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1

Soil biological activity at European scale - two calculation concepts  

NASA Astrophysics Data System (ADS)

The CATCH-C project aims to identify and improve the farm-compatibility of Soil Management Practices including to promote productivity, climate change mitigation and soil quality. The focus of this work concentrates on turnover conditions for soil organic matter (SOM). SOM is fundamental for the maintenance of quality and functions of soils while SOM storage is attributed a great importance in terms of climate change mitigation. The turnover conditions depend on soil biological activity characterized by climate and soil properties. To assess the turnover conditions two model concepts are applied: (I) Biological active time (BAT) regression approach derived from CANDY model (Franko & Oelschlägel 1995) expresses the variation of air temperature, precipitation and soil texture as a timescale and an indicator of biological activity for soil organic matter (SOM) turnover. (II) Re_clim parameter within the Introductory Carbon Balance Model (Andrén & Kätterer 1997) states the soil temperature and soil water to estimate soil biological activity. The modelling includes two strategies to cover the European scale and conditions. BAT was calculated on a 20x20 km grid basis. The European data sets of precipitation and air temperature (time period 1901-2000, monthly resolution), (Mitchell et al. 2004) were used to derive long-term averages. As we focus on agricultural areas we included CORINE data (2006) to extract arable land. The resulting BATs under co-consideration of the main soil textures (clay, silt, sand and loam) were investigated per environmental zone (ENZs, Metzger et al. 2005) that represents similar conditions for precipitation, temperature and relief to identify BAT ranges and hence turnover conditions for each ENZ. Re_clim was quantified by climatic time series of more than 250 weather stations across Europe presented by Klein Tank et al. (2002). Daily temperature, precipitation and potential evapotranspiration (maximal thermal extent) were used to calculate soil temperature and water storage in the arable layer thereby differentiating soil textures exclusively in main types (clay, silt, sand and loam). Similar to the BAT investigation it was of further interest to investigate how the re_clim parameter range behaves per ENZ. We will discuss the analyzed results of both strategies in a comparative manner to assess SOM turnover conditions across Europe. Both concepts help to separate different turnover activities and to indicate organic matter input in order to maintain the given SOM. The assessment could provide local recommendations for local adaptations of soil management practices. CATCH-C is funded within the 7th Framework Programme for Research, Technological Development and Demonstration, Theme 2 - Biotechnologies, Agriculture & Food (Grant Agreement N° 289782).

Krüger, Janine; Rühlmann, Jörg

2014-05-01

2

The biological activities of post-agrogenic soils (Based on an Example from the Moscow Region)  

Microsoft Academic Search

Based on the example of soils from the Moscow Region a number of biological activity indicators of arable, virgin, and post-agrogenic\\u000a soils were studied. The lowest indicators of biological activity (potential breathing activity, biomass of microorganisms\\u000a and the relationship between carbon and microorganisms to soil carbon) were shown by arable soils. Among post-agrogenic soils,\\u000a the soils of neglected fields, which

O. Yu. Goncharova; V. M. Telesnina

2010-01-01

3

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 Moyà; Jaume Vadell

2012-01-01

4

Persistence of biologically active compounds in soil: Final report  

SciTech Connect

This document describes the long-term effects of soil-applied oil shale process water on the VA fungi and Rhizobium bacteria in a native soil. Techniques include assessing the VA fungal activity at field treatment plots and using treated field soils in a bioassay to determine VA infection and Rhizobium-nodulation potentials four years after process water application. 52 refs., 32 figs., 2 tabs.

Williams, S.E.

1987-02-01

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.

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

2008-01-01

6

Detection and Investigation of Soil Biological Activity against Meloidogyne incognita.  

PubMed

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 cm(3) 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 cm(3) 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

2008-06-01

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

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

9

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

10

[Soil biological activities at maize seedling stage under application of slow/controlled release nitrogen fertilizers].  

PubMed

With pot experiment and simulating field ecological environment, this paper studied the effects of different slow/ controlled release N fertilizers on the soil nitrate - reductase and urease activities and microbial biomass C and N at maize seedling stage. The results showed that granular urea amended with dicyandiamide (DCD) and N-(n-bultyl) thiophosphoric triamide (NBPT) induced the highest soil nitrate-reductase activity, granular urea brought about the highest soil urease activity and microbial biomass C and N, while starch acetate (SA)-coated granular urea, SA-coated granular urea amended with DCD, methyl methacrylate (MMA) -coated granular urea amended with DCD, and no N fertilization gave a higher soil urease activity. Soil microbial C and N had a similar variation trend after applying various kinds of test slow/controlled release N fertilizers, and were the lowest after applying SA-coated granular urea amended with DCD and NBPT. Coated granular urea amended with inhibitors had a stronger effect on soil biological activities than coated granular urea, and MMA-coating had a better effect than SA-coating. PMID:16964940

Li, Dongpo; Wu, Zhijie; Chen, Lijun; Liang, Chenghua; Zhang, Lili; Wang, Weicheng; Yang, Defu

2006-06-01

11

Biological soil nutrient system  

US Patent & Trademark Office Database

A biological soil nutrient system that combines beneficial soil fungi and bacteria in a growth promoting nutrient medium, embedded in an inorganic porous ceramic particle for direct delivery during soil aerification to the rhizosphere of adventitious plants, including sports turf, landscape and agricultural applications.

2010-12-21

12

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.

Angel, Roey; Matthies, Diethart; Conrad, Ralf

2011-01-01

13

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

Microsoft Academic Search

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

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

2009-01-01

14

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

15

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 (Cerdà 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 (Cerdà 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. Cerdà, 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 Cerdà, A., Giménez-Morera, A.G., Bodí, M.B. 2009b. Soil and water losses from new citrus orchards

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

2014-05-01

16

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

17

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

Microsoft Academic Search

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

Roey Angel; Diethart Matthies; Ralf Conrad; Jack Anthony Gilbert

2011-01-01

18

Potential nitrogen fixation activity of different aged biological soil crusts from rehabilitated grasslands of the hilly Loess Plateau, China  

USGS Publications Warehouse

Biological soil crusts (biocrusts) cover up to 60–70% of the soil surface in grasslands rehabilitated during the "Grain for Green" project implemented in the hilly Loess Plateau region in 1999. As biocrusts fix nitrogen (N), they are an important part of restoring soil fertility. We measured nitrogenase activity (NA) in biocrusts from sites rehabilitated at six different time periods to estimate 1) the effects of moisture content and temperature on NA in biocrusts of different ages and 2) the potential N contribution from biocrusts to soils and plants in this region. Results show that NA in the biocrusts was mostly controlled by the species composition, as the activity of biocrusts dominated by free-living soil cyanobacteria was significantly higher than that of moss-dominated biocrusts. Nitrogenase activity was also influenced by soil moisture content and ambient temperature, with a significant decline in activity when moisture levels were decreased to 20% field water-holding capacity. The optimal temperature for NA was 35–40 °C and 30–40 °C for cyanobacteria- and moss-dominated biocrusts, respectively. Biocrust fixed N is likely an important source of N in this ecosystem, as we estimated annual potential N inputs per hectare in these grasslands to be up to 13 kg N ha-1 and 4 kg N ha-1 for cyanobacteria- and moss-dominated biocrusts, respectively.

Zhao, Y.; Xu, M.; Belnap, J.

2010-01-01

19

Amendments and mulches improve the biological quality of soils degraded by mining activities in SE Spain  

NASA Astrophysics Data System (ADS)

Mining and quarrying activities generate negative visual impacts in the landscape and a loss of environmental quality. Substrate properties at the end of mining are in general not suitable for plant growth, even native ones. In an experimental soil restoration in limestone quarries from Sierra de Gádor (Almería), SE Spain, the effect of organic amendment (sewage sludge, compost from the organic fraction of domestic waste or non-amendment) combined or not with two different kind of mulches (fine gravel, chopped forest residue) was tested by triplicate in 5 x 5 m plots with the aim to improve soil/substrate properties and to reduce evaporation and erosion. In each experimental plot 75 native plants (Stipa tenacissima, Anthyllis terniflora and Anthyllis cytisoides) were planted. Effects of adding organic amendments and mulches on some soil microbiological and biochemical parameters (microbial biomass carbon, basal respiration and different enzymatic activities, such as dehydrogenase, phosphatase, ?-glucosidase and urease) were analyzed 5 years after the start of the experiment. Vegetation growth was also monitored. The two-way ANOVA, using as factors amendment and mulch, showed a significant positive influence of organic amendments on microbial biomass (Cmic), basal respiration and some enzymatic activities related to the cycles of C and N. The highest values of these parameters were obtained with compost. The influence of the mulch factor and its interactions with the amendment factor on the measured variables did not follow a clear trend with respect the measured parameters. Mulching did not improved significantly (p<0.05) the positive effect of organic amendments on Cmic although Cmic values increased with the incorporation of "forest chopped residue" and decreased with gravel incorporation. In general, both type of mulch decreased or have no effect on the microbial activity detected in the amended soils, with the only exception of the forest chopped residue, which increased phosphatase activity in the compost amended soil. Plant growth was significantly higher in amended soils than in the control, but it is remarkable that the mulch type "forest chopped residue" had a negative effect on vegetation growth. The addition of organic amendments, especially compost from the organic fraction of domestic wastes, is beneficial to restore degraded or man-made soils from quarrying areas because they stimulate microbial growth and activity, resulting in mineralization of nutrients necessary for plants and increasing soil fertility and quality. However, after 5 years the effects of the mulch "forest chopped residue", on the improvement of soil or substrate quality are not clear.

Luna Ramos, Lourdes; Miralles Mellado, Isabel; Hernández Fernández, María Teresa; García Izquierdo, Carlos; Solé Benet, Albert

2014-05-01

20

Evaluation of soil compaction effects on soil biota and soil biological processes in soils  

Microsoft Academic Search

Investigations on soil compaction focused mainly on effects on soil physical parameters and on plant growth. Nevertheless, a substantial number of papers deal with effects of soil compaction on soil organisms (soil fauna, soil microorganisms) and biologically driven processes in soils (e.g., macropore formation, respiration rates, N-mineralisation). In view of soil and soil functions protection, there is an essential need

Anneke Beylich; Hans-Rudolf Oberholzer; Stefan Schrader; Heinrich Höper; Berndt-Michael Wilke

2010-01-01

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-Iñigo; 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

Biological properties of soils on mine tips  

NASA Astrophysics Data System (ADS)

The biological properties of soils forming on coalmine spoils composed of loose non-toxic rocks were studied. In ten years of observation, fungal biomass in the studied soils increased by 6 times; the population density of the main groups of bacteria, by 3-7 times, and the respiration intensity, by 5-6 times. The biochemical activity of the soils increased significantly; in particular, the enzymatic activity (especially, the hydrolase activity) increased by 3-8 times, and the processes of cellulose destruction and accumulation of ninhydrinpositive products intensified. The obtained results attest to colonization of the substrate by microorganisms and the development of microbial cenoses. This process is particularly active upon application of phytoameliorants.

Naprasnikova, E. V.

2008-12-01

24

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

25

Aromatic plants play an important role in promoting soil biological activity related to nitrogen cycling in an orchard ecosystem.  

PubMed

Aromatic plants can substantially improve the diversity and structure of arthropod communities, as well as reduce the number of herbivore pests and regulate the abundance of predators and parasitoids. However, it is not clear whether aromatic plants are also effective in improving soil quality by enhancing nutrient cycling. Here, field experiments are described involving intercropping with aromatic plants to investigate their effect on soil nitrogen (N) cycling in an orchard ecosystem. The results indicate that the soil organic nitrogen and available nitrogen contents increased significantly in soils intercropped with aromatic plants. Similarly, the activities of soil protease and urease increased, together with total microbial biomass involved in N cycling, including nitrifying bacteria, denitrifying bacteria and azotobacters, as well as the total numbers of bacteria and fungi. This suggests that aromatic plants improve soil N cycling and nutrient levels by enriching the soil in organic matter through the regulation of both the abundance and community structure of microorganisms, together with associated soil enzyme activity, in orchard ecosystems. PMID:24342101

Chen, Xinxin; Song, Beizhou; Yao, Yuncong; Wu, Hongying; Hu, Jinghui; Zhao, Lingling

2014-02-15

26

Biological Control on Mineral Transformation in Soils ?  

NASA Astrophysics Data System (ADS)

Weathering of primary minerals is commonly linked to biological processes through the production of carbonic and organic acids. Plants can also play a role in weathering by removing soluble constituents and enhancing diffusion gradients within the soil. Here we investigate the synthesis of secondary minerals and the role of plants in removing elements that act as building blocks for these minerals. In order to minimize losses from leaching, we have sampled a chronosequence of soils forming on lava flows on Hawaii Island that receive about 200 mm of rain annually and have never been subjected to high levels of rainfall. The P concentration in the soils drops from almost 3000 mg/kg on a 1.5 ky lava flow to around 1000 mg/kg on a 350 ky lava flow. This loss of P can only be ascribed to P-uptake by plants with subsequent removal through the loss of above ground biomass through fire and/or wind removal. Over the same time frame the amount of plagioclase in the soils drops from around 22% of the <2 mm soil fraction on the youngest lava flow to virtually 0% on the 350 ky flow, suggesting a substantial release of Si. Elevated silicon in arid, basaltic soil environments often leads to formation of smectite, a feature not observed along the chronosequence. In fact, plagioclase is replaced by the kaolin mineral halloysite with allophane as an apparent precursor. Kaolin minerals are associated with moderate to intense leaching environments rather than the mild leaching conditions that influence these soils. We selected an intermediate age soil profile (170 ky lava flow) to conduct an in-depth investigation of the soil mineral composition. We detected a strong dominance of halloysite, the presence of gibbsite, but no smectite. Secondary halloysite formation is preferred over smectite formation when Si activities are relatively low, and the pH is acidic rather than alkaline. Although this mineral assemblage seems to imply formation under a wetter climatic regime, the oxygen isotopic composition of the halloysite suggests formation under soil environmental conditions similar to the present. The Si concentration in grass and tree leaves in the vicinity of the soil contain between 3 and 8% Si. Loss of these leaves to the nearby ocean (either as dried or burned residue) could be responsible for considerable Si removal in a manner similar to the P-removal. The resulting Si-deficient soil-water favors the formation of halloysite over smectite as is demonstrated by construction of mineral stability diagrams using the soil-water data from the soils along the chronosequence.

Ziegler, K.; Hsieh, J. C.; Chadwick, O. A.; Kelly, E. F.

2001-12-01

27

Screening and biological activities of pedopeptins, novel inhibitors of LPS produced by soil bacteria.  

PubMed

Lipopolysaccharide (LPS) is a strong endotoxin and is delivered to the cell surface signaling receptor, Toll-like receptor 4 and MD-2 complex, via soluble cluster of differentiation (CD) 14 or membranous CD14, resulting in the induction of the inflammatory response. To obtain new compounds that block LPS binding to CD14, we designed a high-throughput screening based on time-resolved intermolecular fluorescence resonance energy transfer. This cell-free screening system successfully led to the discovery of novel inhibitors of LPS-CD14 interaction from the library of the secondary metabolites of microorganisms. We identified the novel compounds pedopeptin A, B and C from a culture broth of Pedobacter sp. SANK 72003. Pedopeptins blocked LPS binding to CD14 in vitro with IC50 values of 20, 11 and 47?nM, respectively, and also inhibited LPS binding to the cells expressing CD14, leading to the suppression of cytokine production. Moreover, they showed antimicrobial activities against Escherichia coli with minimum inhibitory concentration ranging from 2 to 4??g ml(-1). PMID:24281661

Kozuma, Shiho; Hirota-Takahata, Yuki; Fukuda, Daisuke; Kuraya, Nahoki; Nakajima, Mutsuo; Ando, Osamu

2014-03-01

28

Long-term effects of intercropping and bio-litter recycling on soil biological activity and fertility status of sub-tropical soils.  

PubMed

On-farm field experiments were carried out at two sites having 38- and 10-year-old orchard cropping systems under sub-tropical climatic regions to evaluate changes in organic carbon accumulation and chemical and microbiological properties of the soils. Under a system of different intercropped fruit trees, the cultivation of coconut (Cocos nucifera L.) intercropped with guava (Psidium guajava L.) enhanced the soil microbial activity approximately 2-fold after 38 yrs over 10 yrs of the same intercropped system. Soil organic carbon increased from 3.4 to 7.8 and 2.4 to 6.2 g kg-1 after 38 and 10 yrs, respectively, following the establishment of orchards. The increase was attributed to greater recycling of bio-litters. Levels of dehydrogenase, phosphatase and soil microbial biomass under field conditions generally depended more on the nature of the cropping system than on soil types. Similarly, average carbon inputs of bio-litter to the soil in monocrop (0.98 Mg ha-1 yr-1) was less than intercropped fruit trees (2.07 Mg ha-1 yr-1). The average level of soil microbial biomass carbon was 1158 kg ha-1 (0-0.15 m depth) and the organic carbon turnover rate was 8.5 yr-1 after 38 yrs of intercropped fruit trees, which resulted in a lower ratio (1.81) of carbon inputs to soil microbial biomass carbon. PMID:11131798

Manna, M C; Singh, M V

2001-01-01

29

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

30

Soil microbial activity and a free-living nematode community in the playa and in the sandy biological crust of the Negev Desert  

Microsoft Academic Search

The effect of environmental factors and soil properties on microbial and soil free-living nematode communities was investigated\\u000a in two desert soil formations, a playa and sandy biological crust. Soil samples were collected from October 2007 to September\\u000a 2008 from the upper (0–10 cm) soil layers in the Negev Desert area. Unlike microorganisms, soil free-living nematodes were\\u000a found to be negatively dependent

Stanislav Pen-Mouratov; Cheng Hu; Etan Hindin; Yosef Steinberger

2011-01-01

31

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

32

Biological activities of pyridoacridines.  

PubMed

This review consolidates biological activity data reported for pyridoacridine 1 molecules in the literature from 1983-2003 into several tables with brief discussions of assays used and results obtained. This review summarizes recent progress in structure activity relationships for analogues of amphimedine 2 and ascididemin 3 classes of pyridoacridines and correlates reported molecular mechanisms of action with biological activities. PMID:15565252

Marshall, Kathryn M; Barrows, Louis R

2004-12-01

33

Behavior of oxyfluorfen in soils amended with different sources of organic matter. Effects on soil biology.  

PubMed

We performed a laboratory study on the effect of oxyfluorfen at a rate of 4lha(-1) on biological properties of a soil amended with four organic wastes (two biostimulants/biofertilizers, obtained from rice bran, RB1 and RB2; municipal solid waste, MSW; and sheep manure, SM). Soil was mixed with SM at a rate of 1%, MSW at a rate of 0.52%, RB1 at a rate of 0.39% and RB2 at a rate of 0.30%, in order to apply the same amount of organic matter to the soil. The enzymatic activities and microbial community in the soil were determined during the incubation times. The application of RB1 and RB2 to soil without oxyfluorfen increased the enzymatic activities and biodiversity, peaking at day 10 of the incubation period. This stimulation was higher in the soil amended with RB2 than in that amended with RB1. In SM and CF-amended soils, the stimulation of enzymatic activities and soil biodiversity increased during the experiment. 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 and the higher fat content in the biostimulants/biofertilizers are responsible for the lower inhibition of these soil biological properties. PMID:24742665

Gómez, Isidoro; Rodríguez-Morgado, Bruno; Parrado, Juan; García, Carlos; Hernández, Teresa; Tejada, Manuel

2014-05-30

34

Genetic Diversity and Biological Control Activity of Novel Species of Closely Related Pseudomonads Isolated from Wheat Field Soils in South Australia  

PubMed Central

Rhizobacteria closely related to two recently described species of pseudomonads, Pseudomonas brassicacearum and Pseudomonas thivervalensis, were isolated from two geographically distinct wheat field soils in South Australia. Isolation was undertaken by either selective plating or immunotrapping utilizing a polyclonal antibody raised against P. brassicacearum. A subset of 42 isolates were characterized by amplified 16S ribosomal DNA restriction analysis (ARDRA), BIOLOG analysis, and gas chromatography-fatty acid methyl ester (GC-FAME) analysis and separated into closely related phenetic groups. More than 75% of isolates tested by ARDRA were found to have >95% similarity to either Pseudomonas corrugata or P. brassicacearum-P. thivervalensis type strains, and all isolates had >90% similarity to either type strain. BIOLOG and GC-FAME clustering showed a >70% match to ARDRA profiles. Strains representing different ARDRA groups were tested in two soil types for biological control activity against the soilborne plant pathogen Gaeumannomyces graminis var. tritici, the causative agent of take-all of wheat and barley. Three isolates out of 11 significantly reduced take-all-induced root lesions on wheat plants grown in a red-brown earth soil. Only one strain, K208, was consistent in reducing disease symptoms in both the acidic red-brown earth and a calcareous sandy loam. Results from this study indicate that P. brassicacearum and P. thivervalensis are present in Australian soils and that a level of genetic diversity exists within these two novel species but that this diversity does not appear to be related to geographic distribution. The result of the glasshouse pot trial suggests that some isolates of these species may have potential as biological control agents for plant disease.

Ross, Ian L.; Alami, Younes; Harvey, Paul R.; Achouak, Wafa; Ryder, Maarten H.

2000-01-01

35

[Effects of biological soil crust on soil erodibility in Hilly Loess Plateau region of Northwest China].  

PubMed

Based on the analysis of the effects of biological soil crust (biocrust) in re-vegetated grasslands on soil physical and chemical properties, and by using EPIC estimation model in combining with simulated rainfall trials, this paper studied the effects of biocrust with different biomass and different soil texture on the soil erodibility (K value) in Hilly Loess Plateau Region of Northwest China in different seasons. The results showed biocrust could significantly decrease soil erodibility, with the K value of biocrust soil decreased by about 17%, compared with subsoil. The soil erodibility decreased with the increasing biomass of biocrust. The K value of moss crust soil decreased by 21%, compared with cyanobacteria crust soil. The erodibiliy of biocrust soil differed with different seasons, being significantly higher in rainy season than before or after the rainy season due to the differences in the biological activity of the biocrust organisms. The erodibilty of biocrust soil with different texture also varied significantly, with the K value in the order of sandy loam soil > silt soil > sandy soil. The measurement under simulated rainfall showed that the development of biocrust could decrease the erodibility of biocrust soil by about 90%, compared with that of the subsoil (5-10 cm). PMID:23717997

Gao, Li-Qian; Zhao, Yun-Ge; Qin, Ning-Qiang; Zhang, Guo-Xiu

2013-01-01

36

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

Microsoft Academic Search

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

S. R. Wild; K. C. Jones

1993-01-01

37

Metadata Activities in Biology  

SciTech Connect

The National Biological Information Infrastructure program has advanced the biological sciences ability to standardize, share, integrate and synthesize data by making the metadata program a core of its activities. Through strategic partnerships, a series of crosswalks for the main biological metadata specifications have enabled data providers and international clearinghouses to aggregate and disseminate tens of thousands of metadata sets describing petabytes of data records. New efforts at the National Biological Information Infrastructure are focusing on better metadata creation and curation tools, semantic mediation for data discovery and other curious initiatives.

Inigo, Gil San [University of New Mexico, Albuquerque; HUTCHISON, VIVIAN [USGS; Frame, Mike [USGS; Palanisamy, Giri [ORNL

2010-01-01

38

Structure and Reactivity of a Biological Soil Crust from a Xeric Sandy Soil in Central Europe  

Microsoft Academic Search

The investigation was designed to explore the structure, composition, and activity of a biological soil crust on an acidic, sandy soil from a temperate climate. The crust covers several hundreds of square meters on the hilltop of a large terminal moraine. The conjugate alga Zygogonium ericetorum forms the essential matrix for the crust, a dense web of algal filaments with

Michael Hoppert; Rudolph Reimer; Anne Kemmling; Annekatrin Schröder; Bettina Günzl; Thilo Heinken

2004-01-01

39

Biological Activity of Allergens.  

National Technical Information Service (NTIS)

The biologic activity of allergenic extracts can be measured by quantitative skin testing and by histamine release from peripheral leucocytes of sensitive individuals. Both of these tests have been shown to correlate with the concentrations of the most im...

P. S. Norman

1976-01-01

40

Development of biological soil disinfestations in Japan.  

PubMed

Biological soil disinfestations (BSDs) were developed separately in Japan and in The Netherlands as an alternative to chemical fumigations. In Japan, it was developed based on the knowledge of irrigated paddy rice and upland crop rotation system that was rather tolerant of soil-borne disease development. The methods consist of application of easily decomposable organic matter, irrigation, and covering the soil surface with plastic film, thereby inducing anaerobic (reductive) soil conditions and suppressing many soil-borne pests including fungi, bacteria, nematodes, and weeds. The methods are widely used by organic farmers in the area where residences and agricultural fields are intermingled. To note one advantage of these methods, maintenance of soil suppressiveness to Fusarium wilt of tomato was suggested, while soil treated with chloropicrin became conducive to the disease. Suppression of soil-borne fungal pathogens by BSDs might be attributed to anaerobicity and high temperature, organic acids generated, and metal ions released into soil water. Contributions of respective factors to suppression of respective pathogens might be diverse. Presumably, these factors might vary on the fungal community structure in BSD-treated soil. These factors also work in paddy fields. Therefore, the BSDs developed in Japan are probably a method to raise the efficacy of paddy-upland rotation through intensive organic matter application and through maintenance of a strongly anaerobic (reductive) soil condition. PMID:23549745

Momma, Noriaki; Kobara, Yuso; Uematsu, Seiji; Kita, Nobuhiro; Shinmura, Akinori

2013-05-01

41

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

PubMed

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 isolates belonging to the Nocardiopsis genus and 32 isolates belonging to the Saccharothrix genus. An assessment of the antimicrobial properties of the isolates showed activities against Gram-positive bacteria, fungi and yeasts. Saccharothrix isolates possessed better antifungal activity than Nocardiopsis. One of them, labeled SA 103, was therefore selected for identification of its antifungal antibiotic activities. Production of overall antifungal and antibacterial activities was checked on the complex medium ISP2 and a synthetic medium (SM) that contains glucose or starch as carbon source, and ammonium or nitrate as nitrogen source. The SM medium containing ammonium sulfate (0.2%), supplemented with starch (0.5%) and yeast extract (0.3%), was retained for production of antibiotics. Active substances were purified by a G25-80 Sephadex column and reverse phase HPLC. Two pure substances were obtained and named ZA01 and ZA02; they were characterized on the basis of combined data resulting from chemical tests, UV visibile and IR spectra and mass spectrometry. The two antibiotics were found to be related and were partially characterized as nucleotidic or nucleosidic antibiotics. Their structures consisted of a chain of three sugar units linked to an aromatic base containing a phosphate residue. PMID:16081249

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

2005-12-01

42

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

43

Vermicompost as a Biological Soil Amendment  

Microsoft Academic Search

\\u000a The viability of using earthworms as a treatment technique for the biological wastes producing organic fertilizers. A variety\\u000a of organic solid wastes, domestic and agro-industrial, can be vermicomposted. Vermicomposting technology involves harnessing\\u000a earthworms as versatile natural bioreactors, which play a vital role in decomposition of organic matter, maintaining soil\\u000a fertility, and bringing out efficient natural recycling and enhanced plants’ growth.

J. Tajbakhsh; E. Mohammadi Goltapeh; Ajit Varma

44

Active Biological Materials  

NASA Astrophysics Data System (ADS)

Cells make use of dynamic internal structures to control shape and create movement. By consuming energy to assemble into highly organized systems of interacting parts, these structures can generate force and resist compression, as well as adaptively change in response to their environment. Recent progress in reconstituting cytoskeletal structures in vitro has provided an opportunity to characterize the mechanics and dynamics of filament networks formed from purified proteins. Results indicate that a complex interplay between length scales and timescales underlies the mechanical responses of these systems and that energy consumption, as manifested in molecular motor activity and cytoskeletal filament growth, can drive transitions between distinct material states. This review discusses the basic characteristics of these active biological materials that set them apart from conventional materials and that create a rich array of unique behaviors.

Fletcher, Daniel A.; Geissler, Phillip L.

2009-05-01

45

Soil solid-phase controls lead activity in soil solution.  

PubMed

Lead pollution of the environment is synonymous with civilization. It has no known biological function, and is naturally present in soil, but its presence in food crops is deemed undesirable. The concern regarding Pb is mostly due to chronic human and animal health effects, rather then phytotoxicity. However, not much is known about the chemistry and speciation of Pb in soils. We determined the activity of Pb2+, in near neutral and alkaline soils, representative of alluvial, desertic and calcareous soils of Egypt, using the competitive chelation method. Lead activity ranged from 10(-6.73) to 10(-4.83) M, and was negatively correlated with soil and soil solution pH (R2 = -0.92, P < 0.01 and R2 = -0.89, P < 0.01, respectively). It could be predicted in soil solution from the equation: log(Pb2+) = 9.9 - 2pH. A solubility diagram for the various Pb minerals found in soil was constructed using published thermodynamic data obtained from the literature, and our measured Pb2+ activities compared with this information. The measured Pb2+ activities were undersaturated with regard to the solubility of PbSiO3 in equilibrium with SiO2 (soil). However, they were supersaturated with regard to the solubilities of the Pb carbonate minerals PbCO3 (cerussite) and Pb3(CO3)2(OH)2 in equilibrium with atmospheric CO2 and hydroxide Pb(OH)2. They were also supersaturated with regard to the solubilities of the Pb phosphate minerals Pb3(PO4)2, Pb5(PO4)3OH, and Pb4O(PO4)2 in equilibrium with tricalcium phosphate and CaCO3. The activity of Pb2+ was not regulated by any mineral of known solubility in our soils, but possibly by a mixture of Pb carbonate and phosphate minerals. PMID:11841061

Badawy, S H; Helal, M I D; Chaudri, A M; Lawlor, K; McGrath, S P

2002-01-01

46

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

47

[Ecological effect of hygroscopic and condensate water on biological soil crusts in Shapotou region of China].  

PubMed

By the method of field experiment combined with laboratory analysis, this paper studied the ecological significance of hygroscopic and condensate water on the biological soil crusts in the vegetation sand-fixing area in Shapotou region of China. In the study area, 90% of hygroscopic and condensate water was within the 3 cm soil depth, which didn' t affect the surface soil water content. The hygroscopic and condensate water generated at night involved in the exchange process of soil surface water and atmosphere water vapor, made up the loss of soil water due to the evaporation during the day, and made the surface soil water not reduced rapidly. The amount of the generated hygroscopic and condensate water had a positive correlation with the chlorophyll content of biological soil crusts, indicating that the hygroscopic and condensate water could improve the growth activity of the biological soil crusts, and thus, benefit the biomass accumulation of the crusts. PMID:23755477

Pan, Yan-Xia; Wang, Xin-Ping; Zhang, Ya-Feng; Hu, Rui

2013-03-01

48

Conceptual Models and Simulations for Biological Clogging in Unsaturated Soils  

Microsoft Academic Search

Biological clogging in unsaturated soils is an important concern in the design of biofilters that are used to treat wastewater in rural areas. Several conceptual models have been developed to simulate biological clogging in saturated flow systems but limited research has been performed to develop similar conceptual models in unsaturated soils. This study developed three conceptual models for biological clogging

M. Mostafa; P. J. Van Geel

2007-01-01

49

[Biological soil crust nitrogenase activity and its responses to hydro-thermic factors in different erosion regions on the Loess Plateau, China].  

PubMed

Based on field survey, the biological soil crusts at their stable development stage were collected from the water erosion region, water-wind erosion region, and wind erosion region on the Loess Plateau, aimed to study the effects of the variations of moisture and temperature on the crusts nitrogenase activity (NA). The NA of the crusts in the erosion regions decreased in the order of water erosion region (127.7 micromol x m(-2) x h(-1)) > water-wind erosion region (34.6 micromol x m(-2) x h(-1)) > wind erosion region (6.0 micromol x m(-2) x h(-1)), and the optimal temperature for the crust nitrogen fixation was 35 degrees C, 25 degrees C, and 15 degrees C, respectively. At the optimal temperature and 100% -40% field water-holding capacity, the NA of the crusts from the water erosion and water-wind erosion regions had no significant difference. The NA of the crusts from the wind erosion region was more sensitive to the variation of moisture, showing a dramatic decline when the moisture decreased to 80% field water-holding capacity, and totally lost when the moisture decreased to 20% field water-holding capacity. The differences in the NA of the crusts from the three erosion regions and the responses of the NA to the variations of moisture and temperature were likely associated with the climate, environment, and the crust species composition. PMID:24175513

Ming, Jiao; Zhao, Yun-Ge; Xu, Ming-Xiang; Yang, Li-Na; Wang, Ai-Guo

2013-07-01

50

Method for Scaling Biological Response of Soil Microcosms.  

National Technical Information Service (NTIS)

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 an...

M. A. Shirazi B. Lighthart J. Gillett

1984-01-01

51

Effects of level and quality of organic matter input on carbon storage and biological activity in soil: Synthesis of a long-term experiment  

NASA Astrophysics Data System (ADS)

The aim of this paper was to synthesize a series of investigations from a long-term field experiment addressing the turnover of organic matter in soil. This paper is based on four organic matter inputs (soil treatments): none (fallow), small amounts of roots+stubble cropped without N fertilizer (no-N), moderate additions of animal manure, and moderate additions of peat. After 42 years, soil carbon stocks declined in the fallow and no-N treated soil but increased in the animal manure and peat-amended soil. Gentle fractionation of soil particles and aggregates revealed that the silt-sized fraction contained most of the soil C and was most responsive to changes in input of organic matter. The clay-sized fraction (<2 ?m) acted as a sink for C, and amounts of clay-sized C increased in all treatments, including fallow. The contribution of size fractions to C storage decreased in the following order: silt > clay > fine sand > coarse sand. The highest natural abundance of 13C and 15N was found in the clay-sized fraction, the fallow being most enriched in 13C and the animal manure-treated soil in 15N, indicating that the organic matter of the clay-sized fraction had been turned over most intensively. The 13C inventory showed that the transfer from silt- to clay-sized carbon was most intensive in the soil treated with animal manure and least intensive in the peat-treated soil. Bacterial diversity increased from sand- to clay-sized fractions revealed by 16S rRNA genes. Fungal activity was highest in coarse-sized fractions as indicated by enzyme measurements. The quality and amount of organic matter input had no significant effect on the community structure of soil bacteria.

