Soil fungistasis and its relations to soil microbial composition and diversity: a case study of a series of soils with different fungistasis

Fungistasis is one of the important approaches to control soil-borne plant pathogens.Some hypotheses about the mechanisms for soil fungistasis had been established,which mainly focused on the soil bacterial community composition,structure,diversity as well as function.In this study,the bacterial community composition and diversity of a series of soils treated by autoclaving,which coming from the same original soil sample and showing gradient fungistasis to the target soil-borne pathogen fungi Fusarium gr...     

底泥中红霉素耐受菌群的多样性分析

为了正确评估抗生素残留的环境风险,了解长期受低浓度红霉素污染条件下,水体底泥中红霉素耐受菌群结构的变化特点,采用传统的微生物培养法和分子生物学方法对长期受低浓度红霉素污染的水体底泥中红霉素耐受菌群结构的多样性进行了分析.结果表明:采用传统的培养方法,从底泥中可分离筛选出3株对红霉素有耐受能力的菌株,根据其形态学特征及16S rDNA序列分析,初步鉴定为赖氨酸芽孢杆菌(Lysinibacillussp.)、土壤芽孢杆菌(Solibacillus silvestris)以及蜡样芽孢杆菌(Bacillus cereus),其中敏感菌蜡样芽孢杆菌经低浓度红霉素诱导对红霉素表现出一定的耐药性.进一步构建底泥耐药菌群16S rDNA克隆文库发现,底泥中红霉素耐受菌群可分为三大类群,其中未获培养的细菌(Uncultured bacterium)在整个文库中比例最大,占65.06%,其次为芽孢杆菌纲(Bacilli)和梭菌纲(Clostridia),分别占文库比例33.73%和1.20%.文库中可培养的耐药菌优势类群为芽孢杆菌纲,与传统培养方法得到的结果相一致.上述研究表明,在长期受低浓度红霉素污染的环境中,红霉素耐药菌的存在具有一定的广泛性和潜在性,将可能威胁人类健康和生态系统,应当重视其生态风险评价与管理.     

重金属复合污染农田土壤的微生物群落遗传多样性研究

采集了浙江省富阳市环山乡某冶炼厂小高炉附近受铜、锌、铅、镉不同程度复合污染的4个农田土壤样品，首先扩增土壤总DNA中的16S rDNA，然后进行变性梯度凝胶电泳(Denaturing Gradient Gel Electrophoresis)，分析了长期受重金属复合污染的农田土壤的微生物群落遗传多样性变化．结果表明，不同程度的重金属复合污染明显改变了农田土壤的微生物群落遗传多样性，但与多样性的改变不是简单的负相关关系，最大的多样性指数出现在中等污染程度的土壤中．     

我国东北典型河流冰封期细菌多样性的研究——以松花江为例

在我国东北松花江冰封期时采集了该河流域5个监测断面的河水样本,并分别构建16S rDNA克隆文库,通过16S rDNA序列的系统发育分析,对水样中细菌群落结构和种群多样性进行了研究.试验结果表明,5个采样点的水样pH都呈弱酸性,并且都有不同程度的多环芳烃(PAHs)污染,其中,B(九站)采样点污染最为严重.5个样品中检测到的共同细菌种类有5个:β-变形菌纲(Betaproteobacteria)、γ-变形菌纲(Gammaproteobacteria)、放线菌门(Actinobacteria)、蓝细菌门(Cyanobacteria)和拟杆菌门(Bacteroidetes).5个河水样品中的细菌与许多已知降解菌的亲缘关系较近,并以能降解多环芳烃类有机污染物的微生物种类居多,且在5个样品中均发现了指示河流富营养化的菌种,表明该河流存在普遍的富营养化趋势,特别是D、E段(佳木斯上和佳木斯下)比较严重.     

