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1

Evaluation of soil biological activity after a diesel fuel spill.  

PubMed

Diesel fuel contamination in soils may be toxic to soil microorganisms and plants and acts as a source of groundwater contamination. The objective of this study was to evaluate the soil biological activity and phytotoxicity to garden cress (Lepidium sativum L.) in a soil polluted with diesel fuel. For this, a diesel fuel spill was simulated on agricultural soil at dose 1 l m(-2). During the experiment (400 days) the soil was not covered in vegetation and no agricultural tasks were carried out. A stress period of 18 days following the spill led to a decrease in soil biological activity, reflected by the soil microbial biomass and soil enzymatic activities, after which it increased again. The n-C(17)/Pristine and n-C(18)/Phytane ratios were correlated negatively and significantly with the dehydrogenase, arylsulphatase, protease, phosphatase and urease activities and with the soil microbial biomass during the course of the experiment. The beta-glucosidase activity indicated no significant connection with the parameters related with the evolution of hydrocarbons in the soil. Finally, the germination activity of the soil was seen to recover 200 days after the spill. PMID:19395000

Serrano, A; Tejada, M; Gallego, M; Gonzalez, J L

2009-06-15

2

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

3

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

E-print Network

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

Minnesota, University of

4

Detection and Investigation of Soil Biological Activity against Meloidogyne incognita  

PubMed Central

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

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

2008-01-01

5

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

Microsoft Academic Search

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

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

1985-01-01

6

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 ...

7

Suitability of dehydrogenase activity assay as an index of soil biological activity  

Microsoft Academic Search

Dehydrogenase activity was studied in typical soils of the Northwest German Lower Plains in order to test some criticisms raised by nannipieri et al. (1990) about methodology. We found that in the same soils with the sampe crop, dehydrogenase activity varies significantly. In the field dehydrogenase activity was dependent on the soil type and not on the cropping system. There

Lothar Beyer; Christine Wachendorf; Dirk C. Elsner; Roland Knabe

1993-01-01

8

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

9

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

E-print Network

Soil Biology & Biochemistry 39 (2007) 1014­1022 Influence of earthworm activity on aggregate 18 November 2006 Available online 26 December 2006 Abstract Earthworms are known to be important population densities of the earthworm Aporrectodea rosea in three maize-tomato cropping systems [conventional

van Kessel, Chris

10

Changes in soil structure and biological activity on some meadow hay plots at Cockle Park, Northumberland  

Microsoft Academic Search

Summary The accumulation of organic matter to form an organic horizon on one of the Palace Leas meadow hay plots has resulted from the effects of ammonium sulphate application over a period of 86 years. Associated with this accumulation is a reduction in biological activity, deterioration in hydrologic conditions and an increase in soil bulk density. The primary cause of

R. S. Shiel; D. L. Rimmer

1984-01-01

11

Impact of Fungicide Mancozeb at Different Application Rates on Soil Microbial Populations, Soil Biological Processes, and Enzyme Activities in Soil  

PubMed Central

The use of fungicides is the continuous exercise particularly in orchard crops where fungal diseases, such as white root rot, have the potential to destroy horticultural crops rendering them unsaleable. In view of above problem, the present study examines the effect of different concentrations of mancozeb (0–2000?ppm) at different incubation periods for their harmful side effects on various microbiological processes, soil microflora, and soil enzymes in alluvial soil (pH 6.8) collected from apple orchards of Shimla in Himachal Pradesh (India). Low concentrations of mancozeb were found to be deleterious towards fungal and actinomycetes population while higher concentrations (1000 and 2000?ppm) were found to be detrimental to soil bacteria. Mancozeb impaired the process of ammonification and nitrification. Similar results were observed for nitrifying and ammonifying bacteria. Phosphorus solubilization was increased by higher concentration of mancozeb, that is, 250?ppm and above. In unamended soil, microbial biomass carbon and carbon mineralization were adversely affected by mancozeb. Soil enzymes, that is, amylase, invertase, and phosphatase showed adverse and disruptive effect when mancozeb used was above 10?ppm in unamended soil. These results conclude that, to lessen the harmful effects in soil biological processes caused by this fungicide, addition of higher amount of nitrogen based fertilizers is required. PMID:25478598

Mehta, Preeti; Guleria, Shiwani; Chauhan, Anjali; Shirkot, C. K.

2014-01-01

12

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

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

13

Impact of reclamation treatment on the biological activity of soils of the solonetz complex in Western Siberia  

NASA Astrophysics Data System (ADS)

The abundance and activity of the soil microflora were studied in a field experiment with the use of green manure crops to assess the impact of reclamation measures on the biological activity of soils of the solonetz complex. The number of microorganisms in the plow soil horizon increased in the background of the green fallows as compared to the black ones. Coefficients of mineralization, immobilization, and transformation of organic compounds were calculated for different variants of the soil treatment. The value of the mineralization coefficient indicates the intense decomposition of the green manure that entered the soil. In the first year, peas were actively decomposed, while oats, in the second year (aftereffect). The activity of the soil enzymes (invertase, urease, and catalase) was determined. A close relationship between the catalase activity and the intensity of the microbiological processes in the soils was revealed.

Berezin, L. V.; Khamova, O. F.; Paderina, E. V.; Gindemit, A. M.

2014-11-01

14

Soil Biological Communities  

NSDL National Science Digital Library

The Bureau of Land Management (BLM) in Idaho provides this electronic resource on soil communities. With introductory text, illustrations, and references, these pages provide a general overview of soil communities, including Biological Crusts, Fungi, Bacteria, Protozoa, Nematodes, and Arthropods. The site also introduces general readers to Soil Food Webs and Burrowing Mammals, with an emphasis on the western United States. A series of select links to soil-related resources rounds out the site.

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

Biological Soil Crusts  

NSDL National Science Digital Library

Biological soil crust probably isn't the first thing that springs to mind when snapping that photo of the Delicate Arch at Arches National Park. However, without the algae, mosses, cyanobacteria, and other tiny organisms that inhabit the surface of desert soils, places like Arches and other arid environments would be quite different. The US Geological Survey provides an online guide to biological soil crusts in this easy-to-navigate Web site. Crust 101 contains a detailed introduction to soil crust ecology, and the Advanced feature offers an extensive technical reference. The Web site also includes a photo gallery, list of related references, and a short list of links. This site is also reviewed in the November 27, 2002 Scout Report.

1969-12-31

18

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

Microsoft Academic Search

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

Kerstin M. Witte; Richard B. Wanty; W. Ian Ridley

2004-01-01

19

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

E-print Network

1 Soil invertebrate activity in biological crusts on tropical inselbergs A.VAÃ?ULIK, C. KOUNDA invertebrates, in particular enchytraeid worms, are important for the accumulation of organic matter on granite: Soil invertebrate activity in biological crusts Introduction Inselbergs protrude from rain forests

Paris-Sud XI, Université de

20

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

21

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

22

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

23

Spatial and temporal patterns of soil biological activity in a forest and an old field  

Microsoft Academic Search

The spatial distribution of C mineralization, nematode density, organic matter content and soil moisture were determined for a forest and an old field soil in the northeastern U.S.A. over the course of a year. The data were analyzed using univariate, multivariate and geostatistical methods. The forest soil had a higher C mineralization rate, soil moisture content and nematode density than

Josef H. Görres; Marnie J. Dichiaro; Jodi B. Lyons; José A. Amador

1998-01-01

24

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

25

Antibiotic pigment from desert soil actinomycetes; biological activity, purification and chemical screening.  

PubMed

An actinomycete strain, Streptomyces hygroscopicus subsp. ossamyceticus (strain D10) was isolated from Thar Desert soil, Rajasthan during the year 2006 and found to produce a yellow color pigment with antibiotic activity. Crude pigment was produced from strain D10 by solid state fermentation using wheat bran medium followed by extraction with ethyl acetate. The antimicrobial activity of the crude pigment was evaluated against drug resistant pathogens such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant Staphylococcus aureus, extended spectrum beta-lactamase producing cultures of Escherichia coli, Pseudomonas aeruginosa and Klebsiella sp. About 420 mg of crude pigment was produced per 10 g of wheat bran medium. In the disc diffusion method the crude ethyl acetate extract showed a minimum of 10 mm inhibition against Klebsiella sp. and maximum of 19 mm of inhibition against Escherichia coli. The crude pigment was partially purified using thin layer chromatography with the solvent system chloroform:methanol (30:70) and the Rf value was calculated as 0.768. Antimicrobial activity of the partially purified compound from thin layer chromatography was determined using the bioautography method. The purified pigment showed minimum of 15 mm inhibition against Klebsiella sp. and a maximum of 23 mm of inhibition against vancomycin-resistant Staphylococcus aureus in the disc diffusion method. Based on the results of chemical screening, the pigment was tentatively identified as group of sugar containing molecules. PMID:20502566

Selvameenal, L; Radhakrishnan, M; Balagurunathan, R

2009-09-01

26

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

EPA Science Inventory

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

27

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

EPA Science Inventory

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

28

Soil Biology & Biochemistry ] (  

E-print Network

and are expected to increase in area due to global warming and desertifica- tion. Nitrogen limitation to plant, is becoming increasingly more important with persistent predictions of warming and drying trends over clearing did not have a significant influence on the soil N in the semi-arid rangelands (Harms et al., 2005

Yakir, Dan

29

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

USGS Publications Warehouse

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

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

1989-01-01

30

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

PubMed

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

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

2009-06-01

31

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

32

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

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

33

LAND USE HISTORY, SOIL BIOLOGY, AND SOIL CARBON  

Technology Transfer Automated Retrieval System (TEKTRAN)

Land use history contributes to patterns in soil biology and nutrient cycling. In California, a range of soil types support grasslands, each consisting of specific soil factors that influence the associated grassland and microbial communities. In Monterey County in the Central Coast region, several ...

34

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

35

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. PMID:10742249

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

2000-01-01

36

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

37

Effects of Heavy Metals on Soil Enzyme Activities  

Microsoft Academic Search

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

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

38

Just For Kids: Soil Biological Communities  

NSDL National Science Digital Library

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

39

Viking Biology Experiments and the Martian soil  

NASA Technical Reports Server (NTRS)

The Viking Biology Experiments (VBE) are the most informative database on the wet chemistry and reactivity of the Martian soil available today. The simulation and chemical interpretation of the results have given valuable hints towards the characterization of the soils' mineralogy, adsorption properties, pH and redox. The characterization of Mars' soil on the basis of ten years of labelled release (LR) and other VBE simulations are reviewed.

Banin, Amos

1989-01-01

40

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

E-print Network

Soil Biology & Biochemistry 38 (2006) 2292­2299 Modifications of degradation-resistant soil organic matter by soil saprobic microfungi Veronika R eza´ c ova´ a,b,�, Hana Hrs elova´ a , Hana Gryndlerova in their solutions and in sterile soil by microfungal species and two well-known HA degraders were studied

Miksik, Ivan

41

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

E-print Network

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

Rilli, Matthias C.

42

Microbial Activity in Frozen Soils  

Microsoft Academic Search

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

Nicolai S. Panikov

43

Impacts of off-road vehicles on nitrogen cycles in biological soil crusts: resistance in different U.S. deserts  

Microsoft Academic Search

Biological soil crusts are an important component of desert ecosystems, as they influence soil stability and fertility. This study examined and compared the short-term vehicular impacts on lichen cover and nitrogenase activity (NA) of biological soil crusts. Experimental disturbance was applied to different types of soil in regions throughout the western U.S. (Great Basin, Colorado Plateau, Sonoran, Chihuahuan, and Mojave

Jayne Belnap

2002-01-01

44

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

45

[Biological activity of Spirulina].  

PubMed

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

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

2001-01-01

46

Orchard floor management effects on nitrogen fertility and soil biological activity in a newly established organic apple orchard  

Technology Transfer Automated Retrieval System (TEKTRAN)

Nutrient supply in organic systems is dependent on mineralization of organic matter; however, the intensive cultivation commonly used to control weeds can disrupt biological processes and cause undue loss of organic matter. Here we address the often-competing goals of organic fertility and weed con...

47

Active Biological Materials  

PubMed Central

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. PMID:18999991

Fletcher, Daniel A.; Geissler, Phillip L.

2011-01-01

48

Disturbance and Recovery of Biological Soil Crusts  

Microsoft Academic Search

\\u000a Disturbance can profoundly affect the cover, species composition, and the physiological functioning of biological soil crusts.\\u000a The disturbances we discuss include air pollution; exposure to oil, herbicides, and pesticides; invasion by annual exotic\\u000a weeds; mechanical disturbances such as human and livestock trampling (see Chap. 29), off-road driving, mining, and hiking;\\u000a and, briefly, wildfire (for extensive discussion, see Chap. 28). Studies

J. Belnap; D. Eldridge

49

Biological functioning of PAH-polluted and thermal desorption-treated soils assessed by fauna and microbial bioindicators  

Microsoft Academic Search

A large number of soil bioindicators were used to assess biological diversity and activity in soil polluted with polycyclic aromatic hydrocarbons (PAHs) and the same soil after thermal desorption (TD) treatment. Abundance and biodiversity of bacteria, fungi, protozoa, nematodes and microarthropods, as well as functional parameters such as enzymatic activities and soil respiration, were assessed during a two year period

Aurélie Cébron; Jérôme Cortet; Stéven Criquet; Asmaa Biaz; Virgile Calvert; Cécile Caupert; Céline Pernin; Corinne Leyval

50

Biological and Environmental Engineering Soil & Water Research Group  

E-print Network

Biological and Environmental Engineering Soil & Water Research Group Creating a Topographic Index and Environmental Engineering Soil & Water Research Group · Topographic Index maps are grids derived from digital in GWLF, SWAT. #12;Biological and Environmental Engineering Soil & Water Research Group · Topographic

Walter, M.Todd

51

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

52

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

53

RESPONSE OF SOIL MICROBIOLOGICAL ACTIVITIES TO CD, PB, AND ZN SALT AMENDMENTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Heavy metal pollution of soil has been recognized as a major factor impeding soil microbial processes. We studied responses of the soil biological activities to metal stress simulated by soil amendment with Zn, Pb and Cd chlorides. The amounts of heavy metal salts added to five metal polluted soils ...

54

In situ fixation of metals in soils using bauxite residue: biological effects.  

PubMed

Soils polluted with heavy metals can cause phytotoxicity and exhibit impared microbial activities. In this paper we evaluate the responses of different biological endpoints to in situ remediation processes. Three soil amendments (red mud, beringite and lime) were applied to two soils polluted by heavy metals. Oilseed rape, wheat, pea and lettuce were grown successively in pots on the untreated and amended soils and their yield and metal uptake were determined. A suite of microbial tests (lux-marked biosensors, Biolog and soil microbial biomass) were performed to determine the effect of the soil amendments on the functionality and size of the soil microbial community. In both soils all three amendments reduced phytotoxicity of heavy metals, enhanced plant yields and decreased the metal concentrations in plants. The red mud treatment also increased soil microbial biomass significantly. The microbial biosensors responded positively to the remediation treatments in the industrially-contaminated soil used in the experiment. Red mud applied at 2% of soil weight was as effective as beringite applied at 5%. The results also showed that since the biological systems tested respond differently to the alleviation of metal toxicity, a suite of biological assays should be used to assess soil remediation processes. PMID:12009143

Lombi, Enzo; Zhao, Fang-Jie; Wieshammer, Gerlinde; Zhang, Gangya; McGrath, Steve P

2002-01-01

55

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

56

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

E-print Network

Author's personal copy Soil Biology & Biochemistry 39 (2007) 2138­2149 Heterogeneity of soil Laboratory, 999-W, Aiken, SC 29808, USA f Department of Plant & Soil Science, University of Vermont, Hills to have a highly heterogeneous distribution of nutrients and soil biota, with greater concentrations

Neher, Deborah A.

57

Biological Features of the Soil: Advanced Crop and Soil Science. A Course of Study.  

ERIC Educational Resources Information Center

The course of study represents the third of six modules in advanced crop and soil science and introduces the agriculture student to biological features of soil. Upon completing the two day lesson, the student will: (1) realize the vast amount of life present in the soil, (2) be able to list representative animal and plant life in the soil by size,…

Miller, Larry E.

58

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

E-print Network

are supplied by a variety of sources in the desert food web; both vascular and non-vascular plants. Keywords Colorado Plateau . Soil fauna . Desert . Soil food webs . Islands of fertility IntroductionREGULAR ARTICLE Impact of biological soil crusts and desert plants on soil microfaunal community

Neher, Deborah A.

59

Soil Biology & Biochemistry 40 (2008) 8596 Microbially available carbon in buried riparian soils  

E-print Network

Soil Biology & Biochemistry 40 (2008) 85­96 Microbially available carbon in buried riparian soils 2007 Available online 9 August 2007 Abstract Buried horizons and lenses in riparian soil profiles 14 riparian zones Rhode Island, USA, where soil profiles are characterized by glacial outwash

Gurwick, Noel P.

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

Impact of an intensive management on soil biochemical and biological properties in an agricultural soil of Southern Italy  

NASA Astrophysics Data System (ADS)

An intensive management of agricultural soils is widely carried out to increase vegetation productivity. Nevertheless, the large use of machineries, chemical fertilizers and pesticides can often cause, in time, a substantial decline in soil fertility by affecting soil physical and chemical properties and, in turn, growth and activity of soil microbial community. In fact, alteration in soil structure, nutrient losses and, in particular, changes in quality and quantity of soil organic matter are some of the principal soil degradation processes deriving from an intensive agricultural management that can affect, in different ways, soil biochemical and biological properties. The aim of this research was to assess the impact of intensive management on agricultural soils by measuring soil physical, chemical and biochemical/biological properties. The use of appropriate indicators as quantitative tools could allow to assess soil quality. Moreover, although soil physical and chemical properties have received great attention, soil biochemical/biological properties, such as enzyme activities and microbial biomass, functionally related properties involved in the nutrient cycles, can be considered as sensitive indicators of soil quality and health changes because, they show a faster turn over compared to soil organic matter. Our attention was focused on the Plane of Sele river (Campania region, Italy), an area characterized by an intensive agriculture and greenhouse cultures. Twenty-five farms were chosen, with the aid of regional soil map, in order to get soils with different physical and chemical properties. As common trait, the selected farms, all with greenhouse cultures, used no organic amendments but only mineral compounds to fertilize soils. Moreover, to better understand the impact of intensive agricultural practices on soil of each farm, control soils from orchards or uncultivated plots were chosen. In each farm soil samples were collected in three different plots within a greenhouse or within a field, for control soils. Every sample was formed by 5 sub-samples collected in 5 different points following a W scheme in the plot. All samples, sieved at 2 mm mesh, were stored at 4 °C and characterized by analysing the following soil physical and chemical, properties: soil texture, bulk density, water content, water holding capacity, pH, cation exchange capacity, organic carbon, total nitrogen, phosphorus, potassium, sodium, lime, and electrical conductivity were determined. Moreover the activity of dehydrogenase, beta-glucosidase, urease, phosphatase, and arilsulphatase, the enzymes involved in the biogeochemical cycles of carbon, nitrogen, phosphorous and sulphur, respectively, as well as microbial biomass C were measured. Results of this study seem to indicate that a great variability exists among the farms. A clear evidence is that the control samples, not subjected to intensive farming, always showed better values of chemical properties and higher values of enzymatic activity and microbial biomass to indicate a negative effect of intensive agriculture practices on soil quality and fertility in studied areas. Data confirm that enzymatic activities and microbial biomass can be considered valid and sensitive indicators of soil quality.

Scotti, R.; D'Ascoli, R.; Rao, M. A.; Marzaioli, R.; Rutigliano, F. A.; Gianfreda, L.

2009-04-01

62

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

63

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

E-print Network

Summary Soil respiration is controlled by soil temperature, soil water, fine roots, microbial content, and root density and activity, and thus changes soil respiration. We measured soil respiration (after thinning). Thinning increased the spatial homogeneity of soil temperature and respiration. We

Cohen, Ronald C.

64

Diversity and Activity of Denitrifiers of Chilean Arid Soil Ecosystems  

PubMed Central

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

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

2012-01-01

65

Molecular Biology Concepts and Activities  

NSDL National Science Digital Library

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

Waldron, Ingrid

66

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

67

Effects of transgenic Bt cotton on soil fertility and biology under field conditions in subtropical inceptisol.  

