Purified Filtrate of Bacillus subtilis natto Culture 　Natto has the highest fibrinolytic activity 　among 200 foods from all over the world.

Natto, which has recently attracted attention throughout the world, is a familiar part of the Japanese diet. Japan has the highest average longevity in the world, which is partly attributed to a high consumption of soybean products, especially "natto". Dr. Sumi, a professor in the Department of Chemical Technology, College of Science and Industrial Technology, Kurashiki University of Science and the Arts, has clarified the beneficial effects of natto. In the US, Dr. Sumi found that the sticky part of natto, commonly called "threads", exhibited a strong fibrinolytic activity. He named the corresponding fibrinolytic enzyme "nattokinase" in 1980. Dr. Sumi conducted research on about 200 kinds of food from all over the world, and he found that natto had the highest fibrinolytic activity among all those foods. In 1986, Dr. Sumi presented the results of his research in Japan for the first time. Mass media such as NHK and major newspapers were quick to report these results, and natto received much favorable publicity. Since then, sales of natto in Japan have increased dramatically due to its reputation as an essential food for health maintenance. However, many people in Japan and other countries dislike natto because of the peculiar flavor and odor. For such people, a dried product of natto has been developed, in which the activity of nattokinase remains but the flavor and odor have been removed. This product enables easy oral ingestion of natto for everyone. There are several proteases in nattokinase (shown in the Table). Although subtilisin protease has long been known to be a nattokinase with an antithrombotic effect, it has become clear that bacillopeptidase F, one of serine proteases, has both the effect of dissolving thrombi and the effect of inhibiting the formation of thrombi. "NKCP (purified natto culture filtrate)" with bacillopeptidase, developed using an original technique, has been shown to be safe in many studies and is highly expected to prevent thrombosis as "the second generation nattokinase." To guarantee the activity of NKCP, researchers have developed qualitative and quantitative analysis methods to determine the content and activity of bacillopeptidase. Especially, to determine the quantification of bacillopeptidase, they established a sandwich ELISA method.