CHARACTERS AND INSECTICIDAL POLYPEPTIDE OF A NEW STRAIN OF BACILLUS THURINGIENSIS SUBSP. KENYAE IN CHINA
中国Btken-Ag的特性及其杀虫毒肽的研究

A new strain of Bacillus thurinigiensis Bt with high toxicity againstnoctuidae larvae has been screened for many generations since isolated from larvaecandle of Aphomia gularts in Yiyang County, Jiangxi Province, in China. By comparison and analysis of results of physiological and biochemical test, flagella antigen identification and esterase type, the strain is identified as H4a-4c Bt serovar.kenyae. Since its crystal protein type and plasmid type are different from those ofBt serovar. kenyae's type 023. The strain is assigned a novel strain: Btken-Ag.Btken-Ag's parasporal crystals are multi-morphorous: bipyramid, cube, small irregular sphere and embedded. After UMT dissolve, PAGE and SDS-PAGE separationpreparation and analysis, it is found that its major insecticide component to Helio-this armigera is 61kD toxic protein. By ELISA homology analysis, it is found thatthis toxic protein has high homology with crystal protein of 023 and 7501 (H4a-4c), partly homology with that of HD-l(H3a-3b), but no homology with that ofBti(H14) and (Bacillus sphaericus) Ts-1 strain, in bioassay with larvae from Cu-lex pipiens, Pseudaletia unipuncta and Heliothis armigera, together with other tenBt strains, Btken-Ag is toxic to 3 star larvae of Culex pipiens; two isolates of Btken-Ag (b1-4 and H4-1) show higher toxicity than type strain 023 and HD-1 doto Pseudaletia unipuncta and Heliothis armigera.