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Functional diversity changes of microbial communities along a soil aquifer for reclaimed water recharge 总被引:1,自引:0,他引:1
The physiochemical and functional diversity of soil-attached microorganisms was investigated using a stabilized laboratory-scale soil aquifer treatment (SAT) system. In this system, reclaimed water after ozonation was used as the feed water, and 60% dissolved organic carbon was removed by the unsaturated vadose layer in 0.8?days. Soil biomass (volatile solids, phospholipid extraction) and functional diversity significantly decreased from the unsaturated vadose layer to the saturated aquifer, where they maintained the same level. Using principal components analysis based on substrate utilization pattern, the vadose layer soil sample was clearly separated from the saturated layer samples. Exceptionally, the oxidation rates of esters remained stable during SAT, indicating the purification potential on certain recalcitrant organic compounds in the saturated aquifer given an adequate retention time. Correlation analysis revealed that organic carbon was the key limiting factor for microbial biomass and activity, especially for tyrosine-like aromatic proteins and soluble microbial byproduct-like materials. 相似文献
3.
Masenya K. Thompson G. D. Tekere M. Makhalanyane T. P. Pierneef R. E. Rees D. J. G. 《Plant and Soil》2021,463(1-2):555-572
Plant and Soil - The rhizosphere microbiome substantially affects plant health, yet comparatively little is known regarding the foliar community dynamics. Here, we examine the relationship between... 相似文献
4.
PG Medihala JR Lawrence GD Swerhone DR Korber 《Canadian journal of microbiology》2012,58(9):1135-1151
Relatively little is known regarding the spatial variability of microbial communities in aquifers where well fouling is an issue. In this study 2 water wells were installed in an alluvial aquifer located adjacent to the North Saskatchewan River and an associated piezometer network developed to facilitate the study of microbial community structure, richness, and diversity. Carbon utilization data analysis revealed reduced microbial activity in waters collected close to the wells. Functional PCR and quantitative PCR analysis indicated spatial variability in the potential for iron-, sulphate-, and nitrate-reducing activity at all locations in the aquifer. Denaturing gradient gel electrophoresis analysis of aquifer water samples using principal components analyses indicated that the microbial community composition was spatially variable, and denaturing gradient gel electrophoresis sequence analysis revealed that bacteria belonging to the genera Acidovorax , Rhodobacter , and Sulfuricurvum were common throughout the aquifer. Shannon's richness (H') and Pielou's evenness (J') indices revealed a varied microbial diversity (H' = 1.488-2.274) and an even distribution of microbial communities within the aquifer (J' = 0.811-0.917). Overall, these analyses revealed that the aquifer's microbial community varied spatially in terms of composition, richness, and metabolic activity. Such information may facilitate the diagnosis, prevention, and management of fouling. 相似文献
5.
Van Nostrand JD Wu L Wu WM Huang Z Gentry TJ Deng Y Carley J Carroll S He Z Gu B Luo J Criddle CS Watson DB Jardine PM Marsh TL Tiedje JM Hazen TC Zhou J 《Applied and environmental microbiology》2011,77(11):3860-3869
A pilot-scale system was established to examine the feasibility of in situ U(VI) immobilization at a highly contaminated aquifer (U.S. DOE Integrated Field Research Challenge site, Oak Ridge, TN). Ethanol was injected intermittently as an electron donor to stimulate microbial U(VI) reduction, and U(VI) concentrations fell to below the Environmental Protection Agency drinking water standard (0.03 mg liter(-1)). Microbial communities from three monitoring wells were examined during active U(VI) reduction and maintenance phases with GeoChip, a high-density, comprehensive functional gene array. The overall microbial community structure exhibited a considerable shift over the remediation phases examined. GeoChip-based analysis revealed that Fe(III)-reducing bacterial (FeRB), nitrate-reducing bacterial (NRB), and sulfate-reducing bacterial (SRB) functional populations reached their highest levels during the active U(VI) reduction phase (days 137 to 370), in which denitrification and Fe(III) and sulfate reduction occurred sequentially. A gradual decrease in these functional populations occurred when reduction reactions stabilized, suggesting that these functional populations could play an important role in both active U(VI) reduction and maintenance of the stability of reduced U(IV). These results suggest that addition of electron donors stimulated the microbial community to create biogeochemical conditions favorable to U(VI) reduction and prevent the reduced U(IV) from reoxidation and that functional FeRB, SRB, and NRB populations within this system played key roles in this process. 相似文献
6.
