Ning Zhifang, Dou Di, Liu Jiale, Qin Xue, Huang Yali, Yang Tianqi, Zhang Jiaxing
College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China.
College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China; Pollution Prevention Biotechnology Laboratory of Hebei Province, Shijiazhuang 050018, China.
Bioresour Technol. 2025 Oct;434:132776. doi: 10.1016/j.biortech.2025.132776. Epub 2025 Jun 5.
Efficient synthesis of caproate is crucial for the recovery of organic wastes. However, the yield and selectivity of caproate are limited by the efficiency of carbon chain elongation (CCE). This study presents sulfur-modified carbon-iron composites (BC[S-Fe]) as an innovative approach to enhance CCE for efficient caproate biosynthesis. Unlike conventional carbon-iron materials (BC[Fe]), sulfur modification stabilized nano-zero-valent iron (Fe) against oxidation and amplified redox activity, achieving an 83 % higher caproate yield (6914 mg·L) and 58 % carbon conversion efficiency. BC[S-Fe ] (S:Fe = 1:5) outperformed BC, Fe and BC[Fe] by enriching electroactive bacteria (e.g., Rummeliibacillus suwonensis, Seramator thermalis, and Rubeoparvulum massiliense) that upregulated electron transfer genes and CCE metabolic genes. Additionally, BC[S-Fe ] enhanced biofilm formation and quorum sensing, fostering microbial synergy to optimize electron flux. This work pioneers the integration of sulfur-modified composites into microbial CCE systems, offering a novel strategy to optimize caproate synthesis through enhanced electron transfer and functional microbiome engineering.
己酸盐的高效合成对于有机废物的回收至关重要。然而，己酸盐的产量和选择性受到碳链延长（CCE）效率的限制。本研究提出了硫改性碳铁复合材料（BC[S-Fe]），作为一种创新方法来增强CCE以实现高效的己酸盐生物合成。与传统的碳铁材料（BC[Fe]）不同，硫改性可稳定纳米零价铁（Fe）防止氧化并放大氧化还原活性，己酸盐产量提高83%（6914 mg·L），碳转化效率提高58%。BC[S-Fe]（S:Fe = 1:5）通过富集上调电子传递基因和CCE代谢基因的电活性细菌（如Suwonensis瘤胃杆菌、热血清杆菌和马赛鲁伯氏小杆菌），其性能优于BC、Fe和BC[Fe]。此外，BC[S-Fe]增强了生物膜形成和群体感应，促进了微生物协同作用以优化电子通量。这项工作开创了将硫改性复合材料整合到微生物CCE系统中的先河，提供了一种通过增强电子传递和功能性微生物组工程来优化己酸盐合成的新策略。
