History of Natto and Its Relatives (1405-2012 - SoyInfo Center

table salt and several stimulants, of which amongst others
powdered mustard is preferred. It is chiefl y consumed in
Tokyo and the north-east districts of Japan, and for the
production of it Aizu [in Fukushima prefecture] is the noted
place. It is consumed in Tokyo in the summer time, but in the
north-east districts during the winter time, as these are rather
poor in vegetables at that season.”
In Section “V. The microbes of natto,” after
summarizing the published fi ndings of Dr. Yabe and Dr.
Sawamura, Muramatsu continues:
“Mr. Nonzen isolated several kinds of bacteria, among
them on bacillus to which Dr. Omori gave the name of
Bacillus viscosus natto and which, he said, is the principal
microbe that produces strong viscosity. The two kinds of
bacilli, which he named Bacillus odorans natto 1, and
Bacillus odorans natto 2, produce good aroma in natto; and
another one which he named Pseudomonas odorans natto,
produces also good aroma. The latter three did not produce
good natto, unless the material is inoculated also with B.
viscosus natto. Thus the author [Monzen] concluded that
there are necessary for the preparation of natto at least two
kinds of bacteria, one producing the peculiar aroma and the
other strong viscosity.
“Mr. Muto [1905] isolated several bacteria and
concludes that only one bacillus belonging to the B. subtilis
group is necessary for the production of natto.
Muramatsu investigated several kinds of natto prepared
in Tokyo, Aizu, and Morioka. He found that they all
contained the same microorganisms, among which three
bacilli (which he described) were the principal ones. He
learned that the three bacilli were similar to those isolated
previously by Sawamura, Muto and others. He also agreed
with Muto that only one bacillus was necessary for natto
fermentation, and that any one of the three would do the
job. He agreed with Sawamura that the organism similar to
B. natto Sawamura did not yield enough viscosity, however
Muramatsu discovered that whenever the fermentation was
carried out at high temperature (45ºC), the Bacillus No. 1
“produces the best quality of natto, providing much mucilage
[high viscosity] and good aroma. For each of the three bacilli
about 18 characteristics are examined and described.
For example: Bacillus No. 1. “Enzyme: Diastase
and proteolytic enzyme of tryptic nature are recognized.”
Note: All three bacilli produce diastase (which hydrolyzes
starches to make sugars) plus trypsin-like proteolytic
enzymes. This bacillus [Muramatsu’s No. 1] may be the
same as those which Dr. Sawamura represented as Bacillus
No. 2 and Bacillus viscosus Omori, and also that which
Mr. Muto thought was the only bacterium which produces
natto, though there are several differences in its behaviour
investigated by these author.”
“Bacillus No. 2. This bacillus develops more
energetically at high temperature and produces natto of the
best quality, forming much mucilage and a rather higher
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HISTORY OF NATTO AND ITS RELATIVES 69
aroma than Bacillus No. 1.”
“Bacillus No. 3. This bacillus develops most
energetically at 40ºC, and when it is developed on boiled
soya beans at this temperature it produces good natto
with strong viscosity and good aroma; but its mucilage is
somewhat less than Bacillus No. 1 and Bacillus No. 2.”
Note 1. This is the second report (after Sawamura) of
separating Bacillus natto from natto.
Note 2. This is the earliest document seen (Jan. 2012)
that mentions the word “enzyme” (or “enzymes”) in
connection with natto, or that describes the specifi c types of
enzymes produced by the natto bacteria. Address: College of
Agriculture and Dendrology, Morioka, Japan.
106. Sawamura, Shin. 1912. Ueber den Bacillus Natto
[Concerning the Bacillus Natto]. Chemiker-Zeitung
36(134):1306. Nov. 7. [Ger]
• Summary: Contains a brief description of how natto is
made and details of its chemical composition after 14 hours
and 7 days. Address: Tokyo.
107. Sawamura, Shin. 1913. On bacillus natto. J. of the
College of Agriculture, Tokyo Imperial University 5(2):189-
91. March. [1 ref. Eng]
• Summary: “Natto is an article of food prepared by leaving
boiled soy-beans wrapped in rice straw in a warm place
for a night, and thus making them ferment. Soy-beans of
natto are coated with a characteristic slimy substance. The
author separated formerly two species of bacilli from natto
obtained in Tokyo, No. 1 of which produced good fl avored
natto when inoculated to boiled soy-beans, and No. II
strongly slimy one. The former bacillus was considered to
be the chief actor in natto fermentation and received the
name of ‘Bacillus natto.’ In later years the author examined
bacteriologically many samples of natto obtained at various
localities, and found that the producer of natto is the same
in all cases, viz. ‘Bacillus natto.’ This bacillus can produce
natto of good fl avor and strong viscosity, and the presence of
other microbes is not necessary in the fermentation of natto.”
A detailed bacteriological description of Bacillus natto is
then given. “It was confi rmed by the previous investigation
that Bacillus natto produces a trypsin-like enzyme, and
decomposes protein of soy-beans... Bacillus natto produces
diastase, but reducing sugar was not found in natto thus
prepared.”
When B. natto acts on boiled soy beans at 35ºC for 14
hours and for 7 days, the following results are obtained,
respectively: Total nitrogen, 7.36, 7.42; insoluble albuminoid
nitrogen, 5.89, 2.10; soluble albuminoid nitrogen, 1.48,
5.31; soluble coagulable nitrogen, 0.31, 0.18; soluble noncoagulable
nitrogen, 0.32, 0.48; nitrogen, of peptone and
polypeptides, 0.21, 0.41; nitrogen, of arginine, histidine
and lysine, 0.07, 0.09; nitrogen of purine bases, 0.09, 0.14;
nitrogen precipitated by phosphotungstic acid, 0.11, 2.11;