Cd对欧美杂交杨生长紫色土和冲积土微生物多样性的影响

研究了现实环境中cd污染水平对长江流域典型土壤微生物多样性的影响,分析了现实Cd浓度胁迫对盆栽欧美杂交杨（Populus deltoides×Populus nigra）生长的紫色土和冲积土中可培养的微生物数量、生物量和细菌群落多样性的影响．结果表明,cd处理显著增加了栽植杨树的紫色土中可培养细菌和放线菌数量,降低了可...     

西安市不同天气下可培养微生物气溶胶浓度变化特征

为探明天气状况对可培养微生物气溶胶分布特性的影响,于2014年8月-2015年7月利用Anderson六级空气微生物采样器对西安市微生物气溶胶进行采样,通过培养法检测分析了可培养细菌和真菌气溶胶在1 a的月际与季节性浓度变化特征,重点研究了不同天气状况下气溶胶的浓度与粒径分布.结果表明:西安市可培养细菌和真菌气溶胶月均浓度均在10月最高,分别为（1 004.81±546.14）和（765.54±544.36）CFU/m3.可培养细菌和真菌气溶胶的季节平均浓度均在夏季最低,分别为（361.96±56.96）和（280.33±74.43）CFU/m3;不同天气条件下气溶胶的浓度变化为晴天 < 雨天 < 阴云天 < 霾天.可培养细菌气溶胶在晴天、阴云天、雨天和霾天粒径分布的峰值分别出现在3.3~4.7、4.7~7.0、3.3~4.7、3.3~4.7 μm区间上,表现为明显的单峰分布;而可培养真菌气溶胶的粒径分布在非霾天则无显著性差异（P>0.05）.不同天气状况下可呼吸微生物气溶胶均超过总微生物气溶胶的60%.各天气状况下可培养细菌气溶胶的几何中值直径大于真菌气溶胶.      

用Matlab/Simulink建立废水处理仿真模型

国际水质协会(IWA)和欧盟科学技术合作组织(COST)合作开发的活性污泥废水处理基准仿真模型BSM1(benchmark sim-ulation model NO.1),主要目的是为了建立一个活性污泥过程控制方案的开发平台。文章比较详细的介绍了如何用Matlab和Simulink建立BSM1,对于如何得到正确的开环仿真结果给出了详细的说明,并将两种建模方式在仿真结果、仿真速度、建模的难易程度等方面进行了比较。     

Effect of amendments on the leaching behavior of alkaline anions and metal ions in bauxite residue

A column leaching experiment was used to investigate the efficacy of amendments on their ability to remove alkaline anions and metal ions from bauxite residue leachates. Treatments included, simulated acid rain(AR), phosphogypsum + vermicompost(PVC), phosphogypsum +vermicompost + simulated acid rain(PVA), and biosolids + microorganisms(BSM) together with controls(CK). Results indicated that amendment could effectively reduce the leachate pH and EC values, neutralize OH~-, CO_3~(2-), HCO_3~-, and water soluble alkali, and suppress arsenic(As)content. Correlation analysis revealed significant linear correlations with pH and concentrations of OH~-, CO_3~(2-), HCO_3~-, water-soluble alkali, and metal ions. BSM treatment showed optimum results with neutralizing anions(OH~-, CO_3~(2-), and HCO_3~-), water soluble alkali, and removal of metal ions(Al, As, B, Mo, V, and Na), which was attributed to neutralization from the generation of small molecular organic acids and organic matter during microbial metabolism. BSM treatment reduced alkaline anions and metal ions based on neutralization reactions in bauxite residue leachate, which reduced the potential pollution effects from leachates on the soil surrounding bauxite residue disposal areas.     

