| The purpose of this paper is to explore microbial fermentation process parameters of different feed ingredients, through the fermentation of feed raw materials the sensory index of p H change rate of dry matter(DMR) and reducing sugar content in index analysis of the contrast, summarizes different feed raw materials under different conditions of fermentation parameter, provide theoretical basis for scientific production fermented feed.The fermentation conditions were optimized by the effects of moisture content on fermentation quality. Using solid-fermentation to study corn, soybean meal, and cottonseed meal, the trial aimed to research the effect that different strains(Lactobacillus, yeast and bacillus subtilis) and fermented substrates of different moisture content according to sensory evaluation, change of substrate p H, and amount of probiotics retention. The time to reach stable p H values of materials with different water contents was different. Soybean has the longest time to reach stable p H value followed by cottonseed while corn has the shortest time under the condition of same water content. Water content significantly affected the fermentation processes of corn, soybean and cottonseed with no effect on initial p H. The count of the probiotics was also influenced by water content. When p H values reached steady state, cottonseed had the largest number of the probiotics followed by soybean and corn. The color and smell of three materials after fermented have distinctive features. But cottonseed had the highest viscosity followed by soybean and corn. These results indicated that the most suitable amount of water was fifty percent, when lactobacillus, yeast or bacillus subtilis fermented corn; And the most suitable amount of water was sixty percent, when soybean meal or cottonseed meal was fermented by lactobacillus or bacillus subtilis; The soybean meal and cottonseed meal were fermented with yeast, the most suitable amount of water was fifty percent.The experiment was conducted to optimize the proportion of different probiotics of fermentation on the soybean meal. Orthogonal design was used with three factors: inoculation of Lactobacillus, Bacillus subtilis and Yeast were determined by p H, DM recovery and the contents of reducing sugar with solid fermentation technics at 35~37 °C. Results showed that in the same fermentation time, when the proportion of Lactobacillus, Bacillus subtilis and Yeast was 3:4:1, the p H of fermented soybean meal was the lowest. However, when the ratio of Lactobacillus, Bacillus subtilis and Yeast became 2:3:2, the highest DMR in fermented soybean meal was observed. In addition, the ratio of Lactobacillus, Bacillus subtilis and Yeast that resulted in the highest content of reducing sugar was 5:3:1. The comprehensive evaluation value was best when the proportion of Lactobacillus, Bacillus subtilis and Yeast was 5:3:1, p H=5.26, DMR=92.65%. Under the present experimental setting, the best compound Lactobacillus, Bacillus subtilis and Yeast forms on quality of fermentation soybean meal was 5:3:1.Central composite design of response surface methodology(RSM) was employed to optimize lactobacillus content(X1: 4.5×106 ~ 5.5×106 cfu?g-1), bacillus subtilis content(X2: 9.0×106 ~ 1.1×107 cfu?g-1) and yeast content(X3: 5.50×106 ~ 7.0×106 cfu?g-1) of fermented cottonseed meal with low p H value, high dry matter recovery(DMR) and the reducing-sugar content. Results indicated that the data were adequately fitted into three second-order polynomial models. The lactobacillus content, bacillus subtilis content and yeast content were found to have significant linear, quadratic and interaction effects on p H value, the DMR and the reducing-sugar. The optimal extraction conditions were predicted to be lactobacillus content of 5.50×106 cfu?g-1, bacillus subtilis content of 1.08×107 cfu?g-1 and yeast content of 6.08×105 cfu?g-1. The p H value, DMR and the reducing sugar predicted by RSA were 5.01, 91.8% and 1.69%, respectively. The detection index obtained experimentally was close to its predicted values. The establishment of such model provides a good experimental basis employing RSM for optimizing the quantity of inoculation of lactobacillus, bacillus subtilis and yeast on fermentation.Through the study of lactic acid bacteria bacillus subtilis and yeast for different feed raw materials fermentation parameters, the influence of determined under the condition of 50% water content, the best ratio of strains lactobacillus fermented soybean meal: bacillus subtilis, yeast = 5:3:1, fermented cottonseed meal best content: 5.50×106 cfu·g-1, lactic acid bacteria bacillus subtilis content is 1.08×107 cfu·g-1, yeast addition amount of 6.08×105 cfu·g-1... |
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