How Does a 500-Year Experiment Work?

Bacteria can survive way longer than humans under the right conditions, so a team of researchers designed an experiment on microbes that will take 500 years to complete. Learn more in this episode of BrainStuff.

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Episode Transcript

Speaker 1 (00:02):
Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff,
Lauren Vogelbaum here. Some types of bacteria are known for
their ability to survive extreme conditions, from high temperatures to
chemical attacks to dehydration, but for how long are they
really viable? In A team of scientists dried a collection
of bacteria, sealed those specimens away in small glass vials,

(00:25):
and in five hundred years, some researcher will have the
honor of bringing the long lived study to a close.
The five century long experiment was conceived by researchers at
Scotland's University of Edinburgh, who teamed up with German and
American scientists in hopes of advancing human kinds understanding of
bacteria longevity. A major catch, none of them, or their

(00:45):
children or great great grandchildren are likely to be around
to see the results. In an email interview, Charles Cockle,
one of these scientists involved with the project, said the
motivation for the experiment was straightforward quote. Most science experiments
were on grant or human lifespans, but nature works over
long time periods. We wanted to create an experiment that

(01:05):
was more aligned to the length of time of interest
for studying microbes. For the experiment, team members filled eight
hundred vials with one of two types of bacteria, Crococca
diiopsis or Baccillus subtalis. The former is a true survivor,
a very primitive bacterium often found in extremely inhospitable environments
from hot springs to deserts. The latter is one of

(01:27):
the most studied bacterium in all of science, one that
can revert to a dormant state, surrounding itself with a
spore and basically going into hibernation when it's subjected to
environmental changes. The glass files the scientists filled were completely
sealed off from air, and half of them were shrouded
and lead to thwart the possible effects of radiation or
other potential interferences that could cause DNA damage. For the

(01:49):
first quarter century, scientists will check on the bacteria every
other year to see if they're still viable. Then the
check up schedule will shift to once every twenty five
years until the five hundred year test is over. The
actual tests are easy, simply requiring a basic rehydration process
and counting the bacteria colonies. But what's the best way
to describe the experiment to people four hundred years into

(02:10):
the future. Instructions were printed on paper and also stored
to a flash drive, with the explicit request that researchers
update the verbiage and technologies when they perform their twenty
five year checks. The first analyzes were conducted in with
results published in December the GIST. After two years of isolation,
bacteria spores demonstrated hardly any decrease in viability. Some of

(02:34):
the surviving spores were then purposefully exposed too tougher conditions
like high salt levels or a spacelike vacuum. These specimens
then showed an increased loss of viability. But what's the
best case scenario of such a long term project, the
Cockle said, there isn't an ideal outcome as such. We
want to learn how quickly microbes die and what mathematical

(02:55):
function describes their death over century time scales. Some by
tiria are so durable that they can remain viable for
tens of millions of years, provided they're preserved in one
form or another. For example, scientists have revived bacteria immersed
in twenty five million year old tree sap and also
from the carcasses of creatures like beetles that were trapped

(03:15):
in amber a hundred and thirty five million years ago.
Other researchers found that bacteria in New Mexico salt deposits
were still viable after two hundred and fifty million years.
Today's episode was written by Nathan Chandler and produced by
Tyler Clay for iHeart Media and How Stuff Works. For
more on this and lots of other topics with the

(03:35):
future in mind, visit our home planet, how stuff Works
dot com.