PubMed

Although there is large-scale adoption of Bt cotton by the farmers because of immediate financial gain, there is concern that Bt crops release Bt toxins into the soil environment which reduces soil chemical and biological activities. However, the majorities of such studies were mainly performed under pot experiments, relatively little research has examined the direct and indirect effects of associated cover crop of peanut with fertilization by combined application of organic and inorganic sources of nitrogen under field conditions. We compared soil chemical and biological parameters of Bt cotton with pure crop of peanut to arrive on a valid conclusion. Significantly higher dehydrogenase enzyme activity and KMnO(4)-N content of soil were observed in Bt cotton with cover crop of peanut over pure Bt cotton followed by pure peanut at all the crop growth stages. However, higher microbial population was maintained by pure peanut over intercropped Bt cotton, but these differences were related to the presence of high amount of KMnO(4)-N content of soil. By growing cover crop of peanut between Bt cotton rows, bacteria, fungi, and actinomycetes population increased by 60%, 14%, and 10%, respectively, over Bt cotton alone. Bt cotton fertilized by combined application of urea and farm yard manure (FYM) maintained higher dehydrogenase enzyme activity, KMnO(4)-N content of soil and microbial population over urea alone. Significant positive correlations were observed for dry matter accumulation, dehydrogenase enzyme activity, KMnO(4)-N content, and microbial population of soil of Bt cotton, which indicates no harmful effects of Bt cotton on soil biological parameters and associated cover crop. Our results suggest that inclusion of cover crop of peanut and FYM in Bt cotton enhanced soil chemical and biological parameters which can mask any negative effect of the Bt toxin on microbial activity and thus on enzymatic activities. PMID:22350447

Singh, Raman Jeet; Ahlawat, I P S; Singh, Surender

2013-01-01

68

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

69

Mind the gap: non-biological processes contributing to soil CO2 efflux.  

PubMed

Widespread recognition of the importance of soil CO2 efflux as a major source of CO2 to the atmosphere has led to active research. A large soil respiration database and recent reviews have compiled data, methods, and current challenges. This paper highlights some deficiencies for a proper understanding of soil CO2 efflux focusing on processes of soil CO2 production and transport that have not received enough attention in the current soil respiration literature. It has mostly been assumed that soil CO2 efflux is the result of biological processes (i.e. soil respiration) but recent studies demonstrate that pedochemical and geological processes, such as geothermal and volcanic CO2 degassing, are potentially important in some areas. Besides the microbial decomposition of litter, solar radiation is responsible for photodegradation or photochemical degradation of litter. Diffusion is considered to be the main mechanism of CO2 transport in the soil, but changes in atmospheric pressure and thermal convection may also be important mechanisms driving soil CO2 efflux greater than diffusion under certain conditions. Lateral fluxes of carbon as dissolved organic and inorganic carbon occur and may cause an underestimation of soil CO2 efflux. Traditionally soil CO2 efflux has been measured with accumulation chambers assuming that the main transport mechanism is diffusion. New techniques are available such as improved automated chambers, CO2 concentration profiles and isotopic techniques that may help to elucidate the sources of carbon from soils. We need to develop specific and standardised methods for different CO2 sources to quantify this flux on a global scale. Biogeochemical models should include biological and non-biological CO2 production processes before we can predict the response of soil CO2 efflux to climate change. Improving our understanding of the processes involved in soil CO2 efflux should be a research priority given the importance of this flux in the global carbon budget. This article is protected by copyright. All rights reserved. PMID:25471988

Rey, Ana

2014-12-01

70

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

71

Diverse biological activities of dandelion.  

PubMed

Dandelion (Taraxacum officinale Weber) is a member of the Asteraceae (Compositae) family, native to Europe but widely distributed in the warmer temperate zones of the Northern Hemisphere. Dandelion and its parts are habitually consumed as plant foods in several areas of the world, where they are also employed in phytotherapy. Indeed, dandelion contains a wide array of phytochemicals whose biological activities are actively being explored in various areas of human health. In particular, emerging evidence suggests that dandelion and its constituents have antioxidant and anti-inflammatory activities that result in diverse biological effects. The present review provides a comprehensive analysis of the constituents of dandelion, an assessment of the pharmacological properties of dandelion, and a description of relevant studies that support the use of dandelion as a medicinal plant. PMID:22946853

González-Castejón, Marta; Visioli, Francesco; Rodriguez-Casado, Arantxa

2012-09-01

72

Biological Soil Crusts and Wind Erosion  

Microsoft Academic Search

\\u000a Wind is an important erosive force in deserts, where limited cover of vascular plant material offers little soil-surface protection.\\u000a Dust deposition by wind often exceeds that of fluvial deposition in these drier regions (Goudie 1978; Williams et al. 1995). Sediment production from soil surfaces occurs when wind forces exceed soil threshold friction velocities (TFV: the wind\\u000a velocity needed to detach

J. Belnap

73

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

NASA Astrophysics Data System (ADS)

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

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

2010-08-01

74

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

75

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

76

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

77

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

78

Ice Nucleation Activity in the Widespread Soil Fungus Mortierella alpina  

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

79

County-Scale Spatial Distribution of Soil Enzyme Activities and Enzyme Activity Indices in Agricultural Land: Implications for Soil Quality Assessment  

PubMed Central

Here the spatial distribution of soil enzymatic properties in agricultural land was evaluated on a county-wide (567?km2) scale in Changwu, Shaanxi Province, China. The spatial variations in activities of five hydrolytic enzymes were examined using geostatistical methods. The relationships between soil enzyme activities and other soil properties were evaluated using both an integrated total enzyme activity index (TEI) and the geometric mean of enzyme activities (GME). At the county scale, soil invertase, phosphatase, and catalase activities were moderately spatially correlated, whereas urease and dehydrogenase activities were weakly spatially correlated. Correlation analysis showed that both TEI and GME were better correlated with selected soil physicochemical properties than single enzyme activities. Multivariate regression analysis showed that soil OM content had the strongest positive effect while soil pH had a negative effect on the two enzyme activity indices. In addition, total phosphorous content had a positive effect on TEI and GME in orchard soils, whereas alkali-hydrolyzable nitrogen and available potassium contents, respectively, had negative and positive effects on these two enzyme indices in cropland soils. The results indicate that land use changes strongly affect soil enzyme activities in agricultural land, where TEI provides a sensitive biological indicator for soil quality. PMID:25610908

Xie, Baoni; Wang, Junxing; He, Wenxiang; Wang, Xudong; Wei, Gehong

2014-01-01

80

Environmental implications of herbicide resistance: soil biology and ecology  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil microbial community structure and activity are clearly linked to plant communities established in natural and agricultural ecosystems. A limited number of studies confirm that weeds alter their soil environment and select for specific microbial communities in the rhizosphere. Such rhizosphere m...

81

Soil Biology & Biochemistry 38 (2006) 35063510 Short communication  

E-print Network

Soil Biology & Biochemistry 38 (2006) 3506­3510 Short communication Simultaneous inhibition of CH4 by dissimilatory SO4 2� reducing bacteria (SRB), lacks supporting evidence. Here, we present data from an acid rain; Wetlands; Emissions; Acid rain; Bacteria; SRB; Methanogens; Bogs; Atmosphere; Competitive exclusion Sulphur

Gauci, Vincent

82

[Changes in the properties of oily gray forest soil during biological reclamation].  

PubMed

Recovery of gray forest soil severely contaminated by separator oil by a biological technique using Bacispecin was demonstrated. Agrophysical, agrichemical, physicochemical, and biological properties of the soil were restored in the plough layer during the reclamation. PMID:15768640

Sule?manov, R R; Gabbasova, I M; Sitdikov, R N

2005-01-01

83

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

E-print Network

desert, climate change, Colorado Plateau, environmental stress, soil fauna, soil food websEffects of Altered Temperature and Precipitation on Desert Protozoa Associated with Biological Soil with cyanobacteria crusts alone. Amoebae, flagellates, and ciliates originating from the Colorado Plateau desert

Neher, Deborah A.

84

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

85

Influence of Biological Soil Crust and Litter on Bromus Tectorum Establishment Under Natural Conditions  

Microsoft Academic Search

Previous experiments under growth chamber conditions indicated that a biological soil crust dominated by the moss Bryum argenteum decreased the establishment of the invasive weed Bromus tectorum (cheatgrass). We are presently studying whether a similar phenomenon occurs in a natural setting. For this purpose, we prepared trays with bare soil and soil covered with biological soil and distributed B. tectorum

Tyler Osgood

2009-01-01

86

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

87

Soil Biology & Biochemistry 38 (2006) 30653082 Soil carbon turnover in the McMurdo Dry Valleys, Antarctica  

E-print Network

Soil Biology & Biochemistry 38 (2006) 3065­3082 Soil carbon turnover in the McMurdo Dry Valleys Valleys are among the most inhospitable soil environments on Earth due to climate and substrate because likely sources of organic matter are 102 ­104 yrs old and in situ soil respiration is typically

Wall, Diana

88

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

Microsoft Academic Search

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

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

2010-01-01

89

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

90

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

91

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

E-print Network

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

Jackson, Robert B.

92

Visually assessing the level of development and soil surface stability of cyanobacterially dominated biological soil crusts  

USGS Publications Warehouse

Biological soil crusts (BSCs) are an integral part of dryland ecosystems and often included in long-term ecological monitoring programs. Estimating moss and lichen cover is fairly easy and non-destructive, but documenting cyanobacterial level of development (LOD) is more difficult. It requires sample collection for laboratory analysis, which causes soil surface disturbance. Assessing soil surface stability also requires surface disturbance. Here we present a visual technique to assess cyanobacterial LOD and soil surface stability. We define six development levels of cyanobacterially dominated soils based on soil surface darkness. We sampled chlorophyll a concentrations (the most common way of assessing cyanobacterial biomass), exopolysaccharide concentrations, and soil surface aggregate stability from representative areas of each LOD class. We found that, in the laboratory and field, LOD classes were effective at predicting chlorophyll a soil concentrations (R2=68-81%), exopolysaccharide concentrations (R2=71%), and soil aggregate stability (R2=77%). We took representative photos of these classes to construct a field guide. We then tested the ability of field crews to distinguish these classes and found this technique was highly repeatable among observers. We also discuss how to adjust this index for the different types of BSCs found in various dryland regions.

Belnap, J.; Phillips, S.L.; Witwicki, D.L.; Miller, M.E.

2008-01-01

93

Hands-on Activities for Teaching Biology  

NSDL National Science Digital Library

These hands-on, minds-on activities engage students in experiments or simulation activities and incorporate multiple questions designed to foster student understanding of important concepts in the life sciences. Topics covered include biological molecules, diffusion, metabolism, cell division, genetics, molecular biology, evolution, diversity, human physiology and design and interpretation of experiments. These activities were designed for teaching high school or middle school students, but many of these activities can also be used in non-major introductory college biology classes. To accommodate limited budgets, most of these activities can be carried out with minimum equipment and expense for supplies. Additional minds-on activities for teaching biology, including discussion activities, are available at http://serendip.brynmawr.edu/exchange/bioactivities. 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.

Waldron, Ingrid; Doherty, Jennifer

94

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

95

Assessment of soil biological quality index (QBS-ar) in different crop rotation systems in paddy soils  

NASA Astrophysics Data System (ADS)

New methods, based on soil microarthropods for soil quality evaluation have been proposed by some Authors. Soil microarthropods demonstrated to respond sensitively to land management practices and to be correlated with beneficial soil functions. QBS Index (QBS-ar) is calculated on the basis of microarthropod groups present in a soil sample. Each biological form found in the sample receives a score from 1 to 20 (eco-morphological index, EMI), according to its adaptation to soil environment. The objective of this study was to evaluate the effect of various rotation systems and sampling periods on soil biological quality index, in paddy soils. For the purpose of this study surface soil samples (0-15 cm depth) were collected from different rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) with three replications, and four sampling times in April (after field preparation), June (after seedling), August (after tillering stage) and October (after rice harvesting). The study area is located in paddy soils of Verona area, Northern Italy. Soil microarthropods from a total of 48 samples were extracted and classified according to the Biological Quality of Soil Index (QBS-ar) method. In addition soil moisture, Cumulative Soil Respiration and pH were measured in each site. More diversity of microarthropod groups was found in June and August sampling times. T-test results between different rotations did not show significant differences while the mean difference between rotation and different sampling times is statistically different. The highest QBS-ar value was found in the fallow-rice rotation in the forth soil sampling time. Similar value was found in soya-rice-rice rotation. Result of linear regression analysis indicated that there is significant correlation between QBS-ar values and Cumulative Soil Respiration. Keywords: soil biological quality index (QBS-ar), Crop Rotation System, paddy soils, Italy

Nadimi-Goki, Mandana; Bini, Claudio; haefele, Stephan

2013-04-01

96

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

97

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

USGS Publications Warehouse

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

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

2011-01-01

98

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

PubMed

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

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

2014-12-01

99

Minds-On Activities for Teaching Biology  

NSDL National Science Digital Library

These minds-on activities include analysis and discussion 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 and middle school students, but many of them can also be used 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.

Ingrid Waldron

100

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

101

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

E-print Network

1 Soil drainage as an active agent of recent soil evolution: a review* David Montagnea,b , Sophie on pedogenesis mainly focuses on the long-term soil formation and most often neglects recent soil evolution drainage on soil evolution. Artificial drainage is considered as an example of the impact of recent changes

Boyer, Edmond

102

The effect of model soil contamination with Cr, Cu, Ni, and Pb on the biological properties of soils in the dry steppe and semidesert regions of southern Russia  

NASA Astrophysics Data System (ADS)

Model soil contamination with Cr, Cu, Ni, and Pb in the dry steppes and semideserts of southern Russia has worsened the biological soil properties. With respect to the degree of deterioration of the biological properties, the soils can be arranged in the following sequence: dark chestnut soils > chestnut soils > light chestnut soils > brown semidesert soils > sandy brown semidesert soils. The sequence of metal oxides according to the adverse effect on the biological soil properties is as follows: CrO3 > CuO ? PbO ? NiO.

Kolesnikov, S. I.; Spivakova, N. A.; Kazeev, K. Sh.

2011-09-01

103

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

104

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

105

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.

106

Impacts of off-road vehicles on nitrogen cycles in biological soil crusts: Resistance in different U.S. deserts  

USGS Publications Warehouse

Biological soil crusts are an important component of desert ecosystems, as they influence soil stability and fertility. This study examined and compared the short-term vehicular impacts on lichen cover and nitrogenase activity (NA) of biological soil crusts. Experimental disturbance was applied to different types of soil in regions throughout the western U.S. (Great Basin, Colorado Plateau, Sonoran, Chihuahuan, and Mojave deserts). Results show that pre-disturbance cover of soil lichens is significantly correlated with the silt content of soils, and negatively correlated with sand and clay. While disturbance appeared to reduce NA at all sites, differences were statistically significant at only 12 of the 26 sites. Cool desert sites showed a greater decline than hot desert sites, which may indicate non-heterocystic cyanobacterial species are more susceptible to disturbance than non-heterocystic species. Sandy soils showed greater reduction of NA as sand content increased, while fine-textured soils showed a greater decline as sand content increased. At all sites, higher NA before the disturbance resulted in less impact to NA post-disturbance. These results may be useful in predicting the impacts of off-road vehicles in different regions and different soils. ?? 2002 Published by Elsevier Science Ltd.

Belnap, J.

2002-01-01

107

Improved appreciation of the functioning and importance of biological soil crusts in Europe: the Soil Crust International Project (SCIN).  

PubMed

Here we report details of the European research initiative "Soil Crust International" (SCIN) focusing on the biodiversity of biological soil crusts (BSC, composed of bacteria, algae, lichens, and bryophytes) and on functional aspects in their specific environment. Known as the so-called "colored soil lichen community" (Bunte Erdflechtengesellschaft), these BSCs occur all over Europe, extending into subtropical and arid regions. Our goal is to study the uniqueness of these BSCs on the regional scale and investigate how this community can cope with large macroclimatic differences. One of the major aims of this project is to develop biodiversity conservation and sustainable management strategies for European BSCs. To achieve this, we established a latitudinal transect from the Great Alvar of Öland, Sweden in the north over Gössenheim, Central Germany and Hochtor in the Hohe Tauern National Park, Austria down to the badlands of Tabernas, Spain in the south. The transect stretches over 20° latitude and 2,300 m in altitude, including natural (Hochtor, Tabernas) and semi-natural sites that require maintenance such as by grazing activities (Öland, Gössenheim). At all four sites BSC coverage exceeded 30 % of the referring landscape, with the alpine site (Hochtor) reaching the highest cyanobacterial cover and the two semi-natural sites (Öland, Gössenheim) the highest bryophyte cover. Although BSCs of the four European sites share a common set of bacteria, algae (including cyanobacteria) lichens and bryophytes, first results indicate not only climate specific additions of species, but also genetic/phenotypic uniqueness of species between the four sites. While macroclimatic conditions are rather different, microclimatic conditions and partly soil properties seem fairly homogeneous between the four sites, with the exception of water availability. Continuous activity monitoring of photosystem II revealed the BSCs of the Spanish site as the least active in terms of photosynthetic active periods. PMID:24954978

Büdel, Burkhard; Colesie, Claudia; Green, T G Allan; Grube, Martin; Lázaro Suau, Roberto; Loewen-Schneider, Katharina; Maier, Stefanie; Peer, Thomas; Pintado, Ana; Raggio, José; Ruprecht, Ulrike; Sancho, Leopoldo G; Schroeter, Burkhard; Türk, Roman; Weber, Bettina; Wedin, Mats; Westberg, Martin; Williams, Laura; Zheng, Lingjuan

2014-01-01

108

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

PubMed Central

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

Uz, Ilker; Tavali, Ismail Emrah

2014-01-01

109

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

PubMed

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

Uz, Ilker; Tavali, Ismail Emrah

2014-01-01

110

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

PubMed Central

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

111

Biological activity of rhizobial siderophore.  

PubMed

Non-nodulating mutant of Rhizobium leguminosarum biovar trifolli produces the phenolate type of siderophore consisting of 2,3-dihydroxybenzoic acid and threonine. The activity of this compound against the various bacteria was tested. Only, the growth of R. leguminosarum strains was stimulated by siderophore. The other species of Rhizobium, especially R. meliloti, were sensitive to this agent. The growth of R. meliloti was also inhibited by agrobactin and pseudobactin. This effect was reversed by ferric iron. PMID:1726625

Dery?o, M; Skorupska, A

1991-01-01

112

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

113

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. PMID:23216850

2012-01-01

114

[Yersinia lipopolysaccharide and its biological activity].  

PubMed

The data on the structure and biological activity of the lipopolysaccharide (LPS) of Yersinia as an important virulence factor are analyzed. The biological effects of LPS are characterized by dose dependence: small doses stimulate the intensity of phagocytosis, while large doses decrease phagocytic activity and produce cytotoxic effect. Yersinia LPS plays an important role in the development of such consequences of yersiniosis as reactive arthritis, erythema nodosum, Reiter's syndrome. Yersinia LPS is a widespread component for the diagnostics of yersiniosis and pseudotuberculosis. PMID:16830602

Svarval', A V; Tseneva, G Ia; Shenderovich, O A

2006-01-01

115

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

116

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

E-print Network

genera in deserts soils and their functional role in a crust-associated food web. # 2006 Elsevier B Plateau, Utah (cool, winter rain desert) and Chihuahuan Desert, New Mexico (hot, summer rain desert) at 0­belowground link between biological soil crusts and nematode community composition is likely the increased food

Neher, Deborah A.

117

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

118

Preferential flow paths: biological ‘hot spots’ in soils  

Microsoft Academic Search

Preferential flow of water in soils is a common phenomenon. Our objective was to investigate whether preferential flow paths have higher microbial biomass and different microbial community structures than the rest of the soil. We stained the preferential flow paths in a forest soil with a food dye and sampled soil material from preferential flow paths and from the soil

M. Bundt; F. Widmer; M. Pesaro; J. Zeyer; P. Blaser

2001-01-01

119

Effects of validamycin on some enzymatic activities in soil  

Microsoft Academic Search

There have been few investigations of the possible effects of validamycin on the enzymatic activities in soil. The objective\\u000a of this present work was to study the short-term influence of enzymatic activity in validamycin treated soils. The results\\u000a showed that high dose of validamycin introduced into soil had an significant effect on soil enzymatic activities, the degree\\u000a of inhibition or

Haifeng Qian; Baolan Hu; Zhiye Wang; Xi Xu; Tao Hong

2007-01-01

120

Aluminum in seawater: control by biological activity.  

