New Study Shows Group Of Marine Bacteria Dominate Offshore Waters Of Southeast, May Play Key Role In Ecosystem...( lture in laboratories. And eventhe o...)

That has all changed in the past few years with the advent of new techniques to identify bacteria at the level of their basic building blocks. Using specific gene sequences as targets for identification, scientists can recognize and identify bacteria without the need to culture them first.

"The target for our work is called the 16S ribosomal RNA gene," said Moran, "and it's a good gene to focus on because all living things need ribosomes to make proteins."

It's all about what happens inside the cell. Ribosomes are small cellular components where protein synthesis takes place, and they are composed of specialized ribosomal RNA (which is abbreviated rRNA) molecules. The genes coding for rRNA are an essential component of the genetic material of all prokaryotes (cellular organisms such as bacteria that lack a limiting membrane), but they vary enough to give each species a unique name tag.

Moran and Gonzlez found preliminary evidence that a cluster of marine bacteria may be particularly important in coastal seawater of the southeastern U. S. and then used the key rRna gene to quantify just how abundant they may be. In work that is drawing considerable interest from marine scientists worldwide, they designed a "probe," a molecule that is labeled in some way - usually with radioactivity or fluorescence - to seek out the 16S rRNA gene of marine alpha bacteria in seawater. The probe looks for similar sequences of base pairs (the chemical building blocks of the double-stranded DNA) and marks them by hybridizing to them.

Using this process, the marine scientists were able to discover, to their surprise, that up to 30 percent of the bacterial genes present at a num
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Contact: Phil Williams
Philwpio@uga.cc.uga.edu
706/542-8501
University of Georgia
24-Apr-1998