For better understanding the role of magnetite in methanation of different substrates, two up-flow anaerobic sludge bed reactors (RM with magnetite; RS with silica) were built using acetate (stage I), propionate + butyrate (stage II), and sucrose (stage III) as the substrates, respectively. RM reactor showed better COD removal efficiency and adaptability to different substrate impacts. More extracellular polymeric substances (EPS) were produced for anaerobic sludge granulation, and the sludge in RM had better intensity, hydrophobicity and electroactivity compared with those in RS. Interestingly, magnetite had different promoting effects on methanogenic degradation of different substrates, and magnetite facilitated different syntrophic partners, like Desulfovibrio, Smithella, unidentified Clostridiates and Methanosaeta in different stages. The strengthening factor of biogas production from sucrose was the highest (1.23 ± 0.03), and analysis of key enzyme activities indicated that the potential magnetite-induced direct interspecies electron transfer (DIET) improved the process between the glycolysis, oxidation of pyruvate and CO₂-dependent methanogenesis.

为了更好地了解磁铁矿在不同基质甲烷化中的作用，使用乙酸盐（阶段I），丙酸酯+丁酸盐（阶段II）和蔗糖（两个阶段）构建了两个上流厌氧污泥床反应器（RM与磁铁矿； RS与二氧化硅）阶段III）分别作为基材。RM反应器显示出更好的COD去除效率和对不同底物影响的适应性。厌氧污泥颗粒化产生了更多的细胞外聚合物（EPS），与RS相比，RM中的污泥具有更好的强度，疏水性和电活性。有趣的是，磁铁矿对不同基质甲烷化降解的促进作用不同，磁铁矿促进了不同的同养伴侣，如Desulfovibrio，Smithella，未鉴定的梭菌和甲烷菌处于不同阶段。蔗糖生产沼气的强化因子最高（1.23±0.03），对关键酶活性的分析表明，潜在的磁铁矿诱导的直接种间电子转移（DIET）改善了糖酵解，丙酮酸氧化和CO ₂之间的过程。依赖的甲烷生成。