| Soybean meal-solvent is a kind of by-product by soybean through leaching method. Soybean meal is rich in protein and mineral et al. Essential amino-acids composition proportion of soybean meal is very good. There are several of anti-nutritional factors in soybean meal, in a certain extent has affected the soybean meal in the animal husbandry application, although soybean meal main as protein feed in the animal husbandry industry kind of role for long. In order to better development and soybean meal, expanding soybean meal application way by using, we screened a strain M1 which could degrade crude protein in soybean meal, with soybean meal as the main fermentation substrates; ferment degrade soybean meal crude protein to product amino acids and small molecular peptide.The main research result are as follows:(1) The optimal fermentation conditions in 5L fermenter was mounting fluid quantity 3L, ventilation 250 L/h, temperature 38℃, stirring speed 250 r/min, inoculation volume 5%. On these optimum conditions, amino nitrogen content in fermentation liquid could arrive at 831ug/mL. Degradation effect of soybean crude protein was fine.(2) Then scale up with 100 L fermenter according to KLa equal principle and actual work experience. After being fermented the soybean meal crude protein degradation rate reached 88.57% was better than the degradation rate 73.80% in shaking culture, amino nitrogen content reached 1.05 mg/mL. Trial-production can be performed.(3) Though the preliminary study on high density fermentation, I consider that 38℃was the best temperature, appropriate improve ventilation and fermenter air pressure help improve dissolved oxygen rate when I use the strain M1 to ferment soybean meal to product amino acids and small molecular peptide with 15 L fermenter. Results show that the biomass can achieve 90×108/mL and the content of amino nitrogen can achieve 1.4mg/ml in the condition that ventilation was 800L/h, fermenter air pressure is 0.08mPa.When in the industrial production further improve ventilation was feasible, and further improve fermenter air pressure was unnecessary because it will improved the equipment requirements and increased risk. (4) Defoaming was an important part of fermentation cost in industrial production. The result shows that adding 3‰defoaming could made the fermentation success, and will not affect the product separation.(5) The result show that the method what we used to scale up from 5 L fermenter to 100L fermenter is feasible when I scale up to 500 L fermenter. Amino nitrogen content reached about 1.4mg/mL.14 kinds of amino acids was detected in the zymotic fluid and total animo acids content reached 154.37 mg/ml.And the result is steady and better than the result in small-scale fermentation. |
