| 摘要 |
<p>Contaminating arylsulfatase in a lactase preparation causes the generation of unpleasant and offensive taste and odor in a food such as a milk product to which the lactase preparation is added. To overcome this problem, it is required to establish a method for measuring arylsulfatase at a high sensitivity. It is also required therefor to develop a lactase preparation in which the content of contaminating arylsulfatase is minimized or, preferably, a lactase preparation from which arylsulfatase is completely removed. A lactase preparation, which is produced by using, as a starting material, a liquid culture medium of a diploid yeast strain carrying lactase gene and showing regulated expression of arylsulfatase protein, or a genetically-modified microorganism carrying lactase gene of a yeast having been transferred thereinto and showing regulated expression of arylsulfatase protein, which shows an arylsulfatase activity of 0.1% or lower on the basis of the lactase activity when measured by a fluorescence method.</p> |
