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1.
土壤健康是农业可持续发展的中心主题。土壤微生物参与土壤生态功能、环境功能和免疫功能协同驱动土壤生命系统运转，是维持土壤健康的核心与关键。了解不同微生物介导的土壤健康调控机制对有效利用这些核心微生物维持和改善土壤健康至关重要。本文围绕微生物参与调节土壤碳循环、养分循环，改变土壤结构、抑制植物病虫害、污染控制等主要生物过程系统梳理了微生物在调控土壤健康中的重要作用，以及微生物作为土壤健康的敏感指标对土壤健康的指示与预警作用。强调未来应加强驱动土壤健康特定功能以及多个生物过程的核心微生物组信息数据库挖掘、构建与生产应用研究，为定向利用微生物改善农业土壤生态系统功能、维持土壤健康以及保障土壤可持续发展提供科学依据。 相似文献
2.
Chen YP Tseng CP Liaw LL Wang CL Chen IC Wu WJ Wu MD Yuan GF 《Journal of agricultural and food chemistry》2008,56(14):5639-5646
Monacolin K is a secondary metabolite synthesized by polyketide synthases (PKS) from Monascus, and it has the same structure as lovastatin, which is mainly produced by Aspergillus terreus. In the present study, a bacterial artificial chromosome (BAC) clone, mps01, was screened from the BAC library constructed from Monascus pilosus BCRC38072 genomic DNA. The putative monacolin K biosynthetic gene cluster was found within a 42 kb region in the mps01 clone. The deduced amino acid sequences encoded by the nine genes designated as mokA- mokI, which share over 54% similarity with the lovastatin biosynthetic gene cluster in A. terreus, were assumed to be involved in monacolin K biosynthesis. A gene disruption construct designed to replace the central part of mokA, a polyketide synthase gene, in wild-type M. pilosus BCRC38072 with a hygromycin B resistance gene through homologous recombination, resulted in a mokA-disrupted strain. The disruptant did not produce monacolin K, indicating that mokA encoded the PKS responsible for monacolin K biosynthesis in M. pilosus BCRC38072. 相似文献
3.
分形理论在土壤肥力研究中的应用与前景 总被引：3，自引：2，他引：1
分形理论的提出对于定量描述复杂的、高度不规则的系统特征与机理提供了方法.本文从土壤腐殖质、土壤微生物、土壤团聚体等方面回顾了分形理论在土壤肥力研究中的主要结果:土壤腐殖质胶体在不同条件下形成不同分形特征的聚合物;同一种微生物可能形成具有不同分形特征的结构;土壤中的有机无机胶体在不同条件下凝聚成不同的团聚体,从而形成不同的土壤结构并对其肥力功能产生影响.我们认为分形理论在探索土壤的形成过程和肥力功能上将具有重要的应用前景:如团粒结构体的形成可能是由土壤胶体分形凝聚而成;土壤中的活性有机质有逐渐老化的现象,可能和腐殖质胶体由结构疏松的分形结构向普通团聚体过渡的过程有关;土壤微生物在不同微环境下具有不同的分形特征,可以推测在各种土壤过程(包括物理、化学以及生物化学过程)中它们的功能也可能是不一样的.此外,土壤结构的开放程度决定孔隙、水分以及空气的分布,从而决定了微生物的生存空间.所以土壤结构体对微生物空间分布的影响也是将来该领域值得研究的内容之一. 相似文献
4.
植物内生菌影响土壤微生物区系的研究进展 总被引：1，自引：0，他引：1
土壤微生物区系是土壤生态环境的重要组分,其结构的稳定性对作物的健康生长至关重要。本文重点综述了植物内生菌对土壤微生物区系的调节作用,调节机制及潜在应用,指出了植物内生菌影响土壤微生物区系研究中出现的问题。一些植物内生菌不仅对植物生长有益,还可以显著改善土壤微生物区系,主要表现在对土壤微生物种类及数量、微生物生物量、酶活性及相关酶基因表达的影响,这可能是内生菌在土壤中和植物体内引发的多种效应的综合。植物内生菌可以在土壤中作为腐生菌与土壤微生物存在生态位竞争,通过产生某些抗菌活性物质和有机酸影响土壤微生物生长,通过降解复杂有机物如木质素、酚类化感物质等调节微生物区系,并吸收和转运重金属降低其对土壤微生物区系的危害等等。最后提出了今后的研究方向。 相似文献
5.
