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1

Soil Biology & Biochemistry 38 (2006) 24482460 Response of soil microbial biomass and enzyme activities to the  

E-print Network

Soil Biology & Biochemistry 38 (2006) 2448­2460 Response of soil microbial biomass and enzyme as controls to monitor the chamber effect. Elevated CO2 induced mainly an increase of enzyme activities the pool of easily available substrates mainly in the upper soil layers, enzyme regulation (production

Minnesota, University of

2

Humic substances biological activity at the plant-soil interface  

PubMed Central

Humic substances (HS) represent the organic material mainly widespread in nature. HS have positive effects on plant physiology by improving soil structure and fertility and by influencing nutrient uptake and root architecture. The biochemical and molecular mechanisms underlying these events are only partially known. HS have been shown to contain auxin and an “auxin-like” activity of humic substances has been proposed, but support to this hypothesis is fragmentary. In this review article, we are giving an overview of available data concerning molecular structures and biological activities of humic substances, with special emphasis on their hormone-like activities. PMID:20495384

Trevisan, Sara; Francioso, Ornella; Nardi, Serenella

2010-01-01

3

Soil Biology & Biochemistry 39 (2007) 10141022 Influence of earthworm activity on aggregate-associated carbon and  

E-print Network

Soil Biology & Biochemistry 39 (2007) 1014­1022 Influence of earthworm activity on aggregate of California, Davis, CA 95616, USA b Institute of Ecology and Department of Crop and Soil Sciences, University regulators of soil structure and soil organic matter (SOM) dynamics, however, quantifying their influence

van Kessel, Chris

4

Effect of Treated Wastewater Irrigation on Plant Growth and Biological Activity in Three Soil Types  

Microsoft Academic Search

The effects of two types of treated wastewater on soil biological activity were studied in a pot experiment. Four irrigation treatments were tested on both soils sown with barley and unsown soils: distilled water (DW), half-strength Hoagland nutrient solution (NS), treated wastewater from a conventional treatment plant (CWW), and treated wastewater from a lagoon (LWW). Three types of soils were

Maria Adrover; Gabriel Moyŕ; Jaume Vadell

2012-01-01

5

Detection and Investigation of Soil Biological Activity against Meloidogyne incognita  

PubMed Central

Greenhouse experiments with two susceptible hosts of Meloidogyne incognita, a dwarf tomato and wheat, led to the identification of a soil in which the root-knot nematode population was reduced 5- to 16-fold compared to identical but pasteurized soil two months after infestation with 280 M. incognita J2/100 cm3 soil. This suppressive soil was subjected to various temperature, fumigation and dilution treatments, planted with tomato, and infested with 1,000 eggs of M. incognita/100 cm3 soil. Eight weeks after nematode infestation, distinct differences in nematode population densities were observed among the soil treatments, suggesting the suppressiveness had a biological nature. A fungal rRNA gene analysis (OFRG) performed on M. incognita egg masses collected at the end of the greenhouse experiments identified 11 fungal phylotypes, several of which exhibited associations with one or more of the nematode population density measurements (egg masses, eggs or J2). The phylotype containing rRNA genes with high sequence identity to Pochonia chlamydosporia exhibited the strongest negative associations. The negative correlation between the densities of the P. chlamydosporia genes and the nematodes was corroborated by an analysis using a P. chlamydosporia-selective qPCR assay. PMID:19259527

Bent, E.; Loffredo, A.; McKenry, M. V.; Becker, J. O.; Borneman, J.

2008-01-01

6

Effects of Moisture, Temperature, and Biological Activity on the Degradation of Isoxaflutole in Soil  

E-print Network

Effects of Moisture, Temperature, and Biological Activity on the Degradation of Isoxaflutole on the dissipation, transformation, and mineralization of isoxaflutole were investigated in laboratory incubations, which were found only in small quantities. Degradation of isoxaflutole was faster in soil maintained

Sims, Gerald K.

7

SOIL BIOLOGY AND ECOLOGY  

EPA Science Inventory

The term "Soil Biology", the study of organism groups living in soil, (plants, lichens, algae, moss, bacteria, fungi, protozoa, nematodes, and arthropods), predates "Soil Ecology", the study of interactions between soil organisms as mediated by the soil physical environment. oil ...

8

Secondary successional patterns in a sagebrush (Artemisia tridentata) community as they relate to soil disturbance and soil biological activity  

Microsoft Academic Search

The relationship between secondary succession, soil disturbance, and soil biological activity were studied on a sagebrush community (Artemisia tridentata) in the Piceance Basin of northwestern Colorado, U.S.A. Four levels of disturbance were imposed. I: the vegetation was mechanically removed and as much topsoil as possible was left; 2: the vegetation was mechanically removed and the topsoil scarified to a depth

Mario E. Biondini; Charles D. Bonham; Edward F. Redente

1985-01-01

9

[Biological activity of soils in the settlements of southern (Microtus rossiaemeridionalis) and bank (Clethrionomys glareolus) voles].  

PubMed

The effect of southern (Microtus rossiaemeridionalis) and bank (Clethrionomys glareolus) voles on the biological activity of soddy-podzolic soil and culturozem has been studied. To estimate this effect, the activity of nitrogen and carbon transformation in the soil taken from the paths and different chambers of the holes of these rodents, as well as from the control plots where there were no voles, has been determined. The contents of organic carbon and nitrogen in the soil have been found. The parameters of functional diversity of the microbial community of soil have been studied. It has been noted that the effect of voles on the biological activity of the above soils manifested itself in increased intensity of aerobic and anaerobic destruction of organic matter and changes in the parameters of functional diversity of the microbial community of soils. PMID:24459855

Manaeva, E S; Kostina, N V; Gorlenko, M V; Lomovtseva, N O; Umarov, M M

2013-01-01

10

The effect of a bacterial-humus preparation on the biological activity of soils  

NASA Astrophysics Data System (ADS)

The influence of the Gumigel bacterial-humus preparation on the biological activity of soils was investigated. The activity was assessed by the respiration intensity of the soil microorganisms, the total number of bacteria, and the structure of the saprotrophic bacterial complex. It was demonstrated that the microorganisms were preserved in the preparation for a long time. As this preparation was kept at 4°C, the number of microorganisms was preserved at a permanent level during no less than half a year. The preparation did not have a significant effect on the biological activity of the unpolluted soil, but it intensified the biological activity in the case of the polluted soil, which was seen from an increase in the number of microorganisms and their respiration intensity.

Tsyganova, E. N.; Zvyagintsev, D. G.; Lysak, L. V.; Stepanov, A. L.

2013-07-01

11

Effects of gentle remediation technologies on soil biological and biochemical activities - a review.  

NASA Astrophysics Data System (ADS)

Remediation technologies for contaminated sites are generally designed to reduce risks for human health, groundwater or plant quality. While some drastic remediation measures such as soil excavation, thermal treatment or soil washing eliminate or strongly reduce soil life, in-situ treatments involving plants or immobilizing additives may also restore soil functionality by establishing or promoting a well structured and active community of soil organisms. Biological parameters that are sensitive to contaminants and other pedo-environmental conditions and which contribute to biogeochemical nutrient cycles, can be used as synthetic indicators of the progress and also the efficiency of given remediation approaches. Data from long-term studies on re-vegetated mine spoils show that biological and biochemical activity is enhanced with increasing plant density and diversity. Among the soil amendments, most measures that introduce organic matter or alkalinity to the contaminated soils also improve microbial or faunal parameters. Only few amendments, such as phosphates and chelators have deleterious effects on soil biota. In this review, soil microbial biomass and the activity of the enzymes phosphatase and arylsulphatase are identified as suitable and sensitive biological indicators for soil health. The results and future research needs are are summarized.

Marschner, B.; Haag, R.; Renella, G.

2009-04-01

12

Evaluating the biological activity of oil-polluted soils using a complex index  

NASA Astrophysics Data System (ADS)

A complex index characterizing the biological activity of soils (BAS) is suggested. It is based on an estimate of the level of activity of catalase; the number of heterotrophic and hydrocarbon oxidizing microorganisms, microscopic fungi, algae, and cyanobacteria; and the degree of development of higher plants and insects in the studied soil. The data on using the BAS coefficient for evaluating the efficiency of rehabilitation measures for oil-polluted soils are given. Such measures included introducing the following biological preparations: Lenoil based on a natural consortium of microorganisms Bacillus brevis and Arthrobacter sp.; the Azolen biofertilizer with complex action based on Azotobacter vinelandii; the Belvitamil biopreparation, which is the active silt of pulp and paper production; and a ready-mixed industrial association of aerobic and anaerobic microorganisms that contains hydrocarbon oxidizing microorganisms of the Arthrobacter, Bacillus, Candida, Desulfovibrio, and Pseudomonas genera.

Kabirov, R. R.; Kireeva, N. A.; Kabirov, T. R.; Dubovik, I. Ye.; Yakupova, A. B.; Safiullina, L. M.

2012-02-01

13

Soil organic matter dynamics under Beech and Hornbeam as affected by soil biological activity  

NASA Astrophysics Data System (ADS)

Organic matter dynamics are highly affected both the soil fauna as well as the source of organic matter, having important consequences for the spatial heterogeneity of organic matter storage and conversion. We studied oldgrowth mixed deciduous forests in Central-Luxemburg on decalcified dolomitic marl, dominated by high-degradable hornbeam (Carpinus betulus L.) or low-degradable beech (Fagus sylvatica L.). Decomposition was measured both in the laboratory and in the field. Litter decomposition was higher for hornbeam than for beech under laboratory conditions, but especially in the field, which is mainly to be attributed to macro-fauna activity, specifically to earthworms (Lumbricus terrestris and Allolobophora species). We also investigated differences between beech and hornbeam with regard to litter input and habitat conditions. Total litter input was the same, but contribution of beech and hornbeam litter clearly differed between the two species. Also, mass of the ectorganic horizon and soil C:N ratio were significantly higher for beech, which was reflected in clear differences in the development of ectorganic profiles on top of the soil. Under beech a mull-moder was clearly present with a well developed fermentation and litter horizon, whereas under hornbeam all litter is incorporated into the soil, leaving the mineral soil surface bear in late summer (mull-type of horizon). In addition to litter quality, litter decomposition was affected by pH and soil moisture. Both pH and soil moisture were higher under hornbeam than under beech, which may reflect differences in soil development and litter quality effects over longer time scales. Under beech, dense layers of low-degradable litter may prevent erosion, and increase clay eluviation and leaching of base cations, leading to acid and dry conditions, which further decrease litter decay. Under hornbeam, the soil is not protected by a litter layer, and clay eluviation and acidification may be counteracted by erosion, and earthworms bringing clay and base cations back to the surface. It may be concluded that beech and hornbeam stands show clear differences in both input and decomposition rates. They are also fixed to habitat conditions that can be clearly differentiated in the field allowing for a spatial analysis of organic matter dynamics and input.

Kooijman, A. M.; Cammeraat, L. H.

2009-04-01

14

Activation of Methanogenesis in Arid Biological Soil Crusts Despite the Presence of Oxygen  

PubMed Central

Methanogenesis is traditionally thought to occur only in highly reduced, anoxic environments. Wetland and rice field soils are well known sources for atmospheric methane, while aerated soils are considered sinks. Although methanogens have been detected in low numbers in some aerated, and even in desert soils, it remains unclear whether they are active under natural oxic conditions, such as in biological soil crusts (BSCs) of arid regions. To answer this question we carried out a factorial experiment using microcosms under simulated natural conditions. The BSC on top of an arid soil was incubated under moist conditions in all possible combinations of flooding and drainage, light and dark, air and nitrogen headspace. In the light, oxygen was produced by photosynthesis. Methane production was detected in all microcosms, but rates were much lower when oxygen was present. In addition, the ?13C of the methane differed between the oxic/oxygenic and anoxic microcosms. While under anoxic conditions methane was mainly produced from acetate, it was almost entirely produced from H2/CO2 under oxic/oxygenic conditions. Only two genera of methanogens were identified in the BSC-Methanosarcina and Methanocella; their abundance and activity in transcribing the mcrA gene (coding for methyl-CoM reductase) was higher under anoxic than oxic/oxygenic conditions, respectively. Both methanogens also actively transcribed the oxygen detoxifying gene catalase. Since methanotrophs were not detectable in the BSC, all the methane produced was released into the atmosphere. Our findings point to a formerly unknown participation of desert soils in the global methane cycle. PMID:21655270

Angel, Roey; Matthies, Diethart; Conrad, Ralf

2011-01-01

15

Biosurfactants for Soil Biology  

Microsoft Academic Search

\\u000a Biosurfactants are microbially produced surface active agents with applications in soil bioremediation particularly in removing\\u000a hydrocarbon and heavy metal contaminants from soil. Use of biosurfactants enhances the solubilisation, removal, bioavailability\\u000a and biodegradation of hydrocarbons in soil. Biosurfactants solubilise hydrocarbons into the aqueous phase of soil where they\\u000a can be either removed by soil washing or biodegraded by microbes. Various aliphatic,

Poonam Mudgil

16

EFFECT OF NITROGEN AND METAL ADDITIONS ON NITROGEN FIXATION ACTIVITY IN BIOLOGICAL SOIL CRUSTS  

NASA Astrophysics Data System (ADS)

Biological soil crusts (BSCs) are diverse consortia of microorganisms that live in intimate association with soils in arid environments. Also called cryptogamic or microbiotic crusts, these communities can include cyanobacteria, algae, heterotrophic bacteria, fungi, lichens, and mosses. Together, these organisms provide many services to their surrounding ecosystems, including reduction of water runoff, promotion of water infiltration, and prevention of soil erosion. The cyanobacteria and algae also provide fixed carbon (C) to the soil through photosynthesis, and because atmospheric deposition of nitrogen (N) in arid environments is low, the major input of biologically available N comes from cyanobacteria capable of converting nitrogen gas (N2) to ammonium (NH4+). Biological soil crusts are easily destroyed by livestock grazing, motor vehicle travel, and many forms of recreational and agricultural land use. Loss of BSC cover can leave the soil vulnerable to intense erosion that can remove the nutrients necessary to sustain plant and animal life, thus accelerating the process of desertification. In order to preserve existing crusts and encourage the development of new crusts, it is crucial to understand the nutrient requirements of metabolism and growth in these microbial communities. This study investigated the affect of nitrogen and metal additions on N2-fixation activity in cyanobacterially-dominated crusts from the Colorado Plateau near Moab, Utah. Although N2-fixation has been studied in this system before, the affect of nutrient additions on N2-fixation activity has not been documented. The goal of this work was to understand how N and metal supplementation affects crust N metabolism. Three experiments were conducted to observe how N2-fixation activity changed with the addition of N, molybdenum (Mo), and vanadium (V). Molybdenum and vanadium were chosen because they are most commonly found at the active site of the enzyme nitrogenase, the molecule responsible for the biological conversion of N2 to NH4+. The Mo-dependent version of the enzyme is the most efficient, and it is used by the majority of N2-fixing organisms. Elements were added as aqueous solutions of NH4NO3, Na2MoO4, and Na3VO4 respectively. Nitrogen fixation potential was assayed using a modified acetylene reduction technique. Results from the N-addition experiment show that when N is provided, BSC organisms stop N2-fixation activity. This confirms that under natural conditions, the community is limited with respect to N. In general, crusts under Mo-addition fix at higher rates than crusts with no added Mo. This implies that crusts may also be limited with respect to Mo. However, contrary to our expectations, crusts fix at lower rates when V is added as compared to a no-V control. It is possible that this is the result of V-toxicity, or that V competes with the uptake and utilization of available Mo, thus exacerbating Mo-limitation. Experiments are currently underway to investigate how the geochemistry of the soil porewater changes as a result of these nutrient additions.

Alexander, K.; Lui, D.; Anbar, A. D.; Garcia-Pichel, F.; Hartnett, H. E.

2009-12-01

17

The impact of land use on biological activity of agriculture soils. An State-of-the-Art  

NASA Astrophysics Data System (ADS)

Biological activity is a crucial soil property affecting soil sustainability and crop production. The unsuitable land management can lead to a loss in soil fertility and a reduction in the abundance and diversity of soil microorganisms. This can be as a consequence of high erosion rates due to the mismanagement of farmers (Cerdŕ et al., 2009a). However ecological practices and some organic amendments can promote the activities of soil microbial communities, and increase its biodiversity (García-Orenes et al., 2010; 2013). The impact of land use in microbiological properties of agriculture soil are presented and discussed in this review. Biological activity is quantified by microbial soil communities and soil enzyme activities to interpret the effects of soil management practices (Morugán-Coronado et al., 2013). The aim of biological activity tests is to give a reliable description of the state of agricultural soils under the effect of different land uses. Numerous methods have been used to determine the impact of land uses on microbiological properties. The current used methods for detecting microbial diversity are based on molecular techniques centered on the 16S and 18S rRNA encoding sequences such as CLPP: community-level physiological profiles; T-RFLP: terminal restriction fragment length polymorphism; DGGE: denaturing gradient gel electrophoresis; OFRG: oligonucleotide fingerprinting of rRNA genes, ARISA: Automated Ribosomal intergenic spacer analysis, SSCP: single-strand conformation polymorphism. And techniques based on the cellular composition of the microbes such as PLFA: phospholipid fatty acid analysis. Other methods are based on the activity of microbes, for example, Cmic: microbial biomass carbon; SIR: substrate induced respiration; BSR: Basal soil respiration; qCO2 metabolic quotient; enzymatic activities (Urease, ß-glucosidase and phosphatase) (Deng, 2012). Agricultural land management can contribute to increased rates of erosion due to desiccation, mechanical destruction, soil compaction, reduce pore volume, and disruption of access to food resources (Cerdŕ et al., 2009b). Furthermore, it can lead to a loss in soil fertility and reduction in the abundance and diversity of soil microorganism (Caravaca et al., 2002). Nevertheless, some organic fertilizers, such as manure, waste water and sewage sludge, promote the activities of soil microbial communities (Morugán-Coronado et al., 2011; Balota et al., 2013; Macci et al., 2013). On the other hand, land use influences soil microbial processes by changing the quantity and quality of plant residues entering the soil and their spatial distribution, thorough changes in nutrients and inputs (García-Orenes et al., 2009; 2012). The abuse of pesticides can drastically modify the function and structure of microbial communities, altering the terrestrial ecosystems, which has important implication for soil quality (Pampulha et al., 2006). Soil quality is important for the sustainable development of terrestrial ecosystem (Paz-Ferreiro & Fu, 2013; Vasconcellos et al., 2013). This paper will review the State-of-the-Art of the scientific knowledge on the impact of land use on the biological activity in agriculture soils Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and RECARE supported this research. References Balota, E. L., Yada, I.F., Amaral, H., Nakatani, A.S., Dick, R.P., Coyne, M.S. 2013. Long-term land use influences soil microbial biomass p and s, phosphatase and arylsulfatase activities, and mineralization in a brazilian oxisol. Land degradation & development. DOI: 10.1002/ldr.2242 Caravaca F, Masciandaro G, Ceccanti B. 2002. Land use in relation to soil chemical and biochemical properties in a semiarid Mediterranean environment. Soil and Tillage Research 68: 23-30. Cerdŕ, A., Flanagan, D.C., le Bissonnais, Y., Boardman, J. 2009a. Soil erosion and agriculture Soil and Tillage Research 106, 107-108. DOI: 10.1016/j.still.2009.1 Cerdŕ, A., Giménez-Morera, A.G., Bodí, M.B. 2009b. Soil and water losses from new citrus orchards

Morugán-Coronado, Alicia; Cerdŕ, Artemi; García-Orenes, Fuensanta

2014-05-01

18

Organic matter and biological activity of postagrogenic soils in the southern taiga using the example of Kostroma oblast  

NASA Astrophysics Data System (ADS)

The dynamics of the humus status (some indices) and the biological activity of agrosoddy-podzolic soils in the course of the natural forest regeneration were studied based on the example of the soils of two succession series, which differed both in their parent rock and the history of their development. Upon the overgrowing of the croplands, the humus content increased, and its distribution within the soil profile became more differentiated. As a hayfield was overgrown, the humus content decreased to some extent at the earliest stages. The parameters of the humus status more clearly changed in the succession series with the light-textured soils, which had a relatively simple history of agricultural development. The biological activity mainly decreased at the earlier succession stages and became higher with the increasing productivity and greater amounts of easily decomposing falloff entering the soil. This relationship was especially distinctly revealed in the grass communities.

Vladychenskii, A. S.; Telesnina, V. M.; Rumyantseva, K. A.; Chalaya, T. A.

2013-05-01

19

Assessing the biological activity of oil-contaminated soddy-podzolic soils with different textures  

NASA Astrophysics Data System (ADS)

The respiratory activity features in oil-contaminated soddy-podzolic soils of different textures have been studied. Unidirectional processes occur in contaminated loamy and loamy sandy soddy-podzolic soils; their intensities depend on the soil parameters. The mineralization rates of the oil products and the activity of the microflora in loamy soils exceed the corresponding parameters for loamy sandy soils. The long-term impact of oil and its transformation products results in more important disturbances of the microbial community in light soils. It has been shown that light soils containing 9% oil require longer time periods or more intensive remediation measures for the restoration of soil microbial cenoses disturbed by the pollutant.

Vershinin, A. A.; Petrov, A. M.; Akaikin, D. V.; Ignat'ev, Yu. A.

2014-02-01

20

Water-soluble organic matter and biological activity of a degraded soil amended with pig slurry  

Microsoft Academic Search

The effects of pig slurry (PS) addition at rates of 30, 90 and 150 m3 ha?1 per year for five consecutive years on total organic C (TOC), water-soluble organic C (WSOC), soil microbial biomass C (MBC), basal respiration (BR) and dehydrogenase (DEH) and ?-glucosidase (GLU) activities of soil were investigated in a field experiment conducted under barley cultivation and semiarid conditions.

Diana Hernández; José M. Fernández; César Plaza; Alfredo Polo

2007-01-01

21

Bulk soil and rhizosphere bacterial community PCR–DGGE profiles and ?-galactosidase activity as indicators of biological quality in soils contaminated by heavy metals and cultivated with Silene vulgaris (Moench) Garcke  

Microsoft Academic Search

The biological quality of two heavy metal contaminated soils (soil C: Typic Calcixerept, pH 8.3 and soil H: Typic Haploxeraf, pH 7.3) was investigated after growing the metal-tolerant plant Silene vulgaris (Moench) Garcke for two vegetative periods. The activity of the enzyme ?-galactosidase, which is sensitive to the presence of contaminants in soil, and the polymerase chain reaction-denaturing gradient gel

M. J. Martínez-Ińigo; A. Pérez-Sanz; I. Ortiz; J. Alonso; R. Alarcón; P. García; M. C. Lobo

2009-01-01

22

Engelmann Spruce (Picea engelmannii) as a biological monitor of changes in soil metal loading related to past mining activity  

USGS Publications Warehouse

Engelmann spruce (Picea engelmannii) is the dominant tree species in many abandoned mine areas of the Rocky Mountains. It is long-lived, and therefore, may act as a long term biological monitor of changes in soil chemistry caused by past mining activity. In this study, laser ablation inductively coupled mass spectrometry (LA-ICPMS) was used to analyze individual tree rings of Engelmann spruce for Fe, Zn, Cu, Cd, Mn, Pb and Sr concentrations. Cores were obtained from trees growing in tailings-impacted and control (non-tailings impacted) sites near the Waldorf mine (Waldorf, CO, USA). Zinc, Cu, Fe, Cd, Pb and Sr concentrations remained low and consistent over time in the control tree rings. However, in the tailings impacted cores, concentrations of Zn, Cu, Fe and Cd increase significantly in post-mining rings. In addition, Zn, Cu, Fe, and Cd concentrations in pre-mining rings of both the control and tailings impacted cores are similar, indicating that present day soil concentrations of these elements in the control area are a reasonable estimation of background for this area. Lead and Sr concentrations in control and tailings-impacted rings remained similar and relatively constant through time and are not useful in determining changes in soil chemistry due to past mining activity. ?? 2004 Elsevier Ltd. All rights reserved.

Witte, K. M.; Wanty, R. B.; Ridley, W. I.

2004-01-01

23

Response of Biological Soil Crusts to Porewater Metal Additions  

NASA Astrophysics Data System (ADS)

Nitrogen fixation activity of biological soil crust varied with the additon of nitrogen, molybdenum, and vanadium. Metal concetrations were measured in the soil porewater to determin how organisms affect the availability of added nutrients.

Alexander, K.; Lui, K.; Viliborghi, T.; Anbar, A.; Garcia-Pichel, F.; Hartnett, H. E.

2010-04-01

24

Biological Soil Crusts of Australia  

Microsoft Academic Search

\\u000a Biological soil crusts and their constituent organisms are common components of landscapes in semiarid and arid Australia\\u000a (Chap. 1, Photos 57–59; Rogers 1982; Eldridge and Tozer 1997a). Crusts are generally restricted to rangelands, which occupy nearly three-quarters of the land area of Australia. The soils\\u000a in this landscape are exceptionally old, and are generally shallow, infertile, and highly weathered. Rainfall

D. J. Eldridge

25

FATE OF PAH COMPOUNDS IN TWO SOIL TYPES: INFLUENCE OF VOLATILIZATION, ABIOTIC LOSS, AND BIOLOGICAL ACTIVITY  

EPA Science Inventory

The fate of 14 polycyclic aromatic hydrocarbon (PAH) compounds was evaluated with regard to interphase transfer potential and mechanisms of treatment in soil under unsaturated conditions. Volatilization and abiotic and biotic fate of the PAHs were determined using two soils not p...

26

FATE OF PAH COMPOUNDS IN TWO SOIL TYPES: INFLUENCE OF VOLATILIZATION, ABIOTIC LOSS AND BIOLOGICAL ACTIVITY  

EPA Science Inventory

The fate of 14 polycyclic aromatic hydrocarbon (PAH) compounds was evaluated with regard to interphase transfer potential and mechanisms of treatment in soil under unsaturated conditions. olatilization and abiotic and biotic fate of the PAHs were determined using two soils not pr...

27

Soil Biology & Biochemistry 39 (2007) 27012711 Carbon structure and enzyme activities in alpine and forest ecosystems  

E-print Network

pyrolysis-gas chromatography/mass spectrometry to analyze the molecular structure of light and heavy: Pyrolysis-gas chromatography/mass spectrometry; Py-GC/MS; Enzymes; Microbe; Carbon; Chemistry; Soil organic

Neff, Jason

28

Biological diversity, soils, and economics  

SciTech Connect

Terrestrial biological diversity is supported by solar energy captured by plants growing in soil. This soil-based plant productivity also provides the foundation for human societies through production of food and renewable forms of energy. Variations in plant productivity, resulting from differences in inherent soil fertility, variations in climate and weather, and differences in chemical inputs and agricultural practices, produce patterns of biological diversity that are associated with the agricultural component of economic productivity. Ecological processes lead to a generally negative relation between the diversity of plant species and potential agricultural productivity at both local and global scales. One implication of this negative relation is that preservation of areas of high plant biodiversity does not require the sacrifice of productive agricultural lands.

Huston, M. (Oak Ridge National Laboratory, TN (United States))

1993-12-10

29

A comparison of soil climate and biological activity along an elevation gradient in the eastern Mojave Desert  

USGS Publications Warehouse

Soil temperature, moisture, and CO2 were monitored at four sites along an elevation transect in the eastern Mojave Desert from January to October, 1987. Climate appeared to be the major factor controlling CO2 partial pressures, primarily through its influence of rates of biological reactions, vegetation densities, and organic matter production. With increasing elevation, and increasing actual evapotranspiration, the organic C, plant density, and the CO2 content of the soils increased. Between January and May, soil CO2 concentrations at a given site were closely related to variations in soil temperature. In July and October, temperatures had little effect on CO2, presumably due to low soil moisture levels. Up to 75% of litter placed in the field in March was lost by October whereas, for the 3 lower elevations, less than 10% of the litter placed in the field in April was lost through decomposition processes. ?? 1989 Springer-Verlag.

Amundson, R. G.; Chadwick, O. A.; Sowers, J. M.

1989-01-01

30

Effects of heavy metal concentrations on biological activity of soil micro-organisms  

Microsoft Academic Search

The distribution of cadmium, lead and zinc in exchangeable, organic, and 2M HNO3-extractable fractions as well as the effect of heavy metal concentrations on soil microflora was investigated. Six sampling transects were chosen in the Litav- ka River alluvium in 1999-2001. Concentrations of all metals increased with decreasing distance from the source of con- tamination. The concentrations of Cd and

M. Šmejkalová; O. Mikanová; L. Bor?vka

31

Biological activity of soddy-calcareous soils and cultural layers in Alanian settlements of the Kislovodsk basin  

NASA Astrophysics Data System (ADS)

Microbiological investigations of cultural layers were performed in a settlement of the Alanian culture—Podkumskoe-2 (the 2nd-4th centuries AD). The present-day soddy-calcareous soils (rendzinas) used for different purposes were also studied near this settlement. The most significant changes in the initial characteristics of the soil microbial communities occurred under the residential influence more than 1500 years ago; these changes have been preserved until the present time. In the areas subjected to the anthropogenic impact, the total microbial biomass (the weighted average of 3720 ?g C/g soil) was lower than that in the background soil. The minimal values of the microbial biomass were found in the soil of the pasture—2.5 times less than in the background soil. The urease activity of the cultural layer was higher than that of the soils nearby the settlement. Elevated values of the cellulose activity were also recorded only in the cultural layers. The current plowing has led to a significant decrease in the mycelium biomass of the microscopic fungi. In the soil of the fallow, the weighted average value of the fungal hyphae biomass along the profile was twice lower than that in the background soil and cultural layers of the settlement. The pasture first affected the active microbial biomass and, to a lesser extent, the amount of microscopic fungi.

Chernysheva, E. V.; Kashirskaya, N. N.; Korobov, D. S.; Borisov, A. V.

2014-09-01

32

Bulk soil and rhizosphere bacterial community PCR-DGGE profiles and beta-galactosidase activity as indicators of biological quality in soils contaminated by heavy metals and cultivated with Silene vulgaris (Moench) Garcke.  

PubMed

The biological quality of two heavy metal contaminated soils (soil C: Typic Calcixerept, pH 8.3 and soil H: Typic Haploxeraf, pH 7.3) was investigated after growing the metal-tolerant plant Silene vulgaris (Moench) Garcke for two vegetative periods. The activity of the enzyme beta-galactosidase, which is sensitive to the presence of contaminants in soil, and the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles of 16S rRNA gene fragments of culturable bacteria from bulk soil and rhizosphere were determined. The microbial enzymatic activity was higher in planted soils than in bare soils at the contamination level of 600 mg of total heavy metals kg(-1) soil. After growing S. vulgaris, beta-galactosidase activity was almost recovered in the calcareous soil. In this soil new bands appeared in the PCR-DGGE profiles of the rhizosphere bacterial community as a response to the exposure to heavy metals. PMID:19345981

Martínez-Ińigo, M J; Pérez-Sanz, A; Ortiz, I; Alonso, J; Alarcón, R; García, P; Lobo, M C

2009-06-01

33

Changes in the biological activity of chestnut soils upon the long-term application of fertilizers in a rotation with oil-bearing crops  

NASA Astrophysics Data System (ADS)

Experimental studies showed that irrigated chestnut soils on the piedmont of the Zailiiskiy Alatau Range are characterized by the moderate activity of the hydrolytic and redox enzymes. The use of these soils in the crop rotation system increases the hydrolytic activity of the enzymes (invertase, urease, and ATP synthase) by 30% in comparison with the monoculture; at the same time, it does not have a significant impact on the changes in the biological activity of the redox enzymes (catalase and dehydrogenase). The hydrolytic activity of the soils is activated to a greater extent in the crop rotation and in the monoculture against the background application of organic fertilizers. In this case, the recommended rates of mineral fertilizers do not inhibit the activity of the hydrolytic and redox enzymes. An increase in the hydrolytic activity of the enzymes directly affects the yield of oilseed flax. Therefore, indices of the hydrolytic activity of soils can be used as a test for the diagnostics of the efficiency of fertilizers both in crop rotation and monoculture systems.

Eleshev, R. E.; Bakenova, Z. B.

2012-11-01

34

Biological activity in metal-contaminated calcareous agricultural soils: the role of the organic matter composition and the particle size distribution.  

PubMed

Organic matter (OM) plays a key role in microbial response to soil metal contamination, yet little is known about how the composition of the OM affects this response in Mediterranean calcareous agricultural soils. A set of Mediterranean soils, with different contents and compositions of OM and carbonate and fine mineral fractions, was spiked with a mixture of Cd, Cu, Pb, and Zn and incubated for 12 months for aging. Microbial (Biolog Ecoplates) and enzyme activities (dehydrogenase, DHA; ?-galactosidase, BGAL; phosphatase, PHOS; and urease, URE) were assessed and related to metal availability and soil physicochemical parameters. All enzyme activities decreased significantly with metal contamination: 36-68 % (DHA), 24-85 % (BGAL), 22-72 % (PHOS), and 14-84 % (URE) inhibitions. Similarly, catabolic activity was negatively affected, especially phenol catabolism (?86 % compared to 25-55 % inhibition for the rest of the substrates). Catabolic and DHA activities were negatively correlated with ethylenediaminetetraacetic acid (EDTA)-extractable Cd and Pb, but positively with CaCl2, NaNO3, and DTPA-extractable Cu and Zn. Soluble OM (water- and hot-water-soluble organic C) was positively related to enzyme and catabolic activities. Recalcitrant OM and fine mineral fractions were positively related to BGAL and PHOS. Conversely, catabolic activity was negatively related to clay and positively to silt and labile OM. Results indicate that the microbial response to metal contamination is highly affected by texture and OM composition. PMID:24477337

Martin Calvarro, Luisa; de Santiago-Martín, Ana; Quirós Gómez, Javier; González-Huecas, Concepción; Quintana, Jose R; Vázquez, Antonio; Lafuente, Antonio L; Rodríguez Fernández, Teresa M; Ramírez Vera, Rosalía

2014-05-01

35

An Introduction to Biological Soil Crusts  

NSDL National Science Digital Library

Biological soil crusts are the feature of this USGS Canyonlands Research Station website. The site provides an introduction to biological soil crusts with linked images, divided into the following topics: nomenclature of the crusts- crytogamic, microbiotic, crytobiotic, and microphytic crusts, structure and formation, species composition, ecological functions, response to disturbance, future, and a glossary. In addition, the site provides links to other Canyonlands Research Station webages including an advanced page with a downloadable 90-page report on soil crusts, a gallery of biological soil crust images and figures, references, the Canyon Country Ecosystems Research Site (CCERS), and other related links.

Station, Usgs C.; Usgs

36

Just For Kids: Soil Biological Communities  

NSDL National Science Digital Library

This site explains what soil is and why it is important, describes some of the organisms that live in the soil and how they interact to provide food for plants and for each other, illustrates the food cycle, and provides soil facts in different contexts. There is an Adopt a Soil Critter section and a soil quiz. Activities include coloring, collecting bugs, observing soil color and texture, and making an earthworm farm.

37

The non destructive determination of iodine in soils and biological materials by high energy gamma-photon activation  

Microsoft Academic Search

A non destructive high energy gamma photon activation technique has been developed for the determination of iodine in a wide\\u000a range of natural materials. Results are presented and compared with those obtained by independent analytical techniques. Studies\\u000a of the loss of iodine from soils on heating are also presented. The sensitivity and precision of the technique are discussed\\u000a and its

D. R. Williams; J. S. Hislop

1977-01-01

38

Soil invertebrate activity in biological crusts on tropical inselbergs A.VAULIK, C. KOUNDA-KIKI, C. SARTHOU & J.F. PONGE  

E-print Network

for plants. Soil animals and humus components were investigated in cyanobacterial crusts close to patches plant species. In later stages of soil hal-00497120,version1-2Jul2010 #12;3 development, organic matter and biological crusts and whether they affect the genesis of the soil. Do they contribute to the accumulation of

Paris-Sud XI, Université de

39

Biological Soil Crusts of North America  

Microsoft Academic Search

\\u000a Biological soil crusts in North America are diverse and found in many different habitats. On a broad scale, there are several\\u000a different vegetation zones or ecoregions in western North America that contain biological soil crusts as major components\\u000a (Fig. 2.1, Table 2.1). These include hot deserts (Mojave, Chihuahuan, Sonoran; see Chap. 1, Photos 34, 35), cool deserts (Great\\u000a Basin, Colorado

R. Rosentreter; J. Belnap

40

Modification of soil microbial activity and several hydrolases in a forest soil artificially contaminated with copper  

Microsoft Academic Search

Soils have long been exposed to the adverse effects of human activities, which negatively affect soil biological activity. As a result of their functions and ubiquitous presence microorganisms can serve as environmental indicators of soil pollution. Some features of soil microorganisms, such as the microbial biomass size, respiration rate, and enzyme activity are often used as bioindicators of the ecotoxicity

Rosa Bellas; Ma Carmen Leirós; Fernando Gil-Sotres; Carmen Trasar-Cepeda

2010-01-01

41

Effects of chemical, biological, and physical aging as well as soil addition on the sorption of pyrene to activated carbon and biochar.  

PubMed

In this study, the suitability of biochar and activated carbon (AC) for contaminated soil remediation is investigated by determining the sorption of pyrene to both materials in the presence and absence of soil and before as well as after aging. Biochar and AC were aged either alone or mixed with soil via exposure to (a) nutrients and microorganisms (biological), (b) 60 and 110 °C (chemical), and (c) freeze-thaw cycles (physical). Before and after aging, the pH, elemental composition, cation exchange capacity (CEC), microporous SA, and sorption isotherms of pyrene were quantified. Aging at 110 °C altered the physicochemical properties of all materials to the greatest extent (for example, pH increased by up to three units and CEC by up to 50% for biochar). Logarithmic K(Fr) values ranged from 7.80 to 8.21 (ng kg(-1))(ng L(-1))(-nF) for AC and 5.22 to 6.21 (ng kg(-1))(ng L(-1))(-nF) for biochar after the various aging regimes. Grinding biochar to a smaller particle size did not significantly affect the sorption of d(10) pyrene, implying that sorption processes operate on the subparticle scale. Chemical aging decreased the sorption of pyrene to the greatest extent (up to 1.8 log unit for the biochar+soil). The sorption to AC was affected more by the presence of soil than the sorption to biochar was. Our results suggest that AC and biochar have a high sorption capacity for pyrene that is maintained both in the presence of soil and during harsh aging. Both materials could therefore be considered in contaminated land remediation. PMID:22077986

Hale, Sarah E; Hanley, Kelly; Lehmann, Johannes; Zimmerman, Andrewr; Cornelissen, Gerard

2011-12-15

42

Effects of Heavy Metals on Soil Enzyme Activities  

Microsoft Academic Search

The pollution of the soil with heavy metals is one of the worst legacies of our intensive agricultural–industrial activities,\\u000a and it negatively affects various characteristics of the soil, including soil enzyme activities. Soil enzymes are natural\\u000a molecules that catalyze soil microbial reactions and mainly originate from microorganisms and plants. Since enzyme activities\\u000a play fundamental roles in soil chemical and biological

Ayten Karaca; Sema Camci Cetin; Oguz Can Turgay; Ridvan Kizilkaya

43

The role of biological soil crusts on soil moisture  

NASA Astrophysics Data System (ADS)

In water-limited ecosystems, water becomes the most important driver for plant productivity. In these systems, spatial distribution of water resources is not random but organized into a mosaic of water-depletion areas linked to water-accumulation areas. In other words, water is transferred from interplant patches that act as source areas to vegetation patches that act as sinks of this resource. Thus, structure and functioning of interplant patches have a decisive role in water redistribution and distribution patterns of vegetation. Soil surface in the interplant spaces of most arid and semiarid ecosystems is covered by biological soil crusts (BSCs). These organisms regulate water fluxes into and through soils and play major roles in local hydrological processes. In the last years, the role of these organisms in infiltration and runoff has gained increased importance and a better knowledge about their effects on these processes has been acquired. However, the role of BSCs in other important components of the water balance such as evaporation or soil moisture has been scarcely studied, so that their effects on these processes remain unknown. The objective of this work is to examine the influence of BSCs on soil moisture regimes in the top profile of the soil in two semiarid ecosystems of SE Spain with contrasting soil texture and where BSCs are well-represented. Soil moisture content at 0.03 and 0.10 m was monitored under two representative types of BSCs, a dark cyanobacteria-dominated BSC and a light-coloured lichen-dominated BSC, and in soils where these BSCs were removed by scraping, at both study sites. Our results show that, under high water conditions, removal of BSCs leads to a decrease in soil moisture compared to soils covered by BSCs. Decrease in soil moisture due to BSC removal namely affects moisture in the upper layer of the soil (0.03 m), but has little impact in deeper soil (0.10 m). Evaporation is also generally faster in soils with no BSCs than in soils covered by them. The type of BSC influences soil moisture in a different way depending on soil water conditions. Under high water content conditions, soil water loss is faster and soil moisture content lower under cyanobacterial than under lichen BSCs, due to higher infiltration promoted by lichens. On the contrary, under low water content conditions, lichen-crusted soils dry out faster and exhibit less moisture than cyanobacteria-crusted ones, attributed to the larger porosity and subsequent greater evaporative losses in lichen- than in cyanobacteria-crusted soils. We found higher moisture in coarse-textured soils than in fine-textured ones, despite the higher water retention capacity of the latter soils. More favourable conditions in the coarser soils, which had greater organic matter content, aggregate stability and were subject to less water stress due to its proximity to the coast, seems to contribute to this increased soil moisture content. BSCs therefore play an important role on the maintenance of water availability in the interplant spaces, thereby strongly affecting soil physical and biological processes, and the potential for emergence establishment and survival of plants in semiarid ecosystems.

Chamizo, S.; Cantón, Y.; Lázaro, R.; Rodriguez-Caballero, E.; Domingo, F.

2012-04-01

44

Soil transport driven by biological processes over millennial time scales  

Microsoft Academic Search

Downslope soil transport in the absence of overland flow has been attributed to numerous mechanisms, including particle-by-particle creep and disturbances associated with biological activity. Process stochasticity and difficulties associated with field measurement have obscured the characterization of relevant long-term soil transport rates and mechanisms. In a series of incised fluvial terraces along the Charwell River, South Island, New Zealand, we

Joshua J. Roering; Peter Almond; Philip Tonkin; James McKean

2002-01-01

45

Soil organic matter distribution and microaggregate characteristics as affected by agricultural management and earthworm activity  

E-print Network

within earthworm casts. Soil Biology and Biochemistry, 37,Earthworms and rate of break- down of soybean and maize residues in soil. Soil Biologyearthworm activity in a marine silt loam under pasture versus arable land. Biology

Pulleman, M M; Six, J; van Breemen, N; Jongmans, A G

2005-01-01

46

Biological interactions between soil nitrogen and alkaline-hydrolysing nitrogen fertilizers  

Microsoft Academic Search

Added N interactions were measured in four soil incubated with 15N-labelled urea or diammonium phosphate. The use of biologically active, ?-irradiated, or reinoculated ?-irradiated samples allowed us to separate added N interactions due to chemical and biological processes, and to distinguish real interactions from apparent effects. Real biologically mediated added N interactions were observed in one soil for both fertilizer

S. Sen; P. M. Chalk

1995-01-01

47

Soil Biology & Biochemistry 38 (2006) 16081614 Endogeic earthworms differentially influence bacterial communities  

E-print Network

Soil Biology & Biochemistry 38 (2006) 1608­1614 Endogeic earthworms differentially influence C. Rilliga , Johan Sixb a Division of Biological Sciences, Microbial Ecology Program, The University November 2005 Available online 2 February 2006 Abstract Endogeic earthworm activities can strongly

Rilli, Matthias C.

48

Biological residues define the ice nucleation properties of soil dust  

NASA Astrophysics Data System (ADS)

Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nuclei per unit mass active in the immersion freezing mode at -12 °C than montmorillonite, the most efficient pure clay mineral. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.

Conen, F.; Morris, C. E.; Leifeld, J.; Yakutin, M. V.; Alewell, C.

2011-06-01

49

[Biological activity of Spirulina].  

PubMed

In this review information of Spirulina platensis (SP), a blue-green alga (photosynthesizing cyanobacterium) having diverse biological activity is presented. Due to high content of highly valuable proteins, indispensable amino acids, vitamins, beta-carotene and other pigments, mineral substances, indispensable fatty acids and polysaccharides, PS has been found suitable for use as bioactive additive. SP produces an immunostimulating effect by enhancing the resistance of humans, mammals, chickens and fish to infections, the capacity of influencing hemopoiesis, stimulating the production of antibodies and cytokines. Under the influence of SP macrophages, T and B cells are activated. SP sulfolipids have proved to be effective against HIV. Preparations obtained from SP biomass have also been found active against herpesvirus, cytomegalovirus, influenza virus, etc. SP extracts are capable in inhibiting cancerogenesis. SP preparations are regarded as functional products contributing to the preservation of the resident intestinal microflora, especially lactic acid bacilli and bifidobacteria, and to a decrease in the level of Candida albicans. The biological activity of SP with respect to microorganisms holds good promise for using these microalgae as components of culture media. PMID:11548244

Blinkova, L P; Gorobets, O B; Baturo, A P

2001-01-01

50

THE EFFECT OF THE FERTILIZATION WITH VINASSA ROMPAK PRODUCT ON THE BIOLOGICAL ACTIVITY OF THE CULTIVATED SOILS  

Microsoft Academic Search

The product Vinassa Rompak, resulted in the yeast obtaining technology process, can be a good fertilizer for agricultural crops and a factor for maintaining the balance between the microorganisms populations from the soil. The experiment regarding the infl uence of fertilization by using the Vinassa Rompak product was made on two permanent growing; a permanent pasturelands and fodder beet. The

E. ULEA; Isabela ILISESCU; Aliona MOCANU; D. SAVA

51

Nocardiopsis and Saccharothrix genera in Saharan soils in Algeria: Isolation, biological activities and partial characterization of antibiotics  

Microsoft Academic Search

Twenty-five soil samples were collected in the Algerian Sahara and analyzed to isolate rare actinomycetes. Eighty-six isolates with the same Nocardiopsis or Saccharothrix morphology were isolated on humic–vitamin B agar medium using dilution techniques and several antibiotics as selective agents. Certain of these antibiotics seemed to be very selective for some phenotypes. Morphological and chemotaxonomic characteristics led to identifying 54

Abdelghani Zitouni; Hadjira Boudjella; Lynda Lamari; Boubekeur Badji; Florence Mathieu; Ahmed Lebrihi; Nasserdine Sabaou

2005-01-01

52

The Effect of Biological Soil Crusts on Throughput of Rainwater and N into Lake Michigan Sand Dune Soils  

Microsoft Academic Search

Biological soil crusts composed of cyanobacteria, green algae, bryophytes, and lichens colonize soils in arid and semiarid\\u000a ecosystems worldwide and are responsible for significant N input to the soils of these ecosystems. Soil crusts also colonize\\u000a active sand dunes in more humid regions, but studies of structure and function of such sand dune crusts are lacking. We identified\\u000a the cyanobacterial,

Rachel K. Thiet; R. E. J. Boerner; Moria Nagy; Richard Jardine

2005-01-01

53

The use of biological activities to monitor the removal of fuel contaminants—perspective for monitoring hydrocarbon contamination: a review  

Microsoft Academic Search

Soil biological activities are vital for the restoration of soil contaminated with hydrocarbons. Their role includes the biotransformation of petroleum compounds into harmless compounds. In this paper, the use of biological activities as potential monitoring tools or bioindicators during bioremediation of hydrocarbon-contaminated soil are reviewed. The use of biological activities as bioindicators of hydrocarbon removal in soil has been reported

Mphekgo P. Maila; Thomas E. Cloete

2005-01-01

54

Microbial Activity in Frozen Soils  

Microsoft Academic Search

This chapter is a review on metabolic activity of microorganisms in permafrost and frozen tundra soils. Several noteworthy\\u000a limitations resulted from critical analysis of available techniques, in particular regarding soil respiration: the apparent\\u000a CO2 flux from frozen soil was shown to overestimate the actual microbial activity due to abiotic release of CO2 accumulated in the sample. Even acidic non-carbonaceous soils

Nicolai S. Panikov

55

Biological residues define the ice nucleation properties of soil dust  

NASA Astrophysics Data System (ADS)

Soil dust is a major driver of ice nucleation in clouds leading to precipitation. It consists largely of mineral particles with a small fraction of organic matter constituted mainly of remains of micro-organisms that participated in degrading plant debris before their own decay. Some micro-organisms have been shown to be much better ice nuclei than the most efficient soil mineral. Yet, current aerosol schemes in global climate models do not consider a difference between soil dust and mineral dust in terms of ice nucleation activity. Here, we show that particles from the clay and silt size fraction of four different soils naturally associated with 0.7 to 11.8 % organic carbon (w/w) can have up to four orders of magnitude more ice nucleation sites per unit mass active in the immersion freezing mode at -12 °C than montmorillonite, the nucleation properties of which are often used to represent those of mineral dusts in modelling studies. Most of this activity was lost after heat treatment. Removal of biological residues reduced ice nucleation activity to, or below that of montmorillonite. Desert soils, inherently low in organic content, are a large natural source of dust in the atmosphere. In contrast, agricultural land use is concentrated on fertile soils with much larger organic matter contents than found in deserts. It is currently estimated that the contribution of agricultural soils to the global dust burden is less than 20 %. Yet, these disturbed soils can contribute ice nuclei to the atmosphere of a very different and much more potent kind than mineral dusts.

Conen, F.; Morris, C. E.; Leifeld, J.; Yakutin, M. V.; Alewell, C.

2011-09-01

56

Roles of organic soil amendments and soil organisms in the biological control of plant-parasitic nematodes: a review  

Microsoft Academic Search

Organic soil amendments stimulate the activities of microorganisms that are antagonistic to plant-parasitic nematodes. The decomposition of organic matter results in accumulation in the soils of specific compounds that may be nematicidal. Amendments are mainly bio-products and wastes from industrial, agricultural, biological and other activities. Control of plant-parasitic nematodes can be by improvements of soil structure and fertility, alteration of

Mohammad Akhtar; Abdul Malik

2000-01-01

57

Effects of soil type and farm management on soil ecological functional genes and microbial activities.  

PubMed

Relationships between soil microbial diversity and soil function are the subject of much debate. Process-level analyses have shown that microbial function varies with soil type and responds to soil management. However, such measurements cannot determine the role of community structure and diversity in soil function. The goal of this study was to investigate the role of gene frequency and diversity, measured by microarray analysis, on soil processes. The study was conducted in an agro-ecosystem characterized by contrasting management practices and soil types. Eight pairs of adjacent commercial organic and conventional strawberry fields were matched for soil type, strawberry variety, and all other environmental conditions. Soil physical, chemical and biological analyses were conducted including functional gene microarrays (FGA). Soil physical and chemical characteristics were primarily determined by soil textural type (coarse vs fine-textured), but biological and FGA measures were more influenced by management (organic vs conventional). Organically managed soils consistently showed greater functional activity as well as FGA signal intensity (SI) and diversity. Overall FGA SI and diversity were correlated to total soil microbial biomass. Functional gene group SI and/or diversity were correlated to related soil chemical and biological measures such as microbial biomass, cellulose, dehydrogenase, ammonium and sulfur. Management was the dominant determinant of soil biology as measured by microbial gene frequency and diversity, which paralleled measured microbial processes. PMID:20376100

Reeve, Jennifer R; Schadt, Christopher W; Carpenter-Boggs, Lynne; Kang, Sanghoon; Zhou, Jizhong; Reganold, John P

2010-09-01

58

METHOD FOR SCALING BIOLOGICAL RESPONSE OF SOIL MICROCOSMS  

EPA Science Inventory

An extensive series of laboratory experiments was conducted in soil microcosms to study the respiratory response of microorganisms to toxicant amendments within different types of soils. Our analysis of test results demonstrates that coupled biological and environmental factors w...

