Bacteria Revived After 25 Million Years!
SAN LUIS OBISPO- In what may be the ultimate Rip Van Winkle
experiment, researchers claim to have revived bacterial spores
found in the belly of a bee frozen in amber some 25 million years
Researchers at the California Polytechnic State University
cracked open a piece of Dominican amber and extracted material
from the abdomen of a bee encased therein. The amber is dated at
25 and 40 million years based on the microscopic fossils found in
the geographic strata in which the amber was found.
The extracted material was placed in Petri dishes containing
a nutrient solution (trypticase soy broth). Within two weeks,
bacteria subsequently identified as Bacillus sphericus grew in
the culture. A comparison of the DNA of ancient and modern
bacteria appeared to confirm that the bacteria had indeed grown
from the ancient spores. Morphological, enzymatic and
biochemical identification methods were used to make a specific
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.
What was the bacteria doing in the bee's stomach? Bacillus
species form symbiotic relationships with numerous bee species.
While the bees provide a home for the bacteria, the bacteria aid
metabolic processes within the bees. When facing starvation, the
bacteria undergo transformation to spore form, he explained.
Critics were quick to claim that the bacteria was not
ancient at all, but represented some form of modern-day
contamination of the sample. Dr. Cano anticipated these
objections and included a number of safeguards in his
experiments. First of all, rigorous decontamination procedures
were used to sterilize the surface of the amber before it was
cracked. Second, the entire procedure was conducted under a
decontaminated, class II laminar flow hood that had never been
used for any other bacterial extraction processes.
The researchers also instituted a number of control
measures during the procedure to monitor for external
contamination. For example, pieces of the broken amber were
incubated with the solutions used in the sterilization process
for two weeks, with no evidence of bacteria. Petri dishes
containing soy agar were also placed under the hood throughout
the tissue removal process. These control dishes were incubated
for two weeks with no evidence of bacterial contamination.
"We have discovered a brand new source of organisms that
could produce life-saving pharmaceuticals or be used in valuable
industrial processes. There is almost no downside. These bacteria
are different enough to give us new substances, but not different
enough that we can't recognize them. There's no more danger with
these bacteria than there is with any newly discovered modern
microorganisms," he said.
Cano actually first succeeded in reviving the bacteria in
1991 but waited to publish in order to repeat and validate the
initial results. In 1992, Cano announced the extraction and
cloning of insect DNA from the Jurassic period, coinciding
with the opening of the film "Jurassic Park". Since that time he
and colleagues have isolated bacteria as old as 135 million
However, the current research does not mean scientists are
one step closer to reviving dinosaurs, he noted: "It has been
known for some time that because of their size, structure and
composition, some bacteria can survive as spores for long
periods, much as seeds outlive a plant. That is not true of more
Dr. Cano is now working with a company to try and develop
useful diagnostic and therapeutic applications for ancient
bacteria. The discovery of such ancient organisms could also
yield significant new information on the evolution of bacteria.
For more information on this study please refer to: Science,
v.268, 5/19/95, pp 1060-1064. Cano et al.
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