A novel mosquitocidal Bacillus thuringiensis strain LLP29 isolated from the phylloplane of Magnolia denudata
Lingling Zhang, Xiong Guan
(Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, People’s Republic of China)
Many Bacillus thuringiensis isolates were recovered from the phylloplanes of plants and Bryophyte in this study. Among them, the new strain LLP29 isolated from phylloplanes of Magnolia denudata was the most toxic to mosquitoes according to the results of the preliminary screening. To learn more about the characteristics of this novel mosquitocidal isolate, phase-contrast microscopy, insecticidal activity and PCR analysis were performed. The LC50 values of LLP29 against Aedes albopictus was 0.33 µg of protein/mg. Severa new genes, cry4Aa4, cry4Ba4, cry10Aa4, cry11Aa, cyt1Aa6, cyt2Ba15, were detected, cloned and named successfully. Bioassays on Ae. albopictus showed that LLP29 and the expressed BL21 of cry11Aa4 were both toxic to the 3rd-instar larvae. Meanwhile, the purified Cry11Aa4 protein was highly toxic against Ae. albopictus larvae and C6/36 cells. It would be useful for designing management strategies for mosquito biocontrol.
