CRENARC · Functional diversity of Crenarchaeota in aquatic ecosystems
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2007-09-01 → 2009-08-31
- EU contribution
- €146,366
- Participants
- 1
- Scheme
- EIF
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - CRENARC (Functional diversity of Crenarchaeota in aquatic ecosystems)
Microbes are abundant and ubiquitous component of aquatic ecosystems, and through their role in biogeochemical cycling, they can influence the earth's oceanic and atmospheric composition. Little is known, however, about the factors that influence the activity and dynamics of microbial communities. The main goal of our research project was to determine the diversity and function of Crenarchaeota in aquatic ecosystems. Crenarchaeota is a phylum of Archaea (the third domain of life) widely represented in the world's oceans but which role in the ecosystem remains poorly understood. Recent findings indicate that Crenarchaeota are involved in ammonium oxidation and CO2 fixation, suggesting a major role for the group in the biogeochemical cycles of nitrogen and carbon. The project chose to work simultaneously on different approaches to better cover the different aspects of the functional diversity of Crenarchaeota in aquatic ecosystems. The main approaches involved the study of the temporal dynamic of crenarchaeotal communities through long term monitoring of microbial abundance, and the detailed description of crenarchaeotal assemblages via high throughput sequencing. The work carried out showed that in the coastal Mediterranean Sea Crenarchaeota had a marked seasonal dynamics that reoccurred year after year. Their abundance was highest during winter and significantly correlated with nitrite and archaeal ammonia monooxygenase (amoA) gene involved in ammonia oxidation. The close association between Crenarchaeota and a major ecosystem processes indicates that Crenarchaeota may play an important ecological role in the coastal Mediterranean Sea. Further, by using the new pyrocequencing technology the project could report a very detailed description of Archaea communities in the deep Arctic Ocean. It showed that Crenarchaeota were always an important component of the deep Arctic but that the communities differed from one water mass to the other. It concluded that water masses probably act as physical barriers limiting the dispersal and controlling the diversity of Archaea in the ocean. This suggests that it is essential to consider the coupling between microbial and physical oceanography to fully understand the diversity and function of marine microbes.
Data: CORDIS, © European Union
Project objective
Archaea are prokaryotic microorganims that constitute the third phylogenetic domain of life. Up to recently Archaea were thought to be mostly restricted to extreme environments but it has recently been established that the biodiversity and metabolic capabilities of the phylum Crenarchaeota is substantially larger than previously assumed.Recent evidence suggests that ubiquitous pelagic Crenarchaeota play an essential role in biogeochemical cycling in aquatic ecosystems. It is, however, unknown which crenarchaeotal groups are participating, to which extent, and under which environmental conditions.Recent findings suggest that marine and freshwater Crenarchaeota could act as chemoautotrophs and fix inorganic carbon in the dark. The project CRENARC will focus on the possible role of Crenarchaeota in fixing carbon in aquatic ecosystems using a fresh water lake and a coastal marine site as model ecosystems.The proposed research requires a molecular ecological approach using high-resolution technologies. We will perform stable isotopic probing (SIP) to monitor the assimilation of 13C-labelled substrate by Crenarchaeota and we will apply molecular ecological methods to analyse the labelled DNA/RNA. DNA/RNA sequences will be screened for both phylogenetic marker and functional genes.We will also develop metagenomic technologies to clone large labelled crenarchaeotal DNA fragments. Consecutive sequencing and gene screening combined with comparative genomics will increase our understanding of the ecological role and p hylogenetic diversity of Crenarchaeota.It is foreseen that CRENARC will result in a substantially increased understanding of the role of this enigmatic group of aquatic prokaryotes in biogeochemical cycling.
Original text from CORDIS.
Participants
- CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS · MADRIDCoordinatorSpain
Links
Data: CORDIS, © European Union