Influence Of Microbial Activity Research Articles

Influence of Microbial Activities on Fluorescent Dissolved Organic Matter in the Dark Canada Basin Waters

AbstractThe fluorescence characteristics of dissolved organic matter (DOM) were measured to determine the distribution and drivers of DOM in the dark Canada Basin waters. We studied the relationship between fluorescent DOM (FDOM) and apparent oxygen utilization (AOU) in the whole water column as well as in the main water masses (Pacific Winter Water, Atlantic halocline (AH), Atlantic water—Fram Strait and Barents Sea branches, Deep Temperature Minimum, and Canada Basin deep water). The relative water mass fractions of different water masses were estimated using a five end‐members mixing model. The distribution of water mass fractions was found to be in good agreement with the distribution based on the traditional temperature‐salinity diagram. The fractions of AH waters were linked with AOU, highlighting the significant role played by mineralization in shaping AH humic‐like levels. The slope of the relationship between in situ FDOM—AOU was greater than those reported in the other oceans worldwide. This suggests that the AH is a hot spot for microbial mineralization of humic‐like DOM. On the other hand, the relationships with the humic‐like intensities differed among the four humic‐like components in the >125 m waters, indicating distinct environmental dynamics and biogeochemical roles for each humic‐like component.

The Influence of Microbial Activities on the Capillary Pressure during H2 Injection: Implications for Underground H2 Storage

The Influence of Microbial Activities on the Capillary Pressure during H₂ Injection: Implications for Underground H₂ Storage

Influence of Microbial Activity on the Long-Term Alteration of Compacted Bentonite/Metal Chip Blocks

Influence of Microbial Activity on the Long-Term Alteration of Compacted Bentonite/Metal Chip Blocks

Biogeochemical transformation processes of iron, manganese, ammonium under coexisting conditions in groundwater based on experimental data

A dynamic column experiment using aquifer medium collected from a riverbank filtration (RBF) site in Northeast China was conducted to investigate the biogeochemical transformation processes of iron (Fe2+), manganese (Mn2+), ammonium (NH4+) and their interaction under coexisting conditions in real groundwater. Water parameters such as contaminant concentrations, pH and dissolved oxygen (DO) were determined while microbial analysis for the aquifer medium was performed through 16S rRNA sequencing. The results revealed that biochemical oxidation, reductive dissolution, adsorption were among the critical biogeochemical processes involved in the transformation of Fe2+, Mn2+ and NH4+, in which biological processes were the core process. The transformation rate of Fe2+, Mn2+ and NH4+ jointly revealed that the competition for DO existed throughout their co-oxidation process, and determined the spatial characteristics of their transformation processes to a certain extent. Fe2+ oxidation and nitrification primarily occurred in the upper oxidation zone (100 cm–70 cm), Mn2+ transformation and anaerobic ammonium oxidation (ANAMMOX) occurred mainly beneath the oxidation zone. The predominant area of microbial growth and metabolism was another key factor related to the spatial characteristics of biotransformation. The microbial analysis illustrated that Pseudomonas, Arthrobacter, Gallionella, Acinetobacter, Bacillus were among the dominant genera related to iron-oxidizing bacteria (IOB) and manganese-oxidizing bacteria (MnOB). The IOB-related genera were distributed mainly at 80 cm–60 cm with a relative abundance of 49%, MnOB-related genera were the most abundant (35%) bacteria at 60 cm–40 cm, and nitrifying bacteria (Nitrospira and Nitrosomonas) mainly existed in the upper part of the 100 cm–70 cm where nitrification occurred. The influence of microbial activity by changing chemical environment was manifested through the variation of transformation intensity during the experiment. The iron and manganese oxides generated by the bio-oxidation of Fe2+ and Mn2+ contributed significantly to the transformation of all three contaminants. The results may be valuable for understanding the evolution mechanism of groundwater when contaminated simultaneously with Fe2+, Mn2+ and NH4+.

