Environmental Biotechnology Lab, The University of Hong Kong SAR, Pokfulam Road, Hong Kong, China.
Microb Ecol. 2014 Aug;68(2):235-46. doi: 10.1007/s00248-014-0405-6. Epub 2014 Mar 16.
Methanogenesis from wastewater-borne organics and organic solid wastes (e.g., food residues) can be severely suppressed by the presence of toxic phenols. In this work, ambient (20 °C) and mesophilic (37 °C) methane-producing and phenol-degrading consortia were enriched and characterized using high-throughput sequencing (HTS). 454 Pyrosequencing indicated novel W22 (25.0 % of bacterial sequences) in the WWE1 and Sulfurovum-resembled species (32.0 %) in the family Campylobacterales were the most abundant in mesophilic and ambient reactors, respectively, which challenges previous knowledge that Syntrophorhabdus was the most predominant. Previous findings may underestimate bacterial diversity and low-abundance bacteria, but overestimate abundance of Syntrophorhabdus. Illumina HTS revealed that archaeal populations were doubled in ambient reactor and tripled in mesophilic reactor, respectively, compared to the ∼4.9 % (of the bacteria and archaea sequences) in the seed sludge. Moreover, unlike the dominance of Methanosarcina in seed sludge, acetotrophic Methanosaeta predominated both (71.4-76.5 % of archaeal sequences) ambient and mesophilic enrichments. Noteworthy, this study, for the first time, discovered the co-occurrence of green sulfur bacteria Chlorobia, sulfur-reducing Desulfovibrio, and Sulfurovum-resembling species under ambient condition, which could presumably establish mutualistic relationships to compete with syntrophic bacteria and methanogens, leading to the deterioration of methanogenic activity. Taken together, this HTS-based study unravels the high microbial diversity and complicated bacterial interactions within the biogas-producing and phenol-degrading bioreactors, and the identification of novel bacterial species and dominant methanogens involved in the phenol degradation provides novel insights into the operation of full-scale bioreactors for maximizing biogas generation.
废水中的有机物和有机固体废物（如食物残渣）的产甲烷作用会被有毒酚类物质严重抑制。在这项工作中，使用高通量测序（HTS）富集和表征了常温（20°C）和中温（37°C）产甲烷和苯酚降解生物群落。454 焦磷酸测序表明，在中温反应器和常温反应器中，W22（细菌序列的 25.0%）和硫还原菌科（Campylobacterales 家族）中类似于 Sulfurovum 的物种（32.0%）最为丰富，这挑战了之前认为 Syntrophorhabdus 是最主要的观点。先前的发现可能低估了细菌的多样性和低丰度细菌，但高估了 Syntrophorhabdus 的丰度。Illumina HTS 显示，与接种污泥中的约 4.9%（细菌和古菌序列）相比，常温反应器中的古菌种群增加了一倍，中温反应器中的古菌种群增加了两倍。此外，与接种污泥中 Methanosarcina 的优势不同，乙酸营养型 Methanosaeta 在常温和中温富集物中均占主导地位（古菌序列的 71.4-76.5%）。值得注意的是，这项研究首次发现了绿硫细菌 Chlorobia、硫还原菌 Desulfovibrio 和类似于 Sulfurovum 的物种在常温条件下共存，它们可能建立互利关系，与产甲烷菌和同型菌竞争，导致产甲烷活性恶化。总之，这项基于 HTS 的研究揭示了沼气生产和苯酚降解生物反应器中微生物的高度多样性和复杂的细菌相互作用，以及鉴定出的新型细菌物种和参与苯酚降解的优势产甲烷菌为优化全规模生物反应器以最大程度地提高沼气产量提供了新的见解。
