北京市夏季空气微生物群落结构和生态分布

着重研究北京市夏季空气微生物的群落结构和生态分布特征。结果表明 :北京市夏季空气中革兰氏阳性菌明显多于革兰氏阴性菌 ,约占 70 %～ 85 % ,其中阳性球菌占总数的占 35 %～ 4 5 %。 3个功能区 (文教区、交通干线和公园绿地 )共发现 30属空气细菌 ,其中革兰氏阳性菌 2 0属 ,革兰氏阴性菌 10属。优势细菌属为微球菌属 (Micrococcus)、芽孢杆菌属 (Bacillus)、葡萄球菌属 (Staphylococcus)和假单胞菌属 (Pseudomonas)。 3个功能区共出现 10属空气真菌 ,优势菌属枝孢属 (Cladosporium)、链格孢属 (Alternaria)、无孢菌 (nonsporing)、青霉属 (Penicillium)和曲霉属 (Aspergillus) ,其中枝孢属是绝对优势菌属 ,占总数的4 8.2 %。空气细菌浓度交通干线和文教区明显高于公园绿地 ,而空气真菌浓度公园绿地和文教区明显高于交通干线。空气细菌浓度一日中 13:0 0时较低 ,0 9:0 0时和 17:0 0较高     

合肥城区空气真菌浓度的时空分布特征

研究空气真菌群落结构和分布特征可为制定空气真菌污染防治对策和环境治理提供科学依据。我们于2005年7月至2006年6月,采用仪器采样法分别在居住区、交通干线、中心商业区、公园绿地4个功能区对合肥城区空气中的真菌进行了监测。结果表明,合肥城区空气已受到不同程度的真菌污染。城区空气中共分离得到真菌35个属,优势属为曲霉属（Aspergillus）、青霉属（Penicillium）、毛霉属（Mucor）、根霉属（Rhizopus）、木霉属（Trichoderma）。空气真菌平均浓度为2,744CFU/m3,真菌浓度在居住区、中心商业区、公园绿地3个功能区由早、中、晚逐渐升高;在交通干线中午较高、早晚较低。空气真菌浓度的季节变化在居住区和交通干线不明显,而在中心商业区和公园绿地表现为春秋季较高,夏冬季较低。空气真菌浓度的全年变化在居住区和交通干线不明显,而在中心商业区的4月与10月、公园绿地的4月与9月,空气真菌浓度显著高于全年其他月份。空气真菌浓度分布的时空特征不仅与环境因素、大气污染等因素有关,还受到人类活动和植被等因素的影响。     

北京城市空气细菌群落结构与动态变化特征

在北京市选择3个典型的功能区,通过定点系统取样,运用BIOLOG鉴定技术,着重研究了北京城市空气细菌的群落结构与动态变化特征。结果表明:北京市空气中革兰氏阳性菌明显多于革兰氏阴性菌,约占80%~85%,其中阳性球菌占总数的50%~55%。不同功能区共发现47属空气细菌,其中革兰氏阳性菌31属,革兰氏阴性菌16属。优势菌属依次为微球菌属(Micrococcus)、葡萄球菌属(Staphylococcus)、芽孢杆菌属(Bacillus)、棒杆菌属(Corynebacterium)和假单胞菌属(Pseudomonas),它们总和约占50%。在优势菌属中,微球菌属约占总数的20%~30%,是北京市空气中比例最大的菌属,假单胞菌属约占2.5%~5.0%。文教区和交通干线细菌浓度明显高于公园绿地(P<0.01);并且文教区和交通干线空气细菌浓度四季变化特征显著,夏季和秋季较高,春季和冬季较低,公园绿地空气细菌浓度四季没有显著差异;3个功能区13:00时的细菌浓度明显低于9:00时和17:00。     

