earticle

영어

1-Deoxynojirimycin (DNJ), a D-glucose analogue with a nitrogen atom substituting for the ring oxygen, is a strong inhibitor of the intestinal a-glucosidase. DNJ has several promising biological activities, such as antidiabetic, antitumor, and antiviral activities. Nevertheless, only limited amounts of DNJ is available because it can be extracted from some higher plants including the mulberry tree or purified from culture broth of several soil bacteria such as Streptomyces sp. and Bacillus sp. In our previous study, a DNJ producing bacterium, Bacillus subtilis MORI, has been isolated from a Korean traditional fermented food, Chungkookjang. Here, we report the identification of DNJ biosynthetic genes from the genomic DNA library of B. subtilis MORI strain constructed in E. coli, by selecting clones showing a-glucosidase inhibition activity. After DNA sequencing and series of subcloning, we were able to identify the DNJ biosynthetic operon with three genes encoding a putative transaminase, phosphatase, and oxidoreductase, respectively. Our results suggest the possibility to establish a large scale microbial DNJ overproduction system through genetic engineering and process optimization.