Prokaryotic Nostoc, one of the world's most conspicuous and widespread algal genera (similar to eukaryotic algae, plants, and animals) is known to support a microbiome that influences host ecological roles. Past taxonomic characterizations of surface microbiota (epimicrobiota) of free‐living Nostoc sampled from freshwater systems employed 16S rRNA genes, typically amplicons. We compared taxa identified from 16S, 18S, 23S, and 28S rRNA gene sequences filtered from shotgun metagenomic sequence and used microscopy to illuminate epimicrobiota diversity for Nostoc sampled from a wetland in the northern Chilean Altiplano. Phylogenetic analysis and rRNA gene sequence abundance estimates indicated that the host was related to Nostoc punctiforme PCC 73102. Epimicrobiota were inferred to include 18 epicyanobacterial genera or uncultured taxa, six epieukaryotic algal genera, and 66 anoxygenic bacterial genera, all having average genomic coverage ≥90X. The epicyanobacteria Geitlerinemia, Oscillatoria, Phormidium, and an uncultured taxon were detected only by 16S rRNA gene; Gloeobacter and Pseudanabaena were detected using 16S and 23S; and Phormididesmis, Neosynechococcus, Symphothece, Aphanizomenon, Nodularia, Spirulina, Nodosilinea, Synechococcus, Cyanobium, and Anabaena (the latter corroborated by microscopy), plus two uncultured cyanobacterial taxa (JSC12, O77) were detected only by 23S rRNA gene sequences. Three chlamydomonad and two heterotrophic stramenopiles genera were inferred from 18S; the streptophyte green alga Chaetosphaeridium globosum was detected by microscopy and 28S rRNA genes, but not 18S rRNA genes. Overall, >60% of epimicrobial taxa were detected by markers other than 16S rRNA genes. Some algal taxa observed microscopically were not detected from sequence data. Results indicate that multiple taxonomic markers derived from metagenomic sequence data and microscopy increase epimicrobiota detection.

中文翻译：

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弹枪的宏基因组学和显微镜检查表明，智利北部湿地诺斯托克（蓝藻细菌）的表微生物群中存在多种蓝藻，其他细菌和微真核生物。

世界上最引人注目和最广泛的藻类之一（类似于真核藻类，植物和动物），原核能发纳能够支持影响宿主生态功能的微生物组。从淡水系统中采样的自由活动Nostoc的表面微生物群（epimicrobiota）的过去分类学特征使用了16S rRNA基因，通常是扩增子。我们比较了从shot弹枪宏基因组序列过滤的16S，18S，23S和28S rRNA基因序列中鉴定的分类单元，并使用显微镜阐明了从智利北部高原湿地采样的Nostoc的表生菌群多样性。系统发育分析和rRNA基因序列的丰富度估计表明宿主与点状猪鼻孔菌有关。PCC 73102.推断上微生物群包括18个表兰细菌属或未培养的类群，6个表真核藻类和66个产氧细菌类，它们的平均基因组覆盖率均≥90X。的epicyanobacteria Geitlerinemia，颤，席藻，和未培养的分类单元只通过16S rRNA基因检测; 用16S和23S检测了古细菌和假单胞菌；和Phormididesmis，Neosynechococcus，Symphothece，束丝，节球，螺旋藻，Nodosilinea，聚球藻，Cyanobium和鱼腥藻（后者通过显微镜证实），加上两个未培养蓝藻类群（JSC12，O77）通过23S rRNA基因序列仅检测。从18S推断出3个衣原体和2个异养的stramenopiles属。显微镜和28S rRNA基因检测到链霉菌绿藻球藻Chaetosphaeridium globosum，而18S rRNA基因检测不到。总体而言，通过除16S rRNA基因以外的其他标记检测到了超过60％的微生物分类群。从序列数据中未检测到一些在显微镜下观察到的藻类。结果表明，源自宏基因组序列数据和显微镜的多种生物分类标记可增加表观微生物群的检测。