Minipiezometers installed at different vertical levels within the streambed (20–140 cm) were used to study temporal and spatial variation in the dissolved organic carbon (DOC) content of streamwater and groundwater in three southern Ontario streams. Groundwater, as represented by our streambed samples, contained considerable quantities of DOC but variation between replicate samples was high. Diel fluctuations in DOC content of streamwater were consistent with daytime autochthonous production and night-time uptake by heterotrophs. Water from the streambed neither consistently diluted nor enhanced streamwater levels of DOC. At some stations, DOC variation with depth, including streamwater, seemed to be largely random. At other stations, DOC concentrations from the deepest piezometers were consistently higher than concentrations at intermediate depths, suggesting a loss of DOC from deeper waters to overlying sediments. However, at these stations DOC concentrations were highest at 20 cm and at the surface. Interflow delivery of DOC to the shallow layers of the streambed may be a significant source of carbon for a stream ecosystem, especially in agricultural areas. Late summer diel fluctuations at one station may be related to changing patterns of intermixing of stream and groundwater in the upper layers of the streambed as governed by velocity heads, convective currents and evapotranspiration. 相似文献
7.
Maria G E Albuquerque Gilda Carvalho Caroline Kragelund Ana F Silva Maria T Barreto Crespo Maria A M Reis Per H Nielsen 《The ISME journal》2013,7(1):1-12
The microbial community of a fermented molasses-fed sequencing batch reactor (SBR) operated under feast and famine conditions for production of polyhydroxyalkanoates (PHAs) was identified and quantified through a 16 S rRNA gene clone library and fluorescence in situ hybridization (FISH). The microbial enrichment was found to be composed of PHA-storing populations (84% of the microbial community), comprising members of the genera Azoarcus, Thauera and Paracoccus. The dominant PHA-storing populations ensured the high functional stability of the system (characterized by high PHA-storage efficiency, up to 60% PHA content). The fermented molasses contained primarily acetate, propionate, butyrate and valerate. The substrate preferences were determined by microautoradiography-FISH and differences in the substrate-uptake capabilities for the various probe-defined populations were found. The results showed that in the presence of multiple substrates, microbial populations specialized in different substrates were selected, thereby co-existing in the SBR by adapting to different niches. Azoarcus and Thauera, primarily consumed acetate and butyrate, respectively. Paracoccus consumed a broader range of substrates and had a higher cell-specific substrate uptake. The relative species composition and their substrate specialization were reflected in the substrate removal rates of different volatile fatty acids in the SBR reactor. 相似文献
8.
Dissolved organic carbon affects soil microbial activity and nitrogen dynamics in a Mexican tropical deciduous forest 总被引:1,自引:0,他引:1
Seasonal variation of dissolved organic C (DOC) and its effects on microbial activity and N dynamics were studied during two
consecutive years in soils with different organic C concentrations (hilltop and hillslope) in a tropical deciduous forest
of Mexico. We found that DOC concentrations were higher at the hilltop than at the hillslope soils, and in both soils generally
decreased from the dry to the rainy season during the two study years. Microbial biomass and potential C mineralization rates,
as well as dissolved organic N (DON) and NH4+ concentrations and net N immobilization were higher in soils with higher DOC than in soils with lower DOC. In contrast, net
N immobilization and NH4+ concentration were depleted in the soil with lowest DOC, whereas NO3− concentrations and net nitrification increased. Negative correlations between net nitrification and DOC concentration suggested
that NH4+ was transformed to NO3− by nitrifiers when the C availability was depleted. Taken together, our results suggest that available C appears to control
soil microbial activity and N dynamics, and that microbial N immobilization is facilitated by active heterotrophic microorganisms
stimulated by high C availability. Soil autotrophic nitrification is magnified by decreases in C availability for heterotrophic
microbial activity. This study provides an experimental data set that supports the conceptual model to show and highlight
that microbial dynamics and N transformations could be functionally coupled with DOC availability in the tropical deciduous
forest soils.
