Abstract Preservation of environmental samples is an important step in maintaining the original microbial community until the nucleic acid extraction in the laboratory. Here, we collected activated sludge samples to both immediately extract nucleic acids (control) and submit to different storage/preservation methods for 48 h before nucleic acids extraction: room temperature storage, storage on ice, direct storage at −20 °C, rapid freezing in liquid nitrogen followed by storage at −20 °C, and preservation with TRIzol®, RNAlater®, and Nucleic Acid Preservation (NAP) buffers. Bacterial community was compared by high-throughput 16S rRNA gene sequencing from total DNA and RNA. Among the evaluated methods, TRIzol® and rapid freezing with liquid nitrogen were the least indicated, since they led to significant changes in the microbial community structure and abundance of functional groups involved in ammonia metabolism. Compared to control, storage on ice and NAP preserved more than 80% and 75% of genera at the DNA and RNA level respectively, indicating that these methods are the most suitable for storage/preservation of activated sludge samples intended for nucleic acids sequencing.

中文翻译：

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用于高通量核酸测序和细菌多样性分析的活性污泥样品保存方法比较

摘要 环境样品的保存是在实验室进行核酸提取之前保持原始微生物群落的重要步骤。在这里，我们收集活性污泥样品以立即提取核酸（对照）并在核酸提取前提交不同的储存/保存方法 48 小时：室温储存、冰上储存、-20°C 直接储存、快速冷冻在液氮中，然后在 -20 °C 下储存，并用 TRIzol®、RNAlater® 和核酸保存 (NAP) 缓冲液保存。通过对总 DNA 和 RNA 进行高通量 16S rRNA 基因测序来比较细菌群落。在所评估的方法中，TRIzol® 和液氮快速冷冻的指示最少，因为它们导致微生物群落结构和参与氨代谢的官能团丰度发生显着变化。与对照相比，冰上储存和 NAP 分别在 DNA 和 RNA 水平上保留了超过 80% 和 75% 的属，表明这些方法最适合用于核酸测序的活性污泥样品的储存/保存。