Abstract
Organic matter (OM) transformations in marine sediments play a crucial role in the global carbon cycle. However, secondary production and priming have been ignored in marine biogeochemistry. By incubating shelf sediments with various 13C-labeled algal substrates for 400 days, we show that ~65% of the lipids and ~20% of the proteins were mineralized by numerically minor heterotrophic bacteria as revealed by RNA stable isotope probing. Up to 11% of carbon from the algal lipids was transformed into the biomass of secondary producers as indicated by 13C incorporation in amino acids. This biomass turned over throughout the experiment, corresponding to dynamic microbial shifts. Algal lipid addition accelerated indigenous OM degradation by 2.5 to 6 times. This priming was driven by diverse heterotrophic bacteria and sulfur- and iron-cycling bacteria and, in turn, resulted in extra secondary production, which exceeded that stimulated by added substrates. These interactions between degradation, secondary production, and priming govern the eventual fate of OM in marine sediments.
| Original language | English |
|---|---|
| Article number | eadm8096 |
| Pages (from-to) | 1-10 |
| Number of pages | 10 |
| Journal | Science advances |
| Volume | 10 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - 17 May 2024 |
Bibliographical note
Publisher Copyright:© 2024 the Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. no claim to original U.S. Government Works. distributed under a creative commons Attribution license 4.0 (cc BY).
Funding
We thank C. R\u00F6ttgen for providing laboratory support. This study was supported by DFG under Germany\u2019s Excellence Strategy, no. EXC-2077-390741603.
| Funders | Funder number |
|---|---|
| Deutsche Forschungsgemeinschaft | EXC-2077-390741603 |
| Deutsche Forschungsgemeinschaft |