Kirchmann, Holger; Haberhauer, Georg; Kandeler, Ellen; Sessitsch, Angela; Gerzabek, Martin H.

2004-12-01

52

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

SciTech Connect

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.

Reeve, Jennifer [Washington State University; Schadt, Christopher Warren [ORNL; Carpenter-Boggs, Lynne [Washington State University; Kang, S. [University of Oklahoma; Zhou, Jizhong [University of Oklahoma, Norman; Reganold, John P. [Washington State University

2010-01-01

53

Impact of Environmental Factors and Biological Soil Crust Types on Soil Respiration in a Desert Ecosystem  

PubMed Central

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.

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

2014-01-01

54

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

55

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

56

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

57

BIOGEOGRAPHY AND BIODIVERSITY OF BIOLOGICAL SOIL CRUSTS ACROSS QUEENSLAND  

Microsoft Academic Search

Recent field research has established that biological soil crust communities (cyanobacteria, lichens, liverworts and mosses) are widespread across the rangelands of Queensland. Our survey has covered many national parks and reserves or private properties where necessary, to take in changes in rainfall gradients, vegetation communities and soils. We document for the first time, well-established and extensive cyanobacteria-dominated soil crusts occurring

Wendy J. Williams; Burkhard Büdel; Colin Driscoll

58

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

59

Fluorescein Diacetate: A Potential Biological Indicator for Arid Soils  

Microsoft Academic Search

A field study was undertaken to identify a potential biological indicator for arid soils. The study area covered five districts (111,681 km) in which annual rainfall varied from 217 to 427 mm and soil texture ranged from sandy to clay loam. The surface 30 cm of arid soil from agricultural field sites differing in soil properties and cropping pattern were used in the

G. K. Aseri; J. C. Tarafdar

2006-01-01

60

Influence of Herbicide-Desiccated Cover Crops on Biological Soil Quality in the Mississippi Delta  

Microsoft Academic Search

The effect of crop residue management (CRM) systems on selected biological properties (microbial biomass\\/populations and soil enzyme activity) of Dundee soils under two cropping systems was investigated. In a cotton (Gossypium hirsutum L.) study, the influence of conventional tillage (CT) and no-tillage (NT) with and without an annual ryegrass cover crop (Lolium multiforum Lam.) on these properties was determined. Annual

S. C. Wagner; R. M. Zablotowicz; M. A. Locke; R. J. Smeda; C. T. Bryson

61

Active Microwave Soil Moisture Research  

Microsoft Academic Search

This paper summarizes the progress achieved in the active microwave remote sensing of soil moisture during the four years of the AgRISTARS program. Within that time period, from about 1980 to 1984, significant progress was made toward understanding 1) the fundamental dielectric properties of moist soils, 2) the influence of surface boundary conditions, and 3) the effects of intervening vegetation

M. CRAIG DOBSON; FAWWAZ T. ULABY

1986-01-01

62

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

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

Biological and biochemical soil indicators: monitoring tools of different agricultural managements  

NASA Astrophysics Data System (ADS)

The intensive agricultural managements, increased in the last twenty years, have resulted in a decrease in fertility of soils, representing a serious threat to agricultural productivity due to both the increase in production cost, mainly for intensive use of mineral fertilizers, and the loss of the quality of crops themselves. Organic matter content is closely related to the soil fertility and its progressive reduction in cultivates soils, without a satisfactory recovery, could make agriculture untenable, resulting in a high detrimental effect on environment. But an appropriate soil management practices can improve soil quality by utilizing organic amendments as alternative to mineral fertilizers to increase soil quality and plant growth. In this context, demand of suitable indicators, whose are able to assess the impact of different agricultural managements on soil quality, has increased. It has shown that soil biological and biochemical properties are able to respond to small changes in soil conditions, thus providing information on subtle alterations in soil quality. Aim of this study was to evaluate the use of soil biological and biochemical properties as fertility indicators in agricultural soils under different agricultural managements, sited in Campania Region (Southern Italy). After a preliminary monitoring phase of soil fertility on different farms sited in five agricultural areas of Campania Region, we have selected two farms in two different study areas to assess the effect on soil quality of different organic amendments. In particular, a compost from municipal solid waste and wood from scraps of poplars pruning were supplied in different doses and ratios. Soil samplings after one month from the amendment addition and then every 4 months until a year were carried out. All collected soil samples were characterized by main physical, chemical, biochemical and biological properties. In general, the use of different organic amendments showed a positive effect on fertility of both soils under intensive farming. In general, all enzymatic activities and organic carbon content increased after 1 month, and they were still higher after 4 months from amendment application. Microbial biomass and soil potential activity (respiration) showed significantly higher values in soils added with organic amendments, for both farms and samplings, with more marked effects on respiration in the first sampling. In conclusion results showed, in general, a quick response as indicators of the assayed biological and biochemical soil properties and a good recovery in fertility of the studied agricultural soils. The project was founded by CCIIAA of Salerno

Scotti, Riccardo; Sultana, Salma; Scelza, Rosalia; Marzaioli, Rossana; D'Ascoli, Rosaria; Rao, Maria A.

2010-05-01

65

Application of MCPA herbicide on soils amended with biostimulants: short-time effects on soil biological properties.  

PubMed

In this paper we studied in the laboratory the effect of MCPA herbicide at a rate of 1.5lha(-1) (manufactures rate recommended) on biological properties of a Plagic Antrosol amended with four biostimulants (WCDS, wheat condensed distillers soluble; PA-HE, hydrolyzed poultry feathers; CGHE, carob germ enzymatic extract; and RB, rice bran extract). Seven hundred grams of soil were mixed with WCDS at a rate of 10%, CGHE at a rate of 4.7%, PA-HE at a rate of 4.3%, and RB at a rate of 4.4%, respectively, in order to applying the same amount of organic matter to the soil (16.38 g organic matter). An unamended polluted and amended non-polluted soil were used as control. For all treatments, the soil ergosterol, dehydrogenase, urease, and phosphatase activities were measured at two incubation times (0 and 60 d). The 16S rDNA-DGGE profiles in all treatments were determined at the beginning and end of the incubation period. The results indicated that at the end of the incubation period and compared with the control soil, the dehydrogenase, urease and phosphatase activities and ergosterol decreased 39.3%, 20%, 15.7% and 56.5%, respectively in the non-organic amended polluted soil. The application of organic matter to unpolluted soil increased the enzymatic activities and ergosterol. However, this stimulation was higher in the soil amended with RB, followed by PA-HE, WCDS and CGHE. The application of herbicide in organic-amended soils decreased the enzymatic activities and ergosterol content. However, this decrease was lower than for the non-amended herbicide polluted soil. Possibly the low molecular weight protein content easily assimilated by soil microorganisms and the adsorption capacity of humic substances are responsible for less inhibition of these enzyme activities and soil ergosterol. The 16S rDNA-DGGE profiles indicated that herbicide did not negatively affect soil bacterial biodiversity. PMID:20510432

Tejada, Manuel; García-Martínez, Ana M; Gómez, Isidoro; Parrado, Juan

2010-08-01

66

Wildfire effects on biological properties of soils in forest-steppe ecosystems of Russia  

NASA Astrophysics Data System (ADS)

Soils affected by forest wildfires in 2010 in Russia were studied on postfire and mature plots near the Togljatty city, Samara region. Soil biological properties and ash composition dynamics were investigated under the forest fire affect: a place of local forest fire, riding forest fire and unaffected site by fire-control (mature) during 3 yr of restoration. Soil samples were collected at 0-15 cm. Soil biological properties was measured by the fumigation method. The analytical data obtained shows that wildfires lead to serious changes in a soil profile and soil chemistry of upper horizons. Wildfires change a chemical composition of soil horizons and increase their ash-content. Fires lead to accumulation of biogenic elements' content (P and K) in the solum fine earth. Calcium content is increased as a result of fires that leads to an alkaline pH of the solum. The values of nutrients decreased as a result of leaching out with an atmospheric precipitation during the second year of restoration. Thus, when the upper horizons are burning the ash arriving on a soil surface enrich it with nutrients. The mature (unaffected by fire) soils is characterized by the greatest values of soil microbial biomass in the top horizon and, respectively, the bigger values of basal respiration whereas declining of the both parameters was revealed on postfire soils. Nevertheless this influence does not extend on depth more than 10 cm. Thus, fire affect on the soil were recognized in decreasing of microbiological activity.

Maksimova, E.; Abakumov, E.

2014-01-01

67

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

Microsoft Academic Search

Biological soil crusts are key mediators of carbon and nitrogen inputs for arid land soils and often represent a dominant portion of the soil surface cover in arid lands. Free-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

Brian J. Darby; Deborah A. Neher; Jayne Belnap

2007-01-01

68

Nitrogen fixation in biological soil crusts from southeast Utah, USA  

USGS Publications Warehouse

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 Nostoc commune and Scytonema myochrous (dark crusts); and (3) the soil lichen Collema sp. At all observation times, Collema had higher nitrogenase activity (NA) than dark crusts, which had higher NA than light crusts, indicating that species composition is critical when estimating N inputs. In addition, all three types of crusts generally responded in a similar fashion to climate conditions. Without precipitation within a week of collection, no NA was recorded, regardless of other conditions being favorable. Low (26??C) temperatures precluded NA, even if soils were moist. If rain or snow melt had occurred 3 or less days before collection, NA levels were highly correlated with daily average temperatures of the previous 3 days (r2=0.93 for Collema crusts; r2=0.86 for dark crusts and r2=0.83 for light crusts) for temperatures between 1??C and 26??C. If a precipitation event followed a long dry period, NA levels were lower than if collection followed a time when soils were wet for extended periods (e.g., winter). Using a combination of data from a recording weather datalogger, time-domain reflectometry, manual dry-down curves, and N fixation rates at different temperatures, annual N input from the different crust types was estimated. Annual N input from dark crusts found at relatively undisturbed sites was estimated at 9 kg ha-1 year-1. With 20% cover of the N-fixing soil lichen Collema, inputs are estimated at 13 kg ha-1 year-1. N input from light crusts, generally indicating soil surface disturbance, was estimated at 1.4 kg ha-1 year-1. The rates in light crusts are expected to be highly variable, as disturbance history will determine cyanobacterial biomass and therefore N fixation rates.

Belnap, J.

2002-01-01

69

Contribution of microbial activity to virus reduction in saturated soil  

Microsoft Academic Search

Application of wastewater to soil may result in the contamination of groundwater and soil with pathogenic microorganisms and other biological and chemical agents. This study was performed to determine the antiviral microbial activity of soil saturated with secondary effluent. Low concentrations (0.05mg\\/ml) of protease pronase resulted in the inactivation of more than 90% of seeded Cox-A9 virus, whereas Poliovirus type

A. M. Nasser; R. Glozman; Y. Nitzan

2002-01-01

70

Atmospheric ice nucleation by fertile soil dusts particles: Relative importance of mineral and biological components  

NASA Astrophysics Data System (ADS)

Dusts emitted from agricultural soils may represent a significant source of atmospheric particulates at mid-latitudes. Such dusts, which can be aerosolised by anthropogenic agricultural activities, have previously been estimated to be present in the atmosphere at sufficient number densities that they could potentially compete with other known ice nuclei (IN). In contrast to soils from arid regions, such as the Sahara, fertile soils contain a larger fraction of biological material, which can lead to an enhancement in the ice nucleating ability of their associated dusts. However, considerable uncertainties remain regarding the relative efficacy of soil dust particles from fertile soils as IN. Using an experimental methodology designed to increase sensitivity to a wide range of ice nucleation efficiencies, we have characterized the immersion mode ice nucleating activities of sub 11 ?m particles extracted from surface soils collected in four locations around England. By using a variety of droplet sizes, from pico-to micro-litre, we have been able to characterize the ice active site densities in soils (estimated using a time-independent framework) at temperatures ranging from -5°C down to the homogeneous limit of freezing at ~ -36°C. At temperatures below -15°C, we find that the ice active site densities tend towards those expected from the mineral components in the soils, suggesting that the inorganic fraction of soil dusts becomes increasingly important in the initiation of the ice phase at large supercoolings. Conversely, above -15°C we find that the ice nucleating activity of the soils dusts was larger than expected from the mineral composition of the soils. The sites responsible for this high temperature ice nucleating activity were sensitive to heat treatment and digestion with hydrogen peroxide, suggesting that they are biological in origin. We conclude that although only being a relatively minor contributor to the global atmospheric dust burden, the enhanced IN activities of dusts generated from agricultural activities may impact upon cloud glaciation, particularly at temperatures above -15°C.

O'Sullivan, Daniel; Murray, B. J.; Malkin, T. L.; Webb, M. E.; Whale, T. F.; Atkinson, J. D.; Baustian, K. J.

2013-05-01

71

Solar Energy Project, Activities: Biology.  

ERIC Educational Resources Information Center

This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of biology experiments. Each unit presents an introduction; objectives; skills and knowledge needed; materials; methods; questions; recommendations for further work; and a teacher information sheet. The teacher information…

Tullock, Bruce, Ed.; And Others

72

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

73

Bioaugmentation, Biostimulation, and Biocontrol in Soil Biology  

Microsoft Academic Search

\\u000a Soils sustain an immense diversity of prokaryotic and eukaryotic organisms. Microbial functions in ecosystems are as diverse\\u000a as the microbes themselves. Differences in microbial community structures reflect the abilities of microorganisms to respond\\u000a to specific environmental factors and substrates. Microbes adapt to these microhabitats and live together in consortia, interacting\\u000a with each other and with other parts of the soil

Ajay Singh; Nagina Parmar; Ramesh C. Kuhad; Owen P. Ward

74

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

75

Measurement of 14CO2 Assimilation in Soils: an Experiment for the Biological Exploration of Mars  

PubMed Central

A method is described for the measurement of 14CO2 assimilation by microorganisms in soils. A determination involves exposing soil to 14CO2, pyrolyzing the exposed soil, trapping the organic pyrolysis products on a column of firebrick coated with CuO, combusting the trapped organics by heating, and measuring the radioactivity in the CO2 produced in the combustion. The detection of significant levels of 14C in the trapped organic fraction appears to be an unambiguous indication of biological activity. The 14CO2 which is adsorbed or exchanged into soils by nonbiological processes does not interfere. The method easily detects the 14CO2 fixed by 102 to 103 algae after light exposure for 3 to 24 hr. Assimilation of 14C is also demonstrable in dark-exposed soils containing 105 to 106 heterotrophic bacteria. Possible applications of the method in the biological exploration of Mars are discussed. Images

Hubbard, Jerry S.; Hobby, George L.; Horowitz, Norman H.; Geiger, Paul J.; Morelli, Frank A.

1970-01-01

76

Humic acid toxicity in biologically treated soil contaminated with polycyclic aromatic hydrocarbons and pentachlorophenol.  

PubMed

Contaminated soil from a land treatment unit at the Libby Groundwater Superfund Site in Libby, MT, was amended with 14C pyrene and incubated for 396 days to promote biodegradation and the formation of soil-associated bound residues. Humic and fulvic acids were extracted from the treated soil microcosms and analyzed for the presence of pyrene residues. Biologic activity promoted 14C association with the fulvic acid fraction, but humic acid-associated 14C did not increase with biologic activity. The Aboatox flash toxicity assay was used to assess the toxicity of humic and fulvic acid fractions. The fulvic acid gave no toxic response, but the humic acid showed significant toxicity. The observed toxicity was likely associated with pentachlorophenol, a known contaminant of the soil that was removed by solvent extraction of the humic acid and that correlated well with toxicity reduction. PMID:16170453

Nieman, J K C; Sims, R C; Sorensen, D L; McLean, J E

2005-10-01

77

Response of Soil Microbiological Activities to Cadmium, Lead, and Zinc Salt Amendments  

Microsoft Academic Search

cal processes important for sustaining soil fertility and quality in the ecosystem. Heavy metal pollution of soil has been recognized as a major factor There is a substantial amount of published data as- impeding soil microbial processes. From this perspective, we studied responses of the soil biological activities to metal stress simulated by sessing the behavior of microorganisms under metal

T. I. Stuczynski; G. W. McCarty; G. Siebielec

2003-01-01

78

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

79

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

80

Biological soil disinfestation : a safe and effective approach for controlling soilborne pests and diseases  

Microsoft Academic Search

Biological soil disinfestation (bsd) is an environmentally friendly method to disinfest the soil from soilborne fungi and nematodes. With biological soil disinfestation a green manure crop (40 tonnes per ha) or other green biomass is homogeneously incorporated into the soil layer that has to be disinfested. Then the field is lightly compacted and irrigated. Subsequently, the soil is covered with

J. G. Lamers; P. J. Wanten; W. J. Blok

2004-01-01

81

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

82

[Relationships between soil nutrients and rhizospheric soil microbial communities and enzyme activities in a maize-capsicum intercropping system].  

PubMed

By using plastic sheet and nylon mesh to partition the root systems of maize and capsicum in a maize-capsicum intercropping system, this paper studied the relationships between soil biological factors and nutritive status in the intercropping system, with no partitioning and maize monoculture and capsicum monoculture as the control. The results showed that intercropping maize and capsicum had its high superiority. In the treatments of no partitioning and nylon mesh portioning in the intercropping system, soil enzyme activities, microbial individuals and nutrient contents were significantly higher, compared with those in the treatments of nylon mesh partitioning and monocultures. All kinds of soil available nutrients showed significant or very significant positive correlations with soil biological factors, except that soil available Mg was negatively correlated with soil fungi and catalase activity. Pathway analysis indicated that in the intercropping system, soil urease, catalase, protease, and bacteria were the main factors affecting the accumulation of soil organic matter, saccharase was the most important factor affecting soil alkali-hydrolyzable N, urease was the most important factor affecting soil available P, and bacteria largely determined soil available K. Soil alkaline phosphatase and fungi selectively affected the accumulation of soil organic matter and available N, P and K. There was a slight negative correlation between soil actinomycetes and soil nutrients, suggesting that actinomycetes had little effect on soil nutrient formation. PMID:18333449

Xu, Qiang; Cheng, Zhi-Hui; Meng, Huan-Wen; Zhang, Yu

2007-12-01

83

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

84

Assessing soil biological characteristics: a comparison of bulk soil community DNA, PLFA-, and Biolog™analyses  

Microsoft Academic Search

Soil microbiological analyses may serve as a means for assessing soil characteristics. Standard microbiological culture-techniques, however, leave over 90% of the microorganisms in the environment unaccounted for. Several more recently developed analytical techniques such as DNA, phospholipid fatty acid (PLFA), and community level substrate utilization (CLSU) fingerprints allow for more detailed analyses of soil microbial communities. We applied analyses of

F. Widmer; A. Fließbach; E. Laczkó; J. Schulze-Aurich; J. Zeyer

2001-01-01

85

Characterization of Soil Samples of Enzyme Activity  

ERIC Educational Resources Information Center

Described are nine enzyme essays for distinguishing soil samples. Colorimetric methods are used to compare enzyme levels in soils from different sites. Each soil tested had its own spectrum of activity. Attention is drawn to applications of this technique in forensic science and in studies of soil fertility. (Author/AJ)

Freeland, P. W.

1977-01-01

86

Influence of some physicochemical and biological parameters on soil structure formation in alluvial soils  

Microsoft Academic Search

This study examines the role of abiotic (texture, calcium carbonates or iron) and biotic parameters (earthworm and enchytraeid activities) on the initial phases of soil aggregation. Our research focused on humus forms in alluvial soils, which are considered as young and heterogeneous environments. We hypothesized that the soil structure formation is determined by both the nature of the recent alluvial

Géraldine Bullinger-Weber; Renée-Claire Le Bayon; Claire Guenat; Jean-Michel Gobat

2007-01-01

87

Molecular characteristics versus biological activity  

USGS Publications Warehouse

The molecular characteristics of mononitrophenols containing halogens not only play a key role in their biological activity but provide a novel example of selective toxicity among vertebrate animals. It has been reported that efforts to control the parasitic sea lamprey in the Great Lakes are directed at present to the applications of a selective toxicant to streams inhabited by lamprey larvae. Since 1961, the larvicide that has been used almost exclusively in the control program has been 3-trifluoromethyl-4-nitrophenol (TFM). However, this is only one of about 15 closely related compounds, all halogen-containing mononitrophenols, that display a selectively toxic action upon lampreys. Although not all of the halogenated mononitrophenols are selectively toxic to lampreys (in fact, fewer than half of those tested), no other group of related compounds has displayed any useful larvicidal activity except for the substituted nitrosalicylanilides.

Applegate, Vernon C.; Smith, Manning A.; Willeford, Bennett R.

1967-01-01

88

Biological Soil Crusts: Webs of Life in the Desert  

USGS Publications Warehouse

Although the soil surface may look like dirt to you, it is full of living organisms that are a vital part of desert ecosystems. This veneer of life is called a biological soil crust. These crusts are found throughout the world, from hot deserts to polar regions. Crusts generally cover all soil spaces not occupied by green plants. In many areas, they comprise over 70% of the living ground cover and are key in reducing erosion, increasing water retention, and increasing soil fertility. In most dry regions, these crusts are dominated by cyanobacteria (previously called blue-green algae), which are one of the oldest known life forms. Communities of soil crusts also include lichens, mosses, microfungi, bacteria, and green algae. These living organisms and their by-products create a continuous crust on the soil surface. The general color, surface appearance, and amount of coverage of these crusts vary depending on climate and disturbance patterns. Immature crusts are generally flat and the color of the soil, which makes them difficult to distinguish from bare ground. Mature crusts, in contrast, are usually bumpy and dark-colored due to the presence of lichens, mosses, and high densities of cyanobacteria and other organisms.

Belnap, Jayne

2001-01-01

89

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

90

Carbondioxide exchange of biological soil crusts compared to disturbed soil / sand in semi arid areas  

NASA Astrophysics Data System (ADS)

Sparse vegetation in semi arid and arid lands is associated with low productivity and minor contribution to biosphere-atmosphere exchange of greenhouse gases, on an area basis. Dryland ecosystems, however, cover large land areas that are continuously increasing. Two third of global population live in semi arid and arid regions and its direct impact contributes to the expansion of dryland ecosystems. Satellite images at the start of the wet season in natural dryland ecosystems clearly show significant photosynthetic activity at a time when most vascular plants are yet inactive or undeveloped, indicating a possibly neglected CO_2 sink. This can likely be assigned to the so-called biological soil crusts (BSC) that consist of poikilohydric microphytes such as cyanobacteria, lichens, green algae, and mosses, which can rapidly recover photosynthesis in response to the earliest water supply. Such non-vascular vegetation activities are an important feature of dryland ecosystems worldwide, often complementary to that of vascular plants. We report on the rates of CO_2 exchange of BSC as measured at two field sites in the northern Negev desert during six months during 2001/2002. Peak rates of net photosynthesis (1.5 - 2 ?mol m-2 s-1) were in the range observed in vascular plants, but periods with low or no activities were considerable. Rates of CO_2 exchange of BSC was always compared with that of bare soil / sand. This allowed both estimating net local land surface exchange, and assessing the influence of disturbance, mainly by uncontrolled land use, of the highly vulnerable BSC ecosystems. Simultaneous measurements of spectral reflectance properties of BSC in this study aim to allow calibration of airborne remote sensing for large-scale BSC activity studies.

Wilske, B.; Yakir, D.; Burgheimer, J.; Karnieli, A.; Zaady, E.; Kesselmeier, J.

2003-04-01

91

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

92

[Effects of biological soil crust at different succession stages in hilly region of Loess Plateau on soil CO2 flux].  

PubMed

Biological soil crust (biocrust) is a compact complex layer of soil, which has photosynthetic activity and is one of the factors affecting the CO2flux of soil-atmosphere interface. In this paper, the soil CO, flux under the effects of biocrust at different succession stages on the re-vegetated grassland in the hilly region of Loess Plateau was measured by a modified LI-8100 automated CO, flux system. Under light condition, the soil CO2 flux under effects of cyanobacteria crust and moss crust was significantly decreased by 92% and 305%, respectively, as compared with the flux without the effects of the biocrusts. The decrement of the soil CO, flux by the biocrusts was related to the biocrusts components and their biomass. Under the effects of dark colored cyanobacteria crust and moss crust, the soil CO2 flux was decreased by 141% and 484%, respectively, as compared with that in bare land. The diurnal curve of soil CO2 flux under effects of biocrusts presented a trend of 'drop-rise-drop' , with the maximum carbon uptake under effects of cyanobacteria crust and moss crust being 0.13 and -1.02 micromol CO2.m-2.s-1 and occurred at about 8:00 and 9:00 am, respectively, while that in bare land was unimodal. In a day (24 h) , the total CO2 flux under effects of cyanobacteria crust was increased by 7.7% , while that under effects of moss crust was decreased by 29.6%, as compared with the total CO2 flux in bare land. This study suggested that in the hilly region of Loess Plateau, biocrust had significant effects on soil CO2 flux, which should be taken into consideration when assessing the carbon budget of the 'Grain for Green' eco-project. PMID:23755478

Wang, Ai-Guo; Zhao, Yun-Ge; Xu, Ming-Xiang; Yang, Li-Na; Ming, Jiao

2013-03-01

93

The effect of biochar in soil enzyme activities: Latest advances and future directions  

NASA Astrophysics Data System (ADS)

In the last years there has been an increasing interest in biochar research. Soil biological and biochemical properties have a preeminent role driving nutrient cycling and can be considered as indicators of soil quality. The information on the effects of biochar addition in soil biological activities in still scarce, although an influential number of articles have appeared lately. The aim of this work is to provide an overview of those articles dealing with the biological impact of biochar addition to soil. Studies conducted in soils in different countries differing in forming factors and fertility status are presented. The focus of this work is on how biochar interacts with soil fauna, on changes in soil biological and biochemical properties following heavy metal immobilization after biochar addition and on how these changes are important in relation to global change. Priority areas were research is needed are identified.

Paz-Ferreiro, Jorge; Méndez, Ana; Gascó, Gabriel

2014-05-01

94

Photoregulation of biologically active macromolecules.  

PubMed

A broad view is given of photoregulated processes as they occur in algae, fungi, halophilic bacteria, higher plants, invertebrates, and higher animals. Emphasis is on the following: the organs, tissues, and organelles that participate; the nature of the photoreceptor pigments; the light-induced structural changes that occur in the photopigments; and the way in which the photochemical events are believed to be translated into the physiological response. An attempt is made to show that there exist common biochemical attributes in all systems. In particular, they depend upon the ability of a low-molecular-weight to regulate a biologically active macromolecule, which may or may not be incorporated into a membrane. This is a common type of biochemical regulation and is, for example, the basis of allosterism. The additional refinement in photosensitive systems is the ability of light to alter the stereochemistry of the low-molecular-weight effector molecule and thus to modify its effect on the macromolecule. Model photosensitive systems are examined that incorporate control mechanisms that function in natural systems. For example, there are systems in which enzymes, normally insensitive to light, are made subject to photoregulation. In others, membrane permeability is rendered photoresponsive. A comparison of the model systems was processes found in nature permits the formulation of an hypothesis to explain how naturally occurring photoresponsive systems might have evolved. PMID:822780

Erlanger, B F

1976-01-01

95

Concepts for Biologically Active Peptides  

PubMed Central

Here we review a unique aspect of CNS research on biologically active peptides that started against a background of prevalent dogmas but ended by exerting considerable influence on the field. During the course of refuting some doctrines, we introduced several concepts that were unconventional and paradigm-shifting at the time. We showed that (1) hypothalamic peptides can act ‘up’ on the brain as well as ‘down’ on the pituitary, (2) peripheral peptides can affect the brain, (3) peptides can cross the blood-brain barrier, (4) the actions of peptides can persist longer than their half-lives in blood, (5) perinatal administration of peptides can exert actions persisting into adulthood, (6) a single peptide can have more than one action, (7) dose-response relationships of peptides need not be linear, (8) the brain produces antiopiate as well as opiate peptides, (9) there is a selective high affinity endogenous peptide ligand for the mu-opiate receptor, (10) a peptide’s name does not restrict its effects, and (11) astrocytes assume an active role in response to metabolic disturbance and hyperleptinemia. The evolving questions in our laboratories reflect the diligent effort of the neuropeptide community to identify the roles of peptides in the CNS. The next decade is expected to see greater progress in the following areas: (a) interactions of peptides with other molecules in the CNS; (b) peptide involvement in cell-cell interactions; and (c) peptides in neuropsychiatric, autoimmune, and neurodegenerative diseases. The development of peptidomics and gene silencing approaches will expedite the formation of many new concepts in a new era.

Kastin, Abba J.; Pan, Weihong

2012-01-01

96

Variations of soil enzyme activities in a temperate forest soil  

Microsoft Academic Search

Soil enzyme activities (dehydrogenase, urease, phosphatase, and arylsulfatase) in a temperate forest soil were determined\\u000a in relation to landscape position and seasons. Overstory of the area is dominated by Quercus mongolica, Kalopanax pictus, Carpicus cordata, and Acer pseudo-sieboldianum. The activities were measured in three patches, namely a north-facing backslope, a ridge, and a south-facing backslope in\\u000a autumn and spring over

Hojeong Kang; Sinkyu Kang; Dowon Lee

2009-01-01

97

Evolution of soil biological properties after addition of glyphosate, diflufenican and glyphosate+diflufenican herbicides.  

PubMed

The aim of this paper was to study in laboratory the degradation and the effects on biological properties in two soils after the addition of glyphosate, diflufenican and glyphosate+diflufenican. One hundred grams of sieved soil (<2mm) were mixed with (i) 13mL of Zarpa (16% glyphosate and 4% diflufenican) prepared in a water solution of 1L (0.52g of glyphosate and 2.08g of diflufenican), (ii) 5.2mL of Round up (40% glyphosate), prepared in a water solution of 1L (0.52g of glyphosate), and (iii) 1.19mL of Brodal (43.5% diflufenican), prepared in a water solution of 1L (2.08g of diflufenican). Soil samples were collected after 0, 1, 5, 10, 15, 30, 60, 120 and 180d of incubation and analyzed for microbial biomass-C and dehydrogenase, urease, beta-glucosidase, phosphatase, arylsulphatase activities and glyphosate and diflufenican contents. At the end of the experiment, in the clayey texture soil the glyphosate and diflufenican contents were higher 50% and 30.7%, respectively, for the glyphosate+diflufenican treatment compared to glyphosate and diflufenican treatments, respectively. In the sandy loam texture soil the glyphosate and diflufenican contents were higher (38.9% and 39.4%, respectively) when the glyphosate and diflufenican were added as Zarpa than Round up or Brodal. The application of glyphosate+diflufenican mixture to soil increased the toxic effects of both herbicides in the soil biological activity and the individual soil persistence of each herbicide. PMID:19376558

Tejada, Manuel

2009-07-01

98

Improvement of activated sludge dewaterability by humus soil induced bioflocculation.  

PubMed

Effects of humus soil particles on the dewaterability of activated sludge were investigated. Cations leaching increased proportionally with the dosage of humus soil, and the leaching was not significant after 2 h. Divalent cations, Ca2+ and Mg2+, leaching from the humus soil played an important role in improving dewaterability of the biological sludge. On the contrary, dewaterability was not affected or slightly deteriorated by the monovalent cations, K+ and Na+ leached from the humus soil. Improvement in dewaterability of the sludge by addition of humus soil was higher than that of equivalent cations mixture. It seemed that the decrease of supracolloidal bio-particles (1 to 100 microm in diameter) resulted in diminishing of the blinding effect on cake and filter medium. SRF (specific resistance to filtration) of the humus soil added sludge varied in parallel with the M/D (monovalent to divalent cation) ratio, and the M/D ratio could be utilized as a useful tool for evaluation of the sludge dewatering characteristics. Long-term effects of humus soil on the improvement of activated sludge dewaterability were clearly identified by continuous operation results of a bench-scale MLE (Modified Ludzack Ettinger) system combined with a humus soil contactor. On the other hand, dewaterability of the control sludge was only slightly improved by a decrease in M/D ratio of the wastewater influent. PMID:15242121

Choi, Young-Gyun; Kim, Seong-Hong; Kim, Hee-Jun; Kim, Gyu Dong; Chung, Tai-Hak

2004-01-01

99

The biological factors influence on the conversion of mineral components of Extremely Arid Desert Soils (Kazakhstan)  

NASA Astrophysics Data System (ADS)

Extremely arid soils of stony deserts (hamadas) along the southern periphery of the Ili Depression are considered to be analogous to extremely arid soils of Mongolia, also named as "ultra-arid primitive gray-brown soils." In general, the morphology of extremely arid soils of hamadas in the Ili Depression is similar to that of the soils of stony deserts in other parts of the world, including the Gobi, Atacama, and Tarim deserts. The diagnostics of the active communities of microorganisms were performed according to the method of Rybalkina-Kononenko. The exact identification of the living forms of microorganisms to the species level is not always possible with the use of this method. However, it allows us to study the physiological role of the microorganisms and their ecological functions, including the relationships with the soil matrix and other organisms. In particular, it is possible to estimate the contribution of the microorganisms to the transformation of mineral soil components. The obtained materials allow us to conclude that the extremely arid desert soils are characterized by the very high biological activity during short periods of the increased soil moistening after rare and strong rains. The diversity of living forms is very considerable; both prokaryotes (cyanobacteria, actinomycetes, and iron bacteria) and protists (green algae, diatoms, and dinoflagellates) are developed in the soil. Thus, during a short period after the rains, these microorganisms pass from the stage of anabiosis to the stage of active growth and reproduction. Then, upon drying of the soil, the biotic activity of the soil slows down and, finally, terminates. The organisms remain in the state of anabiosis until the next rain. During the period of active growth, the microorganisms compose a specific consortium of different species and exert a profound impact on the soil properties. They participate in the transformation of the soil minerals with the formation of amorphous substances that are clearly seen in biofilms on the surface of gravels of the desert pavement and on the walls of vesicular pores in the crust and subcrust (AKL) horizons of the soil. The organomineral compounds are accumulated in the vesicular pores due to the synthesis and mineralization of the microbial biomass. This is a specific feature of the humus-accumulative process in the extremely arid desert soils. The biogenic transformation of iron-containing minerals, the mobility of iron, and its accumulation in films and coagulated microforms is largely due to the living activity of iron bacteria. These iron pedofeatures are specific of the extremely arid desert soils. We suppose that some part of vesicular pores in the AKL horizon has a microbiological origin, because separate bacterial cells may form intracellular gas vacuoles and extracellular gas bulbs, as well as membrane sacs and cell dilatations that can shape the vesicular pores. In general, our data indicate that soils, including extremely arid desert soils, serve as reservoirs of the microbial diversity and ensure the development and preservation of diverse microorganisms with specific mechanisms of adaptation to the sharp changes in the environmental conditions. This biota-protecting role of soils is particularly well pronounced during the climatic pessimum. This study was supported by the Russian Foundation for Basic Research, project no. 12-04-00990a.

