Study on Solid Fermentation Conditions of Bacillus natto

In order to optimize solid fermentation conditions of Bacillus natto,the effect of seed age,inoculum size,initial pH value and moisture of culture medium,solid fermentation time and temperature on solid fermentation were carefully studied.The most optimum solid fermentation conditions of Bacillus natto were obtained by L9(34)orthogonal experiment and shown as follows: seed age 17 h,inoculum size 7%,initial pH value 8.0,initial moisture 70%,solid fermentation temperature 37 ℃ and solid fermentation time 5 d.By the optimimum conditions the total bacterium and total spores achieved at 3.4×1010 cfu/g,1.8×109 cfu/g repectively.