| 摘要 |
<p>PURPOSE:To obtain a phage-resistant strain without accompanying the deterioration of activity, by converting a host strain free from a plasmid carrying the objective gene into a strain resistant to bacteriophage and introducing a plasmid carrying the objective gene into the mutant. CONSTITUTION:Plasmid pMTC-1 containing a gene coding tryptophan synthase is treated with a calcium chloride solution at a low temperature using E.coli k-12HB101 strain as a host and is introduced into the host cell to obtain OMT-2050 strain. Said OMT-2050 strain is cultured in a medium containing bacto-trypton, etc., by flask culture to generate a bacteriolytic phage. Purified phage OS1 is separated from the lysed solution. E.coli k-12HB101 strain is made to be resistant to phage with said phage liquid and the obtained resistant strain is cultured, a competent cell is prepared and a plasmid pMTC-1 is introduced to obtain a transformant OMT-2052 (FERM P-9528).</p> |
