HIGHLY PRODUCTIVE METHOD FOR GETTING SILMONA SALMONELLA STRENGTHENED STRAINS

摘要

1. A method of growing a weakened mutant strain of Salmonella typhi that has lost galactose epimerase activity and containing at least one copy of a recombinant DNA molecule containing an expression cassette, where the method includes the step of cultivating the strain in a buffer medium containing peptone, with approximately neutral pH at the fermentation scale, in which the amount of glucose in the medium during fermentation is adjusted so that the amount of glucose is reduced to zero until the stationary phase is reached. 2. The method according to claim 1, wherein glucose is not added to the medium during the fermentation process, and the initial amount of glucose is consumed until the stationary phase is reached. The method of claim 2, wherein the attenuated mutant strain of Salmonella typhi is Salmonella typhi Ty21a. 4. The method according to any one of paragraphs. 1 or 3, characterized in that the expression cassette is a eukaryotic expression cassette, preferably encoding a VEGF receptor protein, preferably a VEGF receptor protein selected from the group consisting of human VEGFR-2 and its homologue, the degree of homology of which is about 80 %, in particular, human VEGFR-2 having the amino acid sequence described in SEQ ID NO 1.5. The method according to any one of paragraphs. 1 or 3, characterized in that the buffer medium contains peptone of non-animal origin, where the buffer medium is preferably trypsin soy broth (TSB) of non-animal origin. 6. The method according to any one of paragraphs. 1 or 3, characterized in that the volume of the medium is at least about 10 l, preferably from about 10 l to 10,000 l, more preferably from about 30 l to 1000 l, most preferably from about 100 l to 500 l. 7 . The method according to any one of paragraphs. one