Project description:Measure changes in dissolved organic matter composition and resulting microbial decomposition rates in an experimentally warmed peatland.
2021-05-27 | PXD019912 | Pride
Project description:Long-term manuring enhanced soil organic carbon in red soils via copiotrophic microbial synthesis of recalcitrant dissolved organic matter compounds
Project description:Drought represents a significant stress to microorganisms and is known to reduce microbial activity and organic matter decomposition in Mediterranean ecosystems. However, we lack a detailed understanding of the drought stress response of microbial decomposers. Here we present metatranscriptomic data on the physiological response of in situ microbial communities on plant litter to long-term drought in Californian grass and shrub ecosystems.
Project description:Oxygen minimum zones (OMZs) are expanding due to increased sea surface temperatures, subsequent increased oxygen demand through respiration, reduced oxygen solubility, and thermal stratification driven in part by anthropogenic climate change. Devil's Hole, Bermuda is a model ecosystem to study OMZ microbial biogeochemistry because the formation and subsequent overturn of the suboxic zone occur annually. During thermally driven stratification, suboxic conditions develop, with organic matter and nutrients accumulating at depth. In this study, the bioavailability of the accumulated dissolved organic carbon (DOC) and the microbial community response to reoxygenation of suboxic waters was assessed using a simulated overturn experiment. The surface inoculated prokaryotic community responded to the deep (formerly suboxic) 0.2 μm filtrate with cell densities increasing 2.5-fold over 6 days while removing 5 μmol L<sup>-1</sup> of DOC. After 12 days, the surface community began to shift, and DOC quality became less diagenetically altered along with an increase in SAR202, a Chloroflexi that can degrade recalcitrant dissolved organic matter (DOM). Labile DOC production after 12 days coincided with an increase of <i>Nitrosopumilales,</i> a chemoautotrophic ammonia oxidizing archaea (AOA) that converts ammonia to nitrite based on the ammonia monooxygenase (<i>amoA</i>) gene copy number and nutrient data. In comparison, the inoculation of the deep anaerobic prokaryotic community into surface 0.2 μm filtrate demonstrated a die-off of 25.5% of the initial inoculum community followed by a 1.5-fold increase in cell densities over 6 days. Within 2 days, the prokaryotic community shifted from a <i>Chlorobiales</i> dominated assemblage to a surface-like heterotrophic community devoid of <i>Chlorobiales</i>. The DOM quality changed to less diagenetically altered material and coincided with an increase in the ribulose-1,5-bisphosphate carboxylase/oxygenase form I (<i>cbbL</i>) gene number followed by an influx of labile DOM. Upon reoxygenation, the deep DOM that accumulated under suboxic conditions is bioavailable to surface prokaryotes that utilize the accumulated DOC initially before switching to a community that can both produce labile DOM via chemoautotrophy and degrade the more recalcitrant DOM.
2024-02-27 | MTBLS8122 | MetaboLights
Project description:Heterotroph response to phytoplankton dissolved organic matter
| PRJNA678611 | ENA
Project description:Biogenesis of marine recalcitrant dissolved organic carbon and its environmental effects