The paper showed three methods (alkali, sonic and sonic-alkali treatment) for the preparation of the cell wall of natto bacteria and some chemical properties of the preparations.
1 ) The preparation obtained by alkali treatment contained no nucleic acid, while some impurities remained were observed with electronmicroscope.
2 ) The preparation obtained by sonic treatment contained a few per cent of nucleic acids.
3 ) Both nucleic acid and impurities observable with electronmicroscope were not detected in the preparation obtained by sonic-alkali combinated treatment, which was concluded to be an excellent method of preparing the cell wall of the organism.
4 ) Prepatations obtained by any methods above mentioned contained about 50 per cent of amino acids and about 15 per cent of amino sugars.
5 ) Preparations were attacked by lysozyme and lysozyme like enzymes of natto bacteria' but not attacked by pepsin and trypsin.
6 ) The cell wall of natto bacteria was considered as a polypeptide, containing some amino sugars, similar to those of the other strains of gram positive bacteria.