Kutovaya, Olga; Vasilenko, Elena; Lebedeva, Marina; Tkhakakhova, Azida

2013-04-01

100

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

101

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 Guimarães, Amanda; Duque Jaramillo, Paula Marcela; Rufini, Márcia; Marra, Leandro Marciano; Varón López, Maryeimy; Pereira da Silva, Michele Aparecida; Fonsêca Sousa Soares, Cláudio Roberto; de Souza Moreira, Fatima Maria

2013-12-01

102

Organic matter components, aggregate stability and biological activity in a horticultural soil fertilized with different rates of two sewage sludges during ten years  

Microsoft Academic Search

The effects of the application as fertilizer during ten years of two sewage sludges (aerobically and anaerobically digested, at rates of 400, 800, and 1200 kg of N\\/ha yr), on the aggregate stability and contents of related organic matter components, microbial biomass and levels of five enzymatic activities (alkaline phosphomonoesterase, phosphodiesterase, urease, arylsulphatase and dehydrogenase) were investigated. The application of

R Albiach; R Canet; F Pomares; F Ingelmo

2001-01-01

103

Biological Soil Disinfestation (BSD) of Soilborne Pathogens and Its Possible Mechanisms  

Microsoft Academic Search

Biological soil disinfestation (BSD) is one of the methods for soil disinfestation recently developed and consists of organic amendment, irrigation, and covering the soil surface with plastic film. BSD trials with artificially infested soils effectively killed Fusarium oxysporum f. sp. lycopersici and Ralstonia solanacearum. F. oxysporum f. sp. lycopersici was not detected 9 days after treatment. Application of BSD to

Noriaki MOMMA

2008-01-01

104

Changes in the biological diversity and concentration of total DNA under the influence of mineral fertilizers in agrochernozemic soils  

NASA Astrophysics Data System (ADS)

Chernozems represent the most valuable soil resource for Russian agriculture. Their sustainable use in intensive farming systems with preservation of the biological diversity and biological activity of these soils is of crucial importance for the agri-environmental security of Russia. We studied the influence of different rates of mineral fertilizers on the biological activity of chernozems on experimental fields of the Dokuchaev Research Institute of Agriculture in Kamennaya Steppe (Voronezh oblast). Soil samples were taken at the end of April 2013 from the plow horizon on trials with different rates of fertilization: NPK-0, NPK-60, and NPK-120 (kg/ha); a long-term fallow plot was used as an absolute control. The biological activity was analyzed by routine inoculation methods and by the molecular biology techniques based on DNA isolation from the soil samples. Quantitative parameters of the isolated and purified DNA were determined by measuring the fluorescence of the DNA preparations with added intercalating dyes; GelDoc XR system and Image Lab and TotalLab Quant. software were used. Microbiological studies showed the high biological activity of the chernozems soil in all the trials. No significant differences were found between the trials for the microbiological processes of the carbon cycle. There was a weakly expressed tendency for an increase in the activity of actinomycetes from the soil with zero fertilization (5.11 log10CFU/g) to the soil with maximum (NPK-120) fertilization (5.69 log10CFU/g) and the fallow soil (5.73 log10CFU/g); the number of cultivated micromycetes decreased from the soil with zero fertilization (4.76 log10CFU/g) to the soil with maximum fertilization (4.14 log10CFU/g) and to the fallow soil (4.1 log10CFU/g). A less equilibrium state is typical of the microorganisms participating in the nitrogen cycle. The number of cultivated aerobic and anaerobic nitrogen-fixing bacteria somewhat increased in the fertilized trials (NPK-60, NPK-120). The most active development of denitrifiers was in the fallow soil. It is known that cultivated forms comprise only about 1 to 10% of the total number of soil microorganisms. Quantitative analysis by the methods of molecular biology makes it possible to consider the full range of microorganisms. The concentration of extracted DNA can serve as an indicator of the total "biogenity" of the soil, as we isolated the genetic material of all organisms living in the soil. The highest concentration of DNA found in the samples from the fallow soil. Much lower values were found in the soils treated with mineral fertilizers: 38.9% in trial NPK-60 and 53.3% in trials NPK-120 and NPK-0. Thus, to sustain biota in cultivated chernozems and to improve the ecological state of the fields, the rates of mineral fertilizers have to be properly controlled. Moderate rates can be recommended. Features of the soil microbiome can serve as universal and sensitive indicators of the state of the soils under different farming systems. The quantitative analysis of isolated total DNA is an efficient tool to control the ecological state of the soils, especially those involved in agriculture.

Tkhakakhova, Azida; Kutovaya, Olga; Ivanova, Ekaterina; Pavlyuchenko, Anatoly

2014-05-01

105

Contribution of microbial activity to virus reduction in saturated soil.  

PubMed

Application of wastewater to soil may result in the contamination of groundwater and soil with pathogenic microorganisms and other biological and chemical agents. This study was performed to determine the antiviral microbial activity of soil saturated with secondary effluent. Low concentrations (0.05mg/ml) of protease pronase resulted in the inactivation of more than 90% of seeded Cox-A9 virus, whereas Poliovirus type 1, Hepatitis A virus (HAV) and MS2 bacteriophages were found to be insensitive to the enzyme activity. Exposure of Cox A9 virus to P. aeruginosa extracellular enzymes resulted in 99% inactivation of the seeded virus. Hepatitis A virus was found to be as sensitive as the Cox A9 virus, whereas Poliovirus 1 and MS2 were found to be insensitive to P. aeruginosa extracellular enzymatic activity. Furthermore, the time required for 99% reduction (T99) of Cox A9 and MS-2 Bacteriophage, at 15 degrees C, in soil saturated with secondary effluent was found to be 7 and 21 days, respectively. Faster inactivation was observed for MS2 and Cox A9 in soil saturated with secondary effluent incubated at 30 degrees C, T99 of 2 and 0.3 days, respectively. Although the concentration of the total bacterial count in the soil samples increased from 10(3) cfu/g to 10(5) cfu/g after 20 days of incubation at 30 degrees C, the proteolytic activity was below the detection level. The results of this study indicate that the virucidal effect of microbial activity is virus type dependent. Furthermore microbial activity in the soil material can be enhanced by the application of secondary effluent at higher temperature. The results also showed that MS2 bacteriophage can be used to predict viral contamination of soil and groundwater. PMID:12153026

Nasser, A M; Glozman, R; Nitzan, Y

2002-05-01

106

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

107

Soil tillage induced impacts on soil microbial activity of agriculturally used soils in Austria  

NASA Astrophysics Data System (ADS)

Soil can act as a net sink for sequestering carbon and thus attenuating the increase in atmospheric CO2 if appropriate soil and crop management is applied. The objectives of this study are to determine the impacts of different tillage treatments on soil microbial activity. Soil microbial respiration (MR), substrate-induced respiration (SIR), ß-glucosidase activity (GLU) and dehydrogenase (DHY) activity were analysed for five agricultural fields in Lower Austria and Styria in 2007 and 2008. These investigations are part of a research project about the influence of soil tillage on CO2 emissions and carbon dynamics of Austrian cropland. The study sites differ in climatic conditions, soil texture, slope and crop rotation. All fields belong to long-term tillage treatment experiments performed by agricultural schools. Three different tillage systems are investigated: Conventional tillage (CT), Reduced tillage (RT) and No-tillage (NT). RT and NT use cover crops during the winter period. Each tillage system is replicated three times per site. In spring, summer and autumn 2007 and 2008, soil samples were taken from each plot at the soil depth of 0-10 cm, 10-20 cm and 20-30 cm. Samples were sieved (2 mm) and stored at 4°C in a refrigerator. Analyses were performed within one month after sampling. In addition, soil moisture, pH value and carbon and nitrogen content of the soil samples were determined. Preliminary results show that the amount of microbiological activity differs between the five sites during experimental years depicting the influence of soil texture. The influence of tillage treatment on soil microbial parameter was best represented by SIR. For all fields, values changed during the vegetation period. The impact of soil texture and soil depth could be analysed by all investigated soil microbial parameters whereas the tillage treatment showed a significant influence only for SIR.

Baatar, Undrakh-Od; Klik, Andreas; Trümper, Gerlinde

2010-05-01

108

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 activities are described in student handouts and teacher notes; the student handouts are available as Word files for teachers to customize for their students. The hands-on experiments and simulation activities are available at http://serendip.brynmawr.edu/sci_edu/waldron/. To accommodate limited budgets, most of the hands-on activities can be carried out with minimum equipment and expense for supplies.

Waldron, Ingrid; Doherty, Jennifer

109

Including physical and biological soil crusts properties in gully prediction  

NASA Astrophysics Data System (ADS)

In Sahelian region, concentrated overland flow often leads to the formation of gullies. Although this phenomenon is widespread in those regions, research efforts are still needed to be able to model their spatial distribution and the role of the different parameters involved in this process. In this context, the objectives of this study are twofold. The first step is to investigate to what extent the role of Sahelian soil surface crusts (biological and/or physical) on soil surface infiltrability and detachment affect the formation and development of gullies. The second step is to integrate the results of these investigations in a simple geomorphological model to predict gully location at the watershed scale. The evaluation of the resulting model on two test catchments demonstrated that the integration of soil crusting is a key parameter to insure the quality and relevance of gully prediction. The model is able to distinguish between two types of gullies, those whose width range between 0.5m and 4m and those whose width exceeds 4m. The application of the model at the regional scale is however limited by the resolution of available regional digital elevation model (i.e. the 90m resolution SRTM DEM) which only permits the prediction of large gullies (width > 4m).

Gay, A.; Cerdan, O.; Desprats, J. F.; Malam Issa, O.; Valentin, C.; Rajot, J. L.; Descroix, L.

2012-04-01

110

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 cm² 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

111

In-situ LIF Analysis of Biological and Petroleum-based Hydraulic Oils on Soil  

PubMed Central

Absorption and fluorescence properties of 4 hydraulic oils (3 biological and 1 petroleum-based) were investigated. In-situ LIF (laser-induced fluorescence) analysis of the oils on a brown sandy loam soil was performed. With calibration, quantitative detection was achieved. Estimated limits of detection were below ca. 500 mg/kg for the petroleum-based oil and ca. 2000 mg/kg for one biological oil. A semi-quantitative classification scheme is proposed for monitoring of the biological oils. This approach was applied to investigate the migration of a biological oil in soil-containing compartments, namely a soil column and a soil bed.

Lemke, Matthias; Fernandez-Trujillo, Rebeca; Lohmannsroben, Hans-Gerd

2005-01-01

112

Microbial Activity of Soil Following Steam Treatment  

Microsoft Academic Search

The effect of steam treatment on subsurface aerobic and anaerobic microbial communities was investigated using multiple microbial assays. Soil samples were gathered and analyzed prior to, one month after, and eight months after a five-month field pilot test of steam injection and extraction. Aerobic soil samples were analyzed by respirometry, plate counts, and direct microscopic counts. Anaerobic microbial activity was

Barbara Orchard; Yarrow M. Nelson; Lynne Maloney; Christopher L. Kitts; Paul Lundegard

2005-01-01

113

Seed, soil, and beyond: The basic biology of brain metastasis.  

PubMed

First invoked by Paget, the seed and soil hypothesis suggests that the successful growth of metastatic cells depends on the interactions and properties of cancer cells (seeds) and their potential target organs (soil). In the context of the seed and soil hypothesis this review examines recent advances in the understanding of molecular and cellular features that permit transformed epithelial cells to gain access to the blood stream (intravasation), survive their journey through the blood stream, and ultimately traverse through the microvasculature of target organs (extravsation) to deposit, survive, and grow in a foreign tissue environment. In addition to a review of the clinical and experimental evidence supporting the seed and soil theory to cancer metastasis, additional concepts highlighted include: (i) The role of cancer stem-like cells as putative cells of metastatic origin (the "seeds"); (ii) the mechanism of epithelial to mesenchymal transition (EMT) in driving epithelial cell conthose molecules do no blood stream to avoid anoikis, or anchorage independent cell death; and (iv) the reverse process of EMT, or mesenchymal to epithelial transition (MET), which promotes conversion back to the parent cell morphology and growth of macrometastsis in the target organ. The unique biology of metastases once established in the brain, and in particular the "sanctuary" role that the brain microenvironment plays in promoting metastatic growth and treatment resistance, will also be examined. These issues are of more than academic interest since as systemic therapies gradually improve local tumor control, the relative impact of brain metastasis will inexorably play a proportionally greater role in determining patient morbidity and mortality. PMID:23717797

Ramakrishna, Rohan; Rostomily, Robert

2013-01-01

114

Biological Activity of Fenoxycarb Against 'Culex Quinquefasciatus'.  

National Technical Information Service (NTIS)

The biological activity of the newly developed carbamate insect growth regulator phenoxycarb was stuided on the immature and mature stages of Culex quinquefasciatus say phenoxycarb under laboratory conditions. The insecticide demonstrated larvicidal, pupi...

Z. H. Mohsen B. M. Al-Chalabi

1988-01-01

115

Structure and Biological Activity of the Streptococci.  

National Technical Information Service (NTIS)

Studies on the polysaccharide cell wall antigens of the streptococci has provided information on the methods of extraction, chemical composition and structure, relation of antigenic specificity to structure, and the biological activity of such polysacchar...

H. D. Slade

1975-01-01

116

Microbiological activity of soils populated by Lasius niger ants  

NASA Astrophysics Data System (ADS)

Ants are the most widespread colonial insects assigned to the Hymenoptera order. They actively use soil as a habitat; being numerous, they create a specific microrelief. It is shown that ants affect microbiological processes of the carbon and nitrogen cycles. The carbon content in anthills remains stable throughout the growing season, and the respiration intensity is about three times higher as compared with that in the control soil. The highest methane production (0.08 nmol of CH4/g per day) in the anthill is observed at the beginning of the growing season and exceeds that in the control soil by four times. The most active nitrogen fixation (about 4 nmol of C2H4/g per h) in the anthill takes place in the early growing season, whereas, in the control soil, it is observed in the middle of the growing season. At the same time, the diazotrophic activity is higher in the control soil. The lowest denitrification in the anthill is observed at the beginning and end of the growing season. The dynamics of the denitrification in the anthill are opposite to the dynamics of the diazotrophic activity. We suppose that these regularities of the biological activity in the anthill are related to the ecology of the ants and the changes in their food preferences during the growing season.

Golichenkov, M. V.; Neimatov, A. L.; Kiryushin, A. V.

2009-07-01

117

Heavy metal pollution and soil enzymatic activity  

Microsoft Academic Search

The activity of hydrolytic soil enzymes was studied on spruce mor, polluted with Cu and Zn from a brass foundry in Sweden. Approximately straight regression lines were obtained between enzymatic activity or respiration rate and log Cu+Zn concentration, with highly significant negative regression coefficients for urease and acid phosphatase activity as well as respiration rate, whereas ß-glucosidase activity was not

Germund Tyler

1974-01-01

118

Microbial activity in soils following steam treatment.  

PubMed

Steam enhanced extraction (SEE) is an aquifer remediation technique that can be effective at removing the bulk of non-aqueous phase liquid (NAPL) contamination from the subsurface, particularly highly volatile contaminants. However, low volatility compounds such as polynuclear aromatic hydrocarbons (PAHs) are less efficiently removed by this process. This research evaluated the effects of steam injection on soil microbial activity, community structure, and the potential for biodegradation of contaminants following steam treatment. Three different soils were evaluated: a laboratory-prepared microbially-enriched soil, soil from a creosote contaminated field site, and soil from a chlorinated solvent and waste oil contaminated field site. Results from field-scale steaming are also presented. Microbial activity before and after steam treatment was evaluated using direct epifluorescent microscopy (DEM) using the respiratory activity dye 5-cyano-2,3, ditolyl tetrazolium chloride (CTC) in conjunction with the fluorochrome 5-(4,6-dichlorotriazinyl) aminofluorescein (DTAF) to yield a quantitative assessment of active and total microbial numbers. DEM results indicate that steamed soils that were analyzed while still hot exhibited microbial activity levels that were below detection. However, soil samples that were slowly cooled, more closely reflecting the conditions of applied SEE, exhibited microbial activity levels that were comparable to presteamed soils. Samples from a field-site where steam was applied continuously for 6 weeks also showed high levels of microbial activity following cooling. The metabolic capabilities of the steamed communities were investigated by measuring cell growth in enrichment cultures on various substrates. These studies provided evidence that organisms capable of biodegradation were among the mesophilic populations that survived steam treatment. Fluorescent in situ hybridization (FISH) analysis of the soils with domain-level rRNA probes suggest that both Archaea and Bacteria survived steam exposure. PMID:12521292

Richardson, Ruth E; James, C Andrew; Bhupathiraju, Vishvesh K; Alvarez-Cohen, Lisa

2002-01-01

119

[Effects of heavy metals pollution on soil microbial communities metabolism and soil enzyme activities in coal mining area of Tongchuan, Shaanxi Province of Northwest China].  

PubMed

This paper studied the metabolism of soil microbes, functions of soil microbial communities, and activities of soil enzymes in a coal mining area of Tongchuan. In the coal mining area, the concentrations of soil Cu, Zn, Cd, and Pb were significantly higher than those in the non-mining area, of which, Cd contributed most to the heavy metals pollution. By adopting Biolog method combining with principal component analysis (PCA) and cluster analysis, it was found that the metabolic characteristics of different soil microbial communities varied significantly with increasing soil heavy metals pollution, and the variation was mainly manifested in the metabolic patterns of carbon sources such as saccharides and amino acids. In slightly and moderately polluted soils, the utilization of carbon sources by soil microbial communities was activated; while in heavily polluted soils, the carbon sources utilization was inhibited. The activities of soil urease, protease, alkaline phosphatase, and catalase all tended to decline with intensifying soil heavy metals pollution. The soil urease, protease, alkaline phosphatase, and catalase activities in the coal mining area were 50.5%-65.1%, 19.1%-57.1%, 87.2%-97.5%, and 77.3%-86.0% higher than those in the non-mining area, respectively. The activities of soil sucrase and cellulase were activated in slightly and moderately polluted soils, but inhibited in heavily polluted soils. PMID:22720628

Guo, Xing-Liang; Gu, Jie; Chen, Zhi-Xue; Gao, Hua; Qin, Qing-Jun; Sun, Wei; Zhang, Wei-Juan

2012-03-01

120

Persistence of biologically active compounds in aquatic systems: Final report  

SciTech Connect

Waters collected from two study sites were tested for persistence of biologically active compounds as the waters percolated through experimental media. At the first site, the Paraho Lysimeter in Anvil Points, Colorado, two leachate samples (early and late flow in Spring 1983) were collected from each of four piles of processed oil shale overlain by different thicknesses of soil. Although water quality differed among samples, six of eight lysimeter leachates tested were acutely toxic to an aquatic invertebrate, Daphnia magna, and five were acutely toxic to fathead minnows (Pimephales promelas). Water collected from a modified in situ (MIS) retort was percolated through columns containing three different types of soil. Raw leachate from the MIS spent shale was acutely toxic to an aquatic invertebrate, Ceriodaphnia dubia. The toxicity of samples from nine pore volumes of retort water percolating through a column containing a sandy soil increased with successive pore volumes, but leachate toxicity never equaled the toxicity of the retort water. In contrast, the first pore volumes of retort water or reconstituted water leached through a sandy loam soil were more toxic than the retort water; however, the second pore volumes of leachates were not toxic. First pore volume leachates of retort water percolating through a sandy clay loam soil were much less toxic than the retort water; second pore volume leachates were not toxic.

Boelter, A.M.; Fernandez, J.D.; Meyer, J.S.; Sanchez, D.A.; Bergman, H.L.

1986-11-01

121

“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

122

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.

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

2013-01-01

123

Elsholtzia: phytochemistry and biological activities  

PubMed Central

Plants of the genus Elsholtzia (Lamiaceae) have a long history of medicinal use in folk. The phytochemical investigations revealed the presence of flavonoids, phenylpropanoids, terpenoids, and other compounds. Abundant volatile components are also identified. Pure compounds, volatile constituents and crude extracts from the genus exhibited a wide spectrum of in vitro and in vivo pharmacological activities. The aims of this review hopefully provide comprehensive information on the distribution, phytochemistry, volatile components, and pharmacological research of Elsholtzia for exploring the potential and advance researches.

2012-01-01

124

Effect of sewage sludge on microbial biomass, basal respiration, metabolic quotient and soil enzymatic activity  

Microsoft Academic Search

Monitoring soil quality by means of biological indices can be of help for the management and sustainability of soils that received sewage sludge application. The objective of this study was to evaluate the effect of long-term and continued application of sewage sludge rates on microbial biomass, basal respiration, metabolic quotient and enzymatic activity of a Dark Red Dystroferric Latosol under

Silvana Aparecida Pavan Fernandes; Wagner Bettiol; Carlos Clementi Cerri

2005-01-01

125

Spatial variation of soil enzyme activities and microbial functional diversity in temperate alley cropping systems  

Microsoft Academic Search

Spatially dependent patterns in microbial properties may exist in temperate alley cropping systems due to differences in litter quality and microclimate in areas under trees compared to those in the alleys. The effect of tree row location was evaluated for its impact on soil enzyme activities and Biolog substrate use patterns. Soils were sampled to a depth of 30 cm at

Nancy W. Mungai; Peter P. Motavalli; Robert J. Kremer; Kelly A. Nelson

2005-01-01

126

Spatial Modeling of Biological Soil Crusts to Support Rangeland Assessment and Monitoring  

Microsoft Academic Search

Biological soil crusts are a diverse soil surface community, prevalent in semiarid regions, which function as ecosystem engineers and perform numerous important ecosystem services. Loss of crusts has been implicated as a factor leading to accelerated soil erosion and other forms of land degradation. To support assessment and monitoring efforts aimed at ensuring the sustainabil- ity of rangeland ecosystems, managers

Matthew A. Bowker; Jayne Belnap; Mark E. Miller

2006-01-01

127

Short term recovery of soil biological functions in a new vineyard cultivated in organic farming  

NASA Astrophysics Data System (ADS)

Deep earthwork activities carried out before vineyard plantation completely upset soil profile and characteristics. The resulting soil features are often much more similar to the underlying substratum than original soil profile. The time needed to recover soil functions is ecologically relevant and affects vine phenology and grape yield, particularly in organic viticulture. The general aim of this research work was to investigate the time needed to recover soil functions after the earthworks made before vine plantation. This study compared for a four years period physical and chemical properties, microbial and mesofauna communities, in new and old vineyards, cultivated on the same soil type. The experiment was conducted in a farm of the Chianti Classico district (Central Italy), on hills of high altitude (400-500 m a.s.l.) on clayey-calcareous flysches, with stony and calcareous soils (Haplic Cambisol (Calcaric, Skeletic)). The reference vine cultivar was Sangiovese. The older vineyard was planted in 2000, after slope reshaping by bulldozing and back hoe ploughing down to about 0.8-1.0 m. The new vineyard was planted in 2011 after an equivalent earthwork carried out in the summer of 2009. Both vineyards were organically managed and only compost at the rate of 1,000 kg ha-1 -a was added every year. The new vineyard was periodically cultivated by mechanical tillage, while the older only at alternate rows. Soil samples from the first 15 cm depth were collected in 4 replicates in the younger as well as in the older vineyard during the springtime of 2010-2013; in the older vineyard, two samples were from the periodically cultivated swaths and two under permanent grass cover. Samples were analysed for physical (particle size, field capacity, wilting point), chemical (pH, electrical conductivity, lime, active lime, organic carbon, total nitrogen), microbiological (soil respiration, microbial biomass, DGGE), and mesofauna features (abundance, taxa richness, BSQ index and soil biological classes). Physical soil characteristics remained unchanged after the first year from the earthworks and did not change under grass cover. Chemical analysis only indicated a significant effect of earthworks. Over the 2010-2013 period, the new vineyard showed a slight increase of TOC and total N contents; as compared to the old vineyard, it averaged lower TOC and total N, and higher CaCO3 contents, suggesting still evolving equilibrium conditions. Microarthropod analysis showed significant different abundances and communities' structures both by management system and by year, increasing where the land use pressure was reduced by permanent grass cover and along with the aging of vineyard. Though the euedaphic forms, well adapted to soil life, were always rare. Microbiological analysis showed a different structure of eubacterial communities and a lower microbial activity in the new vineyard, especially during 2010-2012. In contrast, significant differences were not observed between the two vineyards in 2013, and grass cover effect was controversial. To sum up, the consequence of deep earthworks on chemical and biological properties were still evident after four years from planting and more time was needed to recover soil functions. Permanent grass cover did not always show a consistent positive effect.

Costantini, Edoardo; Agnelli, Alessandro; Fabiani, Arturo; Gagnarli, Elena; Mocali, Stefano; Priori, Simone; Simoni, Sauro; Valboa, Giuseppe

2014-05-01

128

PCB disposition and different biological effects in rats following direct soil exposure vs. PCBs off-gassed from the soil  

Microsoft Academic Search

A comparison of PCB congener profiles and limited biological effects was made between direct exposure to PCB-contaminated soil and vapor phase PCBs from that soil to determine congener patterns useful for identifying exposure sources in humans and wildlife. Weanling female Sprague–Dawley rats were exposed to either control or PCB-contaminated soil (from a landfill in Southern Illinois) for 1 and 2

K Imsilp; D. J Schaeffer; L. G Hansen

2005-01-01

129

Phenol oxidase activity in secondary transformed peat-moorsh soils  

NASA Astrophysics Data System (ADS)

The chemical composition of peat depends on the geobotanical conditions of its formation and on the depth of sampling. The evolution of hydrogenic peat soils is closely related to the genesis of peat and to the changes in water conditions. Due to a number of factors including oscillation of ground water level, different redox potential, changes of aerobic conditions, different plant communities, and root exudes, and products of the degradation of plant remains, peat-moorsh soils may undergo a process of secondary transformation conditions (Sokolowska et al. 2005; Szajdak et al. 2007). Phenol oxidase is one of the few enzymes able to degrade recalcitrant phenolic materials as lignin (Freeman et al. 2004). Phenol oxidase enzymes catalyze polyphenol oxidation in the presence of oxygen (O2) by removing phenolic hydrogen or hydrogenes to from radicals or quinines. These products undergo nucleophilic addition reactions in the presence or absence of free - NH2 group with the eventual production of humic acid-like polymers. The presence of phenol oxidase in soil environments is important in the formation of humic substances a desirable process because the carbon is stored in a stable form (Matocha et al. 2004). The investigations were carried out on the transect of peatland 4.5 km long, located in the Agroecological Landscape Park host D. Chlapowski in Turew (40 km South-West of Pozna?, West Polish Lowland). The sites of investigation were located along Wysko? ditch. The following material was taken from four chosen sites marked as Zbechy, Bridge, Shelterbelt and Hirudo in two layers: cartel (0-50cm) and cattle (50-100cm). The object of this study was to characterize the biochemical properties by the determination of the phenol oxidize activity in two layers of the four different peat-moors soils used as meadow. The phenol oxidase activity was determined spectrophotometrically by measuring quinone formation at ?max=525 nm with catechol as substrate by method of Perucci et al. (2000). In peat the highest activities of phenol oxidase was observed in the combinations marked as Shelterbelt and whereas the lowest - in Zbechy, Bridge and Hirudo. Activities of this enzyme in peat ranged from 15.35 to 38.33 ?mol h-1g d.m soil. Increased activities of phenol oxidase have been recorded on the depth 50-100cm - catotelm (21.74-38.33 ?mol h-1g d.m soil) in comparison with the depth 0-50cm - acrotelm (15.35-28.32 ?mol h-1g d.m soil). References Freeman, C., Ostle N.J., Fener, N., Kang H. 2004. A regulatory role for phenol oxidase during decomposition in peatlands. Soil Biology and Biochemistry, 36, 1663-1667. Matocha Ch.J., Haszler G.R., Grove J.H. 2004. Nitrogen fertilization suppresses soil phenol oxidase enzyme activity in no-tillage systems. Soil Science, 169/10, 708-714. Perucci P., Casucci C., Dumontet S. 2000. An improved method to evaluate the o-diphenol oxidase activity of soil. Soil Biology and Biochemistry, 32, 1927-1933. Sokolowska Z., Szajdak L., Matyka-Sarzy?ska D. 2005. Impact of the degree of secondary transformation on amid-base properties of organic compounds in mucks. Geoderma, 127, 80-90. Szajdak L., Szczepa?ski M., Bogacz A. 2007. Impact of secondary transformation of peat-moorsh soils on the decrease of nitrogen and carbon compounds in ground water. Agronomy Research, 5/2, 189-200.

Sty?a, K.; Szajdak, L.

2009-04-01

130

Marine Biology Activities. Ocean Related Curriculum Activities.  

ERIC Educational Resources Information Center

The ocean affects all of our lives. Therefore, awareness of and information about the interconnections between humans and oceans are prerequisites to making sound decisions for the future. Project ORCA (Ocean Related Curriculum Activities) has developed interdisciplinary curriculum materials designed to meet the needs of students and teachers…

Pauls, John

131

Biological removal of arsenic pollution by soil fungi.  

PubMed

Fifteen fungal strains were isolated from arsenic contaminated (range 9.45-15.63 mg kg(-1)) agricultural soils from the state of West Bengal, India. Five fungal strains were belonged to the Aspergillus and Trichoderma group each, however, remaining five were identified as the Neocosmospora, Sordaria, Rhizopus, Penicillium and sterile mycelial strain. All these fungal strains were cultivated on medium supplemented with 100, 500, 1000, 5000 and 10,000 mg l(-1) of sodium arsenate. After 30-day cultivation under laboratory conditions, radial growth of these strains was determined and compared with control. Toxicity and tolerance of these strains to arsenate were evaluated on the basis of tolerance index. Out of fifteen, only five fungal strains were found resistant and survived with tolerance index pattern as 0.956 (sterile mycelial strain)>0.311 (Rhizopus sp.)>0.306 (Neocosmospora sp.)>0.212 (Penicillium sp.)>0.189 (Aspergillus sp.) at 10,000 mg l(-1) of arsenate. The arsenic removal efficacy of ten fungal strains, tolerant to 5000 mg l(-1) arsenate, was also assayed under laboratory conditions for 21 days. All these strains were cultivated individually on mycological broth enriched with 10 mg l(-1) of arsenic. The initial and final pH of cultivating medium, fungal biomass and removal of arsenic by each fungal strain were evaluated. Fungal biomass of ten strains removed arsenic biologically from the medium which were ranged from 10.92 to 65.81% depending on fungal species. The flux of biovolatilized arsenic was determined indirectly by estimating the sum of arsenic content in fungal biomass and medium. The mean percent removal as flux of biovolatilized arsenic ranged from 3.71 to 29.86%. The most effective removal of arsenic was observed in the Trichoderma sp., sterile mycelial strain, Neocosmospora sp. and Rhizopus sp. fungal strains. These fungal strains can be effectively used for the bioremediation of arsenic-contaminated agricultural soils. PMID:21459413

Srivastava, Pankaj Kumar; Vaish, Aradhana; Dwivedi, Sanjay; Chakrabarty, Debasis; Singh, Nandita; Tripathi, Rudra Deo

2011-05-15

132

Bioremediation of pentachlorophenol-contaminated soil by bioaugmentation using activated soil  

Microsoft Academic Search

The use of an indigenous microbial consortium, pollutant-acclimated and attached to soil particles (activated soil), was\\u000a studied as a bioaugmentation method for the aerobic biodegradation of pentachlorophenol (PCP) in a contaminated soil. A 125-l\\u000a completely mixed soil slurry (10% soil) bioreactor was used to produce the activated soil biomass. Results showed that the\\u000a bioreactor was very effective in producing a

C. Barbeau; L. Deschênes; D. Karamanev; Y. Comeau; R. Samson

1997-01-01

133

Glycosides from marine sponges (Porifera, Demospongiae): structures, taxonomical distribution, biological activities and biological roles.  

PubMed

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

2012-08-01

134

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.

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

2012-01-01

135

l-Asparaginase activity of soils  

Microsoft Academic Search

A simple, precise, and sensitive method to assay l-asparaginase (l-asparagine amidohydrolase, EC 3.5.1.1) activity in soils is described. This method use steam distillation to determine the NHinf4sup+produced by l-asparaginase activity when soil is incubated with buffered (0.1 M THAM, pH 10) l-asparagine solution and toluene at 30°C for 2 h. The procedure developed gives quantitative recovery of NHinf4sup+-N added to

W. T. Frankenberger; M. A. Tabatabai

1991-01-01

136

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

137

Carbon and nitrogen fixation differ between successional stages of biological soil crusts in the Colorado Plateau and Chihuahuan Desert  

USGS Publications Warehouse

Biological soil crusts (cyanobacteria, mosses and lichens collectively) perform essential ecosystem services, including carbon (C) and nitrogen (N) fixation. Climate and land-use change are converting later successional soil crusts to early successional soil crusts with lower C and N fixation rates. To quantify the effect of such conversions on C and N dynamics in desert ecosystems we seasonally measured diurnal fixation rates in different biological soil crusts. We classified plots on the Colorado Plateau (Canyonlands) and Chihuahuan Desert (Jornada) as early (Microcoleus) or later successional (Nostoc/Scytonema or Placidium/Collema) and measured photosynthesis (Pn), nitrogenase activity (NA), and chlorophyll fluorescence (Fv/Fm) on metabolically active (moist) soil crusts. Later successional crusts typically had greater Pn, averaging 1.2-1.3-fold higher daily C fixation in Canyonlands and 2.4-2.8-fold higher in the Jornada. Later successional crusts also had greater NA, averaging 1.3-7.5-fold higher daily N fixation in Canyonlands and 1.3-25.0-fold higher in the Jornada. Mean daily Fv/Fm was also greater in later successional Canyonlands crusts during winter, and Jornada crusts during all seasons except summer. Together these findings indicate conversion of soil crusts back to early successional stages results in large reductions of C and N inputs into these ecosystems.

