Changes in the microbiome of the sea anemone Exaiptasia diaphana during bleaching from short-term thermal elevation

We examined the response of microbial communities in model sea anemone Exaiptasia diaphana (Aiptasia) to short-term thermal elevation. Through 16S rRNA gene sequencing, we characterized microbiomes symbiotic (with algal symbionts) and aposymbiotic (bleached) anemones under ambient (27°C) heat-stressed (34°C) conditions for 8-10 days, using both replicated endpoint non-replicated time-course approaches. Consistent with prior studies, observed a stable abundance bacteria from families Alteromonadaceae Rhodobacteraceae, though wide variation among individual anemones. that state conferred larger impact on microbiome than heat stress, implying may play metabolic role maintenance cnidarian-dinoflagellate symbiosis. In particular, Pelobacter , an anaerobic sulfate reducer is also potential nitrogen fixer, was present only anemones, its decreased initial exposure 34°C, but recovered after 7 days. added stress appeared result large increase rare bacterial taxa, which included pathogens such as Vibrio following bleaching. several archaea, first reported this model, seawater surrounding Aiptasia, where increased dramatically stress. further explored diazotrophic (nitrogen fixation) diverse associated conditions, nifH -PCR qPCR acetylene reduction assay (ARA). contrast some stony corals, barely expressed types, activity not detectable via ARA. Thus, although research contributes growing knowledge community prominent used coral-symbiosis research, our results suggest caution when making direct comparisons between Aiptasia different coral species studies.