自养黄色杆菌杀钉螺的实验研究

Study on molluscicidal effect of Xanthobacter autotrophicus against Oncomelania hupensis

目的筛选出一种高效低毒廉价的微生物用以杀灭钉螺,并验证其效用。方法从钉螺孳生的土壤中分离得到自养黄色杆菌(Xanthobacterautotrophicus),分别采用浸泡法和接触法进行了杀螺实验。结果钉螺在1×106、2×106、3×106、4×106cfu/ml4个浓度的菌液浸泡24～72h,死亡率在1.3%～95.0%之间,48h的LD50是2.6×106cfu/ml,表明钉螺的死亡率与浸泡时间及菌液浓度具有明显的正相关关系。结论浓度为106cfu/ml以上的该菌液具有比较稳定的杀螺效果;浸泡法杀螺比接触法效果更好。

Objective To screen a kind of microorganism which is low poisonous for living creature but has high molluscicidal effect. Methods The Xanthobacter autotrophicus from the soil where Oncomelania hupensis lived were detached, then its molluscicidal effect against the snails were studied by the immersing and contacting methods, respectively. Results The death rates were 1.3%-95.0% immersed for 24 to 72 hours in the different density liquids (1×106,2×106,3×106,4×106 cfu/ml). The LD_~50 immersed for 48 hours was 2.6×106 cfu/ml. The death rates had obviously positive relationship with the immersing time and the density of the liquid. Conclusion The liquid which contains more than 106 cfu/ml Xanthobacter autotrophicus has a stable molluscicidal capacity, and the immersing method is better than the contacting method.[