PubMed

The distribution and concentration of dissolved aluminum in a vertical hydrographic profile in the Mediterranean Sea near Corsica are controlled by biological activity. The concentrations of dissolved silica and aluminum covary in the profile and exhibit minima coincident with the seasonal thermocline, a nitrate minimum, and an oxygen maximum. These observations support the hypothesis that the silicon and aluminum cycles in the oceans are linked through the activity of diatoms. PMID:17788117

Mackenzie, F T; Stoffyn, M; Wollast, R

1978-02-10

121

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

122

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

PubMed Central

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

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

2012-01-01

123

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

124

Activated Peroxygens for Remediation of Contaminated Soil and Groundwater  

E-print Network

i Activated Peroxygens for Remediation of Contaminated Soil and Groundwater Ph.D. thesis Submitted May 2011 #12;ii Activated Peroxygens for Remediation of Contaminated Soil and Groundwater Ph.D. thesis peroxygens for remediation of contaminated soil and groundwater" along with 5 papers describing part

Hansen, René Rydhof

125

Loranthus micranthus Linn.: Biological Activities and Phytochemistry  

PubMed Central

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

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

2013-01-01

126

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

127

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

128

Soil microbial activity and structure in mineralized terranes of the Western US  

NASA Astrophysics Data System (ADS)

Mineralized terranes (areas enriched in metal-bearing minerals) occur throughout the Western US, and are characterized by highly variable soil trace metal concentrations across small spatial scales. Assuming that non-lithologic (extrinsic) soil forming factors are relatively constant between mineralized and unmineralized zones, these mineralized areas allowed us to evaluate the effect of lithology on soil microbial activity. We established the following study sites: 1) sage-grassland on a Mo/Cu deposit (Battle Mountain, NV); 2) pine-chaparral on Ni/Cr bearing rocks (Chinese Camp, CA); and 3) two pine woodland sites on acid-sulfate altered rocks (Reno, NV; Bridgeport, CA). Microbial, physical and chemical measurements were performed on soils from undisturbed mineralized areas and adjacent unmineralized areas to determine baseline conditions for comparison to sites disturbed by mining. A host of abiotic soil parameters, along with bioavailable (diethylenetriaminepentaacetic acid (DTPA)-extractable) and total metals, were measured to examine their correlation with the following measures of microbial activity: enzyme assays (arylsulfatase, phosphatase, fluorescein diacetate hydrolysis), C/N mineralization potential, C substrate utilization (Biolog Ecoplate), and microbial biomass and community structure (phospholipid fatty acid analysis). Within the Battle Mountain study area, both microbial activity and structure were statistically similar between mineralized and unmineralized soils. Nutrient and metal concentrations were also similar; the only differences being higher Cu and lower P in the mineralized soils. Within the Chinese Camp study area, soil organic carbon and total nitrogen concentrations were similar between the serpentine (Ni/Cr bearing) and adjacent andesite soils, while differences were noted for other nutrients (S, P, Ca, Mg). For the serpentine soils, Co, Fe, Mn, and Ni showed the strongest correlations with microbial activity, where Cr, Mn showed the strongest correlations in the andesite soils. Measures of microbial activity were statistically similar, except for arylsulfatase and Biolog C substrate utilization, which were greater in the andesite soils. Biolog substrate utilization richness was greater for the andesite soils, which also showed greater fungal biomass compared to the serpentine soils. In the acid sulfate systems, most measures of microbial activity were reduced in the acid sulfate soils compared to the adjacent andesite soils. Lower pH and P, and greater Al concentrations in the acid sulfate soils are potential inhibitors of microbial activity, while greater concentrations of inorganic N suggest that N is not limiting in the acid sulfate soils. Biolog substrate utilization richness was much lower in the acid sulfate soils, which also exhibited a greater proportion of polymer and carbohydrate use compared to the andesite soils. Impacts on microbial activity and microbial community structure are depend on a combination of trace metal and nutrient concentrations within a given mineralization type. Improving our understanding of biotic/abiotic relationships in undisturbed systems should increase our understanding of these relationships in areas disturbed by mining.

Blecker, S. W.; Stillings, L. L.; Decrappeo, N.; Ippolito, J.

2009-12-01

129

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

NASA Astrophysics Data System (ADS)

While radiocarbon (14C) abundances in standing stocks of soil carbon have 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, however, are often temporally sparse 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 ?14CO2 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 respired ?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 declines in the 14C content of soil respiration over the growing season, and suggest inputs of new photosynthates through roots are an important driver.

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

2013-12-01

130

Measuring Myeloperoxidase Activity in Biological Samples  

PubMed Central

Background Enzymatic activity measurements of the highly oxidative enzyme myeloperoxidase (MPO), which is implicated in many diseases, are widely used in the literature, but often suffer from nonspecificity and lack of uniformity. Thus, validation and standardization are needed to establish a robust method that is highly specific, sensitive, and reproducible for assaying MPO activity in biological samples. Principal findings We found conflicting results between in vivo molecular MR imaging of MPO, which measures extracellular activity, and commonly used in vitro MPO activity assays. Thus, we established and validated a protocol to obtain extra- and intracellular MPO from murine organs. To validate the MPO activity assays, three different classes of MPO activity assays were used in spike and recovery experiments. However, these assay methods yielded inconsistent results, likely because of interfering substances and other peroxidases present in tissue extracts. To circumvent this, we first captured MPO with an antibody. The MPO activity of the resultant samples was assessed by ADHP and validated against samples from MPO-knockout mice in murine disease models of multiple sclerosis, steatohepatitis, and myocardial infarction. We found the measurements performed using this protocol to be highly specific and reproducible, and when performed using ADHP, to be highly sensitive over a broad range. In addition, we found that intracellular MPO activity correlated well with tissue neutrophil content, and can be used as a marker to assess neutrophil infiltration in the tissue. Conclusion We validated a highly specific and sensitive assay protocol that should be used as the standard method for all MPO activity assays in biological samples. We also established a method to obtain extra- and intracellular MPO from murine organs. Extracellular MPO activity gives an estimate of the oxidative stress in inflammatory diseases, while intracellular MPO activity correlates well with tissue neutrophil content. A detailed step-by-step protocol is provided. PMID:23861842

Forghani, Reza; Schob, Stefan; Hsieh, Kevin L. C.; Wojtkiewicz, Gregory; Linnoila, Jenny J.; Chen, John W.

2013-01-01

131

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

132

Vulnerability of desert biological soil crusts to wind erosion: The influences of crust development, soil texture, and disturbance  

USGS Publications Warehouse

Biological soil crusts, consisting of cyanobacteria, green algae, lichens, and mosses, are important in stabilizing soils in semi-arid and arid lands. Integrity of these crusts is compromised by compressional disturbances such as foot, vehicle, or livestock traffic. Using a portable wind tunnel, we found threshold friction velocities (TFVs) of undisturbed crusts well above wind forces experienced at these sites; consequently, these soils are not vulnerable to wind erosion. However, recently disturbed soils or soils with less well-developed crusts frequently experience wind speeds that exceed the stability thresholds of the crusts. Crustal biomass is concentrated in the top 3 mm of soils. Sandblasting by wind can quickly remove this material, thereby reducing N and C inputs from these organisms. This loss can result in reduced site productivity, as well as exposure of unprotected subsurface sediments to wind and water erosion. Actions to reduce impacts to these crusts can include adjustments in type, intensity, and timing of use.

Belnap, J.; Gillette, D.A.

1998-01-01

133

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

134

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

PubMed Central

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

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

2014-01-01

135

Simple flavones possessing complex biological activity  

Microsoft Academic Search

Two simple flavones, each of which exhibits distinct biological activity despite their closely related structures, have been recognized by detailed bioassays, and bioassay-orientated isolation procedures. The identity of both flavones has been confirmed by synthesis. One of these compounds, 5-methoxy-6,7-methylenedioxyflavone has been found in an extract of Polygonum lapathifolium L. subsp. nodosum (Polygonaceae) using a screening test devised to detect

S. Tahara; J. L. Ingham

2000-01-01

136

Generation and Biological Activities of Oxidized Phospholipids  

PubMed Central

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

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

2010-01-01

137

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

138

A microcosm approach to assessing the effects of earthworm inoculation and oat cover cropping on CO2 fluxes and biological properties in an amended semiarid soil.  

PubMed

We designed a microcosm experiment to assess the influence of inoculation with Eisenia foetida earthworms and the establishment of an Avena sativa cover crop on biological (enzyme activities and labile carbon fractions) soil quality indicators in a soil treated with a composted organic residue, and to determine the contribution of these treatments to carbon dioxide emissions from the soil to the atmosphere of the microcosm. The microcosms were incubated for 53 days under 28 degrees C/18 degrees C day/night temperatures. The addition of earthworms and the planting of A. sativa increased dehydrogenase activity of compost amended soil by about 44% after 23 days of incubation. The metabolic potential, calculated as the ratio dehydrogenase activity/water soluble C, was higher in the compost amended soil planted with A. sativa. The highest total amount of CO2-C evolved occurred in the soil treated with composted residue and earthworms (about 40% of the total amount of CO2 evolved came from earthworm activity). The planting of A. sativa increased the decomposition rate constant of organic matter in the amended soil but decreased the potentially mineralizable C pool. In conclusion, the establishment of an A. sativa cover crop and the addition of E. foetida to a degraded agricultural soil treated with composted residue were effective treatments for improving the biological and biochemical quality and the metabolic potential of the soil. PMID:15894048

Caravaca, F; Pera, A; Masciandaro, G; Ceccanti, B; Roldán, A

2005-06-01

139

Physicochemical and biological quality of soil in hexavalent chromium-contaminated soils as affected by chemical and microbial remediation.  

PubMed

Chemical and microbial methods are the main remediation technologies for chromium-contaminated soil. These technologies have progressed rapidly in recent years; however, there is still a lack of methods for evaluating the chemical and biological quality of soil after different remediation technologies have been applied. In this paper, microbial remediation with indigenous bacteria and chemical remediation with ferrous sulphate were used for the remediation of soils contaminated with Cr(VI) at two levels (80 and 1,276 mg kg(-1)) through a column leaching experiment. After microbial remediation with indigenous bacteria, the average concentration of water-soluble Cr(VI) in the soils was reduced to less than 5.0 mg kg(-1). Soil quality was evaluated based on 11 soil properties and the fuzzy comprehensive assessment method, including fuzzy mathematics and correlative analysis. The chemical fertility quality index was improved by one grade using microbial remediation with indigenous bacteria, and the biological fertility quality index increased by at least a factor of 6. Chemical remediation with ferrous sulphate, however, resulted in lower levels of available phosphorus, dehydrogenase, catalase and polyphenol oxidase. The result showed that microbial remediation with indigenous bacteria was more effective for remedying Cr(VI)-contaminated soils with high pH value than chemical remediation with ferrous sulphate. In addition, the fuzzy comprehensive evaluation method was proven to be a useful tool for monitoring the quality change in chromium-contaminated soils. PMID:23784058

Liao, Yingping; Min, Xiaobo; Yang, Zhihui; Chai, Liyuan; Zhang, Shujuan; Wang, Yangyang

2014-01-01

140

Mercury speciation and effects on soil microbial activities.  

PubMed

To study Hg toxicity on soil microbes and their activities, it is necessary to understand its various forms in soils. The objectives of this study were to investigate Hg speciation in four soil types spiked with Hg (300 mg kg(-1) soil) and its effects on soil microbial respiration and enzymes (amidohydrolases and phosphatase) activities. An assessment of the chemical forms, amounts, reactions, and mobility of Hg in soils and sediments is of significant importance to improve and maintain soil and environmental health and sustainability. Mercury speciation analysis was investigated under acidic and alkaline conditions using a modified sequential procedure, which differentiates Hg into the four distinct fractions. Soil microbial respiration and enzymes activities were determined under laboratory settings, by incubating the soils at 25°C for 30 days, and then determining the amount of CO(2) evolved. Speciation results revealed that the water soluble form was the least, with < 1% of the total Hg in the soil types investigated irrespective of the pH condition, while the residual fraction was the most abundant (> 80%) in Canisteo, Houston, and Ketona soils under acidic conditions and < 35% in Decatur soil. Under alkaline conditions, the residual fraction was ? 70% in Canisteo, Houston, and ketona and ? 29% in Decatur soil. The exchangeable fraction was the second most abundant fraction in the soils used ranging from 3.7-50.0% under acid conditions and 16.9-52.1% under alkaline conditions indicating that Hg desorption was found to be more favorable under alkaline than acidic conditions. Soil respiration was suppressed by Hg especially at the 100 mg kg(-1) concentration level. Amidohydrolases and phosphatases' response in the presence of Hg was variable. Amidohydrolases were more sensitive to Hg (18-90%) than phosphatase (0-35%) in all soils. This study demonstrated that the forms in which Hg exist in soils may determine its bioavailability and toxicity. Also microbial respiration and enzyme activities are potential bioindicators of heavy metal contamination of the environment. PMID:22423992

Tazisong, Irenus A; Senwo, Zachary N; Williams, Miranda I

2012-01-01

141

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

142

The soil moisture active passive experiments (SMAPEx): Towards soil moisture retrieval from the SMAP mission  

Technology Transfer Automated Retrieval System (TEKTRAN)

NASA’s Soil Moisture Active Passive (SMAP) mission, scheduled for launch in 2014, will carry the first combined L-band radar and radiometer system with the objective of mapping near surface soil moisture and freeze/thaw state globally at near-daily time step (2-3 days). SMAP will provide three soil ...

143

Nonclassical biological activities of quinolone derivatives.  

PubMed

Quinolones are considered as a big family of multi-faceted drugs; their chemical synthesis is flexible and can be easily adapted to prepare new congeners with rationally devised structures. This is shown by the description of many thousands of derivatives in the literature. Scientists could accurately describe their QSAR, which is essential for effective drug design. This also gave them the chance to discover new and unprecedented activities, which makes quinolones an endless source of hope and enables further development of new clinically useful drugs. Quinolones are among the most common frameworks present in the bioactive molecules that have dominated the market for more than four decades. Since 1962, 4(1H)-quinolone-3-carboxylic acid derivatives are widely used as antibacterial agents. Quinolones have a broad and potent spectrum of activity and are also used as second-line drugs to treat tuberculosis (TB). Recently, quinolones have been reported to display "nonclassical" biological activities, such as antitumor, anti-HIV-1 integrase, anti-HCV-NS3 helicase and -NS5B-polymerase activities. The present review focuses on the structural modifications responsible for the transformation of an antibacterial into an anticancer agent and/or an antiviral agent. Indeed, quinolones' antimicrobial action is distinguishable among antibacterial agents, because they target different type II topoisomerase enzymes. Many derivatives of this family show high activity against bacterial topoisomerases and eukaryotic topoisomerases, and are also toxic to cultured mammalian cells and in vivo tumor models. Moreover, quinolones have shown antiviral activity against HIV and HCV viruses. In this context the quinolones family of drugs seem to link three different biological activities (antibacterial, anticancer, and the antiviral profiles) and the review will also provide an insight into the different mechanisms responsible for these activities among different species. PMID:22365088

Ahmed, Abeer; Daneshtalab, Mohsen

2012-01-01

144

Sensitivity of calorimetric indicators of soil microbial activity  

Microsoft Academic Search

Calorimetry was applied to develop a comparative study between the basal respiration and the degradation of an external carbon source in several soil samples. The main goals were to search for the connection between these reactions in soils and to test the sensitivity of calorimetric indices for the microbial activity. The soil samples were from the Brazilian Amazon and from

N. Barros; M. Gallego; S. Feijóo

2007-01-01

145

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

146

SOIL QUALITY AND CROP Dick Wolkowski  

E-print Network

Soil test and pH "Artificial" drainage Residue management Microbial activity Salts #12;Soil biology. Drainage 2. Crop appearance 7. Soil structure 3. Earthworms 8. Soil pH 4. Erosion 9. Soil test P 5. Tillage SUBJECTIVE: Soil Health? Smell, feel, look, taste? Soil Quality Index MORE QUANTITATIVE Chemical · pH, O

Balser, Teri C.

147

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...

148

Microbial biomass, activity, and community structure in subsurface soils  

Microsoft Academic Search

Microbial biomass, community structure and activity were determined in the subsurface horizons of four contrasting soil types common to Alabama. Biomass and community structure were determined by analyzing the fatty acids of the extractable phospholipids. Activity was estimated by measuring the rate of enzymatic hydrolysis of fluorescein diacetate (FDA). In all four soils, biomass and activity declined with increasing depth;

Thomas W. Federle; Durell C. Dobbins; Janice R. Thornton-Manning; Daniel D. Jones

1986-01-01

149

Soil Quality Information Sheet Rangeland Soil Quality--Soil Biota  

E-print Network

Conservation Service May 2001 Rangeland Sheet 8 What are soil biota? Soil biota, the biologically active, and earthworms), can live in an acre of soil and are more diverse than the community of plants and animals above and earthworms, shred dead leaves and residue, mix them with the soil, and make organic material more accessible

150

Effect of leather industry effluents on soil microbial and protease activity.  

PubMed

Release of leather industry effluents into the agricultural fields causes indicative changes in nutrient cycling and organic matter processing. In the present study, leather industry effluent discharged soil (test) and undischarged soil(control) were collected from the surrounding areas of industry. The physico-chemical, biological properties and soil protease activity were examined. The study reflected the average mean value of pH, electrical conductivity and water holding capacity of the test soil was found to be 7.94, 0.89 microMhos cm(-1) and 0.51 ml g(-1), respectively. In chemical parameters, organic matter, total nitrogen, phosphorus and potassium has the mean of 6.73%, 0.23 g kg(-1), 4.28 mg g(-1) and 28 microg g(-1), respectively. In all the respects, the test soil showed higher values than the control. The soil protease enzyme activity was determined by using substrate casein and the activity was found to be higher (180 microg TE g(-1) 24 hr(-1)) in test soil than the control soil (63 microg TE g(-1) 24 hr(-1)). PMID:23033641

Pradeep, M Reddi; Narasimha, G

2012-01-01

151

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

PubMed Central

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

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

2012-01-01

152

Microbial communities and activities in alpine and subalpine soils.  

PubMed

Soil samples were collected along two slopes (south and north) at subalpine (1500-1900 m, under closed vegetation, up to the forest line) and alpine altitudes (2300-2530, under scattered vegetation, above the forest line) in the Grossglockner mountain area (Austrian central Alps). Soils were analyzed for a number of properties, including physical and chemical soil properties, microbial activity and microbial communities that were investigated using culture-dependent (viable heterotrophic bacteria) and culture-independent methods (phospholipid fatty acid analysis, FISH). Alpine soils were characterized by significantly (P<0.01) colder climate conditions, i.e. lower mean annual air and soil temperatures, more frost and ice days and higher precipitation, compared with subalpine soils. Microbial activity (soil dehydrogenase activity) decreased with altitude; however, dehydrogenase activity was better adapted to cold in alpine soils compared with subalpine soils, as shown by the lower apparent optimum temperature for activity (30 vs. 37 degrees C) and the significantly (P<0.01-0.001) higher relative activity in the low-temperature range. With increasing altitude, i.e. in alpine soils, a significant (P<0.05-0.01) increase in the relative amount of culturable psychrophilic heterotrophic bacteria, in the relative amount of the fungal population and in the relative amount of Gram-negative bacteria was found, which indicates shifts in microbial community composition with altitude. PMID:19049494

Margesin, Rosa; Jud, Melanie; Tscherko, Dagmar; Schinner, Franz

2009-02-01

153

Thiol-derivatized minihepcidins retain biological activity.  

PubMed

Minihepcidins are small peptides that mimic biological activity of the iron-regulatory hormone hepcidin. Structurally, they contain thiol-free-cysteine residue in position 7 which is crucial for their bioactivity. Nonetheless, free sulfhydryl group is not desirable in pharmaceutical entities as it may lead to dermatological side effects. Moreover free thiol moiety is quite reactive and depending on conditions/reagents may be alkylated and/or oxidized giving various Cys-derivatives: S-alkyl cysteines, sulfoxides, sulfones, disulfides, cysteinesulfinic and cysteic acids. To limit such reactivity and maintain bioactivity of minihepcidin(s) we used thiol-protection strategy based on activated vinyl thioethers. Novel S-protected analogs of physiologically active minihepcidin PR73 were synthesized and tested in vitro showing activity comparable to parental molecule. The most active compound, PR73SH was also tested in vivo showing activity profile analogous to PR73. Collectively, our findings suggest that S-vinyl-derivatization of minihepcidin(s) may be a suitable approach in the development of physiologically active agonists of hepcidin. PMID:25599838

Fung, Eileen; Chua, Kristine; Ganz, Tomas; Nemeth, Elizabeta; Ruchala, Piotr

2015-02-15

154

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

155

Regulation of assimilatory nitrate reductase activity in soil by microbial assimilation of ammonium.  

