背景:为了控制引起人类疾病的蚊媒,细菌生物农药目前正在使用。的确,最近对这些细菌试剂的抗性的发展阻碍了其应用。在这种情况下,寻找具有灭蚊活性的新型细菌剂是不可避免的。在这项研究中,从农田红壤中分离出一种新型灭蚊细菌。
目的:本研究的目的是从自然环境中分离和鉴定新的灭蚊菌。
方法:在2021-2022年期间从泰米尔纳德邦的Tirupathur区收集了土壤样品,南印度。将样品进行生物处理,以在合适的培养基(营养酵母盐培养基)中培养细菌菌落。72小时后,取出细菌细胞团并冻干。进行生物测定(蚊子毒性测定)以筛选细菌菌落的灭蚊效果。进一步分析了潜在的菌落,并确定了其在蚊子控制中的应用。
结果:根据ilvD基因序列分析,从红壤中筛选的新分离株被鉴定为苏云金芽孢杆菌亚种以色列(VCRCB647)。发现该菌株可能有效控制蚊子幼虫,和进一步的生化分析,细菌生长,生物量,和蛋白质含量进行了调查。新的分离物对非目标水生生物没有任何毒性作用。
结论:描述该新分离株(Bti)的灭蚊作用比Bti-H14的参考菌株高度显着,具有重要意义。结论是,这是首次报道BtiVCRCB647的本地菌株在控制蚊子方面非常有效。
BACKGROUND: To control mosquito vectors causing human diseases, bacterial biopesticides are currently in use. Indeed, the recent development of resistance to these bacterial agents has impeded its applications. Under these circumstances, the search for novel bacterial agents with mosquitocidal activity is unavoidable. In this study, a novel mosquitocidal bacterium was isolated from red soils of agricultural field.
OBJECTIVE: The objective of this study was to isolate and identify new mosquitocidal bacteria from the natural environment.
METHODS: Soil samples were collected during 2021-2022 from Tirupathur district of Tamil Nadu, South India. The samples were bioprocessed for culturing the bacterial colony in a suitable culture medium (Nutrient Yeast Salt Medium), and after 72 h, the bacterial cell mass was removed and lyophilized. Bioassays (mosquito toxicity assays) were carried out to screen the bacterial colonies for mosquitocidal effect. The potential colony was further analyzed, and identified for its application in mosquito control.
RESULTS: The new isolate screened from red soil was identified as Bacillus thuringiensis subspecies israelensis (VCRC B647) as per the ilvD gene sequence analysis. The strain was found to be potentially effective in controlling mosquito larvae, and further biochemical analyses, bacterial growth, biomass, and protein content were investigated. The new isolate did not show any toxic effect on nontarget aquatic organisms.
CONCLUSIONS: It is significant to depict that the mosquitocidal action of this new isolate (Bti) is highly significant than the reference strain of Bti-H14. It is concluded that this is the first report that an indigenous strain of Bti VCRC B647 is very effective in mosquito control.