Influence of Microbial Activity on Plant Growth Obtained from Vermicomposting Soil

Influence of Microbial Activity on Plant Growth Obtained from Vermicomposting Soil

Characteristics of microbial activity in atmospheric aerosols and its relationship to chemical composition of PM2.5 in Xi'an, China

Microbial activity levels in atmospheric aerosols can affect human health, and ecosystem and atmospheric processes. However, information on the influence of microbial activity in atmospheric aerosols remains very limited. In this study, the characteristics of microbial activity in atmospheric aerosols in Xi'an, China, were determined using the fluorescein diacetate hydrolysis method. The influences of meteorological factors, height and water-soluble inorganic ions on microbial activity were examined. The results indicate that the levels of the atmospheric inorganic ions increased as the air quality index (AQI) increased. The microbial activity and concentration of PM2.5 were significantly positively correlated during sampling period (p < 0.05). Notably, microbial activity levels in PM2.5 and PM10 both increased with the AQI and decreased from ground level to 228 m. Additionally, higher microbial activity levels were detected during floating dust events and lower levels were found during periods of rainfall. Among the nine inorganic ions, microbial activity was significantly positively correlated with Na+, Mg2+ and Ca2+ (p < 0.05). Correlation results indicate that microbial activity was greatly influenced by soil source in spring and summer. The present results improve our understanding of the correlations between airborne microbes and atmospheric chemical composition.

Calcium carbonate precipitation mediated by bacterial carbonic anhydrase in a karst cave: Crystal morphology and stable isotopic fractionation

Stable oxygen (δ18O) and carbon (δ13C) isotopes of speleothems are widely used as important proxies for paleoclimatic and paleoenvironment reconstructions. However, the influence of microbial activity on carbon and oxygen isotope fractionation during speleothem precipitation remains unclear. Bacterial carbonic anhydrase (CA) can promote calcium carbonate precipitation to catalyze the mutual transformation between CO2 and HCO3-. CA-producing bacteria (Lysinibacillus sp. strain LHXY2) were separated in the Xueyu Cave, Chongqing, SW China, and used in laboratory and cave in situ models to investigate their influence on the precipitation amount, mineral components, crystal morphology and carbon and oxygen isotope fractionation of CaCO3. A CA activity gradient was applied in the laboratory model by considering various CA inhibitor acetazolamide (AZ) concentrations, which showed that the CA activity could substantially enhance precipitation, alter the mineral components and morphology, and reduce the δ13C and δ18O values of the CaCO3 formed. Most importantly, the laboratory and in situ model results revealed approximately -7‰ and -1.4‰ δ13C shifts, respectively, compared to the bacteria-free model results, which indicated that microbial-driven carbon isotopic fractionation can cause great uncertainties in paleoclimate and paleoenvironment reconstructions.

Biological and physical modification of carbonate system parameters along the salinity gradient in shallow hypersaline solar salterns in Trapani, Italy

We investigated changes in the chemical characteristics of evaporating seawater under the influence of microbial activity by conducting geochemical analyses of the brines and evaporite sediments collected from solar salterns in Trapani, Italy. The microbial activity had a substantial effect on the carbonate system parameters. Dissolved inorganic carbon (DIC) was substantially removed from the brine during the course of evaporation from the seawater to the point where calcium carbonate precipitates, with an accompanying decrease in its carbon isotopic composition (δ13CDIC) to as low as −10.6‰. Although the removal of DIC was due to calcium carbonate precipitation, photosynthesis, and the degassing of CO2(aq) induced by evaporation, the presence of 13C-depleted δ13CDIC in ponds where calcium carbonate precipitates can be attributed to the dissolution of atmospheric CO2 because of intensive CO2(aq) uptake by photosynthesis, and/or mineralization of organic matter by sulfate reduction. In contrast, δ13CDIC increased up to 7.2‰ in the salinity range where halite precipitates, which can be ascribed to the domination of the effect of degassing of CO2(aq) under conditions with reduced microbial activity. A gradual decrease in microbial activity was also reflected in compound-specific δ13C of photosynthetic pigments; isotopic fractionation associated with DIC assimilation increased linearly as the evaporation proceeded, indicating DIC-limited conditions within the microbial mats and gypsum crusts because of restricted DIC diffusion from the overlying brine and/or suppression of primary production at higher salinity.

