酸杆菌门(Acidobacteria)是新近被分出的一门细菌。它们是嗜酸菌。现在对它们研究还很少，但它们在生态系统中具有重要作用，比如土壤中。

• 细菌分类表

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.