Characterization of the mutant recombinant strain Pseudomonas putida IPM-36 exhibiting anticipating growth on a medium containing an inducer of the cry3A gene expression

摘要

Induction of the expression of the #delta#-endotoxin gene from Bacillus thuringiensis var. tenebrionis in the recombinant strain Pseudomonas putida IPM-36 negatively affected the viability and the growth rate of the culture. In order to optimize the insecticide production by the recombinant strain, mutant clones exhibiting anticipating growth on an inducer-containing medium were selected and studied. These clones differed in such aspects as the localization of mutations (either in plasmid pBTN11, carrying the cry3A gene, or in the chromosome), growth rate, or the level of #delta#-endotoxin synthesis after induction. Several mutants obtained proved much superior to P. putida IMP-36 in their structural and segregation stability, although they were as efficient as the original strain with respect to the production of the insecticide (protei Cry3A).