Anhui Province Key Lab of Farmland Ecological Conservation and Pollution Prevention, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, PR China.
Anhui Province Key Lab of Farmland Ecological Conservation and Pollution Prevention, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, PR China.
J Hazard Mater. 2024 Oct 5;478:135362. doi: 10.1016/j.jhazmat.2024.135362. Epub 2024 Jul 28.
Although the anaerobic reduction of azo dyes is ecofriendly, high ammonia consumption remains a significant challenge. This work enriched a mixed nitrogen-fixing bacteria consortium (NFBC) using n-FeO to promote the anaerobic reduction of methyl orange (MO) without exogenous nitrogen. The enriched NFBC was dominated by Klebsiella (80.77 %) and Clostridium (17.16 %), and achieved a 92.7 % reduction of MO with an initial concentration of 25 mg·L. Compared with the control, the consortium increased the reduction efficiency of MO, cytochrome c content, and electron transport system (ETS) activity by 11.86 %, 89.86 %, and 58.49 %, respectively. When using 2.5 g·L n-FeO, the extracellular polymeric substances (EPS) of NFBC were present in a concentration of 85.35 mg·g. The specific reduction rates of MO by NFBC were 2.26 and 3.30 times faster than those of Fe(II) and Fe(III), respectively, while the enrichment factor of the ribosome pathway in NFBC exceeded 0.75. Transcriptome, carbon consumption, and EPS analyses suggested that n-FeO stimulated carbon metabolism and secreted protein synthesized by the mixed culture. The latter occurred due to the increased activity of consortium and the content of redox substances. These findings demonstrate that n-FeO promoted the efficiency of mixed nitrogen-fixing bacteria for removing azo dyes from wastewater. This innovative approach highlights the potential of integrating nanomaterials with biological systems to effectively address complex pollution challenges.
虽然偶氮染料的厌氧还原方法具有环保性，但高氨耗仍然是一个重大挑战。本研究使用 n-FeO 富集混合固氮菌（NFBC），在无需外加氮源的条件下促进甲基橙（MO）的厌氧还原。富集的 NFBC 以克雷伯氏菌（80.77%）和梭菌（17.16%）为主导，在初始浓度为 25mg·L 的条件下实现了 92.7%的 MO 还原。与对照组相比，该菌剂提高了 MO 的还原效率、细胞色素 c 含量和电子传递系统（ETS）活性，分别增加了 11.86%、89.86%和 58.49%。当使用 2.5g·L n-FeO 时，NFBC 的胞外聚合物（EPS）浓度达到 85.35mg·g。NFBC 对 MO 的比还原速率分别是 Fe(II)和 Fe(III)的 2.26 倍和 3.30 倍，而 NFBC 中核糖体途径的富集因子超过 0.75。转录组、碳消耗和 EPS 分析表明，n-FeO 刺激了混合培养物的碳代谢和分泌蛋白的合成。这是由于菌剂活性的增加和氧化还原物质含量的增加所致。这些发现表明，n-FeO 提高了混合固氮菌去除废水中偶氮染料的效率。这种创新方法突出了将纳米材料与生物系统相结合以有效应对复杂污染挑战的潜力。
