Studies on Genetically Engineered Larvicidal Cyanobacterium
Xu Xu-dony, Kong Ren-qiu, Hu Yu-xiang(Shandong Institute of Parasitic Diseases, Jining, 272133)
Expression of toxin genes of high toxic Bacillus in cyanobacteria is a potenial way to reach prolonged mosquito control. But for their low toxicity, the genetically engineered cyanobacteria can not be practically used hitheto, and in most reports, the recombinant cells need lysate for toxicity essays. In. this research, high larvicidal activity of recombinant Anabaena was developed by expressing the toxin genes of B. sphaericus from an Anabaena promoter. LC_(50)(24h.) of the larvicidal cyanobacterium to larvae of Culex pipiens was 2.31×10~4 cells/ml, and its practical use under outdoor conditions was demonstrated. Similar to B. sphaericus, its toxicity to larvae of Culex pipiens. Anopheles sinensis and Aedes albopictus decrvases in order. For its simple growth requirements and wide ecological adaptations, the larvicidal Anabaena might become a new weapon for prolonged control on mosquito.