An unknown respiration pathwaysubstantially contributes to soil CO2 emissions.
2012
Maire, Vincent | ALVAREZ, Gaël | Colombet, J | Comby, Aurélie | Despinasse, Romain | Dubreucq, Eric | Joly, M | Lehours, AC | Perrier, V | Shahzad, Tanvir | Fontaine, Sébastien
The respiratory release of CO2 from soils is a major determinant of the global carbon cycle. It is traditionally considered that this respiration is an intracellular metabolism consisting of complex biochemical reactions carried out by numerous enzymes and 5 co-factors. Here we show that the intracellular enzymes released from dead organisms are stabilized in soils and have access to suitable substrates and co-factors to permit function. These enzymes reconstitute an extracellular oxidative metabolism (Exomet) that may substantially contribute to soil respiration (16 to 48% of CO2 released from soils in the present study). Exomet and respiration from living organisms should be 10 considered separately when studying effects of environmental factors on the C cycle because Exomet shows specific properties such as resistance to high temperature and toxics.
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