管材对供水管网生物膜微生物种群多样性的影响

研究了3种管材(灰口铸铁管、镀锌管和不锈钢复合管)对管网生物膜微生物种群多样性的影响.采用R2A平板培养计数可培养细菌、荧光定量PCR计数细菌总数、流式细胞法确定活菌比例、扫描电镜观察生物膜形态,高通量测序研究管段生物膜微生物种群多样性.研究结果表明:灰口铸铁管可培养菌数和细菌总数都最高,其次是镀锌管,不锈钢复合管可培养菌数和细菌总数都最少,但活菌比例方面镀锌管活菌比例高于灰口铸铁管和不锈钢复合管.扫描电镜结果与可培养菌数及细菌总数结果一致,即灰口铸铁管细菌量最高,不同管材管壁生物膜细菌形态皆以球菌和杆菌为主,并无显著差异.微生物种群多样性结果显示:灰口铸铁管生物膜种群多样性最高,镀锌管生物膜种群多样性相对较为单一,不锈钢复合管生物膜种群多样性最低.饮用水管网生物膜种群以变形菌门为主,各管道变形菌门都高达90%以上,不同管材生物膜细菌群落组成有很大差异.本研究结果对今后饮用水供水管段材料的选取具有指导性意义.     

Adsorption characteristic of bensulfuron-methyl at variable added Pb2+ concentrations on paddy soils

The combined pollution of heavy metal Pb2+ and bensulfuron-methyl (BSM), originating from chemical herbicides, in agro- ecological environments has become commonplace in southern China. The adsorption of BSM on three paddy soils in the presence of Pb2+ was examined using high-performance liquid chromatograph (HPLC). Results indicated that adsorption of BSM could accurately be described by a Freundlich isotherm equation with correlation constant (R) > 0.98, irrespective of the presence of spiked Pb2+. Of the...     

Adsorption characteristic of bensulfuron-methyl at variable added Pb^2＋ concentrations on paddy soils

The combined pollution of heavy metal Pb²⁺ and bensulfuron-methyl (BSM), originating from chemical herbicides, in agroecological environments has become commonplace in southern China. The adsorption of BSM on three paddy soils in the presence of Pb²⁺ was examined using high-performance liquid chromatograph (HPLC). Results indicated that adsorption of BSM could accurately be described by a Freundlich isotherm equation with correlation constant (R) > 0.98, irrespective of the presence of spiked Pb²⁺. Of the various factors influencing BSM sorption, soil pH appeared to be the most influential. The constant K_f of Freundlich isotherm equation tended to increase with increasing Pb²⁺ concentration in soil which indicated that the spiked of Pb²⁺ in paddy soils would promote the sorption of BSM. ΔG^θ of BSM in three paddy soils was less than 40 kJ/mol in all treatments, indicating the adsorption of BSM is mainly physical in nature. The elution of soil dissolved organic matter (DOM) enhanced the adsorption of BSM in paddy soils. The mechanisms involved in the promotion effects of the spiked Pb²⁺ on BSM adsorption might be the modified surface characteristics of paddy soil solids due to the soil acidification and the increase of soil organic matter concentration because of DOM binding.     

Expression of sulfur uptake assimilation-related genes in response to cadmium, bensulfuron-methyl and their co-contamination in rice roots

The responses of sulfur （S） uptake assimilation-related genes＇ expression in roots of two rice cultivars to cadmium （Cd）, bensulfuron-methyl （BSM） and their co-contamination （Cd＋BSM） were investigated by gene-chip microarray analysis and quantitative real-time PCR （QRT-PCR） technology. Treatments of Cd and Cd＋BSM induced expression of sulfate transporter and permease genes, and promoted sulfate uptake in rice roots. Cd＋BSM could alleviate Cd toxicity to cv. Fengmeizhan seedlings, probably due to Cd＋BSM promoting greater S absorption by seedlings. Cd and Cd＋BSM induced expression of sulfate assimilation-related genes, and thus activated the sulfur assimilation pathway. Cd and Cd＋BSM induced expression of phytochelatin synthase and metallothionein genes, and induced expression of glutathione S-transferases （GSTs）, glutathione synthase （GS） and S- containing antioxidation enzyme genes, which detoxified Cd2＋. It is suggested that （to cope with the toxicity of Cd, BSM and their co-contamination） the S uptake and assimilation pathway was activated in rice roots by increased expression of related genes, thus enhancing the supply of organic S for synthesis of Cd or BSM resistance-related substances.     

