Page 2 - 2008 DT 12 issues

Mighty Microbes considerably greater biodiversity. forms were first discovered in Yellow-
The enzymes excreted by repro- stone’s hot springs, a laboratory for
icrobes—those nasty little ducing bacteria naturally clean up the exploration of the microbial world.
bugs that inhabit our envi- environmental pollution caused by They provide a vivid example of what
Mronment, bringing disease oil spills and industrial waste, break- a gang of bacteria can look like when
and creating havoc. All kinds of mis- ing down their organic carbons over they get together. Each hot spring
eries are inflicted upon us, courtesy a period of time. Bio-remediation is unique, supporting different mi-
of microbes, from food poisoning to companies add various compounds to crobes depending upon the chemical
deadly viruses. On the other hand, we help the pollutants degrade more quickly, environment. The vivid reds, yellows,
might not even be here if it weren’t for or introduce microbes that have been col- greens and blues of the many thermal
lected from another site and commer-
these tiniest of life forms. Perhaps we pools are produced by specialized mi-
should take a closer look before we crobes that form microbial mats.
rush to judgement. Their colors depend upon the interac-
What are microbes, exactly? tion of green chlorophyll, and red and
Don’t consult your dictionary, be- orange carotenoids which protect the
cause it, too, has a closed mind: “A mats from sunlight.
minute life form; a microorganism, These “extremeophiles” can
especially a bacterium that causes live and reproduce in highly acid-
disease.” Small wonder the word ic, salty or alkaline environments,
microbe engenders such fear and usually at scalding temperatures.
loathing. Yet most are harmless, They are derived from Archaea,
and many diverse microbes benefit the most ancient of the three do-
the earth and its inhabitants in a mains of life on earth. Most
multitude of ways. Archaea live in extreme environ-
It is estimated that 70% of the The Three Buddhas ments, but many do not. Some
total biomass of earth consists of even inhabit the digestive tracks of
microbes. Every good gardener knows cially cultivated, to speed the process humans and other mammals.
the value of a compost pile. The bacte- even further. A new bacterium that can con-
ria and fungi that break down its organic Our tiny life forms inhabit every vert light into energy was recently
matter and turn it into fertilizer, increase nook and cranny on earth and every liv- discovered in three of Yellowstone’s
the availability of soil minerals, such ing thing—specialists adapting to any hot springs. According to David M.
as nitrogen and phosphorous. Mi- environment, from the coldest to the Ward, a professor of microbial studies
crobes create a diversity of life in the hottest, deepest, most remote and most at Montana State University, “It has
soil, helping plants resist pathogens. hostile places on the planet. Rock-eat- a new kind of photosynthesis. It uses
And, what about that soil? Without rock- ing bacteria have been found two miles the same kind of machinery [as other
eating bacteria, there wouldn’t be much or more below the ocean floor, living bacteria], but has the parts in a dif-
soil on the planet, either. without the benefit of light, oxygen or ferent arrangement.”
A study conducted by the Univer- carbon dioxide. Sea floor sediments At the “Three Buddhas” hot
sity of Colorado at Boulder and Duke harbor diverse microbial life, much of it springs in Garlach, Nev., researchers
University in Durham, N.C., collected in unknown forms. Microbes utilize the from Harvard and the University of
soil samples from 98 sites throughout energy released by geological processes, Georgia discovered that the microbial
North and South America and made an too. Blistering hot sea-floor vents are group, Crenarchaeota, inhabitants of
interesting discovery. The only factor teeming with heat-loving bacteria, fil- the 104-degree waters of the Buddhas,
that seemed to affect microbial bio- tering nutrients and minerals from evolved 3.5 billion years ago, shortly af-
diversity in any location was soil pH. the chemical brew rising through the ter life forms began to emerge on earth.
Acidic soils, such as those in the Ama- vents. In the deep ocean, microbes trans- Closer to home, bacteria drive the
zonian rainforest, tended to harbor fewer form the rocks, assisting in the chemical processes of fermentation that trans-
species. Soils closer to neutral pH, like reactions that regulate ocean chemistry. form foods, such as yogurts, bread,
those in the Arizona desert, showed Some of the most ancient of life beer, wine and some cheeses, vegeta-
Page 2 FORRC/January/2008