CHARACTERIZATION OF MOSQUITO-SPECIFIC BACILLUS-THURINGIENSIS STRAINS COISOLATED FROM A SOIL POPULATION

ISHII T OHBA M

T. Ishii et M. Ohba, CHARACTERIZATION OF MOSQUITO-SPECIFIC BACILLUS-THURINGIENSIS STRAINS COISOLATED FROM A SOIL POPULATION, Systematic and applied microbiology, 16(3), 1993, pp. 494-499

25

INGLESE

Article

Microbiology,"Biothechnology & Applied Migrobiology

Systematic and applied microbiology → ACNP

0723-2020

16

3

1993

494 - 499

ISI

0723-2020(1993)16:3<494:COMBSC>2.0.ZU;2-L

Ten isolates of Bacillus thuringiensis, coisolated from a single soil sample, were assigned to the three flagellar (H) antigenic serogroups: one isolate was identified as serovar kyushuensis (H antigen 11a:11c) , six were referable to serovar amagiensis (H antigen 29), and the oth ers belonged to a previously undescribed serovar. These ten isolates p roduced similar spherical to irregular-shaped parasporal inclusions. I n oral toxicity tests, they all exhibited moderate larvicidal activity to the mosquitoes, Aedes aegypti and Culex pipiens pallens, but not t o the silkworm, Bombyx mori, and the fall webworm, Hyphantria cunea. S DS-PAGE analysis revealed that the parasporal inclusions of these isol ates consisted of polypeptides of 25-28, 70-80, and 140-150 kDa, showi ng a high similarity in protein profiles between ten isolates and the type strain of serovar kyushuensis Strong immunological relationships were evident among inclusion proteins of these isolates and the type s train of kyushuensis, when examined by immunodiffusion and immunoblott ing tests with polyclonal antibodies raised against the whole paraspor al inclusion proteins. The results indicate that these B. thuringiensi s isolates from a single soil microhabitat produce closely related mos quito-specific toxins, although they belong to three different H serog roups.