城市生态系统空气微生物群落研究进展

空气微生物是城市生态系统重要的生物组成部分 ,空气中广泛分布的细菌、真菌孢子、放线菌和病毒等生物粒子不仅具有极其重要的生态功能 ,还与城市空气污染 ,城市环境质量和人体健康密切相关。从生态系统角度出发 ,着重论述了城市微生物气溶胶的粒谱范围、空气微生物的主要类型、空气微生物浓度的时空变化和空气微生物群落结构的影响因素。综述结果表明 :城市微生物气溶胶的粒谱范围为 0 .0 0 2～ 30 μm;在调查的城市中 ,空气细菌有 2 1属 ,其中优势菌属为芽孢杆菌属 (Bacillus)、葡萄球菌属 (Staphylococcus)、微球菌属 (Micrococcus)和微杆菌属 (Microbacterium ) ,真菌有 2 1属 ,其中优势菌属为交链孢属(Alternaria)、青霉属 (Penicillium)、曲霉属 (Aspergillus)和木霉属 (Trichoderma) ,放线菌共有 7属 ;一年中冬季空气微生物浓度最低 ,一天中空气微生物浓度在 8:0 0～ 10 :0 0出现高峰 ,2 :0 0～ 4 :0 0或者 12 :0 0～ 14 :0 0出现低峰 ,交通干线和商业区空气微生物的浓度较高 ,公园绿地较低 ,并且随着高度的增加空气微生物浓度随之减少 ;污染因子 SO2 、NO2 、NO和环境因素风速风向、温度、相对湿度、光照、雨、雪等影响空气微生物的数量和浓度。在经济发达 ,人口流动较多的城市如北京、上海、广     

北京城区道路沉积物污染特性

为了解城市道路沉积物污染物的浓度水平及可能造成的生态环境危害,在北京城区的生活区、文教区、交通干线和公园绿地这四种功能区的道路沉积物进行了取样监测,并分析了道路沉积物中总氮(TN)、总磷(TP)、重金属铜(Cu)、铬(Cr)、铅(Pb)、锌(Zn)和有机质(TOC)的污染特性.研究结果表明,各类功能区道路沉积物中TN、TP和TOC的含量较高.交通干线、文教区、生活区和公园绿地道路沉积物TN均值分别为0.1009、0.1440、0.1071、0.0974mg/kg,文教区道路沉积物的TN显著高于其他类型道路沉积物;TP均值分别为0.0695、0.0729、0.0665、0.0608mg/kg,以文教区最高,但未达显著水平.交通干线和文教区道路沉积物TOC浓度显著高于生活区和公园绿地,交通干线、文教区和生活区道路沉积物重金属的含量高于公园绿地.主要原因可能是人类活动和车辆交通量的影响.四类功能区氮主要以可溶态赋存,磷主要以颗粒态赋存在沉积物中,并且交通干线道路沉积物中溶解态磷比例最低.溶解态的重金属占总量的比例均较低,只有溶解态Cu达到5％以上,表明重金属主要赋存在颗粒态存在的沉积物中.道路沉积物或者外界带入的固体物质是地表径流污染物的重要来源,研究结果为城市地表污染控制提供重要参考.     

黄山风景区夏季空气微生物分布特征初步研究

用自然沉降法测定了黄山风景区夏季旅游旺季14个景点的空气微生物浓度,并研究其种属构成和分布特征.结果表明:黄山风景区夏季空气细菌平均值为0.41×104 CFU/m3,真菌平均值为0.34×104 CFU/m3,总菌平均值为0.75×104CFU/m3,真菌占总茵的百分比为45.9%,黄山风景区空气已受到不同程度的微生物污染;对不同采样点的空气细菌和真菌进行了初步鉴定,空气细茵共有6属,其中优势细菌属为芽孢杆菌属(Bacillus)、葡萄球茵属(Staphylococcus)、微球菌属(Micrococcus)和假单胞菌属(Pseudomonas),分别占总细菌的37.7%、17.2%、10.1%、9.8%;真菌除无孢茵群外共有5属,其中优势菌属为芽枝霉属(Cladosporium)、无孢菌群(Mycelia sterilia)、青霉属(Penicillium)和交链孢霉属(Alternaria),分别占总真菌的40.4%、35.0%、5.6%、4.3%;空气微生物浓度的分布具有时空特征,这不仅与黄山风景区特有的地形地貌以及气候特征有关,还受到游客活动、动植物等因素的影响.     