Influence of microbial activity on the physical properties and strength of ilmenite and magnetite ores

The influence of microorganisms on the physical properties and strength of ilmenite and magnetite ores was determined in culture studies and laboratory tests of rock parameters such as absorption, porosity, elastic wave velocity, and uniaxial compressive strength. Initial pH condition was determined in the culture experiments, and then abiotic and biotic oxidation tests were performed to determine variations in pH, physical properties, and the strengths of the two ferruginous ore rocks. For ilmenite and magnetite ores, average initial values were, respectively, 0.185% and 0.496% for porosity, 0.046% and 0.123% for absorption, 1919 m/s and 1467 m/s for elastic wave velocity, and 432 MPa and 168 MPa for uniaxial compressive strength. The pH of ilmenite ore at the end of the abiotic and biotic oxidation tests was in the range of 3.82–4.26 and 2.20–2.57, respectively, while that of magnetite ore was 4.02–5.16 and 1.50–1.90, respectively. In magnetite ore, the changes in porosity and absorption due to the biotic oxidation test were larger than those observed in the abiotic oxidation test, while the variations in ilmenite ore due to both tests (abiotic and biotic oxidation) were small. The differences in porosity and absorption between the abiotic and biotic oxidation tests were larger in magnetite ore than in ilmenite ore, while the elastic wave velocity was smaller in magnetite ore than in ilmenite ore. In addition, the variations in uniaxial compressive strength due to the abiotic oxidation test were not significantly different than initial values in both ilmenite and magnetite ores, while variations caused by the biotic oxidation test were relatively large in both ferruginous ore rocks. Our results suggest that variations in the physical properties and strength of ilmenite and magnetite ores are largely dependent on microbial activity.

Glauconitic laminated crusts from hydrothermal alteration of Jurassic pillow-lavas (Betic Cordillera, S Spain): a microbial influence case

The green crusts infilling the spaces among pillow-lava bodies from the Median Subbetic (Betic Cordillera, S Spain) are the subject of this textural, mineralogical and geochemical study. The exceptional laminated morphology and mineral composition made it possible to establish the genetic conditions and different phases of the infilling, while also interpreting the possible influence of microbial activity in the origin and growth of the laminated crusts. Two types of crusts were discerned: green laminated crusts and black crusts. The green crusts are mostly composed by glauconite and celadonite, and a minority by smectites, whereas black crust and lens-shaped nappes are saponitic. The record of filaments and coccoid-shaped forms at different scales from the glauconitic crusts indicates the potential implication of chemoorganotrophic microbes in the precipitation of the glauconite and the development of laminated textures under low-temperature hydrothermal conditions. In an early stage, alteration of pillow-lava surfaces with influence of hydrothermal reducing fluids results in black films of saponite and calcite filling the void spaces. During a cooling phase, green laminated crusts composed by glauconite and celadonite grow under oxic conditions due to the circulation and diffusion of oxygenated sea-water along inter-pillow spaces and the chemoorganotrophic microbial activity. A new stage of saponite formation with calcite occurs under higher T and confined-reducing conditions resulting from deposition of marine sediments, and finally calcite and quartz crystallise as the latest product closing the remaining space (or producing geodes) among the pillow-lava bodies.

Relationships between major ions in coal seam gas groundwaters: Examples from the Surat and Clarence-Moreton basins

