Published on March 30th, 2010 | by Steve Savage4
The Genetics of Fighting Climate Change: Part 1
I just had an opportunity to attend a conference sponsored by the Department of Energy (DOE) about how the fast-moving new science of “Genomics” is being used to help understand the biological effects of climate change and how genomics is being used in the effort to reduce dependence on fossil fuels. At this meeting, scientists from a wide range of fields came together with the genomics experts at the Joint Genomics Institute (JGI) in Walnut Creek, California to talk about their research. JGI is a government-funded lab. Normally, the diverse scientists mail samples of DNA to the JGI and the JGI sends back massive files of information on the sequences that were in the samples. At this annual meeting they get to meet face to face.
What JGI can do today and what the scientists can learn from the data is remarkable. The Human Genome Project that started in 1990 took 13 years to get the full DNA sequence of one human’s 23 chromosomes (>3 million “base pairs” representing 20-25,000 different genes). To show how far this science has come, the current human genetics goal is to sequence the genomes of 1000 different people for comparison, and that process will take a small fraction of the time and money vs the original project.
I’d like to describe just a few of the ways I heard that scientists are harnessing the “horsepower” of these new genomics tools to address important issues surrounding climate change. This post will focus on the biofuel aspects, and a following post will focus on how genomics are being used to understand the complex biology of climate change.
Genomics and the Development of Advanced Biofuel Crops
Many research groups in the private and public sector are working out the genetics of next generation biofuel crops like Switchgrass, Miscanthus, and Fiber Sorghum. Another group is working with various wild sunflower species from the desert southwest that can by hybridized and turned into non-flowering crops in Northern lattitudes where they produce massive woody stalks full of potential bio-energy (something I learned about for the first time at this meeting). In most cases these represent minimally domesticated crops, but with the tools of genomics their yield, stress tolerance and pest resistance can be rapidly improved. The genetics of flowering are also being examined so that, where necessary, the new crop can be grown with no danger of unwanted gene transfer in nature. Because even seemingly different plants share many of the same genes and metabolic pathways, the extensive genomics progress with food crops (e.g. rice, corn, soybeans…) is also aiding this process. All of this will also help with the woody biofuel options like Poplar and Eucalyptus.
Other scientists are using genomics tools to understand how wild plant populations adapt to their environment – something that will give clues about how to make the new bioenergy crops more robust. All together, the science of genomics will take decades out of the process of developing advanced bioenergy crops.
How to Get From Cellulose to Sugars
One of the biggest challenges for biomass-based energy is breaking down the ligno-cellulosic crop material into the sugars that can then be converted into transportation fuels. This is something that nature does routinely with special populations of bacteria that live in something like a termite’s “hind gut” or a cow’s rumen. The problem has been that scientists have not been able to study these bacteria very easily because they can’t normally be grown in the lab. A group at JGI reported on the progress they have made using genomics data generated by sequencing the bacterial genes from cow rumen samples. They have been able to identify many genes for previously unknown versions of the enzymes that will be needed for a biomass to fuel industry. These powerful genomic tools are thus unlocking the secrets behind how nature taps into the world’s most abundant biological forms of stored solar energy like cellulose.
How to Get From Sugars to Fuel
There was a fascinating presentation about how sophisticated understanding of genetics and metabolism are allowing scientists to develop the microbes that can make biofuels other than ethanol (esters, short chain alcohols, alkanes…) that are more compatible with the trillions of dollars worth of infrastructure already in place for fossil fuels from pipelines to engines. Cellulosic biofuels will be much more than ethanol in the future.
This is Going to Take More Than Genetics
Interestingly, this meeting was not just about genetics. There were several talks about how to predict and control the environmental and economic impacts of bioenergy crops (greenhouse gas profile, nitrogen cycle effects, grower economics, food vs fuel issues, indirect land-use change…). I was impressed with the holistic view being considered by even the most basic scientists in this field. My talk was about what we can learn from the adoption (and unfortunately all-too-common non-adoption) of “no-till” farming in terms of practical barriers to large-scale adoption of new energy crops. It was received with much interest.
I don’t want to present an overly optimistic view of next generation biofuels. There are a lot of non-trivial challenges from the technical and practical side, but I’m an optimist about the long-term potential – in part because of the power of the science of genomics. I’m less comfortable with the public policy side (tariffs, subsidies, mandates…) because those decision processes don’t involve much intellectual/economic/environmental rigor. Maybe we need more scientists to run for office?
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DNA Image from Wikimedia Commons. Miscanthus image from Tony Atkin.