文献类型：期刊文献

中文题名：耐盐异养硝化-好氧反硝化细菌Enterobacter kobei JM的脱氮特性及全基因组分析

英文题名：Denitrification performance and whole genome analysis of a salttolerant heterotrophic nitrifying-aerobic denitrifying bacterial strain Enterobacter kobei JM

作者：李旭[1,2];尹鹏[2,3];刘凤坤[1,2];许敬轩[1,2];郑雅之[1,2];赵吉臣[2];郭慧[1];戴睿智[3];廖劲松[3];黄文[1,2,3]

机构：[1]广东海洋大学水产学院湛江市海洋生态与养殖环境重点实验室,广东湛江524088;[2]广东省农业科学院动物科学研究所、广东省畜禽育种与营养研究重点实验室农业农村部华南动物营养与饲料重点实验室、广东省农业科学院水产研究中心,广东广州510640;[3]广东益康生态环境科技集团有限公司,广东云浮510665

年份：2026

卷号：53

期号：5

起止页码：2269

中文期刊名：微生物学通报

外文期刊名：Microbiology China

收录：北大核心2023、、北大核心

基金：广东省农业科学院人才项目(R2020YJ-QG001,R2022PY-QY008);广东省农业科学院协同创新中心项目(202137,202138,XT202231);云浮市科技局人才发展战略专项资金项目(YF2025NYRC04)。

语种：中文

中文关键词：神户肠杆菌;异养硝化-好氧反硝化;耐盐机制;脱氮特性;全基因组

外文关键词：Enterobacter kobei;heterotrophic nitrifying-aerobic denitrifying;salt tolerance mechanism;nitrogen removal characteristic;whole genome

中文摘要：【背景】异养硝化-好氧反硝化(heterotrophic nitrifying-aerobic denitrifying,HN-AD)菌株在水产养殖尾水脱氮中应用潜力巨大,但多数菌株存在严重的盐抑制效应,并且其耐盐分子机制缺乏系统性解析,极大地限制了其在咸淡水及海水养殖尾水处理中的应用。【目的】分离鉴定一株耐盐异养硝化-好氧反硝化细菌,旨在开发高效脱氮菌种并推动高盐养殖废水脱氮技术研究。【方法】从水产养殖尾水处理系统生物膜中分离筛选高效HN-AD菌株,通过形态学、生理生化特征及全基因组测序进行鉴定;通过药敏试验和斑马鱼攻毒实验评估其生物安全性;优化其脱氮条件(碳源、C/N、pH、温度、盐度);利用单一氮源实验验证其硝化与反硝化能力;结合全基因组测序与RT-qPCR技术阐释其脱氮与耐盐分子机制。【结果】菌株JM被鉴定为神户肠杆菌(Enterobacter kobei),对多种抗生素敏感并有良好的生物安全性,最适脱氮条件为:葡萄糖为碳源、C/N 10、pH 7.0、温度30℃、总氮(total nitrogen,TN)、氨氮(NH4+-N)、亚硝酸盐氮(NO2--N)和硝酸盐氮(NO3--N)去除率可分别达到93.90%、92.23%、100.00%和92.63%。在0%-5.0%的盐度下能正常生长且3.0%的盐度下同样保持良好的脱氮能力(TN去除率85.66%)。全基因组分析显示,菌株JM具有多种脱氮关键基因,推测脱氮途径以氮同化为主导;同时具有胞内小分子相容性物质积累及K+转运相关基因,表明菌株JM可通过积累胞内小分子和维持渗透压来抵抗盐碱胁迫。在处理混合氮源时,菌株JM优先同化NH4+-N。RT-qPCR结果表明,硝酸盐还原酶基因(nas,nar)及亚硝酸盐还原酶基因(nirB)的表达显著上调,推测该菌株具有以氮同化为主的脱氮特性。【结论】菌株JM是一株耐盐、安全且高效的异养硝化-好氧反硝化细菌,在高盐养殖废水处理中展现出重要的应用潜力。

外文摘要：[Background]Heterotrophic nitrifying-aerobic denitrifying(HN-AD)strains show great potential for nitrogen removal in aquaculture wastewater.However,most reported strains exhibit significantly reduced efficiency under high-salinity conditions,and their molecular salt-tolerance mechanisms remain poorly understood,which greatly limit their application in brackish and marine aquaculture wastewater treatment.[Objective]To isolate and characterize a salt-tolerant HN-AD bacterium for potential use in high-salinity wastewater treatment.[Methods]We isolated a highly efficient HN-AD strain from the biofilm samples obtained from an aquaculture wastewater treatment system.The strain was identified based on morphological,physiological,and biochemical characteristics and whole genome sequencing.We conducted antibiotic susceptibility tests and zebrafish toxicity assays to evaluate the biosafety of the strain.We then optimized the nitrogen removal conditions,including carbon source,carbon-to-nitrogen(C/N)ratio,pH,temperature,and salinity,and assessed the nitrification and denitrification capabilities via single nitrogen source experiments.Furthermore,we elucidated the molecular mechanisms of nitrogen removal and salt tolerance through whole genome sequencing and RT-qPCR.[Results]The isolated strain JM was identified as Enterobacter kobei.It showed high antibiotic sensitivity and biosafety.Under optimal conditions(glucose as the carbon source,C/N ratio=10,pH 7.0,and 30℃),it achieved the removal rates of 93.90%for total nitrogen(TN),92.23%for NH4+-N,100.00%for NO2?-N,and 92.63%for NO3?-N.It maintained normal growth at the salinity of 0%to 5.0%and 85.66%TN removal at the salinity of 3.0%.Whole genome sequencing revealed that strain JM carried multiple key genes for nitrogen removal,suggesting that the nitrogen removal pathway was dominated by nitrogen assimilation.Moreover,the strain carried the genes associated with intracellular accumulation of small molecule compatible substances and K+transport,which indicated that strain JM can respond to saline-alkali stress by accumulating intracellular small molecules and maintaining osmotic pressure.When dealing with mixed nitrogen sources,strain JM prioritized the assimilation of NH4+-N.RT-qPCR results showed significantly upregulated expression of the nitrate reductase genes nas and nar and the nitrite reductase gene nirB,suggesting nitrogen assimilation as the primary nitrogen removal pathway adopted by this strain.[Conclusion]Our findings indicate that E.kobei JM is a salt-tolerant,safe,and highly efficient HN-AD bacterium with significant potential for treating high-salinity aquaculture wastewater.