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在相同温度和初始发酵液条件下,采用DGGE指纹图谱结合沼气产量与成分,对批量式沼气发酵的3个发酵重复的分析,表明了沼气发酵体系中细菌类群丰富的多样性。随着发酵的进行,细菌绝对数量先增加后趋于稳定;细菌类群发生明显的变化,发酵时间越长,发酵前后的细菌类群区别越大;有的细菌类群始终保持优势,不受产气速率、甲烷含量和温度变化的影响;有的细菌类群在特定发酵时期处于优势地位,且与产气速率和甲烷含量的变化存在相关性;发酵前84天的DGGE分析表明,3个重复的细菌类群特别是优势类群的变化基本同步,但也存在一定区别,相似度在65%~83%之间。与细菌类群变化相对应,三个重复的产气速率和甲烷含量的变化也基本同步,在发酵前55天,5日产气量在2~8 L之间,甲烷体积百分数从65%下降到30%~45%之间。发酵60天到100天,产气速率迅速升高并达到高峰,高峰时的5日产气量达到20 L,甲烷体积百分数迅速升高并达到顶峰为72%~75%;从较短的发酵期间来看,3个重复的产气速率和甲烷含量也存较明显区别,这与3个重复在同一时期细菌类群存在一定的差异性相对应。
At the same temperature and initial fermentation conditions, the DGGE fingerprinting combined with biogas production and composition analysis of batch fermentation biogas fermentation three repeated analysis showed that the rich diversity of bacterial communities in biogas fermentation system. With the progress of fermentation, the absolute number of bacteria first increased and then stabilized; bacterial groups changed significantly, the longer the fermentation time, the greater the difference between the bacterial groups before and after fermentation; some bacteria groups always maintain the advantage of gas production rate , Methane content and temperature. Some bacterial groups were dominant during the specific fermentation period and correlated with the gas production rate and methane content. DGGE analysis at 84 days before fermentation showed that three replicate bacterial groups In particular, the changes of dominant groups are basically synchronous, but there are also some differences between similarities of 65% ~ 83%. Corresponding to the changes of bacterial groups, the gas production rates of three replicates and the changes of methane content were basically the same. During the 55 days before fermentation, the gas production on the 5th was between 2 and 8 L and the volume percentage of methane decreased from 65% to 30% ~ 45%. During 60 days to 100 days of fermentation, the gas production rate increased rapidly and reached a peak. At 5 days peak gas production reached 20 L, the methane volume percentage increased rapidly and peaked at 72% -75%. From the shorter fermentation period There are also significant differences in gas production rate and methane content between the three replicates, which corresponds to the existence of certain differences in bacterial taxa among the three replicates at the same time.