Monitoring impact of mefenacet treatment on soil microbial communities by PCR-DGGE fingerprinting and conventional testing procedures

The effect of acetanilide herbicide mefenacet on soil microbial communities was studied using paddy soil samples with different short-term treatments. The culturable bacteria （plate counts）, dehydrogenase activity and changes in community structure （denaturing gradient gel electrophoresis （DGGE） analysis） were used for biological community assessments. Mefenacet was a significant stimulus to cultural aerobic bacteria and dehydrogenase activity while Sphingobacterium multivorum Y1, a bacterium efficiently degrading the mefenacet, only induced the increasing colony-forming unit （CFU） of bacteria but little effect on dehydrogenase activity during the whole experiment. The degree of similarity between the 16S rDNA profiles of the communities was quantified by numerically analyzing the DGGE band patterns. Similarity dendrograms showed that the microbial community structures of the mefenacet-treated and non-treated soils were not significantly different. But supplement of S. multivorum Y1 could increase the diversity of the microbial community in the mefenacet-polluted paddy soil. This work is a new attempt to apply the S. multivorum Y1 for remediation of the mefenacet-polluted environments.     

镉和乙草胺、苄嘧磺隆对水稻吸收能力的影响

为探讨镉和两种常用除草剂的复合污染对水稻吸收必需矿质元素影响,采用水培法研究了镉(Cd)、乙草胺(AC)和苄嘧磺隆(BSM)在单一及复合污染条件下处理水稻幼苗72h及解除污染并恢复培养96小时后,水稻基本营养元素含量的变化,并对水稻幼苗根系损伤情况也进行了研究。研究发现:Cd和AC、BSM单一和复合处理降低了水稻根系Mn、Cu、Zn的含量。AC单独处理增加了水稻根系Fe的含量,Cd与AC、BSM联合作用时则降低了水稻根系Fe的含量。AC单一及Cd与AC和BSM的复合作用能增加水稻地上部分Fe的含量,最高可达对照的4.5倍。Cd降低了水稻幼苗对Mg的吸收,而AC和BSM却能促进对Mg的吸收。水稻幼苗经96h的恢复培养后,其根和地上部分叶营养元素含量也发生了一些重要的变化,水稻幼苗地上和地下部分Cd的含量发生了显著性下降。Cd和乙草胺、苄嘧磺隆在单独和联合作用下根系和叶片相对电导率、MDA含量都较对照有所升高,而根系活力下降。     

添加猪粪对不同施肥历史土壤细菌群落的影响

为探讨粪肥携带的微生物对土壤微生物的影响，以长期施用粪肥和化肥的土壤为研究对象，耦合传统微生物学培养方法和现代分子微生物学方法，分析了猪粪和灭菌猪粪对2种土壤的细菌数量、群落结构和热代谢活性的影响.结果表明，以9.0t/hm²的用量施入时，猪粪和灭菌猪粪对两种土壤中的可培养细菌数量以及细菌16S-rRNA拷贝数均无明显影响；土壤中的土著微生物对猪粪携带的外源细菌在土壤中定殖具有明显的抑制作用，将2种土壤灭菌后添加猪粪，可培养细菌平均数量较未灭菌土壤分别增加45.96和96.21倍.粪肥输入的化学物质未导致土壤细菌群落结构和相对丰度发生明显变化；而粪肥输入的外源细菌Marinilabiaceae、Porphyromonadaceae、Bacteroidale和Pseudomonadaceae则可以在长期施用化肥的土壤中定殖并对相应的细菌丰度造成影响，但是在长期施用粪肥的土壤中，这些细菌在最开始就被抑制.添加粪肥提高了长期施用化肥土壤的微生物热代谢活性，但对长期施用粪肥的土壤无明显影响.长期施用化肥的土壤受粪源细菌的影响较大，而长期施用粪肥的土壤对粪肥的敏感度降低，对粪肥携带的外源细菌的抑制作用增强.     

