The marine subsurface — a region that lies at least a meter below the seafloor — is equivalent in size to roughly 70 percent of the Earth’s surface and is thought to be home to a third of the world’s microorganisms. Because of their location, many of these species have not been studied, much less…

The most abundant freshwater bacterioplankton is one that researchers have been unable to grow for study in the lab, away from its natural habitat. The acI Actinobacteria make up as much as 50 percent of the plankton in freshwater lakes and rivers all over the world but researchers don’t know exactly what ecological role the…

Sulfur compounds can cause acid rain and corrode metal and concrete. Bacteria that can break down these compounds are known as sulfur-reducing bacteria (SRB). So far only one strain of some 25 Desulfotomaculum SRB species identified has been sequenced, so very little is known about these sulfur-reducing bacteria. Researchers know, for example, that the bacteria…

Chlorate contamination of groundwater is a big problem that is often associated with the manufacture and use of explosives and munitions. To clean up chlorate-contaminated areas, some researchers turn to bacteria that can break down these compounds. These microbes can produce oxygen in anaerobic conditions, which can speed up the process of breaking down other…

Bacteria that live in hydrothermal vents on land and deep underwater need to be able to tolerate high temperatures and harsh, nutrient-poor environments with high concentrations of metals. As a result of living in such environments, however, these bacteria have enzymes that are stable at high temperatures, which could be useful for producing alternative fuels….

Though nitrogen is an abundant element in the Earth’s atmosphere, plants can’t use it unless it’s been converted into another form. An estimated 80 percent of the nitrogen “fixed” through biological means comes from the symbiosis between bacteria in the root nodules and legume plants such as lentils and peanuts. This relationship is thought to…

The genus Desulfurococcus represents a unique clade (a group of organisms all descended from a common ancestor) in the domain of archaea that is not currently represented in the publicly available genomic databases. This scenario will change to some extent as Desulfurococcus mucosus genome sequence is determined under the GEBA (Genomic Encyclopedia for Bacteria and…

When researchers want to understand how microbes interact with toxic materials, they often sequence the organisms collected at waste sites. Bacteria such as Dehalococcoides and Dehalogenimonas lykanthrorepellens are found in soil and groundwater contaminated with chlorinated compounds such as the dry-cleaning agent tetrachloroethene and the industrial solvent trichloroethene. Cleaning up these contaminated sites can cost…

Scientists classify organisms under one of three categories: eukaryotes, which include plants, animals and fungi, bacteria and archaea. Some researchers think archaea may be descended from some of the earlier life forms on the plant, and that they haven’t changed very much over time. By studying them, researchers hope to learn more about the origins…

Bioremediation uses microbes to break down organic contaminants in polluted soil or water in order to restore or protect natural resources. One example involves using microbes to remove the chlorinated contaminants in the groundwater. The process can take a while, depending on factors such as the size of the polluted area, the amount of chemicals…