Inefficient microbial production of refractory dissolved organic matter in the ocean

Helena Osterholz, Jutta Niggemann, Helge-Ansgar Giebel, Meinhard Simon, Thorsten Dittmar
2015 Nature Communications  
Dissolved organic matter (DOM) in the oceans constitutes a major carbon pool involved in global biogeochemical cycles. More than 96% of the marine DOM resists microbial degradation for thousands of years. The composition of this refractory DOM (RDOM) exhibits a molecular signature ubiquitously detected in the deep oceans. Surprisingly efficient microbial transformation of labile into stable forms of DOM has been shown previously, implying that microorganisms apparently produce far more RDOM
more » ... needed to sustain the global pool. Here we show, by assessing the microbial formation and transformation of DOM in unprecedented molecular detail for 3 years, that most of the microbial DOM is different from RDOM in the ocean. Only o0.4% of the net community production is channelled into a form of DOM that is undistinguishable from oceanic RDOM. Our study provides a molecular background for global models on the production, turnover and accumulation of marine DOM.
doi:10.1038/ncomms8422 pmid:26084883 fatcat:xcgd74je35dknjyojxhgsz2st4