PubMed Central

It is well established that assimilatory nitrate reductase (ANR) activity in soil is inhibited by ammonium (NH4+). To elucidate the mechanism of this inhibition, we studied the effect of L-methionine sulfoximine (MSX), an inhibitor of NH4+ assimilation by microorganisms, on assimilatory reduction of nitrate (NO3-) in aerated soil slurries treated with NH4+. We found that NH4+ strongly inhibited ANR activity in these slurries and that MSX eliminated this inhibition. We also found that MSX induced dissimilatory reduction of NO3- to NH4+ in soil and that the NH4+ thus formed had no effect on the rate of NO-3 reduction. We concluded from these observations that the inhibition of ANR activity by NH4+ is due not to NH4+ per se but to products formed by microbial assimilation of NH4+. This conclusion was supported by a study of the effects of early products of NH4+ assimilation (L amino acids) on ANR activity in soil, because this study showed that the biologically active, L isomers of glutamine and asparagine strongly inhibited ANR activity, whereas the D isomers of these amino acids had little effect on ANR activity. Evidence that ANR activity is regulated by the glutamine formed by NH4+ assimilation was provided by studies showing that inhibitors of glutamine metabolism (azaserine, albizziin, and aminooxyacetate) inhibited ANR activity in soil treated with NO3- but did not do so in the presence of MSX. PMID:11607250

McCarty, G W; Bremner, J M

1992-01-01

156

Biological Activities of Polyphenols from Grapes  

PubMed Central

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

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

2010-01-01

157

Effects of biochar amendments on soil microbial biomass and activity.  

PubMed

Environmental benefits reported in the literature of using biochar as a soil amendment are generally increased microbial activity and reduced greenhouse gas (GHG) emissions. This study determined the effects of amendment with biomass feedstocks (spent coffee grounds, wood pellets, and horse bedding compost) and that of biochars (700°C) produced from these feedstocks on soil microbial biomass (C and N) and activity. Soils were amended with these substrates at 0.75% by weight and incubated for up to 175 d under laboratory conditions. Biochar residual effects on soil microbial activity were also studied by amending these soils with either ammonium nitrate (NHNO, 35 mg N kg) or with glucose (864 mg C kg) plus NHNO. Soil microbial biomass C and N, net N mineralization, and CO, NO, and CH emissions were measured. Amendment with biomass feedstocks significantly increased soil microbial biomass and activity, whereas amendment with the biochars had no significant effect. Also, biochar amendment had no significant effect on either net N mineralization or NO and CH emissions from soil. These results indicate that production of biochars at this high temperature eliminated potential substrates. Microbial biomass C in biochar-amended and unamended soils was not significantly different following additions of NHNO or glucose plus NHNO, suggesting that microbial access to otherwise labile C and N was not affected. This study shows that biochars produced at 700°C, regardless of feedstock source, do not enhance soil microbial biomass or activity. PMID:25602227

Zhang, H; Voroney, R P; Price, G W

2014-11-01

158

Biological and geochemical controls on phosphorus fractions in semiarid soils  

Microsoft Academic Search

This study examined the concentration of organic and inorganicphosphorus in surface soils of a Boutelouagracilis-Bouteloua eriopoda grassland, and a Larreatridentata shrubland, in the northern Chihuahuan Desert, NewMexico, U.S.A. In this desert where the grassland vegetation has auniform spatial distribution and individual shrubs have a patchy spatialdistribution across the landscape, vegetation strongly influences thedistribution of soil nutrients. Most studies of soil

Anne Fernald Cross; William H. Schlesinger

2001-01-01

159

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

PubMed Central

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

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

2012-01-01

160

Agent-based models to address the spatial complexity of biological and physical interactions in soils  

NASA Astrophysics Data System (ADS)

We developed a new computer approach to represent the interactions between soil microorganisms and soil structure in various contexts, namely the decomposition of organic matter by soil bacterial communities, the modification of soil structure due to earthworms dynamics, or phosphorous uptake by myccorhizae in the rhizoshpere. In this presentation, we show how to handle individualized entities evolving in a heterogeneous spatial medium to simulate complex phenomena occurring in soils as the emergence of a set of local behaviours. The consumption of resources by biological organisms can be modelled by an offer versus demand discrete dynamical process. We focus on the effect of spatial organisations on observed phenomena, and we introduce explicit representations of tri-dimensional multiscale soil porous structures. These modelling concepts are illustrated by several applicative examples where simple assumptions about local behavioural rules and medium properties have been made by soil scientists, then implemented and explored.

Beurier, G.; Cambier, C.; Marilleau, N.; Perrier, E.; Duponnois, R.

2009-04-01

161

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

PubMed Central

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

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

2014-01-01

162

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

PubMed Central

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

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

2011-01-01

163

Disturbance of biological soil crusts: impacts on potential wind erodibility of sandy desert soils in southeastern Utah  

Microsoft Academic Search

Friction threshold velocities (FTVs) were determined for biological soil crusts in diÄerent stages of recovery. Particles on the surface of crusts that had been relatively undisturbed for at least 20 years were found to have significantly higher FTVs than those that had been disturbed 5, 10 or 1 years previously (376, 87, and 46 cm sec?1, respectively). FTV's for crust

J. Belnap; D. A. Gillette

1997-01-01

164

Spectroscopic study of biologically active glasses  

NASA Astrophysics Data System (ADS)

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

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

2005-06-01

165

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

166

Bioremediation of oil refinery sludge by landfarming in semiarid conditions: influence on soil microbial activity.  

PubMed

Bioremediation of a refinery sludge containing hydrocarbons in a semi-arid climate using landfarming techniques is described. The objective of this study was to assess the ability of this technique to reduce the total hydrocarbon content added to the soil with the refinery sludge in semiarid climate (low rain and high temperature). In addition, we have evaluated the effect of this technique on the microbial activity of the soil involved. For this, biological parameters (carbon fractions, microbial biomass carbon, basal respiration and ATP) and biochemical parameters(different enzymatic activities) were determined. The results showed that 80% of the hydrocarbons were eliminated in eleven months, half of this reduction taking place during the first three months. The labile carbon fractions, MBC, basal respiration and ATP of the soils submitted to landfarming showed higher values than the control soil during the first months of the process, although these values fell down by the end of the experimental period as the hydrocarbons were degraded by mineralisation. All the enzymatic activities studied: oxidoreductases such as dehydrogenase activity, and hydrolases of C(beta-glucosidase activity) and N Cycle (urease and protease) showed higher values in the soils amended with the refinery sludge than in the control. As in the case of the previous parameters, these value fell down as the bioremediation of the hydrocarbons progressed, many of them reaching levels similar to those of the control soil after eleven months. PMID:15820724

Marin, J A; Hernandez, T; Garcia, C

2005-06-01

167

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

SciTech Connect

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

Smith, E.D.

1995-12-01

168

Biologically active sphingolipids in cancer pathogenesis and treatment  

Microsoft Academic Search

Biologically active sphingolipids have key roles in the regulation of several fundamental biological processes that are integral to cancer pathogenesis. Recent significant progress in understanding biologically active sphingolipid synthesis, specifically within ceramide and sphingosine-1-phosphate (S1P)-mediated pathways, has identified crucial roles for these molecules both in cancer development and progression. Ceramide — a central molecule in sphingolipid metabolism — in effect

Besim Ogretmen; Yusuf A. Hannun

2004-01-01

169

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

170

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

171

Biological activity of a leached chernozem contaminated with the products of combustion of petroleum gas and its restoration upon phytoremediation  

NASA Astrophysics Data System (ADS)

It is shown that contamination of leached chernozems by combustion products of petroleum gas favors changes in the biological activity of the soil: the number of hydrocarbon-oxidizing bacteria and micromycetes has increased, as well as the activity of catalase and lipase and phytotoxicity. Bromopsis inermis Leys used as a phytoameliorant has accelerated the destruction of hydrocarbons in the rhizosphere. The benzpyrene concentration in plants on contaminated soils considerably exceeds its background concentration.

Kireeva, N. A.; Novoselova, E. I.; Shamaeva, A. A.; Grigoriadi, A. S.

2009-04-01

172

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

USGS Publications Warehouse

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

Belnap, Jayne

1996-01-01

173

BIOLOGICAL ACTIVITIES OF C1 INHIBITOR  

PubMed Central

Broadly speaking, C1 inhibitor plays important roles in the regulation of vascular permeability and in the suppression of inflammation. Vascular permeability control is exerted largely through inhibition of two of the proteases involved in the generation of bradykinin, factor XIIa and plasma kallikrein (the plasma kallikrein-kinin system). Anti-inflammatory functions, however, are exerted via several activities including inhibition of complement system proteases (C1r, C1s, MASP2) and the plasma kallikrein-kinin system proteases, in addition to interactions with a number of different proteins, cells and infectious agents. These more recently described, as yet incompletely characterized, activities serve several potential functions, including concentration of C1 inhibitor at sites of inflammation, inhibition of alternative complement pathway activation, inhibition of the biologic activities of gram negative endotoxin, enhancement of bacterial phagocytosis and killing, and suppression of the influx of leukocytes into a site of inflammation. C1 inhibitor has been shown to be therapeutically useful in a variety of animal models of inflammatory diseases, including gram negative bacterial sepsis and endotoxin shock, suppression of hyperacute transplant rejection, and treatment of a variety of ischemia-reperfusion injuries (heart, intestine, skeletal muscle, liver, brain). In humans, early data appear particularly promising in myocardial reperfusion injury. The mechanism (or mechanisms) of the effect of C1 inhibitor in these conditions is (are) not completely clear, but involve inhibition of complement and contact system activation, in addition to variable contributions from other C1 inhibitor activities that do not involve protease inhibition. PMID:18674818

Davis, Alvin E.; Mejia, Pedro; Lu, Fengxin

2008-01-01

174

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

PubMed Central

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

2013-01-01

175

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

PubMed

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

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

2013-01-01

176

Microbial Enzyme Activity and Carbon Cycling in Grassland Soil Fractions  

NASA Astrophysics Data System (ADS)

Extracellular enzymes are necessary to degrade complex organic compounds present in soils. Using physical fractionation procedures, we tested whether old soil carbon is spatially isolated from degradative enzymes across a prairie restoration chronosequence in Illinois, USA. We found that carbon-degrading enzymes were abundant in all soil fractions, including macroaggregates, microaggregates, and the clay fraction, which contains carbon with a mean residence time of ~200 years. The activities of two cellulose-degrading enzymes and a chitin-degrading enzyme were 2-10 times greater in organic matter fractions than in bulk soil, consistent with the rapid turnover of these fractions. Polyphenol oxidase activity was 3 times greater in the clay fraction than in the bulk soil, despite very slow carbon turnover in this fraction. Changes in enzyme activity across the restoration chronosequence were small once adjusted for increases in soil carbon concentration, although polyphenol oxidase activity per unit carbon declined by 50% in native prairie versus cultivated soil. These results are consistent with a `two-pool' model of enzyme and carbon turnover in grassland soils. In light organic matter fractions, enzyme production and carbon turnover both occur rapidly. However, in mineral-dominated fractions, both enzymes and their carbon substrates are immobilized on mineral surfaces, leading to slow turnover. Soil carbon accumulation in the clay fraction and across the prairie restoration chronosequence probably reflects increasing physical isolation of enzymes and substrates on the molecular scale, rather than the micron to millimeter scale.

Allison, S. D.; Jastrow, J. D.

2004-12-01

177

Assessment of genotoxic activity of petroleum hydrocarbon-bioremediated soil  

Microsoft Academic Search

The relationship between toxicity and soil contamination must be understood to develop reliable indicators of environmental restoration for bioremediation. Two bacterial rapid bioassays, SOS chromotest and the umu test with and without metabolic activation (S-9 mixture), were used to evaluate the genotoxicity of petroleum hydrocarbon-contaminated soil following bioremediation treatment. The soil was taken from an engineered biopile at the Czechowice-Dziedzice

Gra?yna P?aza; Grzegorz Na??cz-Jawecki; Krzysztof Ulfig; Robin L. Brigmon

2005-01-01

178

Earthworm activities and the soil system  

Microsoft Academic Search

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

P. Lavelle

1988-01-01

179

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

180

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

181

Warming and drought alter soil phosphatase activity and soil P availability in a Mediterranean shrubland  

Microsoft Academic Search

We conducted a field experiment simulating the warming and drought in a Mediterranean shrubland dominated by Erica multiflora and Globularia alypum with the aim to simulate the next future climate conditions predicted by the IPCC and ecophysiological models. As P is frequently a limiting nutrient in Mediterranean ecosystems, we investigated the drought and warming effects on soil phosphatases activities, soil

J. Sardans; J. Peñuelas; M. Estiarte

2006-01-01

182

Arid soil microbial enzymatic activity profile as affected by geographical location and soil degradation status  

Technology Transfer Automated Retrieval System (TEKTRAN)

Evaluating soil health is critical for any successful remediation effort. Arid lands, with their minimal carbon and water contents, low nutritional status and restricted, seasonal microbial activity pose specific challenges to soil health restoration and by extension, restoration of ecosystem repr...

183

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

184

Effects of some insecticides on microbial activities in sandy soil  

Microsoft Academic Search

Laboratory tests were conducted with 14 insecticides applied to a sandy loam to determine whether these materials caused any effects on microbial activities related to soil fertility. The ammonification of soil native organic nitrogen was not inhibited by any of the insecticide treatments. Some insecticides showed an effect on nitrification during the second week of incubation which subsequently recovered to

C. M. Tu

1994-01-01

185

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

186

ACID RAIN AND SOIL MICROBIAL ACTIVITY: EFFECTS AND THEIR MECHANISMS  

EPA Science Inventory

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

187

The Soil Moisture Active/Passive Mission (SMAP)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Soil Moisture Active/Passive (SMAP) mission will deliver global views of soil moisture content and its freeze/thaw state that are critical terrestrial water cycle state variables. Polarized measurements obtained with a shared antenna L-band radar and radiometer system will allow accurate estima...

188

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

189

Germination and seedling establishment of two annual grasses on lichen-dominated biological soil crusts  

Microsoft Academic Search

Biological soil crusts dominated by lichens are common components of shrub-steppe ecosystems in northwestern US. We conducted\\u000a growth chamber experiments to investigate the effects of these crusts on seed germination and initial seedling establishment\\u000a of two annual grasses; the highly invasive exotic Bromus tectorum L. and the native Vulpia microstachys Nutt. We recorded germination time courses on bare soil and

Lynell Deines; Roger Rosentreter; David J. Eldridge; Marcelo D. Serpe

2007-01-01

190

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

191

Biological Nitrogen Fixation by Native Microorganisms in a Waste-Amended Paddy Soil  

Microsoft Academic Search

Biological nitrogen (N2) fixation (BNF) is an important aspect of sustainable and environmentally-friendly food production and long-term crop productivity. It has been established that free-living N2-fixing microbes and Endophytic bacteria play a vital role in the maintenance of soil fertility in flooded rice culture. The potential use of these microorganisms as a natural biofertilizer under an acidic paddy soil was

H. El-Sharkawi; T. Honna; S. Yamamoto; A. Eneji

2007-01-01

192

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

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

193

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

194

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

PubMed Central

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

Han, Xu; Cheng, Zhihui; Meng, Huanwen

2012-01-01

195

Dynamics of soil organic carbon and microbial activity in treated wastewater irrigated agricultural soils along soil profiles  

NASA Astrophysics Data System (ADS)

Treated wastewater (TWW) is an important source for irrigation water in arid and semiarid regions and already serves as an important water source in Jordan, the Palestinian Territories and Israel. Reclaimed water still contains organic matter (OM) and various compounds that may effect microbial activity and soil quality (Feigin et al. 1991). Natural soil organic carbon (SOC) may be altered by interactions between these compounds and the soil microorganisms. This study evaluates the effects of TWW irrigation on the quality, dynamics and microbial transformations of natural SOC. Priming effects (PE) and SOC mineralization were determined to estimate the influence of TWW irrigation on SOC along soil profiles of agricultural soils in Israel and the Westbank. The used soil material derived from three different sampling sites allocated in Israel and The Palestinian Authority. Soil samples were taken always from TWW irrigated sites and control fields from 6 different depths (0-10, 10-20, 20-30, 30-50, 50-70, 70-100 cm). Soil carbon content and microbiological parameters (microbial biomass, microbial activities and enzyme activities) were investigated. In several sites, subsoils (50-160 cm) from TWW irrigated plots were depleted in soil organic matter with the largest differences occurring in sites with the longest TWW irrigation history. Laboratory incubation experiments with additions of 14C-labelled compounds to the soils showed that microbial activity in freshwater irrigated soils was much more stimulated by sugars or amino acids than in TWW irrigated soils. The lack of such "priming effects" (Hamer & Marschner 2005) in the TWW irrigated soils indicates that here the microorganisms are already operating at their optimal metabolic activity due to the continuous substrate inputs with soluble organic compounds from the TWW. The fact that PE are triggered continuously due to TWW irrigation may result in a decrease of SOC over long term irrigation. Already now this could be detected at some agricultural fields by SOC measurements (Jüschke 2009). Therefore attention has to be drawn especially on the carbon content and quality of the used TWW for irrigation purposes.

Jüschke, Elisabeth; Marschner, Bernd; Chen, Yona; Tarchitzky, Jorge

2010-05-01

196

The biological detoxication of hormone herbicides in soil  

Microsoft Academic Search

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

L. J. Audus

1951-01-01

197

Soil Biology & Biochemistry 38 (2006) 24782480 Short communication  

E-print Network

utilization of the N-heterocyclic herbicides, atrazine and cloransulam-methyl (C-M). Soil depleted by 130 receiving fertilizers. Long-term N deprivation promoted rapid degradation of atrazine and the C-M pyrimidine. Keywords: Atrazine; Cloransulam-methyl; Biodegradation; Nitrogen; Ammonium; Morrow plots; Heterocyclic

Sims, Gerald K.

198

Analytical and statistical approaches to validate biological treatment of petroleum hydrocarbons in soil  

SciTech Connect

A site in southern California, containing 50,000 cubic yards of petroleum contaminated soil, was remediated using land treatment. By using a combination of soil screening and land treatment, the total petroleum hydrocarbon content was reduced to less than the clean-up standard of 1,000 mg/kg. Initial contaminant concentrations ranged between 4,000 and 5,000 mg/kg after screening to remove large globules of tar and pieces of asphalt. Biological treatment time was less than eight months. Simple parametric and nonparametric statistical methods were applied to the results obtained from soil testing. Multiple analytical methods were used to determine the type of residual hydrocarbon and the relative environmental risk associated with the residual contamination. This combination of physical segregation. land treatment, and statistical and analytical methods resulted in soil remediation and permission to use the soil on site without restriction.

Graves, D. [IT Corp., Knoxville, TN (United States); Chase, L. [IT Corp., Wilmington, CA (United States); Ray, J. [Konoike Transport and Engineering, Inc. U.S.A., Wilmington, CA (United States)

1995-09-01

199

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

E-print Network

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

O'Neill, Peggy

200

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...

201

Microbial activities in soils of a former sawmill area.  

PubMed

To find out microbial metabolic functioning and toxicity in a former sawmill area, carbon dioxide evolution, methane oxidation potential, 10 hydrolytic enzyme activities, Vibrio fischeri test, fluorescein diacetate hydrolysis activity (FDA), soil pH, carbon, nitrogen and pentachlorophenol (PCP) content were measured at four sites. The area is contaminated with aged chlorophenols. Chlorophenol content of soil was analyzed with a novel HPLC-MS technique, which allowed to measure chlorophenols without derivatization. The sites had a pollution gradient from 0.5 to 15 microg PCP g dw of soil(-1). Endogenous carbon dioxide evolution, methane oxidation potential, butyrate-esterase, acetate-esterase, sulphatase and aminopeptidase activities were lower at the site 2 than 3, although the site 2 and 3 had similar content of carbon and nitrogen. The soil was toxic in V. fischeri test at the site 2, which had high content of PCP (3.93+/-1.00 microg PCP g dw of soil(-1)). The results indicated that endogenous carbon dioxide evolution, methane oxidation potential, butyrate-esterase, acetate-esterase, sulphatase and aminopeptidase activities were sensitive to PCP in the soil. The results indicated that alpha-glucosidase, beta-glucosidase, beta-xylosidase, beta-cellobiosidase, phosphomonoesterase, N-acetyl-glucosaminidase activity and FDA hydrolysis activity were not sensitive to PCP in the soil. Soil processes involved in the cycling of carbon, nitrogen, sulphur and phosphorus were only slightly vulnerable in the former sawmill area and most sensitive microbial species were probably replaced with more tolerant ones to maintain and recover functioning of the former sawmill soils. PMID:17113624

Kähkönen, Mika A; Tuomela, Marja; Hatakka, Annele

2007-03-01

202

Significance of earthworms in stimulating soil microbial activity  

Microsoft Academic Search

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

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

1998-01-01

203

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

E-print Network

and ecosystem functioning in Victoria Land, Antarctica Since the 1970s, ecological research on the ice and nutritional resources. These ecosystems are taxonomically and functionally simple, thus providing and comprehensively than is normally the case for soils and to link soil species explicitly with ecosystem functioning

Wall, Diana

204

[Effects of understory removal and nitrogen addition on the soil chemical and biological properties of Pinus sylvestris var. mongolica plantation in Keerqin Sandy Land].  

