Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan, ROC.
Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan, ROC; Department of Biological Science and Technology, Meiho University, Pingtung 91202, Taiwan, ROC.
Water Res. 2014 Feb 1;49:416-25. doi: 10.1016/j.watres.2013.10.028. Epub 2013 Oct 18.
Geosmin is one of the most commonly detected off-flavor chemicals present in reservoirs and drinking water systems. Quantitative real-time PCR (qPCR) is useful for quantifying geosmin-producers by focusing on the gene encoding geosmin synthase, which is responsible for geosmin synthesis. In this study, several primers and probes were designed and evaluated to detect the geosmin synthase gene in cyanobacteria. The specificity of primer and probe sets was tested using 21 strains of laboratory cultured cyanobacteria isolated from surface waters in Australia (18) and Taiwan (2), including 6 strains with geosmin producing ability. The results showed that the primers designed in this study could successfully detect all geosmin producing strains tested. The selected primers were used in a qPCR assay, and the calibration curves were linear from 5 × 10(1) to 5 × 10(5) copies mL(-1), with a high correlation coefficient (R(2) = 0.999). This method was then applied to analyze samples taken from Myponga Reservoir, South Australia, during a cyanobacterial bloom event. The results showed good correlations between qPCR techniques and traditional methods, including cell counts determined by microscopy and geosmin concentration measured using gas chromatography (GC) coupled with a mass selective detector (MSD). Results demonstrate that qPCR could be used for tracking geosmin-producing cyanobacteria in drinking water reservoirs. The qPCR assay may provide water utilities with the ability to properly characterize a taste and odor episode and choose appropriate management and treatment options.
土腥素是水库和饮用水系统中最常见的异味化学物质之一。实时荧光定量 PCR（qPCR）通过聚焦编码土腥素合酶的基因，对土腥素产生菌进行定量，是一种有用的方法，土腥素合酶负责土腥素的合成。在这项研究中，设计并评估了几种引物和探针，以检测蓝藻中的土腥素合酶基因。使用从澳大利亚（18 株）和台湾（2 株）地表水分离的 21 株实验室培养的蓝藻菌株（其中 6 株具有产生土腥素的能力）测试了引物和探针组的特异性。结果表明，本研究设计的引物可以成功检测到所有测试的产生土腥素的菌株。选择的引物用于 qPCR 检测，校准曲线从 5×10(1)到 5×10(5)copies mL(-1)线性，相关系数（R(2)）高（为 0.999）。然后，该方法应用于分析南澳大利亚 Myponga 水库在蓝藻水华事件期间采集的样品。qPCR 技术与传统方法（包括显微镜下的细胞计数和气相色谱法（GC）与质量选择检测器（MSD）联用测量的土腥素浓度）之间具有良好的相关性。结果表明，qPCR 可用于跟踪饮用水库中的产土腥素蓝藻。qPCR 检测可以为水公用事业公司提供正确描述异味事件并选择适当的管理和处理方案的能力。
