蔬菜廢棄物堆肥化過程中添加可外分泌內葡聚醣酵素的枯草桿菌對堆肥過程之效應

Effects of the Addition of Bacillus subtilis That can Secrete Endoglucanase during Vegetable Waste Composting on the Composting Status

本研究目的在以纖維素為主成份的蔬菜廢棄物堆肥化過程中，添加經遺傳工程改良，具有外分泌可分解纖維素之內葡聚醣酵素能力的枯草桿菌菌株，對堆肥過程中之變化及影響。本研究是以廢棄花椰菜菜葉為堆肥材料，經切碎、濾乾，以改善其水份含量及碳氮比，再以小型反應器進行通氣堆肥處理。其中分為三組，分別為不添加枯草桿菌之空白對照組、添加沒有生產內葡聚醣酵素能力之一般枯草桿菌菌株及添加具外分泌內葡聚醣酵素能力之枯草桿菌轉殖菌株。結果發現有添加枯草桿菌會使第一個高溫尖峰提早到來，顯示增加微生物量可以加速易分解的有機物被分解。而只添加一般的枯草桿菌事無法縮短堆肥中，較不易分解的有機物被微生物分解利用的過程，但添加具外分泌內葡聚醣酵素能力之枯草桿菌轉殖株，則可使堆肥中半纖維素及纖維素較易被分解·縮短堆肥熟成的時間。最後檢測三組堆肥熟成後之品質，發現沒有太大之差異，顯示當添加枯草桿菌轉殖株以加速堆肥熟成時，並不影嚮其堆肥品質。

A genetically modified Bacillus subti/is, which can secrete recombinant endoglucanase, were added to vegetable waste compost and the effects as well as changes of the wastes compost were investigated. Vegetable、wastesused in this study was cauliflower leaves, which had been minced and dried before the composting proc­ess in order to obtain better water content and C/N ratio. After that, the vegetable wastes was sent to labora­tory-scale packed-bed reactor for further composting. Three treatments were given to the compost. In group one, transgenic Bacillus subtilis pWSB which can secrete endoglucanase were added; in second group, Bacillus sub­ti/is 0B430 which had no endoglucanase secretion were added; ai1d in the third group, no extra Bacillus subtilis was added in the composts. The results showed that the high temperature peak of composts in the first group ap­peared earlier than other treatments, which indicated that the adding of Bacillus subti/is in the early state of the composting increase the decomposition of cauliflower wastes. In the second group, no acceleration effect in the decomposition was observed. Endoglucanase, which secreted by the transgenic Bacillus subtilis pWSB, had the ability in the decomposing of hemicelluloses and celluloses and the decomposition time could be shortened Qualities of the above three composts were investigated, and no significant differences been observed, which in­dicated that the using of transgenic Bacillus subtilis had no influences with the quality of final composts product.