Which organism is not known as an iron bacterium?

The organism known as Giardia lamblia is not classified as an iron bacterium. Giardia lamblia is a protozoan parasite that causes giardiasis, an intestinal infection. It thrives in contaminated water, primarily affecting the digestive system of humans and animals. While it can produce various symptoms and health issues, it does not play a role in the oxidation of iron or the formation of iron-related deposits, which are characteristics of iron bacteria.

In contrast, Crenothrix, Gallionella, and Leptothrix are all known as iron bacteria. These organisms derive energy from the oxidation of ferrous iron (iron in a +2 oxidation state) to ferric iron (iron in a +3 oxidation state) and are often found in iron-rich waters. They contribute to the formation of iron oxide deposits, which can be observed in certain aquatic environments and can affect infrastructure, such as pipes and water systems, leading to issues like staining and clogging.