Interactive Effect of Toxic Chemicals on Eucaryotic Micro-Organisms and Its Evaluation

微量有毒化学物质对环境的污染已成为关系到包括人类在内的各种生命生死存亡的重大问题之一。本研究的目的是评价化学品对生态系统的毒性。本研究涉及一个新的毒性测试协议的发展，并使用它在调查化学品的危险性评估的各种兴趣点。作为测试微生物，浮游植物（椭圆小球藻）和酵母（酿酒酵母）在这些调查中使用。关于毒性试验，研究了以下主题。(1)（2）重金属在浮游植物中的分布和相互毒性效应;（3）砷对某些蓝绿藻生长和产生霉味的影响;（4）用酵母检测化学品的DNA损伤;（5）浮游植物对重金属的生物富集;（6）酵母DNA修复缺陷突变体在化学品遗传毒性测试中的应用，（7）硫氢根离子在酿酒酵母抗甲基汞中的作用，（8）各种化学形态汞对酿酒酵母的毒性和生物累积研究，（9）利用酿酒酵母（Saccharomycescerevisiae）进行毒性评价，包括相互作用和DNA dame，以及高等植物对重金属的吸收。（10）土壤中几种镉化合物对糙米中金属含量的影响。（11）土壤中添加大量镉后，碳酸钙对小麦镉含量的影响。

Environmental pollution by toxic micro chemicals has been one of most serious issues related with a life-or-death question for all kinds of lives including human beings. The objects of this study is to evaluate toxicity of chemicals on ecosystems. This research deals with the development of a new toxicity testing protocol and with using it in investigating various points of interest in hazardous assessment of chemicals. As test micro-organisms, phytoplankton (Chlorella ellipsoidea) and yeast (Saccharomyces cerevisiae) were used in these investigations. Concerning the toxicity testing the following themes were investigated. (1) A short-term bioassay of toxic chemicals using Saccharomyces cerevisiae, (2) Interactive toxic effect and distribution of heavy metals in phytoplankton, (3) Effect of arsenic on the growth and musty odor production of selected blue-green algae, (4) DNA damage testing for chemicals using yeast, (5) Bio-concentration of heavy metals by phytoplankton, (6) Application of DNA repair-deficient mutants of yeast for genetic toxicity testing of chemicals, (7) Role of hydrosulfide ions in methylmercury resistance in Saccharomyces cerevisiae, (8) Toxicity and bioaccumulation study for the effect of various chemical forms of mercury on Saccharomyces cerevisiae, (9) Using Saccharomyces cerevisiae for toxicity assessment including interacting effects and DNA dame, and concerning heavy metal uptake by higher plants (10) The effect of several c admium compoubds in soil on the metal content of unpolished rice and (11) Effect of calcim carbonate on the cadmium content of wheat after addition of large amount of Cds to soil.