Soil enzymatic activities and microbial community structure with di erent application rates of Cd and Pb

This study focused on the changes of soil microbial diversity and potential inhibitory effects of heavy metals on soil enzymatic activities at different application rates of Cd andor Pb. The soil used for experiments was collected from Beijing and classified as endoaquepts. Pots containing 500 g of the soil with different Cd andor Pb application rates were incubated for a period of 0, 2, 9, 12 weeks in a glasshouse and the soil samples were analyzed for individual enzymes, including catalase, alkaline phosphatase and dehydrogenase, and the changes of microbial community structure. Results showed that heavy metals slightly inhibited the enzymatic activities in all the samples spiked with heavy metals. The extent of inhibition increased significantly with increasing level of heavy metals, and varied with the incubation periods. The soil bacterial community structure, as determined by polymerase chain reaction-denaturing gradient gel electrophoresis techniques, was different in the contaminated samples as compared to the control. The highest community change was observed in the samples amended with high level of Cd. Positive correlations were observed among the three enzymatic activities, but negative correlations were found between the amounts of the heavy metals and the enzymatic activities.     

百草枯对巨桉人工幼林土壤细菌多样性的影响

为了解百草枯对土壤微生物多样性的影响过程和时效,在施加百草枯后第0、1、2、4、8、15、31d动态采集四川盆地典型巨桉人工幼林表层土壤,采用PCR-DGGE方法研究了细菌群落多样性特征.结果表明,施加百草枯后第1d土壤细菌丰富度显著降低,但在第2d明显增加,随后在第4d和第8d出现一个降低的过程,直至第15d降至最低点,在第31d又显著增加.施用百草枯后明显降低了土壤细菌群落Shannon-Wiener指数,但增加了Simpson指数,表明百草枯的施加可使部分细菌减少或丧失,土壤细菌群落结构表现出较高的优势度和较低的丰富度.通过对优势条带的克隆测序,鞘脂杆菌科(Sphingobacteriaceae)和酸杆菌纲(Acidobacteria)普遍存在于施加百草枯前后的不同阶段,而施加百草枯后第1d伯克氏菌目(Burkholderiales)和γ-变形菌纲(Gamma-proteobacteria)条带消失,随后均在第2、4和8d出现,但15d后伯克氏菌目、α-变形菌纲(Alpha-proteobacteria)和γ-变形菌纲条带消失,第31dγ-变形菌纲条带仍然缺失.这些结果为更清晰地认识百草枯对土壤微生物的影响提供了基础数据.     

限制性片段长度多态性分析(ARDRA)方法对重金属污染土壤中细菌群落多样性的研究

限制性片段长度多态性分析(ARDRA)是用限制性内切酶消化扩增后的细菌16S rDNA,通过凝胶电泳分析微生物种群多样性的分子标记技术,该技术在微生物生态学领域有着广泛的应用.实验采用2种途径评价了这种方法应用于研究土壤中细菌种群多样性的可行性.通过对未污染土壤细菌16S rDNA的克隆,获得了经内切酶HaeⅢ消化的不同16S rDNA的ARDRA类型,并对测序的19个克隆子建立了系统发育树.此外,还对不同Cd和Pb污染水平的土壤微生物进行了群落水平上的ARDRA分析.结果表明,5 mg·kg-1 Cd和500 mg·kg-1 Pb污染对微生物群落组成有一定影响,但此范围内的重金属含量对微生物群落多样性没有相关性影响.     

16S rDNA 克隆文库法分析Biostyr 曝气生物滤池处理城市污水的细菌多样性研究

采用分子生物学手段16SrDNA克隆文库方法,对第三代生物膜法代表工艺Biostyr曝气生物滤池（BAF）中滤料表面细菌进行了多样性研究.从16SrDNA克隆文库中随机挑选了50个克隆子进行序列测定（约1.5kb）,对测序结果进行了BLAST对比.结果表明,BiostyrBAF系统中的细菌群落具有高度多样性,有41个克...     

