metallireducens

Metallireducens is a genus of bacteria, specifically a group of Gram-negative, rod-shaped microorganisms that belong to the class Betaproteobacteria. They are obligate anaerobes, meaning that they thrive in environments with no oxygen.

Metallireducens bacteria are particularly known for their ability to reduce metals, such as iron and uranium, using organic compounds as electron acceptors. This process is an important mechanism for the degradation of organic matter in environments where traditional aerobic respiration is not possible.

Type species of the genus is Metalireducens erectus, often referred to as "ME", isolated from pumice-rich soil. ME has been found to grow on benzoate and other organic compounds, resulting in the reduction of U(VI) to U(IV). These reductions occur at the expense of the metabolic energy that would otherwise be used for growth in aerobic conditions.

Studies have shown that these bacteria can also contribute to the immobilization of toxic heavy metals in soil and groundwater by reducing these metals to highly insoluble forms. This can be particularly significant in the context of bioremediation, where microorganisms are used to clean up contaminated sites.

The growth and metabolic characteristics of Metallireducens species are studied in various fields, including geobiology, planetary science, and astrobiology, where understanding microbial adaptation to adverse environments is crucial for understanding, for example, potential microbial life forms that might exist on Earth's subsurface, or on other planets.

Fermentative metabolism of bacteria of this kind is a part of adapting to areas where oxygen cannot be present.