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dc.contributor.advisorVoolstra, Christian R.
dc.contributor.authorRandle, Janna L.
dc.date.accessioned2019-03-25T08:44:53Z
dc.date.available2019-03-25T08:44:53Z
dc.date.issued2018-11
dc.identifier.doi10.25781/KAUST-FO933
dc.identifier.urihttp://hdl.handle.net/10754/631713
dc.description.abstractCoral bleaching, i.e. the loss of photosynthetic algal symbionts, caused by ocean warming is now the main factor driving reef decline, but not all corals are affected equally. Corals from the Arabian Seas have unusually high temperature tolerances, and recently studies implicated salinity as one of the contributing factors. In particular, a recent heat stress experiment at different salinities using the model system Aiptasia and Red Sea corals, showed that cnidaria at large bleach less at heat stress under high salinities and that this is associated with an increase of the osmolyte, floridoside Here we were interested to assess microbial community changes under heat stress at different salinity levels and whether this could help to explain the increase in thermal tolerance of the metaorganism at high salinities. We determined microbial community composition via HiSeq 16S rRNA gene amplicon sequencing of two anemone strains that differ in their associated symbionts, namely H2-SSB01 (type B1) and CC7-SSA01 (type A4), after six days under ambient (25 °C) and heat stress (34 °C) temperatures at salinities of 36, 39, and 42. Both anemones harbored distinct microbial communities, irrespective of temperature or salinity, that were also different from the bacteria in surrounding seawater. Within both host-endosymbiont pairings, the bacterial community composition at low (36) and intermediate (39) salinities did not differ between ambient and heat stress, but was significantly different at high (42) salinities. Subsequent elucidation of bacterial indicator species revealed several taxa that could be associated with a response to temperature and salinity. Our results underline that microbial community composition adjusts under different environmental settings. Importantly, microbial community dynamics of H2-SSB01 aligned with observed differences in bleaching susceptibility and thermal tolerance, whereas the pattern remains unclear for CC7-SSA01, which harbors an intrinsically higher thermal tolerance. Such responses could argue for a contribution of the microbiome to the observed increase in temperature tolerance of the Aiptasia metaorganism at increased salinities. An alternative interpretation is that the microbiome changes denotes a parallel response to changing salinities.
dc.language.isoen
dc.subjectbacterial community
dc.subjectheat stress
dc.subjectsalinity
dc.subjectcoral holobiont
dc.subjectthermaltolerance
dc.subjectAiptasia
dc.titleInsights into bacterial community changes following heat and salinity treatments in Aiptasia
dc.typeThesis
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Division
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberAranda, Manuel
dc.contributor.committeememberHirt, Heribert
thesis.degree.disciplineMarine Science
thesis.degree.nameMaster of Science
kaust.request.doiyes


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