一株1,4-二噁烷降解菌的分离及其降解性能解析  

Isolation and degradation characterization of a 1,4-dioxane-degrading bacterial strain

作　　者：张玥 赵联芳[1] 田坤 江煜 马瑞 刘云[2,3] ZHANG Yue;ZHAO Lianfang;TIAN Kun;JIANG Yu;MA Rui;LIU Yun(College of Environment,Hohai University,Nanjing 210098,Jiangsu,China;State Key Laboratory of Soil&Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,Jiangsu,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]河海大学环境学院,江苏南京210098 [2]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,江苏南京210008 [3]中国科学院大学,北京100049

出　　处：《生物工程学报》2024年第10期3722-3749,共28页Chinese Journal of Biotechnology

基　　金：国家自然科学基金(41877504);江苏省碳达峰碳中和科技创新专项(BK20220004)。

摘　　要：为应对水环境中潜在致癌物质1,4-二噁烷(1,4-dioxane)的污染,本研究从1,4-二噁烷污染的地下水中,通过富集驯化、分离得到一株1,4-二噁烷高效降解菌株DXTK-010。经过形态学观察、16S rRNA基因序列比对以及基于全基因组的物种分类研究,鉴定该菌株为觧胺胺杆菌(Aminobacter aminovorans)。研究结果表明,该菌株具有较强的环境适应能力,在20-37℃及pH5.0-8.0下均能有效降解1,4-二噁烷。单因素实验表明,在30℃、pH 7.5条件下降解性能最佳。在优选条件下,该菌株能在24 h内完全降解200 mg/L的1,4-二噁烷,最大降解速率达9.367 mg/(L·h)。菌株DXTK-010对1,4-二噁烷的降解动力学采用Monod方程进行拟合,其最大比降解速率(V_(max))为0.224 mg 1,4-dioxane/(mg protein·h),半饱和浓度(K_(s))为41.350 mg/L,细胞产率(Y)为0.130 mg protein/(mg 1,4-dioxane),与已报道的降解菌相比,DXTK-010作为优异的降解菌株,扩充了生物修复1,4-二噁烷的菌株资源。全基因组测序揭示其完整基因组包括1条环状染色体和3个质粒。功能基因分析表明,丙烷单加氧酶基因簇和醇脱氢酶基因是其高效降解1,4-二噁烷的关键功能基因。本研究为DXTK-010实际应用于1,4-二噁烷污染修复提供了理论基础。To address the potential pollution caused by the carcinogen 1,4-dioxane in aquatic environments,we isolated a highly efficient 1,4-dioxane-degrading bacterial strain,designated as DXTK-010,from the groundwater contaminated by 1,4-dioxane.According to the morphological characteristics,the phylogenetic tree established based on the 16S rRNA gene sequence,and the whole genome sequence,we identified DXTK-010 as Aminobacter aminovorans.This strain demonstrated robust degradation capacity within a temperature range of 20℃to 37℃and a pH range of 5.0 to 8.0.Furthermore,single-factor experiments indicated the optimal degradation conditions at 30℃and pH 7.5.Under the optimal conditions,the strain completely degraded 200 mg/L of 1,4-dioxane within 24 h,achieving a maximum degradation rate of 9.367 mg/(L·h).The Monod equation was adopted to fit the degradation kinetics of 1,4-dioxane at different initial concentrations,which revealed a maximum specific degradation rate of 0.224 mg 1,4-dioxane/(mg protein·h),a half-saturation constant(K_(s))of 41.350 mg/L,and a cell yield of 0.130 mg protein/(mg 1,4-dioxane).Whole genome sequencing revealed a circular chromosome and three plasmids within DXTK-010.Functional gene annotation and analysis underscored the significance of the propane monooxygenase gene cluster and alcohol dehydrogenase gene in facilitating the efficient degradation of 1,4-dioxane by this strain.DXTK-010 outperformed the existing degraders for 1,4-dioxane,expanding the strain resources for the bioremediation of 1,4-dioxane pollution.This study provides a theoretical basis for the practical application of DXTK-010 in the remediation of 1,4-dioxane pollution.

关 键 词：1 4-二噁烷 觧胺胺杆菌(Aminobacter aminovorans) 单因素实验 降解动力学 全基因组测序 

分 类 号：X172[环境科学与工程—环境科学]