华西雨屏区不同恢复阶段湿性常绿阔叶林的土壤微生物多样性

采用时空互代的方法,探讨了崇州市鞍子河自然保护区和邛崃市天台山的常绿阔叶林自然恢复过程中土壤微生物数量、组成、区系和多样性变化,结果表明：（1）不同恢复时期土壤微生物数量存在显著性差异,在植被恢复5～40a期间,土壤细菌和放线菌的数量呈增加趋势,以恢复到40a植被土壤微生物总数、细菌和放线菌的数量较高,分别为1．06×10^6CFUg^-1干土、9．81×10^5CFUg^-1干土和6．8×10^4CFUg^-1干土;真菌以100a次生林较高,为9．01×10^4CFUg^-1干土;植被恢复中细菌占土壤微生物总数的79．06％～93．78％;真菌和放线菌数量分别占4．61％～11．24％和0．52％～15．38％;（2）不同恢复阶段土壤细菌和真菌数量大体上以夏季高,春、秋季较低;放线菌数量为春、秋季较夏季高;（3）植被恢复过程中,土壤微生物群落区系和优势种群组成不同,经鉴定有细菌10个属、真菌7个属、放线菌9个属,细菌以无色细菌属（Achromobater）、棒状杆菌属（Corynebacterium）、短杆菌属（Brevibacterium）和芽孢杆菌属（Bacillus）出现的几率较高;真菌主要是半知菌类和接合菌类,以木霉属（Trichoderma）、腐霉属（Pythium）、青霉属（Penicillium）和犁头霉属（Absidia）分布较为普遍;放线菌9个类群中8个属于链霉菌属（Streptomyces）,仅有1个类群属于小单孢菌属（Micromonospora）,以白孢类群（Albosporus）、金色类群（Aureus）和灰红紫类群（Griseorubroviolaceus）出现几率为较高;（4）细菌属的Shannon—Wiener指数、Simpson指数以恢复初期、30a生次生林和较原始植被为较高。在植被恢复5～50a期间,真菌和放线菌属的多样性呈波动性增加趋势,到50a达到最高;50a以后,呈下降趋势,表明植被恢复的30～50a土壤环境更适合真菌和放线菌的生长。     

毛乌素沙地南缘沙丘生物结皮中微生物分布特征

为探明半干旱沙区生物结皮中微生物分布特征,对毛乌素沙地南缘沙丘生物结皮中微生物数量进行了测定。结果表明:微生物总数从丘顶到丘间地呈递增趋势,除丘顶与迎风坡、迎风坡与背风坡结皮层微生物总数差异不显著外,其他各地貌部位结皮层微生物数量之间差异显著。同一地貌部位结皮层、0～5和5～10cm土层微生物垂直分布有变化,其变化规律为:除迎风坡放线菌数量呈先增加后递减、迎风坡微生物总数、细菌、真菌和丘顶真菌数量随剖面的加深呈递减外,其他各地貌部位微生物数量均呈先降低,后增加的趋势。微生物类群的组成表现为细菌最多,放线菌次之,真菌最少。在丘间地细菌所占微生物总数的比例与丘顶相比有所增加,而放线菌和真菌的比例有所减少。结皮下0～5和5～10cm土层微生物分布与土壤含水量的变化同步,说明土壤水分可能是影响微生物垂直分布的重要因子。     

不同种植年限菜田土壤微生物区系的研究

采用稀释平板涂抹法对山东聊城周边地区不同种植年限的菜田土壤微生物数量、组成与养分状况及其相互关系进行了研究。结果表明：①该地区土壤微生物以细菌占绝对优势,其次为放线菌;②随着种菜年限的增加,土壤细菌和微生物总数表现出“低高低”的变化趋势,而真菌和放线菌则随种菜年限的增加而增加;③菜田土壤各类微生物主要集中在0～20cm的土层中,随着土层加深,其数量迅速减少;④菜田土壤放线菌组成复杂,共分离到了6个属的放线菌,但仍以链霉菌为主,其次为小单胞菌属和马杜拉放线菌属。链霉菌可分为9个类群,白孢类群占优势。种植1—2a的菜田土壤放线菌组成复杂,而链霉茼组成较简单;⑤蔬菜种类不同时,土壤微生物亦不同;⑥土壤养分含量与真菌和放线菌呈负相关,与细菌和微生物总数呈正相关。     

塔克拉玛干沙漠腹地人工植被下土壤微生物的初步研究

在极端干旱的塔克拉玛干沙漠腹地利用矿化度为4～5 g/L的地下咸水灌溉,在风沙土上建立了人工绿地。对流沙和人工绿地中微生物三大类群（细菌、真菌和放线菌）进行了数量测定,结果显示：流沙上微生物数量很少,人工绿地的微生物数量显著增加;种植时间相同而植被类型不同的样地中的微生物数量有差异;微生物的组成中,细菌占绝大多数,达微生物总数的90%以上,其次是放线菌,真菌数量最少;表层微生物数量明显高于下层。人工绿地微生物数量的变化,说明风沙土已逐步向具有一定肥力水平的土壤方向演变。     

Seasonal variability in bacterial and fungal diversity and community composition of the near-surface atmosphere in coastal megacity