土壤质量生物学指标研究进展 总被引：52，自引：7，他引：52
本文对近年土壤微生物、土壤酶活性和土壤动物等土壤质量生物学指标研究成果进行了综合评述。土壤微生物是土壤有机组分和生态系统中最活跃的部分,被认为是最敏感的土壤质量生物学指标:微生物生物量代表参与调控土壤中能量和养分循环及有机物质转化所对应微生物的数量,但须结合多样性研究以弥补其无法反映土壤微生物组成和区系变化的缺陷;微生物群落组成和多样性动态反映土壤中生物类群的多变性和土壤质量在微生物数量和功能上的差异;土壤微生物活性体现在土壤微生物商、微生物呼吸和代谢商等方面,应考虑生物量大小与微生物种群活性间的相关关系以反映微生物种群内的差异。土壤酶活性具有极高时效性,在较短时间内就能反映出土壤质量的变化。土壤动物通常以种类的组成和数量,土壤动物区系的相对丰度、多样性或活性作为评价土壤生物质量的敏感指标。与土壤理化指标相比,土壤生物学指标更能对土壤质量的变化做出灵敏迅速的响应,因而被广泛地用于评价土壤质量。 相似文献
6.
植物-土壤反馈效应及农田生产特点决定了农田土壤生产力的不可持续性,因而必须采用适当的措施方可保持地力常新。施用化肥解决了农田土壤的养分贫化问题,极大地提高了作物产量,但激发了土传病原生物的活性,作物土传病频发成为制约集约化农业可持续发展的瓶颈问题。现有的研究成果表明,地上生物多样性与土壤微生物多样性紧密联系,植物提供的有机物质是连接二者的物质基础。单一作物种植的集约化农业提供给土壤微生物可利用的有机物质来源单一,导致土壤微生物多样性下降,削弱对土传病原生物致病性的抑制作用。本文提出,在作物生长过程中添加土壤有益微生物偏好利用的有机物质,激活土壤有益微生物,可能是维持集约化农业土壤生物健康,抑制作物土传病的有效途径。为此,有必要开展各种土壤微生物偏好利用的有机物质以及作物生长过程中如何施用有机物质的方法。 相似文献
7.
8.
9.
Invertebrate control of soil organic matter stability 总被引：17，自引：0，他引：17
V. Wolters 《Biology and Fertility of Soils》2000,31(1):1-19
The control of soil organic matter (SOM) stability by soil invertebrates is evaluated in terms of their impact on the inherent
recalcitrance, accessibility to microorganisms, and interaction with stabilizing substances of organic compounds. Present
knowledge on internal (ingestion and associated transformations) and external (defecation, constructions) control mechanisms
of soil invertebrates is also reviewed. Soil animals contribute to the stabilization and destabilization of SOM by simultaneously
affecting chemical, physical, and microbial processes over several orders of magnitude. A very important aspect of this is
that invertebrates at higher trophic levels create feedback mechanisms that modify the spatio-temporal framework in which
the micro-food web affects SOM stability. Quantification of non-trophic and indirect effects is thus essential in order to
understand the long-term effects of soil biota on SOM turnover. It is hypothesized that the activities of invertebrates which
lead to an increase in SOM stability partly evolved as an adaptation to the need for increasing the suitability of their soil
habitat. Several gaps in knowledge are identified: food selection and associated changes in C pools, differential effects
on SOM turnover, specific associations with microorganisms, effects on dissolution and desorption reactions, humus-forming
and humus-degrading processes in gut and faeces, and the modification of invertebrate effects by environmental variables.
Future studies must not be confined merely to a mechanistic analysis of invertebrate control of SOM stability, but also pay
considerable attention to the functional and evolutionary aspects of animal diversity in soil. This alone will allow an integration
of biological expertise in order to develop new strategies of soil management which can be applied under a variety of environmental
conditions.
