Meet Deinococcus radiodurans, one of the world’s toughest bacterium. It’s an extremophile and one of the most radiation-resistant organisms known on Earth. This hardy little bacterium can survive over a thousand times the amount of radiation that would kill a human. Its tolerance to many harsh conditions has earned itself the name “Conan the Bacterium,” after the movie Conan the Barbarian. D. radiodurans is a spherical bacterium and four individual cells are typically stuck together forming a square shaped cluster. Aside from radiation resistance, D. radiodurans is also resistant to ultraviolet light and desiccation. (more…)
When it comes to predators, we naturally think of large, agile, and powerful animals on the prowl. But we often don’t think about the most abundant predators on our planet, predators of the microscopic world. In the depths of the microbial universe, predatory bacteria (those that feast upon other bacteria) have emerged. These bacteria are now ubiquitous in terrestrial and marine environments. Predatory bacteria penetrate the outer membrane of bacterial prey and ingest their prized nutrients, killing the prey. (more…)
Anyone who has dabbled into molecular biology knows that Escherichia coli has been the go-to model organism for quite some time. As an organism that is easy to grow and easy to genetically manipulate in the lab, E. coli has become one of the most commonly used microorganisms in labs that study a variety of biological systems. It has been used to inform the behavior of other bacteria (which may be harder to grow or more difficult to work with). Outside of strictly microbiology research, E. coli has been used to produce many biomolecules by inserting genes needed to produce these molecules into the bacterium. (more…)
"Life has evolved to thrive in environments that are extreme only by our limited human standards: in the boiling battery acid of Yellowstone hot springs, in the cracks of permanent ice sheets, in the cooling waters of nuclear reactors, miles beneath the Earth's crust, in pure salt crystals, and inside the rocks of the dry valleys of Antarctica." -Jill Tarter, astronomer
Yellowstone National Park (YNP) is well known for its geothermal features and diverse ecosystems. With features such as hot spring, geysers, canyons and forests, it's no wonder that the biodiversity (microbial and not) at YNP is enormous. (more…)
The first Microbe of the Month is Helicobacter pylori, my favorite bacterium during my graduate school years.
Discovery of Helicobacter pylori
Stomach ulcers were traditionally thought to be caused by stress. However, in 1982 Barry Marshall and Robin Warren discovered that the bacterium Helicobacter pylori (H. pylori for short) is actually the cause of these ulcers. These scientists found that almost all stomach biopsies from patients with gastric ulcers also contained this helical shaped bacteria (hence the name Helicobacter). Barry and Marshall's discovery was met with much skepticism at the time. Desperate to prove that H. pylori was indeed the cause of gastric ulcers, Marshall drank a culture of H. pylori and developed gastric ulcers that were accompanied by H. pylori in his gastric biopsies. He then cured himself of the infection by taking antibiotics. For this discovery Marshall and Warren were awarded the Novel Prize in Physiology or Medicine in 2005. (more…)