Organic carbon accumulation capability of two typical tidal wetland soils in Chongming Dongtan, China

We measured organic carbon input and content of soil in two wetland areas of Chongming Dongtan (Yangtze River Estuary) to evaluate variability in organic carbon accumulation capability in di erent wetland soils. Observed di erences were investigated based on the microbial activity and environmental factors of the soil at the two sites. Results showed that the organic carbon content of wetland soil vegetated with Phragmites australis (site A) was markedly lower than that with P. australis and Spartina alterniflora (site B). Sites di erences were due to higher microbial activity at site A, which led to higher soil respiration intensity and greater carbon outputs. This indicated that the capability of organic carbon accumulation of the site B soils was greater than at site A. In addition, petroleum pollution and soil salinity were di erent in the two wetland soils. After bio-remediation, the soil petroleum pollution at site B was reduced to a similar level of site A. However, the culturable microbial biomass and enzyme activity in the remediated soils were also lower than at site A. These results indicated that greater petroleum pollution at site B did not markedly inhibit soil microbial activity. Therefore, di erences in vegetation type and soil salinity were the primary factors responsible for the variation in microbial activity, organic carbon output and organic carbon accumulation capability between site A and site B.     

理化性质对土壤吸附-解吸苄嘧磺隆的影响

为探讨土壤理化性质对其吸附-解吸BSM(苄嘧磺隆)的影响,采用批量平衡法研究了采自我国东南沿海和中部14个省区的21个土壤样品对BSM的吸附-解吸行为,以及BSM吸附-解吸行为与土壤pH、w(有机质)、w(TN)、w(黏粒)、CEC(阳离子交换量)等理化性质的关系. 结果表明:BSM在土壤中的等温吸附线可用Freundlich方程进行拟合,不同土壤对BSM的吸附强度差异较大,K_f (Freundlich常数)介于0.52~24.05之间. 土壤pH、w(有机质)是影响BSM吸附的主要因素,二者对K_f的解释率为58.1%;土壤对BSM的吸附还受w(TN)、w(黏粒)等的影响. 土壤对BSM的吸附-解吸存在滞后现象,HI(迟滞系数)与土壤pH呈极显著负相关,与w(黏粒)呈显著正相关,其中土壤pH对HI的解释率为33.0%. 吸附平衡溶液pH与K_d (分配系数)呈极显著负相关,对其进行调节可显著改变土壤对BSM的分配能力.      

氯酚污染土壤的生物强化修复及其微生物种群动态变化的分子生物学监测

在氯酚污染的土壤中接种氯酚降解菌,研究了受污染土壤的生物强化修复.利用传统的微生物计数方法和现代分子生物学手段,研究了生物强化修复过程中微生物种群的动态变化情况.在受氯酚污染的土壤样品中,以氯酚为唯一碳源和能源,分离出了多株对氯酚具有较高降解能力的微生物,利用16S rDNA序列分析方法对部分微生物进行了种属鉴定.土壤中存在的土著的氯酚降解菌可以对低含量的氯酚(100mg·g-1)进行降解;但是当土壤中氯酚含量较高(500 mg·g-1)时,土著微生物的降解能力受到限制,这可能是高浓度的氯酚对土著的氯酚降解菌会产生毒性作用.接种外来微生物后,土壤中可以培养的氯酚降解菌的总数从开始的106CFU·g-1增加到108CFU·g-1,并且,在氯酚含量为100 mg·g-1的土壤样品中,微生物数目的增加比在氯酚含量为500 mg·g-1土壤样品中更快.这表明接种的外来微生物可以在土壤中很好地生长繁殖,有效地促进土壤中氯酚的生物降解.接种外来微生物可以减轻土壤中氯酚对土著微生物初期产生的不利影响.土壤中的氯酚可能会改变微生物种群结构.DGGE分析结果表明,在未受氯酚污染和受氯酚污染的土壤样品中,存在一些共同的DNA谱带,但谱带强度有明显的差异.在受污染的土壤中接种外来微生物进行生物强化,可以促进污染物的生物降解过程,是生物修复过程中的一种重要手段,有着广泛的应用前景,将在我国受污染环境的生物修复中发挥重要作用.     

