Microbial transformation of metals and metalloids.

Throughout evolution, microbes have developed the ability to live in nearly every environmental condition on earth. They can grow with or without oxygen or light. Microbes can dissolve or precipitate ores and are able to yield energy from the reduction/oxidation of metal ions. Their metabolism depends on the availability of metal ions in essential amounts and protects itself from toxic amounts of metals by detoxification processes. Metals are metabolised to metallorgano-compounds, bound to proteins or used as catalytic centres of enzymes in biological reactions. Microbes, as every other cell, have developed a whole range of mechanisms for the uptake and excretion of metals and their metabolised compounds. The diversity of microbial metabolism can be illustrated by the fact that certain microbes can be found living on arsenate, which is considered a highly toxic metal for most other forms of live.