RT Journal Article SR Electronic T1 Volatile Organic Compound Specialists in the Phycosphere JF bioRxiv FD Cold Spring Harbor Laboratory SP 2024.06.14.599129 DO 10.1101/2024.06.14.599129 A1 Padaki, Vaishnavi G. A1 Mayali, Xavier A1 Weber, Peter K. A1 Giovannoni, Stephen J. A1 Abraham, Kaylene A1 Jacobs, Kerry A1 Collart, Lindsay A1 Halsey, Kimberly H. YR 2024 UL http://biorxiv.org/content/early/2024/06/17/2024.06.14.599129.abstract AB Labile dissolved organic carbon (LDOC) in the oceans accounts for ∼ ¼ of global photosynthesis and turns over with a half-life of about one day, fueling one of the largest engines of microbial heterotrophic production on the planet. Volatile organic compounds (VOCs) are poorly constrained components of LDOC. We detected 78 VOCs totaling 18.5 μM in cultures of the model diatom Phaeodactylum tricornutum, including hydrocarbons usually found in petroleum. In five individual cocultures with bacteria adapted to grow with this diatom, 1 to 66 VOCs were depleted. Two of the most active VOC consumers, Marinobacter and Roseibium, had more VOC oxidation genes, and attached to the diatom, suggesting VOC specialism. Diatom photosynthesis increased by up to 29% in the presence of VOC consumers, indicating that VOC consumption by heterotrophic bacteria in the phycosphere – a region of rapid organic carbon oxidation that surrounds phytoplankton cells – could impact global rates of primary production.Competing Interest StatementThe authors have declared no competing interest.