Thiele Stefan, Storesund Julia E, Fernández-Méndez Mar, Assmy Philipp, Øvreås Lise
Department of Biological Science, University of Bergen, Thormøhlensgate 53 A/B, 5020 Bergen, Norway.
Bjerknes Centre for Climate Research, Jahnebakken 5, 5007 Bergen, Norway.
Microorganisms. 2022 Aug 10;10(8):1618. doi: 10.3390/microorganisms10081618.
The Arctic is warming 2-3 times faster than the global average, leading to a decrease in Arctic sea ice extent, thickness, and associated changes in sea ice structure. These changes impact sea ice habitat properties and the ice-associated ecosystems. Sea-ice algal blooms provide various algal-derived carbon sources for the bacterial and archaeal communities within the sea ice. Here, we detail the transition of these communities from winter through spring to early summer during the Norwegian young sea ICE (N-ICE2015) expedition. The winter community was dominated by the archaeon Nitrosopumilus and bacteria belonging to the (, and ), indicating that nitrogen-based metabolisms, particularly ammonia oxidation to nitrite by Nitrosopumilus was prevalent. At the onset of the vernal sea-ice algae bloom, the community shifted to the dominance of () and (), while Nitrosopumilus almost disappeared. The bioinformatically predicted carbohydrate-active enzymes increased during spring and summer, indicating that sea-ice algae-derived carbon sources are a strong driver of bacterial and archaeal community succession in Arctic sea ice during the change of seasons. This implies a succession from a nitrogen metabolism-based winter community to an algal-derived carbon metabolism-based spring/ summer community.
北极变暖的速度比全球平均速度快2至3倍，导致北极海冰范围、厚度减小，海冰结构也随之发生变化。这些变化影响着海冰栖息地特性以及与冰相关的生态系统。海冰藻华可为海冰内的细菌和古菌群落提供各种源自藻类的碳源。在此，我们详细介绍了在挪威年轻海冰（N - ICE2015）考察期间，这些群落从冬季到春季再到初夏的转变情况。冬季群落以古菌嗜亚硝化球菌属以及属于（、和）的细菌为主，这表明以氮为基础的代谢，特别是嗜亚硝化球菌属将氨氧化为亚硝酸盐的代谢很普遍。在春季海冰藻类开始大量繁殖时，群落转变为以（）和（）为主，而嗜亚硝化球菌属几乎消失。通过生物信息学预测的碳水化合物活性酶在春季和夏季有所增加，这表明源自海冰藻类的碳源是北极海冰在季节变化期间细菌和古菌群落演替的强大驱动力。这意味着从以氮代谢为基础的冬季群落演替为以藻类衍生碳代谢为基础的春季/夏季群落。