Housman, D. C.; Powers, H. H.; Collins, A. D.; Belnap, J.

2006-01-01

138

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

139

Interactions Between Xenobiotics and Microbial and Enzymatic Soil Activity  

Microsoft Academic Search

In the second half of the twentieth century, the indiscriminate release of xenobiotic chemicals of different chemical and structural complexity into the environment provoked serious and most often irreversible alterations of the natural environmental balance. Indeed, soil contamination by highly toxic compounds has greatly increased, with negative, irreversible effects on soil quality and health. Several chemical, biological, and biochemical soil

Liliana Gianfreda; Maria A. Rao

2008-01-01

140

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

141

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

USGS Publications Warehouse

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 soil crusts on mineral uptake of associated vascular plants is known. These new case studies, and others previously published, demonstrate that cyanobacterial or cyanobacteria- Collema crusts significantly alter uptake by plants of many bioessential elements. In studies now available, these crusts always increase the N content of associated seed plants. Uptake of Cu, K, Mg, and Zn is usually (>70% of reported cases) increased in the presence of the biological soil crusts. Soil crusts are generally negatively associated with Fe and P levels in associated seed plant tissue, while plant tissue levels of Ca, Mn, and Na are positively as often as negatively associated with the presence of soil crusts. Increases in bioessential elements in vascular plant tissue from biologically-crusted areas are greatest for short-lived herbs that are rooted primarily within the surface soil, the horizon most influenced by crustal organisms. The mineral content of a deeply rooted shrub (Coleogyne ramosissima) was less influenced by co-occurrence of biological soil crusts.

Harper, K. T.; Belnap, Jayne

2001-01-01

142

Increased temperature and altered summer precipitation have differential effects on biological soil crusts in a dryland ecosystem  

USGS Publications Warehouse

Biological soil crusts (biocrusts) are common and ecologically important members of dryland ecosystems worldwide, where they stabilize soil surfaces and contribute newly fixed C and N to soils. To test the impacts of predicted climate change scenarios on biocrusts in a dryland ecosystem, the effects of a 2–3 °C increase in soil temperature and an increased frequency of smaller summer precipitation events were examined in a large, replicated field study conducted in the cold desert of the Colorado Plateau, USA. Surface soil biomass (DNA concentration), photosynthetically active cyanobacterial biomass (chlorophyll a concentration), cyanobacterial abundance (quantitative PCR assay), and bacterial community composition (16S rRNA gene sequencing) were monitored seasonally over 2 years. Soil microbial biomass and bacterial community composition were highly stratified between the 0–2 cm depth biocrusts and 5–10 cm depth soil beneath the biocrusts. The increase in temperature did not have a detectable effect on any of the measured parameters over 2 years. However, after the second summer of altered summer precipitation pattern, significant declines occurred in the surface soil biomass (avg. DNA concentration declined 38%), photosynthetic cyanobacterial biomass (avg. chlorophyll a concentration declined 78%), cyanobacterial abundance (avg. gene copies g?1 soil declined 95%), and proportion of Cyanobacteria in the biocrust bacterial community (avg. representation in sequence libraries declined 85%). Biocrusts are important contributors to soil stability, soil C and N stores, and plant performance, and the loss or reduction of biocrusts under an altered precipitation pattern associated with climate change could contribute significantly to lower soil fertility and increased erosion and dust production in dryland ecosystems at a regional scale.

Johnson, Shannon L.; Kuske, Cheryl R.; Carney, Travis D.; Housman, David C.; Gallegos-Graves, La Verne; Belnap, Jayne

2012-01-01

143

Microbial activity in soils following steam treatment  

Microsoft Academic Search

Steam enhanced extraction (SEE) is an aquifer remediation technique that can be effective at removing the bulk of non-aqueous phase liquid (NAPL) contamination from the subsurface, particularly highly volatile contaminants. However, low volatility compounds such as polynuclear aromatic hydrocarbons (PAHs) are less efficiently removed by this process. This research evaluated the effects of steam injection on soil microbial activity, community

Ruth E. Richardson; C. Andrew James; Vishvesh K. Bhupathiraju; Lisa Alvarez-Cohen

2002-01-01

144

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.

145

Effects of Prochloraz fungicide on soil enzymatic activities and bacterial communities.  

PubMed

We studied in the laboratory the effect of Prochloraz fungicide on the biological properties (soil enzymatic activities and soil bacterial communities) of a Plaggic Anthrosol. Five hundred grams of soil (<2mm) was mixed with three dosages of Prochloraz (1, 2, and 4 l ha(-1)) for 83 days. A non-Prochloraz polluted soil was used as control. Following commercial recommendations, fungicide was applied four times during the incubation experiment. For all treatments, the soil ergosterol and levels of dehydrogenase, urease, ?-glucosidase, and phosphatase activity were measured at nine different times (0, 1, 21, 22, 41, 42, 62, 63, and 83 days). The 16S rDNA-DGGE profiles in all treatments were determined at the beginning and end of the incubation period. At the end of the experiment, a significant decrease in ergosterol by 72.3%, 80.8%, and 83.1%, compared with control soil, was observed when 1, 2, and 4 l ha(-1), respectively, was added. Soil enzymatic activities increased when the Prochloraz applied to the soil increased, possibly because the fungicide is used by bacterial communities as a source of energy and nutrients. The 16S rDNA-DGGE profiles indicated that the fungicide did not negatively affect soil bacterial biodiversity. These results suggested that the fungicide Prochloraz has a very interesting agronomic effect, possibly due to the negative effect on soil fungal population stimulating the growth of soil bacterial activity. PMID:21596437

Tejada, Manuel; Gómez, Isidoro; García-Martínez, Ana María; Osta, Paloma; Parrado, Juan

2011-09-01

146

Isoflavones: estrogenic activity, biological effect and bioavailability.  

PubMed

Isoflavones are phytoestrogens with potent estrogenic activity; genistein, daidzein and glycitein are the most active isoflavones found in soy beans. Phytoestrogens have similarity in structure with the human female hormone 17-?-estradiol, which can bind to both alpha and beta estrogen receptors, and mimic the action of estrogens on target organs, thereby exerting many health benefits when used in some hormone-dependent diseases. Numerous clinical studies claim benefits of genistein and daidzein in chemoprevention of breast and prostate cancer, cardiovascular disease and osteoporosis as well as in relieving postmenopausal symptoms. The ability of isoflavones to prevent cancer and other chronic diseases largely depends on pharmacokinetic properties of these compounds, in particular absorption and distribution to the target tissue. The chemical form in which isoflavones occur is important because it influences their bioavailability and, therefore, their biological activity. Glucose-conjugated isoflavones are highly polar, water-soluble compounds. They are hardly absorbed by the intestinal epithelium and have weaker biological activities than the corresponding aglycone. Different microbial families of colon can transform glycosylated isoflavones into aglycones. Clinical studies show important differences between the aglycone and conjugated forms of genistein and daidzein. The evaluation of isoflavone metabolism and bioavailability is crucial to understanding their biological effects. Lipid-based formulations such as drug incorporation into oils, emulsions and self-microemulsifying formulations have been introduced to increase bioavailability. Complexation with cyclodextrin also represent a valid method to improve the physicochemical characteristics of these substances in order to be absorbed and distributed to target tissues. We review and discuss pharmacokinetic issues that critically influence the biological activity of isoflavones. PMID:23161396

Vitale, Daniela Cristina; Piazza, Cateno; Melilli, Barbara; Drago, Filippo; Salomone, Salvatore

2013-03-01

147

Soil moisture pre-treatment effects on enzyme activities as indicators of heavy metal-contaminated and reclaimed soils  

Microsoft Academic Search

Heavy metal contamination can inhibit soil functions but it is often difficult to determine the degree of pollution or when soil reclamation is complete. Enzyme assays offer potential as indicators of biological functioning of soils. However, antecedent water content of soil samples may affect the outcome of biological measurements. In Mediterranean regions, for much of the year ‘field moist’ surface

M. Belén Hinojosa; José A. Carreira; Roberto García-Ruíz; Richard P. Dick

2004-01-01

148

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...

149

Adsorption, Movement, and Biological Degradation of Large Concentrations of Selected Pesticides in Soils.  

National Technical Information Service (NTIS)

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...

J. M. Davidson P. S. C. Rao L. T. Ou W. B. Wheeler D. F. Rothwell

1980-01-01

150

Decontaminazione di suoli mediante processi biologici. (Soil decontamination using biological processes (bioremediation)).  

National Technical Information Service (NTIS)

Bioremediation, the use of biological processes to detoxify polluted soils, is not a new technique, but now it is arousing a renewed interest and the practical applications outline that bioremediation is a very promising technique. Microorganisms are the ...

A. R. Sprocati

1994-01-01

151

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

152

Biologically active compounds from Aphyllophorales (polypore) fungi.  

PubMed

This review describes biologically active natural products isolated from Aphyllophorales, many of which are known as polypores. Polypores are a large group of terrestrial fungi of the phylum Basdiomycota (basidiomycetes), and they along with certain Ascomycota are a major source of pharmacologically active substances. There are about 25 000 species of basidiomycetes, of which about 500 are members of the Aphyllophorales, a polyphyletic group that contains the polypores. Many of these fungi have circumboreal distributions in North America, Europe, and Asia and broad distributions on all inhabited continents and Africa; only a small number of the most common species with the most obvious fruiting bodies (basidiocarps) have been evaluated for biological activity. An estimated 75% of polypore fungi that have been tested show strong antimicrobial activity, and these may constitute a good source for developing new antibiotics. Numerous compounds from these fungi also display antiviral, cytotoxic, and/or antineoplastic activities. Additional important components of this vast arsenal of compounds are polysaccharides derived from the fungal cell walls. These compounds have attracted significant attention in recent years because of their immunomodulatory activities, resulting in antitumor effects. These high molecular weight compounds, often called biological response modifiers (BRM), or immunopotentiators, prevent carcinogenesis, show direct anticancer effects, and prevent tumor metastasis. Some of the protein-bound polysaccharides from polypores and other basidiomycetes have found their way to the market in Japan as anticancer drugs. Finally, numerous compounds with cardiovascular, phytotoxic, immunomodulatory, analgesic, antidiabetic, antioxidant, insecticidal, and nematocidal activities, isolated from polypores, are also presented. In fact many of the fungi mentioned in this paper have long been used in herbal medicine, including polypores such as Ganoderma lucidum (Reishi or Ling Zhi), Laetiporus sulphureus (Chicken-of-the-Woods), Trametes versicolor (Yun Zhi), Grifola umbellata (Zhu Lin), Inonotus obliquus (Chaga), and Wolfiporia cocos (Hoelen). PMID:14987072

Zjawiony, Jordan K

2004-02-01

153

Biologically active polysaccharides as possible lead compounds  

Microsoft Academic Search

Various carbohydrate polymers have during the last decades been shown to be responsible for biological effects, either by\\u000a exhibiting the effect themselves or by inducing effects via complex reaction cascades. These are e.g. anti-inflammatory, immunostimulating,\\u000a complement activation, antithrombotic, antidiabetic and infection protectant. Modern pharmaceutical industry has extensive\\u000a research programs where the aim is to obtain information on traditional use of

Berit Smestad Paulsen

2002-01-01

154

Biological and physical influences on soil 14CO2 seasonal dynamics in a temperate hardwood forest  

NASA Astrophysics Data System (ADS)

While radiocarbon (14C) abundance in standing stocks of soil carbon has been used to evaluate rates of soil carbon turnover on timescales of several years to centuries, soil-respired 14CO2 measurements are an important tool for identifying more immediate responses to disturbance and climate change. Soil 14CO2 data are often temporally sparse, however, and could be interpreted better with more context for typical seasonal ranges and trends. We report on a semi-high-frequency sampling campaign to distinguish physical and biological drivers of soil 14CO2 at a temperate forest site in Northern Wisconsin, USA. We sampled 14CO2 profiles every three weeks during snow-free months through 2012, in three intact plots and one trenched plot that excluded roots. Respired 14CO2 declined through the summer in intact plots, shifting from an older C composition that contained more bomb 14C, to a younger composition more closely resembling present 14C levels in the atmosphere. In the trenched plot respired 14C was variable but remained comparatively higher than in intact plots, reflecting older bomb-enriched 14C sources. Although respired 14CO2 from intact plots correlated with soil moisture, related analyses did not support a clear cause-and-effect relationship with moisture. The initial decrease in 14CO2 from spring to midsummer could be explained by increases in 14C-deplete root respiration; however, 14CO2 continued to decline in late summer after root activity decreased. We also investigated whether soil moisture impacted vertical partitioning of CO2 production, but found this had little effect on respired 14CO2 because CO2 contained modern bomb-C at depth, even in the trenched plot. This surprising result contrasted with decades to centuries-old pre-bomb CO2 produced in lab incubations of the same soils. Our results suggest that root-derived C and other recent C sources had dominant impacts on 14CO2 in situ, even at depth. We propose that 14CO2 may have declined through late summer in intact plots because of continued microbial turnover of root-derived C, following declines in root respiration. Our results agree with other studies showing large seasonal fluctuations in respired ?14CO2, and suggest root C inputs are an important driver.

Phillips, C. L.; McFarlane, K. J.; Risk, D.; Desai, A. R.

2013-07-01

155

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.

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

2010-01-01

156

Biologically induced accumulations of CaCO 3 in orthox soils of Biga, Ivory Coast  

Microsoft Academic Search

Biologically induced accumulations of calcium carbonate have been found inside orthox soils, under and around the native iroko tree Milicia excelsa (Moraceae) in Biga (Ivory Coast). The nature of these accumulations and their origin were studied in two soil profiles, directly under the tree and at a distance of 30 cm from the trunk. Microscale forms of CaCO3 include: (1)

Guillaume Cailleau; Olivier Braissant; Christophe Dupraz; Michel Aragno; Eric P. Verrecchia

2005-01-01

157

Role of organic acids in the mechanisms of biological soil disinfestation (BSD)  

Microsoft Academic Search

Biological soil disinfestation (BSD), or reductive soil disinfestation, achieved by amendment with organic materials such\\u000a as wheat bran followed by flooding and covering the soil surface, has been used to control some soilborne diseases including\\u000a Fusarium wilt and bacterial wilt of tomato. During a BSD treatment, accumulation of acetic acid and\\/or butyric acid was detected\\u000a with high-performance liquid chromatography. Survival

Noriaki Momma; Kazuhiro Yamamoto; Peter Simandi; Masahiro Shishido

2006-01-01

158

Effect of biological soil crusts on soil elemental concentrations: implications for biogeochemistry and as traceable biosignatures of ancient life on land  

Microsoft Academic Search

Biological soil crusts (BSCs) are topsoil biosedimentary structures built by photosynthetic microbes commonly found today on arid soils. They play a role in soil stabilization and the fertility of arid lands, and are considered modern analogues of ancient terrestrial microbial communities. We determined the concentrations of four biogenic and 21 other elements, mostly metals, in surface soils that hosted BSCs,

H. BERALDI-CAMPESI; H. E. HARTNETT; A. ANBAR; G. W. GORDON; F. GARCIA-PICHEL

2009-01-01

159

Biological surfactant production in a biological slurry reactor treating diesel fuel contaminated soil.  

PubMed

A sandy loam with aged diesel fuel contamination was treated for 90 days in an 8-L soil slurry-sequencing batch reactor (SS-SBR). The purpose was to investigate biological surfactant production and its effect on slurry properties and reactor performance. The SS-SBR was operated with a 10-day retention time and a 5-day cycle. Track studies were performed to monitor the fluctuation in slurry properties during a single cycle. Surfactants were produced faster than they were degraded or sorbed during the first 1.5 days of each cycle, resulting in increasing concentrations from less than the critical micelle concentration (CMC) to 60 times the CMC and an increase in aqueous diesel fuel concentration from 0 to 1.2 g/L. Only after the concentration of surfactants and emulsified diesel fuel began to decrease through biodegradation (after 1.5 days) was foaming observed. Foam thickness increased from 0 mm at 1.5 days to 48 mm on day 3, and then decreased to 0 mm again by the end of the cycle. Surfactants were completely degraded by the end of each cycle. Coinciding profiles of foam thickness and emulsification capacity (i.e., ability to emulsify spiked hydrocarbon) indicate that foaming resulted from the temporary accumulation of free surfactant molecules. Biological surfactant production occurred without cell multiplication during the first day, but was later growth associated. The ratio of oxygen to diesel fuel consumed was 1.7, and the microorganism yield on a chemical oxygen demand basis (YCOD) was 0.43. PMID:11558308

Cassidy, D P

2001-01-01

160

Effects of soil properties and trace metals on urease activities of calcareous soils  

Microsoft Academic Search

A study was conducted to investigate the relationship between urease activity and some physical, chemical, and microbiological properties of soils from central Iran. Inhibitory effects of Cr, Cd, and Pb on urease activity were also studied. Results indicated that no significant difference was observed between urease activity of field-moist and air-dried soils. Soil organic C and total N correlated highly

Farshid Nourbakhsh; Carlos M. Monreal

2004-01-01

161

Revisiting classic water erosion models in drylands: The strong impact of biological soil crusts  

USGS Publications Warehouse

Soil erosion and subsequent degradation has been a contributor to societal collapse in the past and is one of the major expressions of desertification in arid regions. The revised universal soil loss equation (RUSLE) models soil lost to water erosion as a function of climate erosivity (the degree to which rainfall can result in erosion), topography, soil erodibility, and land use/management. The soil erodibility factor (K) is primarily based upon inherent soil properties (those which change slowly or not at all) such as soil texture and organic matter content, while the cover/management factor (C) is based on several parameters including biological soil crust (BSC) cover. We examined the effect of two more precise indicators of BSC development, chlorophyll a and exopolysaccharides (EPS), upon soil stability, which is closely inversely related to soil loss in an erosion event. To examine the relative influence of these elements of the C factor to the K factor, we conducted our investigation across eight strongly differing soils in the 0.8 million ha Grand Staircase-Escalante National Monument. We found that within every soil group, chlorophyll a was a moderate to excellent predictor of soil stability (R2 = 0.21-0.75), and consistently better than EPS. Using a simple structural equation model, we explained over half of the variance in soil stability and determined that the direct effect of chlorophyll a was 3?? more important than soil group in determining soil stability. Our results suggest that, holding the intensity of erosive forces constant, the acceleration or reduction of soil erosion in arid landscapes will primarily be an outcome of management practices. This is because the factor which is most influential to soil erosion, BSC development, is also among the most manageable, implying that water erosion in drylands has a solution. ?? 2008 Elsevier Ltd.

Bowker, M. A.; Belnap, J.; Bala, Chaudhary, V.; Johnson, N. C.

2008-01-01

162

Soil enzyme activities as affected by anthropogenic alterations: intensive agricultural practices and organic pollution.  

PubMed

The activity of a range of enzymes related to the cycling of the main biologically important nutrients C, N, P and S was investigated in cultivated and non-cultivated soils from various parts of Europe. Two agricultural sites from North Italy under continuous corn (Zea mays L.) with and without organic fertilization were compared. Two other agricultural sites from South Italy under hazel (Corylus avellana L.) never flooded or repeatedly flooded over by uncontrolled urban and industrial wastes were investigated. The non-cultivated soils were from Middle and South Europe with different pollution history such as no-pollution and pollution with organic contaminants, which is phenanthrene and other polycyclic aromatic hydrocarbons (PAHs). Agricultural soils showed significant differences in some of physical-chemical properties (i.e. organic C, total and labile phosphate contents, available Ca and Mg) between the two sites studied. Enzyme activities of hazel sites periodically flooded by wastes were mainly higher than in the hazel sites never flooded. Sites under many years of continuous corn showed dehydrogenase, invertase, arylsulphatase and beta-glucosidase activities generally lower than the soils under hazel either flooded or not by wastes. As compared to agricultural soils, non-cultivated soils heavily or moderately polluted by organic contaminants displayed much lower values or complete absence of enzymatic activities. Dissimilar, contradictory correlations between soil enzyme activities and the majority of soil properties were observed separately in the two groups of soils. When the whole set of enzyme activities and soil properties were considered, all significant correlations found separately for the groups of soils were lost. The overall results seem to confirm that no direct cause-effect relationships can be derived between the changes of a soil in response to a given factor and both the variations of the activity and the behaviour of the enzymes in soil. PMID:15833257

Gianfreda, Liliana; Antonietta Rao, Maria; Piotrowska, Anna; Palumbo, Giuseppe; Colombo, Claudio

2005-04-01

163

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.

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

2014-01-01

164

Daily dynamics of cellulase activity in arable soils depending on management practices  

NASA Astrophysics Data System (ADS)

The daily dynamics of cellulase activity was studied during 27 days by the cellophane membrane method on soils managed using the conventional high-input farming system (application of mineral fertilizers and pesticides) and the biological conservation farming system (application of organic fertilizers alone) in a microfield experiment. The regular oscillatory dynamics of the cellulase activity were revealed and confirmed by the harmonic (Fourier) analysis. The oscillatory dynamics of the cellulase activity had a self-oscillatory nature and was not directly caused by the disturbing impacts of both the uncontrolled (natural) changes in the temperature and moisture (rainfall) and the controlled ones (the application of different fertilizers). The disturbing impacts affected the oscillation amplitude of the cellulase activity but not the frequency (periods) of the oscillations. The periodic oscillations of the cellulase activity were more significant in the soil under the high-input management compared to the soil under the biological farming system.

Lavrent'eva, E. V.; Semenov, A. M.; Zelenev, V. V.; Chzhun, Yu.; Semenova, E. V.; Semenov, V. M.; Namsaraev, B. B.; van Bruggen, A. H. C.

2009-08-01

165

Biological Treatment of Petroleum in Radiologically Contaminated Soil  

SciTech Connect

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 the levels to less than 100 mg/kg in 22 months. After treatment, the soils were permanently disposed as low-level radiological waste. The petroleum and radiologically contaminated soil (PRCS) bioreactor operated using bioventing to control the supply of oxygen (air) to the soil being treated. The system treated 3.67 tons of PCRS amended with weathered compost, ammonium nitrate, fertilizer, and water. In addition, a consortium of microbes (patent pending) isolated at the Savannah River National Laboratory from a petroleum-contaminated site was added to the PRCS system. During operation, degradation of petroleum waste was accounted for through monitoring of carbon dioxide levels in the system effluent. The project demonstrated that co-contaminated soils could be successfully treated through bioventing and bioaugmentation to remove petroleum contamination to levels below 100 mg/kg while protecting workers and the environment from radiological contamination.

BERRY, CHRISTOPHER

2005-11-14

166

Arbuscular mycorrhizas and biological control of soil-borne plant pathogens – an overview of the mechanisms involved  

Microsoft Academic Search

Biological control of plant pathogens is currently accepted as a key practice in sustainable agriculture because it is based\\u000a on the management of a natural resource, i.e. certain rhizosphere organisms, common components of ecosystems, known to develop\\u000a antagonistic activities against harmful organisms (bacteria, fungi, nematodes etc.). Arbuscular mycorrhizal (AM) associations\\u000a have been shown to reduce damage caused by soil-borne plant

C. Azcón-Aguilar; J. M. Barea

1997-01-01

167

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

168

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.

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

2010-01-01

169

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

170

Effect of Alkalized Phosphogypsum on Soil Chemical and Biological Properties  

Microsoft Academic Search

Phosphogypsum (PG) was mixed with calcium hydroxide [Ca(OH)2], ranging from 0 to 5%, to determine the optimal amount of Ca(OH)2 required to alkalize the acidity of PG. The alkalized PG by 4% of Ca(OH)2 addition was selected for field tests to evaluate the effects of alkalized PG on soil microbial, chemical properties, and yield of Chinese cabbage. Soil pH increased

Chang Hoon Lee; Byung Yeon Ha; Yong Bok Lee; Pil Joo Kim

2009-01-01

171

Soil Moisture Active-Passive Mission (SMAP)  

NASA Astrophysics Data System (ADS)

NASA plans to launch the Soil Moisture Active-Passive (SMAP) Satellite in 2012 as the initial mission in response to the National Academy's Earth Science and Applications From Space — National Imperatives for the Next Decade and Beyond. The goals of the SMAP mission are to measure near-surface soil moisture and its freeze/thaw state. The mission will combine both active and passive remote sensing techniques using the L-band channel. This will allow for spatial resolutions on the order of ten kilometers near global coverage with 2-3 day repeat times and an accuracy of roughly 4% for volumetric soil moisture. Through this new level of a combined capabilities and an ability to sense through moderate levels of vegetation, the mission will make large contributions to science by: 1) providing for improvements in estimates of land surface evaporation, 2) improving our understanding of land-atmosphere water and energy exchange, and 3) helping to determine the transition of boreal ecosystems between carbon sink and source regions. The mission will also provide valuable information to decision makers, by improving capabilities to predict, detect, and evaluate floods and droughts. The SMAP project enjoys a lot of heritage: 1) mission planning through the Hydros Project, 2) satellite instrumentation from Aquarius, 3) numerous field campaign activities to evaluate soil moisture remote sensing techniques (e.g. SMEXs, SGPs, etc.), and 4) significant community research in data assimilation of soil moisture (e.g. LDAS, JCSDA, etc). This final aspect, which includes much ongoing work, should enable the use of SMAP's soil moisture data, in near real-time, soon after launch. The data is expected to be useful to weather forecasting by the National Weather Service and potentially ECMWF, and short-term climate predications by numerous groups, including NASA's Global Modeling and Assimilation Office. The adoption of SMAP data into these systems via data assimilation techniques will not be without difficulty and will require rigorous testing to ensure that the SMAP data in used in such a way that improves forecast and prediction capability.

Entin, J. K.

2008-05-01

172

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

173

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

174

Biological activities of lavender essential oil.  

PubMed

Essential oils distilled from members of the genus Lavandula have been used both cosmetically and therapeutically for centuries with the most commonly used species being L. angustifolia, L. latifolia, L. stoechas and L. x intermedia. Although there is considerable anecdotal information about the biological activity of these oils much of this has not been substantiated by scientific or clinical evidence. Among the claims made for lavender oil are that is it antibacterial, antifungal, carminative (smooth muscle relaxing), sedative, antidepressive and effective for burns and insect bites. In this review we detail the current state of knowledge about the effect of lavender oils on psychological and physiological parameters and its use as an antimicrobial agent. Although the data are still inconclusive and often controversial, there does seem to be both scientific and clinical data that support the traditional uses of lavender. However, methodological and oil identification problems have severely hampered the evaluation of the therapeutic significance of much of the research on Lavandula spp. These issues need to be resolved before we have a true picture of the biological activities of lavender essential oil. PMID:12112282

Cavanagh, H M A; Wilkinson, J M

2002-06-01

175

Correlation between biological and physical availabilities of phenanthrene in soils and soil humin in aging experiments  

Microsoft Academic Search

The bioavailability of an organic compound in a soil or sediment commonly declines with the soil-chemical contact time (aging). A series of parallel desorption and bioavailability experiments was carried out on phenanthrene previously aged up to â¼100 d in Mount Pleasant silt loam (Mt. Pleasant, NY, USA) or Pahokee peat soil to determine as a function of the aging period

J. C. White; M. Hunter; K. Nam; J. J. Pignatello; M. Alexander

1999-01-01

176

Effects of cadium, zinc and lead on soil enzyme activities  

Microsoft Academic Search

Heavy metal (HM) is a major hazard to the soil-plant system. This study investigated the combined effects of cadium (Cd), zinc (Zn) and lead (Pb) on activities of four enzymes in soil, including calatase, urease, invertase and alkalin phosphatase. HM content in tops of canola and four enzymes activities in soil were analyzed at two months after the metal additions

Zhi-xin YANG; Shu-qing LIU; Da-wei ZHENG; Sheng-dong FENG

2006-01-01

177

NASA Soil Moisture Active Passive (SMAP) Applications  

NASA Astrophysics Data System (ADS)

The launch of the NASA Soil Moisture Active Passive (SMAP) mission in 2014 will provide global soil moisture and freeze-thaw measurements at moderate resolution (9 km) with latency as short as 24 hours. The resolution, latency and global coverage of SMAP products will enable new applications in the fields of weather, climate, drought, flood, agricultural production, human health and national security. To prepare for launch, the SMAP mission has engaged more than 25 Early Adopters. Early Adopters are users who have a need for SMAP-like soil moisture or freeze-thaw data, and who agreed to apply their own resources to demonstrate the utility of SMAP data for their particular system or model. In turn, the SMAP mission agreed to provide Early Adopters with simulated SMAP data products and pre-launch calibration and validation data from SMAP field campaigns, modeling, and synergistic studies. The applied research underway by Early Adopters has provided fundamental knowledge of how SMAP data products can be scaled and integrated into users' policy, business and management activities to improve decision-making efforts. This presentation will cover SMAP applications including weather and climate forecasting, vehicle mobility estimation, quantification of greenhouse gas emissions, management of urban potable water supply, and prediction of crop yield. The presentation will end with a discussion of potential international applications with focus on the ESA/CEOS TIGER Initiative entitled "looking for water in Africa", the United Nations (UN) Convention to Combat Desertification (UNCCD) which carries a specific mandate focused on Africa, the UN Framework Convention on Climate Change (UNFCCC) which lists soil moisture as an Essential Climate Variable (ECV), and the UN Food and Agriculture Organization (FAO) which reported a food and nutrition crisis in the Sahel.

Orr, Barron; Moran, M. Susan; Escobar, Vanessa; Brown, Molly E.

2014-05-01

178

Effects of Zero Tillage (No-Till) Conservation Agriculture on soil physical and biological properties and their contributions to sustainability  

NASA Astrophysics Data System (ADS)

Not cultivating soil, rotating crops over the years, and leaving crop residues on the surface in the practice of zero tillage/conservation agriculture (ZT/CA) reverses the historically accelerating degradation of soil organic matter (SOM) and soil structure, while increasing soil biological activity by a factor of 2 to 4. The results of this are many: (a) not cultivating reduces soil compaction, leaving old root holes to facilitate internal drainage, averts the pulverization of soil aggregates and formation of pans, reduces draft power for planting and gives shelter, winter food and nesting sites for fauna, (b) crop residues on the surface practically eliminate wind and water erosion, reduce soil moisture loss through the mulch effect, slow spring warm-up (possibly offset by a lower specific heat demand with less water retention in surface soil) and act as a reserve of organically-compounded nutrients (as they decompose to humus), (c) more SOM means higher available water and nutrient retention, higher biological activity year round (enhancing biological controls), higher levels of water-stable aggregates and a positive carbon sink in incremental SOM. The positive impacts for society are: (i) more and cheaper food, (ii) reduced flood and drought-induced famine risks, (iii) a positive carbon sink in SOM and possible reductions in NO2 emissions, (iv) cleaner water and greater aquifer recharge due to reduced runoff, (v) cleaner air through effective elimination of dust as a product of cultivation (vi) less water pollution and greater aquifer recharge from reduced rainfall runoff, (vii) farm diesel consumption halved, (viii) reduced demand for (tropical) de-forestation, by permitting crop expansion on steeper lands, (ix) increased wildlife populations (skylarks, plovers, partridge and peccaries) and (x) an improved conservation mindset in farmers. It is notable that, in spite of successful practitioners in all European countries, mainstream adoption is still to come: Europés ZT/CA area is 1.35 million hectares, while the world area is now some 125 million and growing at a rate of 7 million hectares per year. More scientific measurements of the benefits of this system are required, both to assist adoption and to trigger policy measures. In the EEC, CAP reform (greening) needs to consider making environmental services payments for these social benefits since a reduction in single farm payments is ineluctable and carbon footprint reduction is of the essence, in the face of constantly-rising fuel prices and the need to cut GHG emissions. Therefore, as the principal farm tool which offers an effective and immediate solution towards positive changes in soil quality, productivity and sustainability, ZT/CA adoption needs financial incentives, which have high economic and environmental returns to society.

Landers, John N.; Rass, Gerard; de Freitas, Pedro L.; Basch, Gottlieb; González Sanchez, Emilio J.; Tabaglio, Vincenzo; Kassan, Amir; Derpsch, Rolf; Friedrich, Theodor; Giupponi, Luca

2013-04-01

179

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.

2013-01-01

180

Changes of soil organic matter and microbial activity in irrigated and non irrigated olive groves  

NASA Astrophysics Data System (ADS)

The implementation of olive cultivation techniques in Greece has not been systematically tested under the prevailing Mediterranean conditions. A LIFE+ project was initiated (oLIVE-CLIMA; LIFE 11/ENV/000942) aiming to introduce new management practices in olive tree crops that lead to increased carbon dioxide uptake by plants as well as carbon sequestration from the atmosphere and reverse the trend of soil organic matter decline, erosion and desertification. This paper presents data on soil organic matter and microbial activity from a soil campaign in a pilot region in Greece, and particularly in the area of Chora, prefecture of Messinia, South west Peloponnese. The soil campaign took place during the period December 2012-February 2013. Twelve soil parcels of olive groves were selected (6 irrigated and 6 rainfed) and in each soil parcel six composite soil samples were taken from 0-10 cm depth at equal intervals along a straight line of the trunk of the tree to the middle of the distance from the nearest tree of the next tree series. The first three samples were under olive tree canopy. An additional composite sample was taken at depth of 10-40 cm. Soil samples were analyzed for soil physicochemical and biological properties. In this study results for total organic carbon (TOC), soil basal microbial respiration (BR), microbial biomass C (MB-C) from the region of Messinia, are presented. Organic matter was determined by dichromate oxidation. The microbial activity was measured by the amount of CO2 evolution, while microbial biomass C was determined by substrate-induced respiration, after the addition of glucose. The results showed considerable differences in TOC, BR and MB-C associated with the sampling position and soil depth. The higher TOC, BR and MB-C values, in most cases, were determined in samples taken from points under the canopy, but not close to the tree trunk compared to the sampling points outside the canopy. This indicates the positive effect of rhizosphere and the favorable soil moisture conditions under tree canopy on soil microbial activities. TOC, BR and MB-C values were considerably lower in soil depth of 10-40cm compared with 0-10 cm in both irrigated and rainfed soil parcels. Moreover BR and MB-C was higher in irrigated soil parcels compared with rainfed ones suggesting that the periodic irrigation significantly enhances the soil microbial activity. There were no considerable differences in TOC. For this the TOC and potential activity of microbial community can contribute in the soil nutrient and irrigation management guidelines in order to exploit the utilization of productive soils in the region under studied.

