Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996-1605, USA.
Soil Cryology Laboratory, Institute of Physicochemical and Biological Problems in Soil Science, Institutskaya Street, Bldg. 2, Pushchino, Russia.
FEMS Microbiol Ecol. 2020 Nov 25;96(12). doi: 10.1093/femsec/fiaa229.
This work integrates cultivation studies of Siberian permafrost and analyses of metagenomes from different locations in the Arctic with the aim of obtaining insights into the community of photosynthetic microorganisms in perennially frozen deposits. Cyanobacteria and microalgae have been described in Arctic aquatic and surface soil environments, but their diversity and ability to withstand harsh conditions within the permafrost are still largely unknown. Community structure of photosynthetic organisms in permafrost sediments was explored using Arctic metagenomes available through the MG-RAST. Sequences affiliated with cyanobacteria represented from 0.25 to 3.03% of total sequences, followed by sequences affiliated with Streptophyta (algae and vascular plants) 0.01-0.45% and Chlorophyta (green algae) 0.01-0.1%. Enrichment and cultivation approaches revealed that cyanobacteria and green algae survive in permafrost and they could be revived during prolonged incubation at low light intensity. Among photosynthetic microorganisms isolated from permafrost, the filamentous Oscillatoria-like cyanobacteria and unicellular green algae of the genus Chlorella were dominant. Our findings suggest that permafrost cyanobacteria and green algae are expected to be effective members of the re-assembled community after permafrost thawing and soil collapse.
本研究整合了对西伯利亚永冻层的培养研究和对北极不同地点的宏基因组分析，旨在深入了解永冻土中光合微生物群落。已在北极水生和表土环境中描述了蓝细菌和微藻，但它们在永冻土中对恶劣条件的多样性和适应能力仍知之甚少。通过 MG-RAST 可获得北极宏基因组，利用其探索了永冻土沉积物中光合生物的群落结构。蓝细菌相关序列占总序列的 0.25%至 3.03%，其次是绿藻门（藻类和维管植物）相关序列 0.01%至 0.45%和绿藻门（绿藻）相关序列 0.01%至 0.1%。富集和培养方法表明，蓝细菌和绿藻在永冻土中存活，并且在低光照强度下长时间孵育时可以复苏。从永冻土中分离出的光合微生物中，丝状 Oscillatoria 样蓝细菌和单细胞绿藻属绿球藻占优势。我们的研究结果表明，在永冻土融化和土壤坍塌后，永冻土蓝细菌和绿藻有望成为重新组装群落的有效成员。