Responsible Editor: Chris Neill 相似文献
9.
The effects of mineral fertilizer and organic manure on soil microbial community and diversity 总被引:22,自引:0,他引:22
Wenhui Zhong Ting Gu Wei Wang Bin Zhang Xiangui Lin Qianru Huang Weishou Shen 《Plant and Soil》2010,326(1-2):523-523
The effects of mineral fertilizer (NPK) and organic manure on phospholipid fatty acid profiles and microbial functional diversity were investigated in a long-term (21-year) fertilizer experiment. The experiment included nine treatments: organic manure (OM), organic manure plus fertilizer NPK (OM + NPK), fertilizer NPK (NPK), fertilizer NP (NP), fertilizer NK (NK), fertilizer N (N), fertilizer P (P), fertilizer K (K), and the control (CK, without fertilization). The original soil was extremely eroded, characterized by low pH and deficiencies of nutrients, particularly N and P. The application of OM and OM + NPK greatly increased crop yields, soil pH, organic C, total N, P and K, available N, P and K content. Crop yields, soil pH, organic C, total N and available N were also clearly increased by the application of mineral NPK fertilizer. The amounts of total PLFAs, bacterial, Gram-negative and actinobacterial PLFAs were highest in the OM + NPK treatment, followed by the OM treatment, whilst least in the N treatment. The amounts of Gram-positive and anaerobic PLFAs were highest in the OM treatment whilst least in the P treatment and the control, respectively. The amounts of aerobic and fungal PLFAs were highest in the NPK treatment whilst least in the N and P treatment, respectively. The average well color development (AWCD) was significantly increased by the application of OM and OM + NPK, and the functional diversity indices including Shannon index (H ′ ), Simpson index (D) and McIntosh index (U) were also significantly increased by the application of OM and OM + NPK. Principal component analysis (PCA) of PLFA profiles and C source utilization patterns were used to describe changes in microbial biomass and metabolic fingerprints from nine fertilizer treatments. The PLFA profiles from OM, OM + NPK, NP and NPK were significantly different from that of CK, N, P, K and NK, and C source utilization patterns from OM and OM + NPK were clearly different from organic manure deficient treatments (CK, N, P, K, NP, NK 6 and NPK). Stepwise multiple regression analysis showed that total N, available P and soil pH significantly affected PLFA profiles and microbial functional diversity. Our results could provide a better understanding of the importance of organic manure plus balanced fertilization with N, P and K in promoting the soil microbial biomass, activity and diversity and thus enhancing crop growth and production. 相似文献
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利用DGGE法研究不同种植体系中根际微生物群落结构 总被引:7,自引:0,他引:7
利用DGGE技术研究不同间作和轮作种植体系对作物根际细菌和真菌群落结构的影响.运用16SrDNA和18SrDNA特异引物对,将土壤中提取的总DNA进行PCR扩增后,通过DGGE技术对PCR产物进行分析,结果表明:玉米-蚕豆轮作对蚕豆根际细菌和真菌群落结构影响明显,二者都与单作蚕豆有较大差异;小麦/蚕豆间作明显改变两种作物根际细菌群落结构和蚕豆根际真菌群落结构;玉米/蚕豆间作明显改变玉米根际细菌、真菌群落结构和蚕豆根际真菌群落结构. 相似文献
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Aims
The main objective was to describe the effects of plant litter on SOC and on soil microbial activity and structure in extensively managed grasslands in Central Germany that vary in biomass production and plant community composition.Methods
The decomposition of shoot and root litter was studied in an incubation experiment. Labile C and N were isolated by hot water extraction (CHWE, NHWE), while functional groups of microbes were identified by PLFA analysis and microbial activity was measured using a set of soil exo-enzymes.Results
The plant community composition, particulary legume species affected SOC dynamics and below-ground microbial processes, especially via roots. This was reflected in about 20% lower decomposition of root litter in low productivity grassland soil. The CHWE soil pool was found to be a key driver of the below-ground food web, controlling soil microbial processes.Conclusions
Below-ground responses appear to be related to the presence of legume species, which affected the microbial communities, as well as the ratio between fungal and bacterial biomass and patterns of soil enzyme activity. Low productivity fungal-dominated grasslands with slow C turnover rates may play an important role in SOC accumulation. The approach used here is of particular importance, since associated biological and biochemical processes are fundamental to ecosystem functioning. 相似文献13.