PubMed

A full factorial experiment was conducted to study the effects of understory removal and nitrogen addition (8 g x m(-2)) on the soil NO(3-)-N and NH(4+)-N concentrations, potential net nitrogen mineralization rate (PNM) and nitrification rate (PNN), microbial biomass C (MBC) and N (MBN), MBC/MBN, urease and acid phosphomonoesterase activities, and Olsen-P concentration in a Pinus sylvestris var. mongolica plantation in Keerqin Sandy Land during a growth season. Understory removal decreased the soil NH(4+)-N concentration, PNM, MBC, and MBN/MBN significantly, increased the soil Olsen-P concentration, but had little effects on the soil NO(3-)-N concentration, PNN, and urease and acid phosphomonoesterase activities. Nitrogen addition increased the soil NO(3-)-N concentration, PNM and PNN significantly, but had little effects on the other test properties. The interaction between understory removal and nitrogen addition had significant effects on the soil NH(4+)-N concentration, but little effects on the soil NO(3-)-N concentration. However, the soil NO(3-)-N concentration in the plots of understory removal with nitrogen addition was increased by 27%, compared with the plots of nitrogen addition alone, which might lead to the leaching of NO3-. It was suggested that understory vegetation could play an important role in affecting the soil chemical and biological properties in Mongolian pine plantations, and hence, the importance of understory vegetation should not be neglected when the forest management and restoration were implemented. PMID:22919826

Lin, Gui-Gang; Zhao, Qiong; Zhao, Lei; Li, Hui-Chao; Zeng, De-Hui

2012-05-01

205

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.

206

Fate and activity of microorganisms introduced into soil.  

PubMed Central

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

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

1997-01-01

207

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

208

The Infusion of Environmental Activities into a Secondary Biology Curriculum  

ERIC Educational Resources Information Center

Reviewed are "adventure-type" environmental education activities incorporated into a secondary level biology course. Student wilderness experiences included 24 weekend activities of hiking, bird watching, camping, and cross-country skiing. (SL)

Foster, Helen M.

1976-01-01

209

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...

210

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

211

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

SciTech Connect

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

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

1996-12-31

212

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

NASA Astrophysics Data System (ADS)

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

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

213

Assessment of genotoxic activity of petroleum hydrocarbon-bioremediated soil.  

PubMed

The relationship between toxicity and soil contamination must be understood to develop reliable indicators of environmental restoration for bioremediation. Two bacterial rapid bioassays, SOS chromotest and the umu test with and without metabolic activation (S-9 mixture), were used to evaluate the genotoxicity of petroleum hydrocarbon-contaminated soil following bioremediation treatment. The soil was taken from an engineered biopile at the Czechowice-Dziedzice Polish oil refinery (CZOR). The bioremediation process in the biopile lasted 4 years, and the toxicity measurements were done after this treatment. Carcinogens detected in the soil, polyaromatic hydrocarbons (PAHs), were reduced to low concentrations (2mg/kg dry wt) by the bioremediation process. Genotoxicity was not observed for soils tested with and without metabolic activation by a liver homogenate (S-9 mixture). However, the umu test was more sensitive than the SOS chromotest in the analysis of petroleum hydrocarbon-bioremediated soil. Analytical results of soil used in the bioassays confirmed that the bioremediation process reduced 81% of the petroleum hydrocarbons including PAHs. We conclude that the combined test systems employed in this study are useful tools for the genotoxic examination of remediated petroleum hydrocarbon-contaminated soil. PMID:16216636

P?aza, Grazyna; Na?ecz-Jawecki, Grzegorz; Ulfig, Krzysztof; Brigmon, Robin L

2005-11-01

214

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

215

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

E-print Network

-1 Impacts of biological soil crust disturbance and composition on C and N loss from water erosion Ecology Laboratory, Colorado State University, Fort Collins, CO 80523; 2 USDA ­ ARS Jornada Experimental National Park, Colorado Plateau, Distur- bance, Erosion, Nitrogen, Rainfall simulation, Runoff Abstract

Barger, Nichole

216

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

EPA Science Inventory

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

217

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...

218

Long-term Tillage influences on soil carbon, nitrogen, physical, chemical, and biological properties  

Technology Transfer Automated Retrieval System (TEKTRAN)

Long-term tillage influences physical, chemical, and biological properties of the soil environment and thereby crop production and quality. We evaluated the effect of long-term (>20 yrs) tillage no-till, spring till, and fall plus spring till under continuous spring wheat (Triticum aestivum L.) on s...

219

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

PubMed

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

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

2014-01-01

220

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

Microsoft Academic Search

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

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

2008-01-01

221

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

222

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

223

Agricultural Management Practices And Soil Quality  

E-print Network

Biological Indicators Soil microorganisms (fungi and bacteria) and other fauna (e.g., earthworms, insects. Karlen et al. (1997) proposed the following as vital soil functions: (1) sustaining biological activity the combination of chemical, physical, and biological characteristics that enables soils to perform a wide range

Liskiewicz, Maciej

224

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

PubMed Central

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

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

2009-01-01

225

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

226

Humic fractions of forest, pasture and maize crop soils resulting from microbial activity  

PubMed Central

Humic substances result from the degradation of biopolymers of organic residues in the soil due to microbial activity. The objective of this study was to evaluate the influence of three different ecosystems: forest, pasture and maize crop on the formation of soil humic substances relating to their biological and chemical attributes. Microbial biomass carbon (MBC), microbial respiratory activity, nitrification potential, total organic carbon, soluble carbon, humic and fulvic acid fractions and the rate and degree of humification were determined. Organic carbon and soluble carbon contents decreased in the order: forest > pasture > maize; humic and fulvic acids decreased in the order forest > pasture=maize. The MBC and respiratory activity were not influenced by the ecosystems; however, the nitrification potential was higher in the forest than in other soils. The rate and degree of humification were higher in maize soil indicating greater humification of organic matter in this system. All attributes studied decreased significantly with increasing soil depth, with the exception of the rate and degree of humification. Significant and positive correlations were found between humic and fulvic acids contents with MBC, microbial respiration and nitrification potential, suggesting the microbial influence on the differential formation of humic substances of the different ecosystems. PMID:25477932

Tavares, Rose Luiza Moraes; Nahas, Ely

2014-01-01

227

Activation Energy of Extracellular Enzymes in Soils from Different Biomes  

PubMed Central

Enzyme dynamics are being incorporated into soil carbon cycling models and accurate representation of enzyme kinetics is an important step in predicting belowground nutrient dynamics. A scarce number of studies have measured activation energy (Ea) in soils and fewer studies have measured Ea in arctic and tropical soils, or in subsurface soils. We determined the Ea for four typical lignocellulose degrading enzymes in the A and B horizons of seven soils covering six different soil orders. We also elucidated which soil properties predicted any measurable differences in Ea. ?-glucosidase, cellobiohydrolase, phenol oxidase and peroxidase activities were measured at five temperatures, 4, 21, 30, 40, and 60°C. Ea was calculated using the Arrhenius equation. ?-glucosidase and cellobiohydrolase Ea values for both A and B horizons in this study were similar to previously reported values, however we could not make a direct comparison for B horizon soils because of the lack of data. There was no consistent relationship between hydrolase enzyme Ea and the environmental variables we measured. Phenol oxidase was the only enzyme that had a consistent positive relationship between Ea and pH in both horizons. The Ea in the arctic and subarctic zones for peroxidase was lower than the hydrolases and phenol oxidase values, indicating peroxidase may be a rate limited enzyme in environments under warming conditions. By including these six soil types we have increased the number of soil oxidative enzyme Ea values reported in the literature by 50%. This study is a step towards better quantifying enzyme kinetics in different climate zones. PMID:23536898

Steinweg, J. Megan; Jagadamma, Sindhu; Frerichs, Joshua; Mayes, Melanie A.

2013-01-01

228

Simulation of Viking biology experiments suggests smectites not palagonites, as martian soil analogues  

NASA Technical Reports Server (NTRS)

An experimental comparison of palagonites and a smectite (montmorillonite) was performed in a simulation of the Viking Biology Labelled Release (LR) experiment in order to judge which mineral is a better Mars soil analog material (MarSAM). Samples of palagonite were obtained from cold weathering environments and volcanic soil, and the smectite was extracted from Wyoming Bentonite and converted to H or Fe types. Decomposition reaction kinetics were examined in the LR simulation, which on the Lander involved interaction of the martian soil with organic compounds. Reflectance spectroscopy indicated that smectites bearing Fe(III) in well-crystallized sites are not good MarSAMS. The palagonites did not cause the formate decomposition and C-14 emission detected in the LR, indicating that palagonites are also not good MarSAMS. Smectites, however, may be responsible for ion exchange, molecular adsorption, and catalysis in martian soil.

Banin, A.; Margulies, L.

1983-01-01

229

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

230

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

231

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

232

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

E-print Network

reflectance spectroscopy (NIRS) was used to predict six biological properties of soil and earthworm casts were to assess (i) the potential of NIRS to predict various biological attributes of soil and earthwormSoil Biology & Biochemistry 40: 1975-1979 (2008) ­ http://dx.doi.org/10.1016/j.soilbio.2008

Boyer, Edmond

233

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

234

Study of seleniferous soils using instrumental neutron activation analysis.  

PubMed

Soil samples from the seleniferous region of Punjab State in India were analyzed by instrumental neutron activation analysis (INAA) using reactor neutrons and high resolution ?-ray spectrometry. Samples were collected from three different depths namely surface, root and geological bed zones. Concentrations of 15 elements including selenium and arsenic were determined by relative method. For comparison purposes, soil samples collected from a non-seleniferous region were also analyzed. PMID:21334213

Srivastava, Alok; Bains, G S; Acharya, R; Reddy, A V R

2011-05-01

235

Urease activity and its Michaelis constant for soil systems  

Microsoft Academic Search

Summary Urea hydrolysis was measured in two separate sets of experiments. (1) Nine soil (0–15 cm) samples were treated with 200 ?g of urea-N g?1 dry soil and incubated (at 37°C) at 50 per cent of the water holding capacity. Samples were periodically analysed for the remaining urea-N. The urease activity (time in hoursrequired to hydrolyse half the applied urea-N)

Viraj Beri; K. P. Goswami; S. S. Brar

1978-01-01

236

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

E-print Network

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

Paris-Sud XI, Université de

237

Prologue: mind over molecule: activating biological demons.  

PubMed

The new vogue for systems biology is an important development. It is time to complement reductionist molecular biology by integrative approaches. But this welcome development is in danger of losing its way. Many of the early implementations of the approach are very low level, in some cases hardly more than an extension of genomics and bioinformatics. In this paper, I outline some general principles that could form the basis of systems biology as a truly multilevel approach. We need the insights obtained from a higher level analysis in order to succeed at the lower levels. Higher levels in biological systems impose boundary conditions on the lower levels. Without understanding those conditions and their effects, we will be seriously restricted in understanding the logic of living systems. Sydney Brenner has insisted that "the cell is the correct level of abstraction." I would go further and insist on the value of abstraction at even higher levels than the cell, while recognizing the cell as a landmark level of biological organization. The principles outlined are illustrated with examples from cardiac and other aspects of physiology and biochemistry. PMID:18375570

Noble, Denis

2008-03-01

238

Combined Passive Active Soil Moisture Observations During CLASIC  

Technology Transfer Automated Retrieval System (TEKTRAN)

An important issue in advancing higher spatial resolution and better accuracy in soil moisture remote sensing is the integration of active and passive observations. In an effort to address these questions an airborne passive/active L-band system (PALS) was flown as part of CLASIC in Oklahoma over th...

239

HEXAHYDRO-1,3,5-TRINITRO-1,3,5-TRIAZINE (RDX) DEGRADATION IN BIOLOGICALLY-ACTIVE IRON COLUMNS  

E-print Network

HEXAHYDRO-1,3,5-TRINITRO-1,3,5-TRIAZINE (RDX) DEGRADATION IN BIOLOGICALLY-ACTIVE IRON COLUMNS BYUNG iron barriers to treat groundwater contamination by RDX. Three columns were packed with iron filings (Fe0) between soil and sand layers, and were fed continuously with unlabeled plus 14C-labeled RDX

Alvarez, Pedro J.

240

Land Data Assimilation Activities in Preparation of the NASA Soil Moisture Active Passive (SMAP) Mission  

Technology Transfer Automated Retrieval System (TEKTRAN)

Slated for launch in 2013, the NASA Soil Moisture Active/Passive mission represents a generational advance in our ability to globally observe time and space variations in surface soil moisture fields. The SMAP mission concept is based on the integrated use of L-band active radar and passive radiome...

241

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

SciTech Connect

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

Neher, Deborah A. [University of Vermont

2004-08-31

242

Climate effect on soil enzyme activities and dissolved organic carbon in mountain calcareous soils: a soil-transplant experiment  

NASA Astrophysics Data System (ADS)

Mountain soils store huge amounts of carbon as soil organic matter (SOM) which may be highly vulnerable to the strong climate changes that mountain areas currently experience worldwide. Climate modifications are expected to impact microbial activity which could change the rate of SOM decomposition/accumulation, thereby questioning the net C source/sink character of mountain soils. To simulate future climate change expected in the 21st century in the calcareous pre-Alps, 15 blocks (30 cm deep) of undisturbed soil were taken from a mountain pasture located at 1400 m a.s.l. (Marchairuz, Jura, Switzerland) and transplanted into lysimeters at the same site (control) and at two other sites located at 1000 m a.s.l. and 600 m a.s.l. (5 replicates per site). This transplantation experiment which started in 2009 simulates a climate warming with a temperature increase of 4° C and a decreased humidity of 40 % at the lowest site. In this study, we used soil extracellular enzyme activities (EEA) as functional indicators of SOM decomposition to evaluate the effect of climate change on microbial activity and SOM dynamics along the seasons. Dissolved organic carbon (DOC) was also measured to quantify the assimilable carbon for microorganism. In autumn 2012, a first sampling step out of four (winter, spring and summer 2013) has been realized. We extracted 15 cm deep soil cores from each transplant (x15) and measured (i) DOC and (ii) the activities of nine different enzymes. Enzymes were chosen to represent the degradation of the most common classes of biogeochemical compounds in SOM. ?-glucosidase, ?-D-cellubiosidase, ?-Xylosidase, N-acetyl-?-glucosaminidase, leucine aminopeptidase, lipase, phenoloxidase respectively represented the degradation of sugar, cellulose, hemicellulose, chitin, protein, lipid and lignin. Moreover, the fluorescein diacetate (FDA) hydrolysis was used to provide an estimate of global microbial activity and phosphatase was used to estimate phosphorus mineralization. The autumn results showed no differences for global microbial activity along the climate gradient (0.37 nKatal g-1 dry soil), no differences and a very low activity for leucine aminopeptidase and ?-glucosidase and ?-Xylosidase (about 0.09 nKatal g-1 dry soil) and no differences for cellulose, chitin and phosphorus mineralization. Conversely, we measured a greater activity at the highest elevation site for lipase and phenoloxydase (ANOVA test, p

Puissant, Jérémy; Cécillon, Lauric; Mills, Robert T. E.; Gavazov, Konstantin; Robroek, Bjorn J. M.; Spiegelberger, Thomas; Buttler, Alexandre; Brun, Jean-Jacques

2013-04-01

243

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

PubMed Central

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

Mawa, Shukranul; Husain, Khairana; Jantan, Ibrahim

2013-01-01

244

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

245

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

246

Acid-activated biochar increased sulfamethazine retention in soils.  

PubMed

Sulfamethazine (SMZ) is an ionizable and highly mobile antibiotic which is frequently found in soil and water environments. We investigated the sorption of SMZ onto soils amended with biochars (BCs) at varying pH and contact time. Invasive plants were pyrolyzed at 700 °C and were further activated with 30 % sulfuric (SBBC) and oxalic (OBBC) acids. The sorption rate of SMZ onto SBBC and OBBC was pronouncedly pH dependent and was decreased significantly when the values of soil pH increased from 3 to 5. Modeled effective sorption coefficients (K D,eff) values indicated excellent sorption on SBBC-treated loamy sand and sandy loam soils for 229 and 183 L/kg, respectively. On the other hand, the low sorption values were determined for OBBC- and BBC700-treated loamy sand and sandy loam soils. Kinetic modeling demonstrated that the pseudo second order model was the best followed by intra-particle diffusion and the Elovich model, indicating that multiple processes govern SMZ sorption. These findings were also supported by sorption edge experiments based on BC characteristics. Chemisorption onto protonated and ligand containing functional groups of the BC surface, and diffusion in macro-, meso-, and micro-pores of the acid-activated BCs are the proposed mechanisms of SMZ retention in soils. Calculated and experimental q e (amount adsorbed per kg of the adsorbent at equilibrium) values were well fitted to the pseudo second order model, and the predicted maximum equilibrium concentration of SBBC for loamy sand soils was 182 mg/kg. Overall, SBBC represents a suitable soil amendment because of its high sorption rate of SMZ in soils. PMID:25172460

Vithanage, Meththika; Rajapaksha, Anushka Upamali; Zhang, Ming; Thiele-Bruhn, Sören; Lee, Sang Soo; Ok, Yong Sik

2015-02-01

247

Spatial variability of the dehydrogenase activity in forest soils  

NASA Astrophysics Data System (ADS)

The aim of this study was to assess the spatial variability of the dehydrogenase activity (DH) in forest soils using geostatistics. We have studied variability soil dehydrogenase and their relationship with variability of some physic-chemical properties. Two study areas (A and B) were set up in southern Poland in the Zlotoryja Forest District. Study areas were covered by different types of vegetation (A- broadleaf forest with beech, ash and sycamore), B- coniferous forest with Norway spruce). The soils were classified as Dystric Cambisols (WRB 2006). The samples for laboratory testing were collected from 49 places on each areas. 15 cm of surface horizon of soil were taken (with previously removed litter). Dehydrogenase activity was marked with Lenhard's method according to the Casida procedure. Soil pH, nitrogen (N) and soil organic carbon (C) content (by LECO CNS 2000 carbon analyzer) was marked. C/N ratio was calculated. Particle size composition was determined using laser diffraction. Statistical analysis were performed using STATISTICA 10 software. Geostatistical analysis and mapping were done by application of GS 9+ (Gamma Design) and Surfer 11 (Golden Software). The activity of DH ranged between 5,02 and 71,20 mg TPP• kg-1 •24 h-1 on the A area and between 0,94 and 16,47 mg TPP• kg-1 •24 h-1. Differences in spatial variability of the analised features were noted. The variability of dehydrogenase activity on the A study area was described by an exponential model, whereas on the B study area the spatial correlation has not been noted. The relationship of dehydrogenase activity with the remaining parameters of soil was noted only in the case of A study area. The variability of organic carbon content on the A and B study areas were described by an exponential model. The variability of nitrogen content on both areas were described by an spherical model.

B?o?ska, Ewa; Lasota, Jaros?aw

2014-05-01

248

DEPTH DISTRIBUTION OF SOIL ORGANIC MATTER AND ITS CONSEQUENCES ON SOIL PROPERTIES AND CROP PRODUCTIVITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil organic matter is a key component of soil quality that sustains many key soil functions by providing the energy, substrates, and biological diversity to support biological activity, which affects aggregation (important for habitat space, oxygen supply, and preventing soil erosion), infiltration...

249

Depth distribution of soil organic carbon as a signature of soil quality  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil organic matter is a key component of soil quality that sustains many key soil functions by providing the energy, substrates, and biological diversity to support biological activity, which affects aggregation (important for habitat space, oxygen supply, and preventing soil erosion), infiltration...

250

Fertilization regulates soil enzymatic activity and fertility dynamics in a cucumber field  

Microsoft Academic Search

Different fertilizers may affect soil enzymatic activity and soil fertility dynamics. These effects were investigated in a field experiment with cucumber (Cucumis sativus L.) and the relationship with yield and soil nutrient availability was assessed. Soil enzymatic activity, measured as phosphatase, catalase, invertase and urease activities, decreased in the early growth stages of cucumber, but increased in the late ones,

Lijuan Yang; Tianlai Li; Fusheng Li; J. Hugo Lemcoff; Shabtai Cohen

2008-01-01

251

Soil Biology & Biochemistry 38 (2006) 30573064 Fungal diversity in soils and historic wood from  

E-print Network

electrophoresis (DGGE) using the internal transcribed spacer (ITS) regions of ribosomal DNA for identification the historic woods sampled include Cadophora, Cladosporium and Geomyces. Similar genera were found in soil Cryptococcus spp., Epicoccum nigrum and Cladosporium cladosporioides as the most common fungi present

Blanchette, Robert A.

