sodium bicarbonate slowly the medium prepared by the above staled method was sterilized at 121 u00b0 c for 30 minutes and cooled followed by inoculation of 0 05 kg of a strain of bacillus natto commercially available from naruse fermentation chem lab and liquid cultivation at 40 u00b0 to 45 u00b0 c for about 48 hours under aerating and agitating conditions the medium should contain the alkaline protease for example 34 prolether 34 and 34 protease p 34 commercially available from amano pharmaceutical co ltd in this case soybean peptides can be further decomposed thus the alkaline protease is useful the amount of the protease is normally under 0 1 wt preferably 0 02 to 0 05 wt per 100 wt of the total fermentation product a mixture containing water the resultant culture broth was expressed and filtered followed by treatment with active carbon and perlite for deodoration and decoloration thereby obtaining a substantially transparent fermentation liquid i e fermentation extract the above stated expression and filteration are done by including filter cloth in the middle by what is called filter press a pressure of filter press is 550 kg 60 u00d7 60 cm 2 the above stated treatment with active carbon and prelite is done by injecting 600 kg of the above stated filtrate into a tank about 1 ton of content amount adding 1 kg of active carbon and 1 kg of perlile and mixing them thereafter by filtering the liquid treated by above stated method a substantially transparent fermentation liquid is obtained for preparation of medium mean grain size under 1 mm of powder is used as defatted rice bran and solid.