优氯净对苏云金杆菌伴孢晶体消毒效果及机理的研究

DISINFECTANT EFFECT AND MECHANISM OF SODIUM DICHLOROISOCYANURATE ON BACILLUS THURINGIENSIS

苏云金杆菌(Bacillus thuringiensis,简称BT菌)的伴孢晶体被优氯净液处理后,在相差显微镜下观察,失去暗蓝色光泽,呈暗黑色,难溶于碱性缓冲液。虽能溶于昆虫的胃液,却失去致病性。用扫描电镜和SDS—聚丙烯酰胺凝胶电泳进一步研究,结果表明:优氯净能破坏伴孢晶体蛋白的一级和立体结构,使晶体蛋白失活,达到消毒的目的。消毒能力测定结果表明:1毫升0.03％有效氯优氯净液在3分钟内能消毒50微升BT菌液(3μg伴孢晶体/μl菌液)。消毒BT菌污染桑叶,用0.01％有效氯优氯净液浸泡3分钟即可。考虑到生产上的安全性,我们建议用0.05％有效氯优氯净消毒3—5分钟。

The parasporal crystal of Bacillus thuringiensis was treated with sodium dichloroisocyanurate and then observed under a phase contrast microscope. It was found that the dark blue fluorescence of parasporal crystal was lost and appeared to be deep black in color. The treated parasporal crystal was hard to dissolve in basic buffer solution and its pathogenicity was lost even though it can still dissolve in silkworm gut juice. More detailed researches with SDS-PAGE and scanning electron microscope show that sodium dichloroisocyanurate distroyed both primary and stereoscopic structure of parasporal crystal and make it lose its activity. The test of germicidal effect discovered that one millilitre (0.03%) sodium dichloroisocyanurate solution can disinfect 50 mi-crolitre BT solution within 3 minutes (3,μg parasporal crystal/μ1 BT solution). A good disinfection result can be achived when the mulberry leaves containminated by BT solution were treated with sodium dichloroisocyanurate (0. 01%) in three minutes. 0. 05% density with 3 minutes is suggested to be used in the actural disinfection process of the containminated mulberry leaves.