252

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

PubMed Central

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

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

2013-01-01

253

Activities of N-mineralization enzymes associated with soil aggregates in three different tillage systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil enzymes released by microorganisms play a significant role in N mineralization process that determines N availability for plant growth. Soil aggregates of different sizes provide diverse microhabitats for microorganisms and therefore influence soil enzyme activities. We hypothesize that enzyme ...

254

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

2014-05-27

255

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

2014-10-28

256

Synthesis, reactions and biological activities of furochromones: A review.  

PubMed

Furochromone derivatives are important synthetic targets which showed a myriad of interesting biological activities. Ammi visnaga (Umbelliferae) is the most famous source of these derivatives, which has been used in folk medicine for millennia targeting different ailments. Since the isolation of furochromone derivatives, different synthetic methodologies were developed for their preparation. Despite the recent interesting findings on this class of compounds, the chemical literatures lack a comprehensive summary on the synthetic methodologies and biological activities of furochromone derivatives. This review highlights recent advances in furochromones chemistry by discussing different synthetic procedures developed for the preparation of naturally occurring derivatives as well as other unique derivatives which showed promising biological activities. It also sheds light on the most common reactions of furochromone derivatives and the utilization of these derivatives as the blocks for many biologically active compounds. PMID:25499986

Abu-Hashem, Ameen A; El-Shazly, Mohamed

2015-01-27

257

[Effects of leaf litter replacement on soil biological and chemical characteristics in main artificial forests in Qinling Mountains].  

PubMed

Through 2 years leaf litter replacement experiments in 4 typical artificial pure forests Larix kaempferi, Pinus tabulaeformis, Catalpa fargesii, and Quercus aliena var. acuteserrata in Qinling Mountains of China, this paper studied the effects of leaf litter replacement on soil biological and chemical characteristics and the interspecific relationships between different tree species. The results showed that the annual decomposition rate of broad-leaved litter was 33.70% higher than that of needle-leaved litter. The annual decomposition rate of needle-leaved litter increased by 8.35%-12.15% when replaced to broad-leaved forests, whereas that of broad-leaved litter decreased by 5.38%-9.49% when replaced to needle-leaved forests. Leaf litter replacement between needle and broad-leaved forests could increase the contents of soil organic-C and available N, P and K, and the increments were obviously higher in needle-leaved forests (8.70%-35.84%) than in broad-leaved forests (3.73%-10.44%). In needle-leaved forests, the increments with the replacement of C. fargesii litter (24.63%-35.84%) were higher than those with the replacement of Q. aliena var. acuteserrata litter (8.70%-28.15%). Furthermore, the replacement of broad-leaved litter could make the soil pH in needle-leaved forests changed from light-acid to neutral, and increase soil enzyme activities, microbial amounts, and microbial biomass C and N contents. The increments with the replacement of C. fargesii litter were higher than those with the replacement of Q. aliena var. acuteserrata litter. The soil enzyme activities, microbial amounts, and microbial biomass C and N contents in broad-leaved forests after the replacement of needle-leaved litter differed with broadleaved tree species. Q. aliena var. acuteserrata forest had the higher soil enzyme activities and microbial biomass C and N contents, while C. fargesii forest was in adverse. It was suggested that in the control of soil degradation under artificial pure forests, much attention should be paid to the direction of interspecific relationship in mixed forestation and leaf litter replacement. PMID:18593025

Liu, Zeng-wen; Duan, Er-jun; Gao, Wen-jun; Zhang, Li-ping; Du, Hong-xia; Fu, Gang; Cui, Fang-fang

2008-04-01

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

Transport, stability, and biological activity of resveratrol.  

PubMed

Numerous studies have reported interesting properties of trans-resveratrol, a phytoalexin, as a preventive agent of several important pathologies: vascular diseases, cancers, viral infections, and neurodegenerative processes. These beneficial effects of resveratrol have been supported by observations at the cellular and molecular levels in both cellular and in vivo models, but the cellular fate of resveratrol remains unclear. We suggest here that resveratrol uptake, metabolism, and stability of the parent molecule could influence the biological effects of resveratrol. It appears that resveratrol stability involves redox reactions and biotransformation that influence its antioxidant properties. Resveratrol's pharmacokinetics and metabolism represent other important issues, notably, the putative effects of its metabolites on pathology models. For example, some metabolites, mainly sulfate-conjugated resveratrol, show biological effects in cellular models. The modifications of resveratrol stability, chemical structure, and metabolism could change its cellular and molecular targets and could be crucial for improving or decreasing its chemopreventive properties. PMID:21261641

Delmas, Dominique; Aires, Virginie; Limagne, Emeric; Dutartre, Patrick; Mazué, Frédéric; Ghiringhelli, François; Latruffe, Norbert

2011-01-01

260

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

261

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

262

Biological permeable reactive barriers coupled with electrokinetic soil flushing for the treatment of diesel-polluted clay soil.  

PubMed

Removal of diesel from spiked kaolin has been studied in the laboratory using coupled electrokinetic soil flushing (EKSF) and bioremediation through an innovative biological permeable reactive barriers (Bio-PRBs) positioned between electrode wells. The results show that this technology is efficient in the removal of pollutants and allows the soil to maintain the appropriate conditions for microorganism growth in terms of pH, temperature, and nutrients. At the same time, EKSF was demonstrated to be a very interesting technology for transporting pollutants, microorganisms and nutrients, although results indicate that careful management is necessary to avoid the depletion of nutrients, which are effectively transported by electro-migration. After two weeks of operation, 30% of pollutants are removed and energy consumption is under 70kWhm(-3). Main fluxes (electroosmosis and evaporation) and changes in the most relevant parameters (nutrients, diesel, microorganisms, surfactants, moisture conductivity and pH) during treatment and in a complete post-study analysis are studied to give a comprehensive description of the most relevant processes occurring in the soil (pollutant transport and biodegradation). PMID:25262485

Mena, Esperanza; Ruiz, Clara; Villaseñor, José; Rodrigo, Manuel A; Cañizares, Pablo

2015-02-11

263

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. PMID:24116193

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

2013-01-01

264

Successional stages of biological soil crusts and their microstructure variability in Shapotou region (China)  

Microsoft Academic Search

In order to investigate succession of biological soil crusts (BSCs) and their microstructure variability, we conducted this\\u000a work in Shapotou revegetation region at the southeast edge of Tengger Deser. The results showed that BSCs generally succeeded\\u000a as a pathway of “Algae crusts, algae–lichen crusts, lichen crusts, lichen–moss crusts and moss crusts”. Occasionally mosses\\u000a directly occurred on algae crusts, and BSCs

Shubin LanLi; Li Wu; Delu Zhang; Chunxiang Hu

265

Local knowledge and perception of biological soil crusts by land users in the Sahel (Niger)  

NASA Astrophysics Data System (ADS)

Local knowledge, i.e. knowledge based on accumulation of observations is of great interest for many scientific fields as it can help for identification, evaluation and selection of relevant indicators and furthermore for progress through conservation goals. This study aimed at gathering and understanding the local knowledge and perception of biological soil crusts (BSC) by users of land, pastoralists that cross the Sahel and sedentary farmers. The methodological approach is based on a semi-direct surveys conducted on a north-south rainfall gradient (350 to 650 mm/year) including agricultural- and pastoral-dominated areas in western Niger. Denomination, formation processes, occurrence, distribution and role of biological soil crusts are among the major issues of the inquiry. The results of the surveys showed that BSC are mainly identified by the names of "Bankwado" and "Korobanda", respectively in hausa and zarma langages, what means "toad back". Other denominations varying according to region, ethnic groups and users are used. They are all related to the aspects, colors and behaviour of BSC with regard wetting and drying cycle. From the point of view of users depressed areas and land lied fallow are favourable places for the occurrence of BSC, while cultivation and observed changes in rainfall regimes represent negative factors. The formation processes of BSC are mainly related to the occurrence and the impact of rain and wind on soil surface. Their roles in protecting soil against degradation or as an indicator of soil fertility were recognised by at least 83% of farmers and breeders. This study reveals significant aspects of BSC already validated by scientific knowledge. Integrating the two forms of knowledge will help to define relevant indicators of soil surface dynamics and to perform practices to minimize farming and grazing impacts on BSCs.

J-M Ambouta, K.; Hassan Souley, B.; Malam Issa, O.; Rajot, J. L.; Mohamadou, A.

2012-04-01

266

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

267

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

268

Effect of food waste compost on microbial population, soil enzyme activity and lettuce growth  

Microsoft Academic Search

The effect of food waste (FW) composted with MS® (Miraculous Soil Microorganisms) was compared with commercial compost (CC) and mineral fertilizer (MF) on bacterial and fungal populations, soil enzyme activities and growth of lettuce in a greenhouse. Populations of fungi and bacteria, soil biomass, and soil enzyme activities in the rhizosphere of FW treatments significantly increased compared to control (CON),

Jae-Jung Lee; Ro-Dong Park; Yong-Woong Kim; Jae-Han Shim; Dong-Hyun Chae; Yo-Sup Rim; Bo-Kyoon Sohn; Tae-Hwan Kim; Kil-Yong Kim

2004-01-01

269

The Soil Moisture Active and Passive (SMAP) Mission  

Technology Transfer Automated Retrieval System (TEKTRAN)

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 f...

270

ASSAY FOR FLUORESCEIN DIACETATE HYDROLYTIC ACTIVITY: OPTIMIZATION FOR SOIL SAMPLES  

Technology Transfer Automated Retrieval System (TEKTRAN)

With the increased interest in integrated soil bioecosystem studies, there has been a need to have a method of measuring overall microbial activity potential. Hydrolysis of fluorescein diacetate (3',6'-diacetylfluorescein [FDA]) has been suggested as a possible method because the ubiquitous lipase, ...

271

Soil moisture active/passive (SMAP) mission concept  

Technology Transfer Automated Retrieval System (TEKTRAN)

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. ...

272

Overview of the NASA soil moisture active/passive mission  

Technology Transfer Automated Retrieval System (TEKTRAN)

The NASA Soil Moisture Active Passive (SMAP) Mission is currently in design Phase C and scheduled for launch in October 2014. Its mission concept is based on combined L-band radar and radiometry measurements obtained from a shared, rotating 6-meter antennae. These measurements will be used to retrie...

273

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.

274

Feeding activity of the earthworm Eisenia andrei in artificial soil  

Microsoft Academic Search

Quantitative information on the feeding activity of earthworms is scarce but this information is valuable in many eco(toxico)logical studies. In this study, the feeding activity of the compost worm Eisenia andrei is examined in artificial soil (OECD medium), with and without a high-quality food source (cow manure), and at two temperatures (10 and 20°C). Methods are provided to estimate the

Tjalling Jager; Roel H. L. J. Fleuren; Willem Roelofs; Arthur C. de Groot

2003-01-01

275

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

276

Biological activity of Paecilomyces genus against Toxocara canis eggs  

Microsoft Academic Search

Saprophytic soil fungi can exert ovicidal and ovistatic effects on helminths with differing degrees of efficiency. The representatives\\u000a of such fungi from temperate regions, Paecilomyces lilacinus (Thom) Samson and P. marquandii (Masse) Hughes, exhibit recognized ovicidal activity on some nematodes. We evaluated the action in vitro of P. lilacinus and P. marquandii on the zoonotic canine roundworm eggs of Toxocara

J. A. Basualdo; M. L. Ciarmela; P. L. Sarmiento; M. C. Minvielle

2000-01-01

277

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

Microsoft Academic Search

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 precipita- tion patterns. In this study, we applied treatments to three

S USAN L. P HILLIPS; S T E P H A N F L I N Tw; J OHN M ONEY

278

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

279

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

280

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. PMID:23526933

Hartman, Wyatt H.; Richardson, Curtis J.

2013-01-01

281

Changes in plant communities along soil pollution gradients: responses of leaf antioxidant enzyme activities and phytochelatin contents.  

PubMed

This work describes an ecological and ecotoxicological study of polluted wasteland plant communities in a former coke-factory located in Homécourt (France). Ecological analyses were performed along two transects to investigate changes in plant community structure through species richness (S), biological diversity (H') and evenness (J). Five species (Arrhenatherum elatius, Bromus tectorum, Euphorbia cyparissias, Hypericum perforatum and Tanacetum vulgare) were then selected to assess cellular responses through antioxidant enzyme activities and phytochelatins (PCs) contents. The results showed that species richness and biological diversity correlated negatively to Cd and Hg concentrations in soil suggesting that soil concentration of non-essential heavy metals was the primary factor governing vegetation structure in the industrial wasteland. Moreover, for all studied species, abundances were partly related to metal levels in the soils, but also to plant antioxidant systems, suggesting their role in plant establishment success in polluted areas. Data for PC contents led to less conclusive results. PMID:19692108

Dazy, Marc; Béraud, Eric; Cotelle, Sylvie; Grévilliot, Frédérique; Férard, Jean-François; Masfaraud, Jean-François

2009-10-01

282

Biological activities of derivatized D-glucans: a review.  

PubMed

D-Glucans have triggered increasing interest in commercial applications in the chemical and pharmaceutical sectors because of their technological properties and biological activities. The glucans are foremost among the polysaccharide groups produced by microorganisms with demonstrated activity in stimulating the immune system, and have potential in treating human disease conditions. Chemical alterations in the structure of D-glucans through derivatization (sulfonylation, carboxymethylation, phosphorylation, acetylation) contributes to their increased solubility that, in turn, can alter their biological activities such as antioxidation and anticoagulation. This review surveys and cites the latest advances on the biological and technological potential of D-glucans following chemical modifications through sulfonylation, carboxymethylation, phosphorylation or acetylation, and discusses the findings of their activities. Several studies suggest that chemically modified d-glucans have potentiated biological activity as anticoagulants, antitumors, antioxidants, and antivirals. This review shows that in-depth future studies on chemically modified glucans with amplified biological effects will be relevant in the biotechnological field because of their potential to prevent and treat numerous human disease conditions and their clinical complications. PMID:25239192

Kagimura, Francini Yumi; da Cunha, Mário Antônio A; Barbosa, Aneli M; Dekker, Robert F H; Malfatti, Carlos Ricardo Maneck

2015-01-01

283

Photo-activated biological processes as quantum measurements  

E-print Network

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

Atac Imamoglu; K. Birgitta Whaley

2014-08-21

284

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

285

[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

286

Biologically active compounds of semi-metals.  

PubMed

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

Rezanka, Tomás; Sigler, Karel

2008-02-01

287

Measurements of Microbial Community Activities in Individual Soil Macroaggregates  

SciTech Connect

The functional potential of single soil aggregates may provide insights into the localized distribution of microbial activities better than traditional assays conducted on bulk quantities of soil. Thus, we scaled down enzyme assays for {beta}-glucosidase, N-acetyl-{beta}-D-glucosaminidase, lipase, and leucine aminopeptidase to measure of the enzyme potential of individual aggregates (250-1000 {mu}m diameter). Across all enzymes, the smallest aggregates had the greatest activity and the range of enzyme activities observed in all aggregates supports the hypothesis that functional potential in soil may be distributed in a patchy fashion. Paired analyses of ATP as a surrogate for active microbial biomass and {beta}-glucosidase on the same aggregates suggest the presence of both extracellular {beta}-glucosidase functioning in aggregates with no detectable ATP and also of relatively active microbial communities (high ATP) that have low {beta}-glucosidase potentials. Studying function at a scale more consistent with microbial habitat presents greater opportunity to link microbial community structure to microbial community function.

Bailey, Vanessa L.; Bilskis, Christina L.; Fansler, Sarah J.; McCue, Lee Ann; Smith, Jeff L.; Konopka, Allan

2012-05-01

288

Synthesis and biological activity of Citridone A and its derivatives.  

PubMed

Citridone A (1), originally isolated as a potentiator of antifungal miconazole activity from a fungal culture broth, has a phenyl-R-furopyridone structure. Because of its unique ring structure, 11 derivatives were chemically synthesized and their biological activity was evaluated. Derivatives 17, 20 and 21 potentiated miconazole activity against Candida albicans. Furthermore, 1, 14, 20 and 21 were found to inhibit yellow pigment production in methicillin-resistant Staphylococcus aureus. PMID:24643052

Fukuda, Takashi; Shimoyama, Kenta; Nagamitsu, Tohru; Tomoda, Hiroshi

2014-06-01

289

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

290

Physical aspects of biological activity and cancer  

NASA Astrophysics Data System (ADS)

Mitochondria are organelles at the boundary between chemical-genetic and physical processes in living cells. Mitochondria supply energy and provide conditions for physical mechanisms. Protons transferred across the inner mitochondrial membrane diffuse into cytosol and form a zone of a strong static electric field changing water into quasi-elastic medium that loses viscosity damping properties. Mitochondria and microtubules form a unique cooperating system in the cell. Microtubules are electrical polar structures that make possible non-linear transformation of random excitations into coherent oscillations and generation of coherent electrodynamic field. Mitochondria supply energy, may condition non-linear properties and low damping of oscillations. Electrodynamic activity might have essential significance for material transport, organization, intra- and inter-cellular interactions, and information transfer. Physical processes in cancer cell are disturbed due to suppression of oxidative metabolism in mitochodria (Warburg effect). Water ordering level in the cell is decreased, excitation of microtubule electric polar oscilations diminished, damping increased, and non-linear energy transformation shifted towards the linear region. Power and coherence of the generated electrodynamic field are reduced. Electromagnetic activity of healthy and cancer cells may display essential differences. Local invasion and metastastatic growth may strongly depend on disturbed electrodynamic activity. Nanotechnological measurements may disclose yet unknown properties and parameters of electrodynamic oscillations and other physical processes in healthy and cancer cells.

Pokorný, Ji?í

2012-03-01

291

Effects of altered temperature and precipitation on desert protozoa associated with biological soil crusts  

USGS Publications Warehouse

Biological soil crusts are diverse assemblages of bacteria, cyanobacteria, algae, fungi, lichens, and mosses that cover much of arid land soils. The objective of this study was to quantify protozoa associated with biological soil crusts and test the response of protozoa to increased temperature and precipitation as is predicted by some global climate models. Protozoa were more abundant when associated with cyanobacteria/lichen crusts than with cyanobacteria crusts alone. Amoebae, flagellates, and ciliates originating from the Colorado Plateau desert (cool desert, primarily winter precipitation) declined 50-, 10-, and 100-fold, respectively, when moved in field mesocosms to the Chihuahuan Desert (hot desert, primarily summer rain). However, this was not observed in protozoa collected from the Chihuahuan Desert and moved to the Sonoran desert (hot desert, also summer rain, but warmer than Chihuahuan Desert). Protozoa in culture began to encyst at 37??C. Cysts survived the upper end of daily temperatures (37-55??C), and could be stimulated to excyst if temperatures were reduced to 15??C or lower. Results from this study suggest that cool desert protozoa are influenced negatively by increased summer precipitation during excessive summer temperatures, and that desert protozoa may be adapted to a specific desert's temperature and precipitation regime. ?? 2006 by the International Society of Protistologists.

Darby, B.J.; Housman, D.C.; Zaki, A.M.; Shamout, Y.; Adl, S.M.; Belnap, J.; Neher, D.A.

2006-01-01

292

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

USGS Publications Warehouse

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

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

2013-01-01

293

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

294

Modelling chemical and biological reactions during unsaturated flow in silty arable soils  

NASA Astrophysics Data System (ADS)

Ion dynamics in arable soils are strongly affected by the chemical and biological transformations triggered by fertilizer input. Hydrogeochemical models may improve our understanding of underlying processes. Our objective was to test the ability of the hydrogeochemical model PHREEQC2 in combination with the parameter optimization programme PEST to describe and predict chemical and biological processes in silty soils triggered by fertilizer application or acidification and to investigate the usefulness of different parameterization approaches. Three different experiments were carried out using undisturbed columns of two topsoils (0-25 cm) from Germany (Göttingen, GO) and from the Oman (Qasha', QA). The columns were irrigated at 10 oC with 3 mm day-1 for one year using 1 mM HCl (HCl experiment) and two fertilizer solutions with low (0.1 to 0.9 mmol L-1) and high concentrations (1.3 to 14.7 mmol L-1) of N (as NH4NO3), K, Ca and Mg. In the fertilization experiments (Fert1, Fert2), the columns were alternately irrigated with the two different solutions for variable time periods. One-dimensional transport and homogenous and heterogenous reactions were calculated using PHREEQC2. The Fert1 experiment was used for calibration. The models were validated using the Fert2 and HCl experiments. The models tested were model variant m1 with no adjustable parameters, model variant m2 in which nitrate concentrations in input solutions and cation exchange capacity were optimized for Fert1, and m3 in which additionally all cation exchange coefficients and ion concentrations in the initial solution were optimized. Model variant m1 failed to predict the concentrations of several cations for both soils (modelling efficiencies (EF) ? 0), since N dynamics were not considered adequately. Model variants m2 and m3 described (Fert1 treatment) and predicted (Fert2 and HCl treatment) pH, cation and NO3- concentrations generally more accurately for both soils. For nutrient cations, EF values for prediction for GO ranged from 0.44 (K) to 0.99 (Ca), for QA from 0.21 (K) to 0.96 (Ca). After optimization, PHREEQC2 was able to predict NO3- concentrations in both soils (EF ? 0.57). Model variant m3 indicated that between 54 (QA) and 72 % (GO) of the exchange sites were involved in cation exchange reactions. Our results show the importance of the inclusion of nitrogen species when modelling cation dynamics in arable soils from different climate regions. The hydrogeochemical model PHREEQC2 in combination with PEST was useful to describe and predict ion dynamics in silty soils under unsaturated conditions.