Using a combination of multivariate statistical techniques and the graphical assessment of major ion ratios, the influences on hydrochemical variability of coal seam gas (or coal bed methane) groundwaters from several sites in the Surat and Clarence-Moreton basins in Queensland, Australia, were investigated. Several characteristic relationships between major ions were observed: 1) strong positive linear correlation between the Na/Cl and alkalinity/Cl ratios; 2) an exponentially decaying trend between the Na/Cl and Na/alkalinity ratios; 3) inverse linear relationships between increasing chloride concentrations and decreasing pH for high salinity groundwaters; and 4) high residual alkalinity for lower salinity waters, and an inverse relationship between decreasing residual alkalinity and increasing chloride concentrations for more saline waters. The interpretation of the hydrochemical data provides invaluable insights into the hydrochemical evolution of coal seam gas (CSG) groundwaters that considers both the source of major ions in coals and the influence of microbial activity. Elevated chloride and sodium concentrations in more saline groundwaters appear to be influenced by organic-bound chlorine held in the coal matrix; a sodium and chloride ion source that has largely been neglected in previous CSG groundwater studies. However, contrastingly high concentrations of bicarbonate in low salinity waters could not be explained, and are possibly associated with a number of different factors such as coal degradation, methanogenic processes, the evolution of high-bicarbonate NaHCO3 water types earlier on in the evolutionary pathway, and variability in gas reservoir characteristics. Using recently published data for CSG groundwaters in different basins, the characteristic major ion relationships identified for new data presented in this study were also observed in other CSG groundwaters from Australia, as well as for those in the Illinois Basin in the USA. This observation suggests that where coal maceral content and the dominant methanogenic pathway are similar, and where organic-bound chlorine is relatively abundant, distinct hydrochemical responses may be observed. Comparisons with published data of other NaHCO3 water types in non-CSG environments suggest that these characteristic major ion relationships described here can: i) serve as an indicator of potential CSG groundwaters in certain coal-bearing aquifers that contain methane; and ii) help in the development of strategic sampling programmes for CSG exploration and to monitor potential impacts of CSG activities on groundwater resources.

Provenance and fate of arsenic and other solutes in the Chaco-Pampean Plain of the Andean foreland, Argentina: From perspectives of hydrogeochemical modeling and regional tectonic setting

Extensive arsenic (As) enriched groundwater is known to occur in the aquifers of the Chaco-Pampean Plain of Argentina. Previous studies speculated that the As mobilization in these groundwaters was a direct result of their elevated pH and oxidative conditions. The volcanic glass layers present in the aquifer matrix were hypothesized as one of the possible sources of As to the groundwaters. Here, we examine the groundwater chemistry of the Santiago del Estero province of Chaco-Pampean Plains of Argentina, and test these hypotheses by using hydrogeochemical modeling within the framework of the regional geologic–tectonic setting. The study area is located in the active foreland of the Andean orogenic belt, which forms a continental arc setting, and is dotted with several hot springs. Rhyolitic volcanic glass fragments derived from arc volcanism are abundant within the aeolian–fluvial aquifer sediments, and are related to the paleo-igneous extrusion in the vicinity. Hydrogeochemical analyses show that the groundwater is in predominantly oxidative condition. In addition, some of the groundwaters exhibit very high Na, Cl− and SO42- concentrations. It is hypothesized in this study that the groundwater chemistry has largely evolved by dissolution of rhyolitic volcanic glass fragments contained within the aquifer sediments along with mixing with saline surface waters from, adjoining salinas, which are thought to be partially evaporated remnants of a paleo inland sea. Flow path modeling, stability diagrams, and thermodynamic analyses undertaken in this study indicate that the dominant evolutionary processes include ion exchange reactions, chemical weathering of silicate and evaporites, in monosialitization-dominated weathering. Geochemical modeling predicts that plagioclase feldspar and volcanic glass are the major solids phases that contribute metal cations and dissolved silica to the local groundwaters. Co-influxed oxyanions, with similar ionic radii and structure (e.g. Mo, Si, V, PO43-), compete with As for mineral surface site, leading to As mobilization to the groundwaters (without considering the influence of microbial activities). Further, the transition of the Ca-rich groundwater to Na-rich groundwater, by mixing with water from the salinas and/or evaporative concentration, might also have led to counter-ion effects (a type of ion exchange reactions), and hence, further enrichment of groundwater by As. Some of the As may also have been contributed from mixing of meteoric water with magmatic-sourced water in the geothermal springs.

Evolution of silica accumulation in the earth’s history and its relation to biota development

Two branches of silica rockevolution related to oceans and continental blocks have been outlined. The boundaries of changes in types of silica rocks, their formation, and development of the organic world were established: (i) the beginning of the Phanerozoic was related to transformation from microbial to biogenic silica deposition (or to a change in the influence of microbial activity on silica accumulation); (ii) cessation of the formation of cherts enriched in organic matter, which was synchronized with land colonization by organisms in the Devonian, and (iii) an explosive style of global silica accumulation related to the appearance and development of diatoms, which correlates with appearance of angiosperm plants in tropical forests.

