芦岭煤田微生物群落结构和生物成因气的产甲烷类型研究

Microbial community and the type of methanogenesis associated with biogenic gas in Luling Coalfield, China

摘要:

[目的]揭示芦岭煤田微生物群落组成，并分析其潜在的产甲烷类型及产甲烷途径。[方法]采集芦岭煤田的煤层气样品和产出水样品，分别分析样品的地球化学性质特征；利用Illumina HiSeq高通量测序技术分析产出水中的微生物群落结构；采用添加不同底物的厌氧培养实验进一步证实芦岭煤田生物成因气的产甲烷类型。[结果]该地区煤层气为生物成因和热成因的混合成因气；古菌16S rRNA基因分析表明在产出水中含有乙酸营养型、氢营养型和甲基营养型的产甲烷菌。丰度较高的细菌具有降解煤中芳香族和纤维素衍生化合物的潜力。厌氧富集培养结果表明，添加乙酸盐、甲酸盐、H₂+CO₂为底物的矿井水样均有明显的甲烷产生。[结论]芦岭煤田具有丰富的生物多样性，该地区同时存在三种产甲烷类型。本研究为利用微生物技术提高煤层气的采收率，实现煤层气的可持续开采提供科学依据。

Abstract:

[Objective] The aim of this study was to study microbial community structures and type of methanogenesis associated with biogenic gas in Luling Coalfield, China. [Methods] We detected microbial distribution of the formation water by high-throughput pyrosequencing and bioinformatic analysis. Anaerobic culture was also used to verify the type of methanogenesis. [Results] The composition and stable isotopic ratios of gas samples implied a mixed biogenic and thermogenic methane. Archaeal 16S rRNA gene analysis revealed the survival of the acetoclastic, methylotrophic, and hydrogenotrophic methanogen in the produced water. Most detected bacteria could degrade aromatic and cellulose-derived compounds in coal. The activity and potential of methanogens of the related bacteria were confirmed by the obvious methane production in enrichments supplemented with acetate, formate or H₂+CO₂. [Conclusion] Acetoclastic and methylotrophic as well as hydrogenotrophic methanogenesis was responsible for the methanogenesis in Luling coalfield. These results would provide theoretical basis to improve the coal bed methane production using microbial technology and realize the sustainable exploitation of coal bed methane.