自来水中细菌宏基因组 DNA的浓度与细菌菌落总数的相关性分析

摘要

分析自来水中细菌宏基因组DNA浓度与细菌菌落总数之间的相关性，探索新的自来水细菌菌落总数检测方法。采用国标法检测自来水中的细菌菌落总数约为（165±5） CFU／mL，高于国标限值（100 CFU／mL）。通过计算得出，检测600 mL本实验水样中的细菌菌落总数相当于检测1000 mL（1 L）100 CFU／mL的自来水。首先将600 mL及低于和高于该体积不同体积梯度的自来水经滤膜过滤收集菌体；然后使用细菌基因组提取试剂盒提取滤膜上的细菌宏基因组DNA，电泳分析提取的宏基因组质量；最后检测各个体积自来水宏基因组DNA浓度，根据检测结果分析自来水中宏基因组DNA含量与细菌菌落总数之间的相关性。提取的自来水宏基因组DNA主条带清晰，可以进行基因组DNA含量测定分析；自来水中细菌宏基因组DNA浓度与细菌菌落总数之间呈正相关的线性关系。建立一种通过检测自来水中细菌宏基因组DNA浓度来反映细菌菌落总数的检测方法，检测灵敏度可达7 CFU／mL，且省时、重复性好。%Through analyzing the correlation between the bacterial metagenomic DNA concentration and the total count of bacterial colonies in drinking water, we explore a new method for the detection of total number of bacterial colonies in drinking water.The total number of bacteria colonies in the water from our lab was detected by a tradi-tional technology, and it was about ( 165 ±5 ) CFU/mL, which is higher than 100 CFU/mL that is the security boundary value which was made by Chinese health department in 2006.To limit the total number of bacterial colo-nies within 100 CFU/mL,the volume of the detection sample must below 600 mL.Firstly, the sample with different volumes higher or lower than 600 mL is treated with microfiltration; Secondly, extract the bacterial metagenomic DNA of filter membrane by Bacterial Genome Extraction Kit;Thirdly, analyze the DNA extracted by agarose gel e-lectrophoresis;Fourthly, determine the concentration of DNA extracted.Finally, analyze the correlation between the bacterial metagenomic DNA concentration and the total count of bacterial colonies in drinking water according to the experimental results.The bacterial metagenomic DNA extracted from different volumes of drinking water pro-duce clear bands, and the DNA contents are enough for further analysis;the correlation between the bacterial met-agenomic DNA concentration and the total count of bacterial colonies in drinking water is positive and linear.To es-tablish a new method for detection of total number of bacterial colonies by analyzing the bacterial metagenomic DNA concentration in drinking water, the detection sensitivity can reach 7 CFU/mL, and the method is time-saving and with good repetitiveness.