Press Release

Genomic tools reveal new microbial phototrophs in the ocean

By SpaceRef Editor
February 17, 2002
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MOSS LANDING, California Genomic technologies are now
being taken to sea, and are helping researchers discover the identity and
more importantly the ecological roles, of microbes in the ocean. In a
new study published this week in Nature, MBARI microbiologists
describe new and diverse groups of photosynthetic bacteria found in
oceanic plankton.

"It’s an exciting time for microbial oceanography genomics-based
discoveries are changing fundamental paradigms about what kinds of
microbes live in marine plankton and how they convert energy from the sun
into nourishment for the rest of the oceanic food web," said Ed
DeLong, leader of the research group. The genomic ‘libraries’ of
oceanic microbes we study are providing us with a kind of genetic
encyclopedia. We can ‘look up’ the identity, properties, and functions
of naturally occurring microbes in that encyclopedia. Every time we do, it
seems, we find something new."

In this recent Nature study, MBARI researchers,
in collaboration with colleagues from The Institute for Genomic Research,
analyzed the genomes of microbes found in Monterey Bay and the central
Pacific Ocean. They found that a wide variety of bacterial photosynthetic
genes, previously not thought to be significant in marine plankton, are
actually widely distributed in ocean waters. The work also showed that the
bacterial photosynthetic genes were expressed in oceanic plankton,
indicating that these microbes were actively garnering energy from light.

Why is this important? Chlorophyll containing
"plant plankton," or phytoplankton, have long been thought to be
the main photosynthetic groups in the ocean. The current MBARI study
identifies ecologically significant groups of photosynthetic plankton that
don’t contain the chlorophyll found in green plants. The existence of
these new types of phototrophs (organisms that get energy directly from
light) has stimulated oceanographers to re-think and revise oceanic food
web models. Quantifying the impact of such microbes in the food web may
help oceanographers balance the global carbon budget sheet.

"Microbial diversity and function in natural
environments is not all that well understood. With new tools to compliment
more traditional approaches, we can begin to get a more realistic picture
of real-world complexity," said DeLong. "Genomic technology is
opening up a whole new and previously unseen world."

Media contact:
Debbie Meyer,
or 831-775-1807.

Research article:

Béj, O., M.T. Suzuki, J.F. Heidelberg, W.C. Nelson, C.M. Preston,
T. Hamada, J.A. Eisen, C.M. Fraser, and E.F. DeLong (2002). Unsuspected
diversity among marine aerobic anoxygenic phototrophs. Nature±J2Fi>, 415: 630-633.

SpaceRef staff editor.