59

Nitrogen fixation by biological soil crusts and heterotrophic bacteria in an intact Mojave Desert ecosystem with elevated CO 2 and added soil carbon  

Microsoft Academic Search

Fixation of N by biological soil crusts and free-living heterotrophic soil microbes provides a significant proportion of ecosystem N in arid lands. To gain a better understanding of how elevated CO2 may affect N2-fixation in aridland ecosystems, we measured C2H2 reduction as a proxy for nitrogenase activity in biological soil crusts for 2yr, and in soils either with or without

S. A. Billings; S. M. Schaeffer; R. D. Evans

2003-01-01

60

Effects of amendment of different biochars on soil physical and biological properties related to carbon mineralization  

NASA Astrophysics Data System (ADS)

Biochar addition to soils potentially affects various soil properties, and these effects are dependent on biochars derived from different feedstock materials and pyrolysis processes. The objective of this study was to investigate the effects of amendment of different biochars on soil physical and biological properties. Biochars were produced with dairy manure and woodchip at temperatures of 300, 500, and 700°C, respectively. Each biochar was mixed at 5% (w/w) with a forest soil and the mixture was incubated for 180 days, during which soil physical and biological properties, and soil respiration rates were measured. Results showed that the biochar addition significantly enhanced the formation of soil macroaggregates at the early incubation time. The biochar application significantly reduced soil bulk density, increased the amount of soil organic matter, and stimulated microbial activity and soil respiration rates at the early incubation stage. Biochar applications improved water retention capacity, with stronger effects by biochars produced at higher pyrolysis temperatures. At the same suction, the soil with woodchip biochars possessed higher water content than with the dairy manure biochars. Biochar addition significantly affected the soil physical and biological properties, which resulted in different soil carbon mineralization rates.

Zhang, Renduo; Zhu, Shuzhi; Ouyang, Lei

2014-05-01

61

Evaporative losses from soils covered by physical and different types of biological soil crusts  

USGS Publications Warehouse

Evaporation of soil moisture is one of the most important processes affecting water availability in semiarid ecosystems. Biological soil crusts, which are widely distributed ground cover in these ecosystems, play a recognized role on water processes. Where they roughen surfaces, water residence time and thus infiltration can be greatly enhanced, whereas their ability to clog soil pores or cap the soil surface when wetted can greatly decrease infiltration rate, thus affecting evaporative losses. In this work, we compared evaporation in soils covered by physical crusts, biological crusts in different developmental stages and in the soils underlying the different biological crust types. Our results show that during the time of the highest evaporation (Day 1), there was no difference among any of the crust types or the soils underlying them. On Day 2, when soil moisture was moderately low (11%), evaporation was slightly higher in well-developed biological soil crusts than in physical or poorly developed biological soil crusts. However, crust removal did not cause significant changes in evaporation compared with the respective soil crust type. These results suggest that the small differences we observed in evaporation among crust types could be caused by differences in the properties of the soil underneath the biological crusts. At low soil moisture (<6%), there was no difference in evaporation among crust types or the underlying soils. Water loss for the complete evaporative cycle (from saturation to dry soil) was similar in both crusted and scraped soils. Therefore, we conclude that for the specific crust and soil types tested, the presence or the type of biological soil crust did not greatly modify evaporation with respect to physical crusts or scraped soils.

Chamizo, S.; Cantón, Y.; Domingo, F.; Belnap, J.

2013-01-01

62

Impact of environmental factors and biological soil crust types on soil respiration in a desert ecosystem.  

PubMed

The responses of soil respiration to environmental conditions have been studied extensively in various ecosystems. However, little is known about the impacts of temperature and moisture on soils respiration under biological soil crusts. In this study, CO2 efflux from biologically-crusted soils was measured continuously with an automated chamber system in Ningxia, northwest China, from June to October 2012. The highest soil respiration was observed in lichen-crusted soil (0.93 ± 0.43 µmol m-2 s-1) and the lowest values in algae-crusted soil (0.73 ± 0.31 µmol m-2 s-1). Over the diurnal scale, soil respiration was highest in the morning whereas soil temperature was highest in the midday, which resulted in diurnal hysteresis between the two variables. In addition, the lag time between soil respiration and soil temperature was negatively correlated with the soil volumetric water content and was reduced as soil water content increased. Over the seasonal scale, daily mean nighttime soil respiration was positively correlated with soil temperature when moisture exceeded 0.075 and 0.085 m3 m-3 in lichen- and moss-crusted soil, respectively. However, moisture did not affect on soil respiration in algae-crusted soil during the study period. Daily mean nighttime soil respiration normalized by soil temperature increased with water content in lichen- and moss-crusted soil. Our results indicated that different types of biological soil crusts could affect response of soil respiration to environmental factors. There is a need to consider the spatial distribution of different types of biological soil crusts and their relative contributions to the total C budgets at the ecosystem or landscape level. PMID:25050837

Feng, Wei; Zhang, Yuqing; Jia, Xin; Wu, Bin; Zha, Tianshan; Qin, Shugao; Wang, Ben; Shao, Chenxi; Liu, Jiabin; Fa, Keyu

2014-01-01

63

Active synthetic soil  

NASA Technical Reports Server (NTRS)

A synthetic soil/fertilizer for horticultural application having all the agronutrients essential for plant growth is disclosed. The soil comprises a synthetic apatite fertilizer having sulfur, magnesium, and micronutrients dispersed in a calcium phosphate matrix, a zeolite cation exchange medium saturated with a charge of potassium and nitrogen cations, and an optional pH buffer. Moisture dissolves the apatite and mobilizes the nutrient elements from the apatite matrix and the zeolite charge sites.

Ming, Douglas W. (inventor.); Henninger, Donald L. (inventor.); Allen, Earl R. (inventor.); Golden, Dadigamuwage C. (inventor.)

1995-01-01

64

Active synthetic soil  

NASA Technical Reports Server (NTRS)

A synthetic soil/fertilizer for horticultural application having all the agronutrients essential for plant growth is disclosed. The soil comprises a synthetic apatite fertilizer having sulfur, magnesium and micronutrients dispersed in a calcium phosphate matrix, a zeolite cation exchange medium saturated with a charge of potassium and nitrogen cations, and an optional pH buffer. Moisture dissolves the apatite and mobilizes the nutrient elements from the apatite matrix and the zeolite charge sites.

Ming, Douglas W. (Inventor); Henninger, Donald L. (Inventor); Allen, Earl R. (Inventor); Golden, Dadigamuwage C. (Inventor)

1995-01-01

65

Biological and Physico-chemical Processes of Soil Organic Matter Cycling in Diverse Soils  

NASA Astrophysics Data System (ADS)

Soils comprise the largest biologically active terrestrial pool of organic carbon (OC). The top meter of soil contains 1500 Pg of OC which is 3 times that present in vegetation and two times the CO2-C present in atmosphere. Current soil C models simulate soil C pool sizes and turnover rates on post-hoc basis and the mechanisms governing soil OC cycling have not been integrated in such models. Therefore the scale of applicability and accuracy of predictions of current C models are questionable. Our current efforts are focused on developing a mechanistic framework of soil C cycling processes and its linkage to global C model. As part of this effort, we seek to understand the important cycling and interactive processes of OC compounds with the soil minerals and microbial community on a global suite of soils from temperate, tropical and arctic ecosystems. The selected OC compounds are glucose, cellulose, stearic acid and vanillic acid which are representative of SOM composition that contains 5-15% sugars, 20-50% starch, 10% proteins, 20-30% lignin and 2-5% lipids. We hypothesize that physico-chemical interactions between OC compounds and soil minerals determines the biological stability and distribution of such compounds in soils. Cycling of the selected 14C-labeled OC compounds were investigated as a function of soil type, soil depth and functional components of SOM (dissolved organic carbon, DOC; particulate organic matter, POM; and mineral associated organic matter, MAOM). This presentation will consist of the results from sorption and long-term incubation experiments conducted on diverse soils by the addition of 14C-glucose. Sorption of 14C-glucose on soil minerals was determined by batch equilibration experiments of MAOM fraction at a solid-to-solution ratio of 1:60 for 8 hours. A series of initial glucose solutions containing 0-100 mg C/L unlabeled C and 4000 dpm/ml labeled C were used. Maximum sorption capacity (Qmax) and affinity coefficient (K) were determined by fitting the experimental data to the Langmuir model. Results indicated that C sorption potential varies across different climates, soil types and soil horizons. Tropical Oxisol from Costa Rica exhibited the lowest Qmax (12 mgC kg-1) and temperate Alfisols from United States exhibited the highest Qmax (4893 mgC kg-1) for the added glucose. Another interesting finding is that the MAOM derived from the surface soil likely possess higher sorption capacity than that of subsoil. The biological cycling of C through microbes via microbial uptake and mineralization processes are currently being undertaken by monitoring the 14CO2 evolution from the long-term incubation experiments. Additionally, the evidence of priming as a result of glucose addition will also be tested and presented at the meeting. The ultimate outcome of this study is the development of a mechanistically-based and globally-relevant soils C model that is linkable into widely-used global circulation models.

Jagadamma, S.; Mayes, M. A.; Steinweg, J. M.; Post, W. M.; Wang, G.

2011-12-01

66

Fertilization regimes affect the soil biological characteristics of a sudangrass and ryegrass rotation system.  

PubMed

The sudangrass (Sorghum sudanense) and ryegrass (Lolium multiflorum L.) rotation is an intensive and new cropping system in Central China. Nutrient management practices in this rotation system may influence soil fertility, the important aspects of which are soil biological properties and quality. As sensitive soil biological properties and quality indicators, soil microbial community activity, microbial biomass, enzyme activities, soil organic matter (SOM) and total N resulting from different fertilization regimes in this rotation system were studied through a four-year field experiment from April 2005 to May 2009. Treatments included control (CK), fertilizer phosphorus and potassium (PK), fertilizer nitrogen and potassium (NK), fertilizer nitrogen and phosphorus (NP) and a fertilizer nitrogen, phosphorus and potassium combination (NPK). Soil microbial community activities in the NK, NP and NPK treatments were significantly lower than those in the CK and PK treatments after the sudangrass and ryegrass trial. The highest microbial biomass C, microbial biomass N, SOM, total N, sucrase and urease activities were found in the NPK treatment, and these soil quality indicators were significantly higher in the NK, NP and NPK treatments than in the PK and CK treatments. Soil microbial biomass and enzyme activities were positively associated with SOM in the sudangrass and ryegrass rotation system, indicating that fertilization regimes, especially N application, reduced microbial community activity in the soil. Proper fertilization regimes will increase microbial biomass, enzyme activity and SOM and improve soil fertility. PMID:21706419

Li, WenXi; Lu, JianWei; Li, FangBai; Wang, Yan; Lu, JunMing; Li, XiaoKun

2011-06-01

67

Soil Biology & Biochemistry 38 (2006) 30013002 A synthesis of soil biodiversity and ecosystem functioning in  

E-print Network

Soil Biology & Biochemistry 38 (2006) 3001�3002 Editorial A synthesis of soil biodiversity-free soils in Antarctica has exploded, drastically altering general perceptions about the diversity of life on this cold, dark and windy continent. In Victoria Land, Antarctica (701300 S to 78100S), where soil biota

Wall, Diana

68

Exchange of greenhouse gases between soil and atmosphere: interactions of soil physical factors and biological processes  

Microsoft Academic Search

Summary This review examines the interactions between soil physical factors and the biological processes respon- sible for the production and consumption in soils of greenhouse gases. The release of CO2 by aerobic respiration is a non-linear function of temperature over a wide range of soil water contents, but becomes a function of water content as a soil dries out. Some

K. A. S MITH; F. C ONEN; K. E. D OBBIE; A. R EY

2003-01-01

69

Biological activities of carrageenan.  

PubMed

Red seaweeds are popular and economically important worldwide and also well known for their medicinal effects due to the presence of phycocolloids. Carrageenans, the major phycocolloid group of red algae, have been extensively investigated for their vast array of bioactivities such as anticoagulant, antiviral, cholesterol-lowering effects, immunomodulatory activity, and antioxidant. Carrageenan possesses promising activity both in vitro and in vivo, showing promising potential to be developed as therapeutic agents. In this chapter, attempts have been made to examine the health benefit effects of carrageenans. PMID:25081080

Pangestuti, Ratih; Kim, Se-Kwon

2014-01-01

70

Molecular Biology Concepts and Activities  

NSDL National Science Digital Library

This overview reviews key concepts and learning activities to help students understand how genes influence our traits by molecular processes. Topics covered include basic understanding of the important roles of proteins and DNA; DNA structure, function and replication; the molecular biology of how genes influence traits, including transcription and translation; and the molecular biology of mutations. To help students understand the relevance of these molecular processes, the suggested learning activities link alleles of specific genes to human characteristics such as albinism, sickle cell anemia and muscular dystrophy. This overview provides links to suggested activities which include hands-on laboratory and simulation activities, web-based simulations, discussion activities and a vocabulary review game.

Waldron, Ingrid

71

Summary Soil respiration is controlled by soil temperature, soil water, fine roots, microbial activity, and soil physical and  

E-print Network

on soil car- bon storage, whereas fertilization and nitrogen-fixing vegeta- tion increase overall soilSummary Soil respiration is controlled by soil temperature, soil water, fine roots, microbial activity, and soil physical and chemical properties. Forest thinning changes soil temperature, soil water

Cohen, Ronald C.

72

Assessing Cross-disciplinary Efficiency of Soil Amendments for Agro-biologically, Economically, and Ecologically Integrated Soil Health Management  

PubMed Central

Preventive and/or manipulative practices will be needed to maintain soil's biological, physiochemical, nutritional, and structural health in natural, managed, and disturbed ecosystems as a foundation for food security and global ecosystem sustainability. While there is a substantial body of interdisciplinary science on understanding function and structure of soil ecosystems, key gaps must be bridged in assessing integrated agro-biological, ecological, economical, and environmental efficiency of soil manipulation practices in time and space across ecosystems. This presentation discusses the application of a fertilizer use efficiency (FUE) model for assessing agronomic, economic, ecological, environmental, and nematode (pest) management efficiency of soil amendments. FUE is defined as increase in host productivity and/or decrease in plant-parasitic nematode population density in response to a given fertilizer treatment. Using the effects of nutrient amendment on Heterodera glycines population density and normalized difference vegetative index (indicator of physiological activities) of a soybean cultivar ‘CX 252’, how the FUE model recognizes variable responses and separates nutrient deficiency and toxicity from nematode parasitism as well as suitability of treatments designed to achieve desired biological and physiochemical soil health conditions is demonstrated. As part of bridging gaps between agricultural and ecological approaches to integrated understanding and management of soil health, modifications of the FUE model for analyzing the relationships amongst nematode community structure, soil parameters (eg. pH, nutrients, %OM), and plant response to soil amendment is discussed. PMID:22736840

2010-01-01

73

Biological activity of ionene polymers  

NASA Technical Reports Server (NTRS)

Ionene polymers are polyammonium salts with positive nitrogens in the backbone, resulting from the polycondensation of diamines with dihalides or from the polycondensation of halo amines. The mechanism of formation of ionene polymers of different structures and their biological activity is reviewed. The antimicrobial and antifungal properties are compared with low molecular weight ammonium salts. Ionenes were found to combine with DNA by means of ionic bonds to yield similar complexes to those obtained with polyamines (spermine and spermidine). They also combine with nerve cell receptors and exercise a more powerful and longer duration ganglionic blocking action than their monomeric analogs. The antiheparin activity of ionenes and the thromboresistance of elastomeric ionene heparin coatings is described. The enhanced biological activity of ionenes as compared with low molecular weight compounds is attributed to a cooperative effect of a large number of positive charges on the polymeric chains.

Rembaum, A.

1973-01-01

74

Nitrogen Fixation and Leaching of Biological Soil Crust Communities in Mesic Temperate Soils  

E-print Network

Microbial Ecology Nitrogen Fixation and Leaching of Biological Soil Crust Communities in Mesic Temperate Soils Roberta M. Veluci1,2 , Deborah A. Neher1,3 and Thomas R. Weicht1,3 (1) Department of Earth, FL 32611-0760, USA (3) Department of Plant and Soil Science, University of Vermont, 105 Carrigan Dr

Neher, Deborah A.

75

Soil Biology & Biochemistry 39 (2007) 21382149 Heterogeneity of soil nutrients and subsurface biota  

E-print Network

Laboratory, 999-W, Aiken, SC 29808, USA f Department of Plant & Soil Science, University of Vermont, HillsAuthor's personal copy Soil Biology & Biochemistry 39 (2007) 2138­2149 Heterogeneity of soil, USA c Department of Earth, Ecological and Environmental Sciences, University of Toledo, 2801 W

Neher, Deborah A.

76

Understanding biological diversity in soil: The UK's Soil Biodiversity Research Programme  

Microsoft Academic Search

We describe the origins, development and characteristics of a major programme of research into soil biodiversity, the NERC Thematic Research Programme ‘Biological Diversity and Function in Soils’. The programme was conceived to address a number of questions relating to the role of biodiversity in the ecological functioning of soils. It had six scientific aims, which in outline were: (i) to

Michael B. Usher; Andrew R. J. Sier; Mike Hornung; Peter Millard

2006-01-01

77

Nitrogen fixation in biological soil crusts from southeast Utah, USA  

Microsoft Academic Search

Biological soil crusts can be the dominant source of N for arid land ecosystems. We measured potential N fixation rates biweekly for 2 years, using three types of soil crusts: (1) crusts whose directly counted cells were >98% Microcoleus vaginatus (light crusts); (2) crusts dominated by M. vaginatus, but with 20% or more of the directly counted cells represented by

Jayne Belnap

2002-01-01

78

Biological activity of gibberellin analogues  

Microsoft Academic Search

In order to determine the significance of the C-6 carboxyl group for the biological activity gibberellin A3, 6-epigibberellin A3, 7-norgibberellin A3, 6ß-methyl-7-norgibberellin A3, and 7-homogibberellin A3 were studied using dwarf pea, dwarf maize, dwarf rice, dwarf barley and a-amylase bioassays. All gibberellin A3(GA3)derivatives tested were considerably less active than GA3. In all biossays, 6-epi-GA3 showed a low activity of the

Ch. Bergner; M. Lischewski; G. Adam; G. Sembdner

1982-01-01

79

Using soil biomass as an indicator for the biological removal of effluent-derived organic carbon during soil infiltration.  

PubMed

This study investigates the relationship between soil biomass and organic carbon removal during the infiltration of conventionally treated effluents used for groundwater recharge during soil-aquifer treatment (SAT). Investigations were conducted on samples collected from full-scale SAT sites, revealing a positive correlation between biodegradable organic carbon (BOC) concentrations in the recharged effluents and total viable soil biomass concentrations in the infiltration zone of soil samples collected from respective recharge basins. Findings of this study suggest that BOC limits soil biomass growth and was able to support a steady-state concentration of viable soil biomass that is characteristic to BOC concentrations introduced with the recharged effluents. All investigated sites indicate that BOC is primarily removed within 30 cm soil depth leading to a significant increase in soil biomass levels (measured as substrate induced respiration (SIR), total viable biomass, and dehydrogenase activity (DHA)). Controlled biological column studies revealed that the primary components of BOC in domestic effluents are organic colloids. Findings of this study support that hydrophobic acids, commonly believed to be recalcitrant, may also be attenuated by biological processes during soil infiltration. PMID:16483630

Rauch-Williams, Tanja; Drewes, Jörg E

2006-03-01

80

Behaviour of oxyfluorfen in soils amended with edaphic biostimulants/biofertilizers obtained from sewage sludge and chicken feathers. Effects on soil biological properties.  

PubMed

We studied the behaviour of oxyfluorfen herbicide at a rate of 4 l ha(-1) on biological properties of a Calcaric Regosol amended with two edaphic biostimulants/biofertilizers (SS, derived from sewage sludge; and CF, derived from chicken feathers). Oxyfluorfen was surface broadcast on 11 March 2013. Two days after application of oxyfluorfen to soil, both biostimulants/biofertilizers (BS) were also applied to the soil. An unamended soil without oxyfluorfen was used as control. For 2, 4, 7, 9, 20, 30, 60, 90 and 120 days of the application of herbicide to the soil and for each treatment, the soil dehydrogenase, urease, ?-glucosidase and phosphatase activities were measured. For 2, 7, 30 and 120 days of the application of herbicide to the soil and for each treatment, soil microbial community was determined. The application of both BS to soil without the herbicide increased the enzymatic activities and soil biodiversity, mainly at 7 days of beginning the experiment. However, this stimulation was higher in the soil amended with SS than for CF. The application of herbicide in organic-amended soils decreased the inhibition of soil enzymatic activities and soil biodiversity. Possibly, the low-molecular-weight protein content easily assimilated by soil microorganisms is responsible for less inhibition of these soil biological properties. PMID:24859703

Rodríguez-Morgado, Bruno; Gómez, Isidoro; Parrado, Juan; Tejada, Manuel

2014-09-01

81

Nitrogen fixation and leaching of biological soil crust communities in mesic temperate soils.  

PubMed

Biological soil crust is composed of lichens, cyanobacteria, green algae, mosses, and fungi. Although crusts are a dominant source of nitrogen (N) in arid ecosystems, this study is among the first to demonstrate their contribution to N availability in xeric temperate habitats. The study site is located in Lucas County of Northwest Ohio. Using an acetylene reduction technique, we demonstrated potential N fixation for these crusts covering sandy, acidic, low N soil. Similar fixation rates were observed for crust whether dominated by moss, lichen, or bare soil. N inputs from biological crusts in northwestern Ohio are comparable to those in arid regions, but contribute substantially less N than by atmospheric deposition. Nitrate and ammonium leaching from the crust layer were quantified using ion exchange resin bags inserted within intact soil cores at 4 cm depth. Leaching of ammonium was greater and nitrate less in lichen than moss crusts or bare soil, and was less than that deposited from atmospheric sources. Therefore, biological crusts in these mesic, temperate soils may be immobilizing excess ammonium and nitrate that would otherwise be leached through the sandy soil. Moreover, automated monitoring of microclimate in the surface 7 cm of soil suggests that moisture and temperature fluctuations in soil are moderated under crust compared to bare soil without crust. We conclude that biological crusts in northwestern Ohio contribute potential N fixation, reduce N leaching, and moderate soil microclimate. PMID:16453200

Veluci, Roberta M; Neher, Deborah A; Weicht, Thomas R

2006-02-01

82

The influence of carbonates in parent rocks on the biological properties of mountain soils of the Northwest Caucasus region  

NASA Astrophysics Data System (ADS)

The biological activity of different subtypes of soddy-calcareous soils (rendzinas) of the Northwest Caucasus region was studied. In the Novorossiisk-Abrau-Dyurso region (dry subtropics), typical soddy-calcareous soils with the high content of carbonates predominate; in the more humid conditions of the Lagonaki Plateau (Republic of Adygeya), leached soddy-calcareous soils carbonate-free down to the parent rock are spread. The number of microarthropods, the populations of fungi and bacteria, and the enzyme activity (catalase, dehydrogenase, and invertase) testify that the biological activity of these soils significantly differs. In the typical soddy-calcareous soils of the dry subtropics, the content of carbonates does not affect the characteristics mentioned; in the more humid conditions of the West Caucasus region, the presence of carbonates in the parent rocks intensifies the biological activity of the soddy-calcareous soils.

Kazeev, K. Sh.; Kutrovskii, M. A.; Dadenko, E. V.; Vezdeneeva, L. S.; Kolesnikov, S. I.; Val'kov, V. F.

2012-03-01

83

Soil enzymatic activity and growth of rice and barley as influenced by organic manure in an anthropogenic soil  

Microsoft Academic Search

Pot experiments were conducted with rice and barley to investigate the influence of incorporated organic manure in an anthropogenic (paddy) soil on the enzymatic and biological activities and on the growth and mineral composition of plants. The soil used for the experiments was sampled in the coastal zone of eastern Jiangsu Province, China. The soil was an anthropogenic derived from

Yongchao Liang; Yanfang Yang; Chaoguang Yang; Qirong Shen; Jianmin Zhou; Linzhang Yang

2003-01-01

84

Effect of deforestation on soil microbial activity  

Microsoft Academic Search

All crops grow in the soil environment; thus, soil properties are of great importance to determine plant and crop conditions. An index to assess soil fertility is its microbial activity. In this sense, in the present work we report the microbial activity of three soils selected by age of deforestation as determined by microcalorimetry at 25°C and its correlation with

E. Elizabeth Sigstad; Maricel A Bejas; M Julia Amoroso; Celina I Garc??a

2002-01-01

85

Effects of Cd and Pb on soil microbial community structure and activities  

Microsoft Academic Search

Background, aim, and scope  Soil contamination with heavy metals occurs as a result of both anthropogenic and natural activities. Heavy metals could have\\u000a long-term hazardous impacts on the health of soil ecosystems and adverse influences on soil biological processes. Soil enzymatic\\u000a activities are recognized as sensors towards any natural and anthropogenic disturbance occurring in the soil ecosystem. Similarly,\\u000a microbial biomass carbon

Sardar Khan; Abd El-Latif Hesham; Min Qiao; Shafiqur Rehman; Ji-Zheng He

2010-01-01

86

Diversity and Activity of Denitrifiers of Chilean Arid Soil Ecosystems  

PubMed Central

The Chilean sclerophyllous matorral is a Mediterranean semiarid ecosystem affected by erosion, with low soil fertility, and limited by nitrogen. However, limitation of resources is even more severe for desert soils such as from the Atacama Desert, one of the most extreme arid deserts on Earth. Topsoil organic matter, nitrogen and moisture content were significantly higher in the semiarid soil compared to the desert soil. Although the most significant loss of biologically preferred nitrogen from terrestrial ecosystems occurs via denitrification, virtually nothing is known on the activity and composition of denitrifier communities thriving in arid soils. In this study we explored denitrifier communities from two soils with profoundly distinct edaphic factors. While denitrification activity in the desert soil was below detection limit, the semiarid soil sustained denitrification activity. To elucidate the genetic potential of the soils to sustain denitrification processes we performed community analysis of denitrifiers based on nitrite reductase (nirK and nirS) genes as functional marker genes for this physiological group. Presence of nirK-type denitrifiers in both soils was demonstrated but failure to amplify nirS from the desert soil suggests very low abundance of nirS-type denitrifiers shedding light on the lack of denitrification activity. Phylogenetic analysis showed a very low diversity of nirK with only three distinct genotypes in the desert soil which conditions presumably exert a high selection pressure. While nirK diversity was also limited to only few, albeit distinct genotypes, the semiarid matorral soil showed a surprisingly broad genetic variability of the nirS gene. The Chilean matorral is a shrub land plant community which form vegetational patches stabilizing the soil and increasing its nitrogen and carbon content. These islands of fertility may sustain the development and activity of the overall microbial community and of denitrifiers in particular. PMID:22493591

Orlando, Julieta; Caru, Margarita; Pommerenke, Bianca; Braker, Gesche

2012-01-01

87

Assessment of soil tolerance toward contamination with black oil in the south of Russia on the basis of soil biological indices: A model experiment  

NASA Astrophysics Data System (ADS)

The effect of soil contamination with black oil added in amounts of 0.1, 0.5, 1.0, 2.5, 5, 10, 25, and 50% of the soil mass on the biological properties of ordinary and leached vertic chernozems, brown forest soils, and gray sands in the south of Russia was studied in a model laboratory experiment. It was shown that the soil contamination causes a drop in the catalase and dehydrogenase activities, the cellulolytic capacity, the number of Azotobacter bacteria, and the characteristics of the plant germination. The ordinary and vertic chernozems were more tolerant toward the contamination than the gray sands and brown forest soils. The changes in the biological soil properties in dependence on the degree of the soil contamination differed considerably for the soils with different properties (the chernozems, brown forest soil, and gray sands) and were similar for the soils with similar properties (the ordinary and vertic chernozems). One soil (the brown forest soil) could be more tolerant toward the contamination than another soil (the gray sands) at a given concentration of black oil (<2.5%) and less tolerant at another concentration of black oil (>2.5%). The ecologically safe levels of the soil contamination with black oil do not exceed 0.7% in the ordinary chernozems, 0.3% in the compact chernozems, 0.1% in the brown forest soils, and 0.06% in the gray sands.

Kolesnikov, S. I.; Gaivoronskii, V. G.; Rotina, E. N.; Kazeev, K. Sh.; Val'Kov, V. F.

2010-08-01

88

Microorganisms of Biological Crusts on Soil Surfaces  

Microsoft Academic Search

Our knowledge of the biodiversity of soil crust biota from different geographical regions is rather dissimilar. This, on the one hand, is based on different methods applied by most floristic studies (e.g., determination is only rarely based on cultured material in the case of cyanobacteria, algae and fungi). On the other hand, the species concept, especially of cyanobacteria, is currently

Burkhard Büdel

89

Biological Soil Crusts and Ecosystem Nitrogen and Carbon Dynamics  

Microsoft Academic Search

\\u000a Biological soil crusts are found in diverse ecosystems. They reach their best development in deserts and polar\\/alpine regions\\u000a where harsh environments limit growth by higher plants allowing the ground surface to be exposed to direct sunlight (see Chap.\\u000a 1). Coverage of soil crusts in these ecosystems can approach 100% in plant interspaces and total coverage may exceed that\\u000a of higher

R. D. Evans; O. L. Lange

90

REGULAR ARTICLE Impact of biological soil crusts and desert plants on soil  

E-print Network

REGULAR ARTICLE Impact of biological soil crusts and desert plants on soil microfaunal community are supplied by a variety of sources in the desert food web; both vascular and non-vascular plants and cyanobacteria supply carbon, and cyanobacteria and plant-associated rhizosphere bacteria are sources

Neher, Deborah A.

91

Untangling the biological contributions to soil stability in semiarid shrublands  

USGS Publications Warehouse

Communities of plants, biological soil crusts (BSCs), and arbuscular mycorrhizal (AM) fungi are known to influence soil stability individually, but their relative contributions, interactions, and combined effects are not well understood, particularly in arid and semiarid ecosystems. In a landscape-scale field study we quantified plant, BSC, and AM fungal communities at 216 locations along a gradient of soil stability levels in southern Utah, USA. We used multivariate modeling to examine the relative influences of plants, BSCs, and AM fungi on surface and subsurface stability in a semiarid shrubland landscape. Models were found to be congruent with the data and explained 35% of the variation in surface stability and 54% of the variation in subsurface stability. The results support several tentative conclusions. While BSCs, plants, and AM fungi all contribute to surface stability, only plants and AM fungi contribute to subsurface stability. In both surface and subsurface models, the strongest contributions to soil stability are made by biological components of the system. Biological soil crust cover was found to have the strongest direct effect on surface soil stability (0.60; controlling for other factors). Surprisingly, AM fungi appeared to influence surface soil stability (0.37), even though they are not generally considered to exist in the top few millimeters of the soil. In the subsurface model, plant cover appeared to have the strongest direct influence on soil stability (0.42); in both models, results indicate that plant cover influences soil stability both directly (controlling for other factors) and indirectly through influences on other organisms. Soil organic matter was not found to have a direct contribution to surface or subsurface stability in this system. The relative influence of AM fungi on soil stability in these semiarid shrublands was similar to that reported for a mesic tallgrass prairie. Estimates of effects that BSCs, plants, and AM fungi have on soil stability in these models are used to suggest the relative amounts of resources that erosion control practitioners should devote to promoting these communities. This study highlights the need for system approaches in combating erosion, soil degradation, and arid-land desertification.

Chaudhary, V. Bala; Bowker, Matthew A.; O'Dell, Thomas E.; Grace, James B.; Redman, Andrea E.; Rillig, Matthias C.; Johnson, Nancy C.

2009-01-01

92

Biological and abiotic losses of polynuclear aromatic hydrocarbons (PAHs) from soils freshly amended with sewage sludge  

SciTech Connect

Sewage sludge containing typical indigenous concentrations of polynuclear aromatic hydrocarbons (PAHs) was applied to several different soils in glass microcosms. Biologically active and sterilized soils were monitored for PAH content over a period of approximately 205 d. Agricultural soils with and without previous exposure to sewage sludge were tested, together with a forest soil and a soil from a major roadside. Loss of PAHs from a soil spike with a PAH standard solution was also investigated. Results indicate the PAH compounds with less than four benzene rings are susceptible to abiotic loss processes. However, losses by these mechanisms were insignificant for compounds with four or more benzene rings. Half-lives for the sludge-applied PAHs were derived and indicated a strong dependence of persistence on chemical structure. Half-lives for phenanthrene and benzo[ghi]perylene were between 83 and 193 d and 282 and 535 d, respectively. Mean half-lives correlate directly with log K[sub ow] and inversely with log water solubility. Behavior of PAHs was different in each soil, probably due to different soil characteristics and history of PAH exposure. The soil spiked with PAHs provided the lowest half-life values for most PAH compounds, suggesting a higher susceptibility of spiked PAHs to both abiotic and biological degradation.

Wild, S.R.; Jones, K.C. (Lancaster Univ. (United Kingdom))

1993-01-01

93

Short-term effects of different organic amendments on soil chemical, biochemical and biological indicators  

NASA Astrophysics Data System (ADS)

The limited availability of animal manure and the high cost of good quality compost lead to difficult soil quality management under organic agriculture. Therefore, it is important to find out alternative organic soil amendments and more flexible strategies that are able to sustain crop productivity and maintain and enhance soil quality. A three years study was carried out in the experimental fields of the Mediterranean Agronomic Institute of Bari located in Valenzano, Italy. The main objective of this research is to investigate the effects of different fertility management strategies on soil quality in order to estimate the role of innovative matrices for their use in organic farming. The experiment consists of seven treatments applied to a common crop rotation. The treatments include alternative organic amendments (1- olive mill wastewater OMW, 2- residues of mushroom cultivation MUS, 3- coffee chaff COF), common soil amendments (4- compost COM, 5- faba bean intercropping LEG, 6- cow manure - MAN) and as a reference treatment (7- mineral fertilizer COV). The soil quality was assessed before and after the application of the treatments, through biological (microbial biomass carbon and nitrogen, soil respiration and metabolic quotient), biochemical (soil enzymatic activities: ?-glucosidase, alkaline phospatase, urease, fluorescein diacetate (FDA) hydrolysis), and chemical (pH, soil organic carbon, soil organic matter, total nitrogen, available phosphorous, exchangeable potassium, dissolved organic carbon and total dissolved nitrogen) indicators. Based on the results obtained after the second year, all treatments were able to improve various soil chemical parameters as compared to mineral fertilizer. The incorporation of COF and OMW seemed to be more effective in improving soil total N and exchangeable K, while MAN significantly increased available P. All the amendments enhance dissolved organic C, soil respiration, microbial biomass and metabolic quotient as compared to control soil. Results concerning biochemical indicators revealed that phosphatase and ?-glycosidase were significantly reduced, while activities of urease and FDA were improved in all amended plots in comparison to the control, regardless of amendment type. Data demonstrated the efficiency, the high sensitivity and a quick response of the biochemical indicators in assessing soil quality changes. As a conclusion, it is possible to emphasize that alternative and common soil organic amendments behave similarly in enhancing the chemical, biochemical and biological properties. The alternative soil organic amendments could, then, be candidates for substituting some commonly used one which are currently showing shortage in their supply and a lowering in their quality. Keywords: Organic agriculture, Soil quality, Enzymatic activities, Olive mill wastewater, Residues of mushroom cultivation, Coffee chaff.

Mondelli, Donato; Aly, Adel; Yirga Dagnachew, Ababu; Piscitelli, Lea; Dumontet, Stefano; Miano, Teodoro

2014-05-01

94

Relevance of ammonium oxidation within biological soil crust communities  

USGS Publications Warehouse

Thin, vertically structured topsoil communities that become ecologically important in arid regions (biological soil crusts or BSCs) are responsible for much of the nitrogen inputs into pristine arid lands. We studied N2 fixation and ammonium oxidation (AO) at subcentimetre resolution within BSCs from the Colorado Plateau. Pools of dissolved porewater nitrate/ nitrite, ammonium and organic nitrogen in wetted BSCs were high in comparison with those typical of aridosoils. They remained stable during incubations, indicating that input and output processes were of similar magnitude. Areal N2 fixation rates (6.5-48 ??mol C2H2 m-2 h -1) were high, the vertical distribution of N2 fixation peaking close to the surface if populations of heterocystous cyanobacteria were present, but in the subsurface if they were absent. Areal AO rates (19-46 ??mol N m-2 h-1) were commensurate with N2 fixation inputs. When considering oxygen availability, AO activity invariably peaked 2-3 mm deep and was limited by oxygen (not ammonium) supply. Most probable number (MPN)-enumerated ammonia-oxidizing bacteria (6.7-7.9 ?? 103 cells g-1 on average) clearly peaked at 2-3 mm depth. Thus, AO (hence nitrification) is a spatially restricted but important process in the nitrogen cycling of BSC, turning much of the biologically fixed nitrogen into oxidized forms, the fate of which remains to be determined.

Johnson, S.L.; Budinoff, C.R.; Belnap, J.; Garcia-Pichel, F.

2005-01-01

95

Cropping Systems Management, Soil Microbial Communities, and Soil Biological Fertility  

Microsoft Academic Search

\\u000a Consumers are demanding more organic products, in part because of concerns over environmental issues in conventional agriculture.\\u000a Modern, high-input agriculture can cause groundwater contamination, soil erosion, and eutrophication of surface waters. It\\u000a may be possible to enhance natural nutrient cycling and reduce our dependence on inorganic fertilizers in cropping systems.\\u000a To do so, we have to manage our cropping systems

Alison G. Nelson; Dean Spaner

96

Soil Biology & Biochemistry 39 (2007) 22502263 Dynamics of labile and recalcitrant soil carbon pools in a sorghum  

E-print Network

-adequate (wet) and water-deficient (dry) treatments. We found that on average 53% of the final soil organic for the upper soil horizon (0­30 cm) where new carbon in recalcitrant soil pools of FACE wet and dry treatmentsSoil Biology & Biochemistry 39 (2007) 2250­2263 Dynamics of labile and recalcitrant soil carbon

Williams, David G.

97

The role of biological soil crusts in soil moisture dynamics in two semiarid ecosystems with contrasting soil textures  

NASA Astrophysics Data System (ADS)

The interplant soil surfaces in most arid and semiarid ecosystems are covered by biological soil crusts (BSCs). These crusts regulate water inputs and losses through soils and play major roles in local hydrological regimes. In recent years, the role of BSCs in infiltration and runoff has gained increasing importance and better knowledge of their effects on these processes has been acquired. However, the role of BSCs in other important components of the water balance, such as evaporation or soil moisture has hardly been studied, so their effects on these processes remain unknown. The aim of this study was to explore the influence of BSCs on soil moisture regimes in the top layer of the soil in two semiarid ecosystems in SE Spain with different particle-size distributions. At both study sites, soil moisture was monitored at 0.03 and 0.10 m under two types of BSCs, a cyanobacteria-dominated BSC and a lichen-dominated BSC, and in adjacent soils where they had been removed. Our results showed that during wet soil periods, removal of BSCs led to decreased soil moisture, especially in the upper layer (0.03 m), compared to soils covered by BSCs. Decrease in soil moisture was more noticeable after removal of lichens than cyanobacterial BSCs, and more so in fine than in coarse-textured soils. Soil water loss was also generally faster in soils with no BSCs than in soils covered by them. However, no difference was found in soil moisture under either crusted or scalped soils during soil drying periods. The type of BSC influenced soil moisture differently depending on soil water content. During wet soil periods, soil water loss was faster and soil moisture lower under cyanobacterial than under lichen BSCs. On the contrary, during soil drying periods, soils covered by lichens lost water faster and showed lower moisture than those covered by cyanobacteria. Our results show the major role of the presence of BSCs, as well as the types, in soil water content in semiarid ecosystems.

Chamizo, Sonia; Cantón, Yolanda; Lázaro, Roberto; Domingo, Francisco

2013-05-01

98

Influence of Disturbance on Soil Respiration in Biologically Crusted Soil during the Dry Season  

PubMed Central

Soil respiration (Rs) is a major pathway for carbon cycling and is a complex process involving abiotic and biotic factors. Biological soil crusts (BSCs) are a key biotic component of desert ecosystems worldwide. In desert ecosystems, soils are protected from surface disturbance by BSCs, but it is unknown whether Rs is affected by disturbance of this crust layer. We measured Rs in three types of disturbed and undisturbed crusted soils (algae, lichen, and moss), as well as bare land from April to August, 2010, in Mu Us desert, northwest China. Rs was similar among undisturbed soils but increased significantly in disturbed moss and algae crusted soils. The variation of Rs in undisturbed and disturbed soil was related to soil bulk density. Disturbance also led to changes in soil organic carbon and fine particles contents, including declines of 60–70% in surface soil C and N, relative to predisturbance values. Once BSCs were disturbed, Q10 increased. Our findings indicate that a loss of BSCs cover will lead to greater soil C loss through respiration. Given these results, understanding the disturbance sensitivity impact on Rs could be helpful to modify soil management practices which promote carbon sequestration. PMID:24453845

Feng, Wei; Zhang, Yu-qing; Wu, Bin; Zha, Tian-shan; Jia, Xin; Qin, Shu-gao; Shao, Chen-xi; Liu, Jia-bin; Lai, Zong-rui; Fa, Ke-yu

2013-01-01

99

Biochar and biological carbon cycling in temperate soils  

NASA Astrophysics Data System (ADS)

Production of biochar, the recalcitrant residue formed by pyrolysis of plant matter, is suggested as a means of increasing storage of stable carbon (C) in the soil (1). Biochar has also been shown to act as a soil conditioner, increasing the productivity of certain crops by reducing nutrient leaching and improving soil water-holding capacity. However, the response of soil carbon pools to biochar addition is not yet well understood. Studies have shown that biochar has highly variable effects on microbial C cycling and thus on soil C storage (2,3,4). This discrepancy may be partially explained by the response of soil invertebrates, which occupy higher trophic levels and regulate microbial activity. This research aims to understand the role of soil invertebrates (i.e. Collembola and nematode worms) in biochar-mediated changes to soil C dynamics across a range of plant-soil communities. An open-air, pot-based mesocosm experiment was established in May, 2011 at the Centre for Ecology and Hydrology, Edinburgh. Three treatments were included in a fully-factorial design: biochar (presence [2 % w/w] or absence), soil type (arable sandy, arable sandy loam, grassland sandy loam), and vegetation type (Hordeum vulgare, Lolium perenne, unvegetated). Monitored parameters include: invertebrate and microbial species composition, soil C fluxes (CO2 and trace gas evolution, leachate C content, primary productivity and soil C content), and soil conditions (pH, moisture content and water-holding capacity). Preliminary results indicate that biochar-induced changes to soil invertebrate communities and processes are affected by pre-existing soil characteristics, and that soil texture in particular may be an important determinant of soil response to biochar addition. 1. Lehmann, 2007. A handful of carbon. Nature 447, 143-144. 2. Liang et al., 2010. Black carbon affects the cycling of non-black carbon in soil. Organic Geochemistry 41, 206-213. 3. Van Zwieten et al., 2010. Influence of biochars on flux of N2O and CO2 from Ferrosol. Australian Journal of Soil Research, 48, 555-568. 4. Wardle et al., 2008. Fire-derived charcoal causes loss of forest humus. Science 320, 629.

McCormack, S. A.; Vanbergen, A. J.; Bardgett, R. D.; Hopkins, D. W.; Ostle, N.

2012-04-01

100

Characterization of biochemical properties and biological activities of biosurfactants produced by Pseudomonas aeruginosa mucoid and non-mucoid strains isolated from hydrocarbon-contaminated soil samples  

Microsoft Academic Search

Biochemical and pharmacological properties of biosurfactants produced at 45°C temperature by Pseudomonas aeruginosa mucoid (M) and non-mucoid (NM) strains, isolated from hydrocarbon-contaminated soil samples, were characterized. Both the strains secreted appreciable amount of biosurfactants (5.0–6.5 g\\/l), responsible for the reduction of surface tension of the medium from 68 to 29±0.5 mN\\/m post 96 h of growth. Maximum yield of biosurfactants was observed following

Kishore Das; Ashis K. Mukherjee

2005-01-01

101

The Soil Moisture Active Passive (SMAP) Mission  

Microsoft Academic Search

The Soil Moisture Active Passive (SMAP) mission is one of the first Earth observation satellites being developed by NASA in response to the National Research Council's Decadal Survey. SMAP will make global measurements of the soil moisture present at the Earth's land surface and will distinguish frozen from thawed land surfaces. Direct observations of soil moisture and freeze\\/thaw state from

Dara Entekhabi; Eni G. Njoku; Peggy E. O'Neill; Kent H. Kellogg; Wade T. Crow; Wendy N. Edelstein; Jared K. Entin; Shawn D. Goodman; Thomas J. Jackson; Joel Johnson; John Kimball; Jeffrey R. Piepmeier; Randal D. Koster; Neil Martin; Kyle C. McDonald; Mahta Moghaddam; Susan Moran; Rolf Reichle; J. C. Shi; Michael W. Spencer; Samuel W. Thurman; Leung Tsang; Jakob Van Zyl

2010-01-01

102

NO gas loss from biologically crusted soils in Canyonlands National Park, Utah  

E-print Network

-1 NO gas loss from biologically crusted soils in Canyonlands National Park, Utah NICHOLE N. BARGER; accepted in revised form 28 January 2005 Key words: Biological soil crust, Canyonlands National Park gas loss as nitric oxide (NO) from N-fixing biologically crusted soils in Canyonlands National Park

Barger, Nichole

103

Growth and Nutrient Content of Herbaceous Seedlings Associated with Biological Soil Crusts  

Microsoft Academic Search

Biological soil crusts of arid and semiarid lands contribute significantly to ecosystem stability by means of soil stabilization, nitrogen fixation, and improved growth and establishment of vascular plant species. In this study, we examined growth and nutrient content of Bromus tectorum, Elymus elymoides, Gaillardia pulchella, and Sphaeralcea munroana grown in soil amended with one of three levels of biological soil

R. L. Pendleton; B. K. Pendleton; G. L. Howard; S. D. Warren

2003-01-01

104

Biological soil crust and surface soil properties in different vegetation types of Horqin Sand Land, China  

Microsoft Academic Search

Physical and chemical properties (including coverage, thickness, hardness, moisture, particle size distribution, organic matter and nutrient contents etc.) of biological soil crust and 0–5.0cm surface soil under the crust in three types of vegetation (semi-shrub Artemisia frigida, shrub Salix gordejevii and tree Populus simonii) were surveyed in 2005 and 2006 in Horqin Sand Land to understand the effects of different

Ha-Lin Zhao; Yi-Rui Guo; Rui-Lian Zhou; Sam Drake

2010-01-01

105

Functional Polymers with Biologically Active Groups  

Microsoft Academic Search

Synthetic polymers with functional groups, especially where the functional group is a biologically active group, are receiving considerable attention, since such polymeric drugs represent novel drug delivery systems. In this paper methods for the preparation of typical classes of polymers with biologically active groups were explored. As an example of a condensation polymer, primaquine was incorporated in a polymer chain

Otto Vogl; David Tirrell

1979-01-01

106

Milk Biologically Active Components as Nutraceuticals: Review  

Microsoft Academic Search

Milk contains components that provide critical nutritive elements, immunological protection, and biologically active substances to both neonates and adults. Milk proteins are currently the main source of a range of biologically active peptides. Concentrates of these peptides are potential health-enhancing nutraceuticals for food and pharmaceutical applications. Several bioactive peptides may be used as nutraceuticals, for example, in the treatment of

Sindayikengera Séverin; Xia Wenshui

2005-01-01

107

Warming and increased precipitation frequency on the Colorado Plateau: Implications for biological soil crusts and soil processes  

USGS Publications Warehouse

Taken together, our results highlight the limited effects of warming alone on biological soil crust communities and soil chemistry, but demonstrate the substantially larger effects of altered summertime precipitation.

Zelikova, Tamara J.; Housman, David C.; Grote, Ed E.; Neher, Deborah A.; Belnap, Jayne

2012-01-01

108

Ice Nucleation Activity in the Widespread Soil Fungus Mortierella alpina  

NASA Astrophysics Data System (ADS)

Biological residues in soil dust are a potentially strong source of atmospheric ice nuclei (IN). So far, however, the abundance, diversity, sources, seasonality, and role of biological - in particular, fungal - IN in soil dust have not been characterized. By analysis of the culturable fungi in topsoils, from a range of different land use and ecosystem types in south-east Wyoming, we found ice nucleation active (INA) fungi to be both widespread and abundant, particularly in soils with recent inputs of decomposable organic matter. Across all investigated soils, 8% of fungal isolates were INA. All INA isolates initiated freezing at -5 to -6 °C, and belonged to a single zygomycotic species, Mortierella alpina (Mortierellales, Mortierellomycotina). By contrast, the handful of fungal species so far reported as INA all belong within the Ascomycota or Basidiomycota phyla. M. alpina is known to be saprobic, widespread in soil and present in air and rain. Sequencing of the ITS region and the gene for ?-linolenic-elongase revealed four distinct clades, affiliated to different soil types. The IN produced by M. alpina seem to be proteinaceous, <300 kDa in size, and can be easily washed off the mycelium. Ice nucleating fungal mycelium will ramify topsoils and probably also release cell-free IN into it. If these IN survive decomposition or are adsorbed onto mineral surfaces, their contribution might accumulate over time, perhaps to be transported with soil dust and influencing its ice nucleating properties.

Fröhlich-Nowoisky, J.; Hill, T. C. J.; Pummer, B. G.; Franc, G. D.; Pöschl, U.

2014-08-01

109

Soil Biology & Biochemistry 38 (2006) 22922299 Modifications of degradation-resistant soil organic matter by soil  

E-print Network

an important factor in their transformations in arable soils. The enzyme involved in FA modifications frequent soil microfungal species. This can be one of the first but important step towards learning, terricolous basidiomycetes, ectomycorrhizal fungi, soil-borne micro- fungi and bacteria were found to be able

Miksik, Ivan

110

Active Transport in Biological Computing (Preliminary Version)  

E-print Network

have hamiltonian paths, indeed, the line digraphs are hamiltonian paths. v 0 e 0,1 v 1 e 1,2 v 2 e 2Active Transport in Biological Computing (Preliminary Version) Stuart A. Kurtz Stephen R. Mahaney James S. Royer Janos Simon May 24, 1996 Abstract Early papers on biological computing focussed

Royer, James S.

111

Minds-On Activities for Teaching Biology  

NSDL National Science Digital Library

These minds-on activities include discussion activities, web-based activities, experiments and simulation activities to foster student understanding of important concepts in the life sciences. Topics covered include biological molecules, membranes and osmosis, cellular respiration and photosynthesis, cell structure and function, cell division, genetics, molecular biology, evolution, diversity, human physiology and health, and design and interpretation of experiments. These activities were designed for teaching high school students, but many of them can also be used with middle school students or in non-major introductory college biology classes. Most of the hands-on experiments and simulation activities are described in student handouts and teacher notes; the student handouts are available as Word files for teachers to customize for their students. To accommodate limited budgets, most of the hands-on activities can be carried out with minimum equipment and expense for supplies.

2012-01-13

112

Size adjustable separation of biologically active molecules  

E-print Network

Separation of biologically active molecules (BAM's) is a problem for the pharmaceutical and biotechnology industries. Current technologies addressing this problem require too many techniques, toxic additives, and time to ...

