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Received July 19, 2006; Revision received August 4, 2006
The influence of culture conditions and plasmids on immunoglobulin (Ig)-binding activity of two isogenic strains of Yersinia pseudotuberculosis (plasmid-free strain 48-82- and strain 48+82+ bearing plasmids pYV48 and pVM82) was studied. The highest activity was observed in the bacteria grown on glucose-containing liquid medium in the stationary growth phase. The Ig-binding activity of the bacteria cultured on the liquid medium at pH 6.0 was about 1.5-fold higher than that of the bacteria grown at pH 7.2. Expression of the Ig-binding proteins (IBPs) was most influenced by temperature of cultivation. The IBP biosynthesis was activated in the bacteria grown at 4°C and markedly decreased in those grown at 37°C. The Ig-binding activity of lysates from the bacteria was caused by proteins with molecular weights of 7-20 kD. The activities of the plasmid-free and plasmid-bearing Y. pseudotuberculosis strains (48-82- and 48+82+, respectively) were analyzed, and the plasmids were shown to have no effect on the IBP expression and biosynthesis, which seemed to be determined by chromosomal genes.
KEY WORDS: Yersinia pseudotuberculosis, immunoglobulin-binding proteins, culture conditions, plasmidsDOI: 10.1134/S0006297906110150