Parasutterella

Parasutterella is a genus of Gram-negative, circular/rod-shaped, obligate anaerobic, non-spore forming bacteria from the Pseudomonadota phylum, Betaproteobacteria class and the family Sutterellaceae. Previously, this genus was considered "unculturable," meaning that it could not be characterized through conventional laboratory techniques, such as grow in culture due its unique requirements of anaerobic environment. The genus was initially discovered through 16S rRNA sequencing and bioinformatics analysis (a methodology to analyze the microbiome). By analyzing the sequence similarity, Parasutterella was determined to be related most closely to the genus Sutterella and previously classified in the family Alcaligenaceae.

In 2009, Parasutterella excrementihominis was cultured and characterized. In 2011, another species of Parasutterella, Parasutterella secunda, was discovered, and both Parasutterella and Sutterella species were reclassified under the family Sutterellaceae. (This reclassification occurred due to the similar biochemical potential in the Sutterella and Parasutterella genera different from other genera in the family Alcaligenaceae.) To date, Parasutterella contains two cultured species and numerous uncultured species. Both cultured species were isolated from human feces and are considered to be part of the gut microbiome in a healthy individual.