Yokoyama Hiroshi, Waki Miyoko, Moriya Naoko, Yasuda Tomoko, Tanaka Yasuo, Haga Kiyonori
Waste Recycling Research Team, National Institute of Livestock and Grassland Science (NILGS), 2 Ikenodai, Tsukuba, Ibaraki 305-0901, Japan.
Appl Microbiol Biotechnol. 2007 Feb;74(2):474-83. doi: 10.1007/s00253-006-0647-4. Epub 2006 Oct 5.
We examined hydrogen production from a dairy cow waste slurry (13.4 g of volatile solids per liter) by batch cultures in a temperature range from 37 to 85 degrees C, using microflora naturally present within the slurry. Without the addition of seed bacteria, hydrogen was produced by simply incubating the slurry, using the microflora within the slurry. Interestingly, two peaks of fermentation temperatures for hydrogen production from the slurry were observed at 60 and 75 degrees C (392 and 248 ml H2 per liter of slurry, respectively). After the termination of the hydrogen evolution, the microflora cultured at 60 degrees C displayed hydrogen-consuming activity, but hydrogen-consuming activity of the microflora cultured at 75 degrees C was not detected, at least for 24 days. At both 60 and 75 degrees C, the main by-product was acetate, and the optimum pH of the slurry for hydrogen production was around neutral. Bacteria related to hydrogen-producing moderate and extreme thermophiles, Clostridium thermocellum and Caldanaerobacter subterraneus, were detected in the slurries cultured at 60 and 75 degrees C, respectively, by denaturing gradient gel electrophoresis analyses, using the V3 region of 16S rDNA.
我们利用奶牛粪便浆液（每升含13.4克挥发性固体）中的天然微生物群落，通过分批培养在37至85摄氏度的温度范围内检测了氢气的产生。在不添加种子细菌的情况下，仅通过培养浆液中的微生物群落就能产生氢气。有趣的是，观察到该浆液产生氢气的发酵温度有两个峰值，分别在60和75摄氏度（每升浆液分别产生392和248毫升氢气）。在氢气释放终止后，在60摄氏度培养的微生物群落显示出消耗氢气的活性，但在75摄氏度培养的微生物群落至少在24天内未检测到消耗氢气的活性。在60和75摄氏度时，主要副产物都是乙酸盐，并且该浆液产生氢气的最佳pH值接近中性。通过变性梯度凝胶电泳分析，利用16S rDNA的V3区域，分别在60和75摄氏度培养的浆液中检测到了与产氢嗜中温和嗜热菌相关的细菌，即热纤梭菌和地下卡尔厌氧杆菌。