Michel, Kerstin; Herrmann, Sandra; Ludwig, Bernard

2010-05-01

295

Influence of earthworm invasion on soil microbial biomass and activity in a northern hardwood forest  

Microsoft Academic Search

Recent invasion and activity of exotic earthworms has profoundly altered the chemical and physical environment of surface soils in northern hardwood forests that previously had mor humus horizons. We investigated the influence of earthworm invasion on soil microbial biomass and activity in surface soils of Allegheny northern hardwood forests in central New York state. Earthworm activity in these sites had

Xuyong Li; Melany C Fisk; Timothy J Fahey; Patrick J Bohlen

2002-01-01

296

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

297

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

298

Spatial distribution and physiology of biological soil crusts from semi-arid central Spain are related to soil chemistry and shrub cover  

Microsoft Academic Search

Despite the critical role of biological soil crusts (BSCs) in arid and semi-arid ecosystem function, few studies are found concerning the most important environmental variables affecting their distribution and physiology. This study seeks to determine soil and microenvironmental factors affecting the spatial distribution and pigment production of BSC-forming lichens and mosses in open patches of a semi-arid Mediterranean kermes oak

Raúl Ochoa-Hueso; Rebecca R. Hernandez; José J. Pueyo; Esteban Manrique

2011-01-01

299

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

300

Generation of biologically active substances in a natural gas flame  

SciTech Connect

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.

1987-06-01

301

Generation of biologically active substances in a natural gas flame.  

PubMed

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. PMID:3622438

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

1987-06-01

302

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

USGS Publications Warehouse

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

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

2004-01-01

303

Soil biology should be a conscious consideration in forest management. Yet, it is not. Historically, managers of western forests have focused on harvesting methods,  

E-print Network

Preface1 Soil biology should be a conscious consideration in forest management. Yet, it is not of forest ecosystem management, the soil often is overlooked or remains an afterthought for many "ecosystemologists." Even within the field of forest soils research, certain aspects of soil science have drawn more

Standiford, Richard B.

304

Modification of biological surface activity of particles  

PubMed Central

The hemolytic activity of fibrous asbestos varieties and of fibrous or granular silica dust can be markedly reduced by adsorption of polymers. Polyanions exert a specific action on asbestos, particularly chrysotile, whereas silica is inactivated by nonionic polymers. A high degree of reduction of the lytic action by comparatively small amounts of the antagonistic polymers can be demonstrated after short exposure to concentrations of 0.1–0.4 mg/ml of appropriate polymers. Inactivation is based on stable adsorption. Repeated washings of inactivated mineral sediments or exposure to elevated temperatures (80–120°C) produced no essential loss of the reduction of lytic potency. In one example, inactivation of chrysotile by sodium alginate, depolymerization by ascorbic acid was also ineffective. PMID:4377873

Schnitzer, R. J.

1974-01-01

305

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

306

Variations in soil aggregate stability and enzyme activities in a temperate agroforestry practice  

Microsoft Academic Search

Agroforestry and grass buffers have been shown to improve soil properties and overall environmental quality. The objective of this study was to examine management and landscape effects on water stable soil aggregates (WSA), soil carbon, soil nitrogen, enzyme activity, and microbial community DNA content. Treatments were row crop (RC), grass buffer (GB), agroforestry buffer (AG), and grass waterways (GWW). A

Ranjith P. Udawatta; Robert J. Kremer; Brandon W. Adamson; Stephen H. Anderson

2008-01-01

307

Azaglycomimetics: Natural Occurrence, Biological Activity, and Application  

NASA Astrophysics Data System (ADS)

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

Asano, Naoki

308

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

NASA Astrophysics Data System (ADS)

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

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

2009-08-01

309

Diurnally variable ?18O signatures of soil CO2 fluxes indicate carbonic anhydrase activity in a forest soil  

NASA Astrophysics Data System (ADS)

Oxygen isotopes are valuable tools for studying the gas exchange between terrestrial ecosystems and the atmosphere. We determined the ?18O signatures of soil CO2 fluxes from soil chamber measurements over the diurnal cycle in September 2000, May 2001 and July 2001 in a Sitka spruce plantation in Scotland. Concurrent estimates of the ?18O composition of soil water were obtained from soil samples collected in the vicinity of the chambers. The observed ?18O signatures of net soil CO2 fluxes were diurnally variable and strongly depleted compared to those expected from a simple evasion of respired CO2 at isotopic equilibrium with soil water. We then simulated the ?18O signatures of soil CO2 fluxes using a model of soil gas exchange that includes atmospheric invasion of CO2 with concurrent isotopic equilibration with soil water and evasion of the equilibrated CO2. This brought the modeled ?18O signatures closer to the observations, but complete agreement was only achieved when acceleration of isotopic exchange between CO2 and soil water by carbonic anhydrase activity was included. We hypothesize that carbonic anhydrase is present in the litter or surface soil layers. This introduces a feedback that can result in diurnally variable ?18O signatures of net soil CO2 fluxes. Such effects can only be captured in models that have an explicit description of the canopy air space with a variable ?18O signature of CO2.

Seibt, U.; Wingate, L.; Lloyd, J.; Berry, J. A.

2006-12-01

310

Mineral exploration and soil analysis using in situ neutron activation  

USGS Publications Warehouse

A feasibility study has been made to operate by remote control an unshielded portable positive-ion accelerator type neutron source to induce activities in the ground or rock by "in situ" neutron irradiation. Selective activation techniques make it possible to detect some thirty or more elements by irradiating the ground for periods of a few minutes with either 3-MeV or 14-MeV neutrons. The depth of penetration of neutrons, the effect of water content of the soil on neutron moderation, gamma ray attenuation in the soil and other problems are considered. The analysis shows that, when exploring for most elements of economic interest, the reaction 2H(d,n)3He yielding ??? 3-MeV neutrons is most practical to produce a relatively uniform flux of neutrons of less than 1 keV to a depth of 19???-20???. Irradiation with high energy neutrons (??? 14 MeV) can also be used and may be better suited for certain problems. However, due to higher background and lower sensitivity for the heavy minerals, it is not a recommended neutron source for general exploration use. Preliminary experiments have been made which indicate that neutron activation in situ is feasible for a mineral exploration or qualititative soil analysis. ?? 1976.

Senftle, F.E.; Hoyte, A.F.

1966-01-01

311

Soils contain more than one activity consuming carbonyl sulfide  

NASA Astrophysics Data System (ADS)

Exchange rates of carbonyl sulfide (OCS) were measured at 25°C in the laboratory in soil samples from a forest (PBE) and a former rape field (RA) over a range of OCS concentrations (250 - 120,000 pptv). The exchange of OCS changed from net production to net consumption above the OCS compensation concentration which was 785 pptv for PBE and 1470 pptv for RA. The OCS uptake rate constants were 0.17 and 0.14 l h -1 g -1 dry weight soil, respectively. However, at OCS concentrations higher than approximately 5000 pptv, uptake rate constants in RA became smaller suggesting saturation, and increased again at >50,000 pptv suggesting the existence of a second OCS consumption activity operating at elevated OCS concentrations. In PBE, the rate constant of OCS uptake increased at OCS concentrations higher than about 4000 pptv, also suggesting a second activity. Thus, our study indicated that OCS at close to ambient concentrations was consumed by a different activity than OCS at higher concentrations. Below the compensation point, the soil samples acted as a source rather than a sink for atmospheric OCS, stressing the necessity to measure OCS flux as function of OCS concentration to obtain reliable source or sink data for atmospheric budgets.

Conrad, Ralf; Meuser, Katja

312

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

313

The 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-tier projects recommended by the U.S. National Research Council Committee on Earth Science and Applications from Space. The SMAP mission is in formulation phase and it is scheduled for launch in 2014. The SMAP mission is designed to produce high-resolution and accurate global mapping of soil moisture and its freeze/thaw state using an instrument architecture that incorporates an L-band (1.26 GHz) radar and an L-band (1.41 GHz) radiometer. The simultaneous radar and radiometer measurements will be combined to derive global soil moisture mapping at 9 [km] resolution with a 2 to 3 days revisit and 0.04 [cm3 cm-3] (1 sigma) soil water content accuracy. The radar measurements also allow the binary detection of surface freeze/thaw state. The project science goals address in water, energy and carbon cycle science as well as provide improved capabilities in natural hazards applications.

Entekhabi, Dara; Njoku, Eni; ONeill, Peggy; Kellogg, Kent; Entin, Jared

2011-01-01

314

Comparison between geochemical and biological estimates of subsurface microbial activities  

Microsoft Academic Search

Geochemical and biological estimates of in situ microbial activities were compared from the aerobic and microaerophilic sediments of the Atlantic Coastal Plain. Radioisotope time-course experiments suggested oxidation rates greater than millimolar quantities per year for acetate and glucose. Geochemical analyses assessing oxygen consumption, soluble organic carbon utilization, sulfate reduction, and carbon dioxide production suggested organic oxidation rates of nano- to

T. J. Phelps; E. M. Murphy; S. M. Pfiffner; D. C. White

1994-01-01

315

Activity-Dependent Dendritic Release of BDNF and Biological Consequences  

E-print Network

Activity-Dependent Dendritic Release of BDNF and Biological Consequences Nicola Kuczewski, neurotrophins, and in particular brain-derived neurotrophic factor (BDNF), have emerged as attractive candidates-dependent refinement of local connections. In this paper, we provide an overview of recent findings showing that BDNF

Cossart, Rosa

316

Smart Sensing Strategies: Insights from a Biological Active Sensing System  

E-print Network

Smart Sensing Strategies: Insights from a Biological Active Sensing System Mark E. Nelson of smart sensing systems in diverse engineering applications. Certain freshwater fish from South America of visual cues. To achieve reliable, real-time performance, the nervous system implements a number of smart

Nelson, Mark E.

317

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

318

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

319

Invertebrate community characteristics in biologically active carbon filter  

Microsoft Academic Search

Biologically active carbon (BAC) system was set up in a water plant of South China during January to December 2007, to study the invertebrate community characteristics of BAC filter. Thirty-seven invertebrate species were found, of which 28 belonging to rotifers. Filter operation could lead to an output of invertebrates in high abundances with the filtrate, and the maximum density could

Xiaowei Li; Yufeng Yang; Lijun Liu; Jinsong Zhang; Qing Wang

2010-01-01

320

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

321

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 ...

322

The microbiology of biological phosphorus removal in activated sludge systems  

Microsoft Academic Search

Activated sludge systems are designed and operated globally to remove phosphorus microbiologically, a process called enhanced biological phosphorus removal (EBPR). Yet little is still known about the ecology of EBPR processes, the microbes involved, their functions there and the possible reasons why they often perform unreliably. The application of rRNA-based methods to analyze EBPR community structure has changed dramatically our

Robert J Seviour; Takashi Mino; Motoharu Onuki

2003-01-01

323

Preparation of Biologically Active Recombinant Human Progastrin 1–80  

Microsoft Academic Search

The bacterial expression of human progastrin6–80 has been reported previously [Baldwin, G.S. et al. (2001) J. Biol. Chem.276: 7791-7796]. The aims of the present study were to prepare full-length recombinant human progastrin1–80 and to compare its biological activity with that of progastrin6–80in vitro, to determine whether or not the N-terminal five amino acids contributed to activity. A fusion protein of

Kim McQueen; Suzana Kovac; Po-Ki Ho; Kristy Rorison; Julie Pannequin; Greg Neumann; Arthur Shulkes; Graham S. Baldwin

2002-01-01

324

Soil microbial activity, nitrogen cycling, and long-term changes in organic carbon pools as related to fallow tillage management  

Microsoft Academic Search

Two experiments were established in 1969 and 1970 near Sidney, NE, to determine the effect of moldboard plow (plow), sub-tillage (sub-till), and no-tillage (no-till) fallow management on soil properties, biological activities, and carbon and nitrogen cycling. One experiment was on land which had been broken from sod in 1920, seeded to crested wheatgrass [Agropyron cristatum (L.) Gaertn.] from 1957 to

J. W Doran; E. T Elliott; K Paustian

1998-01-01

325

Chemical and structural features influencing the biological activity of curcumin.  

PubMed

Curcumin, a polyphenolic natural product, exhibits therapeutic activity against a number of diseases, attributed mainly to its chemical structure and unique physical, chemical, and biological properties. It is a diferuloyl methane molecule [1,7-bis (4-hydroxy-3- methoxyphenyl)-1,6-heptadiene-3,5-dione)] containing two ferulic acid residues joined by a methylene bridge. It has three important functionalities: an aromatic o-methoxy phenolic group, ?, ?-unsaturated ?-diketo moiety and a seven carbon linker. Extensive research in the last two decades has provided evidence for the role of these different functional groups in its crucial biological activities. A few highlights of chemical structural features associated with the biological activity of curcumin are: The o-methoxyphenol group and methylenic hydrogen are responsible for the antioxidant activity of curcumin, and curcumin donates an electron/ hydrogen atom to reactive oxygen species. Curcumin interacts with a number of biomolecules through non-covalent and covalent binding. The hydrogen bonding and hydrophobicity of curcumin, arising from the aromatic and tautomeric structures along with the flexibility of the linker group are responsible for the non-covalent interactions. The ?, ?-unsaturated ?-diketone moiety covalently interacts with protein thiols, through Michael reaction. The ?-diketo group forms chelates with transition metals, there by reducing the metal induced toxicity and some of the metal complexes exhibit improved antioxidant activity as enzyme mimics. New analogues with improved activity are being developed with modifications on specific functional groups of curcumin. The physico-chemical and structural features associated with some of the biological activities of curcumin and important analogues are summarized in this article. PMID:23116315

Priyadarsini, K Indira

2013-01-01

326

Methyl-beta-cyclodextrin enhanced biodegradation of polycyclic aromatic hydrocarbons and associated microbial activity in contaminated soil.  

PubMed

The contamination of soils by polycyclic aromatic hydrocarbons (PAHs) is a widespread environmental problem and the remediation of PAHs from these areas has been a major concern. The effectiveness of many in situ bioremediation systems may be constrained by low contaminant bioavailability due to limited aqueous solubility or a large magnitude of sorption. The objective of this research was to evaluate the effect of methyl-beta-cyclodextrin (MCD) on bioaugmentation by Paracoccus sp. strain HPD-2 of an aged PAH-contaminated soil. When 10% (W/W) MCD amendment was combined with bioaugmentation by the PAH-degrading bacterium Paracoccus sp. strain HPD-2, the percentage degradation of total PAHs was significantly enhanced up to 34.8%. Higher counts of culturable PAH-degrading bacteria and higher soil dehydrogenase and soil polyphenol oxidase activities were observed in 10% (W/W) MCD-assisted bioaugmentation soil. This MCD-assisted bioaugmentation strategy showed significant increases (p < 0.05) in the average well color development (AWCD) obtained by the BIOLOG Eco plate assay, Shannon-Weaver index (H) and Simpson index (lambda) compared with the controls, implying that this strategy at least partially restored the microbiological functioning of the PAH-contaminated soil. The results suggest that MCD-aided bioaugmentation by Paracoccus sp. strain HPD-2 may be a promising practical bioremediation strategy for aged PAH-contaminated soils. PMID:22893972

Sun, Mingming; Luo, Yongming; Christie, Peter; Jia, Zhongjun; Li, Zhengao; Teng, Ying

2012-01-01

327

Soil structure and earthworm activity in a marine silt loam under pasture versus arable land  

Microsoft Academic Search

Agricultural management influences soil organic matter (SOM) and earthworm activity which interact with soil structure. We aimed to describe the change in earthworm activity and related soil (micro)structure and SOM in a loamy Eutrodept as affected by permanent pasture (PP) and conventional arable (CA). Thin sections were studied and biogenic calcite spheroids, worm casts, infillings and groundmass coatings were quantified.

A. G. Jongmans; M. M. Pulleman; J. C. Y. Marinissen

2001-01-01

328

Amidase activity in soils. IV. Effects of trace elements and pesticides  

Microsoft Academic Search

Amidase was recently detected in soils, and this study was carried out to assess the effects of 21 trace elements, 12 herbicides, 2 fungicides, and 2 insecticides on the activity of this enzyme. Results showed that most of the trace elements and pesticides studied inhibited amidase activity in soils. The degree of inhibition varied among the soils used. When the

Frankenberger W. T. Jr; M. A. Tabatabai

1981-01-01

329

Interaction Effects of Insecticides on Microbial Populations and Dehydrogenase Activity in a Black Clay Soil  

Microsoft Academic Search

Three insecticides, monocrotophos, quinalphos, and cypermethrin, were applied at 0, 5, 10, and 25 ? g g either singly or in combination to a black clay soil to investigate their effects on the soil microflora and dehydrogenase activity. All three insecticides significantly enhanced the proliferation of bacteria and fungi and the soil dehydrogenase activity even at the highest level of

Vijay A. K. B. Gundi; G. Narasimha; B. R. Reddy

2005-01-01

330

Soil Chemical Analysis Applied as an Interpretive Tool for Ancient Human Activities in Piedras Negras, Guatemala  

Microsoft Academic Search

The applicability of soil chemical analysis to the interpretation of ancient human activity areas in the Maya region was studied for potential implications in anthropogenically modified soils. We studied chemical signatures associated with a horizontally excavated site in Piedras Negras, Guatemala. The focus of this study is on soil phosphate and trace metals as indicators of ancient activity. We compared

J. Jacob Parnell; Richard E. Terry; Zachary Nelson

2002-01-01

331

Chemical structure of phenothiazines and their biological activity.  

PubMed

Phenothiazines belong to the oldest, synthetic antipsychotic drugs, which do not have their precursor in the world of natural compounds. Apart from their fundamental neuroleptic action connected with the dopaminergic receptors blockade, phenothiazine derivatives also exert diverse biological activities, which account for their cancer chemopreventive-effect, as: calmodulin- and protein kinase C inhibitory-actions, anti-proliferative effect, inhibition of P-glycoprotein transport function and reversion of multidrug resistance. According to literature data on relations between chemical structure of phenothiazines and their biological effects, the main directions for further chemical modifications have been established. They are provided and discussed in this review paper. PMID:22580516

Jaszczyszyn, Agata; G?siorowski, Kazimierz; ?wi?tek, Piotr; Malinka, Wies?aw; Cie?lik-Boczula, Katarzyna; Petrus, Joanna; Czarnik-Matusewicz, Bogus?awa

2012-01-01

332

The genus Pluchea: phytochemistry, traditional uses, and biological activities.  

PubMed

In this review, literature data on phytochemical and biological investigations on the genus Pluchea are compiled. Pluchea is a genus of flowering plants in the Asteraceae family and comprises ca. 80 species distributed mainly in Northern and Southern America, Africa, Asia, and Australia. Sesquiterpenoids and flavonoids are the main constituents of this genus. Compounds isolated from plants of the Pluchea genus display a variety of biological properties, viz., anticancer, antileishmanial, immunosuppressive, antioxidant, anti-acetylcholinesterase, antimicrobial, trypanocidal, hepatoprotective, cytotoxic, larvicidal, anti-ulcer, anti-inflammatory, and antinociceptive activities. PMID:24243605

Hussain, Hidayat; Al-Harrasi, Ahmed; Abbas, Ghulam; Rehman, Najeeb Ur; Mabood, Fazal; Ahmed, Ishtiaq; Saleem, Muhammad; van Ree, Teunis; Green, Ivan R; Anwar, Saeed; Badshah, Amin; Shah, Afzal; Ali, Iftikhar

2013-11-01

333

Chemical properties and toxicity of soils contaminated by mining activity.  

