Perini Laura, Gostinčar Cene, Anesio Alexandre Magno, Williamson Christopher, Tranter Martyn, Gunde-Cimerman Nina
Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia.
Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia.
Front Microbiol. 2019 Mar 21;10:557. doi: 10.3389/fmicb.2019.00557. eCollection 2019.
Recent studies have highlighted the importance of ice-algal blooms in driving darkening and therefore surface melt of the Greenland Ice Sheet (GrIS). However, the contribution of fungal and bacterial communities to this microbially driven albedo reduction remains unconstrained. To address this significant knowledge gap, fungi were isolated from key GrIS surface habitats (surface ice containing varying abundance of ice algae, supraglacial water, cryoconite holes, and snow), and a combination of cultivation and sequencing methods utilized to characterize the algal-associated fungal and bacterial diversity and abundance. Six hundred and ninety-seven taxa of fungi were obtained by amplicon sequencing and more than 200 fungal cultures belonging to 46 different species were isolated through cultivation approaches. Basidiomycota dominated in surface ice and water samples, and Ascomycota in snow samples. Amplicon sequencing revealed that bacteria were characterized by a higher diversity (883 taxa detected). Results from cultivation as well as ergosterol analyses suggested that surface ice dominated by ice algae and cryoconite holes supported the highest fungal biomass (10-10 CFU/100 ml) and that many fungal taxa recognized as endophytes and plant pathogens were associated with dark ice characterized by a high abundance of ice algae. This paper significantly advances this field of research by investigating for the first time the fungal abundance and diversity associated with algal blooms causing the darkening of the GrIS. There is a strong association between the abundance and diversity of fungal species and the blooming of algae on the surface ice of the Greenland Ice Sheet.
近期研究突显了冰藻大量繁殖在推动格陵兰冰盖（GrIS）变暗进而导致表面融化方面的重要性。然而，真菌和细菌群落对这种微生物驱动的反照率降低的贡献仍未明确。为填补这一重大知识空白，从格陵兰冰盖关键表面栖息地（含有不同丰度冰藻的表层冰、冰川上的水、冰尘洞和雪）分离出真菌，并采用培养和测序方法相结合的方式来表征与藻类相关的真菌和细菌的多样性及丰度。通过扩增子测序获得了697个真菌分类单元，并通过培养方法分离出了属于46个不同物种的200多种真菌培养物。担子菌门在表层冰和水样中占主导，而子囊菌门在雪样中占主导。扩增子测序显示细菌具有更高的多样性（检测到883个分类单元）。培养结果以及麦角固醇分析表明，以冰藻为主的表层冰和冰尘洞支持了最高的真菌生物量（10 - 10 CFU/100毫升），并且许多被认为是内生菌和植物病原体的真菌分类单元与以高丰度冰藻为特征的深色冰有关。本文通过首次研究与导致格陵兰冰盖变暗的藻华相关的真菌丰度和多样性，显著推进了该研究领域。格陵兰冰盖表层冰上真菌物种的丰度和多样性与藻类大量繁殖之间存在紧密联系。