Gutierrez, Mauricio R. (Mauricio Roberto)

2004-01-01

113

Large-scale experience with biological treatment of contaminated soil  

SciTech Connect

The efficiency of biological methods for the cleanup of soil contaminated with total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) was demonstrated by a large-scale example in which 38,000 tons of TPH- and PAH-polluted soil was treated onsite with the TERRAFERM{reg_sign} degradation system to reach the target values of 300 mg/kg TPH and 5 mg/kg PAH. Detection of the ecotoxicological potential (Microtox{reg_sign} assay) showed a significant decrease during the remediation. Low concentrations of PAH in the ground were treated by an in situ technology. The in situ treatment was combined with mechanical measures (slurry wall) to prevent the contamination from dispersing from the site.

Schulz-Berendt, V.; Poetzsch, E. [Umweltschutz Nord GmbH and Co., Ganderkesee (Germany)

1995-12-31

114

Soil biological attributes in arsenic-contaminated gold mining sites after revegetation.  

PubMed

Recovery of arsenic contaminated areas is a challenge society faces throughout the world. Revegetation associated with microbial activity can play an essential role in this process. This work investigated biological attributes in a gold mining area with different arsenic contents at different sites under two types of extant revegetation associated with cover layers of the soil: BS, Brachiaria sp. and Stizolobium sp., and LEGS, Acacia crassicarpa, A. holosericea, A. mangium, Sesbania virgata, Albizia lebbeck and Pseudosamanea guachapele. References were also evaluated, comprising the following three sites: B1, weathered sulfide substrate without revegetation; BM, barren material after gold extraction and PRNH (private reserve of natural heritage), an uncontaminated forest site near the mining area. The organic and microbial biomass carbon contents and substrate-induced respiration rates for these sites from highest to lowest were: PRNH > LEGS > BS > B1 and BM. These attributes were negatively correlated with soluble and total arsenic concentration in the soil. The sites that have undergone revegetation (LEGS and BS) had higher densities of bacteria, fungi, phosphate solubilizers and ammonium oxidizers than the sites without vegetation. Principal component analysis showed that the LEGS site grouped with PRNH, indicating that the use of leguminous species associated with an uncontaminated soil cover layer contributed to the improvement of the biological attributes. With the exception of acid phosphatase, all the biological attributes were indicators of soil recovery, particularly the following: microbial carbon, substrate-induced respiration, density of culturable bacteria, fungi and actinobacteria, phosphate solubilizers and metabolic quotient. PMID:24114185

Dos Santos, Jessé Valentim; de Melo Rangel, Wesley; Azarias Guimarăes, Amanda; Duque Jaramillo, Paula Marcela; Rufini, Márcia; Marra, Leandro Marciano; Varón López, Maryeimy; Pereira da Silva, Michele Aparecida; Fonsęca Sousa Soares, Cláudio Roberto; de Souza Moreira, Fatima Maria

2013-12-01

115

Methanogenic activities in alpine soils.  

PubMed

Uncontrolled microbial methane production is playing an important role in global warming. In the present study, we showed that water content and incubation temperature increase the potential for methane formation in the two alpine soils under investigation. Beside these factors, the grazing of cows and thus the amendment of methanogenic microorganisms by cattle dung is the most important factor determining the potential of methane production in those soils. PMID:22528315

Wagner, Andreas O; Hofmann, Katrin; Prem, Eva; Illmer, Paul

2012-07-01

116

Physical and biological soil attributes due to soil management on sugarcane  

NASA Astrophysics Data System (ADS)

The use of different crops can improve the physical and biological soil attributes, reducing soil and environmental degradation. The objective of this study was to evaluate the effect of different land uses on the glomalin fractions, total external mycelium and soil aggregation. The experiment was carried out in Brazil (21°14'05'' S and 48°17'09'' W) in eutroferric Red Oxisol (clay content = 700 g kg-1) and acric Oxisol (clay content = 450 g kg-1). The soil was submitted to two soybean growing seasons, with different crops (millet and sunnhemp) between them, during two sugarcane growth interval periods. The experimental design was a randomized block with five replications and four treatments, characterized by different land uses during the interval between two sugarcane growth periods. The land uses were the crops of: soybean, soybean/millet/soybean, soybean/sunnhemp/soybean and soybean/fallow/soybean. Soil samples were taken at the 0 - 0.10 m depth after the first sugarcane harvest. On both soils the glomalin fractions were not influenced by the different land uses. On the eutroferric Red Oxisol, the use soybean/millet/soybean promoted the higher amount of total external mycelium and on the acric Oxisol soybean/fallow/soybean promoted the lower amount. The aggregate stability indexes on both soils types were not affected by the land uses. On the eutroferric Red Oxisol, the aggregate mean weight diameter was not influenced by the different land uses, but on the acric Oxisol, the uses soybean and soybean/millet/soybean promoted the higher values. The results indicated that the effects of plants on amount of total external mycelium and aggregate mean weight diameter of Oxisol are different depend upon the soil texture and soil fertility.

Fernandes, Carolina; Viviane Truber, Priscila; Corá, José Eduardo

2013-04-01

117

Soil nematode communities are ecologically more mature beneath late-than early-successional stage biological soil crusts  

E-print Network

Soil nematode communities are ecologically more mature beneath late- than early-successional stage-living soil nematode communities reflect their environment and have been used as biological indicators of soil condition. In this study, we test the hypothesis that nematode communities are successionally more mature

Neher, Deborah A.

118

N-CPMAS nuclear magnetic resonance spectroscopy and biological stability of soil organic nitrogen in whole soil and  

E-print Network

15 N-CPMAS nuclear magnetic resonance spectroscopy and biological stability of soil organic in the field. # 2003 Elsevier Ltd. All rights reserved. 1. Introduction The chemical structure of soil organic­NMR) and pyrolysis-mass spec- trometry (PyMS) to gain further information about the chemical structure of soil

Weliky, David

119

Stabilization of labile organic C along a chronosequence of soil development: mineralogical vs. biological controls  

NASA Astrophysics Data System (ADS)

Soil organic matter (SOM) represents an important reservoir for carbon (C), nitrogen (N), and other essential nutrients. Consequently, variation in SOM turnover rates regulates resource availability for soil microbial activity and plant growth. Long-term SOM stabilization generally involves restricted microbial access to SOM through a variety of processes including complexation with soil minerals. These organo-mineral interactions are influenced by mineral composition and texture, often related to soil age. Soil microorganisms also influence the stabilization of C inputs to the pedosphere through the production of refractory residues controlled in part by C allocation patterns during metabolism. In this study we examined, simultaneously, the contribution of these two C stabilizing mechanisms by ‘tracing’ the fate of two 13C-labeled substrates (glucose and p-hydroxybenzoic acid) along a 1600Kya chronosequence of soil development along the Cowlitz River in southwest Washington. Our objective was to evaluate the relationship between mineralogical and biological controls over C sequestration in soils. Mineralogical analyses were done using the selective dissolutions ammonium oxalate (AOD), and dithionite-citrate extraction (CBD). In this cool, humid environment, intermediate aged soils derived from the late Wisconsin Evans Creek drift (24ka) had the highest AOD extractable Al, Fe, and Si, indicating a higher concentration of poorly crystalline minerals relative to other terraces. Correspondingly, CBD extractable Fe increases with soil age, further supporting the idea that crystalline iron oxides are also more prevalent with weathering. Turnover of both 13C-labeled substrates was rapid (< 12.5 hrs) However, the proportion of substrate mineralized to CO2 varied among terraces. Mineralization to CO2 was significantly lower at 24ka than that for the other three age classes (0.25k, 220k, and 1,600k years bp), corresponding to higher recovery of 13C in bulk soil for this age class. In similar studies, soils containing a higher proportion of poorly crystalline minerals typically have a higher degree of hydration, surface area, and variable charge, which can increase microbial yield, reducing the amount of CO2 produced per unit biomass and increasing potential for soil C sequestration. Additionally, total flux of 13CO2 was significantly higher and recovery of 13C in microbial pools trended lower for the phenolic than for glucose for all soils types excluding the 24ka terrace. The broader implication, which may warrant consideration in models of terrestrial C flux, is that altering the constituency of labile C inputs to these soil environments could similarly influence the degree to which C is stabilized in soil mineral assemblages.

McFarland, J. W.; Waldrop, M. P.; Strawn, D.; Harden, J. W.

2010-12-01

120

Atmospheric CO2 and soil extracellular enzyme activity: a meta-analysis and CO2 gradient experiment  

E-print Network

N limitation with increasing CO2. In the sandy loam soil, alkaline phosphatase activity increasedAtmospheric CO2 and soil extracellular enzyme activity: a meta-analysis and CO2 gradient experiment Department of Biology, Duke University, Durham, North Carolina 27708 USA 2 Grassland, Soil & Water Research

Jackson, Robert B.

121

Biological activity of Glechoma hederacea.  

PubMed

The n-hexane, dichloromethane and methanol extracts of the aerial parts of Glechoma hederacea have been screened for antibacterial and free radical scavenging activity. General toxicity (brine shrimp lethality assay) of these extracts has also been assessed. PMID:12490241

Kumarasamy, Y; Cox, P J; Jaspars, M; Nahar, L; Sarker, S D

2002-12-01

122

Biological activity of Glechoma hederacea  

Microsoft Academic Search

The n-hexane, dichloromethane and methanol extracts of the aerial parts of Glechoma hederacea have been screened for antibacterial and free radical scavenging activity. General toxicity (brine shrimp lethality assay) of these extracts has also been assessed.

Y Kumarasamy; P. J Cox; M Jaspars; L Nahar; S. D Sarker

2002-01-01

123

Fractal Scaling of Particle Size Distribution and Relationships with Topsoil Properties Affected by Biological Soil Crusts  

PubMed Central

Background Biological soil crusts are common components of desert ecosystem; they cover ground surface and interact with topsoil that contribute to desertification control and degraded land restoration in arid and semiarid regions. Methodology/Principal Findings To distinguish the changes in topsoil affected by biological soil crusts, we compared topsoil properties across three types of successional biological soil crusts (algae, lichens, and mosses crust), as well as the referenced sandland in the Mu Us Desert, Northern China. Relationships between fractal dimensions of soil particle size distribution and selected soil properties were discussed as well. The results indicated that biological soil crusts had significant positive effects on soil physical structure (P<0.05); and soil organic carbon and nutrients showed an upward trend across the successional stages of biological soil crusts. Fractal dimensions ranged from 2.1477 to 2.3032, and significantly linear correlated with selected soil properties (R2?=?0.494?0.955, P<0.01). Conclusions/Significance Biological soil crusts cause an important increase in soil fertility, and are beneficial to sand fixation, although the process is rather slow. Fractal dimension proves to be a sensitive and useful index for quantifying changes in soil properties that additionally implies desertification. This study will be essential to provide a firm basis for future policy-making on optimal solutions regarding desertification control and assessment, as well as degraded ecosystem restoration in arid and semiarid regions. PMID:24516668

Gao, Guang-Lei; Ding, Guo-Dong; Wu, Bin; Zhang, Yu-Qing; Qin, Shu-Gao; Zhao, Yuan-Yuan; Bao, Yan-Feng; Liu, Yun-Dong; Wan, Li; Deng, Ji-Feng

2014-01-01

124

The Soil Moisture Active Passive (SMAP) Mission  

E-print Network

The Soil Moisture Active Passive (SMAP) mission is one of the first Earth observation satellites being developed by NASA in response to the National Research Council's Decadal Survey. SMAP will make global measurements of ...

Entekhabi, Dara

125

Assessing level of development and successional stages in biological soil crusts with biological indicators.  

PubMed

Biological soil crusts (BSCs) perform vital ecosystem services, but the difference in biological components or developmental level still affects the rate and type of these services. In order to differentiate crust successional stages in quantity and analyze the relationship between crust developmental level and successional stages, this work determined several biological indicators in a series of different developmental BSCs in the Shapotou region of China. The results showed that crust developmental level (level of development index) can be well indicated by crust biological indicators. Photosynthetic biomass was the most appropriate to differentiate crust successional stages, although both photosynthetic biomass and respiration intensity increased with the development and succession of BSCs. Based on of the different biological compositions, BSCs were quantificationally categorized into different successional stages including cyanobacterial crusts (lichen and moss coverages <20 %), lichen crusts (lichen coverage >20 % but moss coverage <20 %), semi-moss crusts (moss coverage >20 % but <75 %), and moss crusts (moss coverage >75 %). In addition, it was found that cyanobacterial and microalgal biomass first increased as cyanobacterial crusts formed, then decreased when lots of mosses emerged on the crust surface; however nitrogen-fixing cyanobacteria and heterotrophic microbes increased in the later developmental BSCs. The structural adjustment of biological components in the different developmental BSCs may reflect the requirement of crust survival and material transition. PMID:23389251

Lan, Shubin; Wu, Li; Zhang, Delu; Hu, Chunxiang

2013-08-01

126

Biological soil crusts: a fundamental organizing agent in global drylands  

NASA Astrophysics Data System (ADS)

Ecosystem function is profoundly affected by plant community composition, which is ultimately determined by factors that govern seed retention. Dryland ecosystems constitute ~35% of terrestrial surfaces, with most soils in these regions covered by biological soil crusts (biocrusts), a community whose autotrophs are dominated by cyanobacteria, lichens, and mosses. Studies at 550 sites revealed that plant community composition was controlled by the interaction among biocrust type, disturbance regime, and external morphology of seeds. In bare soils (due to disturbance), all seed types were present in the seedbank and plant community. As biocrusts became better developed (i.e., the cover of lichens and mosses increased), they more strongly filtered out seeds with appendages. Thus, soils under late successional biocrusts contained seedbanks dominated by smooth seeds and vascular plants growing in late successional biocrusts were dominated by those with smooth seeds. Therefore, the tension between the removal of biocrusts by soil surface disturbance and their recovery creates a shifting mosaic of plant patch types in both space and time. Because changes in vascular plant communities reverberate throughout both below ground and above ground food webs and thus affect multiple trophic levels, we propose that biocrusts are a fundamental organizing agent in drylands worldwide. Future increased demand for resources will intensify land use both temporally and spatially, resulting in an increased rate of biocrust loss across larger areas. As a result, we can expect shifts in the composition and distribution of plant communities, accompanied by concomitant changes in many aspects of dryland ecosystems. Conceptual model of shifting dryland plant mosaics through space and time. Within the large circles, soil surface type changes with time in the same space, going from bare uncrusted soil (B) to cyanobacterial biocrust (C) to lichen/moss (L/M) biocrust. Disturbance (D) drives the cycle back towards U, and recovery (R) drives it towards L/M. Larger disturbances and dispersal of biocrust organisms among the larger circles result in mosaics that shift in space as well. The bar chart shows the proportion of smooth (left side) and rough (right side) seeds under different crust types.

Belnap, J.; Zhang, Y.

2013-12-01

127

Rain pulse response of soil CO2 exchange by biological soil crusts and grasslands of the semiarid Colorado Plateau, United States  

USGS Publications Warehouse

Biological activity in arid grasslands is strongly dependent on moisture. We examined gas exchange of biological soil crusts (biocrusts), the underlying soil biotic community, and the belowground respiratory activity of C3 and C4 grasses over 2 years in southeast Utah, USA. We used soil surface CO2 flux and the amount and carbon isotope composition (?13C) of soil CO2 as indicators of belowground and soil surface activity. Soil respiration was always below 2 ?mol m-2s-1 and highly responsive to soil moisture. When moisture was available, warm spring and summer temperature was associated with higher fluxes. Moisture pulses led to enhanced soil respiration lasting for a week or more. Biological response to rain was not simply dependent on the amount of rain, but also depended on antecedent conditions (prior moisture pulses). The short-term temperature sensitivity of respiration was very dynamic, showing enhancement within 1-2 days of rain, and diminishing each day afterward. Carbon uptake occurred by cyanobacterially dominated biocrusts following moisture pulses in fall and winter, with a maximal net carbon uptake of 0.5 ?mol m-2s-1, although typically the biocrusts were a net carbon source. No difference was detected in the seasonal activity of C3 and C4 grasses, contrasting with studies from other arid regions (where warm- versus cool-season activity is important), and highlighting the unique biophysical environment of this cold desert. Contrary to other studies, the ?13C of belowground respiration in the rooting zone of each photosynthetic type did not reflect the ?13C of C3 and C4 physiology.

Bowling, D. R.; Grote, E. E.; Belnap, J.

2011-01-01

128

Biological soil crusts in subtropical China and their influence on initial soil erosion  

NASA Astrophysics Data System (ADS)

Soil is one of the most valuable resources we have on our planet. The erosion of this resource is a major environmental problem, in particular in subtropical China where high rainfall intensity causes severe and continuous soil losses. One of the main mechanisms controlling soil erosion is surface coverage, typically by vegetation, litter, stones and biological soil crusts (BSCs). BSCs play significant functional roles in soil systems, such as accelerating soil formation, changing water and nutrient cycling rates, enhancing soil stability and thus preventing erosion by wind or water. In initial ecosystems, cyanobacteria, algae, fungi, mosses and lichens are the first organisms to colonize the substrate; they form a biological crust within the first millimetres of the surface. BSCs and their effect on erosion are rarely mentioned in literature and most of the work done focussed on arid and semi-arid environments. This study aims to investigate the role of BSCs controlling the amount of runoff generated and sediment detached during soil erosion events in an initial ecosystem in subtropical China. The study took place on a deforested experimental site (BEF China) near Xingangshan, Jiangxi Province, PR China. We used a total number of 350 runoff plots (ROP, 40cmx40cm) to measure sediment discharge and surface runoff. BSC cover in each ROP was determined photogrammetrically in 4 time steps (autumn 2011, spring 2012, summer 2012 and summer 2013). Perpendicular images were taken and then processed to measure the coverage of BSCs using a 1 cm˛ digital grid overlay. Additionally BSCs were sampled in the field and identified by their taxonomy. In our ROPs we found 65 different moos, algae and lichen species, as well as cyanobacteria's. Mean BSC cover per ROP in 2013 was 17 % with a maximum of 62 % and a minimum of 0 %. Compared to stone cover with 3 %, our findings highlight the role of BSC in soil erosion processes. The total BSC covered area is slightly decreasing since our first measurements in 2011. Further results show that BSCs have an influence on sediment discharge and runoff volume and there is a considerable link to tree and shrub growth in our sampling area. BSCs disappear as trees and shrubs grow and hide them from sunlight.

Seitz, Steffen; Goebes, Philipp; Kühn, Peter; Scholten, Thomas

2014-05-01

129

[Chemistry and biological activities of Viburnum odoratissimum].  

PubMed

Viburnum odoratissimum is a folk medicinal plant, it can dredge the meridian passage and contains mainly diterpenes, triterpenes, flavonoids, sesquiterpenes, lignans, coumarin glycosides, etc. Vibsanin-type diterpenoids are the characteristic compounds of V. odoratissimum, and are divided into eleven-membered ring, seven-membered ring, and rearrangement-type. Vibsanin B, vibsanin C and neovibsanin A are the representative compounds of the three subtypes of vibsanin-type diterpenoids respectively. V. odoratissimum has cytotoxic activity, antibacterial activity, fish piscicidal activity and activity of inhibiting the growth of plants, Cytotoxic activity is the main biological activity. PMID:23724642

Liu, Jie; Zhou, Wen-Bin; Cong, Yu-Wen; Liu, Ping

2013-03-01

130

Perylenequinones: Isolation, Synthesis, and Biological Activity  

PubMed Central

The perylenequinones are a novel class of natural products characterized by pentacyclic conjugated chromophore giving rise to photoactivity. Potentially useful light-activated biological activity, targeting protein kinase C (PKC), has been identified for several of the natural products. Recently discovered new members of this class of compound, as well as several related phenanthroperylenequinones, are reviewed. Natural product modifications that improve biological profiles, and avenues for the total synthesis of analogs, which are not available from the natural product series, are outlined. An overview of structure/function relationships is provided. PMID:24039544

Mulrooey, Carol A.; O'Brien, Erin M.; Morgan, Barbara J.

2013-01-01

131

Soil acid and alkaline phosphatase activity as pH adjustment indicators  

Microsoft Academic Search

Soil fertility and crop production are affected by biological processes and these processes, including enzyme activites, are influenced by pH. We investigated the potential of using alkaline phosphatase (AlkP) and acid phosphatase (AcdP) activities, for determining the optimum soil pH for crop production and the amount of lime required to achieve this optimum. Five acid soils, which varied widely in

W. A. Dick; L. Cheng; P. Wang

2000-01-01

132

Influence of development stage and disturbance of physical and biological soil crusts on soil water erosion  

NASA Astrophysics Data System (ADS)

Most soils exposed to rainfall are prone to sealing and crusting processes causing physical soil crusts (PSCs). When climate and soil stability conditions are suitable, PSCs can be consolidated by a complex community consisting of cyanobacteria, bacteria, green algae, microfungi, lichens and bryophytes, which are collectively known as biological soil crust (BSC). The influence of soil crusts on erosion processes is complex: crusts may reduce detachment, increasing soil stability and protecting soil against raindrop impact, although that protection will depend on the type of soil crust and the stage of development; they can also build up runoff, suggesting that downstream erosion may actually be increased or favoured water harvesting to vegetated areas. On the other hand, BSCs have been demonstrated to be very vulnerable to disturbance which in turn can lead to accelerate soil erosion and other forms of land degradation. Incorporation of the response of different type of soil crusts and the effects of their disturbance is highly likely to improve the prediction of runoff and water erosion models in arid and semi-arid catchments. The objective of this work is to analyse the erosional response of PSCs and BSCs in different stages of their development and subject to distinct disturbances when extreme rainfalls intensities are applied at plot scale in semiarid environments. Small plots on the most representative crust types, corresponding to different stages of crust development, in two semiarid ecosystems in SE Spain, El Cautivo (in the Tabernas Desert) and Amoladeras (in the Natural Park Cabo de Gata-Níjar), were selected and three disturbance treatments were applied on each crust type: a) no disturbance (control), b) trampling, stepping 100 times over the crust and c) scraping. Two consecutive rainfall simulation experiments (50 mm/h rainfall intensity) were carried out on each plot: the first on dry soil and the second, 30 minutes later, on wet soil conditions. Samples of runoff were collected regularly during the rainfall simulation and sediments in runoff extracted later in laboratory. Erosion rates were significantly different at both sites, being lower in Amoladeras than in El Cautivo due to a flatter topography and a higher infiltration capacity of the sandy soils with higher organic matter content. There were not significant differences on total erosion rates between the first and the second rainfall event, as consequence of the increase of runoff under wet conditions. In El Cautivo, the erosion rates significantly decreased as crust development stage increased. However, in Amoladeras, the erosion was low in all crust types and there were not significant differences on erosion rates among the crust development stages. Among treatments, in El Cautivo, scraping and trampling promoted significant higher erosion rates than undisturbed crust, but no significant differences were found between both treatments, except for the lichen-dominated crust. In Amoladeras, no significant differences on erosion rates between the undisturbed and the trampled crust were found since in this area trampling did not have an important effect. Although the removal of the crust in semiarid environments, at local scale, always increased erosion, the effects of crust disturbance on erosion varied depending on the ecosystem, with stronger erosional effects in badland areas with a silty substrate and steep topography than in areas with a flat topography and a coarser soil texture.

Chamizo, S.; Cantón, Y.; Lázaro, R.; Solé-Benet, A.; Calvo-Cases, A.; Miralles, I.; Domingo, F.

2009-04-01

133

Biological activity of earthworm casts: An assessment of plant growth promotor levels in the casts  

Microsoft Academic Search

Biochemical analyses and auxin and cytokinin bioassays were performed to test the biological activity of wormcasts. Both cellulose\\u000a paper pulp and soil casts ofLampito mauritii were rich in ammonia, urea, organic carbon content, organic matter, soluble phosphorus and ionic potassium levels. The total\\u000a nitrogen content of the soil remained unaffected by worm activations. The casts ofLampito mauritii, Pheretima elongata, Pontoscolex

R V Krishnamoorthy; S N Vajranabhaiah

1986-01-01

134

Harnessing the Biological Activity of Natural Products  

Cancer.gov

Researchers have been intrigued by the potent and beneficial biological activity shown by some natural products and are testing ways to incorporate them into standard and experimental cancer treatment regimens, both to enhance the anticancer effects of therapy and reduce side effects.

135

Matrigel: Basement membrane matrix with biological activity  

Microsoft Academic Search

The basement membrane extracellular matrix contacts epithelial, endothelial, fat and smooth muscle cells. Because this extracellular matrix is so thin, it had been hard to study its composition, structure, and function. An extract of a tumor was found to contain all of the components present in basement and to be very biologically active. This extract, termed Matrigel, Cultrex, or EHS

Hynda K. Kleinman; George R. Martin

2005-01-01

136

The influence of biological soil crusts on mineral uptake by associated vascular plants  

Microsoft Academic Search

Soil surfaces dominated by cyanobacteria and cyanolichens (such as Collema sp.) are widespread in deserts of the world. The influence of these biological soil crusts on the uptake of bioessential elements is reported for the first time for six seed plants of the deserts of Utah. This sample almost doubles the number of species for which the influence of biological

Kimball T. Harper; Jayne BelnapK

2001-01-01

137

“In situ” vermicomposting of biological sludges and impacts on soil quality  

Microsoft Academic Search

A laboratory experiment was carried out to study soil quality amelioration through “in situ” vermicomposting of biological sludges. The experiment dealt with the stabilization, through the action of worms (Eisenia fetida), of five mixtures containing aerobic and anaerobic biological sludges spread on the soil surface. The results showed that by increasing the percentage of anaerobic sludge in the mixtures, the

G Masciandaro; B Ceccanti; C Garcia

2000-01-01

138

Impacts of biological soil crust disturbance and composition on C and N loss from water erosion  

E-print Network

Range, Las Cruces, NM 88003; 3 USGS ­ BRD Canyonlands Field Station, Moab, UT 84532; *Author 2005; accepted in revised form 27 July 2005 Key words: Biological soil crust, Carbon, Canyonlands on the role of biological soil crusts on surface hydrology and erosional dynamics, but associated nutrient

Barger, Nichole

139

Microarthropod communities associated with biological soil crusts in the Colorado Plateau and Chihuahuan deserts  

Microsoft Academic Search

Biological soil crusts provide habitat for microarthropods of various trophic groups in arid systems, but the community composition and functional role of microarthropods in these unique systems are not well characterized for many desert locations. This study examined the microarthropod community, including mites, collembolans, and tardigrades, associated with early- and late-successional stage biological soil crusts at two locations, Colorado Plateau

D. A. Neher; S. A. Lewins; T. R. Weicht; B. J. Darby

2009-01-01

140

Long-term effects of fertilizer on soil enzymatic activity of wheat field soil in Loess Plateau, China.  

PubMed

The effects of long-term (29 years) fertilization on local agro-ecosystems in the Loess Plateau of northwest China, containing a single or combinations of inorganic (Nitrogen, N; Phosphate, P) and organic (Mature, M Straw, S) fertilizer, including N, NP, SNP, M, MNP, and a control. The soil enzymes, including dehydrogenase, urease, alkaline phosphatase, invertase and glomalin, were investigated in three physiological stages (Jointing, Dough, and Maturity) of wheat growth at three depths of the soil profile (0-15, 16-30, 31-45 cm). We found that the application of farmyard manure and straw produced the highest values of soil enzymatic activity, especially a balanced applied treatment of MNP. Enzymatic activity was lowest in the control. Values were generally highest at dough, followed by the jointing and maturity stages, and declined with soil profile depth. The activities of the enzymes investigated here are significantly correlated with each other and are correlated with soil nutrients, in particular with soil organic carbon. Our results suggest that a balanced application of fertilizer nutrients and organic manure (especially those containing P) has positive effects on multiple soil chemical parameters, which in turn enhances enzyme activity. We emphasize the role of organic manure in maintaining soil organic matter and promoting biological activity, as its application can result in a substantial increase in agricultural production and can be sustainable for many years. PMID:25134679

Hu, Weigang; Jiao, Zhifang; Wu, Fasi; Liu, Yongjun; Dong, Maoxing; Ma, Xiaojun; Fan, Tinglu; An, Lizhe; Feng, Huyuan

2014-12-01

141

Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles  

PubMed Central

Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed. PMID:23015769

Kalinin, Vladimir I.; Ivanchina, Natalia V.; Krasokhin, Vladimir B.; Makarieva, Tatyana N.; Stonik, Valentin A.

2012-01-01

142

Short-Term Effect of Vermicompost Application on Biological Properties of an Alkaline Soil with High Lime Content from Mediterranean Region of Turkey  

PubMed Central

This study was conducted to investigate direct short-term impact of vermicompost on some soil biological properties by monitoring changes after addition of vermicompost as compared to farmyard manure in an alkaline soil with high lime content from semiarid Mediterranean region of Turkey. For this purpose, mixtures of soil and organic fertilizers in different doses were incubated under greenhouse condition. Soil samples collected in regular intervals were analyzed for biological parameters including dehydrogenase, ?-glucosidase, urease, alkaline phosphatase activities, and total number of aerobic mesophilic bacteria. Even though soil dehydrogenase activity appeared to be dose-independent based on overall evaluation, organic amendments were found to elevate dehydrogenase activity when sampling periods are evaluated individually. ?-glucosidase, urease, alkaline phosphatase activity, and aerobic mesophilic bacterial numbers in vermicompost treatments fluctuated but remained significantly above the control. A slight but statistically significant difference was detected between organic amendments in terms of urease activity. Vermicompost appeared to more significantly increase bacterial number in soil. Clearly, vermicompost has a potential to be used as an alternative to farmyard manure to improve and maintain soil biological activity in alkaline calcareous soils from the Mediterranean region of Turkey. Further studies are needed to assess its full potential for these soils. PMID:25254238

Uz, Ilker; Tavali, Ismail Emrah

2014-01-01

143

Short-term effect of vermicompost application on biological properties of an alkaline soil with high lime content from Mediterranean region of Turkey.  

PubMed

This study was conducted to investigate direct short-term impact of vermicompost on some soil biological properties by monitoring changes after addition of vermicompost as compared to farmyard manure in an alkaline soil with high lime content from semiarid Mediterranean region of Turkey. For this purpose, mixtures of soil and organic fertilizers in different doses were incubated under greenhouse condition. Soil samples collected in regular intervals were analyzed for biological parameters including dehydrogenase, ?-glucosidase, urease, alkaline phosphatase activities, and total number of aerobic mesophilic bacteria. Even though soil dehydrogenase activity appeared to be dose-independent based on overall evaluation, organic amendments were found to elevate dehydrogenase activity when sampling periods are evaluated individually. ?-glucosidase, urease, alkaline phosphatase activity, and aerobic mesophilic bacterial numbers in vermicompost treatments fluctuated but remained significantly above the control. A slight but statistically significant difference was detected between organic amendments in terms of urease activity. Vermicompost appeared to more significantly increase bacterial number in soil. Clearly, vermicompost has a potential to be used as an alternative to farmyard manure to improve and maintain soil biological activity in alkaline calcareous soils from the Mediterranean region of Turkey. Further studies are needed to assess its full potential for these soils. PMID:25254238

Uz, Ilker; Tavali, Ismail Emrah

2014-01-01

144

Northeastern Naturalist Vol. 16, Special Issue 5422 Biology of Ultramafic Rocks and Soils  

E-print Network

Northeastern Naturalist Vol. 16, Special Issue 5422 Biology of Ultramafic Rocks and Soils: Research. Geology and Soils Biologists loosely use the term "serpentine" to describe rocks that are re- ferred), and more information is needed to provide an adequate foundation. Ultramafic rocks and soils are widely

Rajakaruna, Nishanta

145

Soil moisture regulates the biological response of elevated atmospheric CO2 concentrations in a coupled  

E-print Network

Soil moisture regulates the biological response of elevated atmospheric CO2 concentrations is important, and that the effects intrinsically depend on the soil moisture state. Therefore, using a coupled models are significantly coupled to the hydrological feedback via soil moisture availability

Niyogi, Dev

146

Tree Species Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation Forests  

E-print Network

. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolanTree Species Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains

Wall, Diana

147

Long Term Fertility Monitoring of Soil Treated by the Chemical-Biological Stabilization Method  

Microsoft Academic Search

We investigated the long term fertility of soil treated by Chemical-Biological Stabilization, a patented method developed to treat tropical and semitropical sites with high concentrations of very weathered hydrocarbons, by transforming them into soil humus. The fertility in soil was studied over a three year period with respect to TPH (EPA 418.1), TCLP leachates, toxicity (Microtox), field capacity, and water

Randy H. Adams; Francisco J. Guzman-Osorio; J. Abisenas Alvarez-Rivera

148

Biologically active dichapetalins from Dichapetalum gelonioides.  

PubMed

A phytochemical investigation of the toxic tropical plant Dichapetalum gelonioides led to the isolation and identification of 14 new dichapetalins (1-14) and the known dichapetalins A (15) and K (16). The structures of the new compounds were determined by analyses of their NMR, MS, electronic circular dichroism, and X-ray diffraction data. The esterification at C-25 by 4-hydroxyphenylpropanoic acid and the hydroxylation at C-2' are unique in this unusual class of natural products. In addition to the known cytotoxicity, an array of biological activities, including antifeedant, nematicidal, antifungal, and NO and AChE inhibitory activities, were observed for this class of compounds. These findings suggested that dichapetalin hybrid triterpenoids as a class have broad biologically active cellular functions including defense against insect herbivores and pathogens. PMID:24597894

Jing, Shu-Xi; Luo, Shi-Hong; Li, Chun-Huan; Hua, Juan; Wang, Yan-Li; Niu, Xue-Mei; Li, Xiao-Nian; Liu, Yan; Huang, Chun-Shuai; Wang, Ying; Li, Sheng-Hong

2014-04-25

149

Loranthus micranthus Linn.: Biological Activities and Phytochemistry.  

PubMed

Loranthus micranthus Linn. is a medicinal plant from the Loranthaceae family commonly known as an eastern Nigeria species of the African mistletoe and is widely used in folkloric medicine to cure various ailments and diseases. It is semiparasitic plant because of growing on various host trees and shrubs and absorbing mineral nutrition and water from respective host. Hence, the phytochemicals and biological activities of L. micranthus demonstrated strong host and harvesting period dependency. The leaves have been proved to possess immunomodulatory, antidiabetic, antimicrobial, antihypertensive, antioxidant, antidiarrhoeal, and hypolipidemic activities. This review summarizes the information and findings concerning the current knowledge on the biological activities, pharmacological properties, toxicity, and chemical constituents of Loranthus micranthus. PMID:24109490

Zorofchian Moghadamtousi, Soheil; Hajrezaei, Maryam; Abdul Kadir, Habsah; Zandi, Keivan

2013-01-01

150

Loranthus micranthus Linn.: Biological Activities and Phytochemistry  

PubMed Central

Loranthus micranthus Linn. is a medicinal plant from the Loranthaceae family commonly known as an eastern Nigeria species of the African mistletoe and is widely used in folkloric medicine to cure various ailments and diseases. It is semiparasitic plant because of growing on various host trees and shrubs and absorbing mineral nutrition and water from respective host. Hence, the phytochemicals and biological activities of L. micranthus demonstrated strong host and harvesting period dependency. The leaves have been proved to possess immunomodulatory, antidiabetic, antimicrobial, antihypertensive, antioxidant, antidiarrhoeal, and hypolipidemic activities. This review summarizes the information and findings concerning the current knowledge on the biological activities, pharmacological properties, toxicity, and chemical constituents of Loranthus micranthus. PMID:24109490

Zorofchian Moghadamtousi, Soheil; Hajrezaei, Maryam; Abdul Kadir, Habsah

2013-01-01

151

Geomorphic controls on biological soil crust distribution: A conceptual model from the Mojave Desert (USA)  

NASA Astrophysics Data System (ADS)

Biological soil crusts (BSCs) are bio-sedimentary features that play critical geomorphic and ecological roles in arid environments. Extensive mapping, surface characterization, GIS overlays, and statistical analyses explored relationships among BSCs, geomorphology, and soil characteristics in a portion of the Mojave Desert (USA). These results were used to develop a conceptual model that explains the spatial distribution of BSCs. In this model, geologic and geomorphic processes control the ratio of fine sand to rocks, which constrains the development of three surface cover types and biogeomorphic feedbacks across intermontane basins. (1) Cyanobacteria crusts grow where abundant fine sand and negligible rocks form saltating sand sheets. Cyanobacteria facilitate moderate sand sheet activity that reduces growth potential of mosses and lichens. (2) Extensive tall moss-lichen pinnacled crusts are favored on early to late Holocene surfaces composed of mixed rock and fine sand. Moss-lichen crusts induce a dust capture feedback mechanism that promotes further crust propagation and forms biologically-mediated vesicular (Av) horizons. The presence of thick biogenic vesicular horizons supports the interpretation that BSCs are long-lived surface features. (3) Low to moderate density moss-lichen crusts grow on early Holocene and older geomorphic surfaces that display high rock cover and negligible surficial fine sand. Desert pavement processes and abiotic vesicular horizon formation dominate these surfaces and minimize bioturbation potential. The biogeomorphic interactions that sustain these three surface cover trajectories support unique biological communities and soil conditions, thereby sustaining ecological stability. The proposed conceptual model helps predict BSC distribution within intermontane basins to identify biologically sensitive areas, set reference conditions for ecological restoration, and potentially enhance arid landscape models, as scientists address impacts of climate change and anthropogenic disturbances.

Williams, Amanda J.; Buck, Brenda J.; Soukup, Deborah A.; Merkler, Douglas J.

2013-08-01

152

Biological and Environmental Engineering Soil & Water Research Group  

E-print Network

elevation models (DEM) and SSURGO soils data. This grid incorporates SSURGO soils data into the index class data will be sent to the email address. To download the SSURGO soil data, click on "Select State Data". Since SSURGO data are distributed on the county basis, downloading all the desired soil data may

Walter, M.Todd

153

A New Extreme Environment for Aerobic Anoxygenic Phototrophs: Biological Soil Crusts  

Microsoft Academic Search

\\u000a Biological soil crusts improve the health of arid or semiarid soils by enhancing water content, nutrient relations and mechanical\\u000a stability, facilitated largely by phototrophic microorganisms. Until recently, only oxygenic phototrophs were known from soil\\u000a crusts. A recent study has demonstrated the presence of aerobic representatives of Earth’s second major photosynthetic clade,\\u000a the evolutionarily basal anoxygenic phototrophs. Three Canadian soil crust

Julius T. Csotonyi; Jolantha Swiderski; Erko Stackebrandt; Vladimir Yurkov

154

Soil organic carbon buffers heavy metal contamination on semiarid soils: Effects of different metal threshold levels on soil microbial activity  

Microsoft Academic Search

Traditionally, three threshold levels have been accepted for heavy metal concentrations in agricultural soils, depending on soil pH. The aim of this work was to ascertain how the three threshold values proposed for Cd (3, 6.5, and 12.5 mg kg?1) and Zn (300, 650, and 1300 mg kg?1) really affect soil microbial activity. Two soils, a scrubland soil and a forest soil, differing widely

J. L. Moreno; F. Bastida; M. Ros; T. Hernández; C. García

2009-01-01

155

Soil and Water Conservation Activities for Scouts.  

ERIC Educational Resources Information Center

The purpose of the learning activities outlined in this booklet is to help Scouts understand some conservation principles which hopefully will lead to the development of an attitude of concern for the environment and a commitment to help with the task of using and managing soil, water, and other natural resources for long range needs as well as…

Soil Conservation Service (USDA), Washington, DC.

156

Carbon accumulation by biological soil crusts in relation to relief and sampling depth  

NASA Astrophysics Data System (ADS)

In arid and semiarid ecosystems the soil surface is covered by biological soil crusts (BSC). These BSC are microbial communities of cyanobacteria, lichens and mosses. Due to the photosynthetic activity of these microorganisms, BSC are main carbon contributors to arid ecosystems. The cover is related to ecosystem functions like surface stabilization, water redistribution and nutrient fixation. These functions rely on the microbial community composition of the BSC. Cyanobacteria and cyanolichens excrete exopolysaccharides, which build microaggregates with soil particles. This stabilizes and seals the soil surface. Therefore cyanobacteria and cyanolichen dominated crusts introduce runoff, which affects the distribution of carbon. The total amount of soil organic carbon was determined in relation to the relief position and BSC thickness showing a strong correlation between relief, sampling depth and carbon amounts. At the Arid Ecosystem Research Center (AERC) station of the Nizzana sand dunes (NW Negev, Israel) the dunes and the interdune corridor are covered by BSC up to 80% of the total area. The BSC are composed of a thin topcrust section and a mineral subcrust section. The overall thickness changes in relation to the relief position. Along a dune transect topcrust and subcrust samples were taken and analyzed on their C_org, C_carb, and C_total concentration. The total amount of carbon (g m^-2) was calculated from the carbon concentrations, the BSC bulk density and the sampling depth. Comparing the topcrust and subcrust values of the sampling points the topcrust sections showed 3-4 times higher concentrations of organic carbon than the subcrust sections. The light intensity decreases with soil depth, resulting in a higher biological activity and carbon fixation in the topcrust sections. The subcrust showed relative higher amounts of C_carb contributing to the soil surface stability. Depending on the relief position the total amount of accumulated carbon was 4 times higher at the interdune positions than at the top slope. The data shows a high dependence of total carbon storage by BSC on the relief position and the high importance of the separate crust sections for the accumulation of C_org and C_carb.

Jetter, Stefan; Drahorad, Sylvie; Felix-Henningsen, Peter

2010-05-01

157

The chemical activities of the Viking biology experiments and the arguments for the presence of superoxides, peroxides, gamma-Fe2O3 and carbon suboxide polymer in the Martian soil  

NASA Technical Reports Server (NTRS)

The evolution of N2, Ar, O2, and CO2 from Martian soil as a function of humidity in the Gas Exchange Experiment are correlated with the mean level of water vapor in the Martian atmosphere. All but O2 are associated with desorption. The evolution of oxygen is consistent with the presence of alkaline earth and alkali metal superoxides; and their peroxides and the gamma-Fe2O3 in the soil can account for the generation of radioactive gas in the Labeled Release Experiment. The slower evolution of CO2 from both the Gas Exchange Experiment and the Labeled Release Experiment are associated with the direct oxidation of organics by gamma-Fe2O3. The Pyrolytic Release Experiment's second peak may be carbon suboxide as demonstrated by laboratory experiments. A necessary condition is that the polymer exists in the Martian soil. We ascribe the activity of the surface samples to the reaction of Martian particulates with an anhydrous CO2 atmosphere activated by uv and ionizing radiations. The surface particles are ultimately altered by exposure to small but significant amounts of water at the sites. From the working model, we have predicted the peculiar nature of the chemical entities and demonstrated that the model is justified by laboratory data. The final confirmation of this model will entail a return to Mars, but the nature and implications of this chemistry for the Martian surface is predicted to reveal even more about Mars with further simulations in the laboratory.

Oyama, V. I.; Berdahl, B. J.; Woeller, F.; Lehwalt, M.

1978-01-01

158

Monitoring Biological Activity at Geothermal Power Plants  

SciTech Connect

The economic impact of microbial growth in geothermal power plants has been estimated to be as high as $500,000 annually for a 100 MWe plant. Many methods are available to monitor biological activity at these facilities; however, very few plants have any on-line monitoring program in place. Metal coupon, selective culturing (MPN), total organic carbon (TOC), adenosine triphosphate (ATP), respirometry, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE) characterizations have been conducted using water samples collected from geothermal plants located in California and Utah. In addition, the on-line performance of a commercial electrochemical monitor, the BIoGEORGE?, has been evaluated during extended deployments at geothermal facilities. This report provides a review of these techniques, presents data on their application from laboratory and field studies, and discusses their value in characterizing and monitoring biological activities at geothermal power plants.

Peter Pryfogle

2005-09-01

159

Generation and Biological Activities of Oxidized Phospholipids  

PubMed Central

Abstract Glycerophospholipids represent a common class of lipids critically important for integrity of cellular membranes. Oxidation of esterified unsaturated fatty acids dramatically changes biological activities of phospholipids. Apart from impairment of their structural function, oxidation makes oxidized phospholipids (OxPLs) markers of “modified-self” type that are recognized by soluble and cell-associated receptors of innate immunity, including scavenger receptors, natural (germ line-encoded) antibodies, and C-reactive protein, thus directing removal of senescent and apoptotic cells or oxidized lipoproteins. In addition, OxPLs acquire novel biological activities not characteristic of their unoxidized precursors, including the ability to regulate innate and adaptive immune responses. Effects of OxPLs described in vitro and in vivo suggest their potential relevance in different pathologies, including atherosclerosis, acute inflammation, lung injury, and many other conditions. This review summarizes current knowledge on the mechanisms of formation, structures, and biological activities of OxPLs. Furthermore, potential applications of OxPLs as disease biomarkers, as well as experimental therapies targeting OxPLs, are described, providing a broad overview of an emerging class of lipid mediators. Antioxid. Redox Signal. 12, 1009–1059. PMID:19686040

Oskolkova, Olga V.; Birukov, Konstantin G.; Levonen, Anna-Liisa; Binder, Christoph J.; Stockl, Johannes

2010-01-01

160

Effect of soil type and soil management on soil physical, chemical and biological properties in commercial organic olive orchards in Southern Spain  

NASA Astrophysics Data System (ADS)

One of the objectives of organic agriculture is to maintain and improve soil quality, while simultaneously producing an adequate yield. A key element in organic olive production is soil management, which properly implemented can optimize the use of rainfall water enhancing infiltration rates and controlling competition for soil water by weeds. There are different soil management strategies: eg. weed mowing (M), green manure with surface tillage in spring (T), or combination with animal grazing among the trees (G). That variability in soil management combined with the large variability in soil types on which organic olive trees are grown in Southern Spain, difficult the evaluation of the impact of different soil management on soil properties, and yield as well as its interpretation in terms of improvement of soil quality. This communications presents the results and analysis of soil physical, chemical and biological properties on 58 soils in Southern Spain during 2005 and 2006, and analyzed and evaluated in different studies since them. Those 58 soils were sampled in 46 certified commercial organic olive orchards with four soil types as well as 12 undisturbed areas with natural vegetation near the olive orchards. The four soil types considered were Eutric Regosol (RGeu, n= 16), Eutric Cambisol (CMeu, n=16), Calcaric Regosol (RGca, n=13 soils sampled) and Calcic Cambisol (CMcc), and the soil management systems (SMS) include were 10 light tillage (LT), 16 sheep grazing (G), 10 tillage (T), 10 mechanical mowing (M), and 12 undisturbed areas covered by natural vegetation (NV-C and NV-S). Our results indicate that soil management had a significant effect on olive yield as well as on key soil properties. Among these soil properties are physical ones, such as infiltration rate or bulk density, chemical ones, especially organic carbon concentration, and biological ones such as soil microbial respiration and bacterial community composition. Superimpose to that soil management induced variability, there was a strong interaction with soil type and climate conditions. There was also a relatively high variability within the same soil management and soil type class, indicating farm to farm variability in conditions and history of soil management. Based on this dataset two different approaches were taken to: A) evaluate the risk of soil degradation based on a limited set of soil properties, B) assess the effect of changes in SMS on soil biodiversity by using terminal restriction profiles (TRFs) derived from T-RFLP analysis of amplified 16S rDNA as. The results indicates the potential of both approaches to assess the risk of soil degradation (A) and the impact on soil biodiversity (B) upon appropriate benchmarking to characterize the interaction between soil management and soil type References Álvarez, S., Soriano, M.A., Landa, B.B., and Gómez, J.A. 2007. Soil properties in organic olive orchards compared with that in natural areas in a mountainous landscape in southern Spain. Soil Use Manage 23:404-416. Gómez, J.A., Álvarez, S., and Soriano, M.A. 2009. Development of a soil degradation assessment tool for organic olive groves in southern Spain. Catena 79:9-17. Landa, B.B., Montes-Borrego, M., Aranda, S., Soriano, M.A., Gómez, J.A., and Navas-Cortés, J.A. 2013. Soil factors involved in the diversity and structure of soil bacterial communities in commercial organic olive orchards in Southern Spain. Environmental Microbiology Reports (accepted) Soriano, M.A., Álvarez, S., Landa, B.B., and Gómez, J.A. 2013. Soil properties in organic olive orchards following different weed management in a rolling landscape of Andalusia, Spain. Renew Agr Food Syst (in press), doi:10.1017/S1742170512000361.

Gomez, Jose Alfonso; Auxiliadora Soriano, Maria; Montes-Borrego, Miguel; Navas, Juan Antonio; Landa, Blanca B.

2014-05-01

161

Smectite clays in Mars soil - Evidence for their presence and role in Viking biology experimental results  

NASA Technical Reports Server (NTRS)

Evidence for the presence of smectite clays in Martian soils is reviewed and results of experiments with certain active clays simulating the Viking biology experiments are reported. Analyses of Martian soil composition by means of X-ray fluorescence spectrometry and dust storm spectroscopy and Martian geological history strongly suggest the presence of a mixture of weathered ferro-silicate minerals, mainly nontronite and montmorillonite, accompanied by soluble sulphate salts, as major constituents. Samples of montmorillonite and nontronite incubated with (C-14)-formate or the radioactive nutrient medium solution used in the Viking Labeled Release experiment, were found to produce patterns of release of radioactive gas very similar to those observed in the Viking experiments, indicating the iron-catalyzed decomposition of formate as the reaction responsible for the Viking results. The experimental results of Hubbard (1979) simulating the results of the Viking Pyrolytic Release experiment using iron montmorillonites are pointed out, and it is concluded that many of the results of the Viking biology experiments can be explained in terms of the surface activity of smectite clays in catalysis and adsorption.

Banin, A.; Rishpon, J.

1979-01-01

162

Rapid Recovery of Cyanobacterial Pigments in Desiccated Biological Soil Crusts following Addition of Water.  

