灭钉螺微生物的筛选及功效研究

Screening and molluscicidal activity of microorganism against Oncomelania hupensis

目的消灭钉螺是防治血吸虫病重要工作,筛选出一种高效、低毒、持久及价廉的杀螺细菌是有意义的探索。方法本文从钉螺孳生的土壤中筛选出具有杀螺作用的强毒菌株,分别制备成细菌发酵液、发酵上清液和菌体悬液进行浸泡杀螺比较,取得了初步结果。结果经初筛,分离出4株(B8、B27、B36、B59)对钉螺具有毒性作用的细菌;灭螺实验结果表明,4株细菌的发酵液、发酵上清液和菌体悬液均显示出不同的毒杀作用,综合比较发现,B59菌株的灭螺效果最好,其次是B27、B36菌株,B8菌株最弱。在细菌发酵上清液各菌株间灭螺效果差异有统计学意义(χ2=21.286,P=0.002);各菌株发酵液的灭螺效果差异也有统计学意义(χ2=17.298,P=0.008);但各菌株菌体悬液之间的灭螺效果未显示统计学差异(χ2=7.579,P=0.271)。结论细菌的代谢产物,尤以B59菌株的发酵上清液有较好的灭螺功效。

We screened the efficient,durable,safe and inexpensive molluscicidal microorganisms against Oncomelania hupensis and observed the mollusicicidal effects of microorganism in this study.Bacteria with highly toxic to Oncomelania hupensis were screened from the soil samples of habitat.The bacteria were prepared into bacterial fermented liquor,fermented supernatant and bacteria suspension respectively.The mollusicicidal effects were tested in the experiment base of prevention and control schistosomiasis.The four strains（B8,B27,B36,and B59）which were highly toxic to Oncomelania hupensis were isolated by preliminary screening.Results of mollusicicidal effects showed that 4strains of bacteria different components including the fermented liquor,fermented supernatant and bacteria suspension were in different levels of toxicity to snails.According to the comprehensive comparison,B59 strain had the excellent molluscicidal activity.The second ones were B27 and B36strain.The last one was B8 strain.By the statistical analysis,mollusicicidal effects of the four strains were significant differences（χ^2=21.286,P=0.002）.mollusicicidal effect of the four strains were also significantly different（χ^2=17.298,P=0.008）.mollusicicidal effects of the four strains were not significantly different in the bacteria suspension（χ^2=7.579,P=0.271）.The fermented supernatant of B59 strain was significantly superior to other strains by mollusicicidal effect analysis.