Institute of Biology, 296 Splaiul Independenţei, 060031, Bucharest, Romania.
Emil Racoviţă Institute of Speleology, Clinicilor 5, Cluj-Napoca, 400006, Romania.
Sci Rep. 2018 Jul 4;8(1):10096. doi: 10.1038/s41598-018-28401-1.
Screening of 1,000-years old ice layers from the perennial ice block of Scărișoara Ice Cave (NW Romania) revealed the presence of fungal communities. Using culture-dependent methods and molecular techniques based on DGGE fingerprinting of 18S rRNA gene fragments and sequencing, we identified 50 cultured and 14 uncultured fungi in presently-forming, 400 and 900 years old ice layers, corresponding to 28 distinct operational taxonomic units (OTUs). The dominant ice-contained fungal OTUs were related to Ascomycota, Basidiomycota and Cryptomycota phyla. Representatives of Mucoromycota and Chytridiomycota were also isolated from recent and 400 years old ice samples. The cryophilic Mrakia stokesii was the most abundant fungal species found in the cave ice samples of all prospected ages, alongside other cryophilic fungi also identified in various glacial environments. Ice deposits formed during the Little Ice Age (dated between AD 1,250 and 1,850) appeared to have a higher fungal diversity than the ice layer formed during the Medieval Warm Period (prior to AD 1,250). A more complex fungal community adapted to low temperatures was obtained from all analyzed ice layers when cultivated at 4 °C as compared to 15 °C, suggesting the dominance of cold-adapted fungi in this glacial habitat. The fungal distribution in the analyzed cave ice layers revealed the presence of unique OTUs in different aged-formed ice deposits, as a first hint for putative further identification of fungal biomarkers for climate variations in this icy habitat. This is the first report on fungi from a rock-hosted cave ice block.
对来自罗马尼亚西北部斯卡里绍拉冰洞（Scărișoara Ice Cave）常年冰体的 1000 年冰层进行筛选，揭示了真菌群落的存在。使用基于 DGGE 指纹图谱和 18S rRNA 基因片段测序的依赖培养和非依赖培养的分子技术，我们在目前形成的、400 年和 900 年的冰层中鉴定出 50 种培养真菌和 14 种未培养真菌，对应 28 个不同的操作分类单元（OTU）。主要的含冰真菌 OTU 与子囊菌门、担子菌门和隐真菌门有关。最近和 400 年的冰样本中也分离到了毛霉门和壶菌门的代表。嗜冷的 Mrakia stokesii 是在洞穴冰样本中发现的最丰富的真菌物种，在各种冰川环境中也发现了其他嗜冷真菌。与中石器时代冰期（公元 1250 年至 1850 年）形成的冰层相比，小冰期（公元 1250 年之前）形成的冰层具有更高的真菌多样性。与在 15°C 下相比，在所有分析的冰层中，在 4°C 下培养时获得了对低温更适应的更复杂的真菌群落，这表明在这种冰川生境中，冷适应真菌占主导地位。对分析的洞穴冰层中的真菌分布的研究揭示了在不同年代形成的冰沉积物中存在独特的 OTU，这是对该冰生境中真菌生物标志物用于气候变化的进一步鉴定的第一个暗示。这是关于来自岩栖洞穴冰块的真菌的首次报道。
