represents the dominant faunal biomass at many deep-sea hydrothermal vent ecosystems along the Mid-Atlantic Ridge. This organism harbors dense bacterial epibiont communities in its enlarged cephalothoracic chamber that play an important nutritional role.
are ubiquitous in epibiotic communities of
, and their functional roles as epibionts are based solely on the presence of functional genes. Here, we describe “
Desulfobulbus rimicarensis,” an uncultivated deltaproteobacterial epibiont. Compared to campylobacterial and gammaproteobacterial epibionts of
, this bacterium possessed unique metabolic pathways, such as the Wood-Ljungdahl pathway, as well as sulfur disproportionation and nitrogen fixation pathways. Furthermore, this epibiont can be distinguished from closely related free-living
strains by its reduced genetic content and potential loss of functions, suggesting unique adaptations to the shrimp host. This study is a genomic and transcriptomic analysis of a deltaproteobacterial epibiont and largely expands the understanding of its metabolism and adaptation to the