PubMed

We examined soil surface colour change to green and hydrotaxis following addition of water to biological soil crusts using pigment extraction, hyperspectral imaging, microsensors and 13C labeling experiments coupled to matrix-assisted laser desorption and ionization time of flight-mass spectrometry (MALD-TOF MS). The topsoil colour turned green in less than 5 minutes following water addition. The concentrations of chlorophyll a (Chl a), scytonemin and echinenon rapidly increased in the top <1 mm layer while in the deeper layer, their concentrations remained low. Hyperspectral imaging showed that, in both wet and dehydrated crusts, cyanobacteria formed a layer at a depth of 0.2-0.4 mm and this layer did not move upward after wetting. 13C labeling experiments and MALDI TOF analysis showed that Chl a was already present in the desiccated crusts and de novo synthesis of this molecule started only after 2 days of wetting due to growth of cyanobacteria. Microsensor measurements showed that photosynthetic activity increased concomitantly with the increase of Chl a, and reached a maximum net rate of 92 µmol m-2 h-1 approximately 2 hours after wetting. We conclude that the colour change of soil crusts to green upon water addition was not due to hydrotaxis but rather to the quick recovery and reassembly of pigments. Cyanobacteria in crusts can maintain their photosynthetic apparatus intact even under prolonged periods of desiccation with the ability to resume their photosynthetic activities within minutes after wetting. PMID:25375172

Abed, Raeid M M; Polerecky, Lubos; Al-Habsi, Amal; Oetjen, Janina; Strous, Marc; de Beer, Dirk

2014-01-01

163

Rapid Recovery of Cyanobacterial Pigments in Desiccated Biological Soil Crusts following Addition of Water  

PubMed Central

We examined soil surface colour change to green and hydrotaxis following addition of water to biological soil crusts using pigment extraction, hyperspectral imaging, microsensors and 13C labeling experiments coupled to matrix-assisted laser desorption and ionization time of flight-mass spectrometry (MALD-TOF MS). The topsoil colour turned green in less than 5 minutes following water addition. The concentrations of chlorophyll a (Chl a), scytonemin and echinenon rapidly increased in the top <1 mm layer while in the deeper layer, their concentrations remained low. Hyperspectral imaging showed that, in both wet and dehydrated crusts, cyanobacteria formed a layer at a depth of 0.2–0.4 mm and this layer did not move upward after wetting. 13C labeling experiments and MALDI TOF analysis showed that Chl a was already present in the desiccated crusts and de novo synthesis of this molecule started only after 2 days of wetting due to growth of cyanobacteria. Microsensor measurements showed that photosynthetic activity increased concomitantly with the increase of Chl a, and reached a maximum net rate of 92 µmol m?2 h?1 approximately 2 hours after wetting. We conclude that the colour change of soil crusts to green upon water addition was not due to hydrotaxis but rather to the quick recovery and reassembly of pigments. Cyanobacteria in crusts can maintain their photosynthetic apparatus intact even under prolonged periods of desiccation with the ability to resume their photosynthetic activities within minutes after wetting. PMID:25375172

Abed, Raeid M. M.; Polerecky, Lubos; Al-Habsi, Amal; Oetjen, Janina; Strous, Marc; de Beer, Dirk

2014-01-01

164

Soil drainage as an active agent of recent soil evolution: a David Montagnea,b  

E-print Network

1 Soil drainage as an active agent of recent soil evolution: a review* David Montagnea,b , Sophie Cornua , Lydie Le Forestierc , Isabelle Cousina a INRA-UR 0272, Unité de Science du Sol, centre de on pedogenesis mainly focuses on the long-term soil formation and most often neglects recent soil evolution

Boyer, Edmond

165

Biological activities of isatin and its derivatives.  

PubMed

Isatin is an endogenous compound identified in humans that possesses a wide range of biological activities. Isatin has anxiogenic, sedative, anticonvulsant activities and acts as a potent antagonist on atrial natriuretic peptide receptors in vitro. A series of p-substituted isatin semicarbazones have shown anticonvulsant activity in MES, scPTZ and scSTY tests. Various isatin-N-Mannich bases of isatin-3-thiosemicarbazones have shown antiviral and tuberculostatic activity. Methisazone is an effective compound against variola and vaccinia viruses. The N-dimethyl and morpholino derivative of 5-methyl isatin and trimethoprim exhibited an EC50 of more than 4.3 and 17.7 mg mL(-1), respectively. Isatin (3-o-nitrophenyl) hydrazone has shown activity against Walker carcinoma-256. Various substituted indolinones showed antitubercular activity against M. tuberculosis H37Rv with MIC ranging from 10-20 microg mL(-1). Isatin derivatives of Mannich bases had fibrinolytic, muscle relaxant, antiallergic, immunosuppressant, and antithrombotic activity. Isatin showed cardioinhibitory effect on frog heart, and hypotensive, respiratory depression and antidiuretic effects. PMID:15907222

Pandeya, Surendra Nath; Smitha, Sivakumar; Jyoti, Mayank; Sridhar, Seshaiah Krishnan

2005-03-01

166

Field management effects on soil enzyme activities  

Microsoft Academic Search

There is growing recognition for the need to develop sensitive indicators of soil quality that reflect the effects of land management on soil and assist land managers in promoting long-term sustainability of terrestrial ecosystems. Eleven soil enzymes assays were investigated relative to soil management and soil quality at two study sites. Soils were sampled from the Vegetable Crop Rotation Plots

Anna K. Bandick; Richard P. Dick

1999-01-01

167

Long-term impact of acid resin waste deposits on soil quality of forest areas II. Biological indicators.  

PubMed

In this study, we evaluated the effects of two acid resin deposits on the soil microbiota of forest areas by means of biomass, microbial activity-related estimations and simple biological ratios. The determinations carried out included: total DNA yield, basal respiration, intracellular enzyme activities (dehydrogenase and catalase) and extracellular enzyme activities involved in the cycles of C (beta-glucosidase and chitinase), N (protease) and P (acid-phosphatase). The calculated ratios were: total DNA/total N; basal respiration/total DNA; dehydrogenase/total DNA and catalase/total DNA. Total DNA yield was used to estimate soil microbial biomass. Results showed that microbial biomass and activity were severely inhibited in the deposits, whilst resin effects on contaminated zones were variable and site-dependant. Correlation analysis showed no clear effect of contaminants on biomass and activities outside the deposits, but a strong interdependence with natural organic matter related parameters such as total N. In contrast, by using simple ratios we could detect more stressful conditions in terms of organic matter turnover and basal metabolism in contaminated areas compared to their uncontaminated counterparts. These results stress that developed ecosystems such as forests can buffer the effects of pollutants and preserve high functionality via natural attenuation mechanisms, but also that acid resins can be toxic to biological targets negatively affecting soil dynamics. Acid resin deposits can therefore act as contaminant sources adversely altering soil processes and reducing the environmental quality of affected areas despite the solid nature of these wastes. PMID:18768212

Pérez-de-Mora, Alfredo; Madejón, Engracia; Cabrera, Francisco; Buegger, Franz; Fuss, Roland; Pritsch, Karin; Schloter, Michael

2008-11-15

168

Hydrogen Peroxide Decay in Waters with Suspended Soils: Evidence for Biologically Mediated Processes.  

National Technical Information Service (NTIS)

Hydrogen peroxide decay studies have been conducted in suspensions of several well-characterized soils and in natural water samples. Kinetic and product studies indicated that the decay was biologically mediated and could be described by psuedo first-orde...

W. J. Cooper, R. G. Zepp

1990-01-01

169

ADSORPTION, MOVEMENT, AND BIOLOGICAL DEGRADATION OF LARGE CONCENTRATIONS OF SELECTED PESTICIDES IN SOILS  

EPA Science Inventory

Because of the importance of soil in biologically reducing the quantity and retarding the rate of pollutant movement into groundwater, this laboratory study was initiated to evaluate the adsorption, mobility, and degradation of large concentrations of the pesticide atrazine, meth...

170

Biological Activities of Polyphenols from Grapes  

PubMed Central

The dietary consumption of grape and its products is associated with a lower incidence of degenerative diseases such as cardiovascular disease and certain types of cancers. Most recent interest has focused on the bioactive phenolic compounds in grape. Anthocyanins, flavanols, flavonols and resveratrol are the most important grape polyphenols because they possess many biological activities, such as antioxidant, cardioprotective, anticancer, anti-inflammation, antiaging and antimicrobial properties. This review summarizes current knowledge on the bioactivities of grape phenolics. The extraction, isolation and identification methods of polyphenols from grape as well as their bioavailability and potential toxicity also are included. PMID:20386657

Xia, En-Qin; Deng, Gui-Fang; Guo, Ya-Jun; Li, Hua-Bin

2010-01-01

171

ORIGINAL PAPER Soil enzyme activities as potential indicators  

E-print Network

ORIGINAL PAPER Soil enzyme activities as potential indicators of soluble organic nitrogen pools on soil nitrogen status. As a major process affecting the soil-soluble organic nitrogen pool, degradation of insoluble organic nitrogen in the production of soluble organic nitrogen is mediated by a suite of soil

Paris-Sud XI, Université de

172

NO gas loss from biologically crusted soils in Canyonlands National Park, Utah  

USGS Publications Warehouse

In this study, we examined N gas loss as nitric oxide (NO) from N-fixing biologically crusted soils in Canyonlands National Park, Utah. We hypothesized that NO gas loss would increase with increasing N fixation potential of the biologically crusted soil. NO fluxes were measured from biologically crusted soils with three levels of N fixation potential (Scytonema-Nostoc-Collema spp. (dark)>Scytonema-Nostoc-Microcoleus spp. (medium)>Microcoleus spp. (light)) from soil cores and field chambers. In both cores and field chambers there was a significant effect of crust type on NO fluxes, but this was highly dependent on season. NO fluxes from field chambers increased with increasing N fixation potential of the biologically crusted soils (dark>medium>light) in the summer months, with no differences in the spring and autumn. Soil chlorophyllasis Type a content (an index of N fixation potential), percent N, and temperature explained 40% of the variability in NO fluxes from our field sites. Estimates of annual NO loss from dark and light crusts was 0.04-0.16 and 0.02-0.11-N/ha/year. Overall, NO gas loss accounts for approximately 3-7% of the N inputs via N fixation in dark and light biologically crusted soils. Land use practices have drastically altered biological soil crusts communities over the past century. Livestock grazing and intensive recreational use of public lands has resulted in a large scale conversion of dark cyanolichen crusts to light cyanobacterial crusts. As a result, changes in biologically crusted soils in arid and semi-arid regions of the western US may subsequently impact regional NO loss. ?? Springer 2005.

Barger, N.N.; Belnap, J.; Ojima, D.S.; Mosier, A.

2005-01-01

173

Biological activity and tentative identification of flavonoid components in velvetleaf ( Abutilon theophrasti Medik.) seed coats  

Microsoft Academic Search

The biological activity of aqueous extracts of velvetleaf (Abutilontheophrasti Medik.) seed coats and their flavonoid components against three plant species and five soil fungi was investigated. Aqueous extracts slightly inhibited germination and significantly inhibited radicle growth of all plant species tested. Fungal growth was inhibited or not affected, depending on species, by aqueous extracts. The aqueous extracts were extracted into

Wojciech L. Paszkowski; Robert J. Kremer

1988-01-01

174

Biological Degradation of Common Pharmaceuticals and Personal Care Products in Soils with High Water Content  

Microsoft Academic Search

Biological degradation rates of six pharmaceuticals and personal care products were examined in soil from a land application\\u000a site and in adjacent soil with no prior history of effluent exposure. Microbial degradation rates were compared over 2 weeks\\u000a under standing water or saturated conditions and draining conditions after having been saturated for 3 days. Biological degradation\\u000a of 17?-estradiol exhibited rapid rates of

Deborah L. Carr; Audra N. Morse; John C. Zak; Todd A. Anderson

2011-01-01

175

Variation in total biological productivity and soil microbial biomass in rainfed agroecosystems: Impact of application of herbicide and soil amendments  

Microsoft Academic Search

Total biological productivity and soil microbial biomass are important characteristics to describe sustainable agroecosystems. We investigated the impact of herbicide, alone or in combination with soil amendments, on crop and weed productivity and microbial biomass in a rice (Oryza sativa)–barley (Hordeum vulgare)–summer fallow rotation in a tropical rainfed agroecosystem. Total net productivity (TNP) of crops was greater with herbicide (Butachlor)+chemical

Pratibha Singh; Nandita Ghoshal

2010-01-01

176

Development of soil chemical and biological properties in the initial stages of post-mining deposition sites.  

PubMed

The aim of this study was to assess the seasonal development of the physicochemical (pH, organic C, organic N, extractable P, Ca(2+), Mg(2+)) and biological soil properties (microbial biomass, activities of urease, dehydrogenase and alkaline phosphatase) of the topsoil of mine deposition sites that differed based on the material used exclusively for their creation: (a) marlstones, (b) red-grey formations (RGF), and (c) fly ash (FA), during the first year after their creation. Our hypothesis was that all deposition sites, regardless the material they consist of, present equal opportunities for the establishment of spontaneous vegetation. All macronutrients concentrations (P, Ca(2+), and Mg(2+)) remained constant with time and were found to be higher in the FA sites. Organic C, organic N, all enzyme activities, and microbial biomass were higher in the RGF and marl depositions, with marl sites presenting the highest values. All values of biological variables, with the exception of alkaline phosphatase, increased with time. The alkaline environment along with the slow improvement in soil biological properties of the FA sites seemed to present the most unfavorable conditions for spontaneous vegetation growth. On the contrary, the other two spoil materials presented significant improvement in the initial stages of soil formation in terms of soil functionality. PMID:25249044

Monokrousos, Nikolaos; Boutsis, George; Diamantopoulos, John D

2014-12-01

177

Soil Biology & Biochemistry 38 (2006) 30353040 Biotic interactions in Antarctic terrestrial ecosystems: Are they a factor?  

E-print Network

Zealand b British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road in structuring Antarctic soil environments. r 2006 Elsevier Ltd. All rights reserved. Keywords: BioticSoil Biology & Biochemistry 38 (2006) 3035�3040 Biotic interactions in Antarctic terrestrial

Wall, Diana

178

Nutrient availability affects pigment production but not growth in lichens of biological soil crusts  

Microsoft Academic Search

Recent research suggests that micronutrients such as Mn may limit growth of slow-growing biological soil crusts (BSCs) in some of the drylands of the world. These soil surface communities contribute strongly to arid ecosystem function and are easily degraded, creating a need for new restoration tools. The possibility that Mn fertilization could be used as a restoration tool for BSCs

Matthew A. Bowker; George W. Koch; Jayne Belnap; Nancy C. Johnson

2008-01-01

179

EVIDENCE FOR MICRONUTRIENT LIMITATION OF BIOLOGICAL SOIL CRUSTS: IMPORTANCE TO ARID-LANDS RESTORATION  

Microsoft Academic Search

Desertification is a global problem, costly to national economies and human societies. Restoration of biological soil crusts (BSCs) may have an important role to play in the reversal of desertification due to their ability to decrease erosion and enhance soil fertility. To determine if there is evidence that lower fertility may hinder BSC recolonization, we investigated the hypothesis that BSC

Matthew A. Bowker; Jayne Belnap; Diane W. Davidson; Susan L. Phillips

2005-01-01

180

Hydrazine degradation and its effect on microbial activity in soil  

SciTech Connect

Considerable information has been accumulated on the toxicity of hydrazine to soil bacterial cultures and on the degradation of hydrazne by soil bacterial cultures. The activities of the autotrophic nitrifiers Nitrosomonas and Nitrobacter and of denitrifying bacteria, and the growth of Enterobacter cloacae, were all inhibited by hydrazine. An enzyme system has been found in heterotrophic N/sub 2/-fixing bacteria capable of degrading hydrazine. Information concerning the effect of hydrazine on microbial activity in soils is not available, however. Accidental spills to soil can occur during transportation and storage. Therefore, this study was initiated to determine degradation rates of hydrazine in soils and its effect on soil microbial activity.

Ou, L.T.; Street, J.J.

1987-01-01

181

Spectroscopic study of biologically active glasses  

NASA Astrophysics Data System (ADS)

It is known that the chemical activity phenomenon is characteristic for some inorganic glasses and they are able to participate in biological processes of living organisms (plants, animals and human bodies). An example here is the selective removal of silicate-phosphate glass components under the influence of biological solutions, which has been applied in designing glasses acting as ecological fertilizers of controlled release rate of the nutrients for plants. The structure of model silicate-phosphate glasses containing the different amounts of the glass network formers, i.e. Ca 2+ and Mg 2+, as a binding components were studied. These elements besides other are indispensable of the normal growth of plants. In order to establish the function and position occupied by the particular components in the glass structure, the glasses were examined by FTIR spectroscopy (with spectra decomposition) and XRD methods. It has been found that the increasing amount of MgO in the structure of silicate-phosphate glasses causes the formation of domains the structure of which changes systematically from a structure of the cristobalite type to a structure corresponding to forsterite type. Whilst the increasing content of CaO in the structure of silicate-phosphate glasses causes the formation of domains the structure of which changes from a structure typical for cristobalite through one similar to the structure of calcium orthophosphate, to a structure corresponding to calcium silicates. The changing character of domains structure is the reason of different chemical activity of glasses.

Szumera, M.; Wac?awska, I.; Mozgawa, W.; Sitarz, M.

2005-06-01

182

Biological Treatment of Petroleum in Radiologically Contaminated Soil  

Microsoft Academic Search

This chapter describes ex situ bioremediation of the petroleum portion of radiologically co-contaminated soils using microorganisms isolated from a waste site and innovative bioreactor technology. Microorganisms first isolated and screened in the laboratory for bioremediation of petroleum were eventually used to treat soils in a bioreactor. The bioreactor treated soils contaminated with over 20,000 mg\\/kg total petroleum hydrocarbon and reduced

2005-01-01

183

Modification of soil microbial activity and several hydrolases in a forest soil artificially contaminated with copper  

NASA Astrophysics Data System (ADS)

Soils have long been exposed to the adverse effects of human activities, which negatively affect soil biological activity. As a result of their functions and ubiquitous presence microorganisms can serve as environmental indicators of soil pollution. Some features of soil microorganisms, such as the microbial biomass size, respiration rate, and enzyme activity are often used as bioindicators of the ecotoxicity of heavy metals. Although copper is essential for microorganisms, excessive concentrations have a negative influence on processes mediated by microorganisms. In this study we measured the response of some microbial indicators to Cu pollution in a forest soil, with the aim of evaluating their potential for predicting Cu contamination. Samples of an Ah horizon from a forest soil under oakwood vegetation (Quercus robur L.) were contaminated in the laboratory with copper added at different doses (0, 120, 360, 1080 and 3240 mg kg-1) as CuCl2×2H2O. The soil samples were kept for 7 days at 25 °C and at a moisture content corresponding to the water holding capacity, and thereafter were analysed for carbon and nitrogen mineralization capacity, microbial biomass C, seed germination and root elongation tests, and for urease, phosphomonoesterase, catalase and ß-glucosidase activities. In addition, carbon mineralization kinetics were studied, by plotting the log of residual C against incubation time, and the metabolic coefficient, qCO2, was estimated. Both organic carbon and nitrogen mineralization were lower in polluted samples, with the greatest decrease observed in the sample contaminated with 1080 mg kg-1. In all samples carbon mineralization followed first order kinetics; the C mineralization constant was lower in contaminated than in uncontaminated samples and, in general, decreased with increasing doses of copper. Moreover, it appears that copper contamination not only reduced the N mineralization capacity, but also modified the N mineralization process, since in the contaminated samples all of the inorganic nitrogen was present as ammonium, probably because of inhibition of nitrification. There was a marked decrease in biomass-C with addition of copper, and the decrease was more acute at intermediate doses (average decrease, 73%). Despite the decreases in microbial biomass and mineralized C, the value of qCO2 increased after the addition of copper. Urease activity was strongly affected by the presence of copper and the decrease was proportional to the dose; the activity at the highest dose was only 96% of that in the uncontaminated sample. Phosphomonoesterase activity was also affected by addition of copper; the reduction in activity was less than for urease and the greatest reduction was observed for the dose of 1080 mg kg-1 of copper. Catalase activity was affected by the contamination, but no clear trend was observed in relation to the dose of copper. ß-glucosidase was scarcely modified by the contamination but an increase in activity was observed at the highest dose of copper. Seed germination was not affected by copper contamination, since it only showed a clear decrease for the sample contaminated with the highest dose of copper, while root elongation decreased sharply with doses higher than 120 mg kg-1 of copper. The combined germination-elongation index followed a similar pattern to that of root elongation. For all investigated properties showing a reduction of more than 50%, the response to copper contamination was fitted to a sigmoidal dose-response model, in order to estimate the ED50 values. The ED50 values were calculated for microbial biomass, urease, root elongation and germination-elongation index, and similar values were obtained, ranging from 340 to 405 mg kg-1 Cu. The ED50 values may therefore provide a good estimation of soil deterioration.

Bellas, Rosa; Leirós, M? Carmen; Gil-Sotres, Fernando; Trasar-Cepeda, Carmen

2010-05-01

184

Effects of electrokinetic treatment of a heavy metal contaminated soil on soil enzyme activities  

Microsoft Academic Search

There is a growing concern on the potential application of a direct current (DC) electric field to soil for removing contaminants, but little is known about its impact on soil enzyme activities. This study investigated the change of enzyme activities of a heavy metal contaminated soil before and after electrokinetic (EK) treatments at lab-scale and the mechanisms of EK treatment

Long Cang; Dong-Mei Zhou; Quan-Ying Wang; Dan-Ya Wu

2009-01-01

185

Microbial activities in soil amended with sewage sludges  

Microsoft Academic Search

Microbial populations and enzyme activities in a Light-colored Andosol amended with sewage sludges were studied in relation to the decomposition of the sludges. Six kinds of sewage sludges were mixed with the soil at rates of 5 and 1%. Subsequently, the mineralization of C and N, numbers of soil microorganisms, and activities of soil enzymes were determined during an 8-week

Hiroyuki Hattori

1988-01-01

186

Activity of Soil Dehydrogenases, Urease, and Acid and Alkaline Phosphatases in Soil Polluted with Petroleum  

Microsoft Academic Search

This study was undertaken to (1) determine the effects of petroleum pollution on changes in the biochemical properties of soil and (2) demonstrate whether the application of compost, bentonite, and calcium oxide is likely to restore biological balance. Petroleum soil pollution at a dose ranging from 2.5 to 10 cm\\/kg disturbed the biochemical balance as evidenced by inhibition of the

Jadwiga Wyszkowska; Miros?aw Wyszkowski

2010-01-01

187

Soil physicochemical and biological properties of paddy-upland rotation: a review.  

PubMed

Paddy-upland rotation is an unavoidable cropping system for Asia to meet the increasing demand for food. The reduction in grain yields has increased the research interest on the soil properties of rice-based cropping systems. Paddy-upland rotation fields are unique from other wetland or upland soils, because they are associated with frequent cycling between wetting and drying under anaerobic and aerobic conditions; such rotations affect the soil C and N cycles, make the chemical speciation and biological effectiveness of soil nutrient elements varied with seasons, increase the diversity of soil organisms, and make the soil physical properties more difficult to analyze. Consequently, maintaining or improving soil quality at a desirable level has become a complicated issue. Therefore, fully understanding the soil characteristics of paddy-upland rotation is necessary for the sustainable development of the system. In this paper, we offer helpful insight into the effect of rice-upland combinations on the soil chemical, physical, and biological properties, which could provide guidance for reasonable cultivation management measures and contribute to the improvement of soil quality and crop yield. PMID:24995366

Zhou, Wei; Lv, Teng-Fei; Chen, Yong; Westby, Anthony P; Ren, Wan-Jun

2014-01-01

188

Soil Physicochemical and Biological Properties of Paddy-Upland Rotation: A Review  

PubMed Central

Paddy-upland rotation is an unavoidable cropping system for Asia to meet the increasing demand for food. The reduction in grain yields has increased the research interest on the soil properties of rice-based cropping systems. Paddy-upland rotation fields are unique from other wetland or upland soils, because they are associated with frequent cycling between wetting and drying under anaerobic and aerobic conditions; such rotations affect the soil C and N cycles, make the chemical speciation and biological effectiveness of soil nutrient elements varied with seasons, increase the diversity of soil organisms, and make the soil physical properties more difficult to analyze. Consequently, maintaining or improving soil quality at a desirable level has become a complicated issue. Therefore, fully understanding the soil characteristics of paddy-upland rotation is necessary for the sustainable development of the system. In this paper, we offer helpful insight into the effect of rice-upland combinations on the soil chemical, physical, and biological properties, which could provide guidance for reasonable cultivation management measures and contribute to the improvement of soil quality and crop yield. PMID:24995366

Lv, Teng-Fei; Chen, Yong; Westby, Anthony P.; Ren, Wan-Jun

2014-01-01

189

Modern synthetic efforts toward biologically active terpenes.  

PubMed

Terpenes represent one of the largest and most diverse classes of secondary metabolites, with over 55,000 members isolated to date. The terpene cyclase enzymes used in nature convert simple, linear hydrocarbon phosphates into an exotic array of chiral, carbocyclic skeletons. Further oxidation and rearrangement results in an almost endless number of conceivable structures. The enormous structural diversity presented by this class of natural products ensures a broad range of biological properties-ranging from anti-cancer and anti-malarial activities to tumor promotion and ion-channel binding. The marked structural differences of terpenes also largely thwart the development of any truly general strategies for their synthetic construction. This review focuses on synthetic strategies directed toward some of the most complex, biologically relevant terpenes prepared by total synthesis within the past decade. Of crucial importance are both the obstacles that modern synthetic chemists must confront when trying to construct such natural products and the key chemical transformations and strategies that have been developed to meet these challenges. PMID:17576427

Maimone, Thomas J; Baran, Phil S

2007-07-01

190

Copper activity in soil solutions of calcareous soils  

Microsoft Academic Search

Copper partitioning was studied in seven calcareous soils at moisture content corresponding to 1.2 times the field moisture content (soil water potential 7.84J kg?1). Copper retention was accompanied by the release in soil solution of Ca2+, Mg2+, Na+, and H+, and the total amount of these cations released was 0.8 to 1.09 times the amount of Cu sorbed (molc:molc). The

Alexander A. Ponizovsky; Herbert E. Allen; Amanda J. Ackerman

2007-01-01

191

Efficiency of soil organic and inorganic amendments on the remediation of a contaminated mine soil: II. Biological and ecotoxicological evaluation.  

PubMed

The feasibility of two organic materials (pig slurry and compost) in combination with hydrated lime for the remediation of a highly acidic trace elements (TEs) contaminated mine soil was assessed in a mesocosm experiment. The effects of the amendments on soil biochemical and ecotoxicological properties were evaluated and related with the main physicochemical characteristics of soil and soil solution. The original soil showed impaired basic ecological functions due to the high availability of TEs, its acidic pH and high salinity. The three amendments slightly reduced the direct and indirect soil toxicity to plants, invertebrates and microorganisms as a consequence of the TEs' mobility decrease in topsoil, reducing therefore the soil associated risks. The organic amendments, especially compost, thanks to the supply of essential nutrients, were able to improve soil health, as they stimulated plant growth and significantly increased enzyme activities related with the key nutrients in soil. Therefore, the use of compost or pig slurry, in combination with hydrated lime, decreased soil ecotoxicity and seems to be a suitable management strategy for the remediation of highly acidic TEs contaminated soils. PMID:24875876

Pardo, T; Clemente, R; Alvarenga, P; Bernal, M P

2014-07-01

192

NASA's Soil Moisture Active Passive (SMAP) observatory  

NASA Astrophysics Data System (ADS)

The Soil Moisture Active Passive (SMAP) mission, one of the first-tier missions recommended by the 2007 U.S. National Research Council Committee on Earth Science and Applications from Space, was confirmed in May 2012 by NASA to proceed into Implementation Phase (Phase C) with a planned launch in October 2014. SMAP will produce high-resolution and accurate global maps of soil moisture and its freeze/thaw state using data from a non-imaging synthetic aperture radar and a radiometer, both operating at L-band. Major challenges addressed by the observatory design include: (1) achieving global coverage every 2-3 days with a single observatory; (2) producing both high resolution and high accuracy soil moisture data, including through moderate vegetation; (3) using a mesh reflector antenna for L-band radiometry; (4) minimizing science data loss from terrestrial L-band radio frequency interference; (5) designing fault protection that also minimizes science data loss; (6) adapting planetary heritage avionics to meet SMAP's unique application and data volume needs; (7) ensuring observatory electromagnetic compatibility to avoid degrading science; (8) controlling a large spinning instrument with a small spacecraft; and (9) accommodating launch vehicle selection late in the observatory's development lifecycle.

Kellogg, K.; Thurman, S.; Edelstein, W.; Spencer, M.; Chen, Gun-Shing; Underwood, M.; Njoku, E.; Goodman, S.; Jai, Benhan

193

Biological responses of agricultural soils to fly-ash amendment.  

PubMed

The volume of solid waste produced in the world is increasing annually, and disposing of such wastes is a growing problem. Fly ash (FA) is a form of solid waste that is derived from the combustion of coal. Research has shown that fly ash may be disposed of by using it to amend agricultural soils. This review addresses the feasibility of amending agricultural field soils with fly ash for the purpose of improvings oil health and enhancing the production of agricultural crops. The current annual production of major coal combustion residues (CCRs) is estimated to be -600 million worldwide, of which about 500 million t (70-80%) is FA (Ahmaruzzaman 2010). More than 112 million t of FA is generated annually in India alone, and projections show that the production (including both FA and bottom ash) may exceed 170 million t per annum by 2015 (Pandey et al. 2009; Pandey and Singh 20 I 0). Managing this industrial by-product is a big challenge, because more is produced each year, and disposal poses a growing environmental problem.Studies on FA clearly shows that its application as an amendment to agricultural soils can significantly improve soil quality, and produce higher soil fertility. What FA application method is best and what level of application is appropriate for any one soil depends on the following factors: type of soil treated, crop grown, the prevailing agro climatic condition and the character of the FA used. Although utilizing FA in agricultural soils may help address solid waste disposal problems and may enhance agricultural production, its use has potential adverse effects also. In particular, using it in agriculture may enhance amounts of radionuclides and heavy metals that reach soils, and may therefore increase organism exposures in some instances. PMID:24984834

Singh, Rajeev Pratap; Sharma, Bhavisha; Sarkar, Abhijit; Sengupta, Chandan; Singh, Pooja; Ibrahim, Mahamad Hakimi

2014-01-01

194

Natural physical and biological processes compromise the long-term performance of compacted soil caps  

SciTech Connect

Compacted soil barriers are components of essentially all caps placed on closed waste disposal sites. The intended functions of soil barriers in waste facility caps include restricting infiltration of water and release of gases and vapors, either independently or in combination with synthetic membrane barriers, and protecting other manmade or natural barrier components. Review of the performance of installed soil barriers and of natural processes affecting their performance indicates that compacted soil caps may function effectively for relatively short periods (years to decades), but natural physical and biological processes can be expected to cause them to fail in the long term (decades to centuries). This paper addresses natural physical and biological processes that compromise the performance of compacted soil caps and suggests measures that may reduce the adverse consequences of these natural failure mechanisms.

Smith, E.D.

1995-12-01

195

Soil biology and warming play a key role in the release of ‘old C’ from organic soils  

Microsoft Academic Search

A radiocarbon approach was used to investigate the roles of temperature and soil fauna activity in the turnover of ‘old’ non-labile carbon in a peatland ecosystem. We investigated the impacts of enchytraeids on carbon turnover in two different soil layers, with different incorporation of the ‘bomb’ peak, when incubated at two different temperatures. Results showed that, in agreement with previous

Maria Jesus Iglesias Briones; Mark H. Garnett; Phil Ineson

2010-01-01

196

Biological interactions between soil saprotrophic fungi and Ascaris suum eggs.  

PubMed

The in vitro effect of saprotrophic soil fungi on the embryonic development of Ascaris suum was evaluated. The fungi tested were Aspergillus fumigatus, Aspergillus terreus, Penicillium citrinum, Penicillium expansum, Fusarium oxysporum and Trichothecium roseum, isolated from children's recreation areas in the city of Lodz (Poland). Each species was co-cultured with A. suum egg suspension (6 × 10(3)eggs/ml) at 25 ± 2°C for 60 days. Each day, 100 eggs were randomly collected and their developmental stage was classified macroscopically. Additionally, at days 4, 7, 14, 28, 42 and 60 of incubation, the viability and the percentage of eggs with morphological altered embryo/larva were determined in each sample. Microscopic examination revealed that exposure of eggs to the mycelium of examined fungi inhibited embryogenesis of A. suum. All control culture eggs reached L2 larval stage after 26 days of incubation, while the experimental cultures did so after 32-51 days, depending on the fungal species. Three species were found to exhibit very high inhibitory activity on A. suum egg development: A. terreus, P. expansum and F. oxysporum. Embryopathies and non-viable embryos/larvae were observed significantly more frequently in the eggs co-cultured with fungal species than in control cultures. The fungus-exposed eggs revealed morphological alternations in the early zygotic cleavage, blastula, gastrula and larval stages. After 60 days of incubation with mycelia of P. expansum, A. terreus and F. oxysporum, the mortality of the larvae reached 55.3-60.3%. P. expansum and F. oxysporum showed hyphal penetration and internal egg colonization of A. suum eggs. PMID:23534981

Blaszkowska, Joanna; Wojcik, Anna; Kurnatowski, Piotr; Szwabe, Katarzyna

2013-09-23

197

Impact of Long-Term Forest Enrichment Planting on the Biological Status of Soil in a Deforested Dipterocarp Forest in Perak, Malaysia  

PubMed Central

Deforestation leads to the deterioration of soil fertility which occurs rapidly under tropical climates. Forest rehabilitation is one of the approaches to restore soil fertility and increase the productivity of degraded areas. The objective of this study was to evaluate and compare soil biological properties under enrichment planting and secondary forests at Tapah Hill Forest Reserve, Perak after 42 years of planting. Both areas were excessively logged in the 1950s and left idle without any appropriate forest management until 1968 when rehabilitation program was initiated. Six subplots (20?m × 20?m) were established within each enrichment planting (F1) and secondary forest (F2) plots, after which soil was sampled at depths of 0–15?cm (topsoil) and 15–30?cm (subsoil). Results showed that total mean microbial enzymatic activity, as well as biomass C and N content, was significantly higher in F1 compared to F2. The results, despite sample variability, suggest that the rehabilitation program improves the soil biological activities where high rate of soil organic matter, organic C, N, suitable soil acidity range, and abundance of forest litter is believed to be the predisposing factor promoting higher population of microbial in F1 as compared to F2. In conclusion total microbial enzymatic activity, biomass C and biomass N evaluation were higher in enrichment planting plot compared to secondary forest. After 42 years of planting, rehabilitation or enrichment planting helps to restore the productivity of planted forest in terms of biological parameters. PMID:22606055

Karam, D. S.; Arifin, A.; Radziah, O.; Shamshuddin, J.; Majid, N. M.; Hazandy, A. H.; Zahari, I.; Nor Halizah, A. H.; Rui, T. X.

2012-01-01

198

Neutron-activation analysis of chlorine-containing pesticides in soils and tobaccos  

Microsoft Academic Search

From second national conference on uses of radioisotopes and ; .ionizing radiation in biology and agriculture; Softa, Bulgaria (25 Nov 1972). ; A nondestructive method was developed for determining the total residue levels of ; chlorine-containing pesticides in soils and farm produce. For accurate ; determination of organically bound chlorine in the different ; objects, preliminary inorganic extraction, neutron activation,

T. Dimchev; Kh. Gunchev

1972-01-01

199

The influence of elevation, shrubspecies, and biological soil crust on fertile islands in the Mojave Desert, USA  

Microsoft Academic Search

We quantified soil nutrients and biological crust cover (bryophytes and lichens) under the canopies of three species of Mojave Desert shrubs and in interspaces between shrubs at three elevations to determine the effects of shrubspecies, soil crust, and elevation on islands of soil fertility. Means of pH, organic matter, total Kjeldahl nitrogen, nitrogen mineralization, and gravimetric soil moisture are significantly

D. B. Thompson; L. R. Walker; F. H. Landau; L. R. Stark

200

Assessment of the ecological security of immobilized enzyme remediation process with biological indicators of soil health.  

PubMed

This study used the enzymes extracted from an atrazine-degrading strain, Arthrobacter sp. DNS10, which had been immobilized by sodium alginate to rehabilitate atrazine-polluted soil. Meanwhile, a range of biological indices were selected to assess the ecological health of contaminated soils and the ecological security of this bioremediation method. The results showed that there was no atrazine detected in soil samples after 28 days in EN+AT (the soil containing atrazine and immobilized enzyme) treatment. However, the residual atrazine concentration of the sample in AT (the soil containing atrazine only) treatment was about 5.02 ± 0.93 mg kg(-1). These results suggest that the immobilized enzyme exhibits an excellent ability in atrazine degradation. Furthermore, the immobilized enzyme could relieve soil microbial biomass carbon and soil microbial respiration intensity to 772.33 ± 34.93 mg C kg(-1) and 5.01 ± 0.17 mg CO(2) g(-1) soil h(-1), respectively. The results of the polymerase chain reaction-degeneration gradient gel electrophoresis experiment indicated that the immobilized enzyme also could make the Shannon-Wiener index and evenness index of the soil sample increase from 1.02 and 0.74 to 1.51 and 0.84, respectively. These results indicated that the immobilized enzymes not only could relieve the impact from atrazine on the soil, but also revealed that the immobilized enzymes did no significant harm on the soil ecological health. PMID:23468306

Zhang, Ying; Dong, Xiaonan; Jiang, Zhao; Cao, Bo; Ge, Shijie; Hu, Miao

2013-08-01

201

Changes and recovery of soil bacterial communities influenced by biological soil disinfestation as compared with chloropicrin-treatment  

PubMed Central

Soil bacterial composition, as influenced by biological soil disinfestation (BSD) associated with biomass incorporation was investigated to observe the effects of the treatment on the changes and recovery of the microbial community in a commercial greenhouse setting. Chloropicrin (CP) was also used for soil disinfestation to compare with the effects of BSD. The fusarium wilt disease incidence of spinach cultivated in the BSD- and CP-treated plots was reduced as compared with that in the untreated control plots, showing effectiveness of both methods to suppress the disease. The clone library analyses based on 16S rRNA gene sequences showed that members of the Firmicutes became dominant in the soil bacterial community after the BSD-treatment. Clone groups related to the species in the class Clostridia, such as Clostridium saccharobutylicum, Clostridium tetanomorphum, Clostridium cylindrosporum, Oxobacter pfennigii, etc., as well as Bacillus niacini in the class Bacilli were recognized as the most dominant members in the community. For the CP-treated soil, clones affiliated with the Bacilli related to acid-tolerant or thermophilic bacteria such as Tuberibacillus calidus, Sporolactobacillus laevolacticus, Pullulanibacillus naganoensis, Alicyclobacillus pomorum, etc. were detected as the major groups. The clone library analysis for the soil samples collected after spinach cultivation revealed that most of bacterial groups present in the original soil belonging to the phyla Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes, Planctomycetes, TM7, etc. were recovered in the BSD-treated soil. For the CP-treated soil, the recovery of the bacterial groups belonging to the above phyla was also noted, but some major clone groups recognized in the original soil did not recover fully. PMID:23958081

2013-01-01

202

Soil zymography - A novel technique for mapping enzyme activity in the rhizosphere  

NASA Astrophysics Data System (ADS)

The effect plant roots on microbial activity in soil at the millimeter scale is poorly understood. One reason for this is that spatially explicit methods for the study of microbial activity in soil are limited. Here we present a quantitative in situ technique for mapping the distribution of exoenzymes in soil along with some results about the effects of roots on exoenzyme activity in soil. In the first study we showed that both acid and alkaline phosphatase activity were up to 5.4-times larger in the rhizosphere of Lupinus albus than in the bulk soil. While acid phosphatase activity (produced by roots and microorganisms) was closely associated with roots, alkaline phosphatase activity (produced only by microorganisms) was more widely distributed, leading to a 2.5-times larger area of activity of alkaline than of acid phosphatase. These results indicate a spatial differentiation of different ecophysiological groups of organic phosphorus mineralizing organisms in the rhizosphere which might alleviate a potential competition for phosphorus between them. In a second study cellulase, chitinase and phosphatase activities were analyzed in the presence of living Lupinus polyphyllus roots and dead/dying roots (in the same soils 10, 20 and 30 days after cutting the L. polyphyllus shoots). The activity of all three enzymes was 9.0 to 13.9-times higher at the living roots compared to the bulk soil. Microhotspots of cellulase, chitinase and phosphatase activity in the soil were found up to 60 mm away from the living roots. 10 days after shoot cutting, the areas of high activities of cellulase and phosphatase activity were extend up to 55 mm away from the next root, while the extension of the area of chitinase activity did not change significantly. At the root, cellulase and chitinase activity increased first at the root tips after shoot cutting and showed maximal activity 20 days after shoot cutting. The number and activity of microhotspots of chitinase activity was maximal 10 days after shoot cutting and decreased thereafter. In conclusion, the study showed that fresh root detritus stimulates enzyme activities much stronger than living roots, probably because of the high pulse input of C and N from dying roots compared to slow continuous release of rhizodeposits. Taken together, soil zymography is a very promising novel technique to gain insights the effects of roots on the spatial and temporal dynamic of exoenzyme activity in soil. References Spohn, M., Carminati, A., Kuzyakov, Y. (2013). Zymography - A novel in situ method for mapping distribution of enzyme activity in soil. Soil Biology and Biochemistry 58, 275-280. Spohn, M., Kuzyakov, Y. (2013): Distribution of microbial- and root- derived phosphatase activities in the rhizosphere depending on P availability and C allocation - Coupling soil zymography with 14C imaging. Soil Biology and Biochemistry 67, 106-113. Spohn, M., Kuzyakov, Y. (accepted): Spatial and temporal dynamics of hotspots of enzyme activity as affected by living and dead roots - A soil zymography analysis. Plant and Soil

Spohn, Marie

2014-05-01

203

Accommodating Students with Disabilities in Soil Science Activities  

ERIC Educational Resources Information Center

Soil science education is lacking in terms of accommodations for persons with disabilities. Individuals with disabilities are often excluded from soil science activities in school, and from soil science careers. GLOBE (Global Learning Observations to Benefit the Environment) is a worldwide, hands-on primary and secondary school-based education and…

Langley-Turnbaugh, S. J.; Murphy, Kate; Levin, E.

2004-01-01

204

Biological activity and environmental impact of anionic surfactants  

Microsoft Academic Search

The newest results concerning the biological activity and environmental fate of anionic surfactants are collected and critically evaluated. The chemical and physicochemical parameters related to the biological activity and the field of application are briefly discussed. Examples on the effect of anionic surfactants on the cell membranes, on the activity of enzymes, on the binding to various proteins and to

Tibor Cserháti; Esther Forgács; Gyula Oros

2002-01-01

205

BIOLOGICALLY-MEDIATED REMOVAL AND RECOVERY OF PLUTONIUM FROM CONTAMINATED SOIL  

SciTech Connect

An innovative biological treatment technology successfully reduced plutonium concentration in soil from the Nevada Test Site (NTS) by over 80%. The final volume of plutonium-contaminated material that required disposal was reduced by over 90%. These results, achieved by an independent testing laboratory, confirm the results reported previously using NTS soil. In the previous test a 2530-gram sample of soil (350 to 400 pCi/g Pu) resulted in production of 131 grams of sludge (6,320 pCi/ g Pu) and a treated soil containing 72 pCi/g of Pu. The technology is based on the biological acidification of the soil and subsequent removal of the plutonium and other dissolved metals by a low volume, low energy water leaching process. The leachate is treated in a sulfate-reducing bioreactor to precipitate the metals as metal sulfides. Water may be recycled as process water or disposed since the treatment process removes over 99% of the dissolved metals including plutonium from the water. The plutonium is contained as a stable sludge that can be containerized for final disposal. Full-scale process costs have been developed which employ widely used treatment technologies such as aerated soil piles (biopiles) and bioreactors. The process costs were less than $10 per cubic foot, which were 40 to 50% lower than the baseline costs for the treatment of the NTS soil. The equipment and materials for water and sludge treatment and soil handling are commercially available.

Jerger, Douglas E., Ph.D.,; Alperin, Edward S., QEP,; Holmes, Robert G., Ph.D.

2003-02-27

206

Effect of Calcium Content on Soil Stabilisation with Alkaline Activation  

Microsoft Academic Search

This paper in concerned with the role of calcium content in fly ash used to stabilise soft soils through alkaline activation with sodium-based alkaline activators. A 10 molal sodium hydroxide solution was used to activate fly ash at solution: ash ratios of 2: 1 and 4: 1, and at a solution: (soil + ash) ratio of 0.40. Fly ash type

Nuno Cristelo; Stephanie Glendinning; Lisete Fernandes; Amândio Teixeira Pinto

207

Community Level Physiological Profiles (CLPP), Characterization and Microbial Activity of Soil Amended with Dairy Sewage Sludge  

PubMed Central

The aim of the present work was to assess the influence of organic amendment applications compared to mineral fertilization on soil microbial activity and functional diversity. The field experiment was set up on a soil classified as an Eutric Cambisol developed from loess (South-East Poland). Two doses of both dairy sewage sludge (20 Mg·ha?1 and 26 Mg·ha?1) and of mineral fertilizers containing the same amount of nutrients were applied. The same soil without any amendment was used as a control. The soil under undisturbed native vegetation was also included in the study as a representative background sample. The functional diversity (catabolic potential) was assessed using such indices as Average Well Color Development (AWCD), Richness (R) and Shannon–Weaver index (H). These indices were calculated, following the community level physiological profiling (CLPP) using Biolog Eco Plates. Soil dehydrogenase and respiratory activity were also evaluated. The indices were sensitive enough to reveal changes in community level physiological profiles due to treatment effects. It was shown that dairy sewage amended soil was characterized by greater AWCD, R, H and dehydrogenase and respiratory activity as compared to control or mineral fertilized soil. Analysis of variance (ANOVA) and principal component analysis (PCA) were used to depict the differences of the soil bacterial functional diversity between the treatments. PMID:22737006

Fr?c, Magdalena; Oszust, Karolina; Lipiec, Jerzy

2012-01-01

208

Community level physiological profiles (CLPP), characterization and microbial activity of soil amended with dairy sewage sludge.  

PubMed

The aim of the present work was to assess the influence of organic amendment applications compared to mineral fertilization on soil microbial activity and functional diversity. The field experiment was set up on a soil classified as an Eutric Cambisol developed from loess (South-East Poland). Two doses of both dairy sewage sludge (20 Mg·ha(-1) and 26 Mg·ha(-1)) and of mineral fertilizers containing the same amount of nutrients were applied. The same soil without any amendment was used as a control. The soil under undisturbed native vegetation was also included in the study as a representative background sample. The functional diversity (catabolic potential) was assessed using such indices as Average Well Color Development (AWCD), Richness (R) and Shannon-Weaver index (H). These indices were calculated, following the community level physiological profiling (CLPP) using Biolog Eco Plates. Soil dehydrogenase and respiratory activity were also evaluated. The indices were sensitive enough to reveal changes in community level physiological profiles due to treatment effects. It was shown that dairy sewage amended soil was characterized by greater AWCD, R, H and dehydrogenase and respiratory activity as compared to control or mineral fertilized soil. Analysis of variance (ANOVA) and principal component analysis (PCA) were used to depict the differences of the soil bacterial functional diversity between the treatments. PMID:22737006

Fr?c, Magdalena; Oszust, Karolina; Lipiec, Jerzy

2012-01-01

209

Ecology and biology of microfungi from Antarctic rocks and soils  

Microsoft Academic Search

Cryptoendolithic microbial communities, living in porous sandstone rocks in the McMurdo Dry Valleys (Ross Desert) of Southern Victoria Land, Antarctica, were found within weathered pegmatite rocks in Northern Victoria Land, and the first endemic Antarctic fungal genus Friedmanniomyces endolithicus anam.?gen. and sp. nov. was isolated from this community. Selected microfungi from these communities and from soil were examined for the

Silvano Onofri; Massimiliano Fenice; Anna Rita Cicalini; Solveig Tosi; Anna Magrino; Sabina Pagano; Laura Selbmann; Laura Zucconi; Helen S. Vishniac; E. Imre Friedmann

2000-01-01

210

The biological detoxication of hormone herbicides in soil  

Microsoft Academic Search

Summary (1) The results of experiments on the continuous perfusion of aerated solutions of the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D), 2, Methyl-4, chlorophenoxyacetic acid (MCPA) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) through garden soil indicate that the kinetics of their breakdown are essentially similar.

L. J. Audus

1951-01-01

211

Proteomic profiling: a novel approach to understanding the biological causes of soil water repellency  

NASA Astrophysics Data System (ADS)

Soil water repellency is a common phenomenon affecting a wide range of soil and land use types in different climates and is considered "the norm rather than the exception with its degree being variable". In all but the most severe cases, soil water repellency is transient with soils wetting eventually after prolonged wet weather and returning, when soil moisture content falls below the critical value. Despite the far-reaching environmental and (agro-)economic consequences, the fundamental biological causes of soil water repellency and its transient behaviour remain poorly understood. It is widely accepted that soil water repellency is caused by organic compounds coating soil particle surfaces. This reduces the particle's surface tension to values lower than that of water, which, as a net effect, inhibits the intrusion of liquid water into the soil pore space. Microbial as well as plant-derived substances have been implicated as sources of these organic materials, while some microbes have also been identified as degraders and/or emulsifiers of hydrophobic compounds. Common hydrophobic compounds and metabolites (e.g. alkanes and fatty acids) have been isolated from both wettable and water repellent soils in similar amounts indicating that their relevance is ambiguous. Even greater uncertainty exists about the role of soil micro-organisms in the development, reduction and temporal variability of soil water repellency. Importantly, certain filamentous fungi and actinomycete bacteria are able to render their hydrophilic cell surface hydrophobic, for example, during spore formation and hyphal foraging through air-containing pores in soil, by producing extracellular hydrophobic proteins. Beyond their own cell surface, the extracellular proteins can form highly recalcitrant hydrophobic surfaces on the hydrophilic side of amphiphilic, i.e. air-water or soil particle, interfaces. Remarkably, the proteins from fungi can also adhere to hydrophobic surfaces under drying conditions rendering them hydrophilic. The dynamics of production of these proteins and the formation of these hydrophobic protein surfaces in soils are not known. Other, yet unknown, proteins may also contribute to development, reduction and temporal variability of soil water repellency. Here we present the first steps of a new NERC funded project aimed at exploring the relationship between the presence and/or absence of (hydrophobic) protein and soil water repellency. It involves isolation and characterisation of hydrophobic protein and the temporal metaproteomic profiles in UK grassland and dune soils with varying degrees of water repellency. This contributes to identifying the proteomic dynamics, which may influence soil hydrology and structure, and ultimately the ability of soils to absorb water, support biomass growth, store carbon, and to capture and degrade pollutants.

van Keulen, Geertje; Doerr, Stefan H.; Urbanek, Emilia; Jones, Alun; Dudley, Ed

2010-05-01

212

Misidentification of soil bacteria by fatty acid methyl ester (FAME) and BIOLOG analyses  

Microsoft Academic Search

Fatty acid methyl ester (FAME) analysis is commonly used by soil scientists as a sole method for identifying soil bacteria.\\u000a We observed discrepancies with this method for identifying certain species of bacteria. Therefore, we used carbon substrate\\u000a oxidation patterns (BIOLOG) and some simple physical and chemical tests to determine the extent of these discrepancies. Identification\\u000a with FAME profiles gave false

N. Oka; P. G. Hartel; O. Finlay-Moore; J. Gagliardi; D. A. Zuberer; J. J. Fuhrmann; J. S. Angle; H. D. Skipper

2000-01-01

213

Nitrogen cycling in desert biological soil crusts across biogeographic regions in the Southwestern United States  

Microsoft Academic Search

Biological soil crusts (BSCs) are thought to be important in the fertility of arid lands as gateways for carbon (C) and nitrogen\\u000a (N). Studies on the Colorado Plateau have shown that an incomplete internal N cycle operates in BSCs that results in significant\\u000a exports of dissolved organic N, ammonia and nitrate into the bulk soil through percolating water, thus mechanistically

Sarah L. StraussThomas; Thomas A. Day; Ferran Garcia-Pichel

214

Biogeosystem technique as a method to overcome the Biological and Environmental Hazards of modern Agricultural, Irrigational and Technological Activities  

NASA Astrophysics Data System (ADS)

Modern challenge for humanity is to replace the paradigm of nature use and overcome environmental hazards of agronomy, irrigation, industry, and other human activities in biosphere. It is utterly reasonable to stop dividing biosphere on shares - the human habitat and the environment. In the 21st century it is an outdated anthropocentrism. Contradicting himself to biosphere Humankind has the problems. The new paradigm of biosphere control by methods of Biogeosystem technique is on agenda of Humankind. Key directions of Biogeosystem technique. Tillage. Single rotary milling 20…30-50…60 sm soil layer optimizes the evolution and environment of soil, creates a favorable conditions for the rhizosphere, increases the biological productivity of biosphere by 30-50% compared to the standard agricultural practices for the period up to 40 years. Recycle material. Recycling of mineral and organic substances in soil layer of 20…30-50…60 sm in rotary milling soil processing provides wastes clean return to biosphere. Direct intrasoil substances synthesis. Environmentally friendly robot wasteless nanotechnology provides direct substances synthesis, including fertilizers, inside the soil. It eliminates the prerequisites of the wastes formation under standard industrial technologies. Selective substance's extraction from soil. Electrochemical robotic nanotechnology provides selective substances extraction from soil. The technology provides recovery, collection and subsequent safe industrial use of extracted substances out of landscape. Saving fresh water. An important task is to save fresh water in biosphere. Irrigation spends water 4-5 times more of biological requirements of plants, leads to degradation of soil and landscape. The intrasoil pulse continuous-discrete paradigm of irrigation is proposed. It provides the soil and landscape conservation, increases the biological productivity, save the fresh water up to 10-20 times. The subsurface soil rotary processing and intrasoil pulsed continuous-discrete irrigation provide environmentally safe disposal of municipal, industrial, biological and agricultural wastes. Hazardous chemical and biological agents are under the soil surface. It provided a medical and veterinary safety of environment. Biogeosystem technic controls the equilibria in the soil and soil solution, prevents excessive mineralization of organic matter in the surface layers of soil. Simultaneously a soil chemical reduction excluded, biological substance do not degrade to gases. Products of organic matter decomposition are directed to the food chain, 100% waste recycling is obtained. Biogeosystems technique allows producing more biological products hence to recycle excessive amount of man-made CO2 and other substances. Biogeosystems technique increases the rate of photosynthesis of the biosphere, the degree of air ionization. This enhances the formation of rains over land, ensures stability of the ionosphere, magnetosphere and atmosphere of Earth. The nowadays technologies allow applying technical solutions based on Biogeosystem technique, there is unique opportunity to accelerate the noosphere new technological platform.