Alteration of microbial properties and community structure in soils exposed to napropamide

The effect of pesticide napropamide (N,N-diethyl-2-(1-naphthalenyloxy) propanamide) on soil microorganisms for long-term (56 d) was assessed by monitoring changes in soil microbial biological responses. Soils were treated with napropamide at 0, 2, 10, 20, 40, and 80 mg/kg soil and sampled at intervals of 1, 3, 7, 14, 28, 42, and 56 d. The average microbial biomass C declined in napropamide-treated soils as compared to control. The same trend was observed on microbial biomass N after napropamide application.We also determined the basal soil respiration (BSR) and observed a high level in soils treated with napropamide during the first 7 d of experiment. But with the passage of incubation time, BSR with napropamide decreased relatively to control. Application of napropamide at 2–80 mg/kg soil had inhibitory e ects on the activity of urease and invertase. Activity of catalase was enhanced during the initial 7 d of napropamide application, but soon recovered to the basal level. The depressed enzyme activities might be due to the toxicity of napropamide to the soil microbial populations. To further understand the e ect of napropamide on microbial communities, a PCRDGGE- based experiment and cluster analysis of 16S rDNA community profiles were performed. Our analysis revealed an apparent di erence in bacterial-community composition between the napropamide treatments and control. Addition of napropamide apparently increased the number of bands during the 7–14 d of incubation. These results imply that napropamide-induced toxicity was responsible for the disturbance of the microbial populations in soil.     

稻草还田对土壤微生物群落功能多样性的影响

为了探讨稻草还田的微生物学过程与效应,借助平板涂抹法和BIOLOG检测法,比较研究了免耕条件下3种不同稻草还田量(33%、67%和100%,以稻草不还田土壤为对照)对晚稻田土壤微生物群落功能多样性的影响.结果表明:①土壤细菌数量差异显著,以67%稻草还田处理为最高,稻草不还田处理最低,稻草还田提高了土壤细菌数量;②碳源平均颜色变化率(AWCD法)在培养早期各处理间的差异不大,但随着培养时间的延长,67%和100%稻草还田处理土壤微生物的AWCD值显著大于对照和33%稻草还田处理组;③土壤微生物代谢多样性指数(丰富度和多样性)在3种稻草还田量处理土壤中也表现出明显差异,67%和100%稻草还田处理的土壤中微生物功能多样性显著大于33%稻草还田处理和对照;④67%和100%稻草还田处理显著改善了土壤微生物的功能多样性.以67%稻草还田处理改善土壤微生物群落结构和功能的效果最为显著.     

Archaeal community structure along a gradient of petroleum contamination in saline-alkali soil

The impact of petroleum on archaeal community in salinealkali soils was investigated, which will expand the knowledge of the archaeal population involved in the natural attenuation of hydrocarbons in extreme environments.     

Effect of heavy metals on soil microbial activity and diversity in a reclaimed mining wasteland of red soil area

The microbial biomass, basal respiration and substrate utilization pattern in copper mining wasteland of red soil area, southern China, were investigated. The results indicated that soil microflora were obviously different compared with that of the non-mine soil. Microbial biomass and basal respiration were negatively affected by the elevated heavy metal levels. Two important microbial ecophysiological parameters, namely, the ratio of microbial biomass C（ Cmic ）/organic C（ Corg ） and metabolic quotient（qCO2 ） were closely correlated to heavy metal stress. There was a significant decrease in the Cmic/Corg ratio and an increase in the metabolic quotient with increasing metal concentration. Multivariate analysis of Biolog data for sole carbon source utilization pattern demonstrated that heavy metal pollution had a significant impact on microbial community structure and functional diversity. All the results showed that soil microbiological parameters had great potential to become the early sensitive, effective and liable indicators of the stresses or perturbations in soils of mining ecosystems.     

Bacterial diversity and distribution in the southeast edge of the Tengger Desert and their correlation with soil enzyme activities

