Structure and function of gamma-polyglutamate gene in Bacillus subtilis(natto)

纳豆，即无盐发酵大豆，是由枯草芽孢杆菌（纳豆）生长在蒸熟的大豆上的生物作用而产生的一种老化产品。纳豆表面覆盖着一层粘稠的聚合物，接触后会形成又长又细的线。这种粘性物质的主要成分是γ -聚谷氨酸（γ - pga）。将纳豆枯草芽孢杆菌γ - pga高产率的遗传特性转移到不能产生γ - pga的马尔堡芽孢杆菌168上。吖啶橙处理纳豆枯草芽孢杆菌，在纳豆芽孢杆菌中检测到指定的pUH1，但其stg衍生物缺失5.8 kb质粒。克隆了纳豆质粒pUH1中产生γ - pga的特异基因，并确定了其核苷酸序列。在亚洲季风地区，有多种类似纳豆的无盐发酵大豆食品。这些类似纳豆的发酵食品被认为来自同一文化根源，这可能被称为“纳豆三角”。我们或许可以把这个地区的中心看作是本地区“生物技术”的根源。从这些类纳豆发酵大豆中分离得到发酵必需生物的纳豆质粒，并构建了纳豆质粒的系谱树。此外，还将讨论日本纳豆消费的不平衡，包括日本人的起源。

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.