利用二段式醱酵轉換豬排泄物化學性質變化之探討

Abstract

本研究擬利用兩階段醱酵技術，轉換豬排泄物的理化性質，以供進一步的利用。基質為固液分離後的乾燥豬糞，使用秀珍菇Pleurotus ostreatus為菌種在30℃下分別醱酵1~6週。醱酵過後的產物經過乾燥及高溫高壓殺菌後，再使用乳酸菌Lactobacillus delbrueckii subsp. bulgaricus 為菌種，並分成添加5%葡萄糖及未添加葡萄糖兩組來做比較，於37℃下厭氣醱酵1~3週。最終產物以固體分析方法對其理化性質進行分析。 第一階段真菌醱酵的結果顯示，豬糞中的粗脂肪含量在醱酵過程中不斷下降，還原醣含量在醱酵三週後出現最大值，平均含量約為2.86 g/L。粗蛋白含量則是在醱酵五週後最高，含量為9.61%，較一開始增加了1.84%。 第二階段乳酸醱酵的結果中，無添加葡萄糖方面，以真菌前處理三週的產物醱酵效果較好，粗蛋白含量約增加了0.5%，乳酸菌數亦可維持在106 CFU/mL左右。而添加了5%葡萄糖方面，整體粗蛋白表現皆為增加，乳酸菌數量也可維持一定的數量，但就經濟成本考量上，加入葡萄糖反而沒有造成太大的實質效益。 根據本實驗的研究結果，真菌前處理的時間以二週及三週較為合適，產生的還原醣量高，且根據後來的乳酸醱酵中粗蛋白含量與乳酸菌數量，顯示利用真菌醱酵能夠有效地先行分解豬糞培養基中的物質，產生可供乳酸菌使用的碳源。

In this study, swine manure was converted by Pleurotus ostreatus and Lactobacillus delbrueckii subsp. bulgaricus through the two-stage fermentation. In the first stage, the dry swine manure was inoculated with Pleurotus ostreatus and were fermented at 30℃ during 1~6 weeks. The products of the first stage were then dried and autoclaved to be the substrates of the second stage. In the second stage, 5% glucose was added as the feed supplement besides the products of the previous stage and were cultured with L. delbrueckii subsp. bulgaricus at 37℃ for 3 weeks. Also, another set of experiments without glucose addition were tested as the control experiments. In the first stage, the crude fat content were decreased during the period of fermentation were observed the highest reduced sugar concentration (2.78 g/L) at the third week and the crude protein content of the fifth week was 9.61% (w/w) which showed a 1.84% increase from the beginning. In the second stage, it seemed that the products of three weeks fungi fermentation could generate enough feed for Lactobacillus. After the second stage fermentation, the crude protein increased 0.5% and the bacteria count of Lactobacillus could maintain at a level of 106 CFU/mL without glucose addition. Although the crude protein content and the bacteria count were also good for those glucose addition experiments, it was not economical for extra change of the chemicals. In conclusion, the pretreatment of fungi could beneficially convert the swine manure to some short chain materials and hence increased the digestion efficiency of the consequent Lactobacillus fermentation.