Dose-dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes: Implications for the carbon cycle
Diatoms and other phytoplankton play a crucial role in the global carbon cycle, fixing CO[subscript 2] into organic carbon, which may then be exported to depth via sinking particles. The molecular diversity of this organic carbon is vast and many highly bioactive molecules have been identified. Poly...
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| Format: | Article |
| Language: | en_US |
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National Academy of Sciences (U.S.)
2016
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| Online Access: | http://hdl.handle.net/1721.1/100586 https://orcid.org/0000-0001-9858-9834 |
| _version_ | 1826190008185257984 |
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| author | Bidle, Kay D. Van Mooy, Benjamin A. S. Edwards, Bethanie Rachele |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Bidle, Kay D. Van Mooy, Benjamin A. S. Edwards, Bethanie Rachele |
| author_sort | Bidle, Kay D. |
| collection | MIT |
| description | Diatoms and other phytoplankton play a crucial role in the global carbon cycle, fixing CO[subscript 2] into organic carbon, which may then be exported to depth via sinking particles. The molecular diversity of this organic carbon is vast and many highly bioactive molecules have been identified. Polyunsaturated aldehydes (PUAs) are bioactive on various levels of the marine food web, and yet the potential for these molecules to affect the fate of organic carbon produced by diatoms remains an open question. In this study, the effects of PUAs on the natural microbial assemblages associated with sinking particles were investigated. Sinking particles were collected from 150 m in the water column and exposed to varying concentrations of PUAs in dark incubations over 24 h. PUA doses ranging from 1 to 10 µM stimulated respiration, organic matter hydrolysis, and cell growth by bacteria associated with sinking particles. PUA dosages near 100 µM appeared to be toxic, resulting in decreased bacterial cell abundance and metabolism, as well as pronounced shifts in bacterial community composition. Sinking particles were hot spots for PUA production that contained concentrations within the stimulatory micromolar range in contrast to previously reported picomolar concentrations of these compounds in bulk seawater. This suggests PUAs produced in situ stimulate the remineralization of phytoplankton-derived sinking organic matter, decreasing carbon export efficiency, and shoaling the average depths of nutrient regeneration. Our results are consistent with a “bioactivity hypothesis” for explaining variations in carbon export efficiency in the oceans. |
| first_indexed | 2024-09-23T08:33:36Z |
| format | Article |
| id | mit-1721.1/100586 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:33:36Z |
| publishDate | 2016 |
| publisher | National Academy of Sciences (U.S.) |
| record_format | dspace |
| spelling | mit-1721.1/1005862022-09-23T12:55:41Z Dose-dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes: Implications for the carbon cycle Bidle, Kay D. Van Mooy, Benjamin A. S. Edwards, Bethanie Rachele Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Woods Hole Oceanographic Institution Edwards, Bethanie Rachele Diatoms and other phytoplankton play a crucial role in the global carbon cycle, fixing CO[subscript 2] into organic carbon, which may then be exported to depth via sinking particles. The molecular diversity of this organic carbon is vast and many highly bioactive molecules have been identified. Polyunsaturated aldehydes (PUAs) are bioactive on various levels of the marine food web, and yet the potential for these molecules to affect the fate of organic carbon produced by diatoms remains an open question. In this study, the effects of PUAs on the natural microbial assemblages associated with sinking particles were investigated. Sinking particles were collected from 150 m in the water column and exposed to varying concentrations of PUAs in dark incubations over 24 h. PUA doses ranging from 1 to 10 µM stimulated respiration, organic matter hydrolysis, and cell growth by bacteria associated with sinking particles. PUA dosages near 100 µM appeared to be toxic, resulting in decreased bacterial cell abundance and metabolism, as well as pronounced shifts in bacterial community composition. Sinking particles were hot spots for PUA production that contained concentrations within the stimulatory micromolar range in contrast to previously reported picomolar concentrations of these compounds in bulk seawater. This suggests PUAs produced in situ stimulate the remineralization of phytoplankton-derived sinking organic matter, decreasing carbon export efficiency, and shoaling the average depths of nutrient regeneration. Our results are consistent with a “bioactivity hypothesis” for explaining variations in carbon export efficiency in the oceans. 2016-01-04T18:18:09Z 2016-01-04T18:18:09Z 2015-05 2014-12 Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/100586 Edwards, Bethanie R., Kay D. Bidle, and Benjamin A. S. Van Mooy. “Dose-Dependent Regulation of Microbial Activity on Sinking Particles by Polyunsaturated Aldehydes: Implications for the Carbon Cycle.” Proc Natl Acad Sci USA 112, no. 19 (April 27, 2015): 5909–5914. https://orcid.org/0000-0001-9858-9834 en_US http://dx.doi.org/10.1073/pnas.1422664112 Proceedings of the National Academy of Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences (U.S.) American Meteorological Society |
| spellingShingle | Bidle, Kay D. Van Mooy, Benjamin A. S. Edwards, Bethanie Rachele Dose-dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes: Implications for the carbon cycle |
| title | Dose-dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes: Implications for the carbon cycle |
| title_full | Dose-dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes: Implications for the carbon cycle |
| title_fullStr | Dose-dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes: Implications for the carbon cycle |
| title_full_unstemmed | Dose-dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes: Implications for the carbon cycle |
| title_short | Dose-dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes: Implications for the carbon cycle |
| title_sort | dose dependent regulation of microbial activity on sinking particles by polyunsaturated aldehydes implications for the carbon cycle |
| url | http://hdl.handle.net/1721.1/100586 https://orcid.org/0000-0001-9858-9834 |
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