Biotic and Abiotic Lability of Terrestrial Organic Matter in Seawater
PI MIO : Jean François Rontani
MIO participants J-F Rontani, P. Bonin, S. Guasco, F. Vaultier and A. Portas
PartnerCEREGE (O. Radakovitch)
The project BALTOMS (2017-2019) is funded by Labex OT-MED.
It focuses onstudy of the biotic degradation of terrestrial OM (MOPT) discharged by rivers into the sea. Until recently, this MOPT was considered resistant to degradation, whereas in fact it undergoes intense biotic and abiotic degradation in estuaries.
Main results obtained
- Degradation of MOPT favoured at high salinity (change in the structure of bacterial communities → selection of bacteria that degrade MOPT more effectively).
- Degradation of MOPT accelerated in the presence of potamoplankton (priming effect) (assimilation of recalcitrant substrates (MOPT) favoured in the presence of easily assimilable co-substrates (freshwater diatoms)).
- In situ confirmation (evidence of a priming effect induced by marine diatoms).
- DNA/RNA isotope labelling of communities adapted to the degradation of marine MOPT/MO is currently being carried out (DNA - SIP) in order to identify the bacteria involved in the degradation of MOPT.
Publications
- M2 internship report by M-H. PRIME (2017)
- Bonin P., Prime A-H., Galeron M-A., Guasco S. and Rontani J-F. (2019) Enhancement of biotic degradation of terrestrial particulate organic matter in an estuarine salinity gradient: Interactive effects of organic matter pools and changes of bacterial communities. Aquatic Microbial Ecology 83: 147-159.
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