Study of the toxicity of Microcystis (blue-green algae) occurred in Lake Kasumigaura.

1.铜绿微囊藻K3A菌种平板培养方法的建立：铜绿微囊藻K3A稀释后接种于含有琼脂或琼脂糖的B12培养基上，可在琼脂上形成菌落，而在琼脂上不能形成菌落。琼脂糖凝胶的最适浓度为0.4%，倒置平板和铺展工艺的CFU值无明显差异。2.柏木湖微囊藻无菌菌株的分离。经过3次重复分离，15株微囊藻中有5株毒力强。3.毒力测定20株微囊藻的小鼠腹腔注射毒性。铜绿假单胞菌K-70(LD_(50)：250 mg/kg-小鼠体重)和K-139(LD_(50)：7.3 mg/kg)有毒性。4.K-139细胞提取的粗毒素对小鼠、绵羊、马和兔的红细胞均无溶血和凝血作用。新诺维辛对K-139细胞的处理(治愈)不影响毒素的产生。

1.Development of plate culture method for Microcystis species.When the diluted samples of Microcystis aeruginosa K3A were plated on B12 medium solidfied with agar or agarose, the colonies were occurred on agarose medium but not on agar medium. The most optimum concentration of agarose was 0.4 % and there was no difference of CFU between a pour plate and spreading teckniques.2.Isolation of axenic strains of Microcystis species from Lake Kasumigaura.An isolation of axenic strains was accomplished by a combination of plate and liquid culture. After an isolation procedure was repeated 3 times, five strains among 15 strains were axenic.3.ToxicityThe toxicity of 20 isolates of Microcystis was examined by intraperitoneal injection in mice. Two strains, M. aeruginosa K-70 (LD50:> 250mg/Kg-mouse weight) and M. aeruginosa k-139(LD50:7.3mg/Kg), were toxic. Microscopic observations of the dead mice receiving the K-139 disrupted cells showed that there were marked congestion and necrosis of the liver.4.Hemolysis and curingCrude toxin extracted from K-139 cells did not caused the hemolysis of erythrocytes of mouse, sheep, horse and rabbit. The novovicin treatment (curing) of K-139 cells did not influence a toxin production.