Advanced Water Management Centre-AWMC, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia.
Syst Appl Microbiol. 2013 Jun;36(4):281-90. doi: 10.1016/j.syapm.2013.03.003. Epub 2013 May 1.
Thermophilic biological pre-treatment enables enhanced anaerobic digestion for treatment of wastewater sludges but, at present, there is limited understanding of the hydrolytic-acidogenic microbial composition and its contribution to this process. In this study, the process was assessed by comparing the microbiology of thermophilic (50-65 °C) and mesophilic (35 °C) pre-treatment reactors treating primary sludge. A full-cycle approach for the 16S rRNA genes was applied in order to monitor the diversity of bacteria and their abundance in a thermophilic pre-treatment reactor treating primary sludge. For the thermophilic pre-treatment (TP), over 90% of the sequences were previously undetected and these had less than 97% sequence similarity to cultured organisms. During the first 83 days, members of the Betaproteobacteria dominated the community sequences and a newly designed probe was used to monitor a previously unknown bacterium affiliated with the genus Brachymonas. Between days 85 and 183, three phylotypes that affiliated with the genera Comamonas, Clostridium and Lysobacter were persistently dominant in the TP community, as revealed by terminal-restriction fragment length polymorphism (T-RFLP). Hydrolytic and fermentative functions have been speculated for these bacteria. Mesophilic pre-treatment (MP) and TP communities were different but they were both relatively dynamic. Statistical correlation analysis and the function of closely allied reference organisms indicated that previously unclassified bacteria dominated the TP community and may have been functionally involved in the enhanced hydrolytic performance of thermophilic anaerobic pre-treatment. This study is the first to reveal the diversity and dynamics of bacteria during anaerobic digestion of primary sludge.
嗜热生物预处理能够增强厌氧消化处理废水污泥的能力，但目前对于水解产酸微生物的组成及其对该过程的贡献了解有限。在这项研究中，通过比较处理初沉污泥的高温（50-65°C）和中温（35°C）预处理反应器的微生物学，评估了该过程。采用了 16S rRNA 基因的全循环方法，以监测处理初沉污泥的高温预处理反应器中细菌的多样性及其丰度。对于高温预处理（TP），超过 90%的序列以前未被检测到，这些序列与培养的生物的相似度低于 97%。在最初的 83 天内，β变形菌门的成员主导了群落序列，并且使用新设计的探针来监测先前未知的与短柄菌属相关的细菌。在第 85 天到 183 天之间，通过末端限制性片段长度多态性（T-RFLP）揭示，与贪噬菌属、梭菌属和节杆菌属相关的三个类群在 TP 群落中持续占优势。这些细菌的水解和发酵功能已被推测出来。中温预处理（MP）和 TP 群落不同，但都相对动态。统计相关性分析和密切相关的参考生物的功能表明，以前未分类的细菌主导了 TP 群落，并且可能在高温厌氧预处理的增强水解性能中具有功能作用。这项研究首次揭示了初沉污泥厌氧消化过程中细菌的多样性和动态。