Kalinitchenko, Valery; Batukaev, Abdulmalik; Zinchenko, Vladimir; Zarmaev, Ali; Magomadov, Ali; Chernenko, Vladimir; Startsev, Viktor; Bakoev, Serojdin; Dikaev, Zaurbek

2014-05-01

215

Soil surface disturbances in cold deserts: effects on nitrogenase activity in cyanobacterial-lichen soil crusts  

Microsoft Academic Search

Cyanobacterial-lichen soil crusts can be a dominant source of nitrogen for cold-desert ecosystems. Effects of surface disturbance from footprints, bike and vehicle tracks on the nitrogenase activity in these crusts was investigated. Surface disturbances reduced nitrogenase activity by 30–100%. Crusts dominated by the cyanobacterium Microcoleus vaginatus on sandy soils were the most susceptible to disruption; crusts on gypsiferous soils were

J. Belnap

1996-01-01

216

Microbial activity in response to water-filled pore space of variably eroded southern Piedmont soils  

Microsoft Academic Search

Potential C and N mineralization and soil microbial biomass C (SMBC) are soil biological properties important in understanding nutrient and organic matter dynamics. Knowledge of soil water content at a matric potential near field capacity is needed to determine these biological properties. The objective of this study was to examine whether adjustment of soil water content to a common level

A. J. Franzluebbers

1999-01-01

217

Effect of untreated sewage effluent irrigation on heavy metal content, microbial population and enzymatic activities of soils in Aligarh.  

PubMed

The study pertains to the impact of domestic and industrial sewage water irrigation on the chemical, biological and enzymatic activities in alluvial soils of Aligarh District. Results showed that soil enzymatic [dehydogenase (DHA), acid and alkaline phosphatase, urease and catalase] activities in the soils increased up to 14 days of incubation and thereafter inhibited significantly. The enzymatic activity were in the order sewage effluent > partial sewage effluent > ground water irrigated soils. Increase in soil enzymatic activities up to 2nd week of incubation was due to decomposition of organic matter. Maximum inhibition of enzymatic activities, after 14 days of incubation were found in sewage effluent irrigated soils and minimum in ground water irrigated soils. Similar trend was also seen for microbial population. Soil enzymatic activities and microbial population were significantly and positively correlated with soil organic matter. Results also indicated that the microbial population and enzymatic activities in sewage irrigated soils decreased continually with irrigation period. The average concentration of total heavy metals in sewage irrigated soils and partial sewage irrigated soils increased and was 3 and 2 times higher for Zn; 4.5 and 1.7 times higher for Cu; 3.8 and 2.4 times higher for Cr; 5.7 and 3.5 times higher for Pb; 3.5 and 2.2 times higher for Cd and 2.7 and 2.0 times higher for Ni respectively than that of ground water irrigated soils. Results also showed that though total heavy metals concentration increased with period of sewage irrigation but the concentration of diethylene triamine pentaacetic acid (DTPA) extractable heavy metals in partial sewage irrigated and sewage irrigated soils remained almost same, which might be due to deposition of heavy metals in crops grown on the soils. PMID:25004747

Bansal, O P; Singh, Gajraj; Katiyar, Pragati

2014-07-01

218

Near infrared spectra are more sensitive to land use changes than physical, chemical and biological soil properties  

NASA Astrophysics Data System (ADS)

We studied the sensibility of the near infrared spectra (NIR) of soils to the changes caused by land use, and we compared with the sensibility of different sets of physical, chemical and biological soil properties. For this purpose, we selected three land uses, constituted by forest, almond trees orchards, and orchards abandoned between 10 and 15 years previously to sampling. Sampling was carried out in four different locations from the province of Alicante (SE Spain). We used discriminant analysis (DA) using different sets of soil properties. The different sets tested in this study using DA were: (1) physical and chemical properties (organic carbon, total nitrogen, available phosphorus, pH, electrical conductivity, cation exchange capacity, aggregate stability, water holding capacity, and available Ca, Mg, K and Na), (2) biochemical properties (microbial biomass carbon, basal respiration and urease, phosphatase and ?-glucosidase activities), (3) phospholipids fatty acids (PLFAs), (4) physical, chemical and biochemical properties (all properties of the previous sets), and (5) the NIR spectra of soils (scores of the principal components). In general, all sets of properties were sensible to land use. This was observed in the DAs by the separation (more or less clear) of samples in groups defined by land use (irrespective of site). The worst results were obtained using soil physical and chemical properties. The combination of physical, chemical and biological properties enhanced the separation of samples in groups, indicating higher sensibility. It is accepted than combination of properties of different nature is more effective to evaluate the soil quality. The microbial community structure (PLFAs) was highly sensible to the land use, grouping correctly the 100% of the samples according with the land use. The NIR spectra were also sensitive to land use. The scores of the first 5 components, which explained 99.97% of the variance, grouped correctly the 85% of the soil samples by land use, but were unable to group correctly the 100% of the samples. Surprisingly, when the scarce variance presents in components 5 to 40 was also used, the 100% of the samples were grouped by land use, as it was observed with PLFAs. But PLFAs analysis is expensive and time-consuming (some weeks). In contrast, only some minutes are needed for the obtainment of the NIR spectra. Additionally, no chemicals are need, decreasing the costs. The NIR spectrum of a soil contains relevant information about physical, chemical and biochemical properties. NIR spectrum could be considered as an integrated vision of soil quality, and as consequence offers an integrated vision of perturbations. Thus, NIR spectroscopy could be used as tool to monitoring soil quality in large areas. Acknowledgements: Authors acknowledge to "Bancaja-UMH" for the financial support of the project "NIRPRO"

Guerrero, C.; Zornoza, R.; Mataix-Solera, J.; Mataix-Beneyto, J.; Scow, K.

2009-04-01

219

Biological Remediation of Soil: An Overview of Global Market and Available Technologies  

NASA Astrophysics Data System (ADS)

Due to a wide range of industrial and agricultural activities, a high number of chemical contaminants is released into the environment, causing a significant concern regarding potential toxicity, carcinogenicity, and potential for bioaccumulation in living systems of various chemicals in soil. Although microbial activity in soil accounts for most of the degradation of organic contaminants, chemical and physical mechanisms can also provide significant transformation pathways for these compounds. The specific remediation processes that have been applied to clean up contaminated sites include natural attenuation, landfarming, biopiling or composting, contained slurry bioreactor, bioventing, soil vapor extraction, thermal desorption, incineration, soil washing and land filling (USEPA 2004).

Singh, Ajay; Kuhad, Ramesh C.; Ward, Owen P.

220

PHOSPHOLIPID AND FDA ACTIVITY MEASUREMENTS ADAPTED TO BIOLOGICAL GAC  

EPA Science Inventory

Established microbial ecology analytical techniques for measuring the quantity and activity of bacteria were examined for use on biological granular activated carbon (GAC). ctivity was determined using the fluorescein diacetate (FDA) assay. he assay was tested and accordingly cor...

221

Multifunctional and biologically active matrices from multicomponent polymeric solutions  

NASA Technical Reports Server (NTRS)

A functionalized electrospun matrix for the controlled-release of biologically active agents, such as growth factors, is presented. The functionalized matrix comprises a matrix polymer, a compatibilizing polymer and a biomolecule or other small functioning molecule. In certain aspects the electrospun polymer fibers comprise at least one biologically active molecule functionalized with low molecular weight heparin.

Kiick, Kristi L. (Inventor); Yamaguchi, Nori (Inventor); Rabolt, John (Inventor); Casper, Cheryl (Inventor)

2012-01-01

222

Synthesis, reactivity and biological activity of 5-alkoxymethyluracil analogues  

PubMed Central

Summary This review article summarizes the results of a long-term investigation of 5-alkoxymethyluracil analogues and is aimed, in particular, at methods of syntheses. Most of the presented compounds were synthesized in order to evaluate their biological activity, therefore, a brief survey of biological activity, especially antiviral, cytotoxic and antibacterial, is also reported. PMID:21804865

Brulikova, Lucie

2011-01-01

223

Biological activity of essential oils and their constituents  

Microsoft Academic Search

Recent work in the field of biologically active, essential oils is reviewed. Essential oil extraction methods that are covered include cold pressing, extraction with other essential oils, steam distillation, solvent extraction, supercritical fluid extraction, and solid phase extraction. Separation methods for the isolation of individual constituents that are covered include GC, LC, and distillation. Biological activities of essential oils and

Andrew T. Lupo; John W. Chinn; Raphael K. L. Kang

2000-01-01

224

Evaluation of the co-application of fly ash and sewage sludge on soil biological and biochemical quality.  

PubMed

Disposal of sewage sludge (SS) and fly ash (FA) is a multifaceted problem, which can affect environmental quality. FA has the potential to stabilize SS by reducing metal availability and making the SS suitable for application in the agricultural sector. An experiment was performed to evaluate soil biological quality changes with the combined amendment of SS and FA (fluidized bed combustion ash (FBCA) and lignite fly ash (LFA)). SS was amended with 0, 10, 30, 50 and 100%, (w/w) of FA, and then the FA-SS mixtures were incubated with red soil at 1:1 (v/v). Soil quality parameters such as pH, electrical conductivity, N, soil enzyme activities such as dehydrogenase (DHA), urease (URE), and catalase (CAT), and microbial biomass carbon (MBC) were evaluated at 20, 30, and 60 days of incubation, pH and EC increased with FA-SS dose; however, N decreased. DHA and URE were found to be increased with 10% LFA amendment; thereafter it decreased. However, URE increased up to 30% of FBCA. CAT and MBC increased with both FA amendments, even up to addition of 50% FA. Bioavailable Zn, Cu, and Co contents were decreased by the addition of FA. Principal component analysis showed that pH is the most influential factor. MBC appears to be a sensitive soil indicator for the effects that result from the addition of FA-SS. Phytotoxicity studies with Zea mays showed optimum performance at 30% FA. Addition of 10-30% FBCA or LFA to SS has a positive advantage on soil biological quality. PMID:22720414

Masto, Reginald E; Sunar, Kapil K; Sengupta, Taniya; Ram, Lal C; Rout, T K; Selvi, Vetrivel A; George, Joshy; Sinha, Awadhesh K

2012-01-01

225

Managing Our Grandchildren's Forests: The Role of Soil Biology and Soil Ecology1  

E-print Network

matter and energy, water and nutrients, organic matter, and gases. Soils within forest ecosystems support roots, water, and nutrients; store and transmit organic matter; and are habitats for a fantastic array on soil organisms and organic matter decomposition processes. Effects are site- and cutting system

Standiford, Richard B.

226

The Soil Moisture Active Passive (SMAP) Applications Activity  

NASA Technical Reports Server (NTRS)

The Soil Moisture Active Passive (SMAP) mission is one of the first-tier satellite missions recommended by the U.S. National Research Council Committee on Earth Science and Applications from Space. The SMAP mission 1 is under development by NASA and is scheduled for launch late in 2014. The SMAP measurements will allow global and high-resolution mapping of soil moisture and its freeze/thaw state at resolutions from 3-40 km. These measurements will have high value for a wide range of environmental applications that underpin many weather-related decisions including drought and flood guidance, agricultural productivity estimation, weather forecasting, climate predictions, and human health risk. In 2007, NASA was tasked by The National Academies to ensure that emerging scientific knowledge is actively applied to obtain societal benefits by broadening community participation and improving means for use of information. SMAP is one of the first missions to come out of this new charge, and its Applications Plan forms the basis for ensuring its commitment to its users. The purpose of this paper is to outline the methods and approaches of the SMAP applications activity, which is designed to increase and sustain the interaction between users and scientists involved in mission development.

Brown, Molly E.; Moran, Susan; Escobar, Vanessa; Entekhabi, Dara; O'Neill, Peggy; Njoku, Eni

2011-01-01

227

Conservation tillage, optimal water and organic nutrient supply enhance soil microbial activities during wheat (Triticum Aestivum L.) cultivation  

PubMed Central

The field experiments were conducted on sandy loam soil at New Delhi, during 2007 and 2008 to investigate the effect of conservation tillage, irrigation regimes (sub-optimal, optimal and supra-optimal water regimes), and integrated nutrient management (INM) practices on soil biological parameters in wheat cultivation. The conservation tillage soils has shown significant (p<0.05) increase in soil respiration (81.1%), soil microbial biomass carbon (SMBC) (104%) and soil dehydrogenase (DH) (59.2%) compared to the conventional tillage soil. Optimum water supply (3-irrigations) enhanced soil respiration over sub-optimum and supra-optimum irrigations by 13.32% and 79% respectively. Soil dehydrogenase (DH) activity in optimum water regime has also increased by 23.33% and 8.18% respectively over the other two irrigation regimes. Similarly, SMBC has also increased by 12.14% and 27.17% respectively in soil with optimum water supply compared to that of sub-optimum and supra-optimum water regime fields. The maximum increase in soil microbial activities is found when sole organic source (50% Farm Yard Manure+25% biofertilizer+25% Green Manure) has been used in combination with the conservation tillage and the optimum water supply. Study demonstrated that microbial activity could be regulated by tillage, water and nitrogen management in the soil in a sustainable manner. PMID:24031665

Sharma, Pankaj; Singh, Geeta; Singh, Rana P.

2011-01-01

228

Metal-accumulating plants: The biological resource and its commercial exploitation is soil clean-up technology  

SciTech Connect

This presentation provides a broad overview of metal hyperaccumulator plants and biological accumulation technology. Plants that have been identified as having the greatest potentials for development as phytoremediator crops for metal-contaminated soils are very briefly discussed. Phytoextraction, rhizofiltration, and phytostabilization are briefly defined. Issues pertinent to large scale phytoremediation of soils are discussed, including biological and technological constraints.

Baker, A.J.M. [Univ. of Sheffield (United Kingdom); Reeves, R.D. [Massey Univ., Palmerston North (New Zealand)

1996-12-31

229

Biological Soil Crusts and Water Relations in Australian Deserts  

Microsoft Academic Search

\\u000a In Australian rangelands, crusts comprise an assortment of lichens, bryophytes (mosses and liverworts), algae, cyanobacteria,\\u000a and assorted bacteria and fungi (see Chap. 10). Whilst biological crusts in Australia are rather thin and occur often in association\\u000a with physically or chemically crusted surfaces (Eldridge et al. 1995), they influence the flow of water through, and the movement of sediments over, the

D. J. Eldridge

230

The ice nucleation activity of biological aerosols  

NASA Astrophysics Data System (ADS)

Primary Biological Aerosol Particles (PBAPs), including bacteria, spores and pollen may be important for several atmospheric processes. Particularly, the ice nucleation caused by PBAPs is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate is not yet fully understood. In laboratory model studies we investigated the ice nucleation activity of selected PBAPs. We studied the immersion mode freezing using water-oil emulsion, which we observed by optical microscopy. We particularly focused on pollen. We show that pollen of different species strongly differ in their ice nucleation behavior. The average freezing temperatures in laboratory experiments range from 240 K to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen) have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. For comparison the ice nucleation activity of Snomax, fungal spores, and mushrooms will be discussed as well. In the past, pollen have been rejected as important atmospheric IN, as they are not as abundant in the atmosphere as bacteria or mineral dust and are too heavy to reach higher altitudes. However, in our experiments (Pummer et al. 2011) it turned out that water, which had been in contact with pollen and then been separated from the bodies, nucleates as good as the pollen grains themselves. So the ice nuclei have to be easily-suspendable macromolecules (100-300 kDa) located on the pollen. Once extracted, they can be distributed further through the atmosphere than the heavy pollen grains and so augment the impact of pollen on ice cloud formation even in the upper troposphere. It is widely known, that material from the pollen, like allergens and sugars, can indeed leave the pollen body and be distributed independently. The most probable mechanism is the pollen grain bursting by rain, which releases material, like allergens (Schäppi et al., 1999). As a consequence allergenic material was found in aerosol particles smaller than 5 µm, which contained no pollen or bigger fragments (Solomon et al., 1983). The release of material by bursting of wet pollen has been observed by electron microscopy (Swoboda et al., 2001). Not only allergens, but also sugars originating from pollen can be detected in the atmosphere (Yttri et al., 2007). These authors see pollen rupture and wood burning as their main sources in the atmosphere. The contrast between the hydrophilic properties of many of the surface components and the relative hydrophobia of the sporopollenin boosts the suspension of surface components in water droplets. According to that we conclude that the impact of pollen on the global atmosphere might have been underestimated. Additionally, our experiments lead to the conclusion that pollen ice nuclei, in contrast to bacterial and fungal ice nucleating proteins, are non-proteinaceous compounds.

Grothe, H.; Pummer, B.; Bauer, H.; Bernardi, J.

2012-04-01

231

HYDROGEN PEROXIDE DECAY IN WATERS WITH SUSPENDED SOILS: EVIDENCE FOR BIOLOGICALLY MEDIATED PROCESSES  

EPA Science Inventory

Hydrogen peroxide decay studies have been conducted in suspensions of several well-characterized soils and in natural water samples. inetic and product studies indicated that the decay was biologically mediated and could be described by psuedo first-order rate expressions. t an i...

232

METHODS FOR EVALUATING THE BIOLOGICAL IMPACT OF POTENTIALLY TOXIC WASTE APPLIED TO SOILS  

EPA Science Inventory

The study was designed to evaluate two methods that can be used to estimate the biological impact of organics and inorganics that may be in wastes applied to land for treatment and disposal. The two methods were the contact test and the artificial soil test. The contact test is a...

233

Methods for Evaluating the Biological Impact of Potentially Toxic Waste Applied to Soils.  

National Technical Information Service (NTIS)

The study was designed to evaluate two methods that can be used to estimate the biological impact of organics and inorganics that may be in wastes applied to land for treatment and disposal. The two methods were the contact test and the artificial soil te...

E. F. Neuhauser, R. C. Loehr, M. R. Malecki

1985-01-01

234

Soil Biology & Biochemistry 40 (2008) 978985 Belowground nematode herbivores are resistant to elevated atmospheric  

E-print Network

Soil Biology & Biochemistry 40 (2008) 978�985 Belowground nematode herbivores are resistant of herbivorous nematode populations to elevated CO2 concentrations from three distinct grassland experiments, elevated CO2 did not affect the abundance of nematode families; only two nematode families were

Wall, Diana

235

Effects of Altered Temperature and Precipitation on Desert Protozoa Associated with Biological Soil Crusts  

E-print Network

-third of the earth's land surface area. Global circulation models predict overall temperatures in the southwestEffects of Altered Temperature and Precipitation on Desert Protozoa Associated with Biological Soil and test the response of protozoa to increased temperature and precipitation as is predicted by some global

Neher, Deborah A.

236

Soil Biology & Biochemistry 39 (2007) 16551663 Relation between oak tree phenology and the secretion of organic  

E-print Network

Soil Biology & Biochemistry 39 (2007) 1655­1663 Relation between oak tree phenology as substrate. This is consistent with the hypothesis that it provides the oak trees with carbon when demand (Quercus petraea Matt. Liebl.) oaks are the most important deciduous forest tree species, ecologically

Bruns, Tom

237

Soil Biology & Biochemistry 40 (2008) 434442 Species-specific impacts of collembola grazing on  

E-print Network

Soil Biology & Biochemistry 40 (2008) 434­442 Species-specific impacts of collembola grazing are primary agents of organic matter decomposition in forests. Although invertebrate grazing affects fungal a multi-trophic approach to investigate the individual effects of invertebrate grazing on four species

Bruns, Tom

238

Influence of chemically and biologically stabilized sewage sludge on plant-available phosphorous in soil  

Microsoft Academic Search

The fertilizing effect of P in different sewage sludges was investigated in a pot experiment. Five different sludge types were applied to rye grass growing in either a moraine or a clay soil. The flocculating agents used to precipitate P in the sludges were aluminium chemicals, iron chloride or biological P-reduction without use of chemicals. The total P content in

Tore Krogstad; Trine A. Sogn; Ĺsmund Asdal; Arne Sćbř

2005-01-01

239

Selection of biological control agents for controlling soil and seed-borne diseases in the field  

Microsoft Academic Search

Different screening methods for selection of biological control agents (BCAs), for controlling soil and seed-borne diseases, are discussed. The shortcomings of laboratory methods focused on mechanism of action are discussed and we conclude that these methods should be used with caution if candidates with multifactorial or plant mediated mechanisms of control are to be obtained. In vitro screens may be

I. M. B. Knudsen; J. Hockenhull; D. Funck Jensen; B. Gerhardson; M. Hökeberg; R. Tahvonen; E. Teperi; L. Sundheim; B. Henriksen

1997-01-01

240

Cyclobutane-Containing Alkaloids: Origin, Synthesis, and Biological Activities  

PubMed Central

Present review describes research on novel natural cyclobutane-containing alkaloids isolated from terrestrial and marine species. More than 60 biological active compounds have been confirmed to have antimicrobial, antibacterial, antitumor, and other activities. The structures, synthesis, origins, and biological activities of a selection of cyclobutane-containing alkaloids are reviewed. With the computer program PASS some additional biological activities are also predicted, which point toward new possible applications of these compounds. This review emphasizes the role of cyclobutane-containing alkaloids as an important source of leads for drug discovery. PMID:19696873

Sergeiko, Anastasia; Poroikov, Vladimir V; Hanus, Lumir O; Dembitsky, Valery M

2008-01-01

241

Effects of Biological Soil Crusts on Seedling Growth and Mineral Content of Four Semiarid Herbaceous Plant Species  

Microsoft Academic Search

A growing body of evidence indicates that biological soil crusts of arid and semiarid lands contribute significantly to ecosys- tem stability by means of soil stabilization, nitrogen fixation, and improved growth and establishment of vascular plant species. In this study, we examined growth and mineral content of Bromus tectorum, Elymus elymoides, Gaillardia pulchella, and Sphaeralcea munroana grown in soil amended

R. L. Pendleton; B. K. Pendleton; G. L. Howard; S. D. Warren

242

Thermal and biological treatability studies on explosives-contaminated soil from a DOD site  

SciTech Connect

Laboratory- and bench-scale treatability studies were conducted on explosives-contaminated soil from the former Nebraska Ordnance Plant (NOP) Site by RUST Environment and Infrastructure (RUST) for the U.S. Army Corps of Engineers (USACE) in order to obtain site-specific information for technologies evaluated in the Feasibility Study for the site. Both thermal and biological treatment were identified in the Feasibility Study as technologies that could potentially be used to remediate the explosives-contaminated soil at the site. However, additional information specific to the chemical concentrations and soil properties of the site was required to fully evaluate these technologies. Therefore, these studies were initiated in order to gain more information. The studies summarized in this paper include a rotary kiln incineration and geotechnical study conducted by RUST, Cross/Tessitore and Associates (C/TA) under subcontract to RUST, and a biological treatment study conducted by Radian Corporation (Radian) under subcontract to RUST.

Shultz, S.R.; Taylor, C.; Shultz, D.W.R. [RUST Environment and Infrastructure, Inc., Sheboygan, WI (United States); Cichelli, J. [Army Corps of Engineers, Kansas City, MO (United States); Pinion, J. [Harding Lawson Associates/Cross/Tessitore and Associates, Orlando, FL (United States); Oolman, T. [Radian Corp., Austin, TX (United States)

1994-12-31

243

Soil surface disturbances in cold deserts: Effects on nitrogenase activity in cyanobacterial-lichen soil crusts  

USGS Publications Warehouse

CyanobacteriaMichen soil crusts can be a dominant source of nitrogen for cold-desert ecosystems. Effects of surface disturbance from footprints, bike and vehicle tracks on the nitrogenase activity in these crusts was investigated. Surface disturbances reduced nitrogenase activity by 30-100%. Crusts dominated by the cyanobacterium Microcoleus vaginatus on sandy soils were the most susceptible to disruption; crusts on gypsiferous soils were the least susceptible. Crusts where the soil lichen Collema tenax was present showed less immediate effects; however, nitrogenase activity still declined over time. Levels of nitrogenase activity reduction were affected by the degree of soil disruption and whether sites were dominated by cyanobacteria with or without heterocysts. Consequently, anthropogenic surface disturbances may have serious implications for nitrogen budgets in these ecosystems.

Belnap, Jayne

1996-01-01

244

The variation of morphological features and mineralogical components of biological soil crusts in the Gurbantunggut Desert of Northwestern China  

Microsoft Academic Search

Increasingly complex life forms were found in older biological soil crusts in the Gurbantaunggut Desert in Northwestern China.\\u000a These crusts may play a critical role in mineral erosion and desert soil formation by modifying the weathering environment\\u000a and ultimately affecting mineralogical variance. To test this hypothesis, variations in the morphological features and mineralogical\\u000a components of successional biological soil crusts at

Rongyi Chen; Yuanming Zhang; Yuan Li; Wenshou Wei; Jing Zhang; Nan Wu

2009-01-01

245

Seed water status and root tip characteristics of two annual grasses on lichen-dominated biological soil crusts  

Microsoft Academic Search

Biological soil crusts can affect seed germination and seedling establishment. We have investigated the effect of biological\\u000a soil crusts on seed water status as a potential mechanism affecting seed germination. The seed water potential of two annual\\u000a grasses, one exotic Bromus tectorum L. and another native Vulpia microstachys Nutt., were analyzed after placing the seeds on bare soil, on a

Marcelo D. Serpe; Shawna J. Zimmerman; Lynell Deines; Roger Rosentreter

2008-01-01

246

Tree Species Traits Influence Soil Physical, Chemical, and Biological Properties in High Elevation Forests  

PubMed Central

Background Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. Methodology/Principal Findings We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N) concentration and lowest lignin?N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin?N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid mites did not. Conclusions/Significance Although some soil characteristics were unaffected by tree species identity, our results clearly demonstrate that these dominant tree species are associated with soils that differ in several physical, chemical, and biotic properties. Ongoing environmental changes in this region, e.g. changes in fire regime, frequency of insect outbreaks, changes in precipitation patterns and snowpack, and land-use change, may alter the relative abundance of these tree species over coming decades, which in turn will likely alter the soils. PMID:19536334

Ayres, Edward; Steltzer, Heidi; Berg, Sarah; Wallenstein, Matthew D.; Simmons, Breana L.; Wall, Diana H.

2009-01-01

247

Role of Biological Soil Crusts on hydrological cycle drivers of semiarid ecosystems  

NASA Astrophysics Data System (ADS)

In arid and semiarid ecosystems, where plant cover is scarce, other surface components like soil crusts or stones acquire a very relevant role on local hydrologic regimes, controlling infiltration rates and they also affect erosion. The interplant spaces of these ecosystems are very often covered by biological soil crusts (BSCs), which are a community of microorganisms, including cyanobacteria, algae, fungi, lichens and mosses living in the soil surface. These BSCs regulate the horizontal and vertical fluxes of water, carbon, and nutrients into and from the soil and play crucial hydrological, geomorphological and ecological roles in these ecosystems. We analyse the role of BSCs on the different components of the water balance (infiltration-runoff, evaporation and soil moisture) in two representative semiarid ecosystems of SE Spain. The influence of BSCs on runoff-infiltration and erosion has been studied by rainfall simulations and with field plots under natural rainfall at different spatial scales, on BSCs in different stages of their development. Results show higher infiltration in BSCs than in physical crusts and different responses among BSCs depending on soil and rainfall properties and the considered spatial scale but, as a general trend, the greater the development of the BSCs, the greater the infiltration rate and the lower the sediment yield. In addition, given that BSCs modify many soil surface properties, such as surface stability, cohesiveness, cracking, porosity or micro-topography, which also affect runoff and erosion processes, we have examined the relative importance of BSCs features (cover, composition, roughness, water repellency, etc) on runoff and erosion and their direct and indirect relationships and how they interact with rainfall characteristics. By using microlysimeters, similar evaporative losses were measured among crust types in late spring when ambient conditions were quite warm and all crust types lost water very quickly. However, monitoring of soil moisture during a whole year shows differences in soil moisture content and soil water loss between the types of BSCs depending on the moment of the year. Thus, during wet periods higher soil moisture and slower soil water losses were recorded in lichen-covered than in cyanobacteria-covered soils. While during dry periods, faster soil water depletion and lower soil moisture occurred under lichen than in soils covered by cyanobacterial BSCs. In conclusion, our results show the important roles of BSCs modulating the water cycle in semiarid ecosystems.

Canton, Y.; Chamizo, S.; Rodriguez-Caballero, E.; Miralles, I.; Lazaro, R.; Sole-Benet, A.; Domingo, F.

2012-04-01

248

Relationships between soil biological and other soil properties in saline and alkaline arable soils from the Pakistani Punjab  

Microsoft Academic Search

In six regions of the Punjab forming a gradient in precipitation, soils differing in texture, salinity and sodicity were taken at 29 representative sites. The aim was to assess the effects of these interacting differences on microbial biomass C, biomass N, and biomass P in relation to their element-specific storage compartment, i.e. soil organic C, total N and total P.

S. Muhammad; T. Müller; R. G. Joergensen

2008-01-01

249

Biological soil crusts as key drivers for CO2 fluxes in semiarid ecosystems  

NASA Astrophysics Data System (ADS)

The quantification of carbon (C) fluxes for the different ecosystems and the knowledge of whether they act as sources or sinks of C has acquired especial importance during the last years. This is particularly demanding for arid and semiarid ecosystems, for which the available information is very scarce. In these ecosystems, the interplant spaces are commonly covered by a thin layer of organisms including cyanobacteria, green algae, lichens and mosses, which are known as biological soil crusts (BSCs) and, though practically negligible, play a fundamental role in regulating gas exchange into and from soil. BSCs represent the main organisms capable of respiration and photosynthesis in the interplant spaces and are considered the main source of organic carbon in many arid and semiarid areas. Although several studies have pointed to the predominant role of BSCs as sources of CO2, on the contrary, other studies have emphasized their important role as sinks of CO2, being required to establish their precise effect regulating CO2 fluxes. The main purpose of this study was to enlighten the role of BSCs on CO2 fluxes. With this aim, CO2 fluxes were measured on different BSC types (cyanobacteria-, lichen- and moss-dominated BSCs) after several rainfalls and periods of soil drying in two semiarid ecosystems of SE Spain. CO2 exchange was measured using infrared gas analyzers (IRGA): net flux was measured with a transparent custom chamber attached to a Licor Li-6400, and respiration with a respirometer EGM-4 (PPsystems). Photosynthesis was determined as the difference between both measurements. Our results showed that moisture was the major factor controlling CO2 fluxes in BSCs. During the summer season, when soil was dry, all BSCs showed CO2 fluxes close to 0. However, once it rains and BSCs become active, a significant increase in photosynthesis and respiration rates was found. Whereas respiration was the main CO2 flux in bare soils, in BSCs regardless respiration was higher, these CO2 emissions were compensated, during several days following the rain, by CO2 fixation through photosynthesis, thus resulting in a positive net flux or net uptake of CO2. However, differences were observed between BSC types. Moss-dominated BSCs, regardless being more developed than cyanobacteria and lichen BSCs, showed lower net photosynthesis rates because of their higher respiration rates. These findings support the idea that BSCs act as important C sinks during the periods when they are active, although the rate of CO2 assimilation may greatly depend on the type of BSC. The results of this study demonstrate the need to consider the effect of different types of BSC in C balance models on local to global scales to improve our knowledge on C quantification and to make more accurate predictions of the effects of climate change in arid and semiarid regions where this type of soil cover is a key ecosystem component.

Chamizo, Sonia; Miralles, Isabel; Rodríguez-Caballero, Emilio; Ortega, Raúl; Ladrón de Guevara, Mónica; Luna, Lourdes; Cantón, Yolanda

2014-05-01

250

Island biology and ecosystem functioning in epiphytic soil communities.  

PubMed

Although island attributes such as size and accessibility to colonizing organisms can influence community structure, the consequences of these for ecosystem functioning are little understood. A study of the suspended soils of spatially discrete epiphytes or treetop "islands" in the canopies of New Zealand rainforest trees revealed that different components of the decomposer community responded either positively or negatively to island size, as well as to the tree species that the islands occurred in. This in turn led to important differences between islands in the rates of ecosystem processes driven by the decomposer biota. This system serves as a model for better understanding how attributes of both real and habitat islands may affect key ecosystem functions through determining the community structure of organisms that drive these functions. PMID:14500981

Wardle, David A; Yeates, Gregor W; Barker, Gary M; Bellingham, Peter J; Bonner, Karen I; Williamson, Wendy M

2003-09-19

251

Biological and chemical interactions of pesticides with soil organic matter.  

PubMed

There is little doubt that organic matter plays a major role in the binding of pesticides in soil, and that this phenomenon is usually the most important cause for interaction of pesticides in the soil environment. Fulvic or humic acids are the chemicals most commonly involved in the binding interactions. Binding can occur with the original pesticide or a transformation product, the reaction being caused by abiotic agents or biotic agents (microbial or plant enzymes). The reactions or processes involved appear to be the same as those responsible for the formation of humic substances, i.e. for the humification process. Binding of pesticides to organic matter can occur by sorption (Van der Waal's forces, hydrogen bonding, hydrophobic bonding), electrostatic interactions (charge transfer, ion exchange or ligand exchange), covalent bonding or combinations of these reactions. Our investigation focused primarily on the binding of substituted phenols and aromatic amines to humus monomers and humic substances. In model reactions, we demonstrated the formation of covalent linkages between pesticides and humus constituents and fulvic or humic acids in the presence of phenol oxidases or clay minerals. With chlorinated phenols and carboxylic acids, it was possible to isolate and identify cross-coupling products and to elucidate the site and type of binding. The binding of chlorinated phenols to humic substances was determined by using 14C-labelled chemicals and by measuring the uptake of radioactivity by the humic material. These experiments provide a base for explaining the formation of bound residues in certain cases and for assuming the toxic potential of the immobilized pollutants. PMID:1439732

Bollag, J M; Myers, C J; Minard, R D

1992-08-12

252

Earthworm activities and the soil system  

Microsoft Academic Search

Earthworms find in soil the energy, nutrient resources, water and buffered climatic conditions that they need. According to the food resource they exploit and the general environmental conditions, earthworms can be grouped into different functional categories which differ essentially in morphology, size, pigmentation, distribution in the soil profile, ability to dig galleries and produce surface casts, demographic profiles and relationships

P. Lavelle

1988-01-01

253

Ficus carica L. (Moraceae): Phytochemistry, Traditional Uses and Biological Activities  

PubMed Central

This paper describes the botanical features of Ficus carica L. (Moraceae), its wide variety of chemical constituents, its use in traditional medicine as remedies for many health problems, and its biological activities. The plant has been used traditionally to treat various ailments such as gastric problems, inflammation, and cancer. Phytochemical studies on the leaves and fruits of the plant have shown that they are rich in phenolics, organic acids, and volatile compounds. However, there is little information on the phytochemicals present in the stem and root. Reports on the biological activities of the plant are mainly on its crude extracts which have been proven to possess many biological activities. Some of the most interesting therapeutic effects include anticancer, hepatoprotective, hypoglycemic, hypolipidemic, and antimicrobial activities. Thus, studies related to identification of the bioactive compounds and correlating them to their biological activities are very useful for further research to explore the potential of F. carica as a source of therapeutic agents. PMID:24159359

Mawa, Shukranul; Husain, Khairana; Jantan, Ibrahim

2013-01-01

254

Does soil biodiversity depend upon metabiotic activity and influences?  

Microsoft Academic Search

A central tenet of biological science is that living organisms modify their environments. Metabiosis is a form of ecological dependence in which one organism or a functional group of organisms must modify the environment before another organism or functional group of organisms can live or thrive in it. Soil ecosystems are modified by metabionts to create habitats or supply resources

John Saville Waid

1999-01-01

255

Soil Biology & Biochemistry 40: 1975-1979 (2008) http://dx.doi.org/10.1016/j.soilbio.2008.03.016 1 Variable selection in near infrared spectra for the biological  

E-print Network

Soil Biology & Biochemistry 40: 1975-1979 (2008) ­ http://dx.doi.org/10.1016/j.soilbio.2008.03.016 1 Variable selection in near infrared spectra for the biological characterization of soil reflectance spectroscopy (NIRS) was used to predict six biological properties of soil and earthworm casts

Boyer, Edmond

256

Do biotic interactions modulate ecosystem functioning along stress gradients? Insights from semi-arid plant and biological soil crust communities  

PubMed Central

Climate change will exacerbate the degree of abiotic stress experienced by semi-arid ecosystems. While abiotic stress profoundly affects biotic interactions, their potential role as modulators of ecosystem responses to climate change is largely unknown. Using plants and biological soil crusts, we tested the relative importance of facilitative–competitive interactions and other community attributes (cover, species richness and species evenness) as drivers of ecosystem functioning along stress gradients in semi-arid Mediterranean ecosystems. Biotic interactions shifted from facilitation to competition along stress gradients driven by water availability and temperature. These changes were, however, dependent on the spatial scale and the community considered. We found little evidence to suggest that biotic interactions are a major direct influence upon indicators of ecosystem functioning (soil respiration, organic carbon, water-holding capacity, compaction and the activity of enzymes related to the carbon, nitrogen and phosphorus cycles) along stress gradients. However, attributes such as cover and species richness showed a direct effect on ecosystem functioning. Our results do not agree with predictions emphasizing that the importance of plant–plant interactions will be increased under climate change in dry environments, and indicate that reductions in the cover of plant and biological soil crust communities will negatively impact ecosystems under future climatic conditions. PMID:20513714

Maestre, Fernando T.; Bowker, Matthew A.; Escolar, Cristina; Puche, María D.; Soliveres, Santiago; Maltez-Mouro, Sara; García-Palacios, Pablo; Castillo-Monroy, Andrea P.; Martínez, Isabel; Escudero, Adrián

2010-01-01

257

Proliferation of diversified clostridial species during biological soil disinfestation incorporated with plant biomass under various conditions.  

PubMed

Biological soil disinfestation (BSD) involves the anaerobic decomposition of plant biomass by microbial communities leading to control of plant pathogens. We analyzed bacterial communities in soil of a model experiment of BSD, as affected by biomass incorporation under various conditions, to find out the major anaerobic bacterial groups which emerged after BSD treatments. The soil was treated with Brassica juncea plants, wheat bran, or Avena strigosa plants, irrigated at 20 or 30 % moisture content and incubated at 25-30 °C for 17 days. The population of Fusarium oxysporum f. sp. spinaciae incorporated at the start of the experiment declined markedly for some BSD conditions and rather high concentrations of acetate and butyrate were detected from these BSD-treated soils. The polymerase chain reaction-denaturing gradient gel electrophoresis analysis based on the V3 region of 16S rRNA gene sequences from the soil DNA revealed that bacterial profiles greatly changed according to the treatment conditions. Based on the clone library analysis, phylogenetically diverse clostridial species appeared exceedingly dominant in the bacterial community of BSD soil incorporated with Brassica plants or wheat bran, in which the pathogen was suppressed completely. Species in the class Clostridia such as Clostridium saccharobutylicum, Clostridium acetobutylicum, Clostridium xylanovorans, Oxobacter pfennigii, Clostridium pasteurianum, Clostridium sufflavum, Clostridium cylindrosporum, etc. were commonly recognized as closely related species of the dominant clone groups from these soil samples. PMID:23132344

Mowlick, Subrata; Takehara, Toshiaki; Kaku, Nobuo; Ueki, Katsuji; Ueki, Atsuko

2013-09-01

258

Carbon exchange in biological soil crust communities under differential temperatures and soil water contents: implications for global change  

USGS Publications Warehouse

Biological soil crusts (biocrusts) are an integral part of the soil system in arid regions worldwide, stabilizing soil surfaces, aiding vascular plant establishment, and are significant sources of ecosystem nitrogen and carbon. Hydration and temperature primarily control ecosystem CO2 flux in these systems. Using constructed mesocosms for incubations under controlled laboratory conditions, we examined the effect of temperature (5-35 1C) and water content (WC, 20-100%) on CO2 exchange in light cyanobacterially dominated) and dark cyanobacteria/lichen and moss dominated) biocrusts of the cool Colorado Plateau Desert in Utah and the hot Chihuahuan Desert in New Mexico. In light crusts from both Utah and New Mexico, net photosynthesis was highest at temperatures 430 1C. Net photosynthesis in light crusts from Utah was relatively insensitive to changes in soil moisture. In contrast, light crusts from New Mexico tended to exhibit higher rates of net photosynthesis at higher soil moisture. Dark crusts originating from both sites exhibited the greatest net photosynthesis at intermediate soil water content (40-60%). Declines in net photosynthesis were observed in dark crusts with crusts from Utah showing declines at temperatures 425 1C and those originating from New Mexico showing declines at temperatures 435 1C. Maximum net photosynthesis in all crust types from all locations were strongly influenced by offsets in the optimal temperature and water content for gross photosynthesis compared with dark respiration. Gross photosynthesis tended to be maximized at some intermediate value of temperature and water content and dark respiration tended to increase linearly. The results of this study suggest biocrusts are capable of CO2 exchange under a wide range of conditions. However, significant changes in the magnitude of this exchange should be expected for the temperature and precipitation changes suggested by current climate models.

Grote, Edmund E.; Belnap, Jayne; Housman, David C.; Sparks, Jed P.

2010-01-01

259

Effects of CO[sub 2] and climate change on forest trees: Soil biology and enzymology  

SciTech Connect

Samples of Teracosm soils were analyzed shortly after initial setup to determine whether initial conditions were equivalent and matched expected values for local soils. Total and active fungal biomass, active bacterial biomass and protozoan numbers were reduced, with greatest decreases occurring in the A horizon. No effect was observed on total bacterial biomass, nematode or anthropod densities, but changes in nematode and arthropod species composition occurred. Significant differences in total density and species composition occurred between the enclosed Teracosms and the open controls. Arthropod and nematode community structure in the three altitudinal field sites had significantly diverged. No significant differences in activities of key soil enzymes in C- and N-cycling (acid phosphatase, protease, B-glucosidase, phenol oxidase and peroxidase) were found between initial samples relative to treatment, but all levels were significantly difference relative to depth in soil profile. Activities were within ranges previously observed in forests of the Pacific Northwest.

Moldenke, A.R.; Baumeister, N.; Caldwell, B.A.; Griffith, R.; Ingham, E.R.; Wernz, J. (Oregon State Univ., Corvallis, OR (United States)); Johnson, M.G.; Rygiewicz, P.T.; Tingey, D.T. (Environmental Protection Agency, Corvallis, OR (United States))

1994-06-01

260

Evaluation of the Soil Moisture Active Passive Mission (SMAP) merged radar-radiometer soil moisture algorithm  

Microsoft Academic Search

The Soil Moisture Active Passive (SMAP) mission is recommended by the U.S. National Research Council Committee on Earth Science and Applications from Space. The SMAP mission is under development with a target launch date in late 2014. The SMAP mission will provide high resolution (~9 km) soil moisture product at a global extent. The SMAP instrument architecture incorporates an L-band

N. Das; D. Entekhabi; E. G. Njoku

2010-01-01

261

Effects of Altered Temperature & Precipitation on Soil Bacterial & Microfaunal Communities as Mediated by Biological Soil Crusts  

SciTech Connect

With increased temperatures in our original pot study we observed a decline in lichen/moss crust cover and with that a decline in carbon and nitrogen fixation, and thus a probable decline of C and N input into crusts and soils. Soil bacteria and fauna were affected negatively by increased temperature in both light and dark crusts, and with movement from cool to hot and hot to hotter desert climates. Crust microbial biomass and relative abundance of diazotrophs was reduced greatly after one year, even in pots that were not moved from their original location, although no change in diazotroph community structure was observed. Populations of soil fauna moved from cool to hot deserts were affected more negatively than those moved from hot to hotter deserts.

Neher, Deborah A. [University of Vermont

2004-08-31

262

Studying the Activities of Microorganisms in Soil Using Slides.  

ERIC Educational Resources Information Center

Two implanted slide techniques are described by which activity of proteolylic bacteria and the growth of algae in the soil can be readily studied by school students using simple apparatus and methods. Variations are suggested for studying the effects of agricultural practices and environmental conditions on the soil bacteria and algae. (Author/DS)

Cullimore, D. Roy; Pipe, Annette E.

1980-01-01

263

ACID RAIN AND SOIL MICROBIAL ACTIVITY: EFFECTS AND THEIR MECHANISMS  

EPA Science Inventory

In the investigation, our aim was to determine if acid rain affects soil microbial activity and to identify possible mechanisms of observed effects. A Sierran forest soil (pH 6.4) planted with Ponderosa pine seedlings was exposed to simulated rain (pH 2.0, 3.0, 4.0 and 5.6) with ...

264

Biology Research Activities: Teacher's Edition (with Answers).  

ERIC Educational Resources Information Center

This book is part of the series "Explorations in Science" which contains enrichment activities for the general science curriculum. Each book in the series contains innovative and traditional projects for both the bright and average, the self-motivated, and those who find activity motivating. Each activity is self-contained and provides everything…

Newman, Barbara

265

Doan Thu et al. published in European Journal of Soil Biology The earthworm species Metaphire posthuma modulates the effect of organic  

E-print Network

Doan Thu et al. published in European Journal of Soil Biology 1 The earthworm species Metaphire earthworms. hal-00957550,version1-20Mar2014 #12;Doan Thu et al. published in European Journal of Soil Biology Jouquet) hal-00957550,version1-20Mar2014 Author manuscript, published in "European Journal of Soil Biology

Paris-Sud XI, Université de

266

Biologically active peptides and enzymatic approaches to their production  

Microsoft Academic Search

This review briefly surveys various classes of biologically active and flavor peptides that have been isolated and characterized in recent years, and analyzes emerging trends and advances in biotechnological methods for their production.

Iqbal Gill; Rosina López-Fandińo; Xavier Jorba; Evgeny N. Vulfson

1996-01-01

267

Multifunctional and biologically active matrices from multicomponent polymeric solutions  

NASA Technical Reports Server (NTRS)

The present invention relates to a biologically active functionalized electrospun matrix to permit immobilization and long-term delivery of biologically active agents. In particular the invention relates to a functionalized polymer matrix comprising a matrix polymer, a compatibilizing polymer and a biomolecule or other small functioning molecule. In certain aspects the electrospun polymer fibers comprise at least one biologically active molecule functionalized with low molecular weight heparin. Examples of active molecules that may be used with the multicomponent polymer of the invention include, for example, a drug, a biopolymer, for example a growth factor, a protein, a peptide, a nucleotide, a polysaccharide, a biological macromolecule or the like. The invention is further directed to the formation of functionalized crosslinked matrices, such as hydrogels, that include at least one functionalized compatibilizing polymer capable of assembly.

Kiick, Kristi L. (Inventor); Yamaguchi, Nori (Inventor)

2010-01-01

268

Methods of increasing secretion of polypeptides having biological activity  

DOEpatents

The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

Merino, Sandra

2013-10-01

269

Soil organic matter and biological soil quality indicators after 21 years of organic and conventional farming  

Microsoft Academic Search

Organic farming systems often comprise crops and livestock, recycle farmyard manure for fertilization, and preventive or biocontrol measures are used for plant protection. We determined indicators for soil quality changes in the DOK long-term comparison trial that was initiated in 1978. This replicated field trial comprises organic and integrated (conventional) farming systems that are typical for Swiss agriculture. Livestock based

Andreas Fließbach; Hans-Rudolf Oberholzer; Lucie Gunst; Paul Mäder

2007-01-01

270

The environmental biological signature: NGS profiling for forensic comparison of soils.  

PubMed

The identification of the source of a specific soil sample is a crucial step in forensic investigations. Rapid advances in next generation sequencing (NGS) technology and the strong reduction of the cost of sequencing have recently opened new perspectives. In the present work a metabarcoding approach has been successfully applied to forensic and environmental soil samples, allowing the accurate and sensitive analysis of microflora (mfDNA), plants, metazoa, and protozoa DNA. The identification of the biological component by DNA metabarcoding is a strong element for the discrimination of samples geologically very similar but coming for distinct environments. PMID:24807707

Giampaoli, S; Berti, A; Di Maggio, R M; Pilli, E; Valentini, A; Valeriani, F; Gianfranceschi, G; Barni, F; Ripani, L; Romano Spica, V

2014-07-01

271

Soil Properties, Nutrient Dynamics, and Soil Enzyme Activities Associated with Garlic Stalk Decomposition under Various Conditions  

PubMed Central

The garlic stalk is a byproduct of garlic production and normally abandoned or burned, both of which cause environmental pollution. It is therefore appropriate to determine the conditions of efficient decomposition, and equally appropriate to determine the impact of this decomposition on soil properties. In this study, the soil properties, enzyme activities and nutrient dynamics associated with the decomposition of garlic stalk at different temperatures, concentrations and durations were investigated. Stalk decomposition significantly increased the values of soil pH and electrical conductivity. In addition, total nitrogen and organic carbon concentration were significantly increased by decomposing stalks at 40°C, with a 5?100 ratio and for 10 or 60 days. The highest activities of sucrase, urease and alkaline phosphatase in soil were detected when stalk decomposition was performed at the lowest temperature (10°C), highest concentration (5?100), and shortest duration (10 or 20 days). The evidence presented here suggests that garlic stalk decomposition improves the quality of soil by altering the value of soil pH and electrical conductivity and by changing nutrient dynamics and soil enzyme activity, compared to the soil decomposition without garlic stalks. PMID:23226411

Han, Xu; Cheng, Zhihui; Meng, Huanwen

2012-01-01

272

Dynamic cyanobacterial response to hydration and dehydration in a desert biological soil crust.  

