Data_Sheet_1_Short-Term Exposure to Sterile Seawater Reduces Bacterial Community Diversity in the Sea Anemone, Exaiptasia diaphana.docx

The global decline of coral reefs heightens the need to understand how corals may persist under changing environmental conditions. Restructuring of the coral-associated bacterial community, either through natural or assisted strategies, has been suggested as a means of adaptation to climate change. A low complexity microbial system would facilitate testing the efficacy of microbial restructuring strategies. We used the model organism for corals, Exaiptasia diaphana, and determined that short-term (3 weeks) exposure to filter-sterilized seawater conditions alone reduced the complexity of the microbiome. Metabarcoding of the V5–V6 region of the bacterial 16S rRNA gene revealed that alpha diversity was approximately halved in anemones reared in filter-sterilized seawater compared to controls reared in unfiltered seawater and that the composition (beta diversity) differed significantly between the two. By reducing the complexity of the E. diaphana microbiome, the development of a system for testing assisted strategies such as probiotics, is more feasible.全球珊瑚礁的衰退加剧了学界对阐明珊瑚如何在变化环境条件下存续的迫切需求。通过自然或辅助策略重塑珊瑚相关细菌群落，被视为助力珊瑚适应气候变化的可行途径之一。低复杂度微生物系统可简化微生物重塑策略的效力测试流程。我们选取珊瑚研究的模式生物——透明海葵（Exaiptasia diaphana）开展实验，发现仅将其置于过滤灭菌海水环境中短期（3周）暴露，即可降低其微生物组的复杂度。对细菌16S rRNA基因V5-V6可变区的元条形码测序（metabarcoding）结果显示：与未过滤海水饲养的对照组海葵相比，过滤灭菌海水中饲养的海葵的α多样性约下降50%，且二者的群落组成（β多样性）存在显著差异。通过降低透明海葵微生物组的复杂度，开发用于测试益生菌等辅助策略的实验系统将更具可行性。