Cawthron Institute, Nelson, New Zealand.
J Appl Microbiol. 2010 Dec;109(6):2011-8. doi: 10.1111/j.1365-2672.2010.04831.x.
The purpose of this study was to determine the variability in anatoxin-a (ATX) and homoanatoxin-a (HTX) concentrations in benthic cyanobacterial mats within sampling sites and to assess the applicability of using a PCR-based approach to determine ATX- and HTX-production potential.
ATX and HTX variability was investigated by collecting 15 samples from 10 × 10 m grids in seven rivers. ATX and HTX concentrations were determined using liquid chromatography-mass spectrometry (LC-MS). Samples from two sites contained no ATX or HTX and at one site ATX and HTX were detected in all samples. At four sites, both toxic and nontoxic samples co-occurred and these samples were sometimes spaced less than 1 m apart. PCR amplification of a region of a polyketide synthase (ks2, putatively involved in the biosynthetic pathway of ATX and HTX) successfully distinguished ATX-and-HTX- and non-ATX-and-HTX-producing cultured Phormidium strains. Results from environmental samples were more variable, and the results were in congruence with the LC-MS data in only 58% of samples.
Fine-scale spatial variability in ATX and HTX concentrations occurs among benthic cyanobacterial mats.
Multiple benthic cyanobacterial mat samples must be collected at a sampling site to provide an accurate assessment of ATX and HTX concentrations at that location. The PCR-based technique offers the potential to be a useful early warning technique.
本研究旨在确定底栖蓝藻席中anatoxin-a（ATX）和 homoanatoxin-a（HTX）浓度的变异性，并评估基于 PCR 的方法来确定 ATX 和 HTX 产生潜力的适用性。
通过在七个河流中从 10×10 m 的网格收集 15 个样本，调查了 ATX 和 HTX 的变异性。使用液相色谱-质谱（LC-MS）法测定 ATX 和 HTX 浓度。来自两个地点的样本不含 ATX 或 HTX，而一个地点的所有样本均检测到 ATX 和 HTX。在四个地点，有毒和无毒的样本同时存在，这些样本有时相隔不到 1 米。对聚酮合酶（ks2，推测参与 ATX 和 HTX 的生物合成途径）的一个区域进行 PCR 扩增，成功地区分了 ATX 和-HTX-和非-ATX 和-HTX-产生的培养 Phormidium 菌株。环境样本的结果更为多变，只有 58%的样本与 LC-MS 数据相符。
底栖蓝藻席中 ATX 和 HTX 浓度存在精细的空间变异性。
在一个采样点必须采集多个底栖蓝藻席样本，才能准确评估该地点的 ATX 和 HTX 浓度。基于 PCR 的技术具有成为有用的早期预警技术的潜力。
