An existing bead-beating DNA extraction protocol was employed to compare the DNA extraction recovery and fragment quality of 6 different aeration diffuser biofilms. Escherichia coli, Gordonia amarae, and mixed liquor were used as controls. The fraction of total DNAbiofilm decreased monotonically with increasing number of beat beatings (BB) when the amount of DNA present was sufficient (>4 μgDNA/cm2), excluding the ceramic disk. While controls required only 2 BBs, 3 out of 5 BBs achieved ≥70% of total DNA (70.3 ± 1.7%) for 5 out of 6 biofilms. Quantitative polymerase chain reaction (PCR) analyses of 353 and 1,505 basepair (bp) amplicons from pure culture extracts showed target copy numbers were not degraded for the first 2 BBs, but the third BB decreased amplicon concentrations by 0.65 and 1.12 log for E. coli, and 0.39 and 0.40 log for G. amarae, respectively. The 353 bp fragment amplification from biofilm samples showed minimal degradation for the first 3 BBs. PCR and gel electrophoresis confirmed integrity of amplified 1,505 bp DNA fragments over the 5 BBs, except in the EDPM (75 mm diameter, tube) diffuser biofilm (4.98 ± 0.62 μgDNA/cm2). Taken together, this study showed type of diffuser membrane biofilms had no effects on extraction efficiency, but low DNA concentrations reduced extraction performance.

中文翻译：

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使用Bead-Beating方案比较不同曝气扩散器生物膜的DNA提取效率和重现性。

现有的敲打DNA提取方案用于比较6种不同曝气扩散器生物膜的DNA提取回收率和片段质量。大肠杆菌，G蚕和混合液用作对照。当存在的DNA量足够时（> 4μgDNA/ cm2），不包括陶瓷盘，总DNA生物膜的分数随拍打次数（BB）的增加而单调减少。对照仅需要2个BB，而6个生物膜中就有5个BB中有3个达到了总DNA的≥70％（70.3±1.7％）。对纯培养物提取物中353和1,505个碱基对（bp）扩增子的定量聚合酶链反应（PCR）分析显示，前两个BB的目标拷贝数未降低，但第三个BB降低了大肠杆菌的扩增子浓度0.65和1.12 log。 ，G的对数分别为0.39和0.40。mar菜。从生物膜样品中扩增的353 bp片段显示前3个BB的降解最小。PCR和凝胶电泳证实了在5个BB上扩增的1,505 bp DNA片段的完整性，除了EDPM（直径75毫米，试管）扩散生物膜（4.98±0.62μgDNA/ cm2）。两者合计，这项研究表明扩散膜生物膜的类型对提取效率没有影响，但是低DNA浓度会降低提取性能。