Dissolved organic carbon (DOC) fluctuations were studied in the surface water of Dal Lake from May 1984 to April 1985, at monthly intervals. Concentration of DOC varied from 0.140 mg l–1 to 0.725 mg l–1. A minimum was recorded in May and September, while an increase was observed during December and January. The fluctuations during the observation period showed a relationship with temperature and pH. 相似文献
14.
Rootstock genotype succession influences apple replant disease and root-zone microbial community composition in an orchard soil 总被引:2,自引:0,他引:2
Angelika St. Laurent Ian A. Merwin Gennaro Fazio Janice E. Thies Michael G. Brown 《Plant and Soil》2010,337(1-2):259-272
Apple replant disease (ARD) is a soil-borne disease complex that affects young apple trees in replanted orchards, resulting in stunted growth and reduced yields. Newly developed rootstock genotypes with tolerance to ARD may help to control this disease. We determined the effects of rootstock genotype rotations during orchard renovation, by investigating root-zone soil microbial consortia and the relative severity of ARD on seven rootstock genotypes (M.9, M.26, G.30, G.41, G.65, G.935, and CG.6210) planted in soil where trees on four of those same rootstocks (M.9, M.26, G.30 and CG.6210) had grown for the previous 15 years. Rootstock genotyping indicated that genetic distances among rootstocks were loosely correlated with their differential responses to ARD. Root-zone fungal and bacterial community composition, assessed by DNA fingerprinting (T-RFLP), differed between M.26 and CG.6210. Soil bacterial communities were influenced most by which rootstock had grown in the soil previously, while fungal communities were influenced more by the current replanted rootstock. In a clone library of bacteria from M.26 and CG.6210 root-zone soil, β-Proteobacteria was the most abundant phylum (25% of sequences). Sequences representing the Burkholderia cepacia complex were obtained only from CG.6210 soil. Rootstock genotypes that were grown in the orchard soil previously affected subsequent ARD severity, but replanting with the same or closely related rootstocks did not necessarily exacerbate this disease problem. Our results suggest that genotype-specific interactions with soil microbial consortia are linked with apple rootstock tolerance or susceptibility to ARD. 相似文献
15.
