Abstract:Recent metagenomic surveys suggested that Epsilon-proteobacteria is abundant in deep-sea extreme environment such as hydrothermal vent and they play important role in carbon, nitrogen, hydrogen, and sulfur recycle in the ocean. A few studies have been carried out on this class of bacteria, mainly including 16S rRNA taxonomic identification and genomic sequence analysis from deep sequencing. This review summarized current understanding of ecological distribution and diversity of Epsilon-proteobacteria. Meanwhile, we elaborated diverse energy metabolism, powerful chemotaxis and motility, and relationships with benthic animals of Epsilon-proteobacteria. Meanwhile, we also discuss the adaptation mechanism of Epsilon-proteobacteria to deep-sea extreme environment to expedite our understanding and bioprospecting of the unique biological features of Epsilon-proteobacteria.