RT Journal Article
SR Electronic
T1 Marine proteorhodopsins rival photosynthesis in solar energy capture
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 231167
DO 10.1101/231167
A1 Laura Gómez-Consarnau
A1 Naomi M. Levine
A1 Lynda S. Cutter
A1 Deli Wang
A1 Brian Seegers
A1 Javier Arístegui
A1 Jed A. Fuhrman
A1 Josep M. Gasol
A1 Sergio A. Sañudo-Wilhelmy
YR 2018
UL http://biorxiv.org/content/early/2018/04/10/231167.abstract
AB All known phototrophic metabolisms on Earth are based on one of three energy-converting pigments: chlorophyll-a, bacteriochlorophyll-a, and retinal, which is the chromophore in rhodopsins [1]. While the contribution of chlorophylls to global energy flows and marine carbon cycling has been studied for decades, the role of retinal-based phototrophy remains largely unexplored [1,2]. We report the first vertical distributions of the three energy-converting pigments measured along a contrasting nutrient gradient through the Mediterranean Sea and the Eastern Atlantic Ocean. The highest proteorhodopsin 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 proteorhodopsins potentially absorb as much or more light energy than chlorophyll-a –based phototrophy and this energy is sufficient to sustain bacterial basal metabolism. Our results suggest that ubiquitous proteorhodopsin-containing heterotrophs are important contributors to the light energy captured in the sea.