Globally, citrus is threatened by huanglongbing (HLB), and the lack of effective control measures is a major concern of farmers, markets, and consumers. There is compelling evidence that plant health is a function of the activities of the plant's associated microbiome. Using
, a culturable surrogate for the unculturable HLB-associated bacterium “
Liberibacter asiaticus,” we tested the hypothesis that members of the citrus microbiome produce potential anti-“
. Liberibacter asiaticus” natural products with potential anti-“
. Liberibacter asiaticus” activity. A subset of isolates obtained from the microbiome inhibited
growth in an agar diffusion inhibition assay. Further fractionation experiments linked the inhibitory activity of the fungus
to the fungus-produced natural products cladosporols A, C, and D, demonstrating dose-dependent antagonism to
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
Chain elongation by medium-chain fatty acid (MCFA)-producing microbiomes offers an opportunity to produce valuable chemicals from organic streams that would otherwise be considered waste. However, the physiology and energetics of chain elongation are only beginning to be studied, and many of these organisms remain uncultured. We analyzed MCFA production by two uncultured organisms that were identified as the main MCFA producers in a microbial community enriched from an anaerobic digester; this characterization, which is based on meta-multi-omic analysis, complements the knowledge that has been acquired from pure-culture studies. The analysis revealed previously unreported features of the metabolism of MCFA-producing organisms.