Mound springs in the arid Lake Eyre South region of South Australia: A new depositional tufa model and its controls

The mound springs of the Lake Eyre South region of South Australia are rare but prominent, dome-shaped accumulations of largely calcium carbonate deposited by artesian springs. Despite similar formations being found worldwide, few intensive studies of the formation and ongoing evolution of these structures exist. In this study, samples from a selection of active mound springs were subjected to petrological and Scanning Electron Microscopy (SEM) techniques to gain insight into mound spring morphology. Additionally, microcosms containing three types of artificial substrate (marble, glass and copper) were placed within active mound spring environments to aid determination of the rate, spatial extent and the influence of microbial activity on carbonate precipitation. Finally, water samples from spring vents were analyzed for water quality and major ions. Carbonate deposits were interpreted to be largely plant or microbial tufa. From the microcosms, thrombolitic-textured micrite was deposited on only the marble and glass substrates and only within spring tails distal from vents. Precipitation rates from the microcosm experiment of between 0.15 and 1.6 kg m −2 yr −1 are similar to rates observed at cyanobacteria-associated, low-energy, carbonate depositing environments. These results suggest that tufa precipitation is linked to the development of extracellular polymeric substances. Conversely, it was interpreted that emergent spring water is calcite under-saturated based on water chemistry analyses and marble dissolution proximal to spring vents. A number of factors important to the formation of mound springs were determined; including the role of bio-mineralization and hydrophytes in mound construction and the implications for time-limited and spatially dynamic precipitation on spring flow.

The influence of microbial activity on rock fluid interaction: Baseline characterization of deep biosphere for Enhanced Gas Recovery in the Altmark natural gas reservoir

In this study the first results of the microbial monitoring within the framework of the CLEAN project are described. The microbial community of a 3.5 km deep depleted gas reservoir in Altmark, Germany was analyzed by molecular genetic techniques. Sequence analyses indicated the presence of microorganisms similar to previously identified microbes from saline, thermophilic and anaerobic environments in the deep hypersaline and hot reservoir environments. The results of the phylogenetic analyses revealed the presence of the different H2-oxidising bacteria (Hydrogenophaga sp., Acidovorax sp., Ralstonia sp., Pseudomonas sp.), thiosulfate-oxidising bacteria (Diaphorobacter sp.) and biocorrosive thermophilic microorganisms.

Microbial activity and water-soluble trace element species in the rhizosphere of spring wheat (Triticum aestivum cv. USU-Perigee)

The influence of microbial activity on the concentration and speciation of trace elements (TEs) was assessed in a study on the bioavailability of TEs for edible plants. A growth chamber experiment with spring wheat (Triticum aestivum cv. USU-Perigee) was conducted and the bulk (Bk) and the rhizosphere (Rz) soil components were collected at maturity. A characterization of the microbial activity and population was made by measuring the microbial biomass, enzymes (acid phosphatase, arylsulfatase, dehydrogenase and urease) and 16S rDNA DGGE profiles. In soil water extracts, major solutes (H(+), Ca, Mg, Na, NH(4), K, Cl, NO(3), SO(4), total N, DON and DOC) and trace elements (Al, As, Cd, Ce, Cr, Cu, Fe, Pb, Tl, and Zn) including monomeric Al species, free Cu(2+) and labile Zn were determined. The partition of the variation indicated that 12.1% of the distribution of TEs in the Bk soil was significantly and exclusively explained by chemical properties while this value was less than 0.1% for the Rz soil. To the contrary, microbial properties contributed significantly to 12.3% of the distribution of TEs in the Rz soil whereas it explained less than 0.1% for the Bk soil. Detailed redundancy analyses identified several potential mechanisms (e.g. weathering of primary mineral, solubilisation of sesquioxides, bacterial effect on the redox status) explaining the fate of TEs in the Bk and Rz soils. This study revealed that microbial activity is strongly associated to the speciation of trace elements in the Rz of edible plants and points to some microbial processes influencing TE speciation.

Influence of microbial activity on polar xenobiotic degradation in activated sludge systems

Publisher‘s note. We very much regret that in production certain errors were introduced into the above article. We wish to apologise to authors and readers for these errors and any confusion that may have been caused: the corrections are given below.

