Hao Liping, Lü Fan, Wu Qing, Shao Liming, He Pinjing
State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China.
State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai, China; Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, China.
PLoS One. 2014 Mar 21;9(3):e92604. doi: 10.1371/journal.pone.0092604. eCollection 2014.
To precisely control the application of methyl fluoride (CH3F) for analysis of methanogenic pathways, the influence of 0-10% CH3F on bacterial and archaeal communities in a thermophilic methanogenic sludge was investigated. The results suggested that CH3F acts specifically on acetoclastic methanogenesis. The inhibitory effect stabilized at an initial concentration of 3-5%, with around 90% of the total methanogenic activity being suppressed, and a characteristic of hydrogenotrophic pathway in isotope fractionation was demonstrated under this condition. However, extended exposure (12 days) to high concentrations of CH3F (>3%) altered the bacterial community structure significantly, resulting in increased diversity and decreased evenness, which can be related to acetate oxidation and CH3F degradation. Bacterial clone library analysis showed that syntrophic acetate oxidizing bacteria Thermacetogenium phaeum were highly enriched under the suppression of 10% CH3F. However, the methanogenic community did not change obviously. Thus, excessive usage of CH3F over the long term can change the composition of the bacterial community. Therefore, data from studies involving the use of CH3F as an acetoclast inhibitor should be interpreted with care. Conversely, CH3F has been suggested as a factor to stimulate the enrichment of syntrophic acetate oxidizing bacteria.
为精确控制用于分析产甲烷途径的甲基氟（CH3F）的施加，研究了0-10% CH3F对嗜热产甲烷污泥中细菌和古菌群落的影响。结果表明，CH3F对乙酸裂解产甲烷作用具有特异性。抑制作用在初始浓度为3-5%时稳定下来，约90%的总产甲烷活性受到抑制，在此条件下证明了同位素分馏中氢营养途径的特征。然而，长时间暴露（12天）于高浓度CH3F（>3%）会显著改变细菌群落结构，导致多样性增加和均匀度降低，这可能与乙酸氧化和CH3F降解有关。细菌克隆文库分析表明，在10% CH3F的抑制作用下，互营乙酸氧化菌嗜热栖热菌高度富集。然而，产甲烷群落没有明显变化。因此，长期过量使用CH3F会改变细菌群落的组成。因此，涉及使用CH3F作为乙酸裂解抑制剂的研究数据应谨慎解读。相反，CH3F被认为是刺激互营乙酸氧化菌富集的一个因素。
