16S rDNA克隆文库解析AO-MBR系统中细菌种群多样性

采用分子生物学手段16S rDNA克隆文库方法对缺氧/好氧膜生物反应器(AO-MBR)的好氧池与缺氧池中细菌进行了多样性研究.实验结果表明,好氧池污泥样品的克隆文库包括9个类群,其中变形菌(Proteobacteria)和拟杆菌(Bacteroidetes)在文库中所占比例最大,分别为37.04％和14.81％;其次是酸杆菌(Acidobacteria)、未培养菌(uncultured bacterium)、绿菌(Chlorobi)和未培养的绿弯菌(uncultured Chloroflexi bacterium)、浮霉状菌(Planctomycetes),分别为11.11％、11.11％、7.41％、7.41％和5.56％;硝化螺旋菌(Nitrospirae)和裸藻门(Euglenozoa)所占比例相对较小,均为1.85％.缺氧池样品克隆文库包括10个类群,其中变形菌(Proteobacteria)、拟杆菌(Bacteroidetes)和未培养菌(uncultured bacterium)在文库中所占比例最大,分别为27.91％、13.95％和12.79％;其次是浮霉状菌(Planctomycetes)、酸杆菌(Acidobacteria)和绿弯菌(Chloroflexi),在文库中所占比例分别为9.3％、9.3％和9.3％;硝化螺旋菌(Nitrospirae)、裸藻门(Euglenozoa)、芽单胞菌(Gemmatimonadetes)和放线菌(Actinobacteria)所占比例相对较少,分别为6.98％、8.14％、1.16％和1.16％.两池细菌的主要类群相似,但菌属及比例有所差异,变形菌是系统中的主要脱氮菌属.     

潮土细菌及真菌群落对化肥减量配施有机肥和秸秆的响应

为了研究化肥减量配施有机肥和秸秆对华北麦玉轮作田潮土细菌和真菌群落的影响,在天津市宁河区试验基地开展田间定位施肥试验,采用Illumina高通量测序技术比较了5种施肥模式（单施化肥处理,F;化肥减施处理,FR;化肥减量与秸秆配施处理,FRS;化肥减量与有机肥配施处理,FRO;化肥减量与有机肥和秸秆配施处理,FROS）下土壤细菌及真菌群落的组成、多样性和结构差异,并结合土壤理化性质分析,探究不同施肥处理下驱动细菌和真菌群落变化的关键土壤环境因子.结果表明,FRO处理显著提高了土壤SOM含量.FROS处理的TP含量显著高于FRS处理,增加了13.33%.FRO和FROS处理AP含量较其它处理显著增加,NH₄⁺-N含量显著高于化肥处理（F和FR）.各施肥处理土壤中优势细菌门类均为变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、绿弯菌门（Chloroflexi）和酸杆菌门（Acidobacteria）,优势真菌门类均为子囊菌门（Ascomycota）.在化肥减量配施有机肥（FRO）的基础上添加秸秆（FROS）显著降低了放线菌门（Actinobacteria）的相对丰度.FRS和FROS处理均显著降低了芽单胞菌门（Gemmatimonadetes）的相对丰度.FROS处理显著提高了浮霉菌门（Planctomycetes）和疣微菌门（Verrucomicrobia）的相对丰度.对于真菌群落而言,有机肥（FRO和FROS）的施入显著提高了子囊菌门（Ascomycota）的相对丰度.与FR处理相比,FROS处理显著降低了被孢菌门（Mortierellomycota）和油壶菌门（Olpidiomycota）的相对丰度,且FRS处理同样显著降低了油壶菌门（Olpidiomycota）的相对丰度.FROS处理的细菌群落Shannon多样性指数显著高于F和FR处理,分别增加了1.26%和1.25%,Chao1指数较F处理显著增加了4.51%,细菌Shannon多样性指数与AP和NH₄⁺-N含量显著正相关（P<0.05）.与FR处理相比,FRS、FRO和FROS处理显著降低了真菌群落Shannon多样性指数,分别达到29.85%、24.94%和25.73%,真菌Shannon多样性指数与AP含量显著负相关（P<0.05）.细菌群落结构在FROS处理下显著区别于F、FR和FRO处理,土壤SM、TP、pH和AP是导致细菌群落结构变化的主要驱动因子;真菌群落结构在FRO和FROS处理下显著区别于F和FR处理,真菌群落结构变化主要受土壤TN、AP和TP的驱动.综上所述,添加有机肥和秸秆改变了土壤理化性质,进而改变了土壤细菌和真菌群落组成,土壤真菌对有机物料的敏感程度高于细菌,细菌和真菌群落结构均受到土壤P的调控,在潮土农业耕作中应引起充分重视.     