Bacteria and fungi are ubiquitous in the near-surface atmosphere where they may impact on the surrounding environment and human health, especially in coastal megacities. However, the diversity, composition, and seasonal variations of these airborne microbes remain limited. This study investigated the airborne microbes of the near-surface atmosphere in coastal megacity Qingdao over one year. It was found that the sample in summer displayed the highest bacterial and fungal diversity, while sample in winter exhibited the lowest bacterial and fungal diversity. Proteobacteria was the dominating bacteria, and Dothideomycetes was the most dominating fungi in the near-surface atmosphere, which took up 53–76 and 49–78% relative abundance, respectively. However, the bacterial diversity and community composition had significant seasonal variations. These data suggest that a complex set of environmental factors, including landscaping ratio, solar radiation temperature, and marine microorganisms, can affect the composition of airborne microbes in the near-surface atmosphere in coastal megacity. The analysis of the pathogenic microorganisms or opportunistic pathogenic microorganisms existed in the near-surface atmosphere revealed that the relative abundance of pathogenic microorganisms in autumn was the highest. The main pathogenic microorganisms or opportunistic pathogenic microorganisms were Acinetobacter baumannii (accounting for up to 9.93% relative abundance), Staphylococcus epidermidis (accounting for up to 11.26% relative abundance), Mycobacterium smegmatis (accounting for up to 3.68% relative abundance), Xanthomonas oryzae pv. oryzae (accounting for up to 5.36% relative abundance), which may be related to certain human or plant diseases in specific environments or at certain seasons. Therefore, the investigation of airborne microbial communities of near-surface atmosphere in coastal megacities is very important to both the understanding of airborne microbes and public health.     

青岛市不同功能区冬季空气微生物群落代谢与多样性特征

选取青岛市5个功能区(市区街道、海滨区域、饮用水源地、垃圾填埋场和人工湿地污水处理系统),采用SAS ISO100空气浮游菌采样器于2013年冬季采集空气微生物样品,应用BIOLOG方法分析空气微生物群落代谢功能多样性,阐明群落代谢与环境相关性。结果表明,不同功能区空气微生物群落碳源代谢强度存在差异,代谢稳定时,海滨区域和饮用水源地样品平均光密度值(AWCD)分别为0.302、0.210,而人工湿地、市区街道及垃圾填埋场分别为0.063、0.025和0.034,海滨区域和饮用水源地空气微生物群落碳源代谢强度明显高于其他功能区。不同功能区空气微生物群落Shannon指数和Simpson指数接近,但海滨区域和饮用水源地Mc Intosh指数明显高于其他功能区。海滨区域和饮用水源地空气微生物群落碳源代谢类型丰富,代谢水平高,人工湿地、市区街道和垃圾填埋场碳源代谢类型单一,代谢水平低。5个功能区空气微生物群落碳源代谢差异呈现区域性,分异代谢差异的主要是羧酸类碳源。风速、温度、湿度等非生物因素对空气微生物群落碳源代谢具有不同程度影响,且不同功能区主导非生物因素存在差异。BIOLOG方法可以提供大量多维数据,能够分析样品间微生物群落碳源代谢差异,客观、全面表征空气微生物群落碳源代谢多样性特征,是研究空气微生物群落功能多样性较理想的方法之一。     

Size distribution of viable, cultivable, airborne microbes and their relationship to particulate matter concentrations and meteorological conditions in a Mediterranean site

The biological loading of viable, cultivable airborne microbes (heterotrophic bacteria, actinobacteria and fungi) in 6 size fractions as well as the three different fractions of respirable particulate matter (PM₁, PM_2.5 and PM₁₀) and their relationship to meteorological conditions were studied in the ambient air due to health-related interests. An Andersen six stage viable particle impactor and a MAS 100 sampler were used for microbial measurements. 82 measurements were performed at three different periods (41 days) at a suburban, residential site in the city of Chania (Crete, Greece) during the period from April 2008 to June 2009. The concentrations of the viable, cultivable airborne microbes (bioaerosols) as well as of the PM₁, PM_2.5 and PM₁₀ were highly variable during the whole measurement period. Among the airborne microbes, fungi presented the most abundant taxonomic group in the ambient air. A characteristic profile of the mean size distribution of biological loading in different PM fractions was obtained for every measured microbial taxonomic group. Although, the highest concentrations of the airborne fungi and actinobacteria were determined at aerodynamic diameters between 2.1 and 3.3 μm, a nearly equal distribution of the mean concentrations of the airborne heterotrophic bacteria was observed in the six different size fractions. However, two small maxima were observed at the airborne heterotrophic bacteria distribution, one at the fraction with aerodynamic diameters between 1.1 and 2.1 μm, and at other at the coarse fraction with aerodynamic diameter larger than 7 μm. A considerable part of the airborne microbes Cycloheximide per mL of growth medium of bacteriwere resistant to drugs. Between 10 and 40 % of the viable, cultivable airborne microbes were resistant to low concentrations of drugs (5–10 μg of Streptomycin or a or fungi, respectively). Furthermore, multiple linear regression of the data showed that the variation in fungi concentrations depends on the variation in PM₁₀ mass concentration, PM₁ number concentration, relative humidity and solar radiation. Likewise, the concentration of heterotrophic bacteria was found proportional to the values of relative humidity and fungal concentration, whereas was negatively correlated to the solar radiation.     