The nature of microbial communities and their relation to enzyme activities in desert soils is a neglected area of investigation. To address this, the bacterial diversity and distribution and soil physico-chemical factors were investigated in the soil crust, the soil beneath the crust and rhizosphere soil at the southeast edge of the Tengger Desert, using the denaturing gradient gel electrophoresis of 16S rRNA genes amplified by the polymerase chain reaction. Phylogenetic analysis of the sequenced DGGE bands revealed a great diversity of bacteria. The Proteobacteria, consisting of the α, β, and γ subdivisions, were clearly the dominant group at all depths and in rhizosphere soil. Analysis of the enzyme activities indicated that the rhizosphere soil of Caragana korshinskii exhibited the highest protease and polyphenol oxidase activities, and in the soil crust there were increased activities of catalase, urease, dehydrogenase and sucrase. The bacterial community abundance closely correlated with soil enzyme activities in different soils. The presence of Cyanobacteria correlated with significant increases in protease, catalase and sucrase in the soil crust, and increased urease in the rhizosphere soil of Artemisia ordosica. The occurrence of Acidobacteria was associated with significant increases in urease, dehydrogenase, and sucrase in the rhizosphere soil of C. korshinski. The presence of γ-Proteobacteria correlated with a significant increase in polyphenol oxidase in the rhizosphere soil of A. ordosica. The study indicated a close relationship between the soil bacterial community and soil enzymes, suggesting the necessity of further investigations into bacterial function in this desert ecosystem.     

Screening and degrading characteristics and community structure of a high molecular weight polycyclic aromatic hydrocarbon-degrading bacterial consortium from contaminated soil

Inoculation with effcient microbes had been proved to be the most important way for the bioremediation of polluted environments. For the treatment of abandoned site of Beijing Coking Chemical Plant contaminated with high level of high-molecular-weight polycyclic aromatic hydrocarbons(HMW-PAHs) ,a bacterial consortium capable of degrading HMW-PAHs,designated 1-18-1,was enriched and screened from HMW-PAHs contaminated soil.Its degrading ability was analyzed by high performance liquid chromatography(HPLC) ,and the community structure was investigated by construction and analyses of the 16S rRNA gene clone libraries(A,B and F) at different transfers.The results indicated that 1-18-1 was able to utilize pyrene,fluoranthene and benzoapyrene as sole carbon and energy source for growth.The degradation rate of pyrene and fluoranthene reached 82.8%and 96.2%after incubation for 8 days at 30°C,respectively;while the degradation rate of benzoapyrene was only 65.1%after incubation for 28 days at 30°C. Totally,108,100 and 100 valid clones were randomly selected and sequenced from the libraries A,B,and F.Phylogenetic analyses showed that all the clones could be divided into 5 groups,Bacteroidetes,α-Proteobacteria,Actinobacteria,β-Proteobacteria andγ-Proteobacteria.Sequence similarity analyses showed total 39 operational taxonomic units(OTUs) in the libraries.The predominant bacterial groups wereα-Proteobacteria(19 OTUs,48.7%) ,γ-Proteobacteria(9 OTUs,23.1%) andβ-Proteobacteria(8 OTUs,20.5%) . During the transfer process,the proportions ofα-Proteobacteria andβ-Proteobacteria increased greatly(from 47%to 93%) ,while γ-Proteobacteria decreased from 32%(library A) to 6%(library F) ;and Bacteroidetes group disappeared in libraries B and F.     

Effect of lime application on microbial community in acidic tea orchard soils in comparison with those in wasteland and forest soils

Lime application is a conventional technology to control acidification in tea orchard soils. We investigated the e ect of lime application on soil microbial community diversity in the soils of three tea orchards, wasteland and forest. The BIOLOG data showed that both the average well color development of all carbon sources and the functional diversity index increased with the liming rate in the tea orchards and the forest, but decreased in the wasteland. The phospholipid fatty acid (PLFA) analysis showed that the structural diversity index of soil microbial community increased with the liming rate in all the tea orchards, the wasteland and the forest. Lime application also increased the soil-bacterial PLFA content in all the soils. Soil fungal and actinomycete PLFAs in the tea orchards showed an increasing trend from 0 to 3.2 g CaCO3/kg application and then a decreasing trend from 3.2 to 6.4 g CaCO3/kg application. The principal component analysis of BIOLOG and PLFA data suggested that lime application had a significant e ect on soil microbial community structure, and land use had a greater e ect on soil microbial community structure compared to lime application.     

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...     

