有机废弃物发酵液中氨氮对己酸巨球菌产酸性能的影响机制  

Effect of ammonia nitrogen on acid production performance in organic waste fermentation by Megasphaera hexanoica

作　　者：王泽宇 范红叶 刘灵秀 柏萌薇 陈浚 WANG Zeyu;FAN Hongye;LIU Lingxiu;BAI Mengwei;CHEN Jun(Zhejiang Provincial Key Laboratory of Pollution Exposure and Health Intervention,Interdisciplinary Research Academy,Zhejiang Shuren University,Hangzhou 310015;College of Biology and Environmental Engineering,Zhejiang Shuren University,Hangzhou 310015;College of Geography and Environmental Science,Zhejiang Normal University,Jinhua 321004;College of Environment,Zhejiang University of Technology,Hangzhou 310014)

机构地区：[1]浙江树人学院交叉科学研究院,浙江省污染暴露与健康干预重点实验室,杭州310015 [2]浙江树人学院生物与环境工程学院,杭州310015 [3]浙江师范大学地理与环境科学学院,金华321004 [4]浙江工业大学环境学院,杭州310014

出　　处：《环境科学学报》2024年第4期198-205,共8页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.42207161,42177115);浙江省自然科学基金(No.LTGS23D030001);浙江省教育厅一般科研项目(No.Y202147579);浙江树人学院科研成果奖培育项目(No.2023XZ037)。

摘　　要：如今,有机废弃物在厌氧发酵方面引起了极大的关注,然而形成的发酵液中不可避免地会导致氨氮(NH_(4)^(+)-N)积累,这对于碳延长微生物厌氧生产高附加值产物的工艺来说是一个未知的挑战.因此本文探究了不同浓度的NH_(4)^(+)-N对Megasphaera hexanoica(己酸巨球菌)厌氧发酵过程中代谢活性和己酸生产性能的影响.结果表明,低浓度(5 g·L^(-1))的NH_(4)^(+)-N诱导了菌株的最大己酸产量从41 mmol·L^(-1)增加至55 mmol·L^(-1),生物量也从800.15 mg·L^(-1)提升至992.74 mg·L^(-1).不仅如此,低浓度的NH_(4)^(+)-N促进了胞外聚合物的分泌,其中与电子转移相关的蛋白分泌量从81 mg·L^(-1)增加至117 mg·L^(-1),电子传递系统活性也从0.19 mg·g·min^(-1)提升至0.45 mg·g·min^(-1).最后,基因表达水平的结果显示低浓度的NH_(4)^(+)-N促进了与己酸合成、氨同化关键功能基因的表达,其中,1、3和5 g·L^(-1)的NH_(4)^(+)-N分别提升了菌株glt D功能基因表达水平的116%、124%和128%.本研究为发酵液中NH_(4)^(+)-N在厌氧发酵生物合成方面的影响机制及治理策略提供了一定的技术参考.Nowadays,anaerobic fermentation of organic wastes gained a wide attention,however,the fermentation broth inevitably leads to the accumulation of ammonia nitrogen(NH_(4)^(+)-N),which is an unknown challenge for carbon chain elongation microorganisms producing high value-added products.Therefore,this study investigated the effect of NH_(4)^(+)-N concentration on the metabolic activity and caproic acid production performance during anaerobic fermentation of Megasphaera hexanoica.The results showed that low concentration(5 g·L^(-1)) of NH_(4)^(+)-N induced an increase in the maximum caproic acid production from 41 to 55 mmol·L^(-1) and the biomass from 800.15 to 992.74 mg·L^(-1).In addition,the low concentration of NH_(4)^(+)-N facilitated the secretion of extracellular polymers,in which electron transfer related proteins increased from 81 to 117 mg·L^(-1),and the activity of the electron transport system was also elevated from 0.19 to 0.45 mg·g·min^(-1).Finally,the results of gene expression levels revealed that low concentrations of NH_(4)^(+)-N promoted the expression of key functional genes related to caproic acid synthesis and ammonia assimilation,where 1,3,and 5 g·L^(-1) of NH_(4)^(+)-Nelevated the expression levels of glt D functional genes by 116%,124%,and 128%,respectively.This study provides technical references for the influencing mechanism and management strategy of NH_(4)^(+)-N in anaerobic fermentation biosynthesis.

关 键 词：氨氮 碳延长 氨同化 己酸 胞外聚合物 

分 类 号：X705[环境科学与工程—环境工程] X172