Ancient Bacteria...

Two microbiologists have resuscitated a microorganism which had been suspended in an insect embalmed in amber. The scientists have found approx. 1,000 species of bacteria which remained in suspended animation for 25 to 40 million years. Studying ancient bacteria may help scientists understand DNA mutation.

Bacillus is an ancient genus of bacteria that is known to form endospores. The spores are protected from the effects of heat, radiation, pressure and environmental contamination by a thick, protective protein coat. Bacteria can remain in this dehydrated cryptobiotic state for millions of years, said Dr. Raul Cano, a microbiologist at Cal Poly.

Raul J. Cano claims he resurrected at least 30 to 40 species of bacteria from ancient spores, and grew them on culture plates. Now he's analyzing those bacteria. Most, he says, are members of the genus Bacillus, an ancient, spore-forming group of bacteria that is widely distributed today. Some members of the genus (Bacillus thuringiensis) are used for biological control of insects.

Raul J. Cano and Monica K. Borucki discovered the bacteria preserved within the abdomens of insects encased in pieces of amber. In the last 4 years, they have revived more than 1,000 types of bacteria and microorganisms -- some dating back as far as 135 million years ago, during the age of the dinosaurs.

In the May 19 Science, the two, from California Polytechnic State University in San Luis Obispo, describe resuscitating a species of bacteria from a sample of amber 25 million to 40 million years old.

Cano and Borucki revived the spores in a nutrient solution and grew colonies of bacteria, which they identified as Bacillus sphaericus, a species that exists symbiotically in some bees.

Cano believes the spores survived because the amber kept them dry. Recent work has demonstrated amber's remarkable preserving power. In 1993, Cano reported finding the oldest known DNA from insects in amber.

In October 2000, another research group used many of the techniques developed by Cano’s lab to revive 250-million-year-old bacteria from spores trapped in salt crystals. With this additional evidence, it now seems that the "impossible" is true.

Hundreds of millions of years ago, before dinosaurs roamed the planet, an ocean rippled where the sun now bakes a New Mexico desert. As that seawater evaporated, its salt crystallized, sometimes trapping pockets of brine.

Covered by sediments over the years, those salt deposits currently sit half a mile below the desert floor. Microbiologists who have procured samples of the salt crystals and carefully tapped into the pockets, called inclusions, now claim to have isolated and revived bacteria that were last active 250 million years ago.

If the salt-derived microbes are hundreds of millions of years old, comparing their DNA with that of modern organisms should prove illuminating. "You can actually look at evolution on a molecular basis and do molecular paleontology."

Are there papers from refereed journals on this subject that are recent - like in the past 4 years?