柠檬酸废水厌氧颗粒污泥微生物菌群结构解析

摘要

To clarify the performance of functional microorganisms involved in biological citric acid wastewater treatment systems, bacterial community structure of anaerobic granular sludge was investigated in an internal circulation ( IC) anaerobic reactor treating citric acid industry wastewater. Microstructure observation was carried out by environmental scanning electron microscope ( ESEM ) , and the microbial diversity and microfloras were analyzed by high⁃throughput sequencing. Particle size distribution results showed that the most particles’ diameters ranged from 1.0 mm to 4. 0 mm ( accounted for 74. 4%) . ESEM results showed that spherical bacteria were the dominant microorganisms in granular sludge. The total dataset comprised 8 397 high quality sequences, which could be subdivided into 873 operational taxonomic units. A library coverage of 0. 936 implied that the granular sludge exhibited a high microbial diversity and abundance. The Shannon index, ACE index and Chao1 index were 4.376, 3 415.51 and 2 246. 51, respectively. Genus classification revealed that there were four typical bacterial groups:hydrolytic fermentative bacteria for organic matter degradation were closely related to Paludibacter, Parabacteroides, Erysipelotrichaceae, Clostridium, Phascolarctobacterium, Aminobacterium, Saccharofermentans and Alkaliflexus, which accounted 24. 93% of the bulk bacterial; H2⁃producing and acetogenic bacteria were correlated with Petrimonas and Syntrophomonas, which accounted for 34. 89%; methanogens of Methanosaeta accounted 3. 44%;and the microflora groups of Levilinea, Longilinea and Thermovirga could be capable of tolerating toxic industrial wastewater, accounting for 14.62% instead.%为揭示柠檬酸废水生物处理过程中功能菌群作用机制，以柠檬酸工业废水内循环厌氧反应塔（ IC）中厌氧颗粒污泥为研究对象，统计颗粒粒径分布，通过环境扫描电子显微镜（ ESEM）观察颗粒微观形态结构，利用高通量测序技术分析微生物多样性及菌群特征．结果发现，粒径在1．0～4．0 mm的颗粒所占比例最多，为74．4％．ESEM显示微生物分布以球形细菌为主．高通量测序得到8397条有效序列，可划分操作分类单元（OTU）873个，Alpha多样性指数显示样品文库覆盖率0．936，Shannon指数为4．376，而ACE指数与Chao1指数分别为3415．51与2246．51，反映颗粒污泥中微生物种类与数量均较多．微生物菌群主要包括4大类，分别为可降解有机物的水解发酵菌群Paludibacter、Parabacteroides、Erysipelotrichaceae、Clostridium、Phascolarctobacterium、Aminobacterium、Saccharofermentans与Alkaliflexus（所占比例之和为24．93％）；产氢产乙酸菌群Petrimonas与Syntrophomonas（所占比例之和为34．89％）；产甲烷菌Methanosaeta（3．44％）及可耐受工业废水毒害的微生物菌群Levilinea、Longilinea与Thermovirga（所占比例之和为14．62％）．