ABSTRACT

Microbial communities associated with sponges play important roles in sponge health, defence and nutrient dynamics in coral reef systems. Here, we used a 16S rRNA gene high-throughput sequencing approach in order to test for differences in bacterial composition and predictive functional differences among two LMA (low microbial abundance) (Stylissa carteri and Stylissa massa), one well-known HMA (high microbial abundance) (Xestospongia testudinaria), one putative HMA (Aaptos lobata) sponge species, sediment and seawater in a coral reef ecosystem surrounding Tioman Island. Our results showed that biotope (sponge species, sediment and seawater) was a significant predictor of composition and abundance of bacterial communities. Proteobacteria was the dominant phylum in S. carteri, seawater, sediment and A. lobata, whilst bacterial communities of S. massa and X. testudinaria were dominated by Cyanobacteria and Chloroflexi, respectively. The predicted metagenome revealed differentially enriched pathways in HMA and LMA sponges. Differentially enriched subcategories in HMA sponges included ‘Signaling Molecules and Interaction’, ‘Carbohydrate Metabolism’ and ‘Excretory System’. Subcategories enriched in LMA sponges included ‘Replication and Repair’, ‘Energy Metabolism’, ‘Metabolism of Cofactors and Vitamins’ and ‘Environmental Adaptation’. Overall, the predicted functional analysis suggests that, although HMA and LMA associated bacterial communities shared core functional features, they use different strategies to defend against pathogens, obtain energy or cope with stress.

摘要

与海绵有关的微生物群落在珊瑚礁系统中的海绵健康，防御和营养动态方面发挥着重要作用。在这里，我们使用16S rRNA基因高通量测序方法来测试两种LMA（低微生物丰度）（Stylissa carteri和Stylissa massa）之间的细菌组成差异和预测功能差异，一种著名的HMA（高微生物含量）丰度）（Xestospongia testudinaria），一种推定的HMA（Aaptos lobata）刁曼岛周围的珊瑚礁生态系统中的海绵物种，沉积物和海水。我们的结果表明，生物群落（海绵种类，沉积物和海水）是细菌群落组成和丰度的重要预测指标。变形杆菌是占主导地位的门S. carteri，海水，沉积物和A.野葛，而细菌群落S.马萨和X. testudinaria蓝细菌和绿弯曲菌分别占主导地位。预测的基因组揭示了HMA和LMA海绵中差异丰富的途径。HMA海绵中差异丰富的子类别包括“信号分子与相互作用”，“碳水化合物代谢”和“排泄系统”。富含LMA海绵的子类别包括“复制和修复”，“能量代谢”，“辅因子和维生素的代谢”和“环境适应性”。总体而言，预测的功能分析表明，尽管HMA和LMA相关的细菌群落具有共同的核心功能特征，但它们使用不同的策略来防御病原体，获取能量或应对压力。