海藻を供試生物とした迅速かつ低労力な生物応答試験法の開発

抄録

  Bioassays are a useful tool for assessing the effect of effluents on organisms. However, there are only a few bioassays established using marine organisms. Moreover, conventional bioassay procedures require enormous amounts of time and labor. In this study, the authors have developed a rapid and simple bioassay using seaweed Pyropia yezoensis (conchospores and juvenile sporophytes), and bioassay tests were performed upon a 96 well microplate. The growth rate of an endpoint was determined by fluorescence intensity of chlorophyll using a plate reader. Through daily monitoring, this method could calculate the most minimum EC₅₀ for major heavy metals and toxic compounds. A trial with sporophytes could detect the effect of harmful substances more sensitively than a test using conchospores. In addition, the sporophytes test showed detection sensitivity to toxicants similar to that of a test with microalga Skeletonema marinoi-dohrnii. The sensitivities of conchospores and sporophytes tests to heavy metals were equal to those with various other seaweeds. We propose a rapid and simple seaweed bioassay using a microplate and a fluorescence plate reader.