The class Zetaproteobacteria is the sixth and most recently described class of the Pseudomonadota. Zetaproteobacteria can also refer to the group of organisms assigned to this class. The Zetaproteobacteria were originally represented by a single described species, Mariprofundus ferrooxydans, which is an iron-oxidizing neutrophilic chemolithoautotroph originally isolated from Kamaʻehuakanaloa Seamount in 1996 (post-eruption). Molecular cloning techniques focusing on the small subunit ribosomal RNA gene have also been used to identify a more diverse majority of the Zetaproteobacteria that have as yet been unculturable.
Microbial mats encrusted with iron oxide on the flank of Kamaʻehuakanaloa Seamount, Hawaii. Microbial communities in this type of habitat can harbor microbial communities dominated by the iron-oxidizing Zetaproteobacteria.
Mariprofundus ferrooxydans PV-1 twisted stalks TEM image. One example of Fe oxide morphotypes produced by the Zetaproteobacteria. Image by Clara Chan
Mariprofundus ferrooxydans PV-1 cell attached to twisted stalk TEM image. Image by Clara Chan.
Pseudomonadota is a major phylum of Gram-negative bacteria. Currently, they are considered the predominant phylum within the realm of bacteria. They are naturally found as pathogenic and free-living (non-parasitic) genera. The phylum comprises six classes Acidithiobacilia, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Hydrogenophilia, and Zetaproteobacteria. The Pseudomonadota are widely diverse, with differences in morphology, metabolic processes, relevance to humans, and ecological influence.
Pseudomonadota