Kavvadias, Victor; Papadopoulou, Maria; Theocharopoulos, Sideris; Vavoulidou, Evagelia; Doula, Maria; Reppas, Spiros

2014-05-01

181

Biological activities of Bv8 analogues  

PubMed Central

The small protein Bv8, secreted by the skin of the frog Bombina variegata, belongs to a novel family of secreted proteins whose orthologues have been identified in snakes (MIT) and in mammals (prokineticins (PKs)). A characteristic feature of this protein family is the same N-terminal sequence, AVITGA, and the presence of 10 cysteines with identical spacing in the C-terminal domain. Two closely related G protein-coupled receptors that mediate signal transduction of Bv8/PKs have been cloned (PK-R1 and PK-R2). In mammals, the Bv8/PK protein family is involved in a number of biological activities such as ingestive behaviours, circadian rhythms, angiogenesis and pain sensitization. In an attempt to identify the structural determinants required for the pronociceptive activity of Bv8, we prepared Bv8 derivatives lacking one (des-Ala-Bv8) or two (des-Ala-Val-Bv8) residues from the N-terminus. des-Ala-Bv8 displayed a receptor affinity five times lower than that of Bv8, it was five times less potent in inducing [Ca2+]i transients and in causing p42/p44 MAPK phosphorylation in CHO-cells expressing PK-R1 and PK-R2. Moreover, dA-Bv8 was about 20 times less potent than Bv8 in inducing hyperalgesia in rats. The deletion of the first two amino acids of Bv8 abolished any biological activity both ‘in vitro' and ‘in vivo'; however, des-AlaVal-Bv8 is able to antagonize the Bv8-induced hyperalgesia, binding the PK-Rs on peripheral and central projections of the primary sensitive neurons.

Negri, Lucia; Lattanzi, Roberta; Giannini, Elisa; Colucci, Maria Antonella; Mignogna, Giuseppina; Barra, Donatella; Grohovaz, Fabio; Codazzi, Franca; Kaiser, Alessandra; Kreil, Guenther; Melchiorri, Pietro

2005-01-01

182

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

183

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

184

Effects of tanneries wastewater on chemical and biological soil characteristics  

Microsoft Academic Search

Effluents from leather processing, a major industry that produces up to 64320t wastewater year?1 in the town of León (Guanajuato, Mexico), are normally discharged to the river Turbio without treatment. This water is downstream used to irrigate agricultural land. Tannery wastewater contains valuable nutrients, but also contaminants, such as salts and chromium (Cr), that might affect soil processes and crop

D. Alvarez-Bernal; S. M. Contreras-Ramos; N. Trujillo-Tapia; V. Olalde-Portugal; J. T. Frías-Hernández; L. Dendooven

2006-01-01

185

Rescuing biological activity from synthetic phakellistatin 19.  

PubMed

Phakellistatins is one of the families of Pro-rich cyclic peptides whose synthetic counterparts have revealed cytotoxicities that differ greatly from those displayed by their corresponding natural ones. This is also the case of the last member isolated from this family, phakellistatin19, an octacyclopeptide containing three Pro moieties and a high percentage of apolar residues. Exhaustive NMR studies on the synthetic and natural phakellistatin 19 have been performed in order to find a plausible explanation for this intriguing behavior. Moreover, taking advantage of phakellistatin's framework, analogues with different cis/trans geometry at the key prolyl peptide bonds were designed, covering a promising conformational space that could not be reached by the natural peptide. By introduction of proline surrogates (?(Me,Me)pro residues) in phakellistatin 19, which effectively increases the percentage of cis conformation in the final peptides, this translates into enhanced biological activity, therefore "rescuing" an otherwise inactive cyclopeptide. PMID:24252114

Pelay-Gimeno, Marta; Meli, Alessandra; Tulla-Puche, Judit; Albericio, Fernando

2013-12-12

186

Biological activity of some conjugated gibberellins  

Microsoft Academic Search

The biological activity of several gibberellin (GA) conjugates was studied and compared with that of the corresponding free GAs. The following conjugates were included: O(3)-ß-d-glucopyranosides of GA1, GA3 and GA4; O(13)-ß-d-glucopyranosides of GA1, GA3 and GA5; O(13)-ß-d-glucopyranosyl-GA5-ß-d-glucopyranosyl ester; GA3-ß-d-glucopyranosyl ester and GA3-a-d-glucopyranosyl ester; N-GA3-oyl-glycine, its methyl ester, N-GA3-oyl-glycylglycine, and N-GA3-oyl-proline. All compounds were synthesized chemically but some of them are

G. Sembdner; E. Borgmann; G. Schneider; H. W. Liebisch; O. Miersch; G. Adam; M. Lischewski; K. Schrefber

1976-01-01

187

Biological Soil Crusts of the Subalpine, Alpine, and Nival Areas in the Alps  

Microsoft Academic Search

\\u000a In the Alps, a relatively large amount of landscape occurs in the subalpine, alpine, and nival zones. In these zones, orographic\\u000a and climatic conditions result in many areas with poorly-developed vascular vegetation. Abundant biological soil communities\\u000a colonize the gaps between the plants. The most outstanding soil-crust development is found in windswept places of the alpine\\u000a and nival zones, and on

R. Türk; G. Gärtner

188

Spatial modeling of biological soil crusts to support rangeland assessment and monitoring  

USGS Publications Warehouse

Biological soil crusts are a diverse soil surface community, prevalent in semiarid regions, which function as ecosystem engineers and perform numerous important ecosystem services. Loss of crusts has been implicated as a factor leading to accelerated soil erosion and other forms of land degradation. To support assessment and monitoring efforts aimed at ensuring the sustainability of rangeland ecosystems, managers require spatially explicit information concerning potential cover and composition of biological soil crusts. We sampled low disturbance sites in Grand Staircase-Escalante National Monument (Utah, USA) to determine the feasibility of modeling the potential cover and composition of biological soil crusts in a large area. We used classification and regression trees to model cover of four crust types (light cyanobacterial, dark cyanobacterial, moss, lichen) and 1 cyanobacterial biomass proxy (chlorophyll a), based upon a parsimonious set of GIS (Geographic Information Systems) data layers (soil types, precipitation, and elevation). Soil type was consistently the best predictor, although elevation and precipitation were both invoked in the various models. Predicted and observed values for the dark cyanobacterial, moss, and lichen models corresponded moderately well (R 2 = 0.49, 0.64, 0.55, respectively). Cover of late successional crust elements (moss + lichen + dark cyanobacterial) was also successfully modeled (R2 = 0.64). We were less successful with models of light cyanobacterial cover (R2 = 0.22) and chlorophyll a (R2 = 0.09). We believe that our difficulty modeling chlorophyll a concentration is related to a severe drought and subsequent cyanobacterial mortality during the course of the study. These models provide the necessary reference conditions to facilitate the comparison between the actual cover and composition of biological soil crusts at a given site and their potential cover and composition condition so that sites in poor condition can be identified and management actions can be taken.

Bowker, M. A.; Belnap, J.; Miller, M. E.

2006-01-01

189

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

190

Watering, fertilization, and slurry inoculation promote recovery of biological crust function in degraded soils.  

PubMed

Biological soil crusts are very sensitive to human-induced disturbances and are in a degraded state in many areas throughout their range. Given their importance in the functioning of arid and semiarid ecosystems, restoring these crusts may contribute to the recovery of ecosystem functionality in degraded areas. We conducted a factorial microcosm experiment to evaluate the effects of inoculation type (discrete fragments vs slurry), fertilization (control vs addition of composted sewage sludge), and watering frequency (two vs five times per week) on the cyanobacterial composition, nitrogen fixation, chlorophyll content, and net CO2 exchange rate of biological soil crusts inoculated on a semiarid degraded soil from SE Spain. Six months after the inoculation, the highest rates of nitrogen fixation and chlorophyll a content were found when the biological crusts were inoculated as slurry, composted sewage sludge was added, and the microcosms were watered five times per week. Net CO2 exchange rate increased when biological crusts were inoculated as slurry and the microcosms were watered five times per week. Denaturing gradient gel electrophoresis fingerprints and phylogenetic analyses indicated that most of the cyanobacterial species already present in the inoculated crust had the capability to spread and colonize the surface of the surrounding soil. These analyses showed that cyanobacterial communities were less diverse when the microcosms were watered five times per week, and that watering frequency (followed in importance by the addition of composted sewage sludge and inoculation type) was the treatment that most strongly influenced their composition. Our results suggest that the inoculation of biological soil crusts in the form of slurry combined with the addition of composted sewage sludge could be a suitable technique to accelerate the recovery of the composition and functioning of biological soil crusts in drylands. PMID:16710791

Maestre, Fernando T; Martín, Noelia; Díez, Beatriz; López-Poma, Rosario; Santos, Fernando; Luque, Ignacio; Cortina, Jordi

2006-10-01

191

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

Microsoft Academic Search

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

A. R. Moldenke; N. Baumeister; B. A. Caldwell; R. Griffith; E. R. Ingham; J. Wernz; M. G. Johnson; P. T. Rygiewicz; D. T. Tingey

1994-01-01

192

Biological soil crusts exhibit a dynamic response to seasonal rain and release from grazing with implications for soil stability  

USGS Publications Warehouse

In Northern Mexico, long-term grazing has substantially degraded semiarid landscapes. In semiarid systems, ecological and hydrological processes are strongly coupled by patchy plant distribution and biological soil crust (BSC) cover in plant-free interspaces. In this study, we asked: 1) how responsive are BSC cover/composition to a drying/wetting cycle and two-year grazing removal, and 2) what are the implications for soil erosion? We characterized BSC morphotypes and their influence on soil stability under grazed/non-grazed conditions during a dry and wet season. Light- and dark-colored cyanobacteria were dominant at the plant tussock and community level. Cover changes in these two groups differed after a rainy season and in response to grazing removal. Lichens with continuous thalli were more vulnerable to grazing than those with semi-continuous/discontinuous thalli after the dry season. Microsites around tussocks facilitated BSC colonization compared to interspaces. Lichen and cyanobacteria morphotypes differentially enhanced resistance to soil erosion; consequently, surface soil stability depends on the spatial distribution of BSC morphotypes, suggesting soil stability may be as dynamic as changes in the type of BSC cover. Longer-term spatially detailed studies are necessary to elicit spatiotemporal dynamics of BSC communities and their functional role in biotically and abiotically variable environments. ?? 2009 Elsevier Ltd.

Jimenez, Aguilar, A.; Huber-Sannwald, E.; Belnap, J.; Smart, D. R.; Arredondo, Moreno, J. T.

2009-01-01

193

Plant invasion of native grassland on serpentine soils has no major effects upon selected physical and biological properties  

Microsoft Academic Search

Plant invasions alter soil microbial community composition; this study examined whether invasion-induced changes in the soil microbial community were reflected in soil aggregation, an ecosystem property strongly influenced by microorganisms. Soil aggregation is regulated by many biological factors including roots, arbuscular mycorrhizal fungal hyphae, and microbially-derived carbon compounds. We measured root biomass, fungal-derived glomalin-related soil protein (GRSP), and aggregate mean

Katharine M. Batten; Johan Six; Kate M. Scow; Matthias C. Rillig

2005-01-01

194

Succession of N cycling processes in biological soil crusts on a Central European inland dune.  

PubMed

Biological soil crusts (BSCs) are microbial assemblages that occur worldwide and facilitate ecosystem development by nitrogen (N) and carbon accumulation. N turnover within BSC ecosystems has been intensively studied in the past; however, shifts in the N cycle during BSC development have not been previously investigated. Our aim was to characterise N cycle development first by the abundance of the corresponding functional genes (in brackets) and second by potential enzyme activities; we focussed on the four processes: N fixation (nifH), mineralisation as proteolysis and chitinolysis (chiA), nitrification (amoA) and denitrification (nosZ). We sampled from four phases of BSC development and from a reference located in the rooting zone of Corynephorus canescens, on an inland dune in Germany. BSC development was associated with increasing amounts of chlorophyll, organic carbon and N. Potential activities increased and were highest in developed BSCs. Similarly, the abundance of functional genes increased. We propose and discuss three stages of N process succession. First, the heterotrophic stage (mobile sand without BSCs) is dominated by mineralisation activity. Second, during the transition stage (initial BSCs), N accumulates, and potential nitrification and denitrification activity increases. Third, the developed stage (established BSCs and reference) is characterised by the dominance of nitrification. PMID:22816620

Brankatschk, Robert; Fischer, Thomas; Veste, Maik; Zeyer, Josef

2013-01-01

195

The influence of added organic matter on soil physical, chemical, and biological properties: a small-scale and short-time experiment using straw  

Microsoft Academic Search

Organic matter plays an important and multi-faceted role in soil. Physically, organic matter influences soil structure and all associated properties. Chemically, soil organic matter affects the cation exchange capacity and the capacity for buffering changes in soil pH. Biologically, organic matter acts as the nutrient and energy supply for microbial biomass and higher plants. A soil which is biologically and

Eilín Walsh; Kevin P. McDonnell

2012-01-01

196

Sorption of quaternary ammonium compounds in soils: implications to the soil microbial activities.  

PubMed

Despite their widespread use in household activities and various industries, information on the toxicity of quaternary ammonium compounds (QACs) to microbial activities in soil is scant. This study investigated the effect of three commonly used QACs namely hexadecyltrimethyl ammonium bromide (HDTMA), octadecyltrimethyl ammonium bromide (ODTMA) and Arquad on dehydrogenase and potential nitrification activities in three different soils. The toxicity of QACs on the dehydrogenase activity and potential nitrification in these soils followed the order: HDTMA>ODTMA>Arquad and Arquad>HDTMA>ODTMA, respectively. HDTMA, ODTMA and Arquad exhibited toxicity to dehydrogenase activity at concentration of 50, 100 and 750 mg kg(-1) soil, respectively, whereas potential nitrification was inhibited by HDTMA and ODTMA even at 50 mg kg(-1) soil. Arquad exhibited toxicity to potential nitrification at comparatively higher concentration of 250 mg kg(-1) soil, with the severity of toxicity very intense at higher concentrations. The nature of QACs and soil properties influenced the toxicity. The toxic effect of QACs on soil microbial activities was more influenced by the relative release of sorbed QACs in soils. This study provides valuable information on the toxicological properties of some widely used QACs on important soil microbial activity parameters. To our knowledge, this is the first report. PMID:20855157

Sarkar, Binoy; Megharaj, Mallavarapu; Xi, Yunfei; Krishnamurti, G S R; Naidu, Ravi

2010-12-15

197

Nonexercise activity thermogenesis (NEAT): environment and biology.  

PubMed

Nonexercise activity thermogenesis (NEAT) is the energy expended for everything that is not sleeping, eating, or sports-like exercise. It includes the energy expended walking to work, typing, performing yard work, undertaking agricultural tasks, and fidgeting. NEAT can be measured by one of two approaches. The first is to measure or estimate total NEAT. Here, total daily energy expenditure is measured, and from it "basal metabolic rate-plus-thermic effect of food" is subtracted. The second is the factoral approach, whereby the components of NEAT are quantified, and total NEAT is calculated by summing these components. The amount of NEAT that humans perform represents the product of the amount and types of physical activities and the thermogenic cost of each activity. The factors that impact a human's NEAT are readily divisible into environmental factors, such as occupation or dwelling within a "concrete jungle," and biological factors such as weight, gender, and body composition. The combined impact of these factors explains the substantial variance in human NEAT. The variability in NEAT might be viewed as random, but human and animal data contradict this. It appears that changes in NEAT subtly accompany experimentally induced changes in energy balance and are important in the physiology of weight change. Inadequate modulation of NEAT plus a sedentary lifestyle may thus be important in obesity. It then becomes intriguing to dissect mechanistic studies that delineate how NEAT is regulated into neural, peripheral, and humoral factors. A scheme is described in this review in which NEAT corresponds to a carefully regulated "tank" of physical activity that is crucial for weight control. PMID:15102614

Levine, James A

2004-05-01

198

Sorption of quaternary ammonium compounds in soils: Implications to the soil microbial activities  

Microsoft Academic Search

Despite their widespread use in household activities and various industries, information on the toxicity of quaternary ammonium compounds (QACs) to microbial activities in soil is scant. This study investigated the effect of three commonly used QACs namely hexadecyltrimethyl ammonium bromide (HDTMA), octadecyltrimethyl ammonium bromide (ODTMA) and Arquad on dehydrogenase and potential nitrification activities in three different soils. The toxicity of

Binoy Sarkar; Mallavarapu Megharaj; Yunfei Xi; G. S. R. Krishnamurti; Ravi Naidu

2010-01-01

199

Effects of lead pollution on different soil enzyme activities  

Microsoft Academic Search

We studied the effects of Pb pollution on soil dehydrogenase and phosphatase activity. Samples of four soils (Saxe, Podestà, Porto Teulada, and Sa Xia Manna) were collected from various locations in southwestern Sardinia, Italy. The soils, which differ mainly in heavy metal contents of pedologic origin (Cu, Zn, Cd, and Pb), were treated with Pb (0, 100, 500, 1000, and

C. Marzadori; C. Ciavatta; D. Montecchio; C. Gessa

1996-01-01

200

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

201

Natural phenanthrenes and their biological activity.  

PubMed

The aim of this review is to survey the various naturally occurring phenanthrene compounds that have been isolated from different plants. Only one review has previously been published on this topic. Gorham (1989) reviewed the structures, biosynthesis, separations and spectroscopy of stilbenes and phenanthrenes. The present study furnishes an overview of the hydroxy or/and methoxy-substituted 9,10-dihydro/phenanthrenes, methylated, prenylated and other monomeric derivatives, dimeric and trimeric phenanthrenes and their biological activities. A fairly large number of phenanthrenes have been reported from higher plants, mainly in the Orchidaceae family, in the species Dendrobium, Bulbophyllum, Eria, Maxillaria, Bletilla, Coelogyna, Cymbidium, Ephemerantha and Epidendrum. A few phenanthrenes have been found in the Hepaticae class and Dioscoreaceae, Combretaceae and Betulaceae families. Their distribution correlates strongly with the taxonomic divisions. These plants have often been used in traditional medicine, and phenanthrenes have therefore been studied for their cytotoxicity, antimicrobial, spasmolytic, anti-inflammatory, antiplatelet aggregation, antiallergic activities and phytotoxicity. On the basis of 120 references, this review covers the phytochemistry and pharmacology of phenanthrenes, describing 252 compounds. This contribution stems from our work on the medicinal plant Tamus communis. PMID:18243254

Kovács, Adriána; Vasas, Andrea; Hohmann, Judit

2008-03-01

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

Influence of soil physicochemical and biological properties on the degradation and adsorption of the nematicide fosthiazate.  

PubMed

The degradation and adsorption of the organophosphorus nematicide fosthiazate were investigated in nine soils with various physicochemical and biological characteristics. Fosthiazate was more persistent in acidic soils (pH <6), with half-life (t1/2) values ranging from 53.3 to 57.7 days, compared to soils with higher pH (pH >7), with t1/2 ranging from 14.1 to 20.7 days. Application of antibacterial and antifungal antibiotics to soil samples resulted in a significant inhibition of fosthiazate degradation only in two of the three acidic soils. In contrast, soil autoclaving resulted in doubling the t1/2 of fosthiazate in all studied soils, suggesting that both microbial and abiotic processes contribute to fosthiazate degradation. Statistical analysis indicated a significant negative correlation (P < 0.01) between soil pH and t1/2. Fosthiazate was generally weakly adsorbed with Freundlich adsorption coefficient (Kf) values ranging from 1.23 to 2.74 mL/g. Fosthiazate concentration was strongly correlated with soil organic matter content with higher Kf values in soils with higher organic matter content (P < 0.01). The mean t1/2 and Kf values derived from the laboratory studies were used to parametrize the FOCUS groundwater (GW) models PRZM, PELMO, PEARL, and MACRO for nematicide application in potato and tomato crops. Predicted environmental concentrations produced by the models PEARL and MACRO suggested a potential risk for GW in several scenarios, unlike PELMO and PRZM, which predicted low risk for GW. These findings suggest that the environmental fate of fosthiazate is strongly influenced by soil characteristics and that this nematicide should be used with care in acidic, light soils with low organic matter content. PMID:16939340

Pantelelis, Ioannis; Karpouzas, Dimitrios G; Menkissoglu-Spiroudi, Urania; Tsiropoulos, Nikolas

2006-09-01

204

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

205

Effects of biological soil crusts on surface roughness and implications for runoff and erosion  

NASA Astrophysics Data System (ADS)

Soil surface roughness has a strong influence on runoff and erosion, affecting surface storage capacity, water flow routing and velocity, and modifying runoff rates. It also reduces soil detachment by raindrops and the shear effect of water flow on the soil surface. In arid and semiarid ecosystems, biological soil crusts (BSCs) commonly appear in clearings between plants. Depending on the dominant component in the BSC community, the roughness of the soil surface may vary considerably, changing the hydrologic and erosive response of the soil. The aim of this study is to determine the effect of physical and biological crusts on soil surface roughness and their influence on runoff and erosion. For this purpose, we set up open plots containing different BSC types and treatments and recorded runoff and total erosion from all the events for 18 months. Micro-topographic indexes were calculated from high-resolution digital surface models of the plots built from terrestrial laser scanner height data. After comparing different spatial resolutions and indexes, we concluded that only the local Random Roughness index in a 40-mm moving window provided a precise estimation of the roughness induced by BSCs, though it did not have a direct effect on runoff response. The best relationship between microtopography and runoff on biologically crusted soils was found for surface storage capacity, which appears as a powerful predictor of the runoff coefficient on long temporal scales. Sediment yield was not well predicted by any of the micro-topographic indexes studied. The only index that was significantly related to sediment yield was the local Random Roughness in a 40 mm moving window, but even this explained only a third of the erosion variance.

Rodríguez-Caballero, Emilio; Cantón, Yolanda; Chamizo, Sonia; Afana, Ashraf; Solé-Benet, Albert

2012-04-01

206

Geophysical Monitoring of Microbial Activity within a Wetland Soil  

NASA Astrophysics Data System (ADS)

We performed Induced Polarization (IP) and Self Potential (SP) measurements to record the geoelectrical signatures of microbial activity within a wetland soil. The experiment was conducted in laboratory, utilizing an open flow column set up. Soil samples from Kearny Marsh (KM), a shallow water wetland, were collected and stored at 4o Celsius prior to the start of the experiment. Two columns were dry packed with a mix of KM soil and sterile Ottawa sand (50% by weight). One column was sterilized and used as a control while the other column retained the biologically active soil sample. Both columns were saturated with a minimal salts medium capable of supporting microbial life; after saturation, a steady flow rate of one pore volume per day was maintained throughout the experiment. Ambient temperature and pressure changes (at the inflow and outflow of each column) were continuously monitored throughout the experiment. Common geochemical parameters, such as Eh, pH, and fluid conductivity were measured at the inflow and outflow of each column at regular intervals. IP and SP responses were continuously recorded on both columns utilizing a series of electrodes along the column length; additionally for the SP measurements we used a reference electrode at the inflow tube. Strong SP anomalies were observed for all the locations along the active column. Black visible mineral precipitant also formed in the active column. The observed precipitation coincided with the times that SP anomalies developed at each electrode position. These responses are associated with microbial induced sulfide mineralization. We interpret the SP signal as the result of redox processes associated with this mineralization driven by gradients in ionic concentration and mobility within the column, similar to a galvanic cell mechanism. IP measurements show no correlation with these visual and SP responses. Destructive analysis of the samples followed the termination of the experiment. Scanning electron microscopy (SEM) and Energy Dispersive Spectrometry (EDS) were used to identify and quantify the presence and composition of the mineral precipitation in the control and active columns. Further geochemical measurements are currently being performed in order to confirm and more accurately quantify the mineralization and associated processes.

O'Brien, M.; Zhang, C.; Ntarlagiannis, D.; Slater, L.; Yee, N.

2007-05-01

207

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

208

Effects of Biological Soil Crust on Desert Insect Diversity: Evidence from the Tengger Desert of Northern China  

Microsoft Academic Search

Biological soil crusts are widespread in arid and semiarid regions. They are one of the major components of desert ecosystems, and their importance has been demonstrated by numerous researchers. However, little research has been carried out on the relationship between biological soil crusts and the diversity of desert insects. In this study, psammophilous Caragana korshinskii-Artemisia ordosica communities occurring on semifixed

X. R. Li; Y. W. Chen; Y. G. Su; H. J. Tan

2006-01-01

209

Office of Biological Informatics and Outreach geospatial technology activities  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) Office of Biological Informatics and Outreach (OBIO) in Reston, Virginia, and its Center for Biological Informatics (CBI) in Denver, Colorado, provide leadership in the development and use of geospatial technologies to advance the Nation's biological science activities.

U.S. Geological Survey

1998-01-01

210

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...

211

Watering, Fertilization, and Slurry Inoculation Promote Recovery of Biological Crust Function in Degraded Soils  

Microsoft Academic Search

Biological soil crusts are very sensitive to human-induced disturbances and are in a degraded state in many areas throughout their range. Given their importance in the functioning of arid and semiarid ecosystems, restoring these crusts may contribute to the recovery of ecosystem functionality in degraded areas. We conducted a factorial microcosm experiment to evaluate the effects of inoculation type (discrete

Fernando T. Maestre; Noelia Martín; Beatriz Díez; Rosario López-Poma; Fernando Santos; Ignacio Luque; Jordi Cortina

2006-01-01

212

Biological Degradation of Black Carbon in Temperate Forest Soils: Effects of Clay Mineralogy and Nitrogen Availability  

NASA Astrophysics Data System (ADS)

A critical knowledge gap in soil organic carbon (SOC) cycling concerns the SOC portion collectively known as pyrogenic C or black carbon (BC), which is a chemically heterogeneous class of highly reduced compounds produced by incomplete combustion. While the stocks of BC are significant in surface soils worldwide, this SOC pool has been considered to be relatively inert with negligible biologically mediated degradation of BC occurring. We will present findings from a laboratory incubation of dual-labeled (13C/15N) BC and its precursor wood (Pinus ponderosa) in two temperate soils (Haploxeralfs) that differ in their clay mineralogy (granitic versus andesitic parent material) and organic C content. In addition, we used N additions in the granitic soil to investigate the effects of N availability on soil and substrate C and N cycling. Sterile controls were used to demonstrate that the BC turnover observed was biotic. The laboratory incubations were carried out at 25°C and at 55% of soil water holding capacity. We are measuring the flux of mineralized 13C in respired CO2, dissolved organic C, soil microbial biomass, specific microbial groups (13C-phospholipid fatty acids) and density-defined soil organic matter fractions. The overall flux of 15N is being observed in the microbial biomass, soluble organic and inorganic pools, and organic matter fractions. We will present rates of biologically-mediated decomposition of BC and its precursor wood, as well as the effects of soil mineralogy and N availability on these rates and on products of decomposition. We will also present decomposition rates of native SOM in incubations with and without substrate to investigate C priming.

Bird, J. A.; Santos, F.; Torn, M. S.

2008-12-01

213

Wildfire-resistant biological soil crusts and fire-induced loss of soil stability in Palouse prairies, USA  

USGS Publications Warehouse

Frequent low-intensity fires are a natural component of the ecology of the Palouse prairies of northwestern North America. To study the effects of fire upon biological soil crusts (BSCs) occurring in these grasslands, we sampled three burned (in 2000) sites and three unburned sites in the Hell's Canyon area (OR, USA) ???1 year post-fire. We measured vascular plant and BSC cover, soil microbe pigmentation, texture and chemistry, and soil surface physical properties (stability and rugosity). Festuca idahoensis was two times more abundant in unburned plots (P=0.0006), and vascular plant and litter cover were generally higher in unburned plots. At the community scale, there was no difference in the lichen and moss species composition, suggesting much less drastic effects of fire on BSCs than reported in other systems. Soil surface stability (measured using slake value) was significantly lower in burned sites than unburned sites (median value=5 versus 6, P=0.008), a result which is likely due to the greater density of lichens and mosses encountered in the unburned plots. Soil microbe pigmentation was lower in burned plots (P=0.03), suggesting that the biomass of photosynthetic microbes had decreased; however, the presence of intra- and extracellular pigments in burned soils indicates that microorganisms were not eradicated. Pigments most strongly associated with cyanobacteria were more abundant in unburned sites, suggesting that cyanobacteria may have been more strongly impacted by the fire than other BSC components. Composition of nutrients and surface rugosity did not differ significantly between treatments. We hypothesize that Palouse prairie soil crusts are relatively resistant to wildfire because of low fire intensity and their occupation of space away from the vascular plant fuel load.

Bowker, M. A.; Belnap, J.; Rosentreter, R.; Graham, B.

2004-01-01

214

The effects of heavy metal pollution on enzyme activities and basal soil respiration of roadside soils  

Microsoft Academic Search

In this study, soil samples (0–5 cm depth) were taken from ten different roadside fields of intensive traffic regions of Van-Turkey\\u000a in order to determine the effects of heavy metal pollution on enzymes and microbial activities of soils. Basal soil respiration\\u000a (BSR), arylsulphatase (ASA), alkaline phosphatase (APA) and urease (UA) enzyme activities, and heavy metal contents (Pb, Cr,\\u000a Ni, Cd, Fe,

Füsun Gülser; Esin Erdo?an

2008-01-01

215

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

216

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.

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

2009-01-01

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

Influence of metal oxide particles on soil enzyme activity and bioaccumulation of two plants.  

PubMed

Particle size and metal species are important to both soil microbial toxicity and phytotoxicity in the soil ecosystem. The effects of CuO and ZnO nanoparticles (NPs) and microparticles (MPs) on soil microbial toxicity, phytotoxicity, and bioaccumulation in two crops (Cucumis sativus and Zea mays) were estimated in a soil microcosm. In the microcosm system, soil was artificially contaminated with 1,000 mg/kg CuO and ZnO NPs and MPs. After 15 days, we compared the microbial toxicity and phytotoxicity by particle size. In addition, C. sativus and Z. mays were cultivated in soils treated with CuO NPs and ZnO NPs, after which the treatment effects on bioaccumulation were evaluated. NPs were more toxic than MPs to microbes and plants in the soil ecosystem. We found that the soil enzyme activity and plant biomass were inhibited to the greatest extent by CuO NPs. However, in a Biolog test, substrate utilization patterns were more dependent upon metal type than particle size. Another finding indicated that the metal NP uptake amounts of plants depend on the plant species. In the comparison between C. sativus and Z. mays, the accumulation of Cu and Zn by C. sativus was noticeably higher. These findings show that metal oxide NPs may negatively impact soil bacteria and plants. In addition, the accumulation patterns of NPs depend on the plant species. PMID:23751560

Kim, Sunghyun; Sin, Hyunjoo; Lee, Sooyeon; Lee, Insook

2013-09-28

219

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

220

Radon flux density and radon soil volume activity seasonal variations associated with the soils freezing  

NASA Astrophysics Data System (ADS)

Measurements of radon soil volume activity and radon flux density from the soil surface is carried out while monitoring the stress-strain state of geological environment in order to forecast earthquakes as well as for ecological studies. It is known that these quantities may have significant seasonal fluctuations associated with the soil surface layer freezing. This process complicates the interpretation of experimental data. A mathematical model of radon transport in freezing soil surface layer is described in this paper. It is assumed that the frozen layer of soil is permeable to radon, but it has a lower diffusion coefficient. The thickness of the frozen layer increases with time and reaches a maximum value as the blanket of snow is fixed. The volume activity increase factor at a depth of 0.7 m and surface radon flux decrease factor during soil freezing are calculated. The calculation was performed for the values of the maximum depth of soil freezing from 0 to 1 m and for the values of the soil radon diffusion length from 0.5 to 2 m. The calculation revealed that the freezing of the upper layer of soil radon volume activity at a depth of 0.7 m on average increases in 1.7 times, and the flux density of radon from the soil surface decreases by an average of 1.8 times. The results of the 3-month of the radon soil volume activity at depths of 0.7 and 2.7 m and ground temperature at depths of 0.01, 0.21, 0.31, 0.51, 1, 2, 3 m monitoring at a research testing area Yekaterinburg is obtained. The theoretical results are well agreed with experimental data. The results obtained in this paper can be used when interpreting the values of volume activity of radon in soil air and the flux density of radon from the soil surface, measured in the cold season.

Klimshin, A.

2011-12-01

221

Effect of rotation breaks and organic matter amendments on the capacity of soils to develop biological suppression towards soil organisms associated with yield decline of sugarcane  

Microsoft Academic Search

A plant bioassay was developed to test the capacity of soil to suppress the activity of detrimental soil organisms associated with yield decline (YD) of sugarcane. The bioassay utilised the diseased roots of sugarcane plants growing in soil that had been under continuous sugarcane monoculture for more than 20 years, as the source of soil organisms associated with YD. Single-eye

C. E. Pankhurst; B. L. Blair; R. C. Magarey; G. R. Stirling; M. J. Bell; A. L. Garside

2005-01-01

222

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.

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

2011-01-01

223

Lung biological activity of American attapulgite  

SciTech Connect

Attapulgite is a fibrous mineral industrially consumed at the rate of over a million tons per year but the biological activity of the material is not fully known. To evaluate the in vivo toxicity of the fibrous materials, they exposed the tracheal lobe of 16 sheep to a single exposure of either 100 ml saline, 100 mg UICC asbestos fibers in 100 ml saline, 100 mg short asbestos fibers in 100 ml saline, or 100 mg attapulgite in 100 ml saline. The animals were studied by bronchoalveolar lavage (BAL) at Days 2, 12, 24, 40, and 60 and by autopsy at Day 60. In the saline-exposed sheep, BAL and lung histology did not change. In the UICC asbestos-exposed animals, they reproduced the BAL changes previously reported. In the short asbestos-exposed sheep, there were no significant BAL changes. In the attapulgite sheep, they found significant and sustained increases in total BAL cells, macrophages, neutrophils, fibronectin, lactate dehydrogenase, ..beta..-glucuronidase, but BAL cellularity returned to control levels by Day 60 whereas in the UICC asbestos-exposed sheep, it remained significantly above control. Lung histology demonstrated the characteristic peribronchiolar fibrosing alveolitis in the UICC asbestos-exposed sheep, whereas macrophagic alveolitis with minimal airway distortion was seen in the short asbestos-exposed sheep, whereas macrophagic alveolitis with minimal airway distortion was seen in the short asbestos-exposed sheep and in all of the attapulgite-exposed sheep but three which had typical peribronchiolar alveolitis quite similar to that observed in UICC-exposed sheep, but of lower intensity.

