Abstract
The weathering of silicate in the world's critical-zone (rock-soil interface) is a natural mechanism providing a feedback on atmospheric CO2 concentrations through the carbonate-silicate cycle. We examined culturable bacterial communities from a critical-zone in western Iceland to determine the optimum growth temperature and their ability to solubilize phosphate-containing minerals, which are abundant within the critical-zone area examined here. The majority of isolated bacteria were able to solubilize mineral-state phosphate. Almost all bacterial isolates were mesophilic (growth optima of 20-45 degrees C), despite critical-zone temperatures that were continuously below 15 degrees C, although all isolates could grow at temperatures associated with the critical-zone (-2.8-13.1 degrees C). Only three isolates were shown to have thermal optima for growth that were within temperatures experienced at the critical-zone. These findings show that the bacteria that inhabit the western Icelandic critical-zone have temperature growth optima suboptimally adapted to their environment, implying that other adaptations may be more important for their long-term persistance in this environment. Moreover, our study showed that the cold basaltic critical-zone is a region of active phosphate mineral-weathering.
Original language | English |
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Pages (from-to) | 52-62 |
Number of pages | 11 |
Journal | Geomicrobiology journal |
Volume | 33 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2 Jan 2016 |
Keywords / Materials (for Non-textual outputs)
- bacteria
- critical-zone
- MPS
- soil microbiology
- weathering
- PHOSPHATE-SOLUBILIZING BACTERIA
- 16S RIBOSOMAL-RNA
- SILICATE ROCKS
- TEMPERATURE
- SOIL
- PLANTS
- GENES
- RATES
- ICELAND
- GROWTH