Controls on dissolved organic carbon composition and export from rice-dominated systems 总被引:3,自引:0,他引:3
Monika Krupa Robert G. M. Spencer Kenneth W. Tate Johan Six Chris van Kessel Bruce A. Linquist 《Biogeochemistry》2012,108(1-3):447-466
Rice field outflow can contain high concentrations of dissolved organic carbon (DOC), which plays a crucial role in drinking water quality and aquatic ecosystem processes. This study examined the relationship between potential determining factors (i.e. rice area, outflow, drainwater reuse, soil properties, and time, measured as the day in the growing season) and the concentration and composition of DOC exported from 11 rice-dominated subwatersheds. Samples were collected from subwatershed inflow and outflow every 1–2 weeks from May through September 2008 and analyzed for DOC concentration, trihalomethane formation potential (THMFP), and also specific ultraviolet absorbance (SUVA254) and the spectral slope parameter (S), which are indicators of DOC composition. Concentrations of DOC across all subwatersheds and sampling dates ranged from 1.56 to 14.43 mg L?1 (mean = 4.32 mg L?1). Linear mixed effects (LME) analysis indicated that DOC concentration decreased over time, and that THMFP, and DOC and THM flux, decreased over time, but increased with outflow. LME analysis of the SUVA254 and S parameters indicated that the fraction of aromatic DOC moieties increased with time, outflow, and reuse. Additionally, apparent peaks in DOC concentrations, THMFP, and SUVA254 coincided with the onsets of flooding and draining. Lastly, subwatersheds with outflow less than approximately 4,700 m3 ha?1 behaved as sinks of DOC. Our findings suggest that water management factors such as outflow, reuse, and discrete irrigation events, all of which vary over the course of the growing season, were the dominant determinants of DOC concentration and composition. 相似文献
16.
Bougon N Aquilina L Molénat J Marie D Delettre Y Chancerel E Vandenkoornhuyse P 《FEMS microbiology ecology》2012,80(1):98-113
We investigated the temporal and vertical changes in the microbial communities related to hydrological variations an aquifer (Brittany, France). Five water samplings were carried out, spanning three hydrological cycles in the variably and the permanently saturated zones. Seasonal variations in the major anion concentrations (NO3 -, SO4 2- and Cl(-) ) indicated that different physical processes occurred during the recharge process in the two zones. The variably saturated zone is mainly dominated by diffusion and advection processes from the soil, whereas the permanently saturated zone is controlled by moderate advective transfer from the variably saturated zone. Bacterial diversity was investigated by flow cytometry, 16S rRNA and narG genes analyses. Part of this diversity was new in that 6 of the 27 16S rRNA gene sequence phylotypes were unknown even at the class or phylum level. The narG gene analysis did not reveal any clear variation in time or depth within the nitrate reducers' community. In contrast, 16S rRNA gene analyses showed modifications of community composition that could be related to the hydrologic and chemical contrast between the two zones. It was concluded that the physical processes of water transfer could influence bacterial diversity at the soil-aquifer interface. 相似文献
17.
Dissolved organic carbon (DOC) and nitrogen (DON) concentrations were quantified in urban and rural watersheds located in central Texas, USA between 2007 and 2008. The proportion of urban land use ranged from 6 to 100% in our 12 study watersheds which included nine watersheds without waste water treatment plants (WWTP) and three watersheds sampled downstream of a WWTP. Annual mean DOC concentrations ranged 20.4–52.5 mg L?1. Annual mean DON concentrations ranged 0.6–1.9 mg L?1. Only the rural watersheds without a WWTP had significantly lower DOC concentrations compared to those watersheds with a WWTP but all the streams except two had significantly reduced DON compared to those with a WWTP. Analysis of the nine watersheds without a WWTP indicated that 68% of the variability in mean annual DOC concentration was explained by urban open areas such as golf courses, sports fields and neighborhood parks under turf grass. There was no relationship between annual mean DON concentration and any land use. Urban open area also explained a significant amount of the variance in stream sodium and stream sodium adsorption ratio (SAR). Ninety-four percent of the variance in annual mean DOC concentration was explained by SAR. Irrigation of urban turf grass with domestic tap water high in sodium (>181 mg Na+ L?1) may be inducing sodic soil conditions in watershed soils in this region resulting in elevated mean annual DOC concentrations in our streams. 相似文献
18.
