不同成熟度煤样产甲烷潜力

Methane-generating potential of coal samples with different maturity

【目的】评估不同类型煤炭生物降解转化为甲烷的潜力,研究原位煤层的微生物群落结构特征。【方法】分别在原位模拟、补加烃降解产甲烷菌系和补加碳源下厌氧培养煤样,利用气相色谱监测甲烷产生趋势,及高通量测序技术研究原位煤层的细菌和古菌群落。【结果】10个样品中有3个高成熟度煤样可以被厌氧降解转化为甲烷。通过生物强化和添加外源底物可以促进HF煤样的产甲烷潜力。其中SL煤样中的古菌类群主要是氢营养型产甲烷菌Methanoculleus和乙酸营养型产甲烷菌Methanosaeta为主,细菌类群主要属于Firmicutes(54.4%)、Proteobacteria(30.9%)、未培养微生物(10.8%)、Caldiserica(1.5%)及Thermotogae(1.3%)。【结论】不同成熟度煤样降解产气潜力不同,在部分原位煤层中可能存在参与烃降解与甲烷产生的功能菌。

[Objective] To evaluate coal bed methane production potential and characterize the in situ microbial communities of coal bed.[Methods] Coal samples were incubated under anaerobic conditions： mimicking coal bed condition,supplementing with methanogenic hydrocarbon degrading consortium,or adding with exogenetic substrate.Methane production was observed over time using gas chromatograph,and the in situ bacterial and archaeal communities were revealed using pyrosequencing.[Results]Enrichment incubation revealed that 3 of total 10 coal samples microcosms produced methane; bioaugmentation and substrate addition could enhance methane production of coal sample HF.Hydrogenotrophic Methanoculleus and acetoclastic Methanosaeta dominated the archaeal community of coal sample SL,while the bacterial domain was mainly composed of Firmicutes （54.4%）,Proteobacteria （30.9%）,uncultured bacteria （10.8%）,Caldiserica （1.5%） and Thermotogae （1.3%）.[Conclusion]The methane production potential of coal bed samples with different maturity is different; the in situ coal bed microcosms are likely involved in hydrocarbons degradation and methane production.