RELEASE-2022

Surface water microbe samples are collected at the same time and location as surface water cell count samples and surface water chemistry samples, which occurs once per month in wadeable streams (12 times per year), and every other month in lakes and rivers (6 times per year). In wadeable streams, samples are collected near the downstream S2 sensor location. In lakes and rivers, samples are collected near the buoy sensor set at 1 sampling depth in unstratified systems and up to 3 depths in stratified lakes. Surface water grab samples are filtered on 0.22 um Sterivex capsule filters, capped and flash-frozen in the field. The filters are stored and shipped frozen to an analytical facility for DNA sequence analysis using primer sets targeting the small subunit of the ribosomal RNA gene. Sequence data undergo QAQC and are processed bioinformatically using an in-house pipeline to identify unique sequence variants in the data and to taxonomically identify each sequence variant.

地表水微生物样本与地表水细胞计数样本、地表水化学样本同期同点位采集。采样频率如下：可涉水溪流（wadeable streams）每月采样1次，全年共12次；湖泊与河流每两月采样1次，全年共6次。可涉水溪流的采样点位设于下游S2传感器附近；湖泊与河流的采样点位则设于浮标传感器（buoy sensor）附近：不分层水体仅设置1个采样深度，分层湖泊（stratified lakes）最多设置3个采样深度。
本次采集的地表水瞬时水样（grab samples）均通过0.22 μm Sterivex胶囊式滤膜过滤，滤膜封装后于现场快速冷冻。滤膜全程以冷冻状态保存并运输至分析实验室，采用靶向核糖体RNA基因小亚基的引物组开展DNA序列分析。序列数据将先经过质量保证与质量控制（QAQC）流程，随后通过内部自研生物信息学流程进行处理：识别数据中的独特序列变体，并对每个序列变体开展分类学鉴定。