPHA, BIOFILM FORMATION, FERROZINE METHOD, STRAIN CH34, IRON UPTAKE, SIDEROPHORES

ID: 1495689