枯草芽孢杆菌对草金鱼的毒害作用

Toxic effects of Bacillus subtilis on goldfish

通过在基础饲料中添加不同含量的枯草芽孢杆菌,制成枯草芽孢杆菌含量分别为0cfu/g,0.45×109cfu/g、0.9×109cfu/g、1.36×109cfu/g和1.81×109cfu/g的5种试验饲料,分别用以上5种饲料饲喂均重(19.0±0.5)g,均体长(8.2±0.3)cm草金鱼5 d,评估了饲料中不同枯草芽孢杆菌添加量对草金鱼的毒害作用。结果表明:在基础饲料中添加枯草芽孢杆菌的量低于0.9×109cfu/g时,试验前期(72 h之前)对草金鱼的毒害作用表现不明显,而72 h后其死亡率才出现明显的差异(P<0.05),而枯草芽孢杆菌含量高于0.9×109cfu/g的试验组中,整个过程中,草金鱼死亡率存在明显差异(P<0.05)。在本试验条件下,枯草芽孢杆菌对草金鱼在96 h的半致死含量为1.59×109cfu/g,120 h的半致死含量为1.23×109cfu/g,安全含量为0.22×109cfu/g。

In order to assess the toxic effects of different dietary of Bacillus subtilis on goldfish,Bacillus subtilis was added to Basic feed formulations at 0cfu / g,0. 45 × 109 cfu / g,0. 9 × 109 cfu / g,1. 36 × 109 cfu / g and 1. 81 × 109 cfu /g,respectively. Each diet of the five test feeds was fed to goldfish（ average weight： 19. 0 ± 0. 5 g,average body length： 8. 2 ± 0. 3 cm） for five days. The results showed that when the amount of Bacillus. subtilis added to the basic feed was less than 0. 9 × 109 cfu / g,at the period of early test（ before 72 h） the toxic effects on goldfish was not obvious（ P 〈0. 05）,and mortality after 72 h had only significant difference（ P 〈0. 05）,And the test group of Bacillus subtilis contained more than 0. 9 × 109 cfu / g,significant difference in mortality goldfish（ P 〈0. 05）. Under the experimental conditions of the final results,Bacillus subtilis on goldfish in 96 h semi-lethal levels was 1. 59 × 109 cfu / g,120 h semi-lethal levels was 1. 23 × 109 cfu / g,and security content was 0. 22 × 109 cfu / g.