Received: 6 April 1999 相似文献
10.
G. Pietramellara J. Ascher F. Borgogni M. T. Ceccherini G. Guerri P. Nannipieri 《Biology and Fertility of Soils》2009,45(3):219-235
The review discusses origin, state and function of extracellular DNA in soils and sediments. Extracellular DNA can be released
from prokaryotic and eukaryotic cells and can be protected against nuclease degradation by its adsorption on soil colloids
and sand particles. Laboratory experiments have shown that DNA adsorbed by colloids and sand particles can be taken up by
prokaryotic competent cells and be involved in natural transformation. Most of these experiments have been carried out under
artificial conditions with pure DNA molecules and pure adsorbing matrices, but in soils and sediments, pure surface-reactive
colloids are not present and DNA is present with other cellular components (wall debris, proteins, lipids, RNA, etc.) especially
if released after cell lysis. The presence of inorganic compounds and organic molecules on both soil particles and DNA molecules
can influence the DNA adsorption, degradation and transformation of competent cells. Extracellular DNA can be used as C, N
and P sources by heterotrophic microorganisms and plays a significant role in bacterial biofilm formation. The nucleotides
and nucleosides originated from the degradation of extracellular DNA can be re-assimilated by soil microorganisms. Extracellular
DNA in soil can be leached and moved by water through the soil profile by capillarity. In this way, the extracellular DNA
secreted by a cell can reach a competent bacterial cell far from the donor cell. Finally, the characterisation of extracellular
DNA can integrate information on the composition of the microbial community of soil and sediments obtained by analysing intracellular
DNA. 相似文献
11.
氧化亚氮（N2O）是主要温室气体之一,土壤是N2O的重要排放源,其排放主要受N2O产生和还原的功能微生物影响。土壤团聚体是由原生颗粒（砂、粉、黏粒）、胶结物质和孔隙组成的土壤基本结构单元。土壤不同粒径团聚体之间因基质和孔隙差异形成特殊独立的微生境被视为N2O的生物化学反应器。在不同的微生境中,N2O产生和还原的功能微生物分布不同,因而土壤不同粒径团聚体N2O排放可能存在差异。目前在不同生态系统土壤全土N2O排放特征的报道较多,而对于不同粒径土壤团聚体N2O排放相对贡献尚不清楚、功能微生物分布还未知、N2O产生和还原热区尚未明确。本文综述了近年来国内外关于土壤团聚体对N2O产生和排放机制的研究,总结了土壤团聚体性状特征对N2O产生和还原的影响,阐述了不同粒径土壤团聚体对N2O排放影响的微生物学机制,进一步明确了今后需加强土壤团聚体N2O产生和还原的热区、环境因子阈值范围的确定、系列功能基因（酶）整体性的研究,以期为N2O模拟排放模型优化提供参考,为土壤N2O减排提供理论依据。 相似文献
12.
Terrestrial ecosystems experience simultaneous shifts in multiple drivers of global change, which can interactively affect various resources. The concept that different resources co-limit plant productivity has been well studied. However, co-limitation of soil microbial communities by multiple resources has not been as thoroughly investigated. Specifically, it is not clearly understood how microbial communities respond to shifts in multiple interacting resources such as water, temperature, and nitrogen (N), in the context of global change. To test the effects of these various resources on soil microorganisms, we established a field experiment with temperature and N manipulation in three grasslands of northern China, where there is a decrease in precipitation from east to west across the region. We found that microbial responses to temperature depended upon seasonal water regimes in these temperate steppes. When there was sufficient water present, warming had positive effects on soil microorganisms, suggesting an interaction between water and increases in temperature enhanced local microbial communities. When drought or alternating wet–dry stress occurred, warming had detrimental effects on soil microbial communities. Our results also provide clear evidence for serial co-limitation of microorganisms by water and N at the functional group and community levels, where water is a primary limiting factor and N addition positively affects soil microorganisms only when water is sufficient. We predict that future microbial responses to changes in temperature and N availability could be seasonal or exist only in non-drought years, and will strongly rely on future precipitation regimes. 相似文献
13.
