School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China; School of Life Science and Bioengineering, Henan University of Urban Construction, Pingdingshan 467036, China.
School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China; Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region, Jiaozuo 454000, China.
Sci Total Environ. 2024 Oct 10;946:174085. doi: 10.1016/j.scitotenv.2024.174085. Epub 2024 Jun 21.
Coalbed methane (CBM) presents a promising energy source for addressing global energy shortages. Nonetheless, challenges such as low gas production from individual wells and difficulties in breaking gels at low temperatures during extraction hinder its efficient utilization. Addressing this, we explored native microorganisms within coal seams to degrade guar gum, thereby enhancing CBM production. However, the underlying mechanisms of biogenic methane production by synergistic biodegradation of lignite and guar gum remain unclear. Research results showed that the combined effect of lignite and guar gum enhanced the production, yield rate and concentration of biomethane. When the added guar gum content was 0.8 % (w/w), methane production of lignite and guar gum reached its maximum at 561.9 mL, which was 11.8 times that of single lignite (47.3 mL). Additionally, guar gum addition provided aromatic and tryptophan proteins and promoted the effective utilization of CC/CH and OCO groups on the coal surface. Moreover, the cooperation of lignite and guar gum accelerated the transformation of volatile fatty acids into methane and mitigated volatile fatty acid inhibition. Dominant bacteria such as Sphaerochaeta, Macellibacteroides and Petrimonas improved the efficiency of hydrolysis and acidification. Electroactive microorganisms such as Sphaerochaeta and Methanobacterium have been selectively enriched, enabling the establishment of direct interspecies electron transfer pathways. This study offers valuable insights for increasing the production of biogenic CBM and advancing the engineering application of microbial degradation of guar gum fracturing fluid. Future research will focus on exploring the methanogenic capabilities of lignite and guar gum in in-situ environments, as well as elucidating the specific metabolic pathways involved in their co-degradation.
煤层气（CBM）作为一种有前途的能源，为解决全球能源短缺问题提供了可能。然而，个别井产气量低和开采过程中低温下凝胶破裂困难等挑战，阻碍了其有效利用。针对这些问题，我们探索了煤层中的土著微生物来降解胍胶，从而提高 CBM 的产量。然而，褐煤和胍胶协同生物降解产生生物甲烷的潜在机制尚不清楚。研究结果表明，褐煤和胍胶的共同作用增强了生物甲烷的产量、产率和浓度。当添加的胍胶含量为 0.8%（w/w）时，褐煤和胍胶的甲烷产量达到最大值，为 561.9 mL，是单一褐煤（47.3 mL）的 11.8 倍。此外，胍胶的添加提供了芳香族和色氨酸蛋白，并促进了煤表面上 CC/CH 和 OCO 基团的有效利用。此外，褐煤和胍胶的协同作用加速了挥发性脂肪酸向甲烷的转化，并减轻了挥发性脂肪酸的抑制作用。优势细菌如 Sphaerochaeta、Macellibacteroides 和 Petrimonas 提高了水解和酸化的效率。电活性微生物如 Sphaerochaeta 和 Methanobacterium 已被选择性富集，从而建立了直接的种间电子转移途径。本研究为提高生物成因 CBM 的产量和推进微生物降解胍胶压裂液的工程应用提供了有价值的见解。未来的研究将集中于探索褐煤和胍胶在原位环境中的产甲烷能力，并阐明它们共降解的具体代谢途径。