基于MiSeq测序分析酸性农作物土壤细菌群落结构与多样性

为分析酸性农田土壤中微生物群落结构,探寻酸化土壤的综合治理途径,以湖北恩施土家族苗族自治州利川市酸性农作物土壤为研究对象,应用Illumina MiSeq高通量测序技术,测定酸性土壤中总细菌和经驯化的可培养细菌的16S rRNA基因V3~V4变异区序列,确定不同农作物土壤中总细菌和可培养细菌的群落结构,并探讨土壤理化因子对土壤总细菌群落结构的影响.结果表明:白菜地、烟草地、山药地、草莓地、玉米地及莴苣地这6种农作物土壤中总细菌和可培养细菌在97%的相似水平下得到的OTUs（operational taxonomic units,操作分类单元）数量分别为4 008和97个.在门水平上,土壤总细菌中有12个门类的细菌相对丰度大于1%,Proteobacteria、Acidobacteria和Chloroflexi为优势菌门细菌;可培养细菌中仅有3个门类细菌相对丰度高于1%,即Firmicutes、Proteobacteria和Bacteroidetes.在OTU水平上,土壤总细菌沿pH梯度将6种土壤样品分为2类,即pH < 5.5的玉米地、山药地和莴苣地和pH>5.5的烟草地、白菜地和草莓地.此外,冗余分析（RDA）结果显示,Acidobacteria的相对丰度与pH呈正相关,Firmicutes和Roteobacter的相对丰度均与w（TN）、w（TP）、w（TC）呈正相关.系统进化树分析表明,相对丰度位于前30位的细菌与亚洲地区发现细菌的16S rRNA基因序列同源性较高.研究显示,Illumina MiSeq测序能够较为全面地解析酸性土壤中总细菌和可培养细菌的多样性,驯化过程极大地减少了细菌的种类;同时,发现细菌群落结构的相似性可能因样本来源的地理距离的增加而衰减.      

西安市春季生物气溶胶的分布特征和健康影响

西安春季经常出现大量飞絮,易造成空气污染并引发居民哮喘等健康风险.采集西安市春季不同观测点(交通样点和校园样点)生物气溶胶、 PM_2.5和飞絮样品,通过恒温培养和高通量测序等方法研究可培养生物气溶胶的浓度变化、粒径分布,PM_2.5和飞絮携带的微生物的来源、群落结构和健康影响.结果表明,可培养细菌浓度在交通样点高于校园样点(P=0.027);交通样点可培养细菌浓度为真菌的2.7倍,而校园样点可培养真菌浓度高于细菌(1.4倍).可培养细菌和真菌日内最高浓度均出现在08:00;可培养细菌粒径呈双峰分布,真菌为单峰分布.土壤和植被是大气微生物的主要来源(占比85.9%),变形菌门(Proteobacteria)是飞絮和PM_2.5中共有的、丰度最高的菌门,在飞絮中占比达到91.3%(交通样点)和99.1%(校园样点);在PM_2.5样品中放线菌门(Actinobacteria)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)、蓝藻门(Cyanobacteria)和异常球菌-栖热菌门(D...     

青岛近海生物气溶胶中可培养微生物浓度及群落多样性的季节变化

为了研究近海生物气溶胶中可培养微生物浓度和群落多样性,于2009年7月~2010年6月在青岛两个采样点连续采集生物气溶胶样品,分析了其中陆源细菌、海源细菌、陆源真菌和海源真菌的浓度,并计算了Shannon-Weiner指数、Simpson’s指数和Pielou指数.结果表明,陆源细菌和海源细菌月均浓度分别为12~436 CFU·m-3和25~561 CFU·m-3,陆源真菌和海源真菌月均浓度分别为0~817 CFU·m-3和11~1 346 CFU·m-3之间.陆源细菌、海源细菌、陆源真菌和海源真菌浓度在冬季月份较低,2月达到最低值,在春夏月份较高.海源微生物对总可培养类微生物的贡献高于陆源,平均占63%.可培养微生物物种数在17~102之间,与微生物浓度具有一定的相关性,但并未呈现出明显的季节变化.3种指数表明,生物气溶胶中陆源细菌、海源细菌、陆源真菌和海源真菌的群落结构在2月最简单,1月、11月和5月群落多样性较高,群落多样性与浓度的季节变化特征并不一致,而且不同类别的微生物群落存在季节和空间差异.     

