Chain Elongation Using Native Soil Inocula:Exceptional n-Caproate Biosynthesis Performance and Microbial Mechanisms  

原生土壤的碳链延长过程——高效的正己酸生物合成性能及微生物机制

作　　者：Lin Deng Yang Lv Tian Lan Qing-Lian Wu Wei-Tong Ren Hua-Zhe Wang Bing-Jie Ni Wan-Qian Guo 邓琳;吕杨;蓝天;吴清莲;任韦同;王华哲;倪丙杰;郭婉茜

机构地区：[1]State Key Laboratory of Urban Water Resource and the Environment,Harbin Institute of Technology,Harbin 150090,China [2]Centre for Technology in Water and Wastewater&School of Civil and Environmental Engineering,University of Technology Sydney,Sydney,NSW 2007,Australia

出　　处：《Engineering》2024年第8期262-272,共11页工程（英文）

基　　金：supported by the National Natural Science Foundation of China(52000132 and 51978201);Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(HC202241);the Fundamental Research Funds for the Central Universities.

摘　　要：This study demonstrates the feasibility and effectiveness of utilizing native soils as a resource for inocula to produce n-caproate through the chain elongation(CE)platform,offering new insights into anaerobic soil processes.The results reveal that all five of the tested soil types exhibit CE activity when supplied with high concentrations of ethanol and acetate,highlighting the suitability of soil as an ideal source for n-caproate production.Compared with anaerobic sludge and pit mud,the native soil CE system exhibited higher selectivity(60.53%),specificity(82.32%),carbon distribution(60.00%),electron transfer efficiency(165.00%),and conductivity(0.59 ms∙cm^(-1)).Kinetic analysis further confirmed the superiority of soil in terms of a shorter lag time and higher yield.A microbial community analysis indicated a positive correlation between the relative abundances of Pseudomonas,Azotobacter,and Clostridium and n-caproate production.Moreover,metagenomics analysis revealed a higher abundance of functional genes in key microbial species,providing direct insights into the pathways involved in n-caproate formation,including in situ CO_(2)utilization,ethanol oxidation,fatty acid biosynthesis(FAB),and reverse beta-oxidation(RBO).The numerous functions in FAB and RBO are primarily associated with Pseudomonas,Clostridium,Rhodococcus,Stenotrophomonas,and Geobacter,suggesting that these genera may play roles that are involved or associated with the CE process.Overall,this innovative inoculation strategy offers an efficient microbial source for n-caproate production,underscoring the importance of considering CE activity in anaerobic soil microbial ecology and holding potential for significant economic and environmental benefits through soil consortia exploration.

关 键 词：SOIL Chain elongation n-caproate Reverse beta-oxidation Fatty acid biosynthesis METAGENOMICS 

分 类 号：TQ225.125[化学工程—有机化工]