Influence of microbial activity on polar xenobiotic degradation in activated sludge systems

The influence of activated sludge quality on the co-metabolic biodegradation of three aminocarboxylic [corrected] acids was investigated for a variety of Luxembourg sewage treatment plants. A combination of biodegradation experiments and respirometric techniques are presented as a reliable approach for the estimation of biokinetics and biological xenobiotic degradation rates that allow for identification of governing parameters such as microbial activity and active biomass. Results showed that biokinetics and degradation rates vary greatly between different plants. The fraction of active biomass on the total suspended solids ranged between 16.9 and 53.7%. Xenobiotic biodegradation rates correlated with microbial activity suggesting a relationship with WWTP performance for carbon and nutrient removal. The biokinetic information can be used to increase the prediction accuracy of xenobiotics removal by individual WWTPs.

Photosynthetic isotope biosignatures in laminated micro-stromatolitic and non-laminated nodules associated with modern, freshwater microbialites in Pavilion Lake, B.C.

The influence of microbial activity on carbonate precipitation was investigated within micro-stromatolitic nodules associated with modern, freshwater microbialites located in Pavilion Lake, B.C. Observed carbonate δ 13C values enriched by up to + 3.6‰ as compared to predicted abiotic carbonate δ 13C values from measured dissolved inorganic carbon (mean − 1.2‰, n = 13) were consistent with microbial photosynthetic influence on in situ precipitation within the nodule microenvironment. Estimated carbonate precipitation temperatures within the nodules based on δ 18O were consistent with recorded summertime temperatures, indicative of precipitation during the period of highest levels of photosynthetic activity. Low δ 13C values of organic matter within the nodules (− 30.6 to − 21.1‰) and an average inorganic to organic carbon Δ δ 13C value of 26.8‰ reflected the preferential uptake of 12C during non-CO 2 limited photosynthesis, supporting the generation of 13C-enriched DIC. Microelectrode profiles through the nodules showed oxygen supersaturation of up to ∼ 275%, elevated pH compared to ambient water and a lack of any observable dissolved sulphide, Mn or Fe further indicated that photosynthetic activity was the predominant metabolic process within the nodule during light exposure. Microbial phospholipid fatty acid profiles of the nodule communities were indicative of bacteria rather than eukaryotes and PLFA δ 13C values were depleted relative to the bulk cell by 2.6–6.6‰, consistent with a predominance of photosynthetic microbes. Scanning electron microscopy images of the relationship between carbonate minerals and filaments indicated that carbonate precipitation had occurred in situ due to microbial influences on the geochemistry within the nodule microenvironment rather than due to cell surface effects or trapping and binding. The observation of photosynthetically induced 13C-enrichment of in situ precipitated carbonate within the nodule microenvironment is thus a biosignature of the activity of these surface communities and is consistent with the hypothesized role of biology in the formation of microbialites.

Fermentation of cocoa beans: influence of microbial activities and polyphenol concentrations on the flavour of chocolate

AbstractBACKGROUND: Spontaneous cocoa bean fermentation is characterised by a succession of microbial activities. Cocoa flavour precursors are developed during fermentation and drying of cocoa beans. Polyphenols and alkaloids contribute to astringency and bitterness of cocoa and chocolate.RESULTS: Population dynamics, metabolite target analyses, and chocolate production were performed for seven independent spontaneous cocoa bean heap fermentations in Ghana. Although the same micro‐organisms were involved in these heaps, carried out at different farms or in different seasons, heap temperatures and microbial metabolite concentrations were different. This could be due to heterogeneity and size of the heaps, but was mainly ascribed to microbial variability. Indeed, differences in microbial activity could be linked with the flavour of chocolates made from the corresponding dried, fermented cocoa beans. Whereas the polyphenol and alkaloid contents of cocoa beans were crop‐ and heap‐dependent, epicatechin and theobromine levels decreased during fermentation due to diffusion out of the bean cotyledons and polyphenol oxidation and condensation. Residual levels were responsible for the degree of bitterness of the final chocolates.CONCLUSION: Differences in microbial activities between different heap fermentations can result in dried fermented cocoa beans and chocolates with different flavour characteristics. Hence, fermentation control may direct the flavour of chocolate. Copyright © 2008 Society of Chemical Industry