80 ■ CHAPTER 05 How Cells Work
CELLS
A
nnie Rowe stands knee-deep in cold,
clear salt water. Sweating, she pushes
a shovel into the ground and lifts a
mound of heavy mud. It’s a sunny day on Santa
Catalina Island, a rocky retreat off the coast
of California, where Rowe has come to collect
samples. Once the bucket is full, she sits on
a rock and retrieves a mesh filter to sieve out
any small invertebrates, such as snails and
worms, from the sand. They are not part of the
experiment.
A postdoctoral research fellow at the Univer -
sity of Southern California, Rowe pours the
filtered sediment into one of her five 10-gallon
aquariums. When each aquarium is about
two-thirds full, she and a graduate student
transport the tanks to a local laboratory on
the island. There, they hook each aquarium
up to a steady stream of seawater from the
harbor.
To t h e u nt r a i n e d e y e , t h e a q u a r iu m s a p p e a r
sterile, empty. In reality, both the water andsand in the tanks are teeming with micro-
scopic organisms, or microbes, and Rowe is
aiming to find a rare, strange one. Deep in the
sand of each aquarium, she buries a metal elec-
trode buzzing with electrical current to attract
her quarry: a microbe that eats electricity
(Figure 5.1).
“I went into microbiology because there’s
so much diversity in things that microbes can
do,” says Rowe. As a PhD student, Rowe began
studying unusual microbes with the hope of
someday putting them to use toward one of the
greatest human challenges of our time: develop-
ing sources of alternative energy.
Humans rely heavily on fossil fuels such as
oil and petroleum to power our cars, trains,
planes, and more. Hundreds of millions of years
ago, single-celled organisms used carbon diox-
ide and sunlight to make cell materials, which
then became buried and concentrated into
oil in Earth’s crust. Burning that oil releases
that ancient carbon dioxide back into theFigure 5.1
Annie Rowe burying electrodes in her sediment aquariums