The contributions of three great scientists to natto manufacturing

This time, I would like to talk about the history of modern natto manufacturing.

There is evidence of natto-selling activities in the Edo period. However, probably, stable production was not possible due to a lack of a standardized manufacturing method.

The modern natto manufacturing method was established in the Meiji and Taisho eras thanks to the achievements of the three great scientists.

① Dr. Kikuji Yabe

In 1894 (Meiji 27), Dr.Yabe was the first microbiologist to isolate microorganisms from natto at Agricultural University (currently the University of Tokyo). He published a natto bacteria paper in the journal of the Chemical Society of Japan. Four types of bacteria were isolated at this time, and extra bacteria were also mixed.

② Dr. Tadashi Sawamura

Dr. Sawamura of Agricultural University was the first person to isolate natto as a single bacterium in 1905 (Meiji 38). He named it Bacillus natto SAWAMURA.

It was the first time someone completed a single natto bacterium fermentation.

Before Dr. Sawamura’s discovery, natto was manufactured using rice straws and often became spoiled.

③ Dr. Jun Hanzawa

Dr. Hanzawa of Sapporo Agricultural College (currently Hokkaido University) was the first to establish a modern hygienic manufacturing method.

In 1918 (Taisho 7), Dr. Hanzawa created the Hanzawa-style natto manufacturing method. Steamed soybeans were placed in a clean warp wood (thin wooden board) container and planted with pure cultured natto bacteria.

He also started the distribution of purely cultured natto bacteria (seed bacteria), manufactured natto, and sold it as “university natto”. There is a record that the first inoculum was spread in 1912 by Professor Shunsuke Muramatsu of Morioka Higher Agricultural and Forestry School (currently Iwate University).

Dr. Hanzawa was appointed as the first professor of the Applied Mycology Course in 1916. It was the first Applied Microbiology Course in Japan, contributing to the development of Applied Microbiology for a quarter of a century.

He was also the first Japanese to study abroad at the Pasteur Institute in France. Dr. Hanzawa lived a long and prolific life, passing away in 1972 at 94 years.

The foundations created by these three scientists have enabled the manufacturing of natto to be perfected over the last 100 years. Science and tradition converge in a food that is one of Japan’s culinary treasures.