Seeing Life in a New Way
acid, the air quality, and the beastly tem-
and survival. The cave has relatively few
perature — are created by the action of
microbe species and relatively little con-
iron-eating microbial biofilms that line
tact with the outside world that might
The cave’s ecology provided a glimpse of
the cave. Denef spent six years as part of
introduce new microbes and their genes.
a complete kind of rainforest of unseen
a team exploring the northern California
Denef wanted to learn how biofilm popu-
creatures eating other creatures. We
cave’s tunnels for four or five hours at a
lations adapt to a shifting environment. Is
often think of the base of the food chain
time, clad head to toe in hot protective gear and dipping samples out of pools of greenish water matted with bright pink biofilms. “Ambient conditions are often close to the limit of human endurance,” he and a U-C Berkeley colleague wrote in a recent paper appearing in the journal Science. Though hostile to humans, the abandoned Richmond Mine in California provides an ideal model system for
Then, as the sun sets behind Alpena and the last of the dappled light fades from this submarine garden, one of the world’s most ancient battles begins in earnest. The white patches start to expand, spreading outward over the top of the purple skin. Within a few hours, the bottom will appear white with purple patches. And at dawn, when sunlight arrives, the battle will reverse.
studying how microbial communities survive, adapt, and swap useful genes in their never-ending struggle for primacy
In the cold depths of Lake Huron at the Middle Island Sinkhole, a location low in oxygen and high in sulfur, researcher Russ Green collects a microbial mat structure built by cyanobacteria. The tiny microbes comprise an ecosystem that may approximate the world’s earliest oceans and life forms.
Photo Joe Hoyt, NOAA
there a diversity of species with different
as these microbes, but really it’s elements
abilities lined up for succession, like in the
like iron and sulfur, the stuff the microbes
Lake Huron sinkhole, or do the microbes
eat. They make energy by breaking mol-
evolve in response to changing conditions?
ecules apart, starting the whole process
The answer turned out to be a bit of both.
in motion. “Once the biofilm builds this system up, other organisms can come in
Fall 2012 / LSA Magazine
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