| 摘要 |
PURPOSE:To suppress the function of tryptophan repressor, and to increase the content of tryptophan synthase, by culturing a bacterial strain having a tryptophan repressor homologous gene in a medium containing indoleacrylic acid at a specific concentration. CONSTITUTION:A bacterial strain belonging to Escherichia genus and having a tryptophan repressor homologous gene is cultured in a medium containing 0- 1wt% organic nitrogen source in terms of nitrogen, and containing indoleacrylic acid or its salt at the final concentration of at least 25mug/ml (preferably 80- 200mug/ml) until the end of the logarithmic growth stage. The bacterial strain used in the above process is e.g. the Escherichia coli strain obtained by the transformation with plasmid having the gene fraction of tryptophan synthase originated from Escherichia coli K-12 and the gene fraction controlling the proliferation of the F-factor plasmid. |