Begin, R.; Masse, S.; Rola-Pleszczynski, M.; Geoffroy, M.; Martel, M.; Desmarais, Y.; Sebastien, P.

1987-04-01

224

Daily dynamics of cellulase activity in arable soils depending on management practices  

Microsoft Academic Search

The daily dynamics of cellulase activity was studied during 27 days by the cellophane membrane method on soils managed using\\u000a the conventional high-input farming system (application of mineral fertilizers and pesticides) and the biological conservation\\u000a farming system (application of organic fertilizers alone) in a microfield experiment. The regular oscillatory dynamics of\\u000a the cellulase activity were revealed and confirmed by the

E. V. Lavrent’eva; A. M. Semenov; V. V. Zelenev; Yu. Chzhun; E. V. Semenova; V. M. Semenov; B. B. Namsaraev; A. H. C. Van Bruggen

2009-01-01

225

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

226

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

227

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

228

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.

Brulikova, Lucie

2011-01-01

229

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...

230

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.

Maestre, Fernando T.; Bowker, Matthew A.; Escolar, Cristina; Puche, Maria D.; Soliveres, Santiago; Maltez-Mouro, Sara; Garcia-Palacios, Pablo; Castillo-Monroy, Andrea P.; Martinez, Isabel; Escudero, Adrian

2010-01-01

231

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

PubMed

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

2010-07-12

232

Microbial Community Structure and Enzyme Activities in Semiarid Agricultural Soils  

NASA Astrophysics Data System (ADS)

The effect of agricultural management practices on the microbial community structure and enzyme activities of semiarid soils of different textures in the Southern High Plains of Texas were investigated. The soils (sandy clay loam, fine sandy loam and loam) were under continuous cotton (Gossypium hirsutum L.) or in rotations with peanut (Arachis hypogaea L.), sorghum (Sorghum bicolor L.) or wheat (Triticum aestivum L.), and had different water management (irrigated or dryland) and tillage (conservation or conventional). Microbial community structure was investigated using fatty acid methyl ester (FAME) analysis by gas chromatography and enzyme activities, involved in C, N, P and S cycling of soils, were measured (mg product released per kg soil per h). The activities of b-glucosidase, b-glucosaminidase, alkaline phosphatase, and arylsulfatase were significantly (P<0.05) increased in soils under cotton rotated with sorghum or wheat, and due to conservation tillage in comparison to continuous cotton under conventional tillage. Principal component analysis showed FAME profiles of these soils separated distinctly along PC1 (20 %) and PC2 (13 %) due to their differences in soil texture and management. No significant differences were detected in FAME profiles due to management practices for the same soils in this sampling period. Enzyme activities provide early indications of the benefits in microbial populations and activities and soil organic matter under crop rotations and conservation tillage in comparison to the typical practices in semiarid regions of continuous cotton and conventional tillage.

Acosta-Martinez, V. A.; Zobeck, T. M.; Gill, T. E.; Kennedy, A. C.

2002-12-01

233

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

234

Assimilation of Passive and Active Microwave Soil Moisture Retrievals  

NASA Technical Reports Server (NTRS)

Root-zone soil moisture is an important control over the partition of land surface energy and moisture, and the assimilation of remotely sensed near-surface soil moisture has been shown to improve model profile soil moisture [1]. To date, efforts to assimilate remotely sensed near-surface soil moisture at large scales have focused on soil moisture derived from the passive microwave Advanced Microwave Scanning Radiometer (AMSR-E) and the active Advanced Scatterometer (ASCAT; together with its predecessor on the European Remote Sensing satellites (ERS. The assimilation of passive and active microwave soil moisture observations has not yet been directly compared, and so this study compares the impact of assimilating ASCAT and AMSR-E soil moisture data, both separately and together. Since the soil moisture retrieval skill from active and passive microwave data is thought to differ according to surface characteristics [2], the impact of each assimilation on the model soil moisture skill is assessed according to land cover type, by comparison to in situ soil moisture observations.

Draper, C. S.; Reichle, R. H.; DeLannoy, G. J. M.; Liu, Q.

2012-01-01

235

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

Microsoft Academic Search

\\u000a Due to a wide range of industrial and agricultural activities, a high number of chemical contaminants is released into the\\u000a environment, causing a significant concern regarding potential toxicity, carcinogenicity, and potential for bioaccumulation\\u000a in living systems of various chemicals in soil. Although microbial activity in soil accounts for most of the degradation of\\u000a organic contaminants, chemical and physical mechanisms can

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

236

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

237

Correlation between biological and physical availabilities of phenanthrene in soils and soil humin in aging experiments  

SciTech Connect

The bioavailability of an organic compound in a soil or sediment commonly declines with the soil-chemical contact time (aging). A series of parallel desorption and bioavailability experiments was carried out on phenanthrene previously aged up to {approximately}100 d in Mount Pleasant silt loam (Mt. Pleasant, NY, USA) or Pahokee peat soil to determine as a function of the aging period the degree of correlation between the reduction in bioavailability and the rate and extent of desorption and the influence of soil organic matter composition on availability. The mineralization of phenanthrene by two bacteria and the uptake of phenanthrene by earthworms showed expected declines with aging. Likewise, the rate of phenanthrene desorption in the absence of organisms decreased with aging. The decline in initial rate of mineralization or desorption was nearly an order of magnitude after 50 to 60 d of aging. Plots of normalized rates of mineralization or desorption practically coincided. Similarly, plots of normalized fraction mineralized or fraction desorbed during an arbitrary period gave comparable slopes. The partial removal of organic matter from the peat by extraction with dilute NaOH to leave the humin fraction reduced the biodegradation of phenanthrene aged for 38 and 63 d as compared to the nonextracted peat, but the effect disappeared at longer incubation times. The rate of desorption from samples of peat previously extracted with NaOH or Na{sub 4}P{sub 2}O{sub 7} declined with aging and, for a given aging period, was significantly slower than from nonextracted peat. This work shows that the reduction in bioavailability of phenanthrene over time in soil is directly correlated with reduction of its physical availability due to desorption limitations. In addition, this study shows that removal of extractable humic substances leads to a decline in the rate of desorption and in the bioavailability of the substrate.

White, J.C.; Hunter, M.; Nam, K.; Pignatello, J.J.; Alexander, M.

1999-08-01

238

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

239

Biological nitrogen fixation by lucerne (Medicago sativa L.) in acid soils  

Microsoft Academic Search

Growth of lucerne<\\/TT>( Medicago sativa L.) is poor in soils with values of pH-H2O below 6. This is often due to nitrogen deficiency, resulting from a hampered performance of the symbiosis with<\\/TT>Rhizobium meliloti. This thesis deals with the factors affecting biological nitrogen fixation by lucerne in acid soils.<\\/TT>In a field experiment, lucerne seeds were either inoculated with<\\/TT>R.meliloti only,or inoculated and

J. W. M. Pijnenborg

1990-01-01

240

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

241

Soil climate and decomposer activity in Sub-Saharan Africa estimated from standard weather station data: a simple climate index for soil carbon balance calculations.  

PubMed

Soil biological activity was calculated on a daily basis, using standard meteorological data from African weather stations, a simple soil water model, and commonly used assumptions regarding the relations between temperature, soil water content, and biological activity. The activity factor r(e_clim) is calculated from daily soil moisture and temperature, thereby taking the daily interaction between temperature and moisture into account. Annual mean r(e_clim) was normalized to 1 in Central Sweden (clay loam soil, no crop), where the original calibration took place. Since soils vary in water storage capacity and plant cover will affect transpiration, we used this soil under no crop for all sites, thereby only including climate differences. The Swedish r(e_clim) value, 1, corresponds to ca. 50% annual mass loss of, e.g., cereal straw incorporated into the topsoil. African mean annual r(e_clim) values varied between 1.1 at a hot and dry site (Faya, Chad) and 4.7 at a warm and moist site (Brazzaville, Congo). Sites in Kenya ranged between r(e_clim) = 2.1 at high altitude (Matanya) and 4.1 in western Kenya (Ahero). This means that 4.1 times the Swedish C input to soil is necessary to maintain Swedish soil carbon levels in Ahero, if soil type and management are equal. Diagrams showing daily r(e_clim) dynamics are presented for all sites, and differences in within-year dynamics are discussed. A model experiment indicated that a Swedish soil in balance with respect to soil carbon would lose 41% of its soil carbon during 30 y, if moved to Ahero, Kenya. If the soil was in balance in Ahero with respect to soil carbon, and then moved to Sweden, soil carbon mass would increase by 64% in 30 y. The validity of the methodology and results is discussed, and r(e_clim) is compared with other climate indices. A simple method to produce a rough estimate of r(e_clim) is suggested. PMID:17847802

Andrén, Olof; Kihara, Job; Bationo, André; Vanlauwe, Bernard; Kätterer, Thomas

2007-07-01

242

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.

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

2008-01-01

243

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

244

Hydrolytic enzyme activities in agricultural and forest soils. Some implications for their use as indicators of soil quality  

Microsoft Academic Search

Although a great deal of information exists about the effect of land use on soil enzyme activities, much of this is contradictory and brings into question the suitability of soil enzyme activities as indicators of how land use affects soil quality. The purpose of this study was to investigate the effect of land use on different soil biochemical properties, especially

C. Trasar-Cepeda; M. C. Leirós; F. Gil-Sotres

2008-01-01

245

Active and passive organic matter fractions in Mediterranean forest soils  

Microsoft Academic Search

Soil organic carbon (C) is a complex set of pools, and to understand its dynamics it is necessary to know which of these pools\\u000a are active at a given moment, and which act as passive, due to either physical protection or biochemical recalcitrance, or\\u000a both. This matter has been studied mainly in agricultural soils. For forest soils, especially in Mediterranean

Pere Rovira; Montserrat Jorba; Joan Romanyà

2010-01-01

246

The elmiric acids: Biologically active anandamide analogs  

Microsoft Academic Search

As chemical entities, lipoamino acids have been known for some time. However, more recently their occurrence and importance in mammalian species has been discovered. They appear to have close relationships with the endocannabinoids not only structurally but also in terms of biological actions. The latter include analgesia, anti-inflammatory effects, inhibition of cell proliferation and calcium ion mobilization. To date about

Sumner Burstein

2008-01-01

247

Soil enzyme activities and organic matter composition in a turfgrass chronosequence  

Microsoft Academic Search

Highly managed turfgrass systems accumulate considerable soil organic C, which supports a diverse and robust soil microbial community. Degradation of this soil organic C is mediated by a suite of soil enzymes. The relationship between these enzyme activities and the quality of soil organic C is central to understanding the dynamics of soil organic matter. We examined the activities of

Wei Shi; Emily Dell; Daniel Bowman; Kannan Iyyemperumal

2006-01-01

248

Microbial Diversity and Structure Are Drivers of the Biological Barrier Effect against Listeria monocytogenes in Soil  

PubMed Central

Understanding the ecology of pathogenic organisms is important in order to monitor their transmission in the environment and the related health hazards. We investigated the relationship between soil microbial diversity and the barrier effect against Listeria monocytogenes invasion. By using a dilution-to-extinction approach, we analysed the consequence of eroding microbial diversity on L. monocytogenes population dynamics under standardised conditions of abiotic parameters and microbial abundance in soil microcosms. We demonstrated that highly diverse soil microbial communities act as a biological barrier against L. monocytogenes invasion and that phylogenetic composition of the community also has to be considered. This suggests that erosion of diversity may have damaging effects regarding circulation of pathogenic microorganisms in the environment.

Vivant, Anne-Laure; Garmyn, Dominique; Maron, Pierre-Alain; Nowak, Virginie; Piveteau, Pascal

2013-01-01

249

Phorbol Esters: Structure, Biological Activity, and Toxicity in Animals  

Microsoft Academic Search

Phorbol esters are the tetracyclic diterpenoids generally known for their tumor promoting activity. The phorbol esters mimic the action of diacyl glycerol (DAG), activator of protein kinase C, which regulates different signal transduction pathways and other cellular metabolic activities. They occur naturally in many plants of the family Euphorbiacaeae and Thymelaeaceae. The biological activities of the phorbol esters are highly

Gunjan Goel; Harinder P. S. Makkar; George Francis; Klaus Becker

2007-01-01

250

Activated Sludge. Student Manual. Biological Treatment Process Control.  

ERIC Educational Resources Information Center

This student manual contains the textual material for a seven-lesson unit on activated sludge. Topic areas addressed in the lessons include: (1) activated sludge concepts and components (including aeration tanks, aeration systems, clarifiers, and sludge pumping systems); (2) activated sludge variations and modes; (3) biological nature of activated

Boe, Owen K.; Klopping, Paul H.

251

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

252

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

253

Use of organic amendments as a bioremediation strategy to reduce the bioavailability of chlorpyrifos insecticide in soils. Effects on soil biology.  

PubMed

The sorption capacity of both an organic municipal solid waste by-product (MSW) and a cow manure (CM) in a soil polluted with chlorpyrifos, as well as its effect on soil microbial activity, and weight, reproductive parameters and glutathione-S-transferase activity of two earthworm species (Eisenia fetida and Lumbricus terrestris) were studied. Chlorpyrifos was added at the recommended application rate (5 L ha(-1); 768 mg chlorpyrifos kg(-1)) and treated with MSW at a rate of 10% and CM at a rate of 5.8% in order to apply the same amount of organic matter to the soil. An unamended polluted soil was used as control. Earthworm cocoon number, average weight of cocoon, and number of juveniles per cocoon were measured after 30 days of incubation, whereas soil enzymatic activities, earthworm weight, and glutathione-S-transferase activity of earthworms were measured after 3, 45 and 90 days. Soil enzymatic activities, reproductive and glutathione-S-transferase activity in both worms decreased in polluted soil. The inhibition percentage of soil enzymatic activities, reproductive and glutathione-S-transferase activity in both worms was lower in MSW-amended soil than for CM-amended soil. The toxic effect of chlorpyrifos on E. fetida was lowest compared to L. terrestris. This suggested that the addition of organic wastes with higher humic than fulvic acid concentration is more beneficial for remediation of soils polluted with chlorpyrifos. PMID:21813178

Tejada, Manuel; Gómez, Isidoro; Del Toro, Marina

2011-10-01

254

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

255

Preparing for NASA's Soil Moisture Active Passive (SMAP) Mission  

Microsoft Academic Search

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

T. Jackson; D. Entekhabi; E. Njoku; P. O'Neill; J. Entin

2009-01-01

256

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

257

Prediction of Biological Activity Spectra via The Internet  

Microsoft Academic Search

The majority of biologically active compounds have both pharmacotherapeutic and side\\/toxic actions. To estimate general efficacy and safety of the molecules under study, their biological potential should be thoroughly evaluated. In an early stage of study, only information about structural formulae was available and was used as an input for computational prediction. Based on a structural formulae of compounds presented

A. Sadym; A. Lagunin; D. Filimonov; V. Poroikov

2003-01-01

258

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

259

Recovery of soil base saturation following termination of N deposition: Increased biological weathering?  

NASA Astrophysics Data System (ADS)

Current models suggest the removal rate of base cations (i.e. calcium, magnesium, potassium, and sodium) from forest soils due to forest growth or forest management practices is greater than the resupply rate in many areas of North America and Europe. This is particularly concerning given the recent historical depletion of base cations from forest soils during times of high acid deposition and their critical role in buffering against acidity changes in both soils and surface waters. Because base cations are not easily replaced in soil, being primarily supplied through slow processes such as the primary weathering of parent minerals or the decomposition of organic materials, rapid removals of base cations can jeopardize the long-term fertility of forests. Using a long-term nitrogen (N) addition experiment in a Pinus sylvestris forest that has been ongoing since 1970, we examined how the availability of inorganic N mediates the recovery of base cations in forest soil and tree pools in a boreal forest in northern Sweden. Contrary to model projections, exchangeable base cations in the top 10 cm of mineral soils recovered much faster than predicted. The base saturation of mineral soils in the high N addition treatment (90 kg N ha-1), which was applied annually from 1970-1990 and has been allowed to recover for the last 22 years, was 120% of that of soil in the control treatment. Similarly, the base saturation of the upper 10 cm of mineral soil in the medium N treatment (60 kg N ha-1 yr-1) increased from 30% of that of the control in 2007 following 37 years of N addition to 80% of that of the control in 2010 following two years of recovery. Importantly, the base saturation of the low N treatment (30 kg N ha-1 yr-1) continually declined from 1970 to 2007 and remained low in 2010. Furthermore, the total calcium pool in the top 10 cm of mineral soil was significantly lower in the high and medium N treatments than in the control treatment. These results suggest there may have been an increase in the weathering rate of base cations following the termination of N addition. Such an increase may be biologically mediated by the soil microbial community receiving increased allocation of recent photosynthate below ground following the termination of N addition and is not accounted for in current biogeochemical models.

Lucas, R. W.; Högberg, P.

2012-12-01

260

Distribution and activity of hypolithic soil crusts in a hyperarid desert (Baja California, Mexico)  

Microsoft Academic Search

Widespread and ecologically important, biological soil crusts include those microbial communities living on the surface of the soil and those that live beneath semitranslucent rocks (a.k.a. hypolithic crusts). We examined the distribution, abundance, physiology, and potential soil N contributions of hypolithic, biological crusts in hyperarid ecosystems of the Baja California peninsula and islands in the midriff region of the Gulf

Katherine A. Heckman; Wendy B. Anderson; D. Alexander Wait

2006-01-01

261

Biological activity of feijoa peel extracts.  

PubMed

Fractionated extracts of Feijoa peels were studied for cytotoxic activity, anti-human immunodeficiency virus (HIV) activity and antibacterial activity. Two most cytotoxic fractions A3 of acetone extract and M2 of methanol extract had potent inhibitory activity against Gram-positive and Gram-negative bacteria as well as fungi tested. Fraction A4 of acetone extract showed multidrug resistance (MDR)-reversal activity comparable with that of verapamil (positive control). These results indicate the therapeutic value of Feijoa peel extracts as potential antimicrobial and MDR-modulating agents. PMID:11205266

Motohashi, N; Kawase, M; Shirataki, Y; Tani, S; Saito, S; Sakagami, H; Kurihara, T; Nakashima, H; Wolfard, K; Mucsi, I; Varga, A; Molnár, J

2000-01-01

262

Synthesis and biological activity of chloroethyl pyrimidine nucleosides.  

PubMed

The synthesis and biological activity of chloroethyl pyrimidine nucleosides is presented. One of these new nucleosides analogues significantly inhibited cell proliferation, migration and invasion as tested in vitro on the A431 vulvar epidermal carcinoma cell line. PMID:18205066

Colombeau, Ludovic; Teste, Karine; Hadj-Bouazza, Amel; Chaleix, Vincent; Zerrouki, Rachida; Kraemer, Michel; Catherine, Odile Sainte

2008-02-01

263

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

264

Studies of Oligosaccharins: Carbohydrates Possessing Biological Regulatory Activity.  

National Technical Information Service (NTIS)

Oligosaccharins are complex carbohydrates with biological regulatory activity. This report describes the progress made in isolating and characterizing several oligosaccharins. 15 refs., 2 tabs. (ERA citation 12:035798)

A. G. Darvill P. Albersheim

1985-01-01

265

Evaluation of Biological Activated Carbon for Industrial Water Reuse.  

National Technical Information Service (NTIS)

The Biological Activated Carbon (BAC) technology was tested for the production of reusable water, low in organics concentration, from industrial wastewater. Effluent streams from an oil refinery, a pulp mill, a textile dyeing mill, and a fungicide plant w...

M. Schwartz R. G. Rice A. Benedek

1982-01-01

266

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

267

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

268

ACTIVE SOIL DEPRESSURIZATION (ASD) DEMONSTRATION IN A LARGE BUILDING  

EPA Science Inventory

The report gives results of an evaluation of the feasibility of implementing radon resistant construction techniques -- especially active soil depressurization (ASD) -- in new large buildings in Florida. Indoor radon concentrations and radon entry were monitored in a finished bui...

269

Soil Inorganic Carbon in Deserts: Active Carbon Sink or Inert Reservoir?  

NASA Astrophysics Data System (ADS)

Soil inorganic carbon is the third largest C pool in the active global carbon cycle, containing at least 800 petagrams of carbon. Although carbonate dissolution-precipitation reactions have been understood for over a century, the role of soil inorganic carbon in carbon sequestration, and in particular pedogenic carbonate, is a deceptively complex process because it involves interdependent connections among climate, plants, microorganisms, silicate minerals, soil moisture, pH, and Ca supply via rain, dust, or in situ weathering. An understanding of soil inorganic carbon as a sink or reservoir also requires examination of the system at local to continental scales and at seasonal to millennial time scales. In desert soils studied in North America, carbon isotope ratios and radiocarbon dates were measured in combination with electron microscopy, lab and field experiments with biological calcite formation, and field measurements of carbon dioxide emissions. These investigations reveal that soil inorganic carbon is both an active sink and a inert reservoir depending on the spatial and temporal scale and source of calcium.

Monger, H. C.; Cole, D. R.

2011-12-01

270

Biofilm processes in biologically active carbon water purification  

Microsoft Academic Search

This review paper serves to describe the composition and activity of a biologically active carbon (BAC) biofilm used in water purification. An analysis of several physical–chemical, biochemical and microbiological methods (indicators) used to characterize the BAC biofilm's composition and activity is provided. As well, the ability of the biofilm to remove and biodegrade waterborne organic substances and pollutants will be

David R. Simpson

2008-01-01

271

Biological activities of aerial parts of Paeonia emodi Wall  

Microsoft Academic Search

The ethanolic extract derived from the aerial parts of Paeonia emodi was screened for various in vitro biological activities including antifungal, antibacterial, insecticidal, phytotoxic and haemagglutination activities. General toxicity (brine shrimp lethality assay) of this extract has also been assessed. The extract was found to possess excellent phytotoxicity against Lemna minor L., moderate heamagglutination activity against human erythrocytes and reasonable

Taous Khan; Mansoor Ahmad; Hamayun Khan; Mir Azam Khan

272

Effects of biological soil crusts on seed germination of four endangered herbs in a xeric Florida shrubland during drought  

Microsoft Academic Search

Soil crusts of rosemary scrubs in south-central Florida were examined for effects on seed germination of four herbs that are killed by fire and must recruit from seed: Eryngium cuneifolium (Apiaceae), Hypericum cumulicola (Hypericaceae), Polygonella basiramia (Polygonaceae), and Paronychia chartacea ssp. chartacea (Caryophyllaceae). Biological soil crusts in these sites are dominated by algae, cyanobacteria, fungi, and bacteria. Because crusts can

Christine V. Hawkes

2004-01-01

273

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

274

Long-term organic farming fosters below and aboveground biota: Implications for soil quality, biological control and productivity  

Microsoft Academic Search

Organic farming may contribute substantially to future agricultural production worldwide by improving soil quality and pest control, thereby reducing environmental impacts of conventional farming. We investigated in a comprehensive way soil chemical, as well as below and aboveground biological parameters of two organic and two conventional wheat farming systems that primarily differed in fertilization and weed management strategies. Contrast analyses

Klaus Birkhofer; T. Martijn Bezemer; Jaap Bloem; Michael Bonkowski; Søren Christensen; David Dubois; Fleming Ekelund; Andreas Fließbach; Lucie Gunst; Katarina Hedlund; Paul Mäder; Juha Mikola; Christophe Robin; Heikki Setälä; Fabienne Tatin-Froux; Wim H. Van der Putten; Stefan Scheu

2008-01-01

275

Biologically active secondary metabolites from marine cyanobacteria  

PubMed Central

Marine cyanobacteria are a rich source of complex bioactive secondary metabolites which derive from mixed biosynthetic pathways. Recently, several marine cyanobacterial natural products have garnered much attention due to their intriguing structures and exciting anti-proliferative or cancer cell toxic activities. Several other recently discovered secondary metabolites exhibit insightful neurotoxic activities whereas others are showing pronounced anti-inflammatory activity. A number of anti-infective compounds displaying activity against neglected diseases have also been identified, which include viridamides A and B, gallinamide A, dragonamide E, and the almiramides.

Nunnery, Joshawna K.; Mevers, Emily; Gerwick, William H.

2010-01-01

276

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

277

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.

278

Effectiveness of biological geotextiles in reducing runoff and soil loss under different environmental conditions using laboratory and field plot data  

NASA Astrophysics Data System (ADS)

Preliminary investigations suggest biological geotextiles could be an effective and inexpensive soil conservation method, with enormous global potential. Biological geotextiles are a possible temporary alternative for vegetation cover and can offer immediate soil protection. However, limited data are available on the erosion-reducing effects of biological geotextiles. Therefore, the objective of this study is to evaluate the effectiveness of selected types of biological geotextile in reducing runoff and soil loss under controlled laboratory conditions and under field conditions reflecting different environments (i.e. continental, temperate and tropical). In laboratory experiments, interrill runoff, interrill erosion and concentrated flow erosion were simulated using various rainfall intensities, flow shear stresses and slope gradients. Field plot data on the effects of biological geotextiles on sheet and rill erosion were collected in several countries under natural rainfall (U.K., Hungary, Lithuania, South Africa, Brazil, China and Thailand). The laboratory experiments indicate that all tested biological geotextiles were effective in reducing interrill runoff (on average 59% of the value for bare soil) and interrill erosion rates (on average 16% of the value for bare soil). Since simulated concentrated flow discharge sometimes flowed below the geotextiles, the effectiveness in reducing concentrated flow erosion was significantly less (on average 59% of the value for bare soil). On field plots, where both interrill and rill erosion occur, all tested geotextiles reduced runoff depth by a mean of 54% of the control value for bare soil and in some cases, runoff depth increased compared to bare soil surfaces, which can be attributed to the impermeable and hydrophobic characteristics of some biological geotextiles. In the field, soil loss rates due to interrill and rill erosion were reduced by a mean of 21% of the value of bare soil by biological geotextiles. This study demonstrates that data from controlled interrill experiments in the laboratory correspond well to those obtained from field plots. Hence, interrill experiments in the laboratory allow one to predict the hydrological and erosion response of geotextiles on larger field plots. According to the field data, Rice straw geotextiles are the most effective geotextiles in reducing relative runoff and soil loss rates. No impact of plot length on the runoff and soil loss reduction by biological geotextiles was observed.

Smets, T.

2009-04-01

279

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

280

[Galanin: a new biologically active gastrointestinal neuropeptide].  

PubMed

The 29 amino acid containing neuropeptide galanin is localized in the intrinsic nervous system of the entire gastrointestinal tract and the pancreas. It was found in man and several animal species. Molecular biology studies revealed different molecular forms of galanin in several mammalian species including man. The galanin precursor was also found. Galanin shows several potent pharmacological actions: it inhibits gastrointestinal motility in man. It also has an inhibitory effect on intestinal smooth muscle contractility of several animal species. These actions are mediated directly by opening of potassium channels and indirectly by inhibition of acetylcholine release. In addition galanin inhibits pancreatic hormone secretion (i.e. hypoinsulinemia, hyperglycemia) and partly the release of hormones localized in the gastrointestinal tract. On exocrine glands in man (salivary glands) galanin has hydrokinetic actions. The physiological role of galanin might be regulation of gastrointestinal motility, control of secretory function of intestine and a regulatory role in endocrine and exocrine gland secretion. PMID:1693024

Bauer, F E

1990-03-01

281

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

282

Biologically active amphiphilic derivatives of chitosan  

Microsoft Academic Search

Amphiphilic N-derivatives of chitosan containing C12 alkyl and carboxyl groups were obtained. It was shown that the compounds obtained have fungicidal activity and form intermolecular\\u000a associates in solutions.

E. A. Stepnova; V. E. Tikhonov; V. G. Babak; M. A. Krayukhina; K. K. Babievskii; I. A. Yamskov

2005-01-01

283

Differential Nutrient Limitation of Soil Microbial Biomass and Metabolic Quotients (qCO2): Is There a Biological Stoichiometry of Soil Microbes?  

PubMed Central

Background Variation in microbial metabolism poses one of the greatest current uncertainties in models of global carbon cycling, and is particularly poorly understood in soils. Biological Stoichiometry theory describes biochemical mechanisms linking metabolic rates with variation in the elemental composition of cells and organisms, and has been widely observed in animals, plants, and plankton. However, this theory has not been widely tested in microbes, which are considered to have fixed ratios of major elements in soils. Methodology/Principal Findings To determine whether Biological Stoichiometry underlies patterns of soil microbial metabolism, we compiled published data on microbial biomass carbon (C), nitrogen (N), and phosphorus (P) pools in soils spanning the global range of climate, vegetation, and land use types. We compared element ratios in microbial biomass pools to the metabolic quotient qCO2 (respiration per unit biomass), where soil C mineralization was simultaneously measured in controlled incubations. Although microbial C, N, and P stoichiometry appeared to follow somewhat constrained allometric relationships at the global scale, we found significant variation in the C?N?P ratios of soil microbes across land use and habitat types, and size-dependent scaling of microbial C?N and C?P (but not N?P) ratios. Microbial stoichiometry and metabolic quotients were also weakly correlated as suggested by Biological Stoichiometry theory. Importantly, we found that while soil microbial biomass appeared constrained by soil N availability, microbial metabolic rates (qCO2) were most strongly associated with inorganic P availability. Conclusions/Significance Our findings appear consistent with the model of cellular metabolism described by Biological Stoichiometry theory, where biomass is limited by N needed to build proteins, but rates of protein synthesis are limited by the high P demands of ribosomes. Incorporation of these physiological processes may improve models of carbon cycling and understanding of the effects of nutrient availability on soil C turnover across terrestrial and wetland habitats.

Hartman, Wyatt H.; Richardson, Curtis J.

2013-01-01

284

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.

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

2003-01-01

285

Evidence for micronutrient limitation of biological soil crusts: Importance to arid-lands restoration  

USGS Publications Warehouse

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 is most consistent with the hypothesis of causal relationships between the availability of micronutrients and the abundance of the two major nitrogen (N) fixers of BSCs. Specifically, higher Mn availability may determine greater Collema tenax abundance, and both Mn and Zn may limit Collema coccophorum; alternative causal hypotheses were less consistent with the data. We propose experimental trials of micronutrient addition to promote the restoration of BSC function on disturbed lands. Arid lands, where BSCs are most prevalent, cover ???40% of the terrestrial surface of the earth; thus the information gathered in this study is potentially useful in many places worldwide. ?? 2005 by the Ecological Society of America.

Bowker, M. A.; Belnap, J.; Davidson, D. W.; Phillips, S. L.

2005-01-01

286

Combining plant- and soil-dwelling predatory mites to optimise biological control of thrips.  

PubMed

The efficiency of a natural enemy combination compared to a single species release for the control of western flower thrips (WFT) Frankliniella occidentalis (Pergande) on cucumber plants was investigated. Since a large part of F occidentalis seems to enter the soil passage, a joint release of the plant-inhabiting predatory mite Amblyseius cucumeris (Oudemans) that feeds on thrips first-instar larvae and the soil-dwelling predatory mite Hypoaspis aculeifer (Canestrini) that preys on thrips pupae in the ground might offer a promising approach for a holistic control strategy. Therefore, two sets of experiments were conducted in cooperation with a commercial vegetable grower where the plants in plots were infested with a defined number of larval and adult F occidentalis. Two species of natural enemies were released either synchronously or solely, and their efficacy was compared to control plots devoid of antagonists. In both experiments, the predatory mites were released twice with a density of 46 A. cucumeris/m2, and 207 H. aculeifer/m2 (low-density) in the first experiment and 528 H. aculeifer/m2 (high-density) in the second one. Population growth of all arthropod species on the plants and in the soil was quantified at regular intervals and included all soil-dwelling mites and alternative preys present in the substrate. The results showed that H. aculeifer alone had a significant impact on thrips population development only when released at high-densities, but competence was lower compared to the other antagonist treatments. The impact of A. cucumeris alone and A. cucumeris & H. aculeifer combined was similar. Thus, the pooled exploitation of natural enemies did not boost thrips control compared to the single species application of A. cucumeris (non-additive effect), which could be explained by resource competition between both predatory mite species. Species number and population size in the soil of the experimental plots both showed a high variability, a possible consequence of their interaction with released soil-dwelling predatory H. aculeifer mites. The impact of resource competition and presence of alternative preys on thrips biological control is exhaustively discussed. From our study, we can extract the subsequent conclusions: (1) the combined use of H. aculeifer and A. cucumeris cannot increase thrips control on cucumber compared to the release of A. cucumeris alone, but the overall reliability of thrips biological control might be enhanced, (2) the availability of alternative preys seemed to affect the thrips predation rate of H. aculeifer, and (3) the impact of naturally occurring soil predatory mites on the control of WFT seemed to be partial. PMID:15651523

Wiethoff, Jürgen; Poehling, Hans-Michael; Meyhöfer, Rainer

2004-01-01

287

Oxidation by Fenton's reagent combined with biological treatment applied to a creosote-comtaminated soil.  

PubMed

In this study, we investigated the feasibility of using Fenton oxidation to remove sorbed polycyclic aromatic hydrocarbons (PAHs) in aged soil samples with creosote oil from a wood preserving site. The optimal dosage of reagents was determined by a statistical method, the central composite rotatable experimental design. The maximum PAH removal was 80% with a molar ratio of oxidant/catalyst equal to 90:1. In general low molecular weight PAHs (3 rings) were degraded more efficiently than higher molecular weight PAHs (4 and 5 rings). The hydrogen peroxide decomposition kinetic was studied in the presence of KH(2)PO(4) as stabilizer. The kinetic data were fitted to a simple model, the pseudo-first-order which describes the hydrogen peroxide decomposition. The PAH kinetic degradation was also studied, and demonstrated that non-stabilized hydrogen peroxide was consumed in less than 30 min, whilst PAH removal continued for up to 24h. In a second part of the work, a combined chemical and biological treatment of the soil was carried out and shown to be dependent on the pre-oxidation step. Different reagent doses (H(2)O(2):Fe) were used (10, 20, 40, 60:1) in the pre-treatment step. An excess of hydrogen peroxide resulted in a poor biological removal, thus the optimal molar ratio of H(2)O(2):Fe for the combined process was 20:1. The combined treatment resulted in a maximum total PAH removal of 75% with a 30% increase in removal due to the biodegradation step. The sample with highest PAH removal in the pre-oxidation step led to no further increase in removal by biological treatment. This suggests that the more aggressive chemical pre-oxidation does not favour biological treatment. The physico-chemical properties of the pollutants were an important factor in the PAH removal as they influenced chemical, biological and combined treatments. PMID:19135785

Valderrama, C; Alessandri, R; Aunola, T; Cortina, J L; Gamisans, X; Tuhkanen, T

2009-07-30

288

The elmiric acids: biologically active anandamide analogs.  

