玉米秆与猪粪混合发酵产沼气及其古菌解析

Biogas production and Archaea composition in the co-fermentation biogas system of corn stalks and pig manure

为了解混合发酵系统不同发酵时间的古菌组成,采用批式全混发酵工艺进行预处理后的玉米秆和猪粪混合中温发酵产沼气研究,在不同发酵时间取样,利用454焦磷酸测序法测定各样品中古菌的组成.结果表明,该混合发酵启动迅速,第4天(d 4)达到产气高峰,料容产气率为1.46 L L-1 d-1,46 d原料产沼气率、产甲烷率分别为356.55 mL/g(VS)和208.0 mL/g(VS).454焦磷酸测序及分析表明,混合发酵系统中古菌都归属于广古菌门(Euryarchaeota,97.83%-100%)和泉古菌门(Crenarchae ota,0-2.17%);随着发酵时间的延长,甲烷杆菌纲(Methanobacteria)古菌含量由69.84%迅速下降到0.14%,杂色泉古菌(Miscellaneous Crenarchaeotic Group,MCG)和热原体纲(Thermoplasmata)古菌含量则分别由0%、1.05%逐渐上升到2.17%、20.68%,甲烷微菌纲(Methanomicrobia)古菌则从29.84%迅速上升到96.14%后保持高位.研究说明玉米秆和猪粪混合发酵可迅速启动,系统古菌多样性随发酵时间延长而逐渐上升.

In order to investigate the dynamics of Archaea community during co-fermentation, the mesophilic batch co- fermentation of pretreated cornstalks and pig manure was studied, with samples of different fermentation periods collected for community analysis using 454 pyrosequencing. The results showed very fast start-up of co-fermentation. The daily biogas production reached the maximum of 1.46 L L-~ d~ on 4＇h day. The biogas and methane yield was 356.55 mL/g VS and 208.0 mL/g VS respectively in 46 days. The 454 pyrosequencing analysis showed that the Archaea in the co-fermentation reactor belonged to Euryarchaeota （97.83%-100%） and Crenarehaeota （0%-2.17%）. With proceeding of fermentation, the content of Methanobacteria decreased rapidly from 69.84% to 0.14%, while the contents of Miscellaneous Crenarchaeotic Group and Thermoplasmata gradually increased from 0% and 1.05% to 2.17% and 20.68%, respectively. At the same time the content of Methanomicrobia sharply increased from 29.84% to 96.14% and remained at high level. It showed that co-fermentation of corn stalk and pig manure can quickly start up and the diversity of archaeal gradually increases during co-fermentation.