Microbial rhodopsins are major contributors to the solar energy captured in the sea

TY - JOUR

T1 - Microbial rhodopsins are major contributors to the solar energy captured in the sea

AU - Gómez-Consarnau, Laura

AU - Raven, John A.

AU - Levine, Naomi M.

AU - Cutter, Lynda S.

AU - Wang, Deli

AU - Seegers, Brian

AU - Arístegui, Javier

AU - Fuhrman, Jed A.

AU - Gasol, Josep M.

AU - Sañudo-Wilhelmy, Sergio A.

N1 - This project was founded by the Marie Curie Actions–International Outgoing Fellowships (project 253970), the U.S. National Science Foundation grant OCE1335269, the Simons Foundation award 509727, and the Gordon and Betty Moore Foundation Marine Microbiology Initiative award 3779. J.A. and J.M.G. were supported by the Spanish project HOTMIX (CTM2011-30010-C02-MAR). The University of Dundee is a registered Scottish charity, no. SC015096.

PY - 2019/8/7

Y1 - 2019/8/7

N2 - All known phototrophic metabolisms on Earth rely on one of three categories of energy-converting pigments: chlorophyll-a (rarely -d), bacteriochlorophyll-a (rarely -b), and retinal, which is the chromophore in rhodopsins. While the significance of chlorophylls in solar energy capture has been studied for decades, the contribution of retinal-based phototrophy to this process remains largely unexplored. We report the first vertical distributions of the three energy-converting pigments measured along a contrasting nutrient gradient through the Mediterranean Sea and the Atlantic Ocean. The highest rhodopsin concentrations were observed above the deep chlorophyll-a maxima, and their geographical distribution tended to be inversely related to that of chlorophyll-a. We further show that proton-pumping proteorhodopsins potentially absorb as much light energy as chlorophyll-a-based phototrophy and that this energy is sufficient to sustain bacterial basal metabolism. This suggests that proteorhodopsins are a major energy-transducing mechanism to harvest solar energy in the surface ocean.

AB - All known phototrophic metabolisms on Earth rely on one of three categories of energy-converting pigments: chlorophyll-a (rarely -d), bacteriochlorophyll-a (rarely -b), and retinal, which is the chromophore in rhodopsins. While the significance of chlorophylls in solar energy capture has been studied for decades, the contribution of retinal-based phototrophy to this process remains largely unexplored. We report the first vertical distributions of the three energy-converting pigments measured along a contrasting nutrient gradient through the Mediterranean Sea and the Atlantic Ocean. The highest rhodopsin concentrations were observed above the deep chlorophyll-a maxima, and their geographical distribution tended to be inversely related to that of chlorophyll-a. We further show that proton-pumping proteorhodopsins potentially absorb as much light energy as chlorophyll-a-based phototrophy and that this energy is sufficient to sustain bacterial basal metabolism. This suggests that proteorhodopsins are a major energy-transducing mechanism to harvest solar energy in the surface ocean.

UR - https://www.scopus.com/pages/publications/85071634158

U2 - 10.1126/sciadv.aaw8855

DO - 10.1126/sciadv.aaw8855

M3 - Article

C2 - 31457093

SN - 2375-2548

VL - 5

SP - 1

EP - 8

JO - Science Advances

JF - Science Advances

IS - 8

M1 - eaaw8855

ER -