Application of phytoplankton

Abstract

This chapter describes the phytoplankton Chlorella species as model organisms and their application to metal toxicity evaluation. Metallic solutions used to assess metal toxicity were eluted from steel slag with leaching conditions based on JIS K 0058-1. This study also examined the development of methods to easily estimate not only the number of algae but also their algal activities. The concentrations of metal effluents from tested slags were almost all lower than environmental quality standards for effluent and drinking water. After incubation of Chlorella with culture media including eluates from the respective slags tested in this study, the effects of each eluate were investigated using microscopy and flow cytometry. Analyses of algal cells treated with each eluate revealed that eluate induced neither lethality nor growth inhibition. In addition to microscopic cell counting, bioassay using flow cytometry was used to estimate vigorous and aberrant algal growth simultaneously. Instead of exhibiting cytotoxicity, the addition of each eluate from steel slag enhanced algal growth.