Acidobacteriota is a phylum of Gram-negative bacteria. Its members are physiologically diverse and ubiquitous, especially in soils, but are under-represented in culture. Members of this phylum are physiologically diverse, and can be found in a variety of environments including soil, decomposing wood, hot springs, oceans, caves, and metal-contaminated soils. The members of this phylum are particularly abundant in soil habitats representing up to 52% of the total bacterial community. Environmental factors such as pH and nutrients have been seen to drive Acidobacteriota dynamics. Many Acidobacteriota are acidophilic, including the first described member of the phylum, Acidobacterium capsulatum. There is much that is unknown about Acidobacteria both in their form and function. Thus, this is a growing field of microbiology. Some of this uncertainty can be attributed to the difficulty with which these bacteria are grown in the laboratory. There has been recent success in propagation by using low concentrations of nutrients in combination with high amounts of CO2, yet, progress is still quite slow. These new methods have only allowed approximately 30% of subdivisions to have species documented. Additionally, many of the samples sequenced do not have taxonomic names as they have not yet been fully characterized. This area of study is a very current topic, and scientific understanding is expected to grow and change as new information comes to light. Other notable species are Holophaga foetida, Geothrix fermentans, Acanthopleuribacter pedis and Bryobacter aggregatus. Since they have only recently been discovered and the large majority have not been cultured, the ecology and metabolism of these bacteria is not well understood. However, these bacteria may be an important contributor to ecosystems, since they are particularly abundant within soils. Members of subdivisions 1, 4, and 6 are found to be particularly abundant in soils.
Melanie Blokesch, Frédérique Marie Jeanne Le Roux