Scientists Hack Early Stage Of Photosynthesis In Breakthrough For Biofuel

By Alex Kimani - Mar 27, 2023

• Algae biofuels have been abandoned due to the difficulty in making them economically competitive with crude oil.
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• Scientists have discovered a new process in photosynthesis that can extract electrons earlier than previously known, offering new possibilities in self-generating, self-repairing catalysts for renewable energy.
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• Using super-fast spectroscopic techniques, researchers were able to study photosynthesis at an ultrafast timescale, capturing images a million billion times faster than a typical smartphone.

Last month, Exxon Mobil (NYSE:XOM) pulled the plug on its 14-year-long algae biofuels project, becoming the last oil company to abandon what was once considered the fuel of the future.The whole idea was not without merit, though. Algae do have some clear advantages over other biofuel candidates, mainly because these photosynthetic microorganisms are super-efficient at converting sunlight into biomass; have high lipid content of up to 80% for some varieties and are more versatile than, say, corn, a common biofuel crop. 

Unfortunately, Exxon and its Big Oil cohorts discovered that it's too tough to make the economics of algae biofuels competitive with those of much cheaper crude, with algae-based bioproducts firm Cellana estimating that crude would have to hit ~$500/bbl for algae biofuels to compete successfully.

But a new discovery by scientists might offer companies like Exxon and renewable energy players a new lifeline. Scientists have “hacked” an early stage of photosynthesis and discovered new ways to extract energy from the process, a finding that could help in generating clean fuels and renewable energy.

Hacking Photosynthesis      

An international team of biologists, chemists and physicists, led by the University of Cambridge, has succeeded in studying photosynthesis at a molecular level and an ultrafast timescale: a millionth of a millionth of a second.

Although the process by which plants convert sunlight and water into energy has been known to man for centuries, the photophysics of the process, including the atomic and molecular changes that occur when a plant absorbs sunlight, is not well understood. A big challenge to fully understanding photosynthesis is that the process is way too fast for many traditional monitoring systems to track. To overcome this barrier, the Cambridge team developed a technique using super-fast spectroscopic techniques using laser pulses aimed at live cell samples to observe swift cellular changes.

According to study author Tomi Baikie, these lasers take “photos” of photosynthetic cells at a rate “...a million billion times faster than your iPhone. The (quantum) electronics of the plant world are pretty spectacular. We didn’t quite expect it to work--but it worked really, really well. This means we have a new tool to understand cells.” 

A key discovery by the team is that the electrons crucial to photosynthesis are extracted from cells much earlier than previously thought. Zhang and her colleagues were trying to understand how ring-shaped molecules called quinones are able to 'steal' electrons from the photosynthesis process. Quinones can accept and give away electrons easily. The scientists used ultrafast transient absorption spectroscopy to study how the quinones behave in photosynthetic cyanobacteria in real time.While there have been many attempts to “steal” electrons from photosynthesis in a timely fashion, “achieving this would open up many exciting possibilities where photosynthetic cells and their components can serve as self-generating, self-repairing catalysts that cannot be replicated by artificial systems,” study author Jenny Zhang told Earther in an email. The complication so far has been that researchers have not been able to ‘see’ where the electronics are being stolen from within the cells, Zhang added.  

If that sounds a bit byzantine and wonky, the big takeaway here is that this discovery is a potential game-changer with a range of future applications, from biofuels to developing more efficient crops, which could improve the competitiveness of future biofuels. Further, scientists have been studying how photosynthesis can be used to address the climate crisis, by mimicking the photosynthetic processes to generate clean fuels from just sunlight and water, for example. 

“All it takes is a few fundamental breakthroughs to completely change the field. Such breakthroughs require time, but also investment in fundamental science and interdisciplinary research. This work is a beautiful demonstration of this, we have changed the goal posts of which this technology can be,” Zhang said. 

By Alex Kimani for Oilprice.com