School of Environment, Tsinghua University, 100084 Beijing, China.
School of Environment, Tsinghua University, 100084 Beijing, China.
Bioresour Technol. 2021 Jun;329:124899. doi: 10.1016/j.biortech.2021.124899. Epub 2021 Mar 2.
Chain elongation produce medium chain carboxylates, which are important precursors to many pharmaceuticals, antimicrobials and biofuels. Results in the presented investigations show that the supply of nano zero-valent iron (NZVI) can enhance caproate production. The highest caproate concentration achieved amounted to 27.2 mmol/L when 5 g/L NZVI were added, which was about 100% higher than the control. The study also showed increase of ethanol oxidation and decrease of butyrate and butanol with NZVI addition. Mechanism study showed NZVI can stimulate caproate production by preventing pH to fall below 5.4 through displacement reaction. Electron balance analysis displayed that NZVI provides extra electron by promoting ethanol oxidation and its dissolution. H was the potential electron shuttle between NZVI and chain elongators; High throughput sequencing showed function of NZVI on reshaping of microbial communities, especially enriching Oscillibacter Marseille-P3260, a kind of chain elongator and Corynebacterium which possesses fatty acid biosynthesis and iron utilization.
链延伸产生中链羧酸酯，它们是许多药物、抗菌剂和生物燃料的重要前体。本研究结果表明，纳米零价铁 (NZVI) 的供应可以提高己酸的产量。当添加 5 g/L 的 NZVI 时，己酸的最高浓度达到 27.2 mmol/L，比对照提高了约 100%。研究还表明，随着 NZVI 的添加，乙醇的氧化增加，而丁酸和丁醇减少。机理研究表明，NZVI 通过置换反应防止 pH 值下降到 5.4 以下，从而刺激己酸的产生。电子平衡分析表明，NZVI 通过促进乙醇氧化及其溶解来提供额外的电子。H 是 NZVI 和链延伸剂之间的潜在电子穿梭体；高通量测序显示，NZVI 对微生物群落的重塑具有作用，特别是富集了一种链延伸剂Oscillibacter Marseille-P3260 和一种具有脂肪酸生物合成和铁利用功能的棒状杆菌属。
