由臺北近郊分離出一株能寄生於Aeromonas hydrophila 的噬菌孤菌，經多次重覆單離，並做 電子顯微鏡觀察鑑定後將其定名為Bdellovibrio A-1 ，並探討影響賓主關係的因子。噬茵弧菌產生 的最適溫度為25～29°C ，最適酸鹼質為ph 6.5 ，噬菌弧菌的生長需要添加二價陽離子Ca2+和 Mg2+ 噬菌祖菌對三種魚病細菌均會造成感染，而宿主細菌的添加濃度以4Xl08 cells較適合於噬 菌弧菌的生長。

The fish pathogens used in these experiments were Aeromonas hydrophila, Vibrio anguillarum and Edwardsiella tarda. These bacteria usually caused fish diseases in Taiwan, were kindly supplied by Dr. H. Y. Chung, Department of Zoology, National Taiwan University. The other organisms used in studying the activity spectrum of the isolate were Bacillus subtilis, Escherichia coli and Staphylococcus aureus which were the stock collection of our laboratory. Tryptic soy broth (TSB, Difeo) and nutrient broth (NB, Difeo) were used for the growth of fish pathogens and other tested hosts, respectively. Low nutrient medium: yeast extrac t and peptone (YP) broth contained Difeo yeast extract, 0.3%; Difeo peptone, 0.06% and 0.05 M Trisbuffer at pH 6.5 was prepared as descrihed by Stolp and Starr (1976). Dilute nutrient broth, NB/ 10; diluted tryptic soy broth, TSB/ 10 and diluted YP broth, YP /10 were prepared by adding 1 volume of NB or TSB or YP to 9 volumes of distilled-water. Double-layered agar plates were made by used of YP broth with the addition of 0.4 g /I of Ca2+, Mg2+ and 0.06% agar for the top layer; 1.2% agar for the bottom layer.