Li Xuesong, Ma Hongzhi, Wang Qunhui, Matsumoto Shoichiro, Maeda Toshinari, Ogawa Hiroaki I
Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan.
Bioresour Technol. 2009 May;100(9):2475-81. doi: 10.1016/j.biortech.2008.12.019. Epub 2009 Jan 14.
A strain of sludge-lysing bacteria was isolated from waste activated sludge (WAS) in this study. The result of 16S rRNA gene analysis demonstrated that it was a species of new genus Brevibacillus (named Brevibacillus sp. KH3). The strain could release the protease with molecule weight of about 40 kDa which could enhance the efficiency of sludge thermophilic aerobic digestion. During the sterilized sludge digestion experiment inoculated with Brevibacillus sp. KH3, the maximum protease activity was 0.41 U/ml at pH 8 and 50 degrees C, and maximum TSS removal ratio achieved 32.8% after 120 h digestion at pH 8 and 50 degrees C. In the case of un-sterilized sludge digestion inoculated with Brevibacillus sp. KH3, TSS removal ratio in inoculated-group was 54.8%, increasing at 11.86% compared with un-inoculation (46.2%). The result demonstrated that inoculation of Brevibacillus sp. KH3 could help to degrade the EPS and promote the collapse of cells and inhibit the growth of certain kinds of microorganisms. It indicated that Brevibacillus sp. KH3 strain had a high potential to enhance WAS-degradation efficiency in thermophilic aerobic digestion.
本研究从废弃活性污泥（WAS）中分离出一株污泥溶解菌。16S rRNA基因分析结果表明，它是短芽孢杆菌属的一个新物种（命名为短芽孢杆菌KH3）。该菌株可释放分子量约为40 kDa的蛋白酶，这可以提高污泥嗜热好氧消化的效率。在接种短芽孢杆菌KH3的灭菌污泥消化实验中，在pH 8和50℃条件下，最大蛋白酶活性为0.41 U/ml，在pH 8和50℃条件下消化120 h后，最大总悬浮固体（TSS）去除率达到32.8%。在接种短芽孢杆菌KH3的未灭菌污泥消化实验中，接种组的TSS去除率为54.8%，比未接种组（46.2%）提高了11.86%。结果表明，接种短芽孢杆菌KH3有助于降解胞外聚合物（EPS），促进细胞解体，并抑制某些种类微生物的生长。这表明短芽孢杆菌KH3菌株在提高嗜热好氧消化中废弃活性污泥降解效率方面具有很大潜力。