O3-BAC深度处理工艺中细菌群落时空分布及动态变化规律

为弄清饮用水O₃-BAC深度处理工艺过程中细菌群落的时空分布和动态变化规律,本研究以我国南方某O₃-BAC深度处理工艺水厂为研究对象,采用NovaSeq6000高通量测序技术对夏季和冬季各工艺单元出水及滤砂和活性炭生物膜等细菌群落进行解析.结果表明,出厂水pH、浊度、COD_Mn、菌落总数等指标均满足《生活饮用水卫生标准》（GB5749-2006）的要求.夏季细菌群落多样性明显高于冬季,活性炭生物膜的细菌群落多样性高于滤砂生物膜;混凝沉淀、臭氧化和消毒是影响细菌群落多样性的主要工艺单元.水样和生物膜样品绝对优势菌门均为变形菌门（Proteobacteria）,且主要菌门组成大体相同,但细菌群落门水平相对丰度存在一定的时空差异,属水平上差异则更为明显.此外,检测到的条件致病菌属主要包括芽孢杆菌属（Bacillus）、不动杆菌属（Acinetobacter）、假单胞菌属（Pseudomonas）和分支杆菌属（Mycobacterium）,且其所占核心微生物OTUs数目不受季节性影响.水温和生物可降解溶解性有机碳（BDOC）是显著影响细菌群落分布的主要水质参数.以上研究结果表明,O₃-BAC深度处理工艺过程中细菌群落具有时空变化特性,并可为饮用水微生物安全保障提供支撑.     

地下水波动带中细菌群落结构与水质响应关系

为揭示地下水波动带中细菌群落结构特征及其与地下水环境相互作用关系,选取哈尔滨市第一水源地作为研究区,采集地下水样品以及波动带不同深度（0~5m非饱和带和6~50m饱和带）含水介质样品,分别用于水化学分析和16S rRNA细菌高通量测序,依托冗余分析定量表述地下水质参数与细菌群落相关性.水化学分析结果显示,研究区地下水主要污染物为Fe、Mn、NH₄⁺和有机质,Fe、Mn超标与研究区特定地质背景有关,NH₄⁺和有机质主要来源于人类活动.微生物分析结果显示,非饱和带和饱和带的细菌群落结构差异性显著,非饱和带细菌群落丰度和多样性显著高于饱和带,Proteobacteria、Bacteroidetes、Actinobacteria、Firmicutes和Acidobacteria为研究区优势门,在非饱和带和饱和带的累积相对丰度分别为82.89%和98.64%.冗余分析（RDA）结果显示,门水平上非饱和带中与水质演化强相关的细菌类群是Bacteroidetes、Proteobacteria、Actinobacteria、Verrucomicrobia,贡献率分别为15%、14.8%、8.9%和5.2%;饱和带中对地下水质演化起主要作用的类群为Bacteroidetes、Acidobacteria、Actinobacteria和Firmicutes,贡献率分别为38.4%、19.0%、10.8%和9.1%.属水平上非饱和带中的Pseudomonas和饱和带中的Flavobacterium对Fe、Mn、NH₄⁺生物转化起主导作用.本研究为揭示地下水波动带中生物地球化学作用对地下水环境的影响提供了科学依据,对地下水污染修复具有重要的意义.     

Bi-national assessment of the Great Lakes: SOLEC partnerships

Many administrative jurisdictions have authority over parts of the Great Lakes, sometimes with competing purposes as well as governance at differing scales of time and space. As demand increases for high quality information that is relevant to environmental managers, environmental and natural resource agencies with limited budgets must look to interdisciplinary, collaborative approaches for the collection, analysis and reporting of data. The State of the Lakes Ecosystem Conferences (SOLEC) were begun in 1994 in response to reporting requirements of the Great Lakes Water Quality Agreement between Canada and the U.S. The biennial conferences provide independent, science-based reporting on the state of health of the Great Lakes ecosystem components. A suite of indicators necessary and sufficient to assess Great Lakes ecosystem status was introduced in 1998, and assessments based on a subset of the indicators were presented in 2000. Because SOLEC is a multi-agency, multi-jurisdictional reporting venue, the SOLEC indicators require acceptance by a broad spectrum of stakeholders in the Great Lakes basin. The SOLEC indicators list is expected to provide the basis for government agencies and other organizations to collaborate more effectively and to allocate resources to data collection, evaluation and reporting on the state of the Great Lakes basin ecosystem.     

