Primer sets used for qPCR of 16S rRNA and <em>amoA</em> genes from the cryoconite samples

Table 1. Primer sets used for qPCR of 16S rRNA and amoA genes from the cryoconite samples. Abstract The aggregation of surface debris particles on melting glaciers into larger units (cryoconite) provides microenvironments for various microorganisms and metabolic processes. Here we investigate the microbial community on the surface of Aldegondabreen, a valley glacier in Svalbard which is supplied with carbon and nutrients from different sources across its surface, including colonies of seabirds. We used a combination of geochemical analysis (of surface debris, ice and meltwater), quantitative polymerase chain reactions (targeting the 16S ribosomal ribonucleic acid and amoA genes), pyrosequencing and multivariate statistical analysis to suggest possible factors driving the ecology of prokaryotic microbes on the surface of Aldegondabreen and their potential role in nitrogen cycling. The combination of high nutrient input with subsidy from the bird colonies, supraglacial meltwater flow and the presence of fine, clay-like particles supports the formation of centimetre-scale cryoconite aggregates in some areas of the glacier surface. We show that a diverse microbial community is present, dominated by the cyanobacteria, Proteobacteria, Bacteroidetes, and Actinobacteria, that are well-known in supraglacial environments. Importantly, ammonia-oxidizing archaea were detected in the aggregates for the first time on an Arctic glacier.表1. 用于冰尘样本16S rRNA与amoA基因定量聚合酶链式反应（quantitative polymerase chain reaction，qPCR）的引物组 摘要：冰川表面的碎屑颗粒在融冰过程中聚集成更大的团聚体（冰尘，cryoconite），可为各类微生物与代谢过程提供微环境。本研究聚焦斯瓦尔巴群岛的山谷冰川阿尔贡达冰川（Aldegondabreen）表面的微生物群落，该冰川表面各处可通过多种途径获取碳与营养物质，其中包括海鸟繁殖群落。我们结合了针对表面碎屑、冰体与融水的地球化学分析、靶向16S核糖体核糖核酸（16S ribosomal ribonucleic acid，16S rRNA）与amoA基因的定量聚合酶链式反应（qPCR）、焦磷酸测序以及多元统计分析，以揭示驱动阿尔贡达冰川表面原核微生物生态的潜在影响因子，以及它们在氮循环中可能发挥的功能。研究表明，高营养输入与海鸟群落的养分补给、冰面融水径流以及细微黏土状颗粒的存在，共同促成了冰川表面部分区域内厘米级尺度冰尘团聚体的形成。本研究证实该区域存在多样的微生物群落，其优势类群为蓝细菌门、变形菌门、拟杆菌门与放线菌门——这些类群在冰面环境中已被广泛报道。尤为关键的是，本研究首次在北极冰川的冰尘团聚体中检测到氨氧化古菌。