The biodegradation of organic compounds in soil is a key process that has major implications for different ecosystem services such as soil fertility, air and water quality, and climate regulation. Due to the complexity of soil, the distributions of organic compounds and microorganisms are heterogeneous on sub-cm scales, and biodegradation is therefore partly controlled by the respective localizations of organic substrates and degraders. If they are not co-localized, transfer processes become crucial for the accessibility and availability of the substrate to degraders. This spatial interaction is still poorly understood, leading to poor predictions of organic compound dynamics in soils. The objectives of this work were to better understand how the mm-scale distribution of a model pesticide, 2,4-dichlorophenoxyacetic acid (2,4-D), and its degraders drives the fate of 2,4-D at the cm soil core scale. We constructed cm-scale soil cores combining sterilized and “natural” soil aggregates in which we controlled the initial distributions of 2,4-D and soil microorganisms with the following spatial distributions: i) a homogeneous distribution of microorganisms and 2,4-D at the core-scale, ii) a co-localized distribution of microorganisms and 2,4-D in a single spot (360 mm3) and iii) a disjoint localization of microorganisms and 2,4-D in 2 soil spots (360 mm3) separated by 2 cm. Two sets of experiments were performed: one used radiolabeled 14C-2,4-D to study the fate of 2,4-D, and the other used 12C-2,4-D to follow the dynamics of degraders. Microcosms were incubated at 20 °C and at field capacity (−31.6 kPa). At the core scale, we followed 2,4-D mineralization over time. On three dates, soil cores with microorganisms and 2,4-D localized in soil spots, were cut out in slices and then in 360 mm3 soil cubes. The individual soil cubes were then independently analysed for extractable and non-extractable 14C and for degraders (quantitative PCR of tfdA genes). Knowing the initial position of each soil cube allowed us to establish 3D maps of 2,4-D residues and degraders in soil. The results indicated that microorganisms and pesticide localizations in soil are major driving factors of i) pesticide biodegradation, by regulating the accessibility of 2,4-D to degrading microorganisms (by diffusion); and ii) the formation of non-extractable residues (NER). These results also emphasized the dominant role of microorganisms in the formation and localization of biogenic NER at a mm-scale. To conclude, these results demonstrate the importance of considering micro-scale processes to better understand the fate of pesticides and more generally of soil organic substrates at upper scales in soil and suggest that such spatial heterogeneity should not be neglected when predicting the fate of organic compounds in soils. 相似文献
14.
Discrimination of management effects on soil parameters by using principal component analysis: a multivariate analysis case study 总被引：1，自引：0，他引：1
M. M. Sena R. T. S. Frighetto P. J. Valarini H. Tokeshi R. J. Poppi 《Soil & Tillage Research》2002,67(2)
One of the major interests in soil analysis is the integrated evaluation of soil properties, which might be indicators of soil quality. Unsupervised methods of multivariate statistics are powerful tools for this integrated assessment and can help soil researchers to extract much more information from their data. A multivariate study was carried out in three farms from Guaíra, State of São Paulo, Brazil. Conventionally managed plots that intensively utilized pesticides and chemical fertilizers were compared with both non-disturbed forest areas and alternatively managed plots. The latter were under ecological farming employing effective microorganisms (EM) integrated with crop residues. Eight soil parameters were determined for each plot. Hierarchical cluster analysis (HCA) was used to verify the similarity among the plots. The multivariate approach of principal component analysis (PCA) allowed us to distinguish the areas as a function of the soil management and determine which are the most important parameters to characterize them. The forest areas presented higher microbial biomass with lower cellulolytics population than at cultivated sites. The alternative plots were characterized by higher microbial biomass and polysaccharide content with lower phosphate solubilizers and cellulolytics microorganisms colony counts than at the conventional areas. The higher observed levels of microbial biomass and polysaccharide content in the alternative areas can be attributed to the effects of the alternative soil amendment. All these effects can be clearer globally visualized with the aid of PCA, through the biplots. 相似文献
15.
