Dr. Jarone Pinhassi, a scientist in marine microbiology at Linnaeus University, Sweden said, “It was long thought that phytoplankton were the only organisms in the sea that could harvest the energy from sunlight for growth.”  An exciting new finding by scientists in Sweden and Spain that teamed up has been published in the online, open access (freely available) journal PLoS Biology saying bacteria in the ocean can harvest light energy from sunlight to promote survival thanks to a unique ‘photoprotein’.

These microscopic planktonic organisms carry out the same chlorophyll driven photosynthesis process as green plants on land.

Proteorhodopsin Containing Bacteria. Click image for more info.

American scientists discovered in 2000 that many marine bacteria contain a gene in their genome that encodes a new kind of light-harvesting pigment: proteorhodopsin.  Proteorhodopsins are membrane-embedded, light-driven proton pump proteins that allow harvesting of energy from sunlight and are related to the pigment in the retina that enables human vision in less intense light.

Now the first direct evidence for the functioning of proteorhodopsin in native marine bacteria is being presented, based on mutational analysis in a marine bacterium. At the same time the Swedish and Spanish study shows that proteorhodopsin-mediated phototrophy, the process of acquiring energy from light, allows marine bacteria to better survive periods of starvation in nutrient-depleted ocean zones.

Pinhassi explains, “Bacteria in the surface ocean are swimming in a sea of light, and it may not be all that surprising that evolution has favored microorganisms that can use this abundant energy source.”  If one considers that a liter of seawater on average contains around a billion bacteria, many of which contain proteorhodopsin, it becomes important and worthwhile to understand the novel mechanisms for marine bacteria to efficiently use solar energy.  The activity of these bacteria play a crucial role in the global carbon cycle by determining oceanic production of CO² through respiration and determining how the fluxes of energy that are fixed by photosynthesis are channeled through marine food chains.

“Bacteria in the surface ocean are swimming in a sea of light, and it may not be all that surprising that evolution has favored microorganisms that can use this abundant energy source,” says Pinhassi.

While the first impulse on this news might not be a major jolt, the implications and the potential possibilities cause considerable fascination.  The Swedish and Spanish team has come upon methods that serve to show how the bacteria are using the genes and feeding their lives without photosynthesis.  At a decade in the knowledge inventory, the gene builders could now have new routes to harvesting solar energy.

What, where, how and when the gene can be expressed could serve organism engineering in ways yet to be dreamed of.  This is the first light on a newly discovered light to bio fuel path.  It may even give algae some competition someday.


2 Comments so far

  1. Al Fin on May 10, 2010 7:20 AM

    Fascinating. All these bacteria gobbling up atmospheric carbon like they could never get enough — and “climate scientists” had no idea.

    We only know about 10% or less of what we need to know to devise a halfway decent climate model. The rest is just guesswork.

    And since the “climate scientist’s” (and their sponsors’ ideological bias) financial well-being depends upon an impending climate catastrophe, that is just what the models keep telling us is going to happen.

  2. physical therapist on November 8, 2010 9:48 AM

    Couldnt agree more with that, very attractive article

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