PubMed

Biological soil crusts (BSCs) cover extensive portions of the earth's deserts. In order to survive desiccation cycles and utilize short periods of activity during infrequent precipitation, crust microorganisms must rely on the unique capabilities of vegetative cells to enter a dormant state and be poised for rapid resuscitation upon wetting. To elucidate the key events involved in the exit from dormancy, we performed a wetting experiment of a BSC and followed the response of the dominant cyanobacterium, Microcoleus vaginatus, in situ using a whole-genome transcriptional time course that included two diel cycles. Immediate, but transient, induction of DNA repair and regulatory genes signaled the hydration event. Recovery of photosynthesis occurred within 1?h, accompanied by upregulation of anabolic pathways. Onset of desiccation was characterized by the induction of genes for oxidative and photo-oxidative stress responses, osmotic stress response and the synthesis of C and N storage polymers. Early expression of genes for the production of exopolysaccharides, additional storage molecules and genes for membrane unsaturation occurred before drying and hints at preparedness for desiccation. We also observed signatures of preparation for future precipitation, notably the expression of genes for anaplerotic reactions in drying crusts, and the stable maintenance of mRNA through dormancy. These data shed light on possible synchronization between this cyanobacterium and its environment, and provides key mechanistic insights into its metabolism in situ that may be used to predict its response to climate, and or, land-use driven perturbations. PMID:23739051

Rajeev, Lara; da Rocha, Ulisses Nunes; Klitgord, Niels; Luning, Eric G; Fortney, Julian; Axen, Seth D; Shih, Patrick M; Bouskill, Nicholas J; Bowen, Benjamin P; Kerfeld, Cheryl A; Garcia-Pichel, Ferran; Brodie, Eoin L; Northen, Trent R; Mukhopadhyay, Aindrila

2013-11-01

273

Dynamic cyanobacterial response to hydration and dehydration in a desert biological soil crust  

PubMed Central

Biological soil crusts (BSCs) cover extensive portions of the earth's deserts. In order to survive desiccation cycles and utilize short periods of activity during infrequent precipitation, crust microorganisms must rely on the unique capabilities of vegetative cells to enter a dormant state and be poised for rapid resuscitation upon wetting. To elucidate the key events involved in the exit from dormancy, we performed a wetting experiment of a BSC and followed the response of the dominant cyanobacterium, Microcoleus vaginatus, in situ using a whole-genome transcriptional time course that included two diel cycles. Immediate, but transient, induction of DNA repair and regulatory genes signaled the hydration event. Recovery of photosynthesis occurred within 1?h, accompanied by upregulation of anabolic pathways. Onset of desiccation was characterized by the induction of genes for oxidative and photo-oxidative stress responses, osmotic stress response and the synthesis of C and N storage polymers. Early expression of genes for the production of exopolysaccharides, additional storage molecules and genes for membrane unsaturation occurred before drying and hints at preparedness for desiccation. We also observed signatures of preparation for future precipitation, notably the expression of genes for anaplerotic reactions in drying crusts, and the stable maintenance of mRNA through dormancy. These data shed light on possible synchronization between this cyanobacterium and its environment, and provides key mechanistic insights into its metabolism in situ that may be used to predict its response to climate, and or, land-use driven perturbations. PMID:23739051

Rajeev, Lara; da Rocha, Ulisses Nunes; Klitgord, Niels; Luning, Eric G; Fortney, Julian; Axen, Seth D; Shih, Patrick M; Bouskill, Nicholas J; Bowen, Benjamin P; Kerfeld, Cheryl A; Garcia-Pichel, Ferran; Brodie, Eoin L; Northen, Trent R; Mukhopadhyay, Aindrila

2013-01-01

274

SMOS Soil moisture Cal val activities  

NASA Astrophysics Data System (ADS)

SMOS, successfully launched on November 2, 2009, uses an L Band radiometer with aperture synthesis to achieve a good spatial resolution.. It was developed and made under the leadership of the European Space Agency (ESA) as an Earth Explorer Opportunity mission. It is a joint program with the Centre National d'Etudes Spatiales (CNES) in France and the Centro para el Desarrollo Tecnologico Industrial (CDTI) in Spain. SMOS carries a single payload, an L band 2D interferometric,radiometer in the 1400-1427 MHz protected band. This wavelength penetrates well through the vegetation and with the atmosphere being almost transparent, it enables us to infer both soil moisture and vegetation water content. SMOS achieves an unprecedented spatial resolution of 50 km at L-band maximum (43 km on average) with multi angular-dual polarized (or fully polarized) brightness temperatures over the globe and with a revisit time smaller than 3 days. SMOS is now acquiring data and has undergone the commissioning phase. The data quality exceeds what was expected, showing very good sensitivity and stability. The data is however very much impaired by man made emission in the protected band, leading to degraded measurements in several areas including parts of Europe and China. Many different international teams are now performing cal val activities in various parts of the world, with notably large field campaigns either on the long time scale or over specific targets to address the specific issues. These campaigns take place in various parts of the world and in different environments, from the Antarctic plateau to the deserts, from rain forests to deep oceans. SMOS is a new sensor, making new measurements and paving the way for new applications. It requires a detailed analysis of the data so as to validate both the approach and the quality of the retrievals, and allow for monitoring and the evolution of the sensor. To achieve such goals it is very important to link efficiently ground measurement to satellite measurements through field campaigns and related airborne acquisitions. Comparison with models and other satellite products are necessary. It is in this framework that CESBIO has been involved with many groups to assess the data over many areas in close collaboration. This paper aims at summarising briefly the results (presented in detail in other presentations) to give a general overview and a general first taste of SMOS' performance, together with the identified gaps and next steps to be taken. This presentation could be the general introduction to Cal Val activities.

Kerr, Y.; Mialon, A.; Bitar, A. Al; Leroux, D.; Richaume, P.; Gruhier, C.; Berthon, L.; Novello, N.; Rudiger, C.; Bircher, S.; Wigneron, J. P.; Ferrazzoli, P.; Rahmoune, R.

2012-04-01

275

Soil Moisture Profile Estimation From Active Microwave Earth Observations  

NASA Astrophysics Data System (ADS)

This paper discusses the potential of retrieving information about the soil moisture profile from measurements of the surface soil moisture content through active mi- crowave observations of the Earth. In a series of laboratory experiments using multi- frequency radar observations of bare surfaces, Mancini et al. (1999) have shown that accurate surface soil moisture retrieval by means of C and L band active microwave observations is feasible. Hoeben and Troch (2000) combined active microwave obser- vations of the surface soil moisture content and 1D dynamic modeling of the unsat- urated zone in a data assimilation framework to show that this allows the retrieval of the root zone soil moiture profile. They showed that even in the presence of model and observation noise and infrequent observations, accurate retrieval of the entire soil moisture profile is possible for bare soil. Van Loon and Troch (2002) developed a ro- bust 4D data assimilation procedure applicable at the catchment scale. Their 4DDA is based on Tikhonov regularization or generalized cross-validation. Recently, this pro- cedure has been extended to operate in recursive mode, making the algorithm more general applicable for soil moisture data assimilation at the catchment scale. Possible applications of this algorithm in the context of ENVISAT ASAR instrument will be discussed.

Troch, P. A.; van Loon, E. E.

276

Measurement of dinitrogen fixation by Biological soil crust (BSC) from the Sahelian zone: an isotopic method.  

NASA Astrophysics Data System (ADS)

Amongst the described ecological roles of Biological Soil Crust, N fixation is of importance for soil fertility, especially in arid and semi-arid ecosystems with low inputs. In BSC, the quantification of N fixation fluxes using an indirect method is widespread, usually with the Acetylene Reduction Assay (ARA) which consists in measuring the nitrogenase activity through the process of acetylene reduction into ethylene. A converting factor, still discussed in the literature and greatly depending of the constitutive organisms of the BSC, is the tool used to convert the amount of reduced ethylene into quantitative fixed Nitrogen. The aim of this poster is to describe an isotopic direct method to quantify the atmospheric dinitrogen fixation fluxes in BSC, while minimizing the variability due to manipulations. Nine different BSC from the Sahelian zone were selected and placed in an incubation room at 28° C in dark and light conditions during three days, while moisture equivalent to pF=2 was regularly adjusted using the gravimetric method with needles and deionized water, in order to activate and reach a dynamic stability of their metabolisms. Subsequently, each crust was placed into a gas-tight glass vial for incubation with a reconstituted 15N2 enriched atmosphere (31.61 % atom 15N, while the proportion of each main gas present in the air was conserved, i.e. 78% N2, 21% O2 and 0.04% CO2). Principal difficulties are to guarantee the airtighness of the system, to avoid crust desiccation and to keep the crust metabolically active under stable conditions for six hours. Several tests were performed to determine the optimum time for 15N2 incubation. Three replicated control samples per crust were also stabilized for three days and then dried at 105° C, without any incubation with 15N2 enriched atmosphere. Total N and 15N were then measured in the grounded (80?m) and dried (105° C) crust, using a Flash EA elemental analyzer (Eurovector, Milan, Italy) coupled to a DeltaPlus Advantage mass spectrometer (Finnigan Thermo Fisher Scientific, Bremen, Germany). N2fixation fluxes were calculated from the difference between the amount of 15N in incubated and in control samples. Mean values ranged from 1.32.10-3 ± 1.02.10-4 to 8.47.10-2 ± 2.63.10-3 mgN.m-2.h-1. Concerning the variability, differences observed between crusts and between replicates are probably related to the characteristic of each crust as well as to field sampling which integrates the important heterogeneity and sensitivity of the material.

Ehrhardt, F.; Alavoine, G.; Bertrand, I.

2012-04-01

277

The NASA Soil Moisture Active Passive (SMAP) mission: Overview  

E-print Network

The Soil Moisture Active Passive (SMAP) mission is one of the first Earth observation satellites being developed by NASA in response to the National Research Council's Decadal Survey. Its mission design consists of L-band ...

O'Neill, Peggy

278

Evidence for micronutrient limitation of biological soil crusts: potential to impact aridlands restoration  

E-print Network

Abstract. Desertification is a global problem, costly to national economies and human societies. Restoration of biological soil crusts (BSCs) may have an important role to play in the reversal of desertification due to their ability to decrease erosion and enhance soil fertility. To determine if there is evidence that lower fertility may hinder BSC recolonization, we investigated the hypothesis that BSC abundance is driven by soil nutrient concentrations. At a regional scale (north and central Colorado Plateau, USA), moss and lichen cover and richness are correlated with a complex water–nutrient availability gradient and have approximately six-fold higher cover and approximately two-fold higher species richness on sandy soils than on shale-derived soils. At a microscale, mosses and lichens are overrepresented in microhabitats under the north sides of shrub canopies, where water and nutrients are more available. At two spatial scales, and at the individual species and community levels, our data are consistent with the hypothesis that distributions of BSC organisms are determined largely by soil fertility. The micronutrients Mn and Zn figured prominently and consistently in the various analyses, strongly suggesting that these elements are previously unstudied limiting factors in BSC development. Structural-equation modeling of our data

unknown authors

2005-01-01

279

Influence of acetamiprid on soil enzymatic activities and respiration  

Microsoft Academic Search

The effect of a new pesticide, acetamiprid, applied at normal field concentration (0.5 mg kg?1 dried soil) and at high concentration (5 and 50 mg kg?1 dried soil), on soil enzyme activities and soil respiration in upland soil was studied. The results showed that acetamiprid had a strong negative influence on soil respiration and phosphatase activity, and the enzyme activities in soil treated with

Xiao-hua Yao; Hang Min; Zhen-hua Lü; Hai-ping Yuan

2006-01-01

280

Soil microbial activities beneath Stipa tenacissima L. and in surrounding bare soil  

NASA Astrophysics Data System (ADS)

Open steppes dominated by Stipa tenacissima L. constitute one of the most representative ecosystems of the semi-arid zones of Eastern Mediterranean Basin (Iberian Peninsula, North of Africa). These steppes show a higher degree of variability in composition and structure. Ecosystem functioning is strongly related to the spatial pattern of grass tussocks. Soils beneath S. tenacissima grass show higher fertility and improved microclimatic conditions, favouring the formation of "resource islands" (Maestre et al., 2007). On the other hand in "resource islands" and in surrounding bare soil exists the belowground zone of influence. The competition for water and resources between plants and microorganisms is strong and mediated trough an enormous variety of exudates and resource depletion intended to regulate soil microbial communities in the rhizosphere, control herbivory, encourage beneficial symbioses, and change chemical and physical properties in soil (Pugnaire et Armas, 2008). Secondary compounds and allelopathy restrict other species growth and contribute to patchy plant distribution. Active root segregation affects not only neighbour? growth but also soil microbial activities. The objective of this study was to assess the effect of Stipa tenacissima on the key soil microbial activities under controlled incubation conditions (basal and potential respiration; net nitrogen mineralization). The experimental plots were located in the province Almería in Sierra de los Filabres Mountains near the village Gérgal (southeast Spain) in the small catchment which is situated between 1090 - 1165 m a.s.l. The area with extent of 82 000 m2 is affected by soil degradation. The climate is semiarid Mediterranean. The mean annual rainfall is of about 240 mm mostly concentrated in autumn and spring. The mean annual temperature is 13.9° C. The studied soil has a loam to sandy clay texture and is classified as Lithosol (FAO-ISRIC and ISSS, 1998). The vegetation of these areas is an open steppe dominated by Stipa tenacissima. In February 2009 representative soil samples from the top 10 cm were taken beneath grass tussock and from bare soil. Soil samples in three replicates were incubated after rewetting with distilled water (basal microbial activities) and after rewetting with the glucose solution and with the mixture of glucose and peptone solution (potential microbial activities). The CO2, C2H4 evolved under controlled conditions (60% WHC, 24°C) during a 37-day aerobic incubation were determined. Ammonia and nitrate nitrogen were estimated in percolates after simulated rainfall (on the 16th day of incubation) and in the incubated soil samples at the end of incubation. Net ammonification and net nitrification rates were determined by subtracting initial soil mineral N from both mineral N in percolates plus final mineral N contents at 37th day. Basal, potential microbial respiration and net nitrification in the soils beneath S. tenacissima were, in general, not significantly different from the bare soils. The differences between plant-covered soil and bare soil in cumulative values of CO2 production and in amounts of accumulated NO3--N (net nitrification) were less than ± 10%. Greater differences were found in the net ammonification, which were higher beneath S. tenacissima, mainly in the control (basal activities) variant (about 38 %). Significantly less ethylene produced by microbial activity in soils beneath S. tenacissima after the addition of glucose indicates the dependence of rhizospheric microbial communities on available carbon compounds mainly from root exudates. It can be concluded, similarly as published Goberna et al., (2007), that the distribution of soil microbial properties in semi-arid Mediterranean ecosystems is not necessarily associated with the patchy plant distribution and that some microbial activities characteristics can be unexpectedly homogenous.

Novosadová, I.; Ruiz Sinoga, J. D.; Záhora, J.; Fišerová, H.

2010-05-01

281

Significance of earthworms in stimulating soil microbial activity  

Microsoft Academic Search

The stimulatory effect of earthworms (Lumbricus terrestris L.) on soil microbial activity was studied under microcosm-controlled conditions. The hypothesis was tested that microbial\\u000a stimulation observed in the presence of a soil invertebrate would be due to the utilization of additional nutritive substances\\u000a (secretion and excretion products) that it provides. Changes in microbial activity were monitored by measuring simultaneously\\u000a CO2 release

F. Binet; L. Fayolle; M. Pussard; J. J. Crawford; S. J. Traina; O. H. Tuovinen

1998-01-01

282

Accommodating Students with Disabilities in Soil Science Activities  

NSDL National Science Digital Library

Soil science education is lacking in terms of accommodations for persons with disabilities to the extent that these individuals are often excluded from soil science activities in school, and from careers in the discipline. This article describes a study whose goal was to develop accommodations to the soils protocols currently being used in the GLOBE (Global Learning Observations to Benefit the Environment) program. These new materials are based on the principles of universal design in education (UDE), so that GLOBE activities and materials can be accessible to a broad range of students, including students with disabilities.

Langley-Turnbaugh, S.

283

Fate and activity of microorganisms introduced into soil.  

PubMed Central

Introduced microorganisms are potentially powerful agents for manipulation of processes and/or components in soil. Fields of application include enhancement of crop growth, protection of crops against plant-pathogenic organisms, stimulation of biodegradation of xenobiotic compounds (bioaugmentation), and improvement of soil structure. Inoculation of soils has already been applied for decades, but it has often yielded inconsistent or disappointing results. This is caused mainly by a commonly observed rapid decline in inoculant population activity following introduction into soil, i.e., a decline of the numbers of inoculant cells and/or a decline of the (average) activity per cell. In this review, we discuss the available information on the effects of key factors that determine the fate and activity of microorganisms introduced into soil, with emphasis on bacteria. The factors addressed include the physiological status of the inoculant cells, the biotic and abiotic interactions in soil, soil properties, and substrate availability. Finally, we address the possibilities available to effectively manipulate the fate and activity of introduced microorganisms in relation to the main areas of their application. PMID:9184007

van Veen, J A; van Overbeek, L S; van Elsas, J D

1997-01-01

284

Active and total prokaryotic communities in dryland soils.  

PubMed

The relationship between total and metabolically active soil microbial communities can change drastically with environment. In dry lands, water availability is a key factor limiting cells' activity. We surveyed the diversity of total and active Archaea and Bacteria in soils ranging from arid desert to Mediterranean forests. Thirty composited soil samples were retrieved from five sites along a precipitation gradient, collected from patches located between and under the dominant perennial plant at each site. Molecular fingerprinting was used to site-sort the communities according of their 16S rRNA genes (total community) and their rRNA (active community) amplified by PCR or RT-PCR from directly extracted soil nucleic acids. The differences between soil samples were much higher in total rather than active microbial communities: differences in DNA fingerprints between sites were 1.2 and 2.5 times higher than RNA differences (for Archaea and Bacteria, respectively). Patch-type discrepancies between DNA fingerprints were on average 2.7-19.7 times greater than RNA differences. Moreover, RNA-based community patterns were highly correlated with soil moisture but did not necessarily follow spatial distribution pattern. Our results suggest that in water-limited environments, the spatial patterns obtained by the analysis of active communities are not as robust as those drawn from total communities. PMID:23730745

Angel, Roey; Pasternak, Zohar; Soares, M Ines M; Conrad, Ralf; Gillor, Osnat

2013-10-01

285

Effects of inoculated Microcoleus vaginatus on the structure and function of biological soil crusts of desert  

Microsoft Academic Search

Microcoleus vaginatus Gom., the dominant species in biological soil crusts (BSCs) in desert regions, plays a significant role in maintaining the\\u000a BSC structure and function. The BSC quality is commonly assessed by the chlorophyll a content, thickness, and compressive\\u000a strength. Here, we have studied the effect of different proportions of M. vaginatus, collected from the Gurbantunggut Desert in northwestern China,

Yunpu Zheng; Ming Xu; Jiancheng Zhao; Shuqing Bei; Lihua Hao

2011-01-01

286

Impacts of Biological Soil Crust Disturbance and Composition on C and N Loss from Water Erosion  

Microsoft Academic Search

In this study, we conducted rainfall simulation experiments in a cool desert ecosystem to examine the role of biological soil\\u000a crust disturbance and composition on dissolved and sediment C and N losses. We compared runoff and sediment C and N losses\\u000a from intact late-successional dark cyanolichen crusts (intact) to both trampled dark crusts (trampled) and dark crusts where\\u000a the top

Nichole N. Barger; Jeffrey E. Herrick; Justin Van Zee; Jayne Belnap

2006-01-01

287

A predictive model of spatial distribution of Biological Soil Crust in the Sahel from local to regional scale  

NASA Astrophysics Data System (ADS)

The Sahel region in West Africa is highly vulnerable facing soil degradation due to the harsh climatic conditions, with variable rainfall, and high anthropic pressure on land use. In Sahel, as in other arid environments, biological soil crusts are present over a large area. The BIOCRUST project focuses on the use of BSC as an indicator of environmental quality in the context of climate change and human activities pressures and on providing useful informations for best management practices for the Sahelian environment. To this end, a characterisation of BSC is required first at a local level based on the use of Very High Resolution satellite imagery. Two detailed field campaigns were undertaken to identify key variables indicative of the presence of biological soil crusts. A Statistic analysis ascertained that vegetation cover, land use, soil types and rainfall were the most significant variables to consider. From these, a predictive model of the spatial distribution of BSC was developed, based on a logistic regression. The extraction of the variables from the satellite imagery makes it possible to run the prediction model for 2 catchment areas of about 50km2 each situated in Niger on a North South transect. With a view to apply the prediction model to the central part of the Sahel scale, the same methodology was used with Medium Resolution satellite imagery and field data collected on a North South transect in Niger and Burkina Faso. Preliminary results indicate that the model is applicable at regional scale and show the potential spatial distribution of BSCs over a large portion of the Central part of the Sahel region.

Beaugendre, N.; Choné, A.; Sannier, C.; Desprats, J. F.; Cerdan, O.; Valentin, C.; Malam Issa, O.; Rajot, J. L.

2012-04-01

288

Biotoxicity assessment of pyrene in soil using a battery of biological assays.  

PubMed

A test battery, composed of a range of biological assays, was applied to evaluate the ecological health of soil aged for 69 days and spiked with a range of pyrene levels (1.04, 8.99, 41.5, 72.6, 136, and 399 ?g g(-1) dry soil; Soxhlet-extracted concentrations after 69 days of aging). Chinese cabbage (Brassica rapa), earthworm (Eisenia fetida), and bacteria (Vibrio fischeri) were used as test organisms to represent different trophic levels. Among the acute ecotoxicity bioassays used, the V. fischeri luminescence inhibition assay was the most sensitive indicator of pyrene toxicity. We observed >8 % light inhibition at the lowest concentration (1.04 ?g g(-1)) pyrene, and this inhibition increased to 60 % at 72.6 ?g g(-1). The sensitivity ranking for toxicity of the pyrene-contaminated soil in the present study was in the following decreasing order: root elongation of Chinese cabbage < earthworm mortality (14 days) < earthworm mortality (28 days) < luminescence inhibition (15 min) < luminescence inhibition (5 min). In addition, genotoxic effects of pyrene were also evaluated by using comet assay in E. fetida. The strong relationship between DNA damage and soil pyrene levels showed that comet assay is suitable for testing the genotoxicity of pyrene-polluted soil. In addition, tail moment was well correlated with soil pyrene levels (r (2) = 0.99). Thus, tail moment may be the most informative DNA-damage parameter representing the results of comet assay. Based on these results, the earthworm DNA damage assay and Microtox test are rapid and sensitive bioassays and can be used to assess the risk of soil with low to high levels of hydrocarbon pollution. Furthermore, an analysis of the toxic effects at several trophic levels is essential for a more comprehensive understanding of the damage caused by highly contaminated soil. PMID:22941450

Khan, Muhammad Imran; Cheema, Sardar Alam; Tang, Xianjin; Shen, Chaofeng; Sahi, Shahbaz Talib; Jabbar, Abdul; Park, Joonhong; Chen, Yingxu

2012-11-01

289

Assessing the chemical and biological accessibility of the herbicide isoproturon in soil amended with biochar.  

PubMed

There is considerable current interest in using biochar (BC) as a soil amendment to sequester carbon to mitigate climate change. However, the implications of adding BC to agricultural soil for the environmental fate of pesticides remain unclear. In particular, the effect of biochars on desorption behavior of compounds is poorly understood. This study examined the influence of BC on pesticide chemical and biological accessibility using the herbicide isoproturon (IPU). Soils amended with 1% and 2% BC showed enhanced sorption, slower desorption, and reduced biodegradation of IPU. Addition of 0.1% BC had no effect on sorption, desorption or biodegradation of IPU. However, the mineralization of (14)C-IPU was reduced by all BC concentrations, reducing by 13.6%, 40.1% and 49.8% at BC concentrations of 0.1%, 1% and 2% respectively. Further, the ratio of the toxic metabolite 4-isopropyl-aniline to intact IPU was substantially reduced by higher BC concentrations. Hydroxypropyl-?-cyclodextrin (HPCD) extractions were used to estimate the IPU bioaccessibility in the BC-amended soil. Significant correlations were found between HPCD-extracted (14)C-IPU and the IPU desorbed (%) (r(2)=0.8518, p<0.01), and also the (14)C-IPU mineralized (%) (r(2)=0.733; p<0.01) for all BC-amended soils. This study clearly demonstrates how desorption in the presence of BC is intimately related to pesticide biodegradation by the indigenous soil microbiota. BC application to agricultural soils can affect the persistence of pesticides as well as the fate of their degradation products. This has important implications for the effectiveness of pesticides as well as the sequestration of contaminants in soils. PMID:22464863

Sopeńa, Fatima; Semple, Kirk; Sohi, Saran; Bending, Gary

2012-06-01

290

ASSESSMENT OF GENOTOXIC ACTIVITY OF PETROLEUM HYDROCARBON-BIOREMEDIATED SOIL  

SciTech Connect

The relationship between toxicity and soil contamination must be understood to develop reliable indicators of environmental restoration for bioremediation. Two bacterial rapid bioassays: SOS chromotest and umu-test with and without metabolic activation (S-9 mixture) were used to evaluate genotoxicity of petroleum hydrocarbon-contaminated soil following bioremediation treatment. The soil was taken from an engineered biopile at the Czor Polish oil refinery. The bioremediation process in the biopile lasted 4 years, and the toxicity measurements were done after this treatment. Carcinogens detected in the soil, polyaromatic hydrocarbons (PAHs), were reduced to low concentrations (2 mg/kg dry wt) by the bioremediation process. Genotoxicity was not observed for soils tested with and without metabolic activation by a liver homogenate (S-9 mixture). However, umu-test was more sensitive than SOS-chromotest in the analysis of petroleum hydrocarbon-bioremediated soil. Analytical results of soil used in the bioassays confirmed that the bioremediation process reduced 81 percent of the petroleum hydrocarbons including PAHs. We conclude that the combined test systems employed in this study are useful tools for the genotoxic examination of remediated petroleum hydrocarbon-contaminated soil.

BRIGMON, ROBIN

2004-10-20

291

Controls of biological soil crust cover and composition shift with succession in sagebrush shrub-steppe  

USGS Publications Warehouse

Successional stage may determine strength and causal direction of interactions among abiotic and biotic factors; e.g., species that facilitate the establishment of other species may later compete with them. We evaluated multivariate hypotheses about abiotic and biotic factors shaping biological soil crusts (BSCs) in early and late successional stages. We surveyed vegetation and BSC in the shrub-steppe ecosystem of the Columbia Basin. We analyzed the relationships with bryophyte and lichen covers using structural equation models, and analyzed the relationships with BSC composition using Indicator Species Analysis and distance-based linear models. Cover, indicator species, and composition varied with successional stage. Increasing elevation and bryophyte cover had higher lichen cover early in succession; these relationships were negative in the later successional stage. Lichen cover did not appear to impede B. tectorum cover, but B. tectorum appeared to strongly negatively affect lichen cover in both stages. Biological soil crust composition varied with bunchgrass cover in the early successional stage, but with elevation and B. tectorum cover later in succession. Our findings support the hypotheses that as succession progresses, the strength and direction of certain community interactions shift, and B. tectorum leads to reductions in biological soil crust cover regardless of successional stage.

Dettweiler-Robinson, E.; Bakker, J.D.; Grace, J.B.

2013-01-01

292

Phosphatase activity in Antarctica soil samples as a biosignature of extant life  

NASA Astrophysics Data System (ADS)

Microbial activities have been detected in such extreme terrestrial environments as deep lithosphere, a submarine hydrothermal systems, stratosphere, and Antarctica. Microorganisms have adapted to such harsh environments by evolving their biomolecules. Some of these biomolecules such as enzymes might have different characteristics from those of organisms in ordinary environments. Many biosignatures (or biomarkers) have been proposed to detect microbial activities in such extreme environments. A number of techniques are proposed to evaluate biological activities in extreme environments including cultivation methods, assay of metabolism, and analysis of bioorganic compounds like amino acids and DNA. Enzyme activities are useful signature of extant life in extreme environments. Among many enzymes, phosphatase could be a good indicator of biological activities, since phosphate esters are essential for all the living terrestrial organisms. In addition, alkaline phosphatase is known as a typical zinc-containing metalloenzyme and quite stable in environments. We analyzed phosphatase activities in Antarctica soil samples to see whether they can be used as biosignatures for extant life. In addition, we characterized phosphatases extracted from the Antarctica soil samples, and compared with those obtained from other types of environments. Antarctica surface environments are quite severe environments for life since it is extremely cold and dry and exposed to strong UV and cosmic rays. We tried to evaluate biological activities in Antarctica by measuring phosphatase activities. Surface soil samples are obtained at the Sites 1-8 near Showa Base in Antarctica during the 47th Japan Antarctic exploration mission in 2005-6. Activities of acid phosphatase (ACP) and alkaline phosphatase (ALP) are measured spectrophotometrically after mixing the powdered sample and p-nitrophenyl phosphate solution (pH 6.5 for ACP, pH 8.0 for ALP). ALP was characterized after extraction from soils with Tris-HCl buffer (pH 9.0), where the activity was measured fluorometrically with 4-methylumbelliferyl phosphate (pH 8.0) as a substance. The soil of Site 8 (near a penguin rookery) showed almost the same level of ACP and ALP activities as usual surface soil sampled in YNU campus, while the soil of Sites 1-7 showed much less activities. ALP in the extract from the soil of Site 8 was characterized. It showed the maximal at 338 K, while ALP from the campus soil showed the maximal at 358 K. Gel filtration chromatography showed that the ALP activity was found only in the fraction whose molecular weights were over 60000. The ALP activity was diminished with EDTA and was recovered with addition of zinc ion. The present results showed that zinc-containing metalloenzymes, which had lower optimum temperature than those in usual environments, are present in Antarctica soil. It was suggested that phosphatases are good bio-signatures for extant life in extreme environments.

Sato, Shuji; Itoh, Yuki; Takano, Yoshinori; Fukui, Manabu; Kaneko, Takeo; Kobayashi, Kensei

293

Global High Resolution Soil Moisture Product from the Soil Moisture Active Passive (SMAP) Mission  

NASA Astrophysics Data System (ADS)

The SMAP mission is under development with a target launch date in late 2014. The SMAP mission will provide high resolution (~9 km) and frequent revisit (2-3 days) soil moisture product at a global extent. The SMAP instrument architecture incorporates an L-band (1.26 GHz) radar and an L-band (1.41 GHz) radiometer that share a single feedhorn and parabolic mesh reflector. The SMAP radiometer and radar instruments are capable of measuring surface soil moisture under moderate vegetation cover individually, however, the instruments suffer from limitations on spatial resolution (radiometer) and sensitivity (radar), respectively. To overcome the limitations of the individual passive and active approaches, the SMAP mission will combine the two data streams to generate an active-passive intermediate resolution and accuracy soil moisture product. The baseline active-passive algorithm disaggregates the coarse resolution (~36 km) radiometer brightness temperature (Tb) measurements using the spatial pattern within the radiometer footprint as inferred from the high resolution coincident radar co-pol and cross-pol backscatter measurements, and then inverts the disaggregated Tb to retrieve soil moisture.Studies are conducted to evaluate the baseline and optional active-passive algorithms at a global extent using a SMAP orbit simulator that provides capability for end-to-end simulation environment. Various aspects of the baseline active/passive algorithm are evaluated that are to be included in the 9 km global soil moisture product. Soil moisture retrieval results from global-extent study area demonstrate that the mission will meet its requirements of global coverage with an accuracy of <0.04 cm3/cm3 in soil moisture for region below 5 kg/m2 vegetation water content having ~9 km spatial and 3 days temporal resolution.The presentation will introduce the scientific community on the SMAP combined active-passive soil moisture product by especially focusing on product accuracy, retrieval characteristics, flags, retrieval thresholds and masks. SMAP

Das, N. N.; Entekhabi, D.; Njoku, E. G.

2013-12-01

294

Biologically active compounds of semi-metals.  

PubMed

Semi-metals (boron, silicon, arsenic and selenium) form organo-metal compounds, some of which are found in nature and affect the physiology of living organisms. They include, e.g., the boron-containing antibiotics aplasmomycin, borophycin, boromycin, and tartrolon or the silicon compounds present in "silicate" bacteria, relatives of the genus Bacillus, which release silicon from aluminosilicates through the secretion of organic acids. Arsenic is incorporated into arsenosugars and arsenobetaines by marine algae and invertebrates, and fungi and bacteria can produce volatile methylated arsenic compounds. Some prokaryotes can use arsenate as a terminal electron acceptor while others can utilize arsenite as an electron donor to generate energy. Selenium is incorporated into selenocysteine that is found in some proteins. Biomethylation of selenide produces methylselenide and dimethylselenide. Selenium analogues of amino acids, antitumor, antibacterial, antifungal, antiviral, anti-infective drugs are often used as analogues of important pharmacological sulfur compounds. Other metalloids, i.e. the rare and toxic tellurium and the radioactive short-lived astatine, have no biological significance. PMID:17991498

Rezanka, Tomás; Sigler, Karel

2008-02-01

295

Effect of mineralogical, geochemical and biological properties on soils reflectance to assess temporal and spatial dynamics of BSCs in Sahelian ecosystems  

NASA Astrophysics Data System (ADS)

Land degradation and desertification are among the major environmental problems, resulting in reduced productivity and development of bare surfaces in arid and semi-arid areas of the world. One important factor that acts to increase soil stability and nutrient content, and thus to prevent water and wind erosion and enhance soil productivity of arid environment, is the presence of biological soil crusts (BSCs). They are the dominant ground cover and a key component of arid environments built up mainly by cyanobacteria. They enhance degraded soil quality by providing a stable and water-retaining substratum and increasing fertility by N and C fixations. The BioCrust project, funded by ANR (VMCS 2008), focuses on BSCs in the Sahelian zone of West Africa (Niger), a highly vulnerable zone facing soil degradation due to the harsh climatic conditions, with variable rainfall, and high anthropic pressure on land use. Unlike arid areas of developed countries (USA, Australia and Israel) or China where BSCs have been extensively studied, studies from Sahelian zone (Africa) are limited (neither the inventory of their different form nor the estimation of their spatial extension has been carried out). The form, structure and composition of BSCs vary depending on characteristics related to soils and biological composition. This study focuses on the soils characterisation using ground-based spectroradiometry. An extensive database was built included spectral measurements on BSCs, bare soils and vegetation that occur in the same area, visual criteria, in situ and laboratory measurements on the physical, chemical and biological characteristics of BSCs and their substratum. The work is carried out on geo-statistical processing of data acquired in sites along a north-south climatic gradient and three types of representative land uses. The investigated areas are highly vulnerable zone facing soil degradation due to the harsh climatic conditions, with variable rainfall, and high anthropic pressure on land use Soil surface disturbances due to the intensification of human activities. Spectral field and laboratory data were acquired in 2009, 2010 and 2011 with the FieldSpec Pro®. The spectra of soils with respect to different parameters are studied in details and their separability from BSCs, vegetation and vegetation residue as well are be analysed. First, the effect of the mineralogy and the geochemical variables on the soil reflectance properties is studied and then the feasibility to resolve some of these effects with satellite imagery (e. g., ASTER) will be tested in order to define the potential capability for identifying the locations of sensitive areas affected by soil degradation and appearance of BSCs.

Bourguignon, A.; Cerdan, O.; Desprats, J. F.; Marin, B.; Malam Issa, O.; Valentin, C.; Rajot, J. L.

2012-04-01

296

The synthetic pyrethroid isomers II. Biological activity  

Microsoft Academic Search

Pure optical isomers of phenothrin, permethin and cypermethrin were synthesised and tested on a wide spectrum of insects (Blattella germanica, Leptinotarsa decemlineata, Tribolium confusum, Oncopeltus fasciatus, Musca domestica, Aedes aegypti). Our results suggest that in the structurally related series phenothrin, permethrin and cypermethrin the chemical modifications had only a small influence on intrinsic activity of the compounds at the target

László Pap; Mária Kelemen; Andrea Tóth; István Székely; Béla Bertók

1996-01-01

297

Biological activity of the humus horizon of ordinary chernozems as an indicator of the ecological state of agroecosystems in Bashkortostan  

NASA Astrophysics Data System (ADS)

A comparative analysis of the biological activity has been performed in the soils of Transural Bashkiria developing under natural perennial grasses and under sown herbs. It is shown that the structure of the microbial community in the soils under natural perennial grasses (fescue, brome grass, and couch grass) prevents the removal of nitrogen from the ecosystem and favors nitrogen fixation in the microbial pool of the trophic chain. The method of multisubstrate testing points to certain differences between the metabolic potentials of the microbial communities of the soils under natural grasses and sown herbs. The high values of the integral index of health of the microbial system in the soils under natural perennial grasses attests to their efficiency in sustaining the soil fertility.

Khasanova, R. F.; Suyundukov, Ya. T.; Semenova, I. N.

2014-08-01

298

Short-term parasite-infection alters already the biomass, activity and functional diversity of soil microbial communities.  

PubMed

Native parasitic plants may be used to infect and control invasive plants. We established microcosms with invasive Mikania micrantha and native Coix lacryma-jobi growing in mixture on native soils, with M. micrantha being infected by parasitic Cuscuta campestris at four intensity levels for seven weeks to estimate the top-down effects of plant parasitism on the biomass and functional diversity of soil microbial communities. Parasitism significantly decreased root biomass and altered soil microbial communities. Soil microbial biomass decreased, but soil respiration increased at the two higher infection levels, indicating a strong stimulation of soil microbial metabolic activity (+180%). Moreover, a Biolog assay showed that the infection resulted in a significant change in the functional diversity indices of soil microbial communities. Pearson correlation analysis indicated that microbial biomass declined significantly with decreasing root biomass, particularly of the invasive M. micrantha. Also, the functional diversity indices of soil microbial communities were positively correlated with soil microbial biomass. Therefore, the negative effects on the biomass, activity and functional diversity of soil microbial community by the seven week long plant parasitism was very likely caused by decreased root biomass and root exudation of the invasive M. micrantha. PMID:25367357

Li, Jun-Min; Jin, Ze-Xin; Hagedorn, Frank; Li, Mai-He

2014-01-01

299

Short-term parasite-infection alters already the biomass, activity and functional diversity of soil microbial communities  

PubMed Central

Native parasitic plants may be used to infect and control invasive plants. We established microcosms with invasive Mikania micrantha and native Coix lacryma-jobi growing in mixture on native soils, with M. micrantha being infected by parasitic Cuscuta campestris at four intensity levels for seven weeks to estimate the top-down effects of plant parasitism on the biomass and functional diversity of soil microbial communities. Parasitism significantly decreased root biomass and altered soil microbial communities. Soil microbial biomass decreased, but soil respiration increased at the two higher infection levels, indicating a strong stimulation of soil microbial metabolic activity (+180%). Moreover, a Biolog assay showed that the infection resulted in a significant change in the functional diversity indices of soil microbial communities. Pearson correlation analysis indicated that microbial biomass declined significantly with decreasing root biomass, particularly of the invasive M. micrantha. Also, the functional diversity indices of soil microbial communities were positively correlated with soil microbial biomass. Therefore, the negative effects on the biomass, activity and functional diversity of soil microbial community by the seven week long plant parasitism was very likely caused by decreased root biomass and root exudation of the invasive M. micrantha. PMID:25367357

Li, Jun-Min; Jin, Ze-Xin; Hagedorn, Frank; Li, Mai-He

2014-01-01

300

Diversity and Activity of Methanotrophic Bacteria in Different Upland Soils  

PubMed Central

Samples from diverse upland soils that oxidize atmospheric methane were characterized with regard to methane oxidation activity and the community composition of methanotrophic bacteria (MB). MB were identified on the basis of the detection and comparative sequence analysis of the pmoA gene, which encodes a subunit of particulate methane monooxygenase. MB commonly detected in soils were closely related to Methylocaldum spp., Methylosinus spp., Methylocystis spp., or the “forest sequence cluster” (USC ?), which has previously been detected in upland soils and is related to pmoA sequences of type II MB (Alphaproteobacteria). As well, a novel group of sequences distantly related (<75% derived amino acid identity) to those of known type I MB (Gammaproteobacteria) was often detected. This novel “upland soil cluster ?” (USC ?) was significantly more likely to be detected in soils with pH values of greater than 6.0 than in more acidic soils. To identify active MB, four selected soils were incubated with 13CH4 at low mixing ratios (<50 ppm of volume), and extracted methylated phospholipid fatty acids (PLFAs) were analyzed by gas chromatography-online combustion isotope ratio mass spectrometry. Incorporation of 13C into PLFAs characteristic for methanotrophic Gammaproteobacteria was observed in all soils in which USC ? sequences were detected, suggesting that the bacteria possessing these sequences were active methanotrophs. A pattern of labeled PLFAs typical for methanotrophic Alphaproteobacteria was obtained for a sample in which only USC ? sequences were detected. The data indicate that different MB are present and active in different soils that oxidize atmospheric methane. PMID:14602631

Knief, Claudia; Lipski, Andre; Dunfield, Peter F.

2003-01-01

301

Instrumental neutron activation analysis of Na in biological materials  

Microsoft Academic Search

Sodium contents in seven mixtures of biological materials from varying aliquants of wheat flour and oyster tissue were analyzed using the INAA (instrumental neutron activation analysis) method. The samples were activated in the thermal column (TC) of the 1 MW TRIGA reactor at our laboratory. To analyze and compare the measured results, the ratioa of the epithermal neutron flux to

L.-Y Sun; M. R. Conrady; R. A. Schmitt

1984-01-01

302

Biologically active traditional medicinal herbs from Balochistan, Pakistan  

Microsoft Academic Search

The biological activities of the following four important medicinal plants of Balochistan, Pakistan were checked; Grewia erythraea Schwein f. (Tiliaceae), Hymenocrater sessilifolius Fisch. and C.A. Mey (Lamiaceae), Vincetoxicum stocksii Ali and Khatoon (Asclepiadaceae) and Zygophyllum fabago L. (Zygophyllaceae). The methanolic extracts were fractionated into hexane, ethyl acetate, chloroform, butanol and water. The antifungal and antibacterial activities of these plants were

Mudassir A. Zaidi; Sidney A. Crow

2005-01-01

303

Biological Effects of Thyrotropin Receptor Activation on Human Orbital Preadipocytes  

Microsoft Academic Search

PURPOSE. Thyrotropin receptor (TSHR) expression is upregu- lated in the orbits of patients with Graves ophthalmopathy (GO), most of whom have TSHR-stimulating antibodies. The authors investigated the biological effects of TSHR activation in vitro in adipose tissue, the site of orbital TSHR expression. METHODS. Activating mutant TSHR (TSHR*) or wild-type (WT) was introduced into human orbital preadipocytes using retro- viral

Lei Zhang; Glynn Baker; Dominika Janus; Carol A. Paddon; Dagmar Fuhrer; Marian Ludgate

2006-01-01

304

Photo-activated biological processes as quantum measurements  

E-print Network

We outline a framework for describing photo-activated biological reactions as generalized quantum measurements of external fields, for which the biological system takes on the role of a quantum meter. By using general arguments regarding the Hamiltonian that describes the measurement interaction, we identify the cases where it is essential for a complex chemical or biological system to exhibit non-equilibrium quantum coherent dynamics in order to achieve the requisite functionality. We illustrate the analysis by considering measurement of the solar radiation field in photosynthesis and measurement of the earth's magnetic field in avian magnetoreception.

Atac Imamoglu; K. Birgitta Whaley

2014-08-21

305

Photo-activated biological processes as quantum measurements  

E-print Network

We outline a framework for describing photo-activated biological reactions as generalized quantum measurements of external fields, for which the biological system takes on the role of a quantum meter. By using general arguments regarding the Hamiltonian that describes the measurement interaction, we identify the cases where it is essential for a complex chemical or biological system to exhibit non-equilibrium quantum coherent dynamics in order to achieve the requisite functionality. We illustrate the analysis by considering measurement of the solar radiation field in photosynthesis and measurement of the earth's magnetic field in avian magnetoreception.

Imamoglu, Atac

2014-01-01

306

Isolation and biological activity of frankiamide  

Microsoft Academic Search

  An antibiotic produced by the symbiotic actinomycete Frankia strain AiPs1 was isolated from culture broth using optimized thin-layer chromatography and high-performance liquid chromatography\\u000a (HPLC) methods. The novel compound that was isolated, dubbed frankiamide, displayed antimicrobial activity against all 14\\u000a Gram-positive bacterial strains and six pathogenic fungal strains tested. The pathogenic actinomycete Clavibacter michiganensis and the ooymycete Phytophthora were especially susceptible.

J P Haansuu; K D Klika; P P Söderholm; V V Ovcharenko; K Pihlaja; K K Haahtela; P M Vuorela

2001-01-01

307

Multielement standards for instrumental neutron activation analysis of biological materials  

Microsoft Academic Search

Standards for instrumental neutron activation analysis (INAA) of biological materials are proposed. The standards are multielement\\u000a solid solutions in phenol-formaldehyde resole resin (PFR) moulded as pellets weighing 30 to 50 mg. The concentrations of trace\\u000a elements in the standards are selected so that, firstly, they are commensurable with their concentrations in the biological\\u000a materials and, secondly, that the analytical lines

L. M. Mosulishvili; M. A. Kolomi'tsev; V. Yu. Dundua; N. I. Shonia; O. A. Danilova

1975-01-01

308

An Inquiry Laboratory Activity for Biology  

NSDL National Science Digital Library

The "cookbook " style approach to studying biochemical reactions mediated by enzymes is changed to an inquiry approach. Cooperative teams are each given two questions about the types of living materials that contain the enzymes that break down hydrogen peroxide, and under what conditions the enzyme works best. They write hypotheses and design and conduct experiments to test these hypotheses. The activity provides students the opportunity to engage in meaningful scientific inquiry because they must truly understand the problem in order to attempt to solve it, to construct meaning in performing experiments, to practice observational skills, and to communicate in writing and in reporting orally to the class on their group results.

Nancy Contolini (Brookfield High School REV)

1994-07-30

309

Impacts of manganese mining activity on the environment: interactions among soil, plants, and arbuscular mycorrhiza.  

PubMed

The mining district of Molango in the Hidalgo State, Mexico, possesses one of the largest deposits of manganese (Mn) ore in the world. This research assessed the impacts of Mn mining activity on the environment, particularly the interactions among soil, plants, and arbuscular mycorrhiza (AM) at a location under the influence of an open Mn mine. Soils and plants from three sites (soil under maize, soil under native vegetation, and mine wastes with some vegetation) were analyzed. Available Mn in both soil types and mine wastes did not reach toxic levels. Samples of the two soil types were similar regarding physical, chemical, and biological properties; mine wastes were characterized by poor physical structure, nutrient deficiencies, and a decreased number of arbuscular mycorrhizal fungi (AMF) spores. Tissues of six plant species accumulated Mn at normal levels. AM was absent in the five plant species (Ambrosia psilostachya, Chenopodium ambrosoides, Cynodon dactylon, Polygonum hydropiperoides, and Wigandia urens) established in mine wastes, which was consistent with the significantly lower number of AMF spores compared with both soil types. A. psilostachya (native vegetation) and Zea mays showed mycorrhizal colonization in their root systems; in the former, AM significantly decreased Mn uptake. The following was concluded: (1) soils, mine wastes, and plant tissues did not accumulate Mn at toxic levels; (2) despite its poor physical structure and nutrient deficiencies, the mine waste site was colonized by at least five plant species; (3) plants growing in both soil types interacted with AMF; and (4) mycorrhizal colonization of A. psilostachya influenced low uptake of Mn by plant tissues. PMID:23124167

Rivera-Becerril, Facundo; Juárez-Vázquez, Lucía V; Hernández-Cervantes, Saúl C; Acevedo-Sandoval, Otilio A; Vela-Correa, Gilberto; Cruz-Chávez, Enrique; Moreno-Espíndola, Iván P; Esquivel-Herrera, Alfonso; de León-González, Fernando

2013-02-01

310

Daily dynamics of the number and activity of nitrogen-fixing bacteria in fallow and intensely cultivated soils  

NASA Astrophysics Data System (ADS)

The daily dynamics (during 33 days) of the number (colony-forming units (CFU)) of nitrogen-fixing bacteria and of the nitrogen-fixing activity (the acetylene method) were determined in a gray forest soil under a fallow land and under an intensely cultivated field. The daily dynamics of the CFUs determined on the nitrogen-free medium in the samples from both plots had wavelike patterns. The daily values of the actual and potential activities of nitrogen fixation in the samples from the fallow land plot and of the actual activity of nitrogen fixation in the samples from the intensely cultivated soil were low and close to the detection limit. The potential activity of nitrogen fixation in the intensely cultivated soil was significant and also had a wavelike pattern. The harmonic analysis of the daily dynamics of the CFUs and nitrogen fixation showed the statistically significant harmonics of these biological characteristics pointing to the objective and regular character of the wavelike dynamics. The revealed dynamics of the biological characteristics of the soils and the methods of their analysis are important in terms of the comparative study of the biological properties of different soils.

Emer, N. R.; Semenov, A. M.; Zelenev, V. V.; Zinyakova, N. B.; Kostina, N. V.; Golichenkov, M. V.

2014-08-01

311

Near infrared spectra are more sensitive to land use changes than physical, chemical and biological soil properties  

Microsoft Academic Search

We studied the sensibility of the near infrared spectra (NIR) of soils to the changes caused by land use, and we compared with the sensibility of different sets of physical, chemical and biological soil properties. For this purpose, we selected three land uses, constituted by forest, almond trees orchards, and orchards abandoned between 10 and 15 years previously to sampling.

C. Guerrero; R. Zornoza; J. Mataix-Solera; J. Mataix-Beneyto; K. Scow

2009-01-01

312

Soil Biology & Biochemistry 38 (2006) 33803386 Short-term C4 plant Spartina alterniflora invasions change the  

E-print Network

Soil Biology & Biochemistry 38 (2006) 3380­3386 Short-term C4 plant Spartina alterniflora invasions change the soil carbon in C3 plant-dominated tidal wetlands on a growing estuarine Island Xiaoli Chenga Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan

Chen, Jiquan

313

TECHNOLOGY EVALUATION REPORT: PILOT-SCALE DEMONSTRATION OF A SLURRY-PHASE BIOLOGICAL REACTOR FOR CREOSOTE-CONTAMINATED SOIL  

EPA Science Inventory

This report documents a pilot-scale test of a slurry-phase biological reactor for treatment of creosote-contaminated soil. he technology used was a reactor system in which an aqueous slurry of soil was mixed with appropriate nutrients and seeded with microorganisms to enhance the...

314

Influence of tillage systems on biological properties of a Typic Argiudoll soil under continuous maize in central Argentina  

Microsoft Academic Search

Farmers are increasingly using zero tillage in Central Argentina to replace other tillage systems. Intensive tillage decreases soil organic matter content and causes physical degradation. The objective of this work was to evaluate changes in some soil biological properties induced by different tillage systems. A 6 year experiment in which continuous maize (Zea mays L.) was grown using three tillage

Alejandro Costantini; Diego Cosentino; Andrea Segat

1996-01-01

315

Biosynthesis, Synthesis and Biological Activities of Pyrrolobenzodiazepines  

PubMed Central

Pyrrolobenzodiazepines (PBDs) are sequence selective DNA alkylating agents with remarkable antineoplastic activity. They are either naturally produced by actinomycetes or synthetically produced. The remarkable broad spectrum of activities of the naturally produced PBDs encouraged the synthesis of several PBDs, including dimeric and hybrid PBDs yielding to an improvement in the DNA binding sequence specificity and in the potency of this class of compounds. However, limitation in the chemical synthesis prevented the testing of one of the most potent PBDs, sibiromycin, a naturally produced glycosylated PBDs. Only recently the biosynthetic gene clusters for PBDs have been identified opening the doors to the production of glycosylated PBDs by mutasynthesis and biosynthetic engineering. The present review describes the recent studies on the biosynthesis of naturally produced pyrrolobenzodiazepines. In addition, it provides an overview on the isolation and characterization of naturally produced PBDs, on the chemical synthesis of PBDs, on the mechanism of DNA alkylation, and on the DNA binding affinity and cytotoxic properties of both naturally produced and synthetic pyrrolobenzodiazepines. PMID:20544978

Gerratana, Barbara

2014-01-01

316

The biological basis of physical activity in children: revisited.  

