NYU Abu Dhabi researcher pitches in on algae-based fuel research

An Abu Dhabi-based researcher could help unlock the secret to an algae-based fuel source.
Pond scum may seem like an unpromising research subject. But for decades Chlamydomonas, a genus of tiny, single-celled plants that live in fresh water, oceans and even snow, has been used to study the fundamental biological processes: how cells respond to light, each other and their environment.

It has gained favour in recent years as scientists have realised the potential of the triglyceride fatty acids the algae produce, which could eventually become an economically viable biodiesel.

The fast-growing algae quickly make the lipid deposits using sunlight, carbon dioxide and little else, making it an attractive alternative source of fuel.

Researchers are racing to engineer algae that make the best use of photosynthetic energy to produce the lipids, desperate to understand the organisms' genetics and metabolism.

The US department of energy has dozens of algal genome-sequencing projects under way, hoping to decipher gene transcripts and protein expressions to make algal biofuel cost-effective.

It is joined by biotech companies eager to capitalise on the organisms' potential for turning greenhouse gas and organic material into diesel.

But manipulating the genes of even the best-understood genus, Chlamydomonas, has proved difficult and costly.

With about 1,000 genes controlling the algae's metabolism and ability to process sunlight, there are billions of possible gene combinations that could affect its industrial potential.

Now a team of scientists, including a researcher at NYU Abu Dhabi, have developed what they say is the first genome-scale system of mapping the species, enabling them to simulate deletions and substitutions of genes.

"It allows us to basically carry out experiments on a computer that are otherwise certainly not things you could easily guess or completely carry out experimentally," says Dr Kourosh Salehi-Ashtiani.

Dr Salehi-Ashtiani is conducting molecular biology research at NYU Abu Dhabi and for the Centre for Genomics and Systems Biology at the university's New York campus.

He collaborated on the project with researchers from Harvard University, the University of Virginia, the University of California, Dana-Farber Cancer Institute and the University of Iceland.

The results were published this month in the journal Nature.

The computer model allows researchers to factor in the use of light energy when looking at growth characteristics.

In that way, they can determine how a combination of genes would trigger different reactions to varying light sources or amounts.

"How the species behaves in terms of light is of the most importance in terms of looking at its use in bioenergy, because you are relying on the light to generate biomass," says Dr Salehi-Ashtiani.

"If the focus is to grow algae in a way that optimises production of these lipids, then this is obviously an important part of that."

Algal biofuel has shown promise for decades. Researchers had all but given up on it because producing large volumes of its lipids is not economical. But the falling cost of gene sequencing has given them reason to revisit it.

The Human Genome Project, which identified and mapped about 25,000 genes in the human, cost an estimated US$3 billion (Dh11.01bn) and took about 13 years.

Now machines can process a human genome in about 10 days for $10,000.

"In just five years there have been huge opportunities opening up in terms of sequencing because of this price drop and faster results, and that has opened doors for research," says Dr Salehi-Ashtiani.

Besides engineering the best lipid-producing algae, scientists can also consider broader questions about single-cell organisms such as their relationships with other, more distantly related organisms.

Chlamydomonas has long been used as a model for understanding the genes of single-celled organisms, but Dr Salehi-Ashtiani plans to expand the sequencing to other algae from labs to be built in Abu Dhabi.

He is most interested in algal variations around the globe. A large part of its appeal for biofuel is that it can be cultivated on land that is not suitable for agriculture, including large open ponds and deserts. Many species can thrive in seawater or even wastewater from treatment plants.

Working with other researchers, Dr Salehi-Ashtiani would study strains of the genus in 20 or 30 locations around the world to understand how the genome varies in different environments.

By recognising differences in the sequences, he can use the computer model to better understand natural mutations in the genomes.

"Let's say you have a strain somewhere that grows slow but produces a lot of lipids," Dr Salehi-Ashtiani says.

"You can ask the computer model whether these mutations are expected to decrease growth rates of lipids, and help to interpret why that might be. This is key to developing algal-based renewable energy."

The next step, he says, would be to study marine algae that is native to the UAE or would survive in the Gulf's climate, which would presumably make the most of the intense sunlight.

"If there was interest in developing a programme in the Middle East, this would be the first step for finding the right algae that would thrive in the right environmental conditions," Dr Salehi-Ashtiani says.



Published: August 14, 2011 04:00 AM


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