土壤中存在能够威胁植物、动物和人体健康的病原细菌，消减这类土壤生物污染是一体化健康（One Health）的重要任务。因具有宿主细菌专一性强、侵染效率高、环境扰动性小等特性，噬菌体成为生态消减土壤病原细菌生物污染的重要手段。然而，由于土壤生物和非生物环境的复杂性，提升噬菌体消减土壤生物污染的效果和稳定性仍是当前的重大挑战。本文从噬菌体在土壤中的生存以及与病原细菌互作等过程着手，分析总结影响噬菌体阻控土壤生物污染效果和稳定性的主要因素：1）噬菌体的宿主细菌谱和种群数量，2）土壤病原细菌的多态性，3）影响噬菌体与土壤病原细菌互作的环境因素。通过构建高效噬菌体鸡尾酒、改善噬菌体产品形式和优化噬菌体施用技术等措施，建立提升阻控土壤生物污染效果和稳定性的策略，为完善土壤生物污染噬菌体疗法提供科学支撑。 相似文献
16.
Newly synthesized amino acids are the principle compounds created after inorganic nitrogen (N) is rapidly immobilized into microbial tissues. However, little is known about the mineralization kinetics of these newly synthesized amino acids compared to the amino acids originally present in the soil, and how substrate availability controls their mineralization. With 15N isotope tracing, the newly synthesized (15N-labeled) amino acids can be differentiated from the amino acids originally present (unlabeled) in soil, making it possible to evaluate the mineralization of the newly synthesized amino acids in tandem with the original amino acids. As amino acids can serve as both N and carbon (C) sources for microorganisms, the mineralization dynamics of amino acids may be manipulated by the availability of extraneous C and N. In this study, an aerobic 30-week intermittent leaching experiment was conducted, using glucose as C source and (14NH4)2SO4 as N source, following separate additions to soil. The newly synthesized amino acids were determined by an isotope-based high performance liquid chromatography/mass spectrometry (HPLC/MS). The newly synthesized soil amino acids mineralized faster than the original ones, which indicated more rapid cycling of N in the newly synthesized soil amino acids pool. Glucose addition significantly decreased the mineralization of both the newly synthesized and the original amino acids. However, when inorganic N was abundant, the newly synthesized amino acids decomposed rapidly, and preferentially as a C source and energy, while N addition inhibited the mineralization of the original amino acids in the soil. We conclude that the presence of readily degradable C (e.g. glucose) and inorganic N controls the mineralization of newly synthesized and original amino acid pools in soil differently, which is a crucial mechanism in adjusting the N supply and sequestration processes in soil ecosystems. 相似文献
17.
细菌胞外聚合物：基于土壤生态功能的视角 总被引：1，自引：0，他引：1
胞外聚合物（Extracellular Polymeric Substances,EPS）是微生物分泌到胞外环境的高分子量天然聚合物,其建立了生物膜结构和功能的完整性,是决定生物膜物理化学特性的关键组分。EPS是细菌生命的基础,为化学反应发生、养分捕获和抵抗环境胁迫提供了理想的环境。细菌分泌的EPS可以通过自身特性（如黏着性、吸湿性和络合性能等）实现土壤功能增益,如提高团聚体稳定性、增强保水持水能力,以及固持重金属等。本文梳理了细菌EPS的土壤生态功能,即充当细胞保护层、调节土壤生物响应、缓解土壤非生物胁迫和改善土壤整体功能,并探讨了土壤中细菌EPS未来研究的着眼点,以期呼吁更多学者关注细菌EPS及其在土壤生态系统中的功能。 相似文献
18.
