Groundbreaking Gene Scientist Is Taking His Craft to the Oceans

March 5, 2004

Dr. J. Craig Venter defied skeptical biologists by decoding the human genome in a scant three years. Now he has set his sights on an even grander goal - cataloging all the microbial life in the world.

Dr. Venter said yesterday that he and colleagues had discovered at least 1,800 new microbial species and more than 1.2 million genes by sequencing the DNA from a sample of seawater from the Sargasso Sea, off Bermuda. The findings revealed a diversity of life in the ocean that has not been seen until now.

"It's almost hyperbole," said David M. Karl, a professor of oceanography at the University of Hawaii who was not involved in the work. "How can you imagine one sample having a million new genes and proteins that we don't know anything about?"

Dr. Venter also announced at a Washington news conference yesterday that he has embarked on an expedition around the world partly inspired by Charles Darwin's voyage in the 1830's. His goal is to sample ocean water every 200 miles, as well as some spots on land, to search for microbes. His yacht, the Sorcerer II, is already in the Galápagos Islands and has been converted into a research vessel.

The Sargasso Sea findings, published online yesterday by the journal Science, represent perhaps the most dramatic example to date of how genomics is beginning to shake up environmental studies.

Normally, scientists try to understand microbes by growing them in laboratory cultures, but that has not been possible with more than 99 percent of the world's bacteria. Dr. Venter said his team extracted as much DNA as possible from the creatures without growing them in culture.

The gene sequences provide some clue as to how many different species are present and what they might look like. "Now with these new tools we can see what everyone has missed to date, which is the vast majority of life," Dr. Venter said.

He said that the 1.2 million genes discovered in the Sargasso Sea exceeds the total number of genes from all species in public databases, though only 70,000 of the genes are truly novel, as opposed to variations on existing genes. Humans have about 30,000 genes.

The sequences of all the discovered genes will be put into the public domain, he said. The goal, he said, is "a catalog of the earth's gene pool."

The team found nearly 800 new genes for proteins sensitive to light, suggesting that more bacteria than thought might be converting light into other types of energy.

The project, conducted at Dr. Venter's Institute for Biological Energy Alternatives, was financed in part by the Department of Energy, which hopes to harness microbes to help produce energy or clean pollution.

Some oceanographers said that the work so far has not taught them anything new, but has confirmed the variety of ocean life and provide a giant parts list that would be studied for years to come.

"He's allowed us for the first time to see that diversity," said Stephen Giovannoni, a professor at Oregon State University who studies microbes in the Sargasso Sea.

Dr. Venter has a history of shaking up the scientific establishment and attracting great publicity, such as when his team at Celera Genomics deciphered the human genetic code in a race with a government-sponsored Human Genome Project. His entry into oceanography, for which he has no training, has provoked both admiration and resentment.

Some oceanographers have said that Dr. Venter is not collecting enough ancillary data such as water temperature and salinity. They also said that some of the bacteria he found might have come from contamination of the sample, though the Science article said the researchers guarded against contamination.

And some critics say that a serious oceanographer would use a real research vessel, not a sailboat.

Dr. Venter conceded that one reason for using his own boat was that he could combine work with pleasure. He ended his press conference yesterday by saying: "I will be joining the vessel very soon to head to French Polynesia. It's tough duty."