Participant Perspective - July 21, 2001

Interview with Mausmi Mehta
Microbiologist, U. Washington

Jeff: Why are you so interested in the microbiology of hydrothermal vents?

Mausmi: As an undergraduate I was strictly learning microbiology. While it was interesting, I thought it would be more exciting to apply it to a field that was related, but not exactly what I had studied previously. It's fascinating. I read all about it when I was younger and watched the discovery channel and PBS programs on the hydrothermal vents. I thought it would be amazing to get to do both what I had been trained to do and this whole new thing with oceanography which I hadn't done before.

Jeff: What are you studying at Axial Volcano?

Mausmi: I'm looking at diffuse fluids, and in particular, for nitrogen-fixing organisms. These are microorganisms (bacteria and archaea) that can use
nitrogen in the form of a gas (N2) dissolved in seawater. The reason that this is so important is that there are low levels of nitrogen down there and it's
possible that whole communities are limited by nitrogen. If these microorganisms are able to fix nitrogen, they would be able to alleviate the nitrogen limitation by fixing it for the rest of the community. To look for these nitrogen-fixing microorganisms I'm looking for an ancient gene that only the nitrogen-fixers have. The fixing process, therefore, is ancient and has been speculated to have arisen pretty early in the evolution of the planet.

Jeff: Are hydrothermal vents a possible place for life to have begun on our planet?

Mausmi: Possibly, yeah. If anywhere, I'm most likely to believe that hydrothermal vents are the place where life originated on earth.

Jeff: Do archaea or bacteria dominate below the seafloor?

Mausmi: It depends on temperature and habitat which ones dominate below the seafloor. It's still something that hasn't been worked out yet because it's hard to get numbers on it. We sample the fluids coming out of the sub-seafloor
with the hot fluid sampler to give us an idea what's below.

Jeff: What's all the excitement about hyperthermophiles (microorganisms that live in extremely hot environments)?

Mausmi: Both archaea and bacteria have hyperthermic members. It's so different from what we're used to. Part of the excitement applies to industrial applications for organisms that can carry out enzymatic processes at such high temperatures. The biotechnology industry is very interested.