| 摘要 |
NEW MATERIAL:A plasmid containing a biotin.operator, a promoter governed with the biotin.operator and marker gene governed with the aforementioned promoter. USE:For producing biotin useful for improving sensitivity of diagnostic agents, etc., by genetic engineering. PREPARATION:For example, DNA is extracted from a microorganism having the ability to produce the biotin and treated with a restriction enzyme to select a DNA sequence containing a biotin.operator region. The resultant region is then linked to a promoter governed with the biotin.operator and a suitable marker gene governed with the aforementioned promoter to prepare a plasmid capable of selecting a biotin inhibition releasing microorganism. The resultant plasmid is subsequently introduced into a microorganism and a strain capable of expressing the marker gene even in the presence of the biotin is then selected from the resultant transformant to afford the objective biotin inhibition releasing microorganism. |
