Spherical parasporal inclusions of the Lepidoptera-specific and Coleoptera-specific Bacillus thuringiensis strains: A comparative electron microscopic study
N. Wasano et al., Spherical parasporal inclusions of the Lepidoptera-specific and Coleoptera-specific Bacillus thuringiensis strains: A comparative electron microscopic study, CURR MICROB, 40(2), 2000, pp. 128-131
Four Lepidoptera-specific Bacillus thuringiensis strains that belong to the
four H serogroups (serovars sumiyoshiensis, fukuokaensis, darmstadiensis,
and japonensis) and a Coleoptera (Scarabaeidae)specific strain belonging to
serovar japonensis were examined for comparative ultrastructure of spheric
al parasporal inclusions. The prominent feature of the inclusions of the Le
pidoptera-specific strains was the existence of thick, highly electron-dens
e envelopes surrounding a homogeneous protein matrix. The envelopes were 15
.0-66.7 nm thick and consisted of 5-12 layers of membrane. This is also the
case with inclusions of a Coleoptera-specific strain. The ultrastructure o
f inclusions from the five strains was in marked contrast to that of the bi
pyramidal parasporal inclusions produced by a Lepidoptera-specific serovar
sotto strain.