Open AccessParasporal bodies of Bacillus thuringiensis subsp. morrisoni (PG‐14) and Bacillus thuringiensis subsp. israelensis are similar in protein composition and toxicity
Author(s) -
Ibarra Jorge E.,
Federici Brian A.
Publication year - 1986
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1986.tb01353.x
Subject(s) - bacillus thuringiensis , bacillales , toxin , biology , microbiology and biotechnology , bacillaceae , gel electrophoresis , sodium dodecyl sulfate , bioassay , polyacrylamide gel electrophoresis , aedes aegypti , bacteria , larva , biochemistry , bacillus subtilis , botany , enzyme , ecology , genetics
The mosquitocidal parasporal bodies of the PG‐14 isolate of Bacillus thuringiensis ssp. morrisoni and B. thuringiensis ssp. israelensis were purified on sodium bromide gradients and compared using sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) electron microscopy and bioassays against mosquito larvae. The parasporal bodies of both subspecies were spherical/ovoidal, approx. 0.7–1.2 μm in diameter, and contained major proteins of 28, 65, 126 and 135 kDa. In addition to these, the parasporal body of B. thuringiensis ssp. morrisoni contained at least one other major protein, of 144 kDa, which correlated with the presence of a quasi‐bi‐pyramidal inclusion not present in the B. thuringiensis ssp. israelensis parasporal body. The LC 50 for parasporal bodies of each subspecies was in the range of 3 ng/ml for fourth‐instars of Aedes aegypti . These results indicate that B. thuringiensis Serotype 8a:8b, which is generally considered to produce proteins toxic to lepidopterous insects, is capable of producing a protein toxin complement similar to B. thuringiensis Serotype 14.