【摘要】：中國作為一個馬鈴薯大國,每年有大量的馬鈴薯被加工制成淀粉,而在這個過程中會伴隨產(chǎn)生大量的廢棄物如廢薯渣與汁水,其中含有大量的營養(yǎng)物質,直接排放不僅造成資源的大量浪費,還導致環(huán)境的嚴重破壞。本研究利用微生物的生長代謝對馬鈴薯薯渣進行發(fā)酵,并且將纖維素降解過程與單細胞蛋白生產(chǎn)相結合,將原本廢棄的營養(yǎng)物質進行加工利用,生產(chǎn)單細胞蛋白,制成動物喜食的飼料。通過實驗確定了發(fā)酵菌種生長特性,找到了復合微生物發(fā)酵馬鈴薯薯渣的最佳發(fā)酵條件,并且對發(fā)酵產(chǎn)物進行品質評價,最后利用數(shù)學方法對發(fā)酵體系進行了動力學分析。實驗選擇有纖維素降解能力的黑曲霉、產(chǎn)單細胞蛋白的釀酒酵母與地衣芽孢桿菌作為發(fā)酵菌種,分別測定各自生長曲線,結合還原糖的產(chǎn)生情況確定了發(fā)酵時各個菌種的添加時機以保證發(fā)揮最大功效,通過測定精蛋白變化情況結合經(jīng)濟成本問題綜合考慮確定發(fā)酵周期為4天。利用響應面優(yōu)化法得到發(fā)酵的最佳條件為p H為6.3,接種量為2.61%,溫度為33.94℃。通過驗證實驗,得到實驗值蛋白減少量為3.21 mg/m L,與理論值3.28 mg/m L基本一致。然后建立了有關馬鈴薯薯渣發(fā)酵的動力學模型,在對最佳條件下進行的發(fā)酵過程進行檢測,利用1stopt軟件對實驗數(shù)據(jù)進行擬合,分別解得菌體生長動力學、產(chǎn)物生成動力學、動物消耗動力學模型的未知參數(shù),確定了完整的數(shù)學公式,為以后的大型生產(chǎn)提供便利,指導工業(yè)應用。測定經(jīng)過發(fā)酵處理的汁水對比原始汁水COD去除率為72.99%。對發(fā)酵產(chǎn)物物理、化學、生物方面的品質進行簡單評價,纖維素與蛋白小顆粒在發(fā)酵后被分解破壞,利于動物消化,上清液中精蛋白含量由發(fā)酵前的4.58 mg/m L減為發(fā)酵后的1.37mg/m L,粗蛋白含量達到31.8%,檢測到的17種氨基酸含量在發(fā)酵后全部增加,總量達到15.8%,提高5.4倍。纖維素降解率為55.4%,最終還原糖剩余量為0.015mg/m L。
[Abstract]:China, as a large potato country, has a large number of potatoes processed into starch every year, and in the process, it will produce a lot of waste such as waste potato dregs and juices, which contains a lot of nutrients. Direct emissions not only lead to a large amount of waste of resources, but also lead to serious damage to the environment. In this study, potato dregs were fermented by microbial growth and metabolism, and the cellulose degradation process was combined with the production of single cell protein, and the waste nutrients were processed and utilized to produce single cell protein. Feed that makes animals like to eat. The growth characteristics of fermentation bacteria were determined by experiments, the optimum fermentation conditions of potato dregs by compound microorganism were found, and the quality of the fermentation products was evaluated. Finally, the kinetics of the fermentation system was analyzed by mathematical method. Aspergillus Niger with cellulose degradation ability, Saccharomyces cerevisiae and Bacillus licheniformis, which produce single cell protein, were selected as fermentation strains, and their growth curves were measured. Combined with the production of reducing sugar, the adding time of each strain during fermentation was determined to ensure the maximum effect. The fermentation period was determined to be 4 days by determining the changes of protamine and considering the economic cost. By using response surface optimization method, the optimum fermentation conditions were as follows: ph was 6.3, inoculation amount was 2.61 and temperature was 33.94 鈩，

本文編號：2243026