Short-Term Temporal Variability in Airborne Bacterial and Fungal Populations

Airborne microorganisms have been studied for centuries, but the majority of this research has relied on cultivation-dependent surveys that may not capture all of the microbial diversity in the atmosphere. As a result, our understanding of airborne microbial ecology is limited despite the relevance of airborne microbes to human health, various ecosystem functions, and environmental quality. Cultivation-independent surveys of small-subunit rRNA genes were conducted in order to identify the types of airborne bacteria and fungi found at a single site (Boulder, CO) and the temporal variability in the microbial assemblages over an 8-day period. We found that the air samples were dominated by ascomycete fungi of the Hypocreales order and a diverse array of bacteria, including members of the proteobacterial and Cytophaga-Flavobacterium-Bacteroides groups that are commonly found in comparable culture-independent surveys of airborne bacteria. Bacterium/fungus ratios varied by 2 orders of magnitude over the sampling period, and we observed large shifts in the phylogenetic diversity of bacteria present in the air samples collected on different dates, shifts that were not likely to be related to local meteorological conditions. We observed more phylogenetic similarity between bacteria collected from geographically distant sites than between bacteria collected from the same site on different days. These results suggest that outdoor air may harbor similar types of bacteria regardless of location and that the short-term temporal variability in airborne bacterial assemblages can be very large.     

Factors of influence on microbial pollution in the atmosphere over Beijing area

Summary The atmospheric microbial pollutants are potentially correlated to population density and activity as well as to human health. The higher the population density is, the heavier the air microbial pollution will become. Some meteorological factors exert great influence on air microbial pollution. Generally, wind, solar radiation and rainfalls purify air and, consequently cause a decrease in atmospheric microbial pollution. On the other hand, prevailing strong winds may favour this pollution, especially in dry conditions and in absence of vegetation. Obviously, relatively high temperatures associated with high RH enhance the growing of microbes. However, the higher the temperature is, the lower the viability of airborne microbes will be; nonetheless, with high RH a decrease in suspended particles may be recorded.     

Human occupancy as a source of indoor airborne bacteria

Exposure to specific airborne bacteria indoors is linked to infectious and noninfectious adverse health outcomes. However, the sources and origins of bacteria suspended in indoor air are not well understood. This study presents evidence for elevated concentrations of indoor airborne bacteria due to human occupancy, and investigates the sources of these bacteria. Samples were collected in a university classroom while occupied and when vacant. The total particle mass concentration, bacterial genome concentration, and bacterial phylogenetic populations were characterized in indoor, outdoor, and ventilation duct supply air, as well as in the dust of ventilation system filters and in floor dust. Occupancy increased the total aerosol mass and bacterial genome concentration in indoor air PM(10) and PM(2.5) size fractions, with an increase of nearly two orders of magnitude in airborne bacterial genome concentration in PM(10). On a per mass basis, floor dust was enriched in bacterial genomes compared to airborne particles. Quantitative comparisons between bacterial populations in indoor air and potential sources suggest that resuspended floor dust is an important contributor to bacterial aerosol populations during occupancy. Experiments that controlled for resuspension from the floor implies that direct human shedding may also significantly impact the concentration of indoor airborne particles. The high content of bacteria specific to the skin, nostrils, and hair of humans found in indoor air and in floor dust indicates that floors are an important reservoir of human-associated bacteria, and that the direct particle shedding of desquamated skin cells and their subsequent resuspension strongly influenced the airborne bacteria population structure in this human-occupied environment. Inhalation exposure to microbes shed by other current or previous human occupants may occur in communal indoor environments.     

Oral microbiomes: more and more importance in oral cavity and whole body

Microbes appear in every corner of human life, and microbes affect every aspect of human life. The human oral cavity contains a number of different habitats. Synergy and interaction of variable oral microorganisms help human body against invasion of undesirable stimulation outside. However, imbalance of microbial flora contributes to oral diseases and systemic diseases. Oral microbiomes play an important role in the human microbial community and human health. The use of recently developed molecular methods has greatly expanded our knowledge of the composition and function of the oral microbiome in health and disease. Studies in oral microbiomes and their interactions with microbiomes in variable body sites and variable health condition are critical in our cognition of our body and how to make effect on human health improvement.