新型锰氧化菌株Pseudoxanthomonas mexicana S5-3_5X的分离及锰氧化机理研究  

Isolation and manganese oxidation mechanism of a novel MnⅡ-oxidizing strain Pseudoxanthomonas mexicana S5-3_5X

作　　者：李泽 王宇晗 梁金松 王爱杰 LI Ze;WANG Yuhan;LIANG Jinsong;WANG Aijie(School of Environment,Liaoning University,Shenyang 110000;School of Civil and Environmental Engineering,Harbin Institute of Technology(Shenzhen),Shenzhen 518055;State Key Laboratory of Urban Water Resource and Environment,School of Environment,Harbin Institute of Technology,Harbin 150090)

机构地区：[1]辽宁大学环境学院,沈阳110000 [2]哈尔滨工业大学(深圳)土木与环境工程学院,深圳518055 [3]哈尔滨工业大学环境学院城市水资源与水环境国家重点实验室,哈尔滨150090

出　　处：《环境科学学报》2022年第8期127-136,共10页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.52170156,31700106);深圳市科技计划资助项目(No.KQTD20190929172630447);深圳市高层次人才科研启动项目(No.FA11409008)。

摘　　要：锰氧化微生物能催化氧化Mn~Ⅱ生成锰氧化物(Mn),而生成的锰氧化物可强化水处理体系(如锰砂滤池、湿地)中的微量有机污染物降解及底泥中甲烷的厌氧氧化,因而受到广泛研究.从环境中分离出更多种属和生态位的锰氧化菌是生物强化环境中锰氧化过程的重要基础.依据锰氧化菌株对低浓度营养物的潜在偏好,本研究梯度稀释常用的锰氧化菌培养基(PYG培养基),配置出5级营养物梯度浓度的培养基.相对于原培养基,从较低浓度的4级培养基中多分离出6个菌属的锰氧化菌株,提高了锰氧化菌株的分离效率.分离出的Pseudoxanthomonas(假黄色单胞菌属)菌属的锰氧化菌株(Pseudoxanthomonas mexicana S5-3_5X),属中文文献首次报道.研究发现该菌株能在环境常见条件(pH 6.0~7.8、低营养物浓度(如稀释5~625倍PYG培养基)、50μmol·L^(-1)~1.6 mmol·L^(-1)的MnⅡ浓度)生长并产生锰氧化活性;可以产生胞外超氧化物和锰氧化蛋白等锰氧化活性物质;基因组具有编码锰氧化模式菌株Pseudomonas putida GB-1的3个Mn~Ⅱ氧化蛋白的同源基因,并且具有降解一些有机污染物的代谢通路.因此,该菌株具有较好的工程应用潜力.Mn-oxidizing microorganisms catalyze the formation of Mn oxides from Mn,which can enhance the degradation of trace organic pollutants in water treatment systems(such as manganese sand filters and wetlands)and the anaerobic oxidation of methane from sediment,thus being widely studied. The isolation of Mn-oxidizing bacteria with different ecological niches from the environment is an important basis for the bioaugmentation of the Mnoxidization process in the environment. According to the potential preference of Mn-oxidizing strains for low concentration of nutrients,a common Mn-oxidizing bacteria medium was series diluted to prepare five culture media with lower concentrations of nutrients. Compared with the original medium,Mn-oxidizing strains of additional 6 genera were isolated from the four diluted culture media,improving the isolation efficiency of Mn-oxidizing strains. An newly isolated Pseudoxanthomonas Mn-oxidizing strain(Pseudoxanthomonas mexicana S5-3_5X)was reported for the first time. The strain could grow under mild environmental conditions(pH 6.0~7.8;low nutrient concentration(e.g.,PYG culture media diluted 5 to 625times);Mnconcentrations was in the range of 50 μmol·L^(-1)to 1.6 mmol·L^(-1)). The strain produced Mn-oxidizing activity by producing both extracellular superoxide radical and Mn-oxidizing protein. Its genome encoded three Mn-oxidizing protein homologs of a Mn-oxidizing type stain Pseudomonas putida GB-1 and has metabolic pathways for degrading organic pollutants. Therefore,the strain has particular engineering application potential.

关 键 词：锰氧化细菌 培养组学 假黄色单胞菌 超氧自由基 

分 类 号：X172[环境科学与工程—环境科学] X703