October 05, 2007	Friday	Ramazan 22, 1428

CHICAGO, Oct 4: Scientists have uncovered thousands of marine microbes -- including never-before-seen bacteria -- thriving deep in the sea near cracks in the Earth’s crust where warm fluids and cold sea water mix, U.S. researchers said on Wednesday.

Using new DNA sequencing techniques, the researchers have identified as many as 37,000 different kinds of bacteria huddled near two hydrothermal vents on an underwater volcano off the Oregon coast.

“Many of these bacteria have never been reported before,”

said Julie Huber of the Marine Biological Laboratory in Woods Hole, Massachusetts, whose study appears in the journal Science.

Huber and colleagues at the University of Washington’s Joint Institute for the Study of Atmosphere and Ocean took samples from two hydrothermal vents on the Pacific deep-sea volcano, Axial Seamount.

“You’ve got hot fluids that have things in it like hydrogen gas and sulphur, which are not things you find in abundance in regular sea water. They’re mixing with this cold, oxygen-rich sea water.

“It creates a lot of neat niches for life,” Huber said in a telephone interview. Her research is part of an international effort to create a census of marine microbes, which make up as much as 90 per cent of the total ocean biomass by weight.

Huber and colleagues focused their study on a gene that is common to all microbes that is essential for protein synthesis.

“You have it. I have it. Even your dog has it. And microbes have it,” Huber said. Her team looked at 900,000 of these genes, a massive undertaking that allowed her to arrive at an estimate of the number of microbes in the sample.

They found the samples were dominated by epsilon Proteobacteria, which are found in many different places on Earth, including the human gut, and have been known to lurk around hydrothermal vents.

And while the two samples were taken just a few kilometres apart on the same volcano, they have totally different chemistries and population structures.

“We found they were completely different types of epsilon at the two different vents,” she said.

“We think it is because of the different geochemistries of the two different vents and the microbes have adapted to the two different environments.” Huber said her work will help serve as a baseline for understanding of the microbes currently in the ocean.

“A lot of people don’t realize that microbes make living on Earth possible. They produce the oxygen we breathe. They have been on this planet for 3.5 billion years,” she said.

“We really need to understand who is there and what they’re doing because things are changing, and they’re changing rapidly, and we don’t even know what the baseline is supposed to be”

And without that, she said, “We’re not going to know if things are changing.”—Reuters