Smart Water Research Centre, Australian Rivers Institute, School of Environment, Griffith University, Southport, Queensland 4222, Australia.
Environ Sci Process Impacts. 2015 May;17(5):947-55. doi: 10.1039/c5em00012b. Epub 2015 Apr 7.
Bioassays using naturally luminescent bacteria are commonly used to assess the toxicity of environmental contaminants, detected by a decrease in luminescence. Typically, this has involved the use of commercial test kits such as Microtox and ToxScreen. These commercial assays, however, have limitations for routine environmental monitoring, including the need for specialized equipment, a low throughput and high on-going costs. There is therefore a need to develop a bacteria bioassay that is sensitive, high-throughput and cost effective. This study presents the development and application of the BLT-Screen (Bacterial Luminescence Toxicity Screen), a 96-well plate bioassay using Photobacterium leiognathi. During development of the method, the concentration of the phosphate buffer in the experimental medium was adjusted to maximize the sensitivity of the assay, and protocols for analyzing both solid-phase extracts and raw water samples were established. A range of organic compounds and metals were analyzed in the assay, as well as extracts of various water samples, including drinking water, wastewater effluent and river water. The IC50 values of the organic compounds and metals tested in the BLT-Screen were comparable to previously published ToxScreen and Microtox data. In addition, the assay was sensitive enough to detect toxicity in all water types tested, and performed equally well for both solid-phase extracts and raw water samples. The BLT-Screen therefore presents a cost-effective, sensitive and high throughput method for testing the toxicity of environmental contaminants in a range of water types that has widespread applications for research, as well as for routine monitoring and operation of wastewater and drinking water plants.
使用自然发光细菌的生物测定法通常用于评估环境污染物的毒性，其通过发光强度降低来检测。通常，这涉及使用商业测试试剂盒，如 Microtox 和 ToxScreen。然而，这些商业测定法在常规环境监测方面存在局限性，包括需要专用设备、低通量和高持续成本。因此，需要开发一种灵敏、高通量且具有成本效益的细菌生物测定法。本研究介绍了 BLT-Screen（细菌发光毒性筛查）的开发和应用，这是一种使用 Photobacterium leiognathi 的 96 孔板生物测定法。在方法开发过程中，调整了实验培养基中磷酸盐缓冲液的浓度，以最大限度地提高测定的灵敏度，并建立了分析固相萃取物和原水样品的方案。在测定中分析了一系列有机化合物和金属，以及各种水样的提取物，包括饮用水、废水和河水。在 BLT-Screen 中测试的有机化合物和金属的 IC50 值与先前发表的 ToxScreen 和 Microtox 数据相当。此外，该测定法足够灵敏，能够检测所有测试水样的毒性，并且对固相萃取物和原水样品的性能同样出色。因此，BLT-Screen 为在广泛应用于研究以及废水和饮用水厂的常规监测和运行的一系列水样中测试环境污染物的毒性提供了一种具有成本效益、灵敏和高通量的方法。