Land Degradation Monitoring in Namibia: A First Approximation

This paper presents development of a first approximation of a Namibian, national level, land degradation monitoring system. The process involved a large number of stakeholders and led to the definition of four primary indicators that were regarded as related to land degradation in Namibia: population pressure, livestock pressure, seasonal rainfall and erosion hazards. These indicators were calculated annually for the period 1971–1997. Annual land degradation risk maps were produced for the same period by combining the indicators. A time series analysis of results generated by indicators was undertaken at two sites. The analysis revealed a general trend towards an increased land degradation risk over the period 1971–1997. A decrease in annual rainfall and an increase in livestock numbers caused this negative trend at one site, while decreased annual rainfall and increased human population were the causes at a second site. Evaluation of resulting maps through direct field observations and long-term monitoring at selected study sites with different conditions relevant for the indicators defined, is an essential next step.     

Application of the benthic index of biotic integrity to environmental monitoring in Chesapeake Bay

The Chesapeake Bay benthic index of biotic integrity (B-IBI) was developed to assess benthic community health and environmental quality in Chesapeake Bay. The B-IBI provides Chesapeake Bay monitoring programs with a uniform tool with which to characterize bay-wide benthic community condition and assess the health of the Bay. A probability-based design permits unbiased annual estimates of areal degradation within the Chesapeake Bay and its tributaries with quantifiable precision. However, of greatest interest to managers is the identification of problem areas most in need of restoration. Here we apply the B-IBI to benthic data collected in the Bay since 1994 to assess benthic community degradation by Chesapeake Bay Program segment and water depth. We used a new B-IBI classification system that improves the reliability of the estimates of degradation. Estimates were produced for 67 Chesapeake Bay Program segments. Greatest degradation was found in areas that are known to experience hypoxia or show toxic contamination, such as the mesohaline portion of the Potomac River, the Patapsco River, and the Maryland mainstem. Logistic regression models revealed increased probability of degraded benthos with depth for the lower Potomac River, Patapsco River, Nanticoke River, lower York River, and the Maryland mainstem. Our assessment of degradation by segment and water depth provided greater resolution of relative condition than previously available, and helped define the extent of degradation in Chesapeake Bay.     

Forest Health Assessment and Monitoring – Issues for Consideration

Part of this paper has been prepared for the lecture Forest Health Assessment-Criteria,Methods and Problems given by the author at the UIMPuniversity course Sanidad Forestal en el Bosques Mediterraneos yTemplados. Implicacion de la Contaminacion Atmosferica y del Cambio Global, held in Valencia, Spain, October, 1995. Assessment and monitoring of forest health representsa key point for environmental policy and for the management ofenvironmental resources. With the renewed interest in assessment andmonitoring of forest health generated by the suspected occurrence ofa widespread forest decline in Europe and North America, manyactivities have been undertaken: however, some questions should beconsidered and clarified when attempting to estimate forest health.Particularly, the objective(s) of the assessment and monitoringprogram should be carefully identified. Identification of a program‘stask has a number of implications and consequences: it implies adefinition of what concept of forest health (forest ecosystem health,forest health or forest trees health?) is assumed, what will be thetarget entity to be monitored, and therefore the identification of therelevant assessment questions and assessment endpoints.Consequences concern the definition of the spatial scale (frominternational to landscape and plot scale monitoring) and ecologicalcoverage (from single species population to population ofecosystems) of the program, which can have a considerable influenceon the choice of the proper sampling strategy and tactic, as well ason the most suitable methods, indicators and indices to be used.Although much of the work in the field of forest health and airpollution has concentrated on surveys on crown transparency anddiscoloration, there is an entire range of methods, indicators andindices developed to assess the health status of forests. The decisionas to which ones should be used will depend on the aim of theprogram and on economic and practical considerations. A furtherconsideration concerns the time span of the program, but anydecision in this field is subject to many limitations due to difficultiesin predicting future monitoring needs. All these points should becarefully considered and implemented according to a rigorousQuality Assurance procedure since any decision will influence futurework for many years.     

Indicators of sustainable production: framework and methodology

This paper presents a new tool for promoting business sustainability — indicators of sustainable production. It first introduces the concept of sustainable production as defined by the Lowell Center for Sustainable Production, University of Massachusetts Lowell. Indicators of sustainable production are discussed next, including their dimensions and desirable qualities. Based on the Lowell Center Indicator Framework, the authors suggest a new methodology of core and supplemental indicators for raising companies' awareness and measuring their progress toward sustainable production systems. Twenty-two core indicators are proposed and a detailed guidance for their application is included. An eight-step model provides a context for indicator implementation. The paper concludes with a summary of the strengths and weaknesses of the methodology as well as recommendations for testing the indicators.