Sequencing Algae DNA For Biofuels

 By Benjamin Plackett

There’s an ancient group of algae that lived in the oceans before our evolutionary ancestors even became land-dwellers. They are so numerous that their blooms influence weather patterns. They also account for up to 40 percent of all the photosynthesis that happens in seawaters. Until recently, scientists haven’t really known a lot about their DNA. But in a new study, researchers at the University of Washington have sequenced the entire library of genes in one of these algae species and the information gained could help biofuel production…

The science of decoding an organism’s whole genetic library, known as a genome, is a testament to the power of modern technology in the field of biology. The technique has rapidly progressed from an extraordinary, yet cumbersome, process to one of relative ease and speed.

We can now sequence the entire genetic makeup of a human in just 26 hours. But despite advances in genetic technology, it took a group of scientists at the University of Washington three years to sequence the DNA of a much simpler, single-cell organism.

In a research paper recently published in the journal PLOS Genetics, the scientists described how they sequenced the genome of an algal species. The main reason they held their patience for so long was the alluring potential of using the decoded DNA for better biofuel production. “Transcribing and copying the genetic code was pretty easy,” says lead study author Bake Hovde, “But figuring out what it does took a lot of work.” The species they studied is called Chrysochromulina tobin.

Finding where one gene ends and another begins in the vast sequence they unravelled took Hovde and his colleagues a long time, longer than it takes with humans, because there’s been so little previous research on decoding the genes of algae in general.

That meant they didn’t have a list of suggestions to work from, explains Hovde, like they would for most animals. But it was worth the years spent in labs, says Hovde, because their findings could help those trying to make biofuel from algae into a credible energy resource. There are two ways that knowing the algae’s DNA may help, he says.

Firstly, the specific species that Hovde decoded produces a lot of fatty acids, which are important for making biodiesel, but it doesn’t grow densely. Denser growth would mean a higher yield of the fatty acids, making biofuel more efficient and economically competitive.

Admittedly, biofuels still have a fairly long way to go before their price point makes them a viable renewable energy, but it's an endeavor worth chasing and with every piece of research we get closer

Researchers don’t really know why the algae won’t grow densely. “But one theory,” explains Hovde, “is that they have some sort of sense where they know they’re getting dense and stop.” If that’s the case then genetic modification could make them grow more compactly and therefore improve yield. “If we could dim that sense then that’s one line attack,” says Hovde.

Secondly, Chrysochromulina tobin not only produces more fatty acids, but the way it produces them is also convenient for biofuel production. The fatty acids in this algae species are concentrated into two areas, whereas in other species the acids are spread throughout the cell. If we isolate the genes that control the distribution of fatty acids and apply them to other species of algae that grow more densely, “That could potentially make it easier for harvest,” says Hovde.

Admittedly, biofuels still have a fairly long way to go before their price point makes them a viable renewable energy, but it’s an endeavor worth chasing and with every piece of research we get closer, says Hovde. “The plus for biofuel,” he explains, “is that we don’t have to redesign our infrastructure.” Cars, gas stations and engines are designed to take petrol and diesel—it’s a lot easier to find a renewable to work in that context than revolutionize the way cars, roads and gas pumps are designed, argue algae enthusiasts.

about the author
Benjamin Plackett
I’m a journalist based in London. I report on all things science, tech, and health for a number of different publications. My work has been published by The Daily Dot, Inside Science and CNN among others. I earned my M.A. in Journalism at New York University and my B.Sci in Biology from Imperial College, London.