梅雨期大学宿舍室内生物气溶胶浓度及粒径分布

大学宿舍室内生物气溶胶可通过空气传播,可能会危害学生身体健康.本研究调查了梅雨期大学宿舍室内生物气溶胶浓度和粒径分布特点,对其同空气颗粒物浓度、环境温度和湿度的Spearman相关性进行了研究,分析了学生活动对宿舍室内气溶胶的影响.结果表明,学生宿舍室内的细菌和真菌气溶胶平均浓度分别为(2 133±1 617)CFU·m~(-3)和(3 111±2 202)CFU·m~(-3),真菌气溶胶的浓度明显高于细菌.学生宿舍室内的PM1、PM_(2.5)、PM10与细菌气溶胶浓度呈负相关,与真菌气溶胶浓度呈显著负相关;PM_(2.5)与可吸入细菌气溶胶呈正相关,PM_(10)与可吸入真菌气溶胶呈正相关;环境温度与细菌和真菌气溶胶浓度呈正相关,环境相对湿度与细菌和真菌气溶胶浓度呈负相关.在下午,宿舍室内真菌气溶胶浓度显著增加,上午和下午生物气溶胶的粒径分布有差异.本研究结果将为评价高校学生宿舍室内空气质量提供基础数据.     

Evidence of rich microbial communities in the subsoil of a boreal acid sulphate soil conducive to greenhouse gas emissions

The largest areas of acid sulphate (AS) soils in Europe are located in Finland, where 67,000–130,000 ha of AS soils are in agricultural use. In addition to their acidifying effects on waters, AS soils might be a significant source of greenhouse gases. In this pilot research, carbon and nitrogen content and microbial activity were studied in an AS and a non-AS soil. Large carbon and nitrogen stocks (110 Mg C_org ha^?1 and 15 Mg N_tot ha^?1) as well as high substrate induced respiration (33 μg CO₂–C g^?1h^?1) were found in the C horizons of the AS soil but not in the non-AS soil. High microbial activity in these horizons of the AS soil was further confirmed by the measurement of dehydrogenase activity, basal respiration, the numbers of culturable bacterial cells, and the ratio of culturable to total numbers of cells. Still, the denitrifying enzyme activity was very low in the anaerobic horizons of the AS soil, indicating the prevalence of microbes other than denitrifiers. We suspect that the microbial community originated with the genesis of AS soil and has been supported by the large stocks of accumulated carbon and mineral nitrogen in the C horizons. If these permanently water-saturated subsoils are exposed to oxygen and their microbial activity consequently increases, large carbon and nitrogen stocks are likely to be mobilised, resulting in increased emission of greenhouse gases. Additional studies of boreal AS soils are needed to assess their potential contribution to increases in greenhouse gas fluxes at the local, regional, and global scales.     

纳木错夏季酵母菌多样性及其影响因素

以纳木错湖水为研究对象,采用膜过滤平置培养法分离纯化酵母菌,并结合ITS区域序列分析与经典分类法对酵母菌菌株进行鉴定,运用生物信息学和统计学方法分析水体可培养酵母菌的多样性及其与理化因子之间的相关关系.结果显示,从纳木错水体中分离出1067株酵母菌,分属于27个属45个种及2个潜在新分类单元,优势种为Vishniacozyma victoriae和Naganishia adeliensis.NMDS分析显示,纳木错不同区域水体可培养酵母菌群落β多样性差异明显.Pearson相关性分析结果表明,酵母菌总丰度与pH值、电导率、总溶解固体量、盐度呈极显著负相关（P<0.01）,与总氮、氨氮呈显著正相关（P<0.05）;物种数、Shannon-Wiener多样性指数、Simpson多样性指数均与总磷呈显著负相关（P<0.05）.冗余分析显示,pH值是影响纳木错水体酵母菌种群分布的主要理化因子.综上,纳木错水体酵母菌资源比较丰富且存在明显的空间异质性,水体理化因子对纳木错水体可培养酵母菌的分布有较大的影响.