PubMed

In his seminal paper, Rowland clearly outlined the rationale, evidence, and implications for the biological control of physical activity. Ten years later, there has been some progress in this area related to childhood physical activity with perhaps the greatest progress being made in the areas of genetics and the neuroendocrinology of physical activity. It is clear that heredity contributes to the physical activity (and inactivity) phenotype and candidate genes are now being identified. Furthermore, animal models indicate that maternal exposure to various environmental factors may alter offspring physical activity. Although the mechanisms of this maternal-fetal interaction are unknown, it may involve the development programming of anatomical structures or biophysical pathways involved in energy homeostasis. In this regard, it is also clear that key brain structures and biomolecules involved in motivation, reward, and/or energy balance are also critical to understanding the biological basis of physical activity. Given the potential links between the neuro-endocrine and body composition changes during puberty and the decline in physical activity during this period, future multidisciplinary research in the human child and postnatal animal should be encouraged to provide a better understanding of the biological basis of physical activity during early life. Finally, there are also clear links between between the neuro-endocrine and body composition changes during puberty and the decline in physical activity with psycho-social factors. Thus, there should also be emphasis on understanding the "biocultural" development of the child and its influence on the physical activity phenotype. PMID:19827450

Eisenmann, Joey C; Wickel, Eric E

2009-08-01

317

Field Trial Assessment of Biological, Chemical, and Physical Responses of Soil to Tillage Intensity, Fertilization, and Grazing  

Microsoft Academic Search

Soil microbial populations can fluctuate in response to environmental changes and, therefore, are often used as biological\\u000a indicators of soil quality. Soil chemical and physical parameters can also be used as indicators because they can vary in\\u000a response to different management strategies. A long-term field trial was conducted to study the effects of different tillage\\u000a systems (NT: no tillage, DH:

Silvina Vargas Gil; Analia Becker; Claudio Oddino; Mónica Zuza; Adriana Marinelli; Guillermo March

2009-01-01

318

Identification of Factors Influencing the Restoration of Cyanobacteria-Dominated Biological Soil Crusts  

PubMed Central

Biological soil crusts (BSCs) cover >35% of the Earth’s land area and contribute to important ecological functions in arid and semiarid ecosystems, including erosion reduction, hydrological cycling, and nutrient cycling. Artificial rapid cultivation of BSCs can provide a novel alternative to traditional biological methods for controlling soil and water loss such as the planting of trees, shrubs, and grasses. At present, little is known regarding the cultivation of BSCs in the field due to lack of knowledge regarding the influencing factors that control BSCs growth. Thus, we determined the effects of various environmental factors (shade; watering; N, P, K, and Ca concentrations) on the growth of cyanobacteria-dominated BSCs from the Sonoran Desert in the southwestern United States. The soil surface changes and chlorophyll a concentrations were used as proxies of BSC growth and development. After 4 months, five factors were found to impact BSC growth with the following order of importance: NH4NO3 ? watering frequency>shading>CaCO3 ? KH2PO4. The soil water content was the primary positive factor affecting BSC growth, and BSCs that were watered every 5 days harbored greater biomass than those watered every 10 days. Groups that received NH4NO3 consistently exhibited poor growth, suggesting that fixed N amendment may suppress BSC growth. The effect of shading on the BSC biomass was inconsistent and depended on many factors including the soil water content and availability of nutrients. KH2PO4 and CaCO3 had nonsignificant effects on BSC growth. Collectively, our results indicate that the rapid restoration of BSCs can be controlled and realized by artificial “broadcasting” cultivation through the optimization of environmental factors. PMID:24625498

Bu, Chongfeng; Wu, Shufang; Yang, Yongsheng; Zheng, Mingguo

2014-01-01

319

Identification of factors influencing the restoration of cyanobacteria-dominated biological soil crusts.  

PubMed

Biological soil crusts (BSCs) cover >35% of the Earth's land area and contribute to important ecological functions in arid and semiarid ecosystems, including erosion reduction, hydrological cycling, and nutrient cycling. Artificial rapid cultivation of BSCs can provide a novel alternative to traditional biological methods for controlling soil and water loss such as the planting of trees, shrubs, and grasses. At present, little is known regarding the cultivation of BSCs in the field due to lack of knowledge regarding the influencing factors that control BSCs growth. Thus, we determined the effects of various environmental factors (shade; watering; N, P, K, and Ca concentrations) on the growth of cyanobacteria-dominated BSCs from the Sonoran Desert in the southwestern United States. The soil surface changes and chlorophyll a concentrations were used as proxies of BSC growth and development. After 4 months, five factors were found to impact BSC growth with the following order of importance: NH4NO3 ? watering frequency>shading>CaCO3 ? KH2PO4. The soil water content was the primary positive factor affecting BSC growth, and BSCs that were watered every 5 days harbored greater biomass than those watered every 10 days. Groups that received NH4NO3 consistently exhibited poor growth, suggesting that fixed N amendment may suppress BSC growth. The effect of shading on the BSC biomass was inconsistent and depended on many factors including the soil water content and availability of nutrients. KH2PO4 and CaCO3 had nonsignificant effects on BSC growth. Collectively, our results indicate that the rapid restoration of BSCs can be controlled and realized by artificial "broadcasting" cultivation through the optimization of environmental factors. PMID:24625498

Bu, Chongfeng; Wu, Shufang; Yang, Yongsheng; Zheng, Mingguo

2014-01-01

320

Acid rain and soil microbial activity: effects and their mechanisms  

Microsoft Academic Search

In this investigation, our aim was to determine if acid rain affects soil microbial activity and to identify possible mechanisms of observed effects. A Sierran forest soil (pH 6.4) planted with Ponderosa pine seedlings was exposed to simulated rain (pH 2.0, 3.0, 4.0 and 5.6) with ionic composition reflecting that found in northern California, corresponding to 15 cm of precipitation

K. Killham; M. K. Firestone; J. G. McColl

1983-01-01

321

The NASA Soil Moisture Active Passive (SMAP) mission: Overview  

Microsoft Academic Search

The Soil Moisture Active Passive (SMAP) mission is one of the first Earth observation satellites being developed by NASA in response to the National Research Council's Decadal Survey. Its mission design consists of L-band radiometer and radar instruments sharing a rotating 6-m mesh reflector antenna to provide high-resolution and high-accuracy global maps of soil moisture and freeze\\/thaw state every 2-3

Peggy O'Neill; Dara Entekhabi; Eni G. Njoku; Kent H. Kellogg

2010-01-01

322

A fluorimetric method for measuring the activity of soil enzymes  

Microsoft Academic Search

Summary  A fluorimetric method is described for the measurement of the activity of a range of soil enzymes. The method is based on\\u000a the measurement of 4-methylumbelliferone (MUB), a fluorescent product liberated on hydrolysis of the enzyme substrate. The\\u000a main advantage of the method over colorimetric techniques is that separation of MUB from the soil is unnecessary and the method\\u000a is

P. R. Darrah; P. J. Harris

1986-01-01

323

Soil organic matter dynamics and microbial activity in a cropland and soil treated with wood ash containing charcoal  

NASA Astrophysics Data System (ADS)

Wood ash is generated as a by-product of biomass combustion in power plants, and can be applied to soil to improve nutritional status and crop production. The application of mixed wood ash, a mixture of ash and charcoal, may also improve the SOM content and quality. The charcoal contained in mixed wood ash is a pyrogenic organic material, a heterogeneous mixture of thermally altered polymers with aromatic domains. This structure may favour oxidation, facilitating further microbial attack and generation of new SOM compounds. In addition, accelerated C mineralization of this material may also be due to the priming effect of the rhizosphere, which may even enhance the decomposition of more recalcitrant SOM. The study was carried out in a field devoted to cereal crops during the last few decades. The soil was acidic (pH 4.5) with a low SOC content (3 %). The experiment was based on a randomised block design with four replicates. Each block included the following four treatments: Control, 16 Mg fly wood ash, 16 Mg mixed wood ash and 32 Mg mixed wood ash ha-1. The ash used in the study was obtained from a thermal power plant and was mainly derived from the combustion of Pinus radiata bark. The changes in SOM were monitored over two years by solid state 13C CPMAS NMR and Differential Scanning Calorimetry (DSC). The changes in microbial activity were studied by analysis of microbial biomass C and basal respiration. The soil bacterial community was studied by the Biolog method. Both 13 C-CPMAS NMR spectra and DSC curves revealed that the SOM in the treated soils displayed a higher degree of aromaticity than in the untreated soils, indicating a gain in more stable SOM compounds. However, both methods also revealed increases in other labile C compounds. Microbial biomass and soil respiration increased significantly as a result of these effects and possibly also due to a priming effect. The treatments also led to increases in the functional diversity indices. The amended soils showed greater utilization of substrate and a faster response. The ability of soil bacteria to utilize different C resources was also greatly altered. Greater utilization of carbohydrates, carboxylic acids, amino acid and amines was observed.

Omil, B.; Fonturbel, M. T.; Vega, J. A.; Balboa, M. A.; Merino, A.

2012-04-01

324

Manufacturing of peptides exhibiting biological activity.  

PubMed

Numerous studies have shown that food proteins may be a source of bioactive peptides. Those peptides are encrypted in the protein sequence. They stay inactive within the parental protein until release by proteolytic enzymes (Mine and Kovacs-Nolan in Worlds Poult Sci J 62(1):87-95, 2006; Hartman and Miesel in Curr Opin Biotechnol 18:163-169, 2007). Once released the bioactive peptides exhibit several biofunctionalities and may serve therapeutic roles in body systems. Opioid peptides, peptides lowering high blood pressure, inhibiting platelet aggregation as well as being carriers of metal ions and peptides with immunostimulatory, antimicrobial and antioxidant activities have been described (Hartman and Miesel in Curr Opin Biotechnol 18:163-169, 2007). The biofunctional abilities of the peptides have therefore aroused a lot of scientific, technological and consumer interest with respect to the role of dietary proteins in controlling and influencing health (Möller et al. in Eur J Nutr 47(4):171-182, 2008). Biopeptides may find wide application in food production, the cosmetics industry as well as in the prevention and treatment of various medical conditions. They are manufactured by chemical and biotechnological methods (Marx in Chem Eng News 83(11):17-24. 2005; Hancock and Sahl in Nat Biotechnol 24(12):1551-1557, 2006). Depending on specific needs (food or pharmaceutical industry) different degrees of peptide purifications are required. This paper discusses the practicability of manufacturing bioactive peptides, especially from food proteins. PMID:22914979

Zambrowicz, Aleksandra; Timmer, Monika; Polanowski, Antoni; Lubec, Gert; Trziszka, Tadeusz

2013-02-01

325

Azaglycomimetics: Natural Occurrence, Biological Activity, and Application  

NASA Astrophysics Data System (ADS)

A large number of alkaloids mimicking the structures of monosaccharides or oligosaccharides have been isolated from plants and microorganisms. The sugar mimicking alkaloids with a nitrogen in the ring are called azasugars or iminosugars. Naturally occurring azasugars are classified into five structural classes: polyhydroxylated piperidines, pyrrolidines, indolizidines, pyrrolizidines, and nortropanes. They are easily soluble in water because of their polyhydroxylated structures and inhibit glycosidases because of a structural resemblance to the sugar moiety of the natural substrate. Glycosidases are involved in a wide range of anabolic and catabolic processes, such as digestion, lysosomal catabolism of glycoconjugates, biosynthesis of glycoproteins, and the endoplasmic reticulum (ER) quality control and ER-associated degradation of glycoproteins. Hence, modifying or blocking these processes in vivo by inhibitors is of great interest from a therapeutic point of view. Azasugars are an important class of glycosidase inhibitors and are arousing great interest for instance as antidiabetics, antiobesity drugs, antivirals, and therapeutic agents for some genetic disorders. This review describes the recent studies on isolation, characterization, glycosidase inhibitory activity, and therapeutic application of azaglycomimetics.

Asano, Naoki

326

Rhizosphere activity and methane oxidation in a temperate forest soil  

NASA Astrophysics Data System (ADS)

Methane (CH4) concentrations in the Earth's atmosphere have increased dramatically over recent decades. An abundance of studies indicate that the magnitude of natural methane efflux from wetlands is likely to increase due to climate change. However, the role of vegetation and soils in upland methane oxidation are less well understood. Well-aerated soils are known to be sites of methane oxidation, and amongst a range of abiotic environmental parameters, soil moisture has been identified as critical regulator of the methane oxidation rates. However, the role of microbial activity within the soil, particularly C turnover in the plant rhizosphere, has not been investigated as a means for regulating methanotrophy. We combined a continuous soil CO2 efflux system (Li-Cor Biosciences, LI-8100) with a Cavity-Ringdown-Spectroscopy Fast Greenhouse Gas Analyser (Los Gatos Research Inc.) to measure soil CH4 oxidation in a pine forest in NE England. The soil has a shallow organic layer overlaying a well-draining sandy gley soil. Fluxes were measured from three different collar treatments: (1) excluding both root and ectomycorrhizal (EM) hyphae by trenching using deep collars, (2) excluding roots but allowing access by EM hyphae, and (3) unmodified forest soil (i.e. including both roots and EM hyphae). All collars were protected from natural throughfall, and received weekly-averaged amounts of throughfall based on collections in the stand. Data from two months in early summer 2009 indicate that CH4 oxidation in collars with an intact rhizosphere is more than twice that of either of the exclusion treatments (averaging approx. 90 g ha-1 d-1 in that period). We observed higher fluxes when soils were dryer (i.e. with increasing time since watering), indicating a significant influence of moisture. Despite the confounding effects of soil moisture associated with root water uptake in the unmodified soil collars, we argue that rhizosphere activity is an overlooked component in methanotrophy in aerated soils. C supply from plants by both roots and EM hyphae appears to be linked to the rate at which methanotrophs oxidise methane with potential feedbacks on methane oxidation rates following altered plant productivity driven by climatic change.

Moody, Catherine S.; Subke, Jens-Arne; Voke, Naomi R.; Holden, Robert D.; Ineson, Phil; Arn Teh, Yit

2010-05-01

327

[Biological activity of Penicillium sp. 10-51 exometabolites].  

PubMed

Silica gel column chromatography (silica gel "L" II kind of activity 100/160 mkm) of the chloroform extract from the cultural filtrate of Penicillium sp. 10-51 gave two fractions (chloroform and chloroform-acetone, 5:1) having biological activity. Recrystallization yielded two compounds. On the basis of physico-chemical and spectral data these compounds were identified as curvularin and hydroxycurvularin, which have a large spectrum of biological action as to bacteria, yeast, blue-green algae and phytopathogenic micromycetes. PMID:23088100

Savchuk, Ia I; Za?chenko, A M; Tsyganenko, E S

2012-01-01

328

Fungal Polysaccharides: Biological Activity Beyond the Usual Structural Properties  

PubMed Central

Studies on structure and function of polysaccharides in biological systems classically involve sequence and compositional analyses, anomeric configuration, type of glycosidic linkage, and presence of substituents. Recent studies, however, indicates that other structural parameters, so far little explored, can directly influence the biological activity of microbial polysaccharides. Among these parameters, we highlight the molecular dimensions of Cryptococcus neoformans polysaccharides, which appear to be inversely correlated with their immunobiological activity. These recent observations raise new concepts about the structure and function of polysaccharides, which stimulates the design of new experimental approaches and suggests previously unknown applications. PMID:21886639

Rodrigues, Marcio L.; Nimrichter, Leonardo; Cordero, Radames J. B.; Casadevall, Arturo

2011-01-01

329

Biological Ice Nucleation Activity in Cloud Water (Invited)  

NASA Astrophysics Data System (ADS)

Ice nucleation active (INA) biological particles, in particular microorganisms, were studied in cloud water. Twelve cloud samples were collected over a period of 16 months from the puy de Dôme summit (1465 m, France) using sterile cloud droplet impactors. The samples were characterized through biological (cultures, cell counts) and physico-chemical measurements (pH, ion concentrations, carbon content...), and biological ice nuclei were investigated by droplet-freezing assays from -3°C to -13°C. The concentration of total INA particles within this temperature range typically varied from ~1 to ~100 per mL of cloud water; the concentrations of biological IN were several orders of magnitude higher than the values previously reported for precipitations. At -12°C, at least 76% of the IN were biological in origin, i.e. they were inactivated by heating at 95°C, and at temperatures above -8°C only biological material could induce ice. By culture, 44 Pseudomonas-like strains of bacteria were isolated from cloud water samples; 16% of them were found INA at the temperature of -8°C and they were identified as Pseudomonas syringae, Xanthomonas sp. and Pseudoxanthomonas sp.. Two strains induced freezing at as warm as -2°C, positioning them among the most active ice nucleators described so far. We estimated that, in average, 0.18% and more than 1%.of the bacterial cells present in clouds (~104 mL-1) are INA at the temperatures of -8°C and -12°C, respectively.

Delort, A.

2013-12-01

330

Recent progress in biological activities of synthesized phenothiazines.  

PubMed

This review summarizes recent medicinal chemistry investigations in vitro and in vivo in search for new phenothiazines of promising biological activities. New phenothiazine derivatives (over 50 main structures) contain dialkylaminoalkyl, cycloaminoalkyl and aminoalkyl substituents and their acyl and sulfonyl derivatives, and other substituents with varied the monocyclic (pyrazole, thiazole, oxadiazole, thiadiazole, tetrazole) and bicyclic (quinolizine, pyrazolopyrimidine, thiazolopyridine, azabicyclononane and spiro[chromanpyrimidine] heterocycles linked directly or via the alkyl chain with the thiazine nitrogen atom or with the benzene ring. The modifications of the tricyclic ring system with the bicyclic homoaromatic ring (naphthalene) and monocyclic and bicyclic azine rings (pyridine, pyrimidine, pyrazine and quinoline) led to compounds of significant biological activities. Recently obtained phenothiazines exhibit promising antibacterial, antifungal, anticancer, antiviral, anti-inflammatory, antimalarial, antifilarial, trypanocidal, anticonvulsant, analgesic, immunosuppressive and multidrug resistance reversal properties. These activities were the results of the actions of phenothiazines on biological systems via the interaction of the pharmacophoric substituent (in some cases of strict length), via the interaction of the multicyclic ring system (?-? interaction, intercalation in DNA) and via the lipophilic character allowing the penetration through the biological membranes. The activities were examined by using various biological systems such as cell lines, bacteria, viruses, parasites, laboratory mice, rats and rabbits, and monolayer and bilayer membranes. Some mechanisms of the actions are discussed. This review shows current tendency in the phenothiazine synthesis (without synthetic routes) and reveals the phenothiazine core to be very potent pharmacophoric moiety which can be a rich source of new compounds having desirable biological activities. PMID:21620536

Pluta, Krystian; Morak-M?odawska, Beata; Jele?, Ma?gorzata

2011-08-01

331

Common and distinguishing features of the bacterial and fungal communities in biological soil crusts and shrub root zone soils  

USGS Publications Warehouse

Soil microbial communities in dryland ecosystems play important roles as root associates of the widely spaced plants and as the dominant members of biological soil crusts (biocrusts) colonizing the plant interspaces. We employed rRNA gene sequencing (bacterial 16S/fungal large subunit) and shotgun metagenomic sequencing to compare the microbial communities inhabiting the root zones of the dominant shrub, Larrea tridentata (creosote bush), and the interspace biocrusts in a Mojave desert shrubland within the Nevada Free Air CO2 Enrichment (FACE) experiment. Most of the numerically abundant bacteria and fungi were present in both the biocrusts and root zones, although the proportional abundance of those members differed significantly between habitats. Biocrust bacteria were predominantly Cyanobacteria while root zones harbored significantly more Actinobacteria and Proteobacteria. Pezizomycetes fungi dominated the biocrusts while Dothideomycetes were highest in root zones. Functional gene abundances in metagenome sequence datasets reflected the taxonomic differences noted in the 16S rRNA datasets. For example, functional categories related to photosynthesis, circadian clock proteins, and heterocyst-associated genes were enriched in the biocrusts, where populations of Cyanobacteria were larger. Genes related to potassium metabolism were also more abundant in the biocrusts, suggesting differences in nutrient cycling between biocrusts and root zones. Finally, ten years of elevated atmospheric CO2 did not result in large shifts in taxonomic composition of the bacterial or fungal communities or the functional gene inventories in the shotgun metagenomes.

Steven, Blaire; Gallegos-Graves, La Verne; Yeager, Chris; Belnap, Jayne; Kuske, Cheryl R.

2013-01-01

332

Influence of Soil Moisture on Microbial Activity in a Primary Acidification of Pyritic Soils  

NASA Astrophysics Data System (ADS)

Soil moisture had a grate influence on soil acidification in pyritic soils. The acidification was occurred by chemical and bacterial processes of pyrite oxidation. It was reported that the bacterial oxidation was accelerated by soil moisture at near the condition of plastic limited. We investigated the accelerated soil moisture condition by matric potential and changes of bacterial activity using a soil taken from polder land of the Lake Nakaumi. Six levels of soil moisture conditions were prepared by drying. The samples were incubated at 30oC with keeping these moistures, and populations of Gram-positive and -negative bacteria (GPB and GNB) and Thiobacillus ferrooxidans (total, adsorbed and free forms) were determined. Soil acidification was accelerated at the moisture range from -6.0kPa to -35kPa while drying at 5.4g/h of evaporation rate. Samples drying at 12.0g/h ceased acidifying over -35kPa. On the other hand, a drop of pH value was accelerated at -35kPa when the samples was kept under their moisture conditions. The moisture condition seemed to be suitable for bacterial oxidation. The major bacteria under most of the moisture conditions were GPB, but T. ferrooxidans, one of GNB, was predominated at -35kPa. Under this moisture condition, the growth rate of T. ferrooxidans was highest and the population of GPB decreased during the exponential growth stage of T. ferrooxidans. Acidification of the soil seemed to be depending on proliferation of T. ferrooxidans not on the cell number of T. ferrooxidans. The growth rate of both absorbed and free forms of T. ferrooxidans was highest at -35kPa of all soil moisture conditions. The survival rate of T. ferrooxidans was highest at -3.5kPa and that of the free forms decreased at -35kPa. At -3,000kPa the absorbed forms of T. ferrooxidans had very small population and then decreased. The free forms were not detected. These data indicated that growth habitat of T. ferrooxidans were influenced by soil moisture. The accelerated moisture condition of -35kPa had a uniqueness on the bacterial populations and was suitable for proliferation of T. ferrooxidans. These results showed that high growth rate of T. ferrooxidans had a great influence on high rate of acidification in pyritic soils. The mechanism supposed to be that motility of the bacteria was influenced by shrinkage level of soil matrix and also that the environment was suitable for getting their energy to keep them alive.

Ueno, K.; Adachi, T.

2004-12-01

333

Determination of beta-glucosidase activity in soils with a bioanalytical sensor modified with multiwalled carbon nanotubes.  

PubMed

Soil microorganisms and enzymes are the primary mediators of soil biological processes, including organic matter degradation, mineralization, and nutrient recycling. They play an important role in maintaining soil ecosystem quality and functional diversity. Moreover, enzyme activities can provide an indication of quantitative changes in soil organic matter. Beta-glucosidase (beta-Glu) activity has been found to be sensitive to soil management and has been proposed as a soil quality indicator because it provides an early indication of changes in organic matter status and its turnover. The aims of the present study were to test and use a simple and convenient procedure for the assay of beta-Glu activity in agricultural soil. The method described here is based on the enzymatic degradation of cellobiose by beta-Glu present in the soil sample and the subsequent determination of glucose produced by the enzymatic reaction using screen-printed carbon electrodes modified with multiwalled carbon nanotubes (SPCE-CNT) equipped with coimmobilized glucose oxidase and horseradish peroxidase enzymes. The potential applied to the SPCE-CNT detection was -0.15 V versus a Ag/AgCl pseudo-reference electrode. A linear calibration curve was obtained in the range 2.7-11.3 mM with a correlation coefficient. In the present study, an easy and effective SPCE-CNT-modified electrode allowed an improved amperometric response to be achieved and this is attributed to the increased surface area upon electrode modification. PMID:20349226

Stege, Patricia W; Messina, Germán A; Bianchi, Guillermo; Olsina, Roberto A; Raba, Julio

2010-06-01

334

Molecular and Biological Diagnostic Tests for Monitoring Benzimidazole Resistance in Human Soil-Transmitted Helminths  

PubMed Central

In endemic countries with soil-transmitted helminths mass drug administration with albendazole or mebendazole are being implemented as a control strategy. However, it is well known in veterinary helminths that the use of the same benzimidazole drugs can place selection on the ?-tubulin gene, leading to resistance. Given the concern that resistance could arise in human soil-transmitted helminths, there is an urgent need to develop accurate diagnostic tools for monitoring resistance. In this study, we developed molecular assays to detect putative resistance genetic changes in Ascaris lumbricoides, Trichuris trichiura, and hookworms, and we optimized an egg hatch assay for the canine hookworm Ancylostoma caninum and applied it to Necator americanus. Both assays were tested on field samples. The molecular assays demonstrated their reproducibility and capacity to detect the presence of worms carrying putative resistance-associated genetic changes. However, further investigations are needed to validate our molecular and biological tests on additional field isolates. PMID:23458960

Diawara, Aissatou; Schwenkenbecher, Jan M.; Kaplan, Ray M.; Prichard, Roger K.

2013-01-01

335

Molecular and biological diagnostic tests for monitoring benzimidazole resistance in human soil-transmitted helminths.  

PubMed

In endemic countries with soil-transmitted helminths mass drug administration with albendazole or mebendazole are being implemented as a control strategy. However, it is well known in veterinary helminths that the use of the same benzimidazole drugs can place selection on the ?-tubulin gene, leading to resistance. Given the concern that resistance could arise in human soil-transmitted helminths, there is an urgent need to develop accurate diagnostic tools for monitoring resistance. In this study, we developed molecular assays to detect putative resistance genetic changes in Ascaris lumbricoides, Trichuris trichiura, and hookworms, and we optimized an egg hatch assay for the canine hookworm Ancylostoma caninum and applied it to Necator americanus. Both assays were tested on field samples. The molecular assays demonstrated their reproducibility and capacity to detect the presence of worms carrying putative resistance-associated genetic changes. However, further investigations are needed to validate our molecular and biological tests on additional field isolates. PMID:23458960

Diawara, Aďssatou; Schwenkenbecher, Jan M; Kaplan, Ray M; Prichard, Roger K

2013-06-01

336

Gemini ester quat surfactants and their biological activity.  

PubMed

Cationic gemini surfactants are an important class of surface-active compounds that exhibit much higher surface activity than their monomeric counterparts. This type of compound architecture lends itself to the compound being easily adsorbed at interfaces and interacting with the cellular membranes of microorganisms. Conventional cationic surfactants have high chemical stability but poor chemical and biological degradability. One of the main approaches to the design of readily biodegradable and environmentally friendly surfactants involves inserting a bond with limited stability into the surfactant molecule to give a cleavable surfactant. The best-known example of such a compound is the family of ester quats, which are cationic surfactants with a labile ester bond inserted into the molecule. As part of this study, a series of gemini ester quat surfactants were synthesized and assayed for their biological activity. Their hemolytic activity and changes in the fluidity and packing order of the lipid polar heads were used as the measures of their biological activity. A clear correlation between the hemolytic activity of the tested compounds and their alkyl chain length was established. It was found that the compounds with a long hydrocarbon chain showed higher activity. Moreover, the compounds with greater spacing between their alkyl chains were more active. This proves that they incorporate more easily into the lipid bilayer of the erythrocyte membrane and affect its properties to a greater extent. A better understanding of the process of cell lysis by surfactants and of their biological activity may assist in developing surfactants with enhanced selectivity and in widening their range of application. PMID:23271433

?uczy?ski, Jacek; Fr?ckowiak, Renata; W?och, Aleksandra; Kleszczy?ska, Halina; Witek, Stanis?aw

2013-03-01

337

Impact of interspecific interactions on antimicrobial activity among soil bacteria  

PubMed Central

Certain bacterial species produce antimicrobial compounds only in the presence of a competing species. However, little is known on the frequency of interaction-mediated induction of antibiotic compound production in natural communities of soil bacteria. Here we developed a high-throughput method to screen for the production of antimicrobial activity by monocultures and pair-wise combinations of 146 phylogenetically different bacteria isolated from similar soil habitats. Growth responses of two human pathogenic model organisms, Escherichia coli WA321 and Staphylococcus aureus 533R4, were used to monitor antimicrobial activity. From all isolates, 33% showed antimicrobial activity only in monoculture and 42% showed activity only when tested in interactions. More bacterial isolates were active against S. aureus than against E. coli. The frequency of interaction-mediated induction of antimicrobial activity was 6% (154 interactions out of 2798) indicating that only a limited set of species combinations showed such activity. The screening revealed also interaction-mediated suppression of antimicrobial activity for 22% of all combinations tested. Whereas all patterns of antimicrobial activity (non-induced production, induced production and suppression) were seen for various bacterial classes, interaction-mediated induction of antimicrobial activity was more frequent for combinations of Flavobacteria and alpha- Proteobacteria. The results of our study give a first indication on the frequency of interference competitive interactions in natural soil bacterial communities which may forms a basis for selection of bacterial groups that are promising for the discovery of novel, cryptic antibiotics. PMID:25389421

Tyc, Olaf; van den Berg, Marlies; Gerards, Saskia; van Veen, Johannes A.; Raaijmakers, Jos M.; de Boer, Wietse; Garbeva, Paolina

2014-01-01

338

Biological treatment of soils contaminated with hydrophobic organics using slurry- and solid-phase techniques  

NASA Astrophysics Data System (ADS)

Both slurry-phase and solid-phase bioremediation are effective ex situ soil decontamination methods. Slurrying is energy intensive relative to solid-phase treatment, but provides homogenization and uniform nutrient distribution. Limited contaminant bioavailability at concentrations above the required cleanup level reduces biodegradation rates and renders solid phase bioremediation more cost effective than complete treatment in a bio-slurry reactor. Slurrying followed by solid-phase bioremediation combines the advantages and minimizes the weaknesses of each treatment method when used alone. A biological treatment system consisting of slurrying followed by aeration in solid phase bioreactors was developed and tested in the laboratory using a silty clay loam contaminated with diesel fuel. The first set of experiments was designed to determine the impact of the water content and mixing time during slurrying on the rate an extent of contaminant removal in continuously aerated solid phase bioreactors. The second set of experiments compared the volatile and total diesel fuel removal in solid phase bioreactors using periodic and continuous aeration strategies. Results showed that slurrying for 1.5 hours at a water content less than saturation markedly increased the rate and extent of contaminant biodegradation in the solid phase bioreactors compared with soil having no slurry pretreatment. Slurrying the soil at or above its saturation moisture content resulted in lengthy dewatering times which prohibited aeration, thereby delaying the onset of biological treatment in the solid phase bioreactors. Results also showed that properly operated periodic aeration can provide less volatile contaminant removal and a grater fraction of biological contaminant removal than continuous aeration.

Cassidy, Daniel H.; Irvine, Robert L.

1995-10-01

339

Inedible mushrooms: a good source of biologically active substances  

Microsoft Academic Search

In the course of our investigation on biologically active substances from inedible mushrooms in Japan, Germany, and Vietnam, we studied the chemical constituents of 22 species belonging to five families: Scutigeraceae, Polyporaceae, Xylariaceae, Thelephoraceae, and Paxillaceae. Various types of chemical substances were purified and characterized based on the modern spectro- scopic methods and also on chemical reactions. These metabolites have

Dang Ngoc Quang; Toshihiro Hashimoto; Yoshinori Asakawa

2006-01-01

340

Chemical properties and biological activities of cyclopentenediones: a review.  

PubMed

Cyclopentenediones (CPDs) are secondary metabolites of higher plants, fungi, algae, cyanobacteria and bacteria. A common denominator of CPDs is the cyclopent-4-ene-1,3-dione skeleton (1), which is modified by several functional groups. The heterogeneity of these substitutions is reflected in around one hundred CPDs reported to date. Most of the derivatives were isolated primarily from plant sources. Synthetic analogues were then prepared with new biological activities and more interesting pharmacological potential. Antifungal substances called coruscanones (2, 3) are the most studied of the CPDs. Other intensely investigated CPDs include lucidone (4), linderone (5), asterredione (6), involutone (7), nostotrebin 6 (8), TX-1123 (9), G2201-C (10), madindolines (11, 12) and many others. In addition to antibacterial and antifungal effects, a broad spectrum of biological activities for CPDs has been reported in the past two decades, especially anti-inflammatory, cytostatic and specific enzyme inhibitory activities. The CPD skeleton has been identified in a number of substances isolated from the plant kingdom; hence, CPDs can be referred to as a new group of natural bioactive substances. The main goal of this review is to define CPDs with respect to basic chemistry, isolation, synthetic approaches and description of their biological effects. Special attention is given to a detailed view into biological activities of CPDs in vitro and their phamacological potential. PMID:24605879

Sevcíková, Zuzana; Pour, Milan; Novák, David; Ulrichová, Jitka; Vacek, Jan

2014-04-01

341

Biological activities and corresponding SARs of andrographolide and its derivatives.  

PubMed

In recent years, pharmaceutical chemists have synthesized large numbers of andrographolide derivatives, which bear important biological activities such as anti-inflammatory, antibacterial, antivirus, antitumor, antidiabetic, and antifeedant. Consequently, corresponding SARs were increasingly obvious. This paper aimed to review all the available literature in this field, highlighting the significant achievements on the structural modification and SARs of andrographolide and its derivatives. PMID:23438057

Zhou, Bin; Zhang, Dayong; Wu, Xiaoming

2013-02-01

342

Prescribed Active Learning Increases Performance in Introductory Biology  

ERIC Educational Resources Information Center

We tested five course designs that varied in the structure of daily and weekly active-learning exercises in an attempt to lower the traditionally high failure rate in a gateway course for biology majors. Students were given daily multiple-choice questions and answered with electronic response devices (clickers) or cards. Card responses were…

Freeman, Scott; O'Connor, Eileen; Parks, John W.; Cunningham, Matthew; Hurley, David; Haak, David; Dirks, Clarissa; Wenderoth, Mary Pat

2007-01-01

343

Biological activity of common mullein, a medicinal plant  

Microsoft Academic Search

Common Mullein (Verbascum thapsus L., Scrophulariaceae) is a medicinal plant that has been used for the treatment of inflammatory diseases, asthma, spasmodic coughs, diarrhea and other pulmonary problems. The objective of this study was to assess the biological activity of Common Mullein extracts and commercial Mullein products using selected bench top bioassays, including antibacterial, antitumor, and two toxicity assays—brine shrimp

Arzu Ucar Turker; N. D Camper

2002-01-01

344

BIOLOGICALLY ENHANCED OXYGEN TRANSFER IN THE ACTIVATED SLUDGE PROCESS (JOURNAL)  

EPA Science Inventory

Biologically enhanced oxgyen transfer has been a hypothesis to explain observed oxygen transfer rates in activated sludge systems that were well above that predicted from aerator clean-water testing. The enhanced oxygen transfer rates were based on tests using BOD bottle oxygen ...

345

Smart Sensing Strategies: Insights from a Biological Active Sensing System  

E-print Network

of smart sensing systems in diverse engineering applications. Certain freshwater fish from South America sensing" originated in engineering to describe man-made systems that emit energy into the environment, such as radar and sonar (Bajcsy 1988). An interesting property of biological and man-made active sensing systems

Nelson, Mark E.

346

Biological activities and medicinal properties of neem (Azadirachta indica)  

Microsoft Academic Search

Neem (Azadirachta indica A. Juss) is perhaps the most useful traditional medicinal plant in India. Each part of the neem tree has some medicinal property and is thus commercially exploitable. During the last five decades, apart from the chemistry of the neem com- pounds, considerable progress has been achieved regarding the biological activity and medicinal appli - cations of neem.

Kausik Biswas; Ishita Chattopadhyay; Ranajit K. Banerjee; Uday Bandyopadhyay

347

Influence of biological soil crusts at different successional stages in the implantation of biogeochemical cycles in arid and semiarid zones  

NASA Astrophysics Data System (ADS)

Influence of biological soil crusts at different successional stages in the implantation of biogeochemical cycles in arid and semiarid zones I. Miralles1, F. Gil-Sotres2, Y. Cantón-Castilla3, F. Domingo1, M.C. Leirós2, C. Trasar-Cepeda4 1 Experimental Estation of Arid Zones (CSIC), E-04230 La Cańada de San Urbano, Almería, Spain. 2 Departamento Edafología y Química Agrícola, Grupo de Evaluación de la Calidad del Suelo, Unidad Asociada CSIC, Facultad de Farmacia, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, Spain. 3 University of Almería, Departamento de Edafología y Química Agrícola, E-04230-La Cańada de San Urbano, Almería, Spain. 4 Departamento Bioquímica del Suelo, IIAG-CSIC, Apartado 122, E-15708 Santiago de Compostela, Spain. Crusts (BSCs) are formed by a close association between soil particles and cyanobacteria, algae, lichens, bryophytes and microfungi in varying proportions. Their habitat is within or immediately on top of the uppermost millimetres of the soil and are the predominant surface cover in arid and semiarid zones. Among the diverse functions developed by BSCs in the ecosystem (hydrology, erosion, soil properties, etc.), one of the most important is its role in nutrient cycling. Within arid and semiarid environments, BSCs have been termed 'mantles of fertility' being considered hotspots of biogeochemical inputs, fixing C, N and P above- and below-ground. However, there are differences in N and C fixation rates between BSCs types. Early successional BSCs, dominated by cyanobacterial species, fix lower quantities of C and N than mature BSCs dominated by lichens. Although the positive effects of BSCs on biogeochemical soil cycles are widely accepted, no previous studies have evaluated the activities of the enzymes involved in C, N and P cycles of BSCs and how they are affected by the successional stage of the BSC. In this work, performed in the Tabernas desert (SE Spain), we studied the hydrolase enzymes involved in C (invertase, CM-cellulase, ?-glucosidase), N (urease, BAA-protease, casein-protease) and P (phosphomonoesterase) cycles in BSCs at different successional stages (cyanobacteria represents the first successional stage, lichen Diploschistes diacapsis in an intermediate state and lichen Lepraria crassissima, with the greatest successional state). Our results show that BSCs at lower successional stage enriched the surface geological substrate in hydrolase enzymes to a lesser extent than mature BSCs (Lepraria crassissima), which show the highest values in all enzymatic activities. In contrast, the specific enzyme activities (activity values expressed per unit of carbon) were higher in the BSCs at lower successional stage, decreasing in the direction: cyanobacteria > Diploschistes diacapsis-lichen > Lepraria crassissima-lichen. These results suggest a different role of BSCs depending on their successional stage with regard to the implantation of biogeochemical cycles during the surface substrate colonization. Our conclusions are highly relevant to improve the knowledge of biogeochemical cycles in arid and semiarid areas. Keywords: Biological Soil Crusts, arid ecosystems, hydrolytic enzymes, biochemical activity

Gil-Sotres, F.; Miralles, I.; Canton-Castilla, Y.; Domingo, F.; Leiros, M. C.; Trasar-Cepeda, C.

2012-04-01

348

Diazotrophic Community Structure and Function in Two Successional Stages of Biological Soil Crusts from the Colorado Plateau and Chihuahuan Desert  

USGS Publications Warehouse

The objective of this study was to characterize the community structure and activity of N2-fixing microorganisms in mature and poorly developed biological soil crusts from both the Colorado Plateau and Chihuahuan Desert. Nitrogenase activity was approximately 10 and 2.5 times higher in mature crusts than in poorly developed crusts at the Colorado Plateau site and Chihuahuan Desert site, respectively. Analysis of nifH sequences by clone sequencing and the terminal restriction fragment length polymorphism technique indicated that the crust diazotrophic community was 80 to 90% heterocystous cyanobacteria most closely related to Nostoc spp. and that the composition of N2-fixing species did not vary significantly between the poorly developed and mature crusts at either site. In contrast, the abundance of nifH sequences was approximately 7.5 times greater (per microgram of total DNA) in mature crusts than in poorly developed crusts at a given site as measured by quantitative PCR. 16S rRNA gene clone sequencing and microscopic analysis of the cyanobacterial community within both crust types demonstrated a transition from a Microcoleus vaginatus-dominated, poorly developed crust to mature crusts harboring a greater percentage of Nostoc and Scytonema spp. We hypothesize that ecological factors, such as soil instability and water stress, may constrain the growth of N2-fixing microorganisms at our study sites and that the transition to a mature, nitrogen-producing crust initially requires bioengineering of the surface microenvironment by Microcoleus vaginatus.

Yeager, C.M.; Kornosky, J.L.; Housman, D.C.; Grote, E.E.; Belnap, J.; Kuske, C.R.

2004-01-01

349

Diazotrophic Community Structure and Function in Two Successional Stages of Biological Soil Crusts from the Colorado Plateau and Chihuahuan Desert  

PubMed Central

The objective of this study was to characterize the community structure and activity of N2-fixing microorganisms in mature and poorly developed biological soil crusts from both the Colorado Plateau and Chihuahuan Desert. Nitrogenase activity was approximately 10 and 2.5 times higher in mature crusts than in poorly developed crusts at the Colorado Plateau site and Chihuahuan Desert site, respectively. Analysis of nifH sequences by clone sequencing and the terminal restriction fragment length polymorphism technique indicated that the crust diazotrophic community was 80 to 90% heterocystous cyanobacteria most closely related to Nostoc spp. and that the composition of N2-fixing species did not vary significantly between the poorly developed and mature crusts at either site. In contrast, the abundance of nifH sequences was approximately 7.5 times greater (per microgram of total DNA) in mature crusts than in poorly developed crusts at a given site as measured by quantitative PCR. 16S rRNA gene clone sequencing and microscopic analysis of the cyanobacterial community within both crust types demonstrated a transition from a Microcoleus vaginatus-dominated, poorly developed crust to mature crusts harboring a greater percentage of Nostoc and Scytonema spp. We hypothesize that ecological factors, such as soil instability and water stress, may constrain the growth of N2-fixing microorganisms at our study sites and that the transition to a mature, nitrogen-producing crust initially requires bioengineering of the surface microenvironment by Microcoleus vaginatus. PMID:14766579

Yeager, Chris M.; Kornosky, Jennifer L.; Housman, David C.; Grote, Edmund E.; Belnap, Jayne; Kuske, Cheryl R.

2004-01-01

350

Field Trial Assessment of Biological, Chemical, and Physical Responses of Soil to Tillage Intensity, Fertilization, and Grazing  

NASA Astrophysics Data System (ADS)

Soil microbial populations can fluctuate in response to environmental changes and, therefore, are often used as biological indicators of soil quality. Soil chemical and physical parameters can also be used as indicators because they can vary in response to different management strategies. A long-term field trial was conducted to study the effects of different tillage systems (NT: no tillage, DH: disc harrow, and MP: moldboard plough), P fertilization (diammonium phosphate), and cattle grazing (in terms of crop residue consumption) in maize ( Zea mays L.), sunflower ( Heliantus annuus L.), and soybean ( Glycine max L.) on soil biological, chemical, and physical parameters. The field trial was conducted for four crop years (2000/2001, 2001/2002, 2002/2003, and 2003/2004). Soil populations of Actinomycetes, Trichoderma spp., and Gliocladium spp. were 49% higher under conservation tillage systems, in soil amended with diammonium phosphate (DAP) and not previously grazed. Management practices also influenced soil chemical parameters, especially organic matter content and total N, which were 10% and 55% higher under NT than under MP. Aggregate stability was 61% higher in NT than in MP, 15% higher in P-fertilized soil, and also 9% higher in not grazed strips, bulk density being 12% lower in NT systems compared with MP. DAP application and the absence of grazing also reduced bulk density (3%). Using conservation tillage systems, fertilizing crops with DAP, and avoiding grazing contribute to soil health preservation and enhanced crop production.

Vargas Gil, Silvina; Becker, Analia; Oddino, Claudio; Zuza, Mónica; Marinelli, Adriana; March, Guillermo

2009-08-01

351

[Vertical distribution of soil active carbon and soil organic carbon storage under different forest types in the Qinling Mountains].  

PubMed

Adopting field investigation and indoor analysis methods, the distribution patterns of soil active carbon and soil carbon storage in the soil profiles of Quercus aliena var. acuteserrata (Matoutan Forest, I), Pinus tabuliformis (II), Pinus armandii (III), pine-oak mixed forest (IV), Picea asperata (V), and Quercus aliena var. acuteserrata (Xinjiashan Forest, VI) of Qinling Mountains were studied in August 2013. The results showed that soil organic carbon (SOC), microbial biomass carbon (MBC), dissolved organic carbon (DOC), and easily oxidizable carbon (EOC) decreased with the increase of soil depth along the different forest soil profiles. The SOC and DOC contents of different depths along the soil profiles of P. asperata and pine-oak mixed forest were higher than in the other studied forest soils, and the order of the mean SOC and DOC along the different soil profiles was V > IV > I > II > III > VI. The contents of soil MBC of the different forest soil profiles were 71.25-710.05 mg x kg(-1), with a content sequence of I > V > N > III > II > VI. The content of EOC along the whole soil profile of pine-oak mixed forest had a largest decline, and the order of the mean EOC was IV > V> I > II > III > VI. The sequence of soil organic carbon storage of the 0-60 cm soil layer was V > I >IV > III > VI > II. The MBC, DOC and EOC contents of the different forest soils were significanty correlated to each other. There was significant positive correlation among soil active carbon and TOC, TN. Meanwhile, there was no significant correlation between soil active carbon and other soil basic physicochemical properties. PMID:25223009

Wang, Di; Geng, Zeng-Chao; She, Diao; He, Wen-Xiang; Hou, Lin

2014-06-01

352

Structure and Biological Activities of Beta Toxin from Staphylococcus aureus? †  

PubMed Central

Beta toxin is a neutral sphingomyelinase secreted by certain strains of Staphylococcus aureus. This virulence factor lyses erythrocytes in order to evade the host immune system as well as scavenge nutrients. The structure of beta toxin was determined at 2.4-Ĺ resolution using crystals that were merohedrally twinned. This structure is similar to that of the sphingomyelinases of Listeria ivanovii and Bacillus cereus. Beta toxin belongs to the DNase I folding superfamily; in addition to sphingomyelinases, the proteins most structurally related to beta toxin include human endonuclease HAP1, Escherichia coli endonuclease III, bovine pancreatic DNase I, and the endonuclease domain of TRAS1 from Bombyx mori. Our biological assays demonstrated for the first time that beta toxin kills proliferating human lymphocytes. Structure-directed active site mutations show that biological activities, including hemolysis and lymphotoxicity, are due to the sphingomyelinase activity of the enzyme. PMID:17873030

Huseby, Medora; Shi, Ke; Brown, C. Kent; Digre, Jeff; Mengistu, Fikre; Seo, Keun Seok; Bohach, Gregory A.; Schlievert, Patrick M.; Ohlendorf, Douglas H.; Earhart, Cathleen A.

2007-01-01

353

Rapid and sensitive determination of microbial activity in soils and in soil aggregates by dimethylsulfoxide reduction  

Microsoft Academic Search

Based on the reduction of dimethylusulfoxide (DMSO) to dimethylsulfide (DMS) by microorganisms, a simple, rapid, sensitive and inexpensive method for the determination of microbial activity in soil samples was developed. When DMSO was added to samples, DMS appeared immediately in the gas phase, which was quantitatively analyzed by gas chromatography. The DMS liberation rate was constant for several hours. The

K. Alef; D. Kleiner

1989-01-01

354

Biological soil crust recovery after long-term grazing exclusion in the Monte Desert (Argentina). Changes in coverage, spatial distribution, and soil nitrogen  

NASA Astrophysics Data System (ADS)

Disturbance by domestic grazing is recognized as the most widespread stressor of biological soil crust (BSC) communities. To assess the recovery of the BSC after grazing exclusion, we estimated the composition, cover, and spatial distribution of biological soil crusts, and their influence on soil nitrogen in a protected area after 40 years of grazing exclusion (Reserve MaB of Ńacuńán), and in its surrounding grazed matrix in the central Monte Desert. We considered two spatial scales: at the landscape scale we estimated vegetation and BSC cover in paired grazed and ungrazed sites of Larrea shrublands; at the microsite scale we assessed the influence of the dominant vascular plant, Larrea cuneifolia, on crust cover, and the influence of crust cover on soil nitrogen concentration. Grazing has a negative impact on soil crusts, which only develop under the protection of vascular plants in grazing areas. Grazing exclusion favors crust recovery, allowing black, lichen dominated crusts to develop in exposed areas between shrub canopies. The cover of the moss-dominated crusts was not significantly different at any of the two spatial scales analyzed. Soil nitrogen was higher in areas under L. cuneifolia and without BSC cover, suggesting that litterfall inputs currently exceed those from soil crust N 2 fixation, perhaps because crust function has not yet recovered.

Gómez, Diana A.; Aranibar, Julieta N.; Tabeni, Solana; Villagra, Pablo E.; Garibotti, Irene A.; Atencio, Adrian

2012-01-01

355

The influence of soil heavy metals pollution on soil microbial biomass, enzyme activity, and community composition near a copper smelter  

Microsoft Academic Search

The environmental risk of heavy metal pollution is pronounced in soils adjacent to large industrial complexes. It is important to investigate the functioning of soil microorganisms in ecosystems exposed to long-term contamination by heavy metals. We studied the potential effects of heavy metals on microbial biomass, activity, and community composition in soil near a copper smelter in China. The results

YuanPeng Wang; JiYan Shi; Hui Wang; Qi Lin; XinCai Chen; YingXu Chen

2007-01-01

356

Blending foundry sands with soil: Effect on dehydrogenase activity.  

PubMed

Each year U.S. foundries landfill several million tons of sand that can no longer be used to make metalcasting molds and cores. A possible use for these materials is as an ingredient in manufactured soils; however, potentially harmful metals and resin binders (used to make cores) may adversely impact the soil microbial community. In this study, the dehydrogenase activity (DHA) of soil amended with molding sand (clay-coated sand known as "green sand") or core sands at 10%, 30%, and 50% (dry wt.) was determined. The green sands were obtained from iron, aluminum, and brass foundries; the core sands were made with phenol-formaldehyde or furfuryl alcohol based resins. Overall, incremental additions of these sands resulted in a decrease in the DHA which lasted throughout the 12-week experimental period. A brass green sand, which contained high concentrations of Cu, Pb, and Zn, severely impacted the DHA. By week 12 no DHA was detected in the 30% and 50% treatments. In contrast, the DHA in soil amended with an aluminum green sand was 2.1 times higher (all blending ratios), on average, at week 4 and 1.4 times greater (30% and 50% treatments only) than the controls by week 12. In core sand-amended soil, the DHA results were similar to soils amended with aluminum and iron green sands. Increased activity in some treatments may be a result of the soil microorganisms utilizing the core resins as a carbon source. The DHA assay is a sensitive indicator of environmental stress caused by foundry sand constituents and may be useful to assess which foundry sands are suitable for beneficial use in the environment. PMID:15975632

Dungan, Robert S; Kukier, Urzsula; Lee, Brad

2006-03-15

357

Isolation and characterization of soil Streptomyces species as potential biological control agents against fungal plant pathogens.  

