Microbial communities in the water column of the ferruginous meromictic Lake La Cruz (Spain)

Ferruginous meromictic lakes are considered potential modern analogues of an ancient anoxic, iron-rich Archaean Ocean. We determined microbial community structures in the water column of Lake La Cruz (Spain) using 16S amplicon sequencing. Microbial community structures were related to detailed physical, chemical and isotope data, as well as rate measurements of key biogeochemical processes (methane oxidation rates, N2O transformation rates). The two step library preparation protocol was done using 18 PCR cycles in the first PCR, and for comparison with 25 PCR cycles, to evaluate the effect of the number of amplification cycles on the obtained community structure data and corresponding diversity measures.

含铁半混合湖（ferruginous meromictic lake）被认为是太古宙缺氧富铁海洋的潜在现代类比物。本研究借助16S扩增子测序（16S amplicon sequencing）解析了西班牙拉克鲁斯湖（Lake La Cruz）水柱中的微生物群落结构，并将该群落结构与详尽的物理、化学及同位素数据，以及关键生物地球化学过程的速率测定结果（甲烷氧化速率、一氧化二氮转化速率）进行关联分析。本研究采用两步法文库制备方案：首轮PCR使用18个扩增循环，并设置25个循环的对照组进行比较，以评估扩增循环数对所得群落结构数据及相应多样性指标的影响。