PubMed

As chemical entities, lipoamino acids have been known for some time. However, more recently their occurrence and importance in mammalian species has been discovered. They appear to have close relationships with the endocannabinoids not only structurally but also in terms of biological actions. The latter include analgesia, anti-inflammatory effects, inhibition of cell proliferation and calcium ion mobilization. To date about 40 naturally occurring members of this family have been identified and, additionally, several synthetic analogs have been prepared and studied. To facilitate their identity, a nomenclature system has been suggested based on the name elmiric acid (EMA). The prototypic example, N-arachidonoyl glycine, does not bind to CB1, however it does inhibit the glycine transporter GLYT2a and also appears to be a ligand for the orphan G-protein-coupled receptor GPR18. It may also have a role in regulating tissue levels of anandamide by virtue of its inhibitory effect on FAAH the enzyme that mediates inactivation of anandamide. Its concentration in rat brain is several-fold higher than anandamide supporting its possible role as a physiological mediator. Future studies should be aimed at elucidating the actions of all of the members of this interesting family of molecules. PMID:18187165

Burstein, Sumner

2008-12-01

289

The elmiric acids: biologically active anandamide analogs  

PubMed Central

Summary As chemical entities, lipoamino acids have been known for some time. However, more recently their occurrence and importance in mammalian species has been discovered. They appear to have close relationships with the endocannabinoids not only structurally but also in terms of biological actions. The latter include analgesia, anti-inflammatory effects, inhibition of cell proliferation and calcium ion mobilization. To date about 40 naturally occurring members of this family have been identified and, additionally, several synthetic analogs have been prepared and studied. To facilitate their identity, a nomenclature system has been suggested based on the name elmiric acid (EMA). The prototypic example, N-arachidonoyl glycine does not bind to CB1, however it does inhibit the glycine transporter GLYT2a and also appears to be a ligand for the orphan G-protein-coupled receptor GPR18. It may also have a role in regulating tissue levels of anandamide by virtue of its inhibitory effect on FAAH the enzyme that mediates inactivation of anandamide. Its concentration in rat brain is several fold higher than anandamide supporting its possible role as a physiological mediator. Future studies should be aimed at elucidating the actions of all of the members of this interesting family of molecules.

Burstein, Sumner

2008-01-01

290

Raman Optical Activity of Biological Molecules  

NASA Astrophysics Data System (ADS)

Now an incisive probe of biomolecular structure, Raman optical activity (ROA) measures a small difference in Raman scattering from chiral molecules in right- and left-circularly polarized light. As ROA spectra measure vibrational optical activity, they contain highly informative band structures sensitive to the secondary and tertiary structures of proteins, nucleic acids, viruses and carbohydrates as well as the absolute configurations of small molecules. In this review we present a survey of recent studies on biomolecular structure and dynamics using ROA and also a discussion of future applications of this powerful new technique in biomedical research.

Blanch, Ewan W.; Barron, Laurence D.

291

Synthesis of biologically active bridged diazabicycloheptanes.  

PubMed

The chemistry underlying how diazabicycloheptanes are assembled is described, subdivided according to chemical structure of two types, the 3,6 diazabicyclo[3.1.1]heptane and the 2,5-diazabicyclo[2.2.1]heptane ring system. Detailed information on myriad of activities of compounds derived from the two scaffolds are reported. PMID:22830336

Murineddu, G; Asproni, B; Pinna, G; Curzu, M M; Dore, A; Pau, A; Deligia, F; Pinna, G A

2012-01-01

292

NEW AMINOPHOSPHONATES - ASSESSMENT OF BIOLOGICAL ACTIVITY  

Microsoft Academic Search

Two series, acyclic and cyclic aminophosphonates were synthesized for potential agrochemical application. They differed inside the series in substituents at the phosphorus, carbon and nitrogen atoms. Their efficiency to destabilize erythrocyte (RBC) and lipid model membranes (BLM), to change plant membrane properties (Nitellopsis obtusa, Beta vulgaris ssp. L. rapacea, Syringa vulgaris L., Cucumis sativus), to change activity of the antioxidative

2009-01-01

293

Effects of Cd and Pb pollution on soil enzymatic activities and soil microbiota  

Microsoft Academic Search

Based on a representative sampling method and pot experiment with different concentrations of Cd and Pd, the enzymatic activities\\u000a (urease, phosphatase, catalase, invertase), population of bacteria, fungus and actinomycete in the soil, the Cd and Pd pollution\\u000a status of soil samples (from the wastewater-irrigated area of Baoding suburb) were appraised. Unitary linear and nonlinear\\u000a curve-fitting optimization models were applied in

Shuqing Liu; Zhixin Yang; Xiaomin Wang; Xiaogui Zhang; Rutai Gao; Xia Liu

2007-01-01

294

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

295

Patterns of diversity for fungal assemblages of biological soil crusts from the southwestern United States.  

PubMed

Molecular methodologies were used to investigate fungal assemblages of biological soil crusts (BSCs) from arid lands in the southwestern United States. Fungal diversity of BSCs was assessed in a broad survey that included the Chihuahuan and Sonoran deserts as well as the Colorado Plateau. At selected sites samples were collected along kilometer-scale transects, and fungal community diversity and composition were assessed based on community rRNA gene fingerprinting using PCR-denaturing gradient gel electrophoresis (DGGE). Individual phylotypes were characterized through band sequencing. The results indicate that a considerable diversity of fungi is present within crusted soils, with higher diversity being recovered from more successionally mature BSCs. The overwhelming majority of crust fungi belong to the Ascomycota, with the Pleosporales being widespread and frequently dominant. Beta diversity patterns of phylotypes putatively representing dominant members of BSC fungal communities suggest that these assemblages are specific to their respective geographic regions of origin. PMID:22123652

Bates, Scott T; Nash, Thomas H; Garcia-Pichel, Ferran

2012-01-01

296

Risk assessment of petroleum-contaminated soil using soil enzyme activities and genotoxicity to Vicia faba.  

PubMed

Pollution caused by petroleum is one of the most serious problems worldwide. To better understand the toxic effects of petroleum-contaminated soil on the microflora and phytocommunity, we conducted a comprehensive field study on toxic effects of petroleum contaminated soil collected from the city of Daqing, an oil producing region of China. Urease, protease, invertase, and dehydrogenase activity were significantly reduced in microflora exposed to contaminated soils compared to the controls, whereas polyphenol oxidase activity was significantly increased (P < 0.05). Soil pH, electrical conductivity, and organic matter content were correlated with total petroleum hydrocarbons (TPHs) and a correlation (P < 0.01) existed between the C/N ratio and TPHs. Protease, invertase and catalase were correlated with TPHs. The Vicia faba micronucleus (MN) test, chromosome aberrant (CA) analyses, and the mitotic index (MI) were used to detect genotoxicity of water extracts of the soil. Petroleum-contaminated samples indicated serious genotoxicity to plants, including decreased index level of MI, increased frequency of MN and CA. The combination of enzyme activities and genotoxicity test via Vicia faba can be used as an important indicator for assessing the impact of TPH on soil ecosystem. PMID:24510466

Ma, Jun; Shen, Jinglong; Liu, Qingxing; Fang, Fang; Cai, Hongsheng; Guo, Changhong

2014-05-01

297

Liposomal packaging generates Wnt protein with in vivo biological activity.  

PubMed

Wnt signals exercise strong cell-biological and regenerative effects of considerable therapeutic value. There are, however, no specific Wnt agonists and no method for in vivo delivery of purified Wnt proteins. Wnts contain lipid adducts that are required for activity and we exploited this lipophilicity by packaging purified Wnt3a protein into lipid vesicles. Rather than being encapsulated, Wnts are tethered to the liposomal surface, where they enhance and sustain Wnt signaling in vitro. Molecules that effectively antagonize soluble Wnt3a protein but are ineffective against the Wnt3a signal presented by a cell in a paracrine or autocrine manner are also unable to block liposomal Wnt3a activity, suggesting that liposomal packaging mimics the biological state of active Wnts. When delivered subcutaneously, Wnt3a liposomes induce hair follicle neogenesis, demonstrating their robust biological activity in a regenerative context. PMID:18698373

Morrell, Nathan T; Leucht, Philipp; Zhao, Ludan; Kim, Jae-Beom; ten Berge, Derk; Ponnusamy, Karthik; Carre, A Lyonel; Dudek, Henryk; Zachlederova, Marie; McElhaney, Michael; Brunton, Shirley; Gunzner, Janet; Callow, Marinella; Polakis, Paul; Costa, Mike; Zhang, Xiaoyan M; Helms, Jill A; Nusse, Roel

2008-01-01

298

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

299

Isolation and biological activity of frankiamide.  

PubMed

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 (HPLC) methods. The novel compound that was isolated, dubbed frankiamide, displayed antimicrobial activity against all 14 Gram-positive bacterial strains and six pathogenic fungal strains tested. The pathogenic actinomycete Clavibacter michiganensis and the oomycete Phytophthora were especially susceptible. In addition to displaying antimicrobial activity, frankiamide also strongly inhibited 45Ca(2+) fluxes in clonal rat pituitary GH4C1 tumor cells and was comparable to a frequently used calcium antagonist, verapamil hydrochloride. The results of HPLC analysis, supported by both nuclear magnetic resonance and mass spectroscopy studies, showed that frankiamide has a high affinity for Na(+) ions. PMID:11598813

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

2001-07-01

300

Biological Activity of Grapevine Phenolic Compounds  

Microsoft Academic Search

Phenolic compounds present in nearly all parts of grape berries are increasingly believed to exhibit antioxidant and antimicrobial\\u000a activities and to play a significant role in the prevention of diseases including cancer and cardiovascular diseases (Bagchi\\u000a et al. 2000, Ariga 2004). The majority of studies on grape phenolics properties has been conducted using proanthocyanidin-rich\\u000a seeds extracts (GSEs).

R. Amarowicz; S. Weidner

301

Cyclic Tritrpticin Analogs with Distinct Biological Activities  

Microsoft Academic Search

Tritrpticin is a Trp-, Arg-, and Pro-rich cathelicidin peptide with promising antimicrobial activity. Cyclic analogs of tritrpticin\\u000a were designed using two different approaches: circularization of the backbone by a head-to-tail peptide bond (TritrpCyc) or\\u000a disulfide bridging between two Cys residues introduced at the termini of the peptide (TritrpDisu). Compared to the parent\\u000a peptide, TritrpCyc has greatly improved therapeutic potential, showing

Leonard T. Nguyen; Johnny K. Chau; Sebastian A. J. Zaat; Hans J. Vogel

2011-01-01

302

Synthesis and biological activity of new arenediyne-linked isoxazolidines.  

PubMed

Arenediyne-isoxazolidine conjugates have been synthesized as a new scaffold for the development of bioactive mimics. Some of the synthesized compounds are endowed with antiproliferative activity against three human cancer cell lines. Their thermal reactivity suggests that the biological activity probably could not be linked to the Bergman cyclization. PMID:24835789

Romeo, Roberto; Navarra, Michele; Giofrè, Salvatore V; Carnovale, Caterina; Cirmi, Santa; Lanza, Giuseppe; Chiacchio, Maria A

2014-07-01

303

Study the Biological Activities of Tribulus Terrestris Extracts  

Microsoft Academic Search

In this study the extracts of the Iraqi herb Tribulus terrestris (Al-Hassage or Al-Kutub) was done by using of polar and non polar solvents, then the biological activity of these extractants was studied in three fields, First, the antibacterial activity (in vitro) on gram positive bacteria (Staphylococcus aureus), and gram negative bacteria (E. coli, Proteus vulgaris, Pseudomonas aerugiuosa, and Klebsiella),

Ahmed A. Hussain; Abbas A. Mohammed; H. Ibrahim; Amir H. Abbas

2009-01-01

304

Molecular and chemical features of the excreted extracellular polysaccharides in Induced Biological Soil Crusts of different ages  

NASA Astrophysics Data System (ADS)

Biological Soil Crusts (BSCs) are complex microbial associations widely distributed in arid and semiarid environments. These microbial associations have recently been acknowledged as important in restoration ecology (Bowker 2007). The primary colonization of cyanobacteria and other crust organisms after events such as fire or cessation of plowing is considered critical for later vascular plant establishment, due to the control of seed germination and due to the complex pathways that BSCs are capable to establish between plants and crust organisms and exudates (Rossi et al. 2013). In a ten year study carried out in the hyper-arid region of Inner Mongolia (China), introduction of man - made BSCs (induced BSCs, IBSCs) proved to be effective in producing a shift of the ecosystem state from high abiotic to low abiotic stress, evidenced by an increase in photothrophic abundance and subshrub cover. The prerequisite for an efficient exploitation of crust organisms as soil colonizers is their capability to secrete large amount of exopolysaccharides (EPS) which are important, among the reasons, as they lead to soil and BSC stabilization and represent a noticeable source of C that can be respired by the crustal community. By these means, a deep chemical and physiological knowledge concerning these exudates is required. Notwithstanding the large amount of literature available, recently thoroughly reviewed by Mager and Thomas (2011), the chemical characteristics of EPS from BSCs, and in particular from IBSCs, have not been investigated yet. We analyzed the monosaccharidic composition and the molecular weight distribution of two EPS fractions, the more soluble fraction and the fraction more tightly bound to cells, extracted from IBSCs collected in the Inner Mongolian desert, inoculated in different years (namely 4, 6 and 8 years before the sampling), thus characterized by different developmental stages. We thereafter investigated the degradation processes involving EPS, assessing the activity of two key enzymes for sugar degradation: dehydrogenase and sucrase. The results obtained demonstrated a high complexity in terms of monosaccharidic composition and molecular weight, the latter resulting differently distributed between the two fractions. Enzymatic activity resulted mainly directed to the more soluble, low - molecular weight carbohydrates. The data presented represent a first study of the biochemical processes involving carbon from EPS released by IBSCs on bare substrates after the colonization of soils by the inoculated cyanobacteria. Bowker MA (2007) Biological soil crusts rehabilitation in theory and practice: an underexploited opportunity. Restoration Ecology 15(1): 13 - 23. Mager DM, Thomas AD (2011) Extracellular polysaccharides from cyanobacterial soil crusts: A review of their role in dryland soil processes. Journal of Arid Environments 75: 91 - 97. Rossi F, Diels L, Olguin E, De Philippis R (2013) Microbial fixation of CO2 in water bodies and in drylands to combat climate change, soil loss and desertification. New Biotechnology. DOI: . http://dx.doi.org/10.1016/j.nbt.2013.12.002.

Rossi, Federico; Lanzhou, Chen; Liu, Yongding; Adessi, Alessandra; De Philippis, Roberto

2014-05-01

305

A versatile system for biological and soil chemical tests on a planetary landing craft. I - Scientific objectives  

NASA Technical Reports Server (NTRS)

We describe an approach for the remote detection and characterization of life in planetary soil samples. A mass spectrometer is used as the central sensor to monitor changes in the gas phase in eleven test cells filled with soil. Many biological assays, ranging from general 'in situ' assays to specific metabolic processes (such as photosynthesis, respiration, denitrification, etc.) can be performed by appropriate additions to the test cell via attached preloaded injector capsules. The system is also compatible with a number of chemical assays such as the analysis of atmospheric composition (both chemical and isotopic), the status of soil water, and the determination of compounds of carbon, nitrogen and sulfur in the soil.

Radmer, R. J.; Kok, B.; Martin, J. P.

1976-01-01

306

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

NASA Technical Reports Server (NTRS)

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 [1]. 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 days. The combined active/passive microwave soil moisture product will have a spatial resolution of 10 km and a mean latency of 24 hours. In addition, the SMAP surface observations will be combined with advanced modeling and data assimilation to provide deeper root zone soil moisture and net ecosystem exchange of carbon. SMAP is expected to launch in the late 2014 - early 2015 time frame.

O'Neill, Peggy; Entekhabi, Dara; Njoku, Eni; Kellogg, Kent

2011-01-01

307

Measurement of microbial biomass and activity in landfill soils  

Microsoft Academic Search

Two complementary techniques, which have been widely used to provide a general measure of microbial biomass or microbial activity in natural soils, were evaluated for their applicability to soils from the Mallard North and Mallard Lake Landfills, DuPage County, Illinois, U.S.A. Included were: (1) a potassium sulphate extraction technique with quantification of organic carbon for measurement of microbial biomass; and

J. E. Bogner; R. M. Miller; K. Spokas

1995-01-01

308

Acid rain and soil microbial activity: effects and their mechanisms  

Microsoft Academic Search

In this investigation, the 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 seedings 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

2009-01-01

309

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

310

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

311

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

312

Earthworm activity in a simulated landfill cover soil shifts the community composition of active methanotrophs.  

PubMed

Landfills represent a major source of methane in the atmosphere. In a previous study, we demonstrated that earthworm activity in landfill cover soil can increase soil methane oxidation capacity. In this study, a simulated landfill cover soil mesocosm (1 m × 0.15 m) was used to observe the influence of earthworms (Eisenia veneta) on the active methanotroph community composition, by analyzing the expression of the pmoA gene, which is responsible for methane oxidation. mRNA-based pmoA microarray analysis revealed that earthworm activity in landfill cover soil stimulated activity of type I methanotrophs (Methylobacter, Methylomonas, Methylosarcina spp.) compared to type II methanotrophs (particularly Methylocystis spp.). These results, along with previous studies of methanotrophs in landfill cover soil, can now be used to plan in situ field studies to integrate earthworm-induced methanotrophy with other landfill management practises in order to maximize soil methane oxidation and reduce methane emissions from landfills. PMID:21925596

Kumaresan, Deepak; Héry, Marina; Bodrossy, Levente; Singer, Andrew C; Stralis-Pavese, Nancy; Thompson, Ian P; Murrell, J Colin

2011-12-01

313

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

314

Modeling in situ soil enzyme activity using continuous field soil moisture and temperature data  

NASA Astrophysics Data System (ADS)

Moisture and temperature are key drivers of soil organic matter decomposition, but there is little consensus on how climate change will affect the degradation of specific soil compounds under field conditions. Soil enzyme activities are a useful metric of soil community microbial function because they are they are the direct agents of decomposition for specific substrates in soil. However, current standard enzyme assays are conducted under optimized conditions in the laboratory and do not accurately reflect in situ enzyme activity, where diffusion and substrate availability may limit reaction rates. The Arrhenius equation, k= A*e(-Ea/RT), can be used to predict enzyme activity (k), collision frequency (A) or activation energy (Ea), but is difficult to parameterize when activities are measured under artificial conditions without diffusion or substrate limitation. We developed a modifed equation to estimate collision frequency and activation energy based on soil moisture to model in-situ enzyme activites. Our model was parameterized using data we collected from the Boston Area Climate Experiment (BACE) in Massachusetts; a multi-factor climate change experiment that provides an opportunity to assess how changes in moisture availability and temperature may impact enzyme activity. Soils were collected from three precipitation treatments and four temperature treatments arranged in a full-factorial design at the BACE site in June 2008, August 2008, January 2009 and June 2009. Enzyme assays were performed at four temperatures (4, 15, 25 and 35°C) to calculate temperature sensitivity and activation energy over the different treatments and seasons. Enzymes activities were measured for six common enzymes involved in carbon (?-glucosidase, cellobiohydrolase, xylosidase), phosphorus (phosphatase) and nitrogen cycling (N-acetyl glucosaminidase, and leucine amino peptidase). Potential enzyme activity was not significantly affected by precipitation, warming or the interaction of the field treatments at any of the dates, however season explained the majority of the variance in enzyme activity for cellobiohydrolase, xylosidase, N-acetyl glucosaminidase and leucine amino peptidase (p<0.01). Changes in seasonal climate appear to have a large effect on enzyme potentials and are likely masking any treatment effects. To model in-situ enzyme activities over the course of a year, daily measurements collected on soil moisture and temperature were used to estimate the collision frequency and activation energy. Our results suggest that collision frequency is largely affected by soil moisture and activation energy affected by soil temperature. Thus, soil enzyme activities are controlled not only by the size of the enzyme pool, but are also strongly affected by temperature and by moisture. Currently, there are no suitable technologies to measure in-situ activities in real-time, but we can make progress in understanding the ecology of enzymes through the combination of lab assays, field sensors, and modeling.

Steinweg, J. M.; Wallenstein, M. D.

2010-12-01

315

Earthworm activity in a simulated landfill cover soil shifts the community composition of active methanotrophs  

Microsoft Academic Search

Landfills represent a major source of methane in the atmosphere. In a previous study, we demonstrated that earthworm activity in landfill cover soil can increase soil methane oxidation capacity. In this study, a simulated landfill cover soil mesocosm (1 m × 0.15 m) was used to observe the influence of earthworms (Eisenia veneta) on the active methanotroph community composition, by analyzing the expression of

Deepak Kumaresan; Marina Héry; Levente Bodrossy; Andrew C. Singer; Nancy Stralis-Pavese; Ian P. Thompson; J. Colin Murrell

316

The Biological and Toxicological Activity of Gases and Vapors  

PubMed Central

A large amount of data on the biological and toxicological activity of gases and vapors has been collected from the literature. Processes include sensory irritation thresholds, the Alarie mouse test, inhalation anesthesia, etc. It is shown that a single equation using only five descriptors (properties of the gases and vapors) plus a set of indicator variables for the given processes can correlate 643 biological and non-lethal toxicological activities of ‘non-reactive’ compounds with a standard deviation of 0.36 log unit. The equation is scaled to sensory irritation thresholds obtained by the procedure of Cometto-Muñiz, and Cain, and provides a general equation for the prediction of sensory irritation thresholds in man. It is suggested that differences in biological/toxicological activity arise primarily from transport from the gas phase to a receptor phase or area, except for odor detection thresholds where interaction with a receptor(s) is important.

Sanchez-Moreno, Ricardo; Gil-Lostes, Javier; Acree, William E.; Cometto-Muniz, J. Enrique; Cain, William S.

2010-01-01

317

Ethnobotany, chemistry, and biological activities of the genus Tithonia (Asteraceae).  

PubMed

The genus Tithonia is an important source of diverse natural products, particularly sesquiterpene lactones, diterpenes, and flavonoids. The collected information in this review attempts to summarize the recent developments in the ethnobotany, biological activities, and secondary metabolite chemistry of this genus. More than 100 structures of natural products from Tithonia are reported in this review. The species that has been most investigated in this genus is T. diversifolia, from which ca. 150 compounds were isolated. Biological studies are described to evaluate the anti-inflammatory, analgesic, antimalarial, antiviral, antidiabetic, antidiarrhoeal, antimicrobial, antispasmodic, vasorelaxant, cancer-chemopreventive, cytotoxic, toxicological, bioinsecticide, and repellent activities. A few of these studies have been carried out with isolated compounds from Tithonia species, but the majority has been conducted with different extracts. The relationship between the biological activity and the toxicity of compounds isolated from the plants of this genus as well as T. diversifolia extracts still remains unclear, and mechanisms of action remain to be determined. PMID:22344901

Chagas-Paula, Daniela A; Oliveira, Rejane B; Rocha, Bruno A; Da Costa, Fernando B

2012-02-01

318

Biological uptake of phosphorus by activated sludge.  

PubMed

The ability of activated sludge to remove phosphates was studied by adding carrier-free (32)P to raw sewage and measuring incorporation of the radioactivity into the cells over a period of time. Radioisotope determinations indicated that 48% of the (32)P radioactivity was removed by 12 hr. However, chemical methods indicated that only 30% of the orthophosphate apparently disappeared from the sewage during this period. Experiments with sludge prelabeled with (32)P indicated that considerable phosphate turnover occurred. The cells released large amounts of radioactivity as they were incorporating fresh phosphates. Starvation in isotonic saline for 18 hr caused the sludge to dump phosphate. When introduced into fresh sewage containing (32)P, the starved sludge removed about 60% of the radioactivity in 6 hr with little phosphate turnover. The ability of sludge to remove (32)P was inhibited approximately 83% by 10(-3)m 2,4-dinitrophenol. This inhibition was at the expense of the cell fraction that contained ribonucleic acid and deoxyribonucleic acid. The sludge cells released orthophosphate when exposed to the chemical agent. Experiments using (45)Ca indicated that calcium phosphate precipitation plays a minor role in phosphate removal under our experimental conditions. PMID:5456935

Yall, I; Boughton, W H; Knudsen, R C; Sinclair, N A

1970-07-01

319

[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

320

Biological Activity of Aminophosphonic Acids and Their Short Peptides  

NASA Astrophysics Data System (ADS)

The biological activity and natural occurrence of the aminophosphonic acids were described half a century ago. Since then the chemistry and biology of this class of compounds have developed into the separate field of phosphorus chemistry. Today it is well acknowledged that these compounds possess a wide variety of promising, and in some cases commercially useful, physiological activities. Thus, they have found applications ranging from agrochemical (with the herbicides glyphosate and bialaphos being the most prominent examples) to medicinal (with the potent antihypertensive fosinopril and antiosteoporetic bisphosphonates being examples).

Lejczak, Barbara; Kafarski, Pawel

321

Temperature sensitivity of microbial respiration, nitrogen mineralization, and potential soil enzyme activities in organic alpine soils  

NASA Astrophysics Data System (ADS)

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 zone were selected, and soils were sampled in three seasons (summer, autumn, and winter). A simple first-order exponential equation was used to calculate constant Q10 values for the C and N mineralization over the investigated temperature range (0-30°C). The Q10 values of the C mineralization (average 2.0) for all study sites were significantly higher than for the N mineralization (average 1.7). The Q10 values of both activities were significantly negatively related to a soil organic matter quality index calculated by the ratios of respiration to the organic soil carbon and mineralized N to the total soil nitrogen. The chemical soil properties or microbial biomass did not affect the Q10 values of C and N mineralization. Moreover, the Q10 values showed no distinct pattern according to sampling date, indicating that the substrate quality and other factors are more important. Using a flexible model function, the analysis of relative temperature sensitivity (RTS) showed that the temperature sensitivity of activities increased with decreasing temperature. The C and N mineralization and potential amino-peptidase activities (tyrosine and leucine) showed an almost constant temperature dependence over 0-30°C. In contrast, ß-glucosidase, ß-xylosidase, and N-acetyl-ß-glucosaminidase showed a distinctive increase in temperature sensitivity with decreasing temperature. Low temperature at the winter sampling date caused a greater increase in the RTS of all microbial activities than for the autumn and summer sampling dates. Our results indicate (1) a disproportion of the RTS for potential enzyme activities of the C and N cycle and (2) a disproportion of the RTS for easily degradable C compounds (ß-glucose, ß-xylose) compared with the C mineralization of soil organic matter. Thus temperature may play an important role in regulating the decay of different soil organic matter fractions due to differences in the relative temperature sensitivities of enzyme activities.

Koch, Oliver; Tscherko, Dagmar; Kandeler, Ellen

2007-12-01

322

Assessment of soil and soil-gas radon activity using active and passive detecting methods in Korea.  

PubMed

Radon ((222)Rn) is a carcinogenic gas produced by the radioactive decay of radium ((226)Ra). It has been reported that soil and soil-gas are primary factors that could cause indoor radon problems. Six sites were selected for this study--Sanbook, Gangcheon, Jikyeong, Choojung, Geumsung and Homyoung--each was classified according to bedrock type. In order to investigate soil-gas radon activities and radon emanating power, innovated active and passive detecting methods were developed and applied under both field and laboratory conditions. Statistical analysis of results confirmed that the radon activity values measured using either active or passive methods under field or laboratory conditions could be interchangeable with each other. PMID:17578670

Je, Hyun-Kuk; Kang, Chi-Gu; Choi, Jae-Young; Lee, Jin-Soo; Chon, Hyo-Taek

2007-08-01

323

Global change and biological soil crusts: Effects of ultraviolet augmentation under altered precipitation regimes and nitrogen additions  

USGS Publications Warehouse

Biological soil crusts (BSCs), a consortium of cyanobacteria, lichens, and mosses, are essential in most dryland ecosystems. As these organisms are relatively immobile and occur on the soil surface, they are exposed to high levels of ultraviolet (UV) radiation and atmospheric nitrogen (N) deposition, rising temperatures, and alterations in precipitation patterns. In this study, we applied treatments to three types of BSCs (early, medium, and late successional) over three time periods (spring, summer, and spring-fall). In the first year, we augmented UV and altered precipitation patterns, and in the second year, we augmented UV and N. In the first year, with average air temperatures, we saw little response to our treatments except quantum yield, which was reduced in dark BSCs during one of three sample times and in Collema BSCs two of three sample times. There was more response to UV augmentation the second year when air temperatures were above average. Declines were seen in 21% of the measured variables, including quantum yield, chlorophyll a, UV-protective pigments, nitrogenase activity, and extracellular polysaccharides. N additions had some negative effects on light and dark BSCs, including the reduction of quantum yield, ??-carotene, nitrogenase activity, scytonemin, and xanthophylls. N addition had no effects on the Collema BSCs. When N was added to samples that had received augmented UV, there were only limited effects relative to samples that received UV without N. These results indicate that the negative effect of UV and altered precipitation on BSCs will be heightened as global temperatures increase, and that as their ability to produce UV-protective pigments is compromised, physiological functioning will be impaired. N deposition will only ameliorate UV impacts in a limited number of cases. Overall, increases in UV will likely lead to lowered productivity and increased mortality in BSCs through time, which, in turn, will reduce their ability to contribute to the stability and fertility of soils in dryland regions. ?? 2008 The Authors Journal compilation ?? 2008 Blackwell Publishing Ltd.

Belnap, J.; Phillips, S. L.; Flint, S.; Money, J.; Caldwell, M.

2008-01-01

324

Generation of biologically active substances in a natural gas flame.  

PubMed Central

Samples of gaseous and solid species taken from the central axis of a 1 megawatt heat-input natural gas flame were tested in vitro for mutagenic activity and teratogenic potential. Mutagenicity was determined by a Salmonella typhimurium forward mutation assay. Potential teratogenicity was indicated by the ability of samples to interfere with the attachment of mammalian cells to a lectin coated surface. Both the mutagenic and anti-attachment activities were found to peak in samples originating from the flame regions where the total polyaromatic compound (PAC) species concentration reached a maximum, indicating a strong correlation between PAC presence in the samples and biological activity. Additional anti-attachment activity was found close to the injection nozzle. No biologically active material was detected beyond the luminous portion of the flame.

Braun, A G; Pakzaban, P; Toqan, M A; Beer, J M

1987-01-01

325

The biological activity of structurally defined inositol glycans  

PubMed Central

Background The inositol glycans (IGs) are glycolipid-derived carbohydrates produced by insulin-sensitive cells in response to insulin treatment. IGs exhibit an array of insulin-like activities including stimulation of lipogenesis, glucose transport and glycogen synthesis, suggesting that they may be involved in insulin signal transduction. However, because the natural IGs are structurally heterogeneous and difficult to purify to homogeneity, an understanding of the relationship between structure and biological activity has relied principally on synthetic IGs of defined structure. Discussion This article briefly describes what is known about the role of IGs in signal transduction and reviews the specific biological activities of the structurally defined IGs synthesized and tested to date. Conclusion A pharmacophore for IG activity begins to emerge from the reviewed data and the structural elements necessary for activity are summarized.

Goel, Meenakshi; Azev, Viatcheslav N; d'Alarcao, Marc

2009-01-01

326

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

327

Soil hydrological and soil property changes resulting from termite activity on agricultural fields in Burkina Faso  

NASA Astrophysics Data System (ADS)

Termites are important ecosystem-engineers in subtropical and tropical regions. The effect of termite activity affecting soil infiltration is well documented in the Sahelian region. Most studies find increased infiltration rates on surfaces that are affected by termite activity in comparison to crusted areas showing non-termite presence. Crusted agricultural fields in the Sanmatenga region in Burkina Faso with clear termite activity were compared to control fields without visual ground dwelling termite activity. Fine scale rainfall simulations were carried out on crusted termite affected and control sites. Furthermore soil moisture change, bulk density, soil organic matter as well as general soil characteristics were studied. The top soils in the study area were strongly crusted (structural crust) after the summer rainfall and harvest of millet. They have a loamy sand texture underlain by a shallow sandy loam Bt horizon. The initial soil moisture conditions were significantly higher on the termite plots when compared to control sites. It was found that the amount of runoff produced on the termite plots was significantly higher, and also the volumetric soil moisture content after the experiments was significantly lower if compared to the control plots. Bulk density showed no difference whereas soil organic matter was significantly higher under termite affected areas, in comparison to the control plots. Lab tests showed no significant difference in hydrophobic behavior of the topsoil and crust material. Micro and macro-structural properties of the topsoil did not differ significantly between the termite sites and the control sites. The texture of the top 5 cm of the soil was also found to be not significantly different. The infiltration results are contradictory to the general literature, which reports increased infiltration rates after prolonged termite activity although mostly under different initial conditions. The number of nest entrances was clearly higher in the termite areas, but apparently did not significantly affect infiltration. The increased soil organic matter contents in the termite affected areas however, are as expected from literature, but did not improve soil aggregation which would be expected given the importance of organic matter in soil aggregation in this type of soils. One of the explanations for the reduced infiltration rates might be that termites bring clay from the finer textured subsoil to the surface to build casts over the organic material on the surface (mainly millet stems). It is speculated that the excavated clay material could be involved in crust formation, only present is in the upper 0.5 cm of the soil crust, which is enough to block pores in the crust surface, hampering infiltration. The topsoil aggregates are slaking under the summer rainfall and the increase in fine textured material, excavated by the termites, could be incorporated into the crust and reduce infiltration. Furthermore this specific effect might also be related to the type of termite involved, as impacts from ecosystem engineers on their environment is highly dependent on the specific species involved.

Mettrop, I.; Cammeraat, L. H.; Verbeeten, E.

2009-04-01

328

[Fungal population structure and its biological effect in rhizosphere soil of continuously cropped potato].  

