Forces of Change

Microbes of Many Talents

Microbes make medicine. Soil microorganisms wage chemical warfare. Their bodies make compounds that kill other microbes—antibiotics! Soil bacteria make many of the familiar antibiotic medicines we take—penicillin, erythromycin, streptomycin, tetracycline, vanamycin.

Microbes make biofuel. Some lollipop-shaped soil bacteria make ethanol, a substitute for gasoline in flex-fuel cars and trucks.

Microbes make trouble. Bacillus anthracis—an uncommon but widespread bacterium—spends part of its life cycle in soils, where it survives for decades without growing. But when this bacterium gets into the nutrient-rich bodies of animals, it causes anthrax, a disease characterized by lesions and sometimes death.

Antibiotic mold, Penicillium notatum
Antibiotic mold, Penicillium notatum
What new wonder drugs lie hidden in the world of soil microbes? Today only one in one thousand soil bacteria have been screened for antibiotics.
© Dennis Kunkel Microscopy, Inc.
Biofuel microbe, Clostridium phytofermentans
Biofuel microbe, Clostridium phytofermentans
A microorganism that lives in a Massachusetts forest soil converts leaves and other plant detritus directly into ethanol. Scientists hope this versatile microorganism will make it possible to brew biofuel from grass clippings, wood chips and other natural plant fibers—a feat that is presently too complex to do economically.
Susan Leschine/University of Massachusetts
Anthrax, Bacillus anthracis
Anthrax, Bacillus anthracis
Anthrax was known to harm animals over 2000 years ago, long before humans tried to use it as a biological weapon.
© Dennis Kunkel Microscopy, Inc.