Microbial Ecology and Evolution Research Group, Centre of Marine Sciences (CCMar), University of Algarve (UAlg), Gambelas, 8005-139, Faro, Portugal.
Mol Ecol. 2014 Jun;23(12):3097-112. doi: 10.1111/mec.12789. Epub 2014 Jun 9.
In spite of their putative relevance to host functioning, in-depth knowledge of sponge microbiome stability over time is scarce. This study tackles the temporal maintenance of bacterial and archaeal assemblages in the model host Sarcotragus spinosulus along three successive years. Prokaryotic communities were profiled by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and 454-pyrosequencing of S. spinosulus-derived 16S rRNA gene amplicons. Prevailing bacterial phyla were Actinobacteria, Acidobacteria, Proteobacteria, Poribacteria, PAUC34f, Chloroflexi and Bacteroidetes, with Bacteroidetes, Chloroflexi and Poribacteria showing different abundances over the years. At the approximate species level (operational taxonomic units, OTUs, defined at 97% sequence similarity), no major changes in bacterial richness and composition were found through time. Nearly 50% of all detected bacterial symbionts (96 in 205 OTUs) were recovered from all sampling years, whereas a taxonomically equivalent community of less dominant bacteria characterized the transient sponge microbiota. Despite the evidence for temporal symbiont maintenance, an intriguing cumulative degree of variation between individuals was unravelled, with all the surveyed sponge specimens sharing only 27 bacterial OTUs. Archaeal communities were dominated by one single symbiont of the candidate genus Nitrosopumilus (Thaumarchaeota), known for its ability to aerobically oxidize ammonia to nitrite. Only few bacterial ammonia oxidizers consistently occurred in S. spinosulus across the years as documented by PCR-DGGE fingerprinting. In conclusion, prokaryotic symbionts of S. spinosulus display a state of dynamic stability shaped by the interplay between the maintenance of dominant players and turnover of less prevalent community members, in time and across host individuals, with no apparent consequences to holobiont functioning.
尽管它们与宿主功能有关，但关于海绵微生物组随时间的稳定性的深入知识却很少。本研究在连续三年的时间里，研究了模型宿主 Sarcotragus spinosulus 中细菌和古菌组合的时间维持情况。通过聚合酶链反应-变性梯度凝胶电泳（PCR-DGGE）和基于 S. spinosulus 衍生的 16S rRNA 基因扩增子的 454 焦磷酸测序，对原核生物群落进行了分析。优势细菌门为放线菌门、酸杆菌门、变形菌门、Poribacteria 门、PAUC34f 门、绿弯菌门和拟杆菌门，其中拟杆菌门、绿弯菌门和 Poribacteria 门的丰度在不同年份有所不同。在近似种水平（操作分类单元，OTUs，定义为 97%的序列相似性），未发现细菌丰富度和组成随时间发生重大变化。将近 50%的所有检测到的细菌共生体（205 个 OTUs 中的 96 个）是从所有采样年份中回收的，而由较少占优势的细菌组成的暂时性海绵微生物群则是特征性的。尽管有证据表明时间上共生体的维持，但个体之间存在令人惊讶的累积变异程度，所有被调查的海绵标本仅共享 27 个细菌 OTUs。古菌群落主要由一个候选属 Nitrosopumilus（泉古菌门）的共生体组成，该共生体以能够有氧氧化氨为亚硝酸盐而闻名。正如 PCR-DGGE 指纹图谱所记录的那样，只有少数细菌氨氧化菌在 S. spinosulus 中多年来一直存在。总之，S. spinosulus 的原核共生体表现出一种动态稳定状态，这种状态是由主要参与者的维持和不太常见的群落成员的更替之间的相互作用所塑造的，这种状态在时间和宿主个体中都存在，对整个共生体的功能没有明显的影响。