The relationship between organic P status of 4 soils, 20 microorganisms isolated from these soils (2 bacteria and 3 fungi for each soil) and 13 dominant plant species of typical natural ecosystems of these soils was evaluated. The soils used were represented by two pairs with different ratios of monoester and diester P, and of DNA and other diester P. A Dystric Podzoluvisol and an alpine Umbric Leptosol were characterized by a relatively high proportion of diester P including much DNA P, while a Calcic Chernozem and subalpine Umbric Leptosol had lower proportion of diesters containing relatively less DNA P. The proportions of P compounds in bacteria and plants were very similar on average, based on the monoester to diester P ratio and on the proportions of different diesters in alkaline extract, whereas fungi contained considerably higher proportions of monoesters and polyphosphates, and a higher proportion of phospholipids in the diester fraction. The results showed that the Porg composition of NaOH extracts from different soils was more similar to the composition of extracts from different groups of microorganisms. There was no clear correspondence between soil and microbial diester P proportion and composition. A high proportion of polyphosphate P including pyrophosphate P in soil extracts indicates a significant contribution of fungal P compounds in the soil while the monoester to diester P ratio, and DNA to non-DNA P ratio should be used with caution to interpret the origins of soil Porg. The relative contributions of microorganisms and plants to monoester and diester P in soils is only partially understood. 相似文献
19.
《Journal of plant nutrition》2013,36(10-11):1889-1908
Abstract A number of iron oxides (hematite, goethite, lepidocrocite, maghemite, and magnetite) or short‐range ordered precipitates (ferrihydrite) may be found in soil environments, but in the rhizosphere the presence of organic ligands released by plants (exudates) or microorganisms promote the formation of ferrihydrite. Iron ions are liberated into soil solution by acidic weathering of minerals and then precipitated either locally or after translocation in soil environments. Humic and fulvic acids as well as organic substances produced by plants and microorganisms are involved in the weathering of primary minerals. Organic compounds play a very important role in the hydrolytic reactions of iron and on the formation, nature, surface properties, reactivity, and transformation of Fe oxides. Organic substances present in the rhizosphere interact with Fe promoting the formation of ferrihydrite and organo‐mineral complexes. The solubility of Fe precipitation products is usually low. However, the formation of soluble complexes of Fe(II) or Fe(III) with organic ligands, usually present in the rhizosphere increases the solubility of Fe‐oxides. Mobilization of Fe from Fe oxides by siderophores is of great importance in natural systems. They can form stable Fe(III) complexes (pK up to 32) and thus mobilize Fe from Fe(III) compounds. These higher Fe concentrations are important for the supply of Fe to plant roots which excrete organic acids at the soil–root interface. Iron oxides adsorb a wide variety of organic and inorganic anions and cations, which include natural organics, nutrients, and xenobiotics. There is competition between anions and cations for the surfaces of Fe‐oxides. Root exudates suppress phosphate or sulfate adsorption on Fe‐oxides. This is a mechanism by which plant roots mobilize adsorbed phosphate and improve their phosphate supply. Anions adsorption on iron oxides modify their dispersion/flocculation behavior and thus their mobility in the soil system. That can increase or decrease the possibility of contact between Fe‐oxides and organics or organisms able to dissolve them. 相似文献
20.
Microbiological and chemical changes in two arable soils after long-term sludge amendments 总被引：7，自引：0，他引：7
Sludge amendments increase the input of carbon and nutrients to the soil. However, the soil concentrations of heavy metals
and xenobiotica can also increase due to sludge amendments, with possible effects on soil microorganisms and soil fertility.
Therefore, we studied the effects on soil microorganisms and soil chemistry in two arable soils after 12 and 16 years of sewage
sludge amendment (0, 1 and 3 dry matter ha–1 year–1). The sludge amendments were combined with nitrogen addition at three rates according to crop requirements, and all combinations
were replicated 4 times, giving a total number of 36 parcels at each experimental site in a non-randomised block design. Univariate
data evaluation as well as principal component analysis and discriminant function analysis (DFA) were used to identify differences
between treatments in microbial and chemical parameters. The DFA showed that acid and alkaline phosphatase, potential ammonium
oxidation and total nitrogen were the most important parameters to discriminate between a priori defined groups of sludge
treatments. Among the heavy metals, copper showed the highest increase in soil concentration with sludge amendments, but this
increase was still not high enough to have a significant influence on the measured parameters. None of the xenobiotica investigated
was found in high soil concentrations. In conclusion, the present study showed that the sewage sludge affected several of
the biological and chemical parameters investigated. However, no severe negative effects on soil microorganisms were detected
at these moderate levels of sludge amendment.
Received: 3 December 1998 相似文献