Relationships between microbial community structure and hydrochemistry in a landfill leachate-polluted aquifer 总被引:21,自引:0,他引:21
Röling WF van Breukelen BM Braster M Lin B van Verseveld HW 《Applied and environmental microbiology》2001,67(10):4619-4629
Knowledge about the relationship between microbial community structure and hydrogeochemistry (e.g., pollution, redox and degradation processes) in landfill leachate-polluted aquifers is required to develop tools for predicting and monitoring natural attenuation. In this study analyses of pollutant and redox chemistry were conducted in parallel with culture-independent profiling of microbial communities present in a well-defined aquifer (Banisveld, The Netherlands). Degradation of organic contaminants occurred under iron-reducing conditions in the plume of pollution, while upstream of the landfill and above the plume denitrification was the dominant redox process. Beneath the plume iron reduction occurred. Numerical comparison of 16S ribosomal DNA (rDNA)-based denaturing gradient gel electrophoresis (DGGE) profiles of Bacteria and Archaea in 29 groundwater samples revealed a clear difference between the microbial community structures inside and outside the contaminant plume. A similar relationship was not evident in sediment samples. DGGE data were supported by sequencing cloned 16S rDNA. Upstream of the landfill members of the beta subclass of the class Proteobacteria (beta-proteobacteria) dominated. This group was not encountered beneath the landfill, where gram-positive bacteria dominated. Further downstream the contribution of gram-positive bacteria to the clone library decreased, while the contribution of delta-proteobacteria strongly increased and beta-proteobacteria reappeared. The beta-proteobacteria (Acidovorax, Rhodoferax) differed considerably from those found upstream (Gallionella, Azoarcus). Direct comparisons of cloned 16S rDNA with bands in DGGE profiles revealed that the data from each analysis were comparable. A relationship was observed between the dominant redox processes and the bacteria identified. In the iron-reducing plume members of the family Geobacteraceae made a strong contribution to the microbial communities. Because the only known aromatic hydrocarbon-degrading, iron-reducing bacteria are Geobacter spp., their occurrence in landfill leachate-contaminated aquifers deserves more detailed consideration. 相似文献
19.
Rousk J Brookes PC Glanville HC Jones DL 《Applied and environmental microbiology》2011,77(8):2791-2795
We studied how soil pH (pHs 4 to 8) influenced the mineralization of low-molecular-weight (LMW)-dissolved organic carbon (DOC) compounds, and how this compared with differences in microbial community structure. The mineralization of LMW-DOC compounds was not systematically connected to differences in soil pH, consistent with soil respiration. In contrast, the microbial community compositions differed dramatically. This suggests that microbial community composition data will be of limited use in improving the predictive power of soil C models. 相似文献
20.
Methyl ethyl ketone (MEK) is a common groundwater contaminant often present with more toxic compounds of primary interest. Because of this, few studies have been performed to determine the effect of microbial community structure on MEK biodegradation rates in aquifer sediments. Here, microcosms were prepared with aquifer sediments containing MEK following a massive spill event and compared to laboratory-spiked sediments, with MEK biodegradation rates quantified under mixed aerobic/anaerobic conditions. Biodegradation was achieved in MEK-contaminated site sediment microcosms at about half of the solubility (356 mg/L) with largely Firmicutes population under iron-reducing conditions. MEK was biodegraded at a higher rate [4.0 ± 0.74 mg/(L days)] in previously exposed site samples compared to previously uncontaminated sediments [0.51 ± 0.14 mg/(L days)]. Amplicon sequencing and denaturing gradient gel electrophoresis of 16S rRNA genes were combined to understand the relationship between contamination levels, biodegradation, and community structure across the plume. More heavily contaminated sediments collected from an MEK-contaminated field site had the most similar communities than less contaminated sediments from the same site despite differences in sediment texture. The more diverse microbial community observed in the laboratory-spiked sediments reduced MEK concentration 47 % over 92 days. Results of this study suggest lower rates of MEK biodegradation in iron-reducing aquifer sediments than previously reported for methanogenic conditions and biodegradation rates comparable to previously reported nitrate- and sulfate-reducing conditions. 相似文献