PubMed

Continuous cropping obstacle is one of the main restriction factors in potato industry. In order to explore the mechanisms of potato's continuous cropping obstacle and to reduce the impact on potato's tuber yield, a field experiment combined with PCR-DGGE molecular fingerprinting was conducted to investigate the fungal population structure and its biological effect in rhizosphere soil of continuously cropped potato. With the increasing year of potato' s continuous cropping, the numbers of visible bands in rhizosphere fungal DGGE profiles increased obviously. As compared with that of CK (rotation cropping), the operational taxonomic unit (OTU) in treatments of one to five years continuous cropping was increased by 38.5%, 38.5%, 30.8%, 46.2%, and 76.9% respectively, indicating that potato's continuous cropping caused an obvious increase in the individual numbers of dominant fungal populations in rhizosphere soil. Also with the increasing year of potato's continuous cropping, the similarity of the fungal population structure among the treatments had a gradual decrease. The sequencing of the fungal DGGE bands showed that with the increasing year of continuous cropping, the numbers of the potato's rhizosphere soil-borne pathogens Fusarium oxysporum and F. solani increased obviously, while the number of Chaetomium globosum, as a biocontrol species, had a marked decrease in the fifth year of continuous cropping. It was suggested that potato' s continuous cropping caused the pathogen fungal populations become the dominant microbial populations in rhizosphere soil, and the rhizosphere micro-ecological environment deteriorated, which in turn affected the root system, making the root vigor and its absorption area reduced, and ultimately, the tuber yield decreased markedly. PMID:23431794

Meng, Pin-Pin; Liu, Xing; Qiu, Hui-Zhen; Zhang, Wen-Ming; Zhang, Chun-Hong; Wang, Di; Zhang, Jun-Lian; Shen, Qi-Rong

2012-11-01

329

Recent studies on the chemistry and biological activities of the organosulfur compounds of garlic (allium sativum)  

Microsoft Academic Search

Garlic, Allium sativum, is known to contain a wide range of biologically active compounds. The organosulfur compounds are mainly the biologically active components of garlic. Many health benefits has been ascribed to them, possessing biological activities including antibacterial, antifungal, antiatherosclerotic, antihypertensive, lipid and cholesterol lowering effects, inhibition of carcinogenesis, enhancing the immune system and other biological activities. The chemistry of

A. Kamel; M. Saleh

2000-01-01

330

Factors affecting invertase activity in soils  

Microsoft Academic Search

Summary The rate of reducing sugars released through invertase activity exhibited a buffer pH optimum of 5.0. Generally, the decline in invertase activity in its pH-profile near the optimal pH range was due to a reversible reaction that involved ionization or deionization of the functional groups in the active centre of the protein, but under highly acidic or alkaline conditions

W. T. FRANKENBERGER Jr; J. B. Johanson

1983-01-01

331

Synthesis and biological activity of mustard derivatives of thymine.  

PubMed

The synthesis and biological activity of a novel DNA cross-linking antitumor agent is presented. The new alkylating agent significantly inhibited cell proliferation, migration and invasion as tested in vitro on the A431 vulvar epidermal carcinoma cell line. PMID:18569783

Hadj-Bouazza, Amel; Teste, Karine; Colombeau, Ludovic; Chaleix, Vincent; Zerrouki, Rachida; Kraemer, Michel; Sainte Catherine, Odile

2008-05-01

332

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

Sevcikova, Zuzana; Pour, Milan; Novak, David; Ulrichova, Jitka; Vacek, Jan

2014-04-01

333

Solar Energy Education. Renewable energy activities for biology  

SciTech Connect

An instructional aid for teachers is presented that will allow biology students the opportunity to learn about renewable energy sources. Some of the school activities include using leaves as collectors of solar energy, solar energy stored in wood, and a fuel value test for green and dry woods. A study of organic wastes as a source of fuel is included. (BCS)

Not Available

1982-01-01

334

On the biological activity of drug molecules: Busulfan and nabumetone  

NASA Astrophysics Data System (ADS)

The electronic structures of drug molecules busulfan (BSU) and nabumetone (NAB) have been investigated by HeI and HeII UV photoelectron spectroscopy (UPS), quantum chemical calculations and virtual docking studies. Their biological activities are discussed in the framework of their electronic and molecular structures, reactivity and drug-enzyme binding.

Novak, Igor; Kova?, Branka

2010-10-01

335

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

336

Pharmacokinetics and biological activity of kinetensin in conscious sheep  

Microsoft Academic Search

Kinetensin is a nonapeptide, originally isolated from pepsin-treated plasma, that shares some sequence homology with the C-teminal end of neurotensin. The present study was designed to determine, by infusing kinetensin to conscious sheep, the pharmacokinetics and a neurotensin-like biological activity (pancreatic polypeptide response) of kinetensin.

D. Read; A. Shulkes; D. Fletcher; K. Hardy

1993-01-01

337

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

338

A Thought on the Biological Activities of Black Tea  

Microsoft Academic Search

Tea is the most widely used ancient beverage in the world and black tea possesses many biological effects on the organisms. It acts as an effective antioxidant because of its free radical-scavenging and metal-chelating ability. Due to this, it is active against inflammation, clastogenesis, and several types of cancer. Tea reduces DNA damage and mutagenesis due to oxidative stress or

Vasundhara Sharma; L. Jagan Mohan Rao

2009-01-01

339

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

340

Modeling Radial Holoblastic Cleavage: A Laboratory Activity for Developmental Biology.  

ERIC Educational Resources Information Center

Introduces a laboratory activity designed for an undergraduate developmental biology course. Uses Play-Doh (plastic modeling clay) to build a multicellular embryo in order to provide a 3-D demonstration of cleavage. Includes notes for the instructor and student directions. (YDS)

Ellis, Linda K.

2000-01-01

341

BIOLOGICAL ACTIVITY AND POTENTIAL REMEDIATION INVOLVING GEOTEXTILE LANDFILL LEACHATE FILTERS  

EPA Science Inventory

This paper presents the results of a biological growth study in geotextile filters used in landfill leachate collection systems. fter reviewing the first year's activity, a completely new experimental approach has been taken. sing 100 mm diameter columns for the experimental incu...

342

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 ...

343

Synthesis and biological activity of tetralone abscisic acid analogues.  

PubMed

Bicyclic analogues of the plant hormone abscisic acid (ABA) were designed to incorporate the structural elements and functional groups of the parent molecule that are required for biological activity. The resulting tetralone analogues were predicted to have enhanced biological activity in plants, in part because oxidized products would not cyclize to forms corresponding to the inactive catabolite phaseic acid. The tetralone analogues were synthesized in seven steps from 1-tetralone and a range of analogues were accessible through a second route starting with 2-methyl-1-naphthol. Tetralone ABA 8 was found to have greater activity than ABA in two bioassays. The absolute configuration of (+)-8 was established by X-ray crystallography of a RAMP hydrazone derivative. The hydroxymethyl compounds 10 and 11, analogues for studying the roles of 8- and 9-hydroxy ABA 3 and 6, were also synthesized and found to be active. PMID:16557330

Nyangulu, James M; Nelson, Ken M; Rose, Patricia A; Gai, Yuanzhu; Loewen, Mary; Lougheed, Brenda; Quail, J Wilson; Cutler, Adrian J; Abrams, Suzanne R

2006-04-01

344

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

345

Effects of plant species coexistence on soil enzyme activities and soil microbial community structure under Cd and Pb combined pollution  

Microsoft Academic Search

The relationship between plant species coexistence and soil microbial communities under heavy metal pollution has attracted much attention in ecology. However, whether plant species coexistence could offset the impacts of heavy metal combined pollution on soil microbial community structure and soil enzymes activities is not well studied. The modified ecological dose model and PCR-RAPD method were used to assess the

Yang Gao; Pei Zhou; Liang Mao; Yueer Zhi; Chunhua Zhang; Wanjun Shi

2010-01-01

346

Field-scale cleanup of atrazine and cyanazine contaminated soil with a combined chemical-biological approach.  

PubMed

A former agrichemical dealership in western Nebraska was suspected of having contaminated soil. Our objective was to characterize and remediate the contaminated site by a combined chemical-biological approach. This was accomplished by creating contour maps of the on-site contamination, placing the top 60 cm of contaminated soil in windrows and mixing with a mechanical high-speed mixer. Homogenized soil containing both atrazine [6-chloro-N-ethyl-N'-isopropyl-1,3,5-triazine-2,4-diamine] and cyanazine {2-[[4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl] amino]-2-methylpropanenitrile} was then used in laboratory investigations to determine optimum treatments for pesticide destruction. Iron suspension experiments verified that zerovalent iron (Fe(0)) plus ferrous sulfate (FeSO(4).7H(2)O) removed more than 90% of both atrazine and cyanazine within 14 d. Liquid chromatography/mass spectrometry (LC/MS) analysis of the atrazine solution after treating with Fe(0) and ferrous sulfate identified several degradation products commonly associated with biodegradation (i.e., deethlyatrazine (DEA), deisopropylatrazine (DIA), hydroxyatrazine (HA), and ammelines). Biological treatment evaluated emulsified soybean [Glycine max (L.) Merr.] oil (EOS) as a carbon source to stimulate biodegradation in static soil microcosms. Combining emulsified soybean oil with the chemical amendments resulted in higher destruction efficiencies (80-85%) and reduced the percentage of FeSO(4) needed. This chemical-biological treatment (Fe(0) + FeSO(4) + EOS, EOS Remediation, Raleigh, NC) was then applied with water to 275 m(3) of contaminated soil in the field. Windrows were tightly covered with clear plastic to increase soil temperature and maintain soil water content. Temporal sampling (0-342 d) revealed atrazine and cyanazine concentrations decreased by 79 to 91%. These results provide evidence that a combined chemical-biological approach can be used for on-site, field-scale treatment of pesticide-contaminated soil. PMID:19643745

Waria, M; Comfort, S D; Onanong, S; Satapanajaru, T; Boparai, H; Harris, C; Snow, D D; Cassada, D A

2009-01-01

347

[Biological treatments for contaminated soils: hydrocarbon contamination. Fungal applications in bioremediation treatment].  

PubMed

Bioremediation is a spontaneous or controlled process in which biological, mainly microbiological, methods are used to degrade or transform contaminants to non or less toxic products, reducing the environmental pollution. The most important parameters to define a contaminated site are: biodegradability, contaminant distribution, lixiviation grade, chemical reactivity of the contaminants, soil type and properties, oxygen availability and occurrence of inhibitory substances. Biological treatments of organic contaminations are based on the degradative abilities of the microorganisms. Therefore the knowledge on the physiology and ecology of the biological species or consortia involved as well as the characteristics of the polluted sites are decisive factors to select an adequate biorremediation protocol. Basidiomycetes which cause white rot decay of wood are able to degrade lignin and a variety of environmentally persistent pollutants. Thus, white rot fungi and their enzymes are thought to be useful not only in some industrial process like biopulping and biobleaching but also in bioremediation. This paper provides a review of different aspects of bioremediation technologies and recent advances on ligninolytic metabolism research. PMID:15709784

Martín Moreno, Carmen; González Becerra, Aldo; Blanco Santos, María José

2004-09-01

348

Total Chemical Synthesis of Biologically Active Vascular Endothelial Growth Factor  

PubMed Central

A 204 residue covalent-dimer vascular endothelial growth factor, with full mitogenic activity, was made by one-pot native chemical ligation from three unprotected peptide segments. The covalent structure of synthetic VEGF was confirmed by precise mass measurement, and the three dimensional structure of the synthetic protein molecule was determined by high resolution X-ray crystallography. Robust, practical synthetic access to biologically active VEGF will aid in the development of novel anti-angiogenic therapeutics.

Mandal, Kalyaneswar; Kent, Stephen B. H.

2012-01-01

349

Studies on Speciation of Antimony in Soil Contaminated by Industrial Activity  

Microsoft Academic Search

Antimony is a toxic trace element of growing environmental interest due to its increased anthropogenic input into the environment. Very little is known about the chemical and biological behavior of antimony compounds in soils and sediments. Three soil samples with substantially elevated Sb concentrations (area contaminated by extensive industrial use of Sb compounds), and a soil standard reference material have

Joseph Lintschinger; Bernhard Michalke; Sigurd Schulte-hostede; Peter Schramel

1998-01-01

350

The Soil Moisture Active and Passive (SMAP) Mission  

NASA Technical Reports Server (NTRS)

The Soil Moisture Active and 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 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 significantly improved estimates of water, energy and carbon transfers between land and atmosphere. Soil moisture measurements are also of great importance in assessing flooding and monitoring drought. SMAP observations can help mitigate these natural hazards, resulting in potentially great economic and social benefits. SMAP soil moisture and freeze/thaw timing observations will also reduce a major uncertainty in quantifying the global carbon balance by helping to resolve an apparent missing carbon sink on land over the boreal latitudes. The SMAP mission concept would utilize an L-band radar and radiometer. These instruments will share a rotating 6-meter mesh reflector antenna to provide high-resolution and high-accuracy global maps of soil moisture and freeze/thaw state every two to three days. The SMAP instruments provide direct measurements of surface conditions. In addition, the SMAP project will use these observations with advanced modeling and data assimilation to provide deeper root-zone soil moisture and estimates of land surface-atmosphere exchanges of water, energy and carbon. SMAP is scheduled for a 2014 launch date

Entekhabi, Dara; Nijoku, Eni G.; ONeill, Peggy E.; Kellogg, Kent H.; Crow, Wade T.; Edelstein, Wendy N.; Entin, Jared K.; Goodman, Shawn D.; Jackson, Thomas J.; Johnson, Joel; Kimball, John; Piepmeier, Jeffrey R.; Koster, Randal D.; McDonald, Kyle C.; Moghaddam, Mahta; Moran, Susan; Reichle, Rolf; Shi, J. C.; Spencer, Michael W.; Thurman, Samuel W.; Tsang, Leung; VanZyl, Jakob

2009-01-01

351

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

352

Bioavailability and toxicity of cadmium to microorganisms and their activities in soil: a review  

Microsoft Academic Search

Significant quantities of cadmium (Cd) have been added to the soils globally due to various anthropogenic activities, raising concerns for environmental health. Microorganisms play a unique role in the soil ecosystem, because of their contributions to soil fertility. Contrasting trends, reported on the toxic effects of heavy metals including Cd on soil microorganisms and their activities, are attributable to short-term

K Vig; M Megharaj; N Sethunathan; R Naidu

2003-01-01

353

Effects of mercury on microbial biomass and enzyme activities in soil  

Microsoft Academic Search

Mercury (Hg) is a persistent soil pollutant that affects soil microbial activity. We monitored the changes in soil microbial\\u000a biomass and activity of enzymes, including alkaline phosphatase, arylsulfatase, fluorescein diacetate (FDA) hydrolytic activity,\\u000a and o-diphenol oxidase (o-DPO) in three soils contaminated with different concentrations of Hg. Increasing levels of Hg, from 0.5 to 10 µmol\\/g of dried\\u000a soil, generally depressed

Cristiano Casucci; Benedict C. Okeke; William T. Frankenberger

2003-01-01

354

Nondestructive neutron activation analysis of some soil clays of Egypt  

Microsoft Academic Search

Fourteen clay samples separated from calcareous, lacustrine, Nile alluvium and desert alluvium soils of Egypt were analyzed by pure instrumental neutron activation analysis. Elemental composition was determined by high resolution gamma-spectrometry on samples irradiated with reactor neutrons using the monostrandard technique. This was carried out in the nuclear research center of Karlsruhe, West Germany. As many as 17 trace elements,

R. Zaghloul; S. El-Demerdashe; M. A. Abdel-Salam; E. A. Bakhoum

1987-01-01

355

Soil moisture effects on the activity of three entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) isolated from Meghalaya, India.  

PubMed

Entomopathogenic nematodes (EPNs) are obligate parasites of insects that are widely distributed in soils throughout the world. They have great potential for use as biological control agents for insect pests. It is known that strains of Steinernema and Heterorhabditis isolated from different geographical regions exhibit differences in their ecological traits, such as infectivity, establishment, survival, reproduction, etc. A precise knowledge of these factors is therefore an essential pre-requisite for devising successful strategies to use these nematodes in biological control programmes. The present study investigated the effect of soil moisture on the activity (as measured by number of nematodes established in hosts) of three entomopathogenic nematode species (Heterorhabditis indica Poinar, Karunakar & David; Steinernema thermophilum Ganguly & Singh; Steinernema glaseri Steiner), isolated from forest soils in Meghalaya, India, under laboratory conditions. The experiments for EPNs were conducted at 25 ± 2°C (30 ± 2°C for S. thermophilum) in a sandy loam soil (85% sand, 12% silt and 3% clay, pH 6.54). Last instar larvae of wax moth, Galleria mellonella served as the experimental insect host. The soil moistures tested were 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 25% (w/w). The study revealed that soil moisture has marked influences on establishment of infective juveniles of different nematode species in insect host. While, S. thermophilum showed establishment at 4% and above soil moistures, H. indica and S. glaseri showed establishment at 5% and above soil moistures. The optimum soil moisture for different nematode species were noted as: H. indica 8-18%, S. thermophilum 6-20%, and S. glaseri 8-25%. Further, a minimum of 6% soil moisture was noted to be essential for achieving 100% host mortality for all the three nematode species. PMID:23543771

Yadav, Arun K; Lalramliana

2012-04-01

356

Biological Activities of Phenolic Compounds Present in Virgin Olive Oil  

PubMed Central

The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, neurodegenerative diseases and certain types of cancer. The apparent health benefits have been partially ascribed to the dietary consumption of virgin olive oil by Mediterranean populations. Much research has focused on the biologically active phenolic compounds naturally present in virgin olive oils to aid in explaining reduced mortality and morbidity experienced by people consuming a traditional Mediterranean diet. Studies (human, animal, in vivo and in vitro) have demonstrated that olive oil phenolic compounds have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, antimicrobial activity and bone health. This paper summarizes current knowledge on the bioavailability and biological activities of olive oil phenolic compounds.

Cicerale, Sara; Lucas, Lisa; Keast, Russell

2010-01-01

357

Propolis volatile compounds: chemical diversity and biological activity: a review  

PubMed Central

Propolis is a sticky material collected by bees from plants, and used in the hive as building material and defensive substance. It has been popular as a remedy in Europe since ancient times. Nowadays, propolis use in over-the-counter preparations, “bio”-cosmetics and functional foods, etc., increases. Volatile compounds are found in low concentrations in propolis, but their aroma and significant biological activity make them important for propolis characterisation. Propolis is a plant-derived product: its chemical composition depends on the local flora at the site of collection, thus it offers a significant chemical diversity. The role of propolis volatiles in identification of its plant origin is discussed. The available data about chemical composition of propolis volatiles from different geographic regions are reviewed, demonstrating significant chemical variability. The contribution of volatiles and their constituents to the biological activities of propolis is considered. Future perspectives in research on propolis volatiles are outlined, especially in studying activities other than antimicrobial.

2014-01-01

358

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

359

Influence of altered precipitation pattern on greenhouse gas emissions and soil enzyme activities in Pannonian soils  

NASA Astrophysics Data System (ADS)

Precipitation patterns are likely to be altered due to climate change. Recent models predict a reduction of mean precipitation during summer accompanied by a change in short-term precipitation variability for central Europe. Correspondingly, the risk for summer drought is likely to increase. This may especially be valid for regions which already have the potential for rare, but strong precipitation events like eastern Austria. Given that these projections hold true, soils in this area will receive water irregularly in few, heavy rainfall events and be subjected to long-lasting dry periods in between. This pattern of drying/rewetting can alter soil greenhouse gas fluxes, creating a potential feedback mechanism for climate change. Microorganisms are the key players in most soil carbon (C) and nitrogen (N) transformation processes including greenhouse gas exchange. A conceptual model proposed by Schimel and colleagues (2007) links microbial stress-response physiology to ecosystem-scale biogeochemical processes: In order to cope with decreasing soil water potential, microbes modify resource allocation patterns from growth to survival. However, it remains unclear how microbial resource acquisition via extracellular enzymes and microbial-controlled greenhouse gas fluxes respond to water stress induced by soil drying/rewetting. We designed a laboratory experiment to test for effects of multiple drying/rewetting cycles on soil greenhouse gas fluxes (CO2, CH4, N2O, NO), microbial biomass and extracellular enzyme activity. Three soils representing the main soil types of eastern Austria were collected in June 2012 at the Lysimeter Research Station of the Austrian Agency for Health and Food Safety (AGES) in Vienna. Soils were sieved to 2mm, filled in steel cylinders and equilibrated for one week at 50% water holding capacity (WHC) for each soil. Then soils were separated into two groups: One group received water several times per week (C=control), the other group received water only once in two weeks (D=dry). Both groups received same water totals for each soil. At the end of each two week drying period, greenhouse gas fluxes were measured via an open-chamber-system (CO2, NO) and a closed-chamber-approach (CH4, N2O, CO2). Additional cylinders were harvested destructively to quantify inorganic N forms, microbial biomass C, N and extracellular enzyme activity (Cellulase, Xylanase, Protease, Phenoloxidase, Peroxidase). We hypothesize that after rewetting (1) rates of greenhouse gas fluxes will generally increase, as well as (2) extracellular enzyme activity indicating enhanced microbial activity. However, response may be different for gases and enzymes involved in the C and N cycle, respectively, as drying/rewetting stress may uncouple microbial mediated biogeochemical cycles. Results will be presented at the EGU General Assembly. Reference: Schimel, J., Balser, T.C., and Wallenstein, M. (2007). Microbial stress-response physiology and its implications for ecosystem function. Ecology 88, 1386-1394.

Forstner, Stefan Johannes; Michel, Kerstin; Berthold, Helene; Baumgarten, Andreas; Wanek, Wolfgang; Zechmeister-Boltenstern, Sophie; Kitzler, Barbara

2013-04-01

360

The activation energy of stabilised/solidified contaminated soils.  

PubMed

Developing an understanding of the time-related performance of cement-treated materials is essential in understanding their durability and long-term effectiveness. A number of models have been developed to predict this time-related performance. One such model is the maturity concept which involves use of the 'global' activation energy which derives from the Arrhenius equation. The accurate assessment of the activation energy is essential in the realistic modelling of the accelerated ageing of cement-treated soils. Experimentally, this model is applied to a series of tests performed at different elevated temperatures. Experimental work, related to the results of a time-related performance on a contaminated site in the UK treated with in situ stabilisation/solidification was carried out. Three different cement-based grouts were used on two model site soils which were both contaminated with a number of heavy metals and a hydrocarbon. Uncontaminated soils were also tested. Elevated temperatures up to 60 degrees C and curing periods up to 90 days were used. The resulting global activation energies for the uncontaminated and contaminated soils were compared. Lower values were obtained for the contaminated soils reflecting the effect of the contaminants. The resulting equivalent ages for the uncontaminated and contaminated mixes tested were 5.1-7.4 and 0.8-4.1 years, respectively. This work shows how a specific set of contaminants affect the E(a) values for particular cementitious systems and how the maturity concept can be applied to cement-treated contaminated soils. PMID:16839664

Chitambira, B; Al-Tabbaa, A; Perera, A S R; Yu, X D

2007-03-15

361

Effects of heat-activated persulfate oxidation on soil microorganisms.  

PubMed

The effects of heat-activated persulfate on indigenous microorganisms and microcosms augmented with Pseudomonas putida KT2440 were studied in laboratory batch reactors with aquifer material. Microscopic enumeration was used to measure the changes in cell density, and acetate consumption was used to evaluate metabolic activity after exposure to activated persulfate. The cell enumerations showed that persulfate concentrations up to 10 g/L did not affect the indigenous microorganisms but were detrimental to P. putida survival. Acetate consumption was inhibited at the highest persulfate dose (10 g/L). The results emphasize the necessity of using multiple toxicity assays and indigenous cultures in order to realistically assess the potential effects of in situ chemical oxidation on soil microorganisms. A comparison to other studies suggests that the effects of activated persulfate on soil microorganisms are less damaging than those of Fenton's reagent and hydrogen peroxide. PMID:17942135

Tsitonaki, Aikaterini; Smets, Barth F; Bjerg, Poul L

2008-02-01

362

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.

363

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

364

Study of the soil isolates for antimicrobial activity.  

PubMed

During the process of screening for a potent antimicrobial compound, a new strain was isolated from the soil sample of Thalaikunda village in Ooty, Tamil Nadu. That organism was name as NK(2). It was found to be antagonistic to both bacterial and fungal test organisms. Production of antibiotic was more in a newly formulated broth. Antibiotic production reached maximum at the end of the 70 h of fermentation by stirred flask culture. The antimicrobial compound was extracted in n-butanol, ethyl acetate and methanol. Antimicrobial compound, which was produced by the soil isolate NK(2) did not showed cytotoxic activity on Vero cell lines. PMID:21369451

Srividya, A R; Saritha, G S; Suresh, B

2008-11-01

365

Chloramphenicol Inhibition of Denitrifying Enzyme Activity in Two Agricultural Soils  

Microsoft Academic Search

Chloramphenicol, at concentrations greater than 0.1 g\\/liter (0.3 mM), inhibited the denitrifying enzyme activity (DEA) of slurries of humisol and sandy loam soils by disrupting the activity of existing nitrate reductase enzymes. When the concentration of chloramphenicol was increased from 0.1 to 2.0 g\\/liter (6.0 mM), the rate of nitrite production from nitrate decreased by 25 to 46%. The rate

ROBERT E. MURRAY; ROGER KNOWLES

1999-01-01

366

Biological maturity and primary school children's physical activity: Influence of different physical activity assessment instruments  

Microsoft Academic Search

Biological maturation may attenuate hypothesized sex differences in children's physical activity but overall the evidence for this is equivocal. In this study, we investigated how the selection of different physical activity assessment instruments affects the detected relationship between biological maturation and late primary school children's physical activity. Altogether, 175 children (97 girls, 78 boys) aged 10.6±0.3 years completed the PAQ-C

Stuart J. Fairclough; Lynne M. Boddy; Nicola D. Ridgers; Gareth Stratton; Sean Cumming

2011-01-01

367

Microbial activity in soils following steam treatment  

Microsoft Academic Search

Steam enhanced extraction (SEE) is an aquifer remediation technique that can be effective at removing the bulk of non-aqueous phase liquid (NAPL) contamination from the subsurface, particularly highly volatile contaminants. However, low volatility compounds such as polynuclear aromatic hydrocarbons (PAHs) are less efficientlyremoved by this process. This research evaluated the effects of steam injection on soilmicrobial activity, community structure, and

Ruth E. Richardson; C. Andrew James; Vishvesh K. Bhupathiraju; Lisa Alvarez-Cohen

2002-01-01

368

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, Geneviève; Bouchard, Adeline; Monserié, Marie-France; Séré, Geoffroy; Schwartz, Christophe; Morel, Jean-Louis

2010-05-01

369

Determination of urease activity in soils by carbon dioxide release for ecotoxicological evaluation of contaminated soils.  

PubMed

A method for the quantification of urease enzyme activity has been set up, which is based on the quantification of carbon dioxide set free into the head space of gastight vessels. The method can be applied for ecotoxicological characterisation of contaminated soil samples besides other methods like soil respiration measurements or nitrification inhibition tests. The sieved soil sample can be incubated under nearly natural conditions with an adjusted water content of about 50% of the water holding capacity. Ammonia or urea do not need to be extracted, since carbon dioxide release is correlated to urease activity. Thus carbon dioxide release is a direct result of urease activity which can be measured in the head space using gastight syringes and gaschromatographic equipment. The urease activity is determined by comparing the carbon dioxide release of incubation vessels with and without urea supply. The applicability of this method has been demonstrated by experiments with N-(n-butyl)phosphoric triamide (NBPT), copper ions and zinc ions as known inhibitors of urease activity. PMID:12463682

Guettes, Ralf; Dott, Wolfgang; Eisentraeger, Adolf

2002-10-01

370

Impacts of simulated acid rain on soil enzyme activities in a latosol.  

PubMed

Acid rain pollution is a serious environmental problem in the world. This study investigated impacts of simulated acid rain (SAR) upon four types of soil enzymes, namely the catalase, acid phosphatase, urease, and amylase, in a latosol. Latosol is an acidic red soil and forms in the tropical rainforest biome. Laboratory experiments were performed by spraying the soil columns with the SAR at pH levels of 2.5, 3.0, 3.5., 4.0, 4.5, 5.0, and 7.0 (control) over a 20-day period. Mixed results were obtained in enzyme activities for different kinds of enzymes under the influences of the SAR. The catalase activities increased rapidly from day 0 to 5, then decreased slightly from day 5 to 15, and finally decreased sharply to the end of the experiments, whereas the acid phosphatase activities decreased rapidly from day 0 to 5, then increased slightly from day 5 to 15, and finally decreased dramatically to the end of the experiments. A decrease in urease activities was observed at all of the SAR pH levels for the entire experimental period, while an increase from day 0 to 5 and then a decrease from day 5 to 20 in amylase activities were observed at all of the SAR pH levels. In general, the catalase, acid phosphatase, and urease activities increased with the SAR pH levels. However, the maximum amylase activity was found at pH 4.0 and decreased as the SAR pH increased from 4.0 to 5.0 or decreased from 4.0 to 2.5. It is apparent that acid rain had adverse environmental impacts on soil enzyme activities in the latosol. Our study further revealed that impacts of the SAR upon soil enzyme activities were in the following order: amylase>catalase>acid phosphatase>urease. These findings provide useful information on better understanding and managing soil biological processes in the nature under the influence of acid rains. PMID:20701974

Ling, Da-Jiong; Huang, Qian-Chun; Ouyang, Ying

2010-11-01

371

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

372

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

373

A limulus amoebocyte lysate activating activity (LAL activity) that lacks biological activities of endotoxin found in biological products.  

PubMed

Pyrogenic substances in influenza HA (IHA) vaccine have been controlled by the pyrogen test or the mouse body weight decreasing toxicity (BWD) test. We examined the possibility of replacing the animal tests with the endotoxin test Commercial IHA vaccines were found to show considerable levels of LAL activity ranging from 0.2 to 160 EU/ml. However, a batch of the vaccine having even 100 EU/ml of LAL activity showed neither pyrogenicity in rabbits nor tumor necrosis factor alpha (TNF-alpha) induction in RAW264.7 cells. The LAL activity of IHA vaccine was abolished by a monoclonal antibody that recognizes LPS-binding epitope of LAL factor C. The activity of IHA vaccine showed different physicochemical properties from those of LAL activity of endotoxin. LAL activity of endotoxin is known to be sensitive to polymyxin B treatment and was found to be resistant to polyoxyethylene 10 cetyl ether (Brij56) treatment. On the contrary, the LAL activity of IRA vaccine was shown to be resistant to polymyxin B but sensitive to Brij56 treatment. The difference in sensitivity of the two LAL activities to polymyxin B and Brij56 might suggest the possibility of their discriminative measurements. PMID:12363016

Ochia, Masaki; Tamura, Hiroshi; Yamamoto, Akihiko; Aizawa, Maki; Kataoka, Michiyo; Toyoizumi, Hiromi; Horiuchi, Yoshinobu

2002-01-01

374

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

375

[Effects of forest type on soil organic matter, microbial biomass, and enzyme activities].  

PubMed

Taking the typical forest types Pinus elliottii var. elliotttii, Araucaria cunninghamii, and Agathis australis in southern Queensland of Australia as test objects, an investigation was made on the soil soluble organic carbon (SOC) and nitrogen (SON), microbial biomass C (MBC) and N (MBN), and enzyme activities, aimed to understand the effects of forest type on soil quality. In the three forests, soil SOC content was 552-1154 mg kg(-1), soil SON content was 20.11-57.32 mg kg(-1), soil MBC was 42-149 mg kg(-1), soil MBN was 7-35 mg kg(-1), soil chitinase (CAS) activity was 2.96-7.63 microg g(-1) h(-1), soil leucine aminopeptidase (LAP) activity was 0.18-0.46 microg g(-1) d(-1), soil acid phosphatase (ACP) activity was 16.5-29.6 microg g(-1) h(-1), soil alkaline phosphatase (AKP) activity was 0.79-3.42 microg g(-1) h(-1), and soil beta-glucosidase (BG) activity was 3.71-9.93 microg g(-1) h(-1). There was a significant correlation between soil MBC and MBN. Soil SOC content and soil CAS and LAP activities decreased in the order of P. elliottii > A. cunninghamii > A. australis, soil SON content decreased in the order of A. cunninghamii > A. australis > P. elliottii and was significantly higher in A. cunninghamii than in P. elliottii forest (P < 0.05), soil MBC and MBN and AKP activity decreased in the order of A. australis > P. elliottii > A. cunninghamii, and soil ACP and BG activities decreased in the order of P. elliottii > A. australis > A. cunninghamii. Among the test soil biochemical factors, soil MBC, MBN, SON, and LAP had greater effects on the soil quality under the test forest types. PMID:22263459

Lu, Shun-bao; Zhou, Xiao-qi; Rui, Yi-chao; Chen, Cheng-rong; Xu, Zhi-hong; Guo, Xiao-min

2011-10-01

376

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.

Pal, Dilipkumar; Mishra, Pragya; Sachan, Neetu; Ghosh, Ashoke K.

2011-01-01

377

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.

Burri, Lena; Hoem, Nils; Banni, Sebastiano; Berge, Kjetil

2012-01-01

378

Biological activities and medicinal properties of Gokhru (Pedalium murex L.)  

PubMed Central

Bada Gokhru (Pedalium murex L.) 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 Pedalium murex compounds, considerable progress has been achieved regarding the biological activity and medicinal applications of this plant. It is now considered as a valuable source of unique natural products for development of medicines against various diseases and also for the development of industrial products. This review gives a bird's eye view mainly on the biological activities of some of this compounds isolated, pharmacological actions of the extracts, clinical studies and plausible medicinal applications of gokharu along with their safety evaluation.

Rajashekar, V; Rao, E Upender; P, Srinivas

2012-01-01

379

Biological activities and medicinal properties of Gokhru (Pedalium murex L.).  

PubMed

Bada Gokhru (Pedalium murex L.) 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 Pedalium murex compounds, considerable progress has been achieved regarding the biological activity and medicinal applications of this plant. It is now considered as a valuable source of unique natural products for development of medicines against various diseases and also for the development of industrial products. This review gives a bird's eye view mainly on the biological activities of some of this compounds isolated, pharmacological actions of the extracts, clinical studies and plausible medicinal applications of gokharu along with their safety evaluation. PMID:23569975

Rajashekar, V; Rao, E Upender; P, Srinivas

2012-07-01

380

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

Microsoft Academic Search

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

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

2011-01-01