PubMed

The use of antagonist microorganisms against fungal plant pathogens is an attractive and ecologically alternative to the use of chemical pesticides. Streptomyces are beneficial soil bacteria and potential candidates for biocontrol agents. This study reports the isolation, characterization and antagonist activity of soil streptomycetes from the Los Petenes Biosphere Reserve, a Natural protected area in Campeche, Mexico. The results showed morphological, physiological and biochemical characterization of six actinomycetes and their inhibitory activity against Curvularia sp., Aspergillus niger, Helminthosporium sp. and Fusarium sp. One isolate, identified as Streptomyces sp. CACIS-1.16CA showed the potential to inhibit additional pathogens as Alternaria sp., Phytophthora capsici, Colletotrichum sp. and Rhizoctonia sp. with percentages ranging from 47 to 90 %. This study identified a streptomycete strain with a broad antagonist activity that could be used for biocontrol of plant pathogenic fungi. PMID:24310522

Evangelista-Martínez, Zahaed

2014-05-01

358

[Radiometric study of the decarboxylating activity of desert soil microflora].  

PubMed

Employment of growth media containing salts of organic acids, labelled with 14C, gave a rapid and intensive signal concerning the decarboxylating activity of microorganisms from desert soils. The value of the signal was higher than that during the decomposition of uniformly labelled glucose. The results of these studies would help to select the optimal growth medium for carrying out exobiological experiments. PMID:1160646

Imsenecki, A A; Murzakov, B G

1975-01-01

359

Plant Leaf Residue Decomposition, Nutrient Release and Soil Enzyme Activity  

Microsoft Academic Search

We studied the impact of plant leaf residue decompo sition and nutrient release of nitrogen and phosphorus of two weed species - Imperata cylindrica and Chromolaena odorata - and one native forest species - Phyllanthus discoideus - on soil enzyme activities in a pot experiment in the humid tropics of central Cameroon. We tested th e impact of plant leaf

Julia Dux; Lindsey Norgrove; Stefan Hauser; Barbara Wick; Ronald Kühne

360

[Diversity of nitrogen-fixing microorganisms in biological soil crusts of copper mine wastelands].  

PubMed

Biological soil crusts play an important role in increasing the accumulation of organic matter and nitrogen in re-vegetated mining wastelands. The diversity of nitrogen-fixing microorganisms in three types of biological soil crusts (algal crust, moss crust and algal-moss crust) from two wastelands of copper mine tailings were investigated by polymerase chain reaction-denaturing gradient gel electrophoresis, based on the nifH gene of diazotrophs, to investigate: The diversity of nifH gene in the crusts of mine wastelands, and whether and how the nifH gene diversity in the crusts could be affected by the development of plant communities. The algal crust on the barren area displayed the highest nifH gene diversity, followed by the algal-moss crusts within vascular plant communities, and the moss crust displayed the lowest nifH gene diversity. The diversity of diazotrophs in algal-moss crust within vascular plant communities decreased with the increase of height and cover of vascular plant communities. No significant relationship was found between wasteland properties (pH, water content, contents of organic matter, nitrogen and phosphorus and heavy metal concentration) and nifH gene diversity in the crusts. Sequencing and phylogenetic analysis indicated that most nitrogen-fixing taxa in the crusts of mine wastelands belonged to Cyanobacteria, especially nonheterocystous filamentous Cyanobacteria. PMID:25223036

Zhan, Jing; Yang, Gui-De; Sun, Qing-Ye

2014-06-01

361

Temperature sensitivity of microbial respiration, nitrogen mineralization, and potential soil enzyme activities in organic alpine soils  

Microsoft Academic Search

Investigations focusing on the temperature sensitivity of microbial activity and nutrient turnover in soils improve our understanding of potential effects of global warming. This study investigates the temperature sensitivity of C mineralization, N mineralization, and potential enzyme activities involved in the C and N cycle (tyrosine amino-peptidase, leucine amino-peptidase, ß-glucosidase, ß-xylosidase, N-acetyl-ß-glucosaminidase). Four different study sites in the Austrian alpine

Oliver Koch; Dagmar Tscherko; Ellen Kandeler

2007-01-01

362

Models to support active sensing of biological aerosol clouds  

NASA Astrophysics Data System (ADS)

Elastic backscatter LIght Detection And Ranging (LIDAR) is a promising approach for stand-off detection of biological aerosol clouds. Comprehensive models that explain the scattering behavior from the aerosol cloud are needed to understand and predict the scattering signatures of biological aerosols under varying atmospheric conditions and against different aerosol backgrounds. Elastic signatures are dependent on many parameters of the aerosol cloud, with two major components being the size distribution and refractive index of the aerosols. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) has been in a unique position to measure the size distributions of released biological simulant clouds using a wide assortment of aerosol characterization systems that are available on the commercial market. In conjunction with the size distribution measurements, JHU/APL has also been making a dedicated effort to properly measure the refractive indices of the released materials using a thin-film absorption technique and laboratory characterization of the released materials. Intimate knowledge of the size distributions and refractive indices of the biological aerosols provides JHU/APL with powerful tools to build elastic scattering models, with the purpose of understanding, and ultimately, predicting the active signatures of biological clouds.

Brown, Andrea M.; Kalter, Jeffrey M.; Corson, Elizabeth C.; Chaudhry, Zahra; Boggs, Nathan T.; Brown, David M.; Thomas, Michael E.; Carter, Christopher C.

2013-05-01

363

Amazing Soil Stories: Adventure and Activity Book [and] Teacher's Guide to the Activity Book.  

ERIC Educational Resources Information Center

The student activity book offers a variety of written exercises and "hands on" experiments and demonstrations for students at the fourth grade level. The book begins with a cartoon story that follows the adventures of a student investigating a soil erosion crisis and what her community can do to prevent soil erosion. Interspersed within the story…

California Association of Resource Conservation Districts, Sacramento.

364

Effects of soil properties and management on the activity of soil organic matter transforming enzymes and the quantification of soil-bound and free activity  

Microsoft Academic Search

The decomposition of soil organic matter is mediated by extracellular enzymes. The aim of this work was to identify the factors\\u000a determining the activity and size of the mobile fraction of extracellular enzymes (laccase, Mn-peroxidase, endocellulase,\\u000a cellobiohydrolase, ?-glucosidase, endoxylanase, ?-xylosidase, ?-glucosidase, chitinase, arylsulfatase, phosphatase, phosphodiesterase,\\u000a alanine and leucine aminopeptidase) using a set of soils covering a wide range of physico-chemical

Martina Štursová; Petr Baldrian

2011-01-01

365

Soil pH and phosphatase activity  

Microsoft Academic Search

Approximately twenty years before this study, a site that consisted of a mixed oak forest was harvested, cleared, and divided into three treatment areas consisting of approximately 20 acres each. The three areas were planted to oak (forest), grass (grassland) and corn (agricultural) respectively. The influence of pH on the rate of phosphatase activity was determined over a broad range

S. A. Herbien; J. L. Neal

1990-01-01

366

High resolution mapping of Normalized Difference Vegetation Indices (NDVI) of biological soil crusts  

NASA Astrophysics Data System (ADS)

Normalized Difference Vegetation Indices (NDVI) are typically determined using satellite or airborne remote sensing, or field portable spectrometers, which give an averaged signal on centimetre to meter scale plots. Biological soil crust (BSC) patches may have smaller sizes, and ecophysiological, hydrological as well as pedological processes may be heterogeneously distributed within this level of resolution. A ground-based NDVI imaging procedure using low-cost equipment (Olympus Camedia 5000z digital camera equipped with a Hoya R72 infrared filter) was developed in this study to fill this gap at the level of field research, where carrying costly and bulky equipment to remote locations is often the limiting factor for data collection. A commercially available colour rendition chart (GretagMacbeth ColorChecker®) with known red (600-700 nm) and NIR (800-900 nm) reflectances was placed into each scene and used for calibration purposes on a per-image basis. Generation of NDVI images involved (i) determination of red and NIR reflectances from the pixel values of the red and NIR channels, respectively, and (ii) calculation and imaging of the NDVI, where NDVI values of -1 to +1 were mapped to grey values of 0 to 255. The correlation between NDVI values retrieved from these images and NDVI values determined using conventional field spectrometry (ASD FieldSpec 3 portable spectroradiometer) was close (r2 =0.91), the 95% confidence interval amounted to 0.10 NDVI units. The pixel resolution was 0.8 mm in the field and 0.2 mm in the laboratory, but can still be improved significantly with closer distance to the crust or with higher camera resolution. Geostatistical analysis revealed that both spatial variability as well as size of individual objects characterized by the NDVI increased with crust development. The latter never exceeded 4 mm in the investigated crusts, which points to the necessity of high resolution imaging for linking remote sensing with ecophysiology. Perspectively, the new method could be used for field monitoring of both biological soil crusts and vascular vegetation. Literature: Fischer, T., Veste, M., Eisele, A., Bens, O., Spyra, W., Hüttl, R.F. (2012) Small Scale Spatial Heterogeneity of Normalized Difference Vegetation Indices (NDVI) and Hot Spots of Photosynthesis in Biological Soil Crusts. Flora (accepted) DOI: 10.1016/j.flora.2012.01.001 Spröte, R., Fischer, T., Veste, M., Raab, T., Wiehe, W., Lange, P., Bens, O., Hüttl, R.F. (2010): Biological topsoil crusts at early successional stages on Quaternary substrates dumped by mining in Brandenburg, NE Germany. Géomorphologie: relief, processus, environnement 4/2010: 359-370

Fischer, T.; Veste, M.; Eisele, A.; Bens, O.; Spyra, W.; Hüttl, R. F.

2012-04-01

367

Biological activities of xanthatin from Xanthium strumarium leaves.  

PubMed

The objective of the present work was to evaluate the biological activities of the major bioactive compound, xanthatin, and other compounds from Xanthium strumarium (Asteraceae) leaves. Inhibition of bloodstream forms of Trypanosoma brucei brucei and leukaemia HL-60 cell proliferation was assessed using resazurin as a vital stain. Xanthatin was found to be the major and most active compound against T. b. brucei with an IC(50) value of 2.63?µg/mL and a selectivity index of 20. The possible mode of action of xanthatin was further evaluated. Xanthatin showed antiinflammatory activity by inhibiting both PGE(2) synthesis (24% inhibition) and 5-lipoxygenase activity (92% inhibition) at concentrations of 100?µg/mL and 97?µg/mL, respectively. Xanthatin exhibited weak irreversible inhibition of parasite specific trypanothione reductase. Unlike xanthatin, diminazene aceturate and ethidium bromide showed strong DNA intercalation with IC(50) values of 26.04?µg/mL and 44.70?µg/mL, respectively. Substantial induction of caspase 3/7 activity in MIA PaCa-2 cells was observed after 6?h of treatment with 100?µg/mL of xanthatin. All these data taken together suggest that xanthatin exerts its biological activity by inducing apoptosis and inhibiting both PGE(2) synthesis and 5-lipoxygenase activity thereby avoiding unwanted inflammation commonly observed in diseases such as trypanosomiasis. PMID:21953905

Nibret, Endalkachew; Youns, Mahamoud; Krauth-Siegel, R Luise; Wink, Michael

2011-12-01

368

Changes in plant communities along soil pollution gradients: responses of leaf antioxidant enzyme activities and phytochelatin contents.  

PubMed

This work describes an ecological and ecotoxicological study of polluted wasteland plant communities in a former coke-factory located in Homécourt (France). Ecological analyses were performed along two transects to investigate changes in plant community structure through species richness (S), biological diversity (H') and evenness (J). Five species (Arrhenatherum elatius, Bromus tectorum, Euphorbia cyparissias, Hypericum perforatum and Tanacetum vulgare) were then selected to assess cellular responses through antioxidant enzyme activities and phytochelatins (PCs) contents. The results showed that species richness and biological diversity correlated negatively to Cd and Hg concentrations in soil suggesting that soil concentration of non-essential heavy metals was the primary factor governing vegetation structure in the industrial wasteland. Moreover, for all studied species, abundances were partly related to metal levels in the soils, but also to plant antioxidant systems, suggesting their role in plant establishment success in polluted areas. Data for PC contents led to less conclusive results. PMID:19692108

Dazy, Marc; Béraud, Eric; Cotelle, Sylvie; Grévilliot, Frédérique; Férard, Jean-François; Masfaraud, Jean-François

2009-10-01

369

Biological activity in Technosols as a key factor of their structure  

NASA Astrophysics Data System (ADS)

The studies of the dynamics of organic matters within soils, show that their structural stability depends on the biological activity bound to the degradation of organic products. We wondered what it was for Technosols there. We then tried to specify the contribution of this biological activity to the structure of three contrasted technosols : - Technosol 1: a material originated from a former steel industry containing steel and coke residues, which was deposited two years ago in lysimetric plots - Technosol 2: a constructed soil (30 months) resulting from the combination of paper-mill sludge, thermally treated soil material excavated from a former coking plant site, and green-waste compost - Technosol 3: 30 years old technosol developed on flotation ponds of a former steel mill with strong metallic pollution, on which grows a forest ecosystem If these 3 technosols presented initially a similar organic carbon content (around 70 g.kg-1), the origin of organic matters was different A follow-up of the structural stability of these 3 systems, based on techniques of granulometric soil fractionation and morphological/analytical characterization at ultrastructural scale (TEM/EDX), was realized. Results showed the specific contribution of organic matters to the formation of stable organo-mineral associations, in particular those belonging to (0-50 ?m) fraction. They mainly involved organic matter from vegetal origin coming from the spontaneous colonization of these 3 sites, but also from microbial origin corresponding to rhizospheric bacteria producing exopolymers. Organic matters from the compost and cellulosic fibers from the paper-mill sludge also contributed to the formation of organo-mineral associations all the more that compost was also a source of microorganisms. Organic matters were also associated to pollutant metallic elements (Pb, Zn, Mn) initially brought by the materials, then highlighting their possible transfer and questioning about their (bio)availability. HAP also contributed to the aggregation of technogenic constituents in Technosol 1. The biological activity generated by the presence of exogenous organic matter is thus in short (0-2 years) and mean (30 years) terms, a key factor of the structuration and by there of the pedogenesis of Technosols.

Watteau, Françoise; Villemin, Genevičve; Bouchard, Adeline; Monserié, Marie-France; Séré, Geoffroy; Schwartz, Christophe; Morel, Jean-Louis

2010-05-01

370

Biological activities and medicinal properties of Cajanus cajan (L) Millsp.  

PubMed Central

Cajanus cajan (L) Millsp. (Sanskrit: Adhaki, Hindi: Arhar, English: Pigeon pea, Bengali: Tur) (family: Fabaceae) is the most important grain legume crop of rain-fed agriculture in semi-arid tropics. It is both a food crop and a cover/forage crop with high levels of proteins and important amino acids like methionine, lysine and tryptophan. During the last few decades extensive studies have been carried out regarding the chemistry of C. cajan and considerable progress has been achieved regarding its biological activities and medicinal applications. This review article gives an overview on the biological activities of the compounds isolated, pharmacological actions and clinical studies of C. cajan extracts apart from its general details. PMID:22247887

Pal, Dilipkumar; Mishra, Pragya; Sachan, Neetu; Ghosh, Ashoke K.

2011-01-01

371

Marine Omega-3 Phospholipids: Metabolism and Biological Activities  

PubMed Central

The biological activities of omega-3 fatty acids (n-3 FAs) have been under extensive study for several decades. However, not much attention has been paid to differences of dietary forms, such as triglycerides (TGs) versus ethyl esters or phospholipids (PLs). New innovative marine raw materials, like krill and fish by-products, present n-3 FAs mainly in the PL form. With their increasing availability, new evidence has emerged on n-3 PL biological activities and differences to n-3 TGs. In this review, we describe the recently discovered nutritional properties of n-3 PLs on different parameters of metabolic syndrome and highlight their different metabolic bioavailability in comparison to other dietary forms of n-3 FAs. PMID:23203133

Burri, Lena; Hoem, Nils; Banni, Sebastiano; Berge, Kjetil

2012-01-01

372

Occurrence and Biological Activities of Eremophilane-type Sesquiterpenes.  

PubMed

As important members of the terpenes family, sesquiterpenes represent a group of natural compounds with diverse skeletal types. Among them, the eremophilane-type sesquiterpenes, widely present in several genera (such as Ligularia, Senecio, Cacalia) of Asteraceae, account for a small number of natural compounds and form differently from other sesquiterpenes because they challenged the isoprene rule of biosynthesis. Due to the unique structural features and various functional groups, these compounds possess a number of biological activities such as anti-tumor, anti-bacterial and anti-inflammatory, having received increasing interest in the recent years. This review summarizes the occurrence of eremophilane-type sesquiterpenes and research progresses on their biological activities since the 1990s. PMID:25138093

Hou, Chenjie; Kulka, Marianna; Zhang, Junzeng; Li, Yiming; Guo, Fujiang

2014-01-01

373

Biological activities and medicinal properties of Cajanus cajan (L) Millsp.  

PubMed

Cajanus cajan (L) Millsp. (Sanskrit: Adhaki, Hindi: Arhar, English: Pigeon pea, Bengali: Tur) (family: Fabaceae) is the most important grain legume crop of rain-fed agriculture in semi-arid tropics. It is both a food crop and a cover/forage crop with high levels of proteins and important amino acids like methionine, lysine and tryptophan. During the last few decades extensive studies have been carried out regarding the chemistry of C. cajan and considerable progress has been achieved regarding its biological activities and medicinal applications. This review article gives an overview on the biological activities of the compounds isolated, pharmacological actions and clinical studies of C. cajan extracts apart from its general details. PMID:22247887

Pal, Dilipkumar; Mishra, Pragya; Sachan, Neetu; Ghosh, Ashoke K

2011-10-01

374

NASA Soil Moisture Active Passive (SMAP) Mission Formulation  

NASA Technical Reports Server (NTRS)

The Soil Moisture Active Passive (SMAP) Mission is one of the first Earth observation satellites being formulated by NASA in response to the 2007 National Research Council s Earth Science Decadal Survey [1]. SMAP s measurement objectives are high-resolution global measurements of near-surface soil moisture and its freeze-thaw state. These measurements would allow significantly improved estimates of water, energy and carbon transfers between the land and atmosphere. The soil moisture control of these fluxes is a key factor in the performance of atmospheric models used for weather forecasts and climate projections. Soil moisture measurements are also of great importance in assessing flooding and monitoring drought. Knowledge gained from SMAP s planned observations can help mitigate these natural hazards, resulting in potentially great economic and societal benefits. SMAP measurements would also yield high resolution spatial and temporal mapping of the frozen or thawed condition of the surface soil and vegetation. Observations of soil moisture and freeze/thaw timing over the boreal latitudes will contribute to reducing a major uncertainty in quantifying the global carbon balance and help resolve an apparent missing carbon sink over land. The SMAP mission would utilize an L-band radar and radiometer sharing a rotating 6-meter mesh reflector antenna (see Figure 1) [2]. The radar and radiometer instruments would be carried onboard a 3-axis stabilized spacecraft in a 680 km polar orbit with an 8-day repeating ground track. The instruments are planned to provide high-resolution and high-accuracy global maps of soil moisture at 10 km resolution and freeze/thaw at 3 km resolution, every two to three days (see Table 1 for a list of science data products). The mission is adopting a number of approaches to identify and mitigate potential terrestrial radio frequency interference (RFI). These approaches are being incorporated into the radiometer and radar flight hardware and ground processing designs.

Entekhabi, Dara; Njoku, Eni; ONeill, Peggy; Kellogg, Kent; Entin, Jared

2011-01-01

375

Biological Activity and Food Analysis of Cyttaria spp. (Discomycetes)  

Microsoft Academic Search

The biological activity and nutritional composition of Chilean collections ofCyttaria berteroi C. darwinii, C. espinosae, C. harioti andC. johowii have been determined. The crude protein, lipid, ash, and carbohydrate content of the samples examined were similar to that\\u000a of other edible fungi. Amino acid analysis of ChileanCyttaria showed that proteins of all species are deficient in methionine and cysteine and

Guillermo Schmeda-Hirschmann; Ivan Razmilic; Sergio Reyes; Margarita I. Gutierrez; Jose I. Loyola

1999-01-01

376

Isolation of specific cranberry flavonoids for biological activity assessment  

Microsoft Academic Search

Characterisation of cranberry compound biological activity is constrained by limitations in isolation methodology. A single rapid procedure for polyphenolic isolation was developed using semi-preparative-HPLC. Non-flavonoid compounds were removed by pre-purification procedures prior to semi-preparative-HPLC. Fractions were analysed to ascertain purity (99%) with HPLC and ESI mass spectrometric detection in negative ion mode and on-line diode array ultraviolet–visible spectroscopy. Isolated cranberry

Ajay P. Singh; Ted Wilson; Amanda J. Kalk; James Cheong; Nicholi Vorsa

2009-01-01

377

Biological Significance of Local TGF-? Activation in Liver Diseases  

PubMed Central

The cytokine transforming growth factor-? (TGF-?) plays a pivotal role in a diverse range of cellular responses, including cell proliferation, apoptosis, differentiation, migration, adhesion, angiogenesis, stimulation of extracellular matrix (ECM) synthesis, and downregulation of ECM degradation. TGF-? and its receptors are ubiquitously expressed by most cell types and tissues in vivo. In intact adult tissues and organs, TGF-? is secreted in a biologically inactive (latent) form associated in a non-covalent complex with the ECM. In response to injury, local latent TGF-? complexes are converted into active TGF-? according to a tissue- and injury type-specific activation mechanism. Such a well and tightly orchestrated regulation in TGF-? activity enables an immediate, highly localized response to type-specific tissue injury. In the pathological process of liver fibrosis, TGF-? plays as a master profibrogenic cytokine in promoting activation and myofibroblastic differentiation of hepatic stellate cells, a central event in liver fibrogenesis. Continuous and/or persistent TGF-? signaling induces sustained production of ECM components and of tissue inhibitor of metalloproteinase synthesis. Therefore, the regulation of locally activated TGF-? levels is increasingly recognized as a therapeutic target for liver fibrogenesis. This review summarizes our present knowledge of the activation mechanisms and bioavailability of latent TGF-? in biological and pathological processes in the liver. PMID:22363291

Hayashi, Hiromitsu; Sakai, Takao

2012-01-01

378

Biological activities and phytochemicals of Swietenia macrophylla King.  

PubMed

Swietenia macrophylla King (Meliaceae) is an endangered and medicinally important plant indigenous to tropical and subtropical regions of the World. S. macrophylla has been widely used in folk medicine to treat various diseases. The review reveals that limonoids and its derivatives are the major constituents of S. macrophylla. There are several data in the literature indicating a great variety of pharmacological activities of S. macrophylla, which exhibits antimicrobial, anti-inflammatory, antioxidant effects, antimutagenic, anticancer, antitumor and antidiabetic activities. Various other activities like anti-nociceptive, hypolipidemic, antidiarrhoeal, anti-infective, antiviral, antimalarial, acaricidal, antifeedant and heavy metal phytoremediation activity have also been reported. In view of the immense medicinal importance of S. macrophylla, this review aimed at compiling all currently available information on its ethnomedicinal uses, phytochemistry and biological activities of S. macrophylla, showing its importance. PMID:23999722

Moghadamtousi, Soheil Zorofchian; Goh, Bey Hing; Chan, Chim Kei; Shabab, Tara; Kadir, Habsah Abdul

2013-01-01

379

Soil Moisture Active/Passive (SMAP) Mission concept  

NASA Astrophysics Data System (ADS)

Soil Moisture Active/Passive (SMAP) Mission is one of the first satellites being developed by NASA in response to the National Research Council's Decadal Survey. SMAP will make global measurements of the moisture present at Earth's land surface and will distinguish frozen from thawed land surfaces. Direct observations of soil moisture and freeze/thaw state from space will allow better estimates of water and energy transfers between Earth's surface and atmosphere, which are primary driving factors for weather and climate. Soil moisture measurements are also of great importance in assessing flooding potential and as input to flood prediction models. Conversely, observations of widespread low soil moisture levels can provide early warning of drought conditions, reduced water supply and crop loss. SMAP observations can help mitigate these natural hazards, resulting in potentially great economic and social benefits. SMAP freeze/thaw timing observations will also reduce a major uncertainty in quantifying the global carbon balance and will help resolve the problem of the missing carbon sink. The SMAP mission concept would utilize L-band radar and radiometry. These instruments will share a rotating 6-meter mesh antenna to provide high-resolution and high-accuracy global maps of soil moisture and freeze/thaw state every two to three days.

Entekhabi, D.; Jackson, T. J.; Njoku, E.; O'Neill, P.; Entin, J.

2008-08-01

380

Integrity and Biological Activity of DNA after UV Exposure  

NASA Astrophysics Data System (ADS)

The field of astrobiology lacks a universal marker with which to indicate the presence of life. This study supports the proposal to use nucleic acids, specifically DNA, as a signature of life (biosignature). In addition to its specificity to living organisms, DNA is a functional molecule that can confer new activities and characteristics to other organisms, following the molecular biology dogma, that is, DNA is transcribed to RNA, which is translated into proteins. Previous criticisms of the use of DNA as a biosignature have asserted that DNA molecules would be destroyed by UV radiation in space. To address this concern, DNA in plasmid form was deposited onto different surfaces and exposed to UVC radiation. The surviving DNA was quantified via the quantitative polymerase chain reaction (qPCR). Results demonstrate increased survivability of DNA attached to surfaces versus non-adsorbed DNA. The DNA was also tested for biological activity via transformation into the bacterium Acinetobacter sp. and assaying for antibiotic resistance conferred by genes encoded by the plasmid. The success of these methods to detect DNA and its gene products after UV exposure (254 nm, 3.5 J/m2s) not only supports the use of the DNA molecule as a biosignature on mineral surfaces but also demonstrates that the DNA retained biological activity.

Lyon, Delina Y.; Monier, Jean-Michel; Dupraz, Sébastien; Freissinet, Caroline; Simonet, Pascal; Vogel, Timothy M.

2010-04-01

381

Measurements of Microbial Community Activities in Individual Soil Macroaggregates  

SciTech Connect

The functional potential of single soil aggregates may provide insights into the localized distribution of microbial activities better than traditional assays conducted on bulk quantities of soil. Thus, we scaled down enzyme assays for {beta}-glucosidase, N-acetyl-{beta}-D-glucosaminidase, lipase, and leucine aminopeptidase to measure of the enzyme potential of individual aggregates (250-1000 {mu}m diameter). Across all enzymes, the smallest aggregates had the greatest activity and the range of enzyme activities observed in all aggregates supports the hypothesis that functional potential in soil may be distributed in a patchy fashion. Paired analyses of ATP as a surrogate for active microbial biomass and {beta}-glucosidase on the same aggregates suggest the presence of both extracellular {beta}-glucosidase functioning in aggregates with no detectable ATP and also of relatively active microbial communities (high ATP) that have low {beta}-glucosidase potentials. Studying function at a scale more consistent with microbial habitat presents greater opportunity to link microbial community structure to microbial community function.

Bailey, Vanessa L.; Bilskis, Christina L.; Fansler, Sarah J.; McCue, Lee Ann; Smith, Jeff L.; Konopka, Allan

2012-05-01

382

Bromate removal during transition from new granular activated carbon (GAC) to biological activated carbon (BAC)  

Microsoft Academic Search

Bromate removal by activated carbon after ozonation is a subject of concern, since bromate is commonly found in the ozonation of bromide-containing water. Though new GAC (granular activated carbon) shows the capacity to reduce bromate to bromide, in the long-term use of GAC following ozonation, its bromate removal rate apparently decreases during transition from new GAC to BAC (biological activated

Mari Asami; Takako Aizawa; Takayuki Morioka; Wataru Nishijima; Akihisa Tabata; Yasumoto Magara

1999-01-01

383

Water repellency and infiltration of biological soil crusts on an arid and a temperate dunes  

NASA Astrophysics Data System (ADS)

Biological soil crusts (BSCs) play an important role in many ecosystems and in all climates. We studies hydrological properties of BSCs under arid and temperate climates. The arid study site was located near Nizzana, in the northwestern Negev, Israel and the temperate site was near Lieberose, Brandenburg, Germany. BSCs were sampled at each site near the dune crest, at the center of the dune slope and at the dune base. Using principal component analysis (PCA), we studied the relationships between hydraulic properties and the molecular structure of organic matter using repellency indices, microinfiltrometry, and 13C-CP/MAS-NMR. The soil texture was finer and water holding capacities (WHCs) were higher in Nizzana, whereas surface wettability was reduced in Lieberose. At both sites, BSCs caused extra WHC compared to the mineral substrate. Infiltration after wetting along both catenas generally reached a maximum after 10 min and decreased after 30 min. Carbohydrates were the dominating components in all of the BSCs studied, where the relative peak areas of carbohydrate-derived structures (60-110 ppm) amounted to 28-46% and to 10-14% of total C-peak areas, respectively. PCA revealed that the WHC of the substrate was closely related to the amount of silt and clay, whereas the BSC induced extra WHC was closely related to carbohydrates. It was further found that water repellency was positively related to carbohydrate C, but negatively related to alkyl C. Infiltration kinetics was attributed to polysaccharide hydration and swelling. Our findings support the hypothesis that hydraulic properties of BSCs are determined by extracellular polymeric substances (EPS) and soil texture. Hydraulic properties in BSCs result from the combination of chemical properties related to C compounds mainly dominated by carbohydrates and physical surface properties related to texture, porosity and water holding capacity. References Fischer, T., Yair, A., Veste, M., Geppert, H. (2013) Hydraulic properties of biological soil crusts on sand dunes studied by 13C-CP/MAS-NMR: a comparison between an arid and a temperate site. Catena 110:155-160 Breckle, S.-W, Yair, A., Veste, M. (eds.), Arid Dune Ecosystems - The Nizzana Sands in the Negev Desert, Ecological Studies 200, Springer, Berlin Heidelberg New York.

Fischer, Thomas; Yair, Aaron; Geppert, Helmut; Veste, Maik

2014-05-01

384

Chemistry, biological activity, and uses of formamidine pesticides.  

PubMed Central

The formamidines, a relatively new group of acaricide-insecticides, are novel both in their range of biological activities and in their mode of action, which is presently unknown. This paper is a review of the historical development, properties, structures, uses, and chemistry of this group of pesticides, with particular emphasis on chlordimeform (Galecron or Fundal), N'-4-chloro-o-tolyl-N,N-dimethylformamidine, and amitraz, 1,3=di-(2,4-dimethylphenylimino)-2-methyl-2-azapropane. Their biological activity and uses are defined by their toxicity to spider mites, ticks, and certain insects, and they are particularly effective against juvenile and resistant forms of these organisms. A significant, but poorly understood feature of their field effectiveness is their breadth of toxic action which includes direct lethality, excitant-repellant behavioral effects, and chemosterilization. They are generally of low hazard for nontarget species with the significant exception of predaceous mites. Several aspects of the chemistry of these compounds are considered, including structure--activity relations, synthetic pathways, isomerism and configuration, and their chemical and environmental stability. A significant feature of the metabolism and toxicity of these agents is the possible activation of chlordimeform by N-demethylation in vivo. Strong evidence for this has been presented with the cattle tick, but recent results discussed here suggest that in other species, i.e., mice, German cockroaches or black cutworm eggs, N-demethylation is neither a strong activation nor a detoxication reaction. PMID:789070

Hollingworth, R M

1976-01-01

385

The search for life on Mars: Viking 1976 gas changes as indicators of biological activity  

Microsoft Academic Search

Gas compositional changes in the headspace of the Viking Biology Gas Exchange Experiment can originate from biological activity as well as redox chamical reactions, sorption and desorption phenomena, acid-base reactions, and trapped gas release. Biological phenomena are differentiated from the nonbiological gas changes by their dynamical qualities, notably by the ability of the M4 medium to sustain biological activity. Medium

V. I. Oyama; B. J. Berdahl; G. C. Carle; M. E. Lehwalt; H. S. Ginoza

1976-01-01

386

Structure activity relationships: their function in biological prediction  

SciTech Connect

Quantitative structure activity relationships provide a means of ranking or predicting biological effects based on chemical structure. For each compound used to formulate a structure activity model two kinds of quantitative information are required: (1) biological activity and (2) molecular properties. Molecular properties are of three types: (1) molecular shape, (2) physiochemical parameters, and (3) abstract quantitations of molecular structure. Currently the two best descriptors are the hydrophobic parameter, log 1-octanol/water partition coefficient (log P), and the /sup 1/X/sup v/(one-chi-v) molecular connectivity index. Biological responses can be divided into three main categories: (1) non-specific effects due to membrane perturbation, (2) non-specific effects due to interaction with functional groups of proteins, and (3) specific effects due to interaction with receptors. Twenty-six synthetic fossil fuel-related nitrogen-containing aromatic compounds were examined to determine the quantitative correlation between log P and /sup 1/X/sup v/ and population growth impairment of Tetrahymena pyriformis. Nitro-containing compounds are the most active, followed by amino-containing compounds and azaarenes. Within each analog series activity increases with alkyl substitution and ring addition. The planar model log BR = 0.5564 log P + 0.3000 /sup 1/X/sup v/ -2.0138 was determined using mono-nitrogen substituted compounds. Attempts to extrapolate this model to dinitrogen-containing molecules were, for the most part, unsuccessful because of a change in mode of action from membrane perturbation to uncoupling of oxidative phosphoralation.

Schultz, T.W.

1982-01-01

387

Soil moisture regulates the biological response of elevated atmospheric CO 2 concentrations in a coupled atmosphere biosphere model  

Microsoft Academic Search

Terrestrial biosphere models\\/land surface models are routinely used to study the effects of CO2 doubling and climate change. The objective of this study is to show that the biological response associated with CO2 doubling is important, and that the effects intrinsically depend on the soil moisture state. Therefore, using a coupled biosphere–atmosphere model, we tested the hypothesis that the biological

Dev Niyogi; Yongkang Xue

2006-01-01

388

Temporal analysis of the soil microbial community along a toposequence in Pineland soils  

Microsoft Academic Search

The stability and function of a soil ecosystem depends on the cycling of nutrients by the soil microbial community. To evaluate native variability in the functional soil microbial community, temporal changes in microbial community size, activity and metabolic diversity were measured by bacterial population densities, microbial biomass, dehydrogenase activity and metabolic diversity (BIOLOG) assays in native New Jersey Pineland soils.

B. F. Rogers; R. L. Tate

2001-01-01

389

Biological soil crusts are the main contributor to winter soil respiration in a temperate desert ecosystem of China  

NASA Astrophysics Data System (ADS)

Aims Biological soil crusts (BSCs) are a key biotic component of desert ecosystems worldwide. However, most studies carried out to date on carbon (fluxes) in these ecosystems, such as soil respiration (RS), have neglected them. Also, winter RS is reported to be a significant component of annual carbon budget in other ecosystems, however, we have less knowledge about winter RS of BSCs in winter and its contribution to carbon cycle in desert regions. Therefore, the specific objectives of this study were to: (i) quantify the effects of different BSCs types (moss crust, algae crust, physical crust) on the winter RS; (ii) explore relationships of RS against soil temperature and water content for different BSCs, and (iii) assess the relative contribution of BSCs to the annual amount of C released by RS at desert ecosystem level. Methods Site Description The study sites are located at the southeast fringe of the Tengger Desert in the Shapotou region of the Ningxia Hui Autonomous Region [37°32'N and 105°02'E, at 1340 m above mean sea level (a.m.s.l.)], western China. The mean daily temperature in January is -6.9°C , while it is 24.3°C in July. The mean annual precipitation is 186 mm, approximately 80% of which falls between May and September. The annual potential evaporation is 2800 mm. The landscape of the Shapotou region is characterized by large and dense reticulate barchans chains of sand dunes that migrate south-eastward at a velocity of 3-6 m per year. The soil is loose, infertile and mobile and can thus be classified as orthic sierozem and Aeolian sandy soil. Additionally, the soil has a consistent gravimetric water content that ranges from 3 to 4%. The groundwater in the study area is too deep (>60 m) to support large areas of the native vegetation cover; therefore, precipitation is usually the only source of freshwater. The predominant native plants are Hedysarum scoparium Fisch. and Agriophyllum squarrosum Moq., Psammochloa cillosa Bor, which scattered distribute with cover about 1% of the entire study area. Prior to revegetation, straw-checkerboards approximately 1×1 m2 in area were constructed using wheat or rice straw to stabilize the dune surface and allow time for the planted xerophytic shrubs to adapt to the new environment. In 1956, the following 2-year-old xerophytic shrub seedlings were planted within the checkerboard at a density of 16 individuals per 100 m2 and grown without irrigation: Artemisia ordosica Krasch, H. scoparium Fisch, Calligonum mongolicum Turc'z, Caragana microphylla Lam., Caragana korshinskii Kom, Salix gordejevii and Atraphaxis bracteata A.Los. The stabilized area was then expanded to parallel areas in 1964 and 1982 using the same method and species. As a result, the initial stages of change that have occurred at these sites were similar. After more than fifties years succession, the predominant plants are semi-shrubs, shrubs, forbs, and grasses at present and BSCs formed. The common BSCs in the region may be dominated by cyanobacteria, algae, lichens and mosses, or any combination of these organisms. Cyanobacteria species include Microcolous vaginatus Gom., Hydrocoleus violacens Gom., Lyngbya crytoraginatus Schk., Phormidium amblgum Gom., P. autumnale (Ag.) Gom., P. foveolarum (Mont.) Gom. and Phormidium luridum (Kutz) Gom. etc; algal species mainly include Anabaena azotica Ley, Euglena sp., Hantzschia amphioxys var capitata Grum, Oscillatoria obscura Gom., O. pseudogeminate G. Schm. And Scytonema javanicum (Kutz) Bornet Flash etc; lichen species include Collema tenax (Sw.) Ach., Endocarpon pusillum Hedw.; and moss species are dominated by Bryum argenteum Hedw., Didymodon constrictus (Mitt.) Saito., Tortula bidentata Bai Xue Liang and T. desertorum Broth.. Experimental Design and Rs measurements On October 2010, We selected the moss-dominated BSCs at four revegetation sites and natural vegetation sites, in which 3 replicated plots were selected randomly. In each plot, olyvinyl chloride (PVC) collar (lenth 10 cm, internal diameter 10cm ) were inserted 7 cm into the soil. During the

He, M. Z.

2012-04-01

390

Biological activities of oligoketide pigments of Monascus purpureus.  

PubMed

Rubropunctatin (1), monascorubrin (2), monascin (3) and ankaflavin (4) were purified from the mycelium of Monascus purpureus by flash chromatography on silica gel or reversed phase. Their embryotoxicity towards chicken embryos decreased in the order 2 > 1 > 3 > 4. The lower homologues 1 and 3 exhibited teratogenic effects on these organisms. Significant antibiotic activities against Bacillus subtilis and Candida pseudotropicalis were found with compounds 1 and 2. Immunosuppressive activity on mouse T-splenocytes was most pronounced with compounds 3 and 4. None of the compounds showed significant cytotoxic activity towards rat hepatocytes in vitro. Incubation of resting cells of M. purpureus with glycine afforded the dark-red compounds 5 and 6 where the pyran moiety of 1 and 2 changed into the N-substituted dihydropyridine moiety by replacement of the O-atom by the amino group of glycine. Compounds 5 and 6 were less biologically active than the major pigments 1-4. PMID:11565571

Martínková, L; Patáková-J?zlová, P; Krent, V; Kucerová, Z; Havlícek, V; Olsovský, P; Hovorka, O; Ríhová, B; Veselý, D; Veselá, D; Ulrichová, J; Prikrylová, V

1999-01-01

391

Biologically active traditional medicinal herbs from Balochistan, Pakistan.  

PubMed

The biological activities of the following four important medicinal plants of Balochistan, Pakistan were checked; Grewia erythraea Schwein f. (Tiliaceae), Hymenocrater sessilifolius Fisch. and C.A. Mey (Lamiaceae), Vincetoxicum stocksii Ali and Khatoon (Asclepiadaceae) and Zygophyllum fabago L. (Zygophyllaceae). The methanolic extracts were fractionated into hexane, ethyl acetate, chloroform, butanol and water. The antifungal and antibacterial activities of these plants were determined against 12 fungal and 12 bacterial strains by agar well diffusion and disk diffusion assays. The extract of Zygophyllum fabago was found to be highly effective against Candida albicans and Escherichia coli. The extract of Vincetoxicum stocksii was also found to be significantly active against Candida albicans, Bacillus subtilis and Bacillus cereus. Extracts of Hymenocrater sessilifolius and Grewia erythraea showed good activity only against Pseudomonas aeruginosa. PMID:15588685

Zaidi, Mudassir A; Crow, Sidney A

2005-01-01

392

Syntheses and biological activity of C-3'-difluoromethyl-taxoids.  

PubMed

A series of new taxoids bearing difluoromethyl group at the C-3' position and modifications at the C-10 and C-14 positions has been synthesized and their biological activities studied. The in vitro cytotoxicity assay results indicate that these newly developed taxoids exhibit comparable to several times better activity against drug-sensitive cell line LCC6-WT, and 40-70 times better activity against the corresponding drug-resistant cancer cell line LCC6-MDR as compared to that of paclitaxel. Apoptosis analysis has revealed the exceptional activity of SB-T-12843 (1e) in inducing apoptosis in both MDR-bearing and MDR-negative cancer cells. PMID:10976509

Ojima, I; Lin, S; Slater, J C; Wang, T; Pera, P; Bernacki, R J; Ferlini, C; Scambia, G

2000-07-01

393

Natural products as a resource for biologically active compounds  

SciTech Connect

The goal of this study was to investigate various sources of biologically active natural products in an effort to identify the active pesticidal compounds involved. The study is divided into several parts. Chapter 1 contains a discussion of several new compounds from plant and animal sources. Chapter 2 introduces a new NMR technique. In section 2.1 a new technique for better utilizing the lanthanide relaxation agent Gd(fod)/sub 3/ is presented which allows the predictable removal of resonances without line broadening. Section 2.2 discusses a variation of this technique for use in an aqueous solvent by applying this technique towards identifying the binding sites of metals of biological interest. Section 2.3 presents an unambiguous /sup 13/C NMR assignment of melibiose. Chapter 3 deals with work relating to the molting hormone of most arthropods, 20-hydroxyecdysone. Section 3.1 discusses the use of two-dimensional NMR (2D NMR) to assign the /sup 1/H NMR spectrum of this biologically important compound. Section 3.2 presents a new application for Droplet countercurrent chromatography (DCCC). Chapter 4 presents a basic improvement to the commercial DCCC instrument that is currently being applied to future commercial instruments. Chapter 5 discusses a curious observation of the effects that two previously known compounds, nagilactone C and (-)-epicatechin, have on lettuce and rice and suggest a possible new role for the ubiquitous flavanol (-)-epicatechin in plants.

Hanke, F.J.

1986-01-01

394

Preparing for NASA's Soil Moisture Active Passive (SMAP) Mission  

NASA Astrophysics Data System (ADS)

Soil Moisture Active/Passive (SMAP) Mission is one of the first satellites being developed by NASA in response to the National Research Council's Decadal Survey. SMAP will make global measurements of the moisture present at Earth's land surface and will distinguish frozen from thawed land surfaces. Direct observations of soil moisture and freeze/thaw state from space will allow better estimates of water and energy transfers between Earth's surface and atmosphere, which are primary driving factors for weather and climate. Soil moisture measurements are also of great importance in assessing flooding potential and as input to flood prediction models. Conversely, observations of widespread low soil moisture levels can provide early warning of drought conditions, reduced water supply and crop loss. SMAP observations can help mitigate these natural hazards, resulting in potentially great economic and social benefits. SMAP freeze/thaw timing observations will also reduce a major uncertainty in quantifying the global carbon balance and will help resolve the problem of the missing carbon sink. The SMAP mission concept would utilize L-band radar and radiometry. These instruments will share a rotating 6-meter mesh antenna to provide high-resolution and high-accuracy global maps of soil moisture and freeze/thaw state every two to three days. Soil moisture products at 3, 10 and 40 km resolutions will be derived. These will both complement and extend the records of the ESA SMOS mission and offer an order of magnitude improvement in spatial resolution. SMAP is currently in Phase A and scheduled for a 2013 launch. The science teams will be focusing on algorithm development and validation over the next few years. These efforts will be described.

Jackson, T.; Entekhabi, D.; Njoku, E.; O'Neill, P.; Entin, J.

2009-04-01

395

Influence of earthworm invasion on soil microbial biomass and activity in a northern hardwood forest  

Microsoft Academic Search

Recent invasion and activity of exotic earthworms has profoundly altered the chemical and physical environment of surface soils in northern hardwood forests that previously had mor humus horizons. We investigated the influence of earthworm invasion on soil microbial biomass and activity in surface soils of Allegheny northern hardwood forests in central New York state. Earthworm activity in these sites had

Xuyong Li; Melany C Fisk; Timothy J Fahey; Patrick J Bohlen

2002-01-01

396

Effect of anaerobic biological activity on the adsorptive capacity of granular activated carbon  

SciTech Connect

The impact of anaerobic biological activity on the capacity of granular activated carbon (GAC) to adsorb organic compounds has not received much attention. In this study, the capacities of GAC for o-cresol obtained from bottle-point isotherm experiments were compared with the capacities measured in a completely mixed, biologically active, anaerobic GAC reactor treating a high-strength synthetic wastewater containing acetic acid, phenol, and o-cresol. O-cresol was not biodegraded in the reactors and was removed solely by adsorption. Because of the low concentrations of phenol measured in the effluents from the reactors, no competition for adsorption between phenol and o-cresol was observed. Also, the role of biological activity in the regeneration of GAC was demonstrated by preloading GAC with phenol and recovering the adsorbed phenol after the establishment of an active bacterial film on the GAC surface. 30 refs., 5 figs., 2 tabs.

Nakhla, G.F.; Suidan, M.T. [Kinh Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)

1995-11-01

397

Chemistry and biological activity of azoprenylated secondary metabolites.  

PubMed

N-Prenyl secondary metabolites (isopentenylazo-, geranylazo-, farnesylazo- and their biosynthetic derivatives) represent a family of extremely rare natural products. Only in recent years have these alkaloids been recognized as interesting and valuable biologically active secondary metabolites. To date about 35 alkaloids have been isolated from plants mainly belonging to the Rutaceae family, and from fungi, bacteria, and/or obtained by chemical synthesis. These metabolites comprise anthranilic acid derivatives, diazepinones, and indole, and xanthine alkaloids. Many of the isolated prenylazo secondary metabolites and their semisynthetic derivatives are shown to exert valuable in vitro and in vivo anti-cancer, anti-inflammatory, anti-bacterial, anti-viral, and anti-fungal effects. The aim of this comprehensive review is to examine the different types of prenylazo natural products from a chemical, phytochemical and biological perspective. PMID:19660768

Genovese, Salvatore; Curini, Massimo; Epifano, Francesco

2009-06-01

398

Application of activation techniques to biological analysis. [813 references  

SciTech Connect

Applications of activation analysis in the biological sciences are reviewed for the period of 1970 to 1979. The stages and characteristics of activation analysis are described, and its advantages and disadvantages enumerated. Most applications involve activation by thermal neutrons followed by either radiochemical or instrumental determination. Relatively little use has been made of activation by fast neutrons, photons, or charged particles. In vivo analyses are included, but those based on prompt gamma or x-ray emission are not. Major applications include studies of reference materials, and the elemental analysis of plants, marine biota, animal and human tissues, diets, and excreta. Relatively little use of it has been made in biochemistry, microbiology, and entomology, but it has become important in toxicology and environmental science. The elements most often determined are Ag, As, Au, Br, Ca, Cd, Cl, Co, Cr, Cs, Cu, Fe, Hg, I, K, Mn, Mo, Na, Rb, Sb, Sc, Se, and Zn, while few or no determinations of B, Be, Bi, Ga, Gd, Ge, H, In, Ir, Li, Nd, Os, Pd, Pr, Pt, Re, Rh, Ru, Te, Tl, or Y have been made in biological materials.

Bowen, H.J.M.

1981-12-01

399

Inclusion of soil arsenic bioaccessibility in ecological risk assessment and comparison with biological effects.  

PubMed

The purpose of this study was to conduct an ecological risk assessment (ERA) for meadow voles (Microtus pennslvanicus) found at three arsenic contaminated sites in Nova Scotia, Canada (as well as two background locations) and to compare the numeric results to measured biomarkers of exposure and effect. The daily intake of arsenic by meadow voles was determined by three separate calculations: estimated daily intake (EDI), bioaccessible estimated daily intake (BEDI, with bioaccessibility of soil included), and actual daily intake (ADI, which is calculated with arsenic concentrations in the stomach contents). The median bioaccessibility of arsenic in soils from the contaminated locations was significantly greater than at background locations. The bioaccessible arsenic concentration in soil from all samples (both contaminated and background) was significantly less than the total concentration. Use of site-specific bioaccessibility (hazard quotients=38 at Upper Seal Harbour (USH); 60 at Lower Seal Harbour (LSH); and 120 at Montague tailings (MONT)) and stomach arsenic contents (hazard quotients=2.1 at USH; 7.9 at LSH; and 6.7 at MONT) in the ERA resulted in lower numeric risk than compared to risk calculated with 100% bioavailability (hazard quotient=180 at USH; 75 at LSH; and 680 at MONT). Further, the use of bioaccessibility on the calculation of risk was aligned with biomarker results (changes in glutathione and micronucleated erythrocytes) in voles captured at the sites. This study provides evidence that using site-specific bioaccessibility in ERAs may provide a more realistic level of conservatism, thereby enhancing the accuracy of predicting risk to wildlife receptors. Furthermore, when numeric risk assessments are combined with site-specific biological data (i.e., biomarkers of exposure and effect), both lines of evidence can be used to make informed decisions about ecological risk and site management. PMID:22078367

Saunders, Jared R; Knopper, Loren D; Koch, Iris; Reimer, Kenneth J

2011-12-15

400

Estimating the loss of C, N and microbial biomass from Biological Soil Crusts under simulated rainfall  

NASA Astrophysics Data System (ADS)

Most areas where biological soil crusts (BSC) develop undergo a climate with heavy but sparse rainfall events. The hydrological response of the BSC, namely the amount of runoff, is highly variable. Rainfall simulation experiments were conducted in Sadoré, south-western Niger. The aim was to estimate the influence of the BSC coverage on the quantity and quality of water, particles and solutes exported during simulated rainfall events. Ten 1 m2 plots were selected based on their various degree of BSC cover (4-89%) and type of underlying physical crust (structural or erosion crusts). The plots are located on similar sandy soil with moderate slope (3-6%). The experiments consisted of two rainfall events, spaced at 22-hours interval: 60 mm/h for 20 min, and 120 mm/h for 10 min. During each experiments particles dectached and runoff water were collected and filtered in the laboratory. C and N content were determined both in water and sediments samples.. These analyses were completed by measurements of phospholipid fatty acids and chlorophyll a contents in sediments and BSC samples collected before and after the rainfall. Mineral N and microbial biomass carbon of BSC samples were also analysed. The results confirmed that BSC reduce the loss of particles and exert a protective effect on soils with regard to particle detachment by raindrop. However there is no general relationship between the BSC coverage and the loss of C and N due to runoff. Contrarily, the C and N content in the sediments is negatively correlated to their mass. The type of physical crust on which the BSC develop also has to be taken into account. These results will contribute to the region-wide modeling of the role of BSC in biogeochemical cycles.

Gommeaux, M.; Malam Issa, O.; Bouchet, T.; Valentin, C.; Rajot, J.-L.; Bertrand, I.; Alavoine, G.; Desprats, J.-F.; Cerdan, O.; Fatondji, D.

2012-04-01