|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1993 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1992 : ¥1,500,000 (Direct Cost : ¥1,500,000)
Natto, or non-salty fermented soybeans, is an aging product by the biological action of Bacillus subtilis(natto)grown on the steamed soybeans. Natto is covered with a viscous, sticky polymer that formed long, thin threads when touched. The main component of the viscous material is gamma-polyglutamate(gamma-PGA). The genetic character of high gamma-PGA productivity in B.subtilis(natto)was transferred to B.subtilis Marburg 168, which cannot produce gamma-PGA.Treatment of B.subtilis(natto)with acridine orange resulted designated pUH1 was detected in B.subtilis(natto)strain, but the stgderivatives were missing the 5.8-kb plasmid. The specific gene of natto plasmid pUH1, which is responsible for gamma-PGA production, has been cloned and the nucleotide sequence determined.
There are many kinds of natto-like non-salty fermented soybean foods in Monsoon Asia. These natto-like fermented foods are considered to have streamed from the same cultural roots, which may be termed as "Natto Triangle". We might probably consider the center of this area as the roots of "Biotechnology" of our region. The natto plasmids were detected from the essential organisms for fermentation isolated from these natto-like fermented soybeans the natto plasmids, and by constructing the genealogical tree of these plasmids.
Moreover, the unbalanced consumptions of natto in Japan would be discussed, including the origin of the Japanese.