Joint Genome Institute, Lawrence National Berkeley Laboratory, Walnut Creek, CA, USA.
ISME J. 2011 Jan;5(1):122-30. doi: 10.1038/ismej.2010.125. Epub 2010 Aug 5.
Terephthalate (TA) is one of the top 50 chemicals produced worldwide. Its production results in a TA-containing wastewater that is treated by anaerobic processes through a poorly understood methanogenic syntrophy. Using metagenomics, we characterized the methanogenic consortium inside a hyper-mesophilic (that is, between mesophilic and thermophilic), TA-degrading bioreactor. We identified genes belonging to dominant Pelotomaculum species presumably involved in TA degradation through decarboxylation, dearomatization, and modified β-oxidation to H(2)/CO(2) and acetate. These intermediates are converted to CH(4)/CO(2) by three novel hyper-mesophilic methanogens. Additional secondary syntrophic interactions were predicted in Thermotogae, Syntrophus and candidate phyla OP5 and WWE1 populations. The OP5 encodes genes capable of anaerobic autotrophic butyrate production and Thermotogae, Syntrophus and WWE1 have the genetic potential to oxidize butyrate to CO(2)/H(2) and acetate. These observations suggest that the TA-degrading consortium consists of additional syntrophic interactions beyond the standard H(2)-producing syntroph-methanogen partnership that may serve to improve community stability.
对苯二甲酸（TA）是全球产量排名前 50 的化学物质之一。其生产过程会产生含有 TA 的废水，这些废水通过厌氧工艺进行处理，其中涉及一种甲烷生成菌的共生作用，但人们对此了解甚少。本研究采用宏基因组学方法，对嗜高温（即中温与高温之间）、可降解 TA 的生物反应器内的产甲烷菌群进行了特征描述。研究人员鉴定出了属于 Pelotomaculum 优势种的基因，这些基因可能通过脱羧作用、去芳构化作用以及经改良的β-氧化作用将 TA 降解为 H(2)/CO(2)和乙酸盐。三种新型嗜中温产甲烷菌可将这些中间体进一步转化为 CH(4)/CO(2)。Thermotogae、Syntrophus 和候选门 OP5 和 WWE1 种群中还预测存在其他次级共生相互作用。OP5 编码能够进行厌氧自养丁酸生产的基因，Thermotogae、Syntrophus 和 WWE1 具有将丁酸氧化为 CO(2)/H(2)和乙酸盐的遗传潜力。这些观察结果表明，TA 降解菌群除了标准的产 H(2)产甲烷菌共生关系外，还存在其他共生相互作用，这可能有助于提高群落稳定性。
