Wikipedia
Acidobacteria are a newly devised phylum of Bacteria, whose members are physiologically diverse and ubiquitous, especially in soils, but are under-represented in culture.
Members of this phylum are physiologically diverse, some being acidophilic, and were first recognized as a novel division in 1997. The first species, Acidobacterium capsulatum, of this phylum was discovered in 1991. 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.
As well as their natural soil habitat, unclassified group II Acidobacteria have also been identified as a contaminant of DNA extraction kit reagents, which may lead to their erroneous appearance in microbiota or metagenomic datasets.