Effects of vegetation type on soil microbial community structure and catabolic diversity assessed by polyphasic methods in North China

Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community.In order to understand the effects of vegetation type on the characteristics of soil microbial communities,the soil microbial communities were assessed by plate counts,phospholipid fatty acid (PLFA) and Biolog microplate techniques in five plant communities,i.e.,soybean field (SF),artificial turf (AT),artificial shrub (AS),natural shrub (NS),and maize field (MF) in Jinan,Shandong Province,North China.The results showed that plant diversity had little discernible effect on microbial biomass but a positive impact on the evenness of utilized substrates in Biolog microplate.Legumes could significantly enhance the number of cultural microorganisms,microbial biomass,and community catabolic diversity.Except for SF dominated by legumes,the biomass of fungi and the catabolic diversity of microbial community were higher in less disturbed soil beneath NS than in frequently disturbed soils beneath the other vegetation types.These results confirmed that high number of plant species,legumes,and natural vegetation types tend to support soil microbial communities with higher function.The present study also found a significant correlation between the number of cultured bacteria and catabolic diversity of the bacterial community.Different research methods led to varied results in this study.The combination of several approaches is recommended for accurately describing the characteristics of microbial communities in many respects.     

序批式接触氧化反应器中细菌多样性及其功能

采用分子生物学手段,通过构建16S rDNA基因文库,对新型剩余污泥减量化处理系统——序批式生物砾间接触氧化反应器中细菌多样性进行了系统发育分析,并讨论了多种细菌共存对剩余污泥减量化的贡献.共有72个克隆子用于细菌系统发育分析. 结果表明:填料表面附着细菌与孔隙内细菌由变型菌属、噬纤维菌-屈挠杆菌-拟杆菌组(CFB)、硝化杆菌科、低G+C革兰氏阳性细菌、高G+C革兰氏阳性细菌、疣微菌科和绿菌科等七大类细菌组成. 其中,优势菌群分别是以兼具呼吸/发酵代谢方式的β变形菌纲(分别占生物膜和内泥中克隆子总量的18%和35%)和δ变形菌纲,以及以呼吸/发酵为主要代谢方式的CFB(分别占克隆子总量的24%和23%). 多种细菌对剩余污泥减量化的主要功能可归纳为能量解偶联、共代谢作用、生物溶胞作用和慢性生长种群的影响.      

闽江河口互花米草海向入侵对湿地土壤nirS型反硝化微生物群落结构及多样性的影响

2020年秋季,在闽江河口鳝鱼滩东部的互花米草分布区,由陆向海方向选择互花米草海向入侵前的光滩(MF)、入侵1～2年的互花米草湿地(SAN)和入侵6～7年的互花米草湿地(SA)为研究对象.基于高通量测序技术,探讨了互花米草海向入侵对土壤nir S型反硝化微生物群落结构及多样性的影响.结果表明,变形菌门(Proteobacteria)均是互花米草不同入侵阶段土壤中nir S型反硝化微生物的优势门(90.41%～97.36%),其次是厚壁菌门(Firmicutes)和放线菌门(Actinobacteria),三者在SAN和MF土壤中的丰度均与SA存在显著差异(p<0.05).不同入侵阶段土壤中共有的nir S型反硝化细菌属为假单胞菌属(Pseudomonas)、芽孢杆菌属(Bacillus)、偶氮弧菌属(Azoarcus)、陶厄氏菌属(Thauera)、Sulfurifustis属、副球菌属(Paracoccus)、鲁杰氏菌属(Ruegeria)、红肠命菌属(Rubrivivax)、趋磁螺菌属(Magnetospirillum)和福格斯氏菌属(Vogesella),其中,假单胞菌属是...     

引调水河道氮的迁移转化及微生物群落结构特征——以望虞河为例

以引江济太调水工程-望虞河为研究对象,探究引调水河道氮素的迁移转化规律及微生物群落结构特征.于2020年10月、12月以及2021年1月在望虞河沿程布设监测点位并采集水样,分析其水体理化性质、氮的形态分布及含量、微生物群落结构变化特征.结果 表明:①硝酸盐氮是望虞河沿程水体中氮素的主要存在形态,占总氮浓度的75.3％～...