PubMed

This research is aimed at assessing the total content and soluble forms of metals (zinc, lead and cadmium) and toxicity of soils subjected to strong human pressure associated with mining of zinc and lead ores. The research area lay in the neighbourhood of the Boles?aw Mine and Metallurgical Plant in Bukowno (Poland). The study obtained total cadmium concentration between 0.29 and 51.91 mg, zinc between 7.90 and 3,614 mg, and that of lead between 28.4 and 6844 mg kg(-1) of soil d.m. The solubility of the heavy metals in 1 mol dm(-3) NH4NO3 was 1-49% for zinc, 5-45% for cadmium, and <1-10% for lead. In 1 mol HCl dm(-3), the solubility of the studied metals was much higher and obtained values depending on the collection site, from 45 to 92% for zinc, from 74 to 99%, and from 79 to 99% for lead. The lower solubility of the heavy metals in 1 mol dm(-3) NH4NO3 than 1 mol HCl dm(-3) is connected with that, the ammonium nitrate has low extraction power, and it is used in determining the bioavailable (active) form of heavy metals. Toxicity assessment of the soil samples was performed using two tests, Phytotoxkit and Microtox(®). Germination index values were between 22 and 75% for Sinapis alba, between 28 and 100% for Lepidium sativum, and between 10 and 28% for Sorghum saccharatum. Depending on the studied soil sample, Vibrio fischeri luminescence inhibition was 20-96%. The sensitivity of the test organisms formed the following series: S. saccharatum > S. alba = V. fischeri > L. sativum. Significant positive correlations (p ? 0.05) of the total and soluble contents of the metals with luminescence inhibition in V. fischeri and root growth inhibition in S. saccharatum were found. The general trend observed was an increase in metal toxicity measured by the biotest with increasing available metal contents in soils. All the soil samples were classified into toxicity class III, which means that they are toxic and present severe danger. Biotest are a good complement to chemical analyses in the assessment of quality of soils as well as in properly managing them. PMID:24903806

Agnieszka, Baran; Tomasz, Czech; Jerzy, Wieczorek

2014-09-01

334

Polyisoprenylated benzophenones in cuban propolis; biological activity of nemorosone.  

PubMed

The Copey tree (Clusia rosea) has a large distribution in Cuba and its floral resin is a rich source of polyisoprenylated benzophenones. To determine the presence of these natural products, we carried out a study by HPLC of 21 propolis samples produced by honey bees (Apis mellifera) from different provinces of Cuba. Nemorosone resulted to be the most abundant polyisoprenylated benzophenone and the mixture of xanthochymol and guttiferone E was also observed, but in minor proportion. We studied the biological activity of the pure natural product nemorosone and its methyl derivatives. We found that nemorosone has cytotoxic activity against epitheloid carcinoma (HeLa), epidermoid carcinoma (Hep-2), prostate cancer (PC-3) and central nervous system cancer (U251). It also exhibited antioxidant capacity. Methylated nemorosone exhibited less biological activity than the natural product. PMID:12064743

Cuesta-Rubio, Osmany; Frontana-Uribe, Bernardo A; Ramírez-Apan, Teresa; Cárdenas, Jorge

2002-01-01

335

Potential enzyme activities in cryoturbated organic matter of arctic soils  

NASA Astrophysics Data System (ADS)

An estimated 581 Gt organic carbon is stored in arctic soils that are affected by cryoturbtion, more than in today's atmosphere (450 Gt). The high amount of organic carbon is, amongst other factors, due to topsoil organic matter (OM) that has been subducted by freeze-thaw processes. This cryoturbated OM is usually hundreds to thousands of years old, while the chemical composition remains largely unaltered. It has therefore been suggested, that the retarded decomposition rates cannot be explained by unfavourable abiotic conditions in deeper soil layers alone. Since decomposition of soil organic material is dependent on extracellular enzymes, we measured potential and actual extracellular enzyme activities in organic topsoil, mineral subsoil and cryoturbated material from three different tundra sites, in Zackenberg (Greenland) and Cherskii (North-East Siberia). In addition we analysed the microbial community structure by PLFAs. Hydrolytic enzyme activities, calculated on a per gram dry mass basis, were higher in organic topsoil horizons than in cryoturbated horizons, which in turn were higher than in mineral horizons. When calculated on per gram carbon basis, the activity of the carbon acquiring enzyme exoglucanase was not significantly different between cryoturbated and topsoil organic horizons in any of the three sites. Oxidative enzymes, i.e. phenoloxidase and peroxidase, responsible for degradation of complex organic substances, showed higher activities in topsoil organic and cryoturbated horizons than in mineral horizons, when calculated per gram dry mass. Specific activities (per g C) however were highest in mineral horizons. We also measured actual cellulase activities (by inhibiting microbial uptake of products and without substrate addition): calculated per g C, the activities were up to ten times as high in organic topsoil compared to cryoturbated and mineral horizons, the latter not being significantly different. The total amount of PLFAs, as a proxy for microbial biomass, was significantly higher in topsoil organic horizons than in cryoturbated and mineral horizons. Changes in the microbial community composition were mainly caused by the relative amount of fungal biomarkers. Within the fungal community the biomarker 18:2w6, which is often associated with ectomycorrhiza, was negatively correlated to the general fungal biomarker 18:1w9. This negative correlation indicates a shift from mycorrhizal to saprotrophic fungi from topsoil towards cryoturbatad and mineral subsoil horizons. In summary, the measured oxidative and hydrolytic (potential) enzyme activities cannot explain the previously observed retarded decomposition in cryoturbated horizons. The measured actual cellulase activity however was strongly reduced in cryoturbated material compared to topsoil horizons. A possible explanation for the observed strong reduction of actual cellulase activity could lie within the fungal community structure which shifted towards saprotrophic fungi from topsoil to cryoturbated horizons.

Schnecker, J.; Wild, B.; Rusalimova, O.; Mikutta, R.; Guggenberger, G.; Richter, A.

2012-12-01

336

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

337

Diversity and dynamics of eco-units in the biological reserves of the Fontainebleau forest (France): Contribution of soil biology to a functional  

E-print Network

communities (Lumbricidae and Nematoda) pointed out two key aspects of forest functioning. First, the renewal / humus dynamics / biodiversity / soil biology / Lumbricidae / Nematoda / beech grove / ecosystem comportement des peuplements d'invertébrés du sol (Lumbricidae, Nematoda) mettent en avant deux points

Paris-Sud XI, Université de

338

Methanogens at the top of the world: occurrence and potential activity of methanogens in newly deglaciated soils in high-altitude cold deserts in the Western Himalayas.  

PubMed

Methanogens typically occur in reduced anoxic environments. However, in recent studies it has been shown that many aerated upland soils, including desert soils also host active methanogens. Here we show that soil samples from high-altitude cold deserts in the western Himalayas (Ladakh, India) produce CH4 after incubation as slurry under anoxic conditions at rates comparable to those of hot desert soils. Samples of matured soil from three different vegetation belts (arid, steppe, and subnival) were compared with younger soils originating from frontal and lateral moraines of receding glaciers. While methanogenic rates were higher in the samples from matured soils, CH4 was also produced in the samples from the recently deglaciated moraines. In both young and matured soils, those covered by a biological soil crust (biocrust) were more active than their bare counterparts. Isotopic analysis showed that in both cases CH4 was initially produced from H2/CO2 but later mostly from acetate. Analysis of the archaeal community in the in situ soil samples revealed a clear dominance of sequences related to Thaumarchaeota, while the methanogenic community comprised only a minor fraction of the archaeal community. Similar to other aerated soils, the methanogenic community was comprised almost solely of the genera Methanosarcina and Methanocella, and possibly also Methanobacterium in some cases. Nevertheless, ~10(3) gdw(-1) soil methanogens were already present in the young moraine soil together with cyanobacteria. Our results demonstrate that Methanosarcina and Methanocella not only tolerate atmospheric oxygen but are also able to survive in these harsh cold environments. Their occurrence in newly deglaciated soils shows that they are early colonizers of desert soils, similar to cyanobacteria, and may play a role in the development of desert biocrusts. PMID:24348469

Aschenbach, Katrin; Conrad, Ralf; Reháková, Klára; Doležal, Ji?í; Janatková, Kate?ina; Angel, Roey

2013-01-01

339

The Soil Moisture Active and Passive Mission (SMAP): Science and Applications  

E-print Network

The soil moisture active and passive mission (SMAP) will provide global maps of soil moisture content and surface freeze/thaw state. Global measurements of these variables are critical for terrestrial water and carbon cycle ...

Entekhabi, Dara

340

Fostering applications opportunities for the NASA Soil Moisture Active Passive (SMAP) mission  

E-print Network

The NASA Soil Moisture Active Passive (SMAP) Mission will provide global observations of soil moisture and freeze/thaw state from space. We outline how priority applications contributed to the SMAP mission measurement ...

Moran, M. Susan

341

78 FR 56153 - National Environmental Policy Act: Categorical Exclusions for Soil and Water Restoration Activities  

Federal Register 2010, 2011, 2012, 2013, 2014

...Act: Categorical Exclusions for Soil and Water Restoration Activities AGENCY: Forest...that restore lands negatively impacted by water control structures, disturbance events...potential environmental effects of soil and water restoration projects that are...

2013-09-12

342

Amendment application in a multi-contaminated mine soil: effects on soil enzymatic activities and ecotoxicological characteristics.  

PubMed

Several amendments were tested on soils obtained from an arsenopyrite mine, further planted with Arrhenatherum elatius and Festuca curvifolia, in order to assess their ability to improve soil's ecotoxicological characteristics. The properties used to assess the effects were: soil enzymatic activities (dehydrogenase, ?-glucosidase, acid phosphatase, urease, protease and cellulase), terrestrial bioassays (Eisenia fetida mortality and avoidance behaviour), and aquatic bioassays using a soil leachate (Daphnia magna immobilisation and Vibrio fischeri bioluminescence inhibition). The treatment with FeSO4 1 % w/w was able to reduce extractable As in soil, but increased the extractable Cu, Mn and Zn concentrations, as a consequence of the decrease in soil pH, in relation to the unamended soil, from 5.0 to 3.4, respectively. As a consequence, this treatment had a detrimental effect in some of the soil enzymatic activities (e.g. dehydrogenase, acid phosphatase, urease and cellulase), did not allow plant growth, induced E. fetida mortality in the highest concentration tested (100 % w/w), and its soil leachate was very toxic towards D. magna and V. fischeri. The combined application of FeSO4 1 % w/w with other treatments (e.g. CaCO3 1 % w/w and paper mill 1 % w/w) allowed a decrease in extractable As and metals, and a soil pH value closer to neutrality. As a consequence, dehydrogenase activity, plant growth and some of the bioassays identified those as better soil treatments to this type of multi-contaminated soil. PMID:24337998

Manzano, Rebeca; Esteban, Elvira; Peñalosa, Jesús M; Alvarenga, Paula

2014-03-01

343

Isothiocyanate synthetic analogs: biological activities, structure-activity relationships and synthetic strategies.  

PubMed

Sulforaphane is a natural product that is constantly under biological investigation for its unique biological properties. This naturally occurring isothiocyanate (ITC) and its analogs are the main components of cruciferous vegetables, such as cauliflower, watercress, broccoli, cabbage, Brussels sprouts, widely used as chemopreventive agents. Due to their interesting biological profiles, natural ITCs have been exploited as starting point to develop new synthetic analogs. The present mini-review briefly highlights the most important biological actions of selected new synthetic ITCs focusing on their structure-activity relationships and related synthetic strategies. PMID:25373847

Milelli, Andrea; Fimognari, Carmela; Ticchi, Nicole; Neviani, Paolo; Minarini, Anna; Tumiatti, Vincenzo

2014-11-11

344

The effect of fertilisation on soil nitrifier activity in experimental grassland plots  

Microsoft Academic Search

Soil nitrification was compared in soils from 89-year-old grassland experimental plots with diverse chemical characteristics. Measurements of NaClO3-inhibited short-term nitrifier activity (SNA) and deamination of 1,2-diamino-4-nitrobenzene were used to study nitrification and deamination activities, respectively, in soil from each of 12 plots. Using multiple regression analysis, an expression for the relationship between SNA, soil pH and fertiliser N additions was

D. W. Hopkins; A. G. O'Donnell; R. S. Shiel

1988-01-01

345

Antioxidant, Pro-oxidant and Other Biological Activities of Sesquiterpenes.  

PubMed

Sesquiterpenes, 15-carbon compounds formed from 3 isoprenoid units, are secondary metabolites produced mainly in higher plants but also in fungi and invertebrates. Sesquiterpenes occur in human food, but they are principally taken as components of many folk medicines and dietary supplements. Moreover, sesquiterpenes could become a rich reservoir of candidate compounds for drug discovery as several sesquiterpenes and their derivatives possess interesting biological activities.Recent efforts in the research and development of new drugs derived from natural products have led to the identification of a variety of sesquiterpenes that possess promising anti-inflammatory, anti-parasitic and anti-carcinogenic activities. On the other hand, some sesquiterpenes can cause serious toxicity and other adverse effects. Therefore, more and more attention has been paid to the investigation of the mechanisms of biological activities of sesquiterpenes in vitro as well as in vivo. The data collected in this review shows that many of sesquiterpenes biological activities are based on antioxidant or pro-oxidant actions of sesquiterpenes. Structure, concentration, metabolism as well as type of cells determine if sesquiterpene acts as anti-oxidant or pro-oxidant. Therefore, detailed research of sesquiterpenes is very important for evaluation of their efficacy and for their safe use. PMID:25478887

Bártíková, Hana; Hanušová, Veronika; Skálová, Lenka; Ambrož, Martin; Boušová, Iva

2014-12-01

346

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

347

Influence of age and composition of shelterbelts plants on enzyme activity and auxine - phytophormone IAA concentrations in soils  

NASA Astrophysics Data System (ADS)

The investigations were carried out in Dezydery Chlapowski Agroecological Landscape Park in Turew (40 km South-West of Pozna?, West Polish Lowlands, 16° 45 E and 52° 01 N). The soil samples were taken from two shelterbelts differing the age and the composition of trees. First 200-years-old shelterbelt is consisting mainly by Robinia pseudacacia and small admixture of Quercus robur and Larix deciduas. It has 2 kilometers of length and 36 meters of width. The second one new shelterbelt (many species) was created in 1993 and consists of several species of plants such as: Quercus pertraea and Quercus robur, Larix decidua, Pinus silvestris, Sorbus aucuparia, Sorbus intermedia and Tilia cordata. Its length is 340 meters and its width is 17.5 meters. All shelterbelts and adjoining cultivated fields were introduced on Hapludalfs soils (according to FAO classification). In soil under two shelterbelts and adjoining cultivated fields the activity of the following enzymes nitrate reductase, urease, xanthine oxidase, phenol oxidase, peroxidase activity were measured. In addition, the concentrations of iron ions, indole-3-acetic acids, total organic carbon, dissolved organic carbon, total nitrogen, ammonium and nitrates were determined. In soils under shelterbelts compared to adjoining cultivated fields higher content of organic matter was observed, because the accumulation of soil organic matter under shelterbelts is suggested to be the main mechanism of long-term withdrawal of various chemical elements from cycling in the agroecosystems. However, many chemical, biochemical, physical and biological processes control conversions of organic compounds in soils and finally these processes depend on the organic matter content and particularly on humic substances. Due to a very good developed root system of trees in shelterbelts than cultivated plants, they transpire more than 34% water than cultivated fields and intensively take up nutrients and finally improve quality of ground and surface water. The acidity of the soil under the 200-years-old shelterbelt was the highest and during the entire vegetation season pH ranged from 3.19 to 3.51, while for the soil of adjoining cultivated field pH values were much higher (5.03-5.65). However, there are not much differences between pH of the soil under young shelterbelt (created in 1993) and the soil of adjoining cultivated field (3.73-5.25 and 3.72-4.15, respectively). The activities of enzymes and all chemical compounds were the highest in soil under 200-years-old shelterbelt than in soil under young shelterbelt and two adjoining cultivated fields to both shelterbelts.

Wojciech Szajdak, Lech; Gaca, Wioletta; Meysner, Teresa; Sty?a, Katarzyna; Maryganova, Victoria

2010-05-01

348

Biological activities and medicinal properties of Cajanus cajan (L) Millsp.  

PubMed Central

Cajanus cajan (L) Millsp. (Sanskrit: Adhaki, Hindi: Arhar, English: Pigeon pea, Bengali: Tur) (family: Fabaceae) is the most important grain legume crop of rain-fed agriculture in semi-arid tropics. It is both a food crop and a cover/forage crop with high levels of proteins and important amino acids like methionine, lysine and tryptophan. During the last few decades extensive studies have been carried out regarding the chemistry of C. cajan and considerable progress has been achieved regarding its biological activities and medicinal applications. This review article gives an overview on the biological activities of the compounds isolated, pharmacological actions and clinical studies of C. cajan extracts apart from its general details. PMID:22247887

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

2011-01-01

349

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. PMID:23569975

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

2012-01-01

350

Biological Significance of Local TGF-? Activation in Liver Diseases  

PubMed Central

The cytokine transforming growth factor-? (TGF-?) plays a pivotal role in a diverse range of cellular responses, including cell proliferation, apoptosis, differentiation, migration, adhesion, angiogenesis, stimulation of extracellular matrix (ECM) synthesis, and downregulation of ECM degradation. TGF-? and its receptors are ubiquitously expressed by most cell types and tissues in vivo. In intact adult tissues and organs, TGF-? is secreted in a biologically inactive (latent) form associated in a non-covalent complex with the ECM. In response to injury, local latent TGF-? complexes are converted into active TGF-? according to a tissue- and injury type-specific activation mechanism. Such a well and tightly orchestrated regulation in TGF-? activity enables an immediate, highly localized response to type-specific tissue injury. In the pathological process of liver fibrosis, TGF-? plays as a master profibrogenic cytokine in promoting activation and myofibroblastic differentiation of hepatic stellate cells, a central event in liver fibrogenesis. Continuous and/or persistent TGF-? signaling induces sustained production of ECM components and of tissue inhibitor of metalloproteinase synthesis. Therefore, the regulation of locally activated TGF-? levels is increasingly recognized as a therapeutic target for liver fibrogenesis. This review summarizes our present knowledge of the activation mechanisms and bioavailability of latent TGF-? in biological and pathological processes in the liver. PMID:22363291

Hayashi, Hiromitsu; Sakai, Takao

2012-01-01

351

Quantitative NMR spectroscopy of biologically active substances and excipients  

Microsoft Academic Search

Biologically active ingredients and excipients are the essentials of a drug formulation, such as a tablet, dragee, solution,\\u000a etc. Quality control of such substances thus plays a pivotal role in the production process of pharmaceutical drugs. Since\\u000a these agents often exhibit complex structures, consist of multiple components, or lack of a chromophore, traditional means\\u000a of characterization are often not feasible.

Tanja Beyer; Bernd Diehl; Ulrike Holzgrabe

2010-01-01

352

Dimerization, ROS formation, and biological activity of o-methoxyphenols  

Microsoft Academic Search

Summary o-Methoxyphenols are antioxidants widely used in the cosmetic and food industries. Dimers from 1, 2, or 3 were synthesized and their radical-scavenging and biological activ- ities were compared with those of the original or other phenols. Radical-scavenging was evaluated from a kinetic induction period method (IPM). To simulate biomimetic thiol- cooxidation with antioxidants, the behavior of mixtures of 1,

Seiichiro Fujisawa; Toshiko Atsumi; Yukio Murakami; Yoshinori Kadoma

353

Soil Biology & Biochemistry 40 (2008) 986994 Potential fluxes of N2O and CH4 from soils of three forest  

E-print Network

types in Eastern Canada. Soil samples collected from deciduous, black spruce and white pine forests were-response to mineral N additions. Soils in deciduous, boreal and white pine forests consumed CH4 when incubated under an elevated headspace CH4 concentration, except the poorly drained soils in the deciduous forest, which

Moore, Tim

354

Microbial life in frozen boreal soils-environmental constraints on catabolic and anabolic activity  

NASA Astrophysics Data System (ADS)

Microbial activity in frozen soils has recently gained increasing attention and the fact that soil microorganisms can perform significant metabolic activity at temperatures below freezing is apparent. However, to what extent microbial activity is constrained by the environmental conditions prevailing in a frozen soil matrix is still very uncertain. This presentation will address how the fundamental environmental factors of temperature, liquid water availability and substrate availability combine to regulate rates of catabolic and anabolic microbial processes in frozen soils. The presented results are gained from investigations of the surface layers of boreal forest soils with seasonal freezing. We show that the amount and availability of liquid water is an integral factor regulating rates of microbial activity in the frozen soil matrix and can also explain frequently observed deviations in the temperature responses of biogenic CO2 production in frozen soils, as compared to unfrozen soils. In turn, the capacity for a specific soil to retain liquid water at sub-zero temperatures is controlled by the structural composition of the soil, and especially the soil organic matter is of integral importance. We also show that the partitioning of substrate carbon, in the form of monomeric sugar (glucose), for catabolic and anabolic metabolism remain constant in the temperature range of -4C to 9C. This confirms that microbial growth may proceed even when soils are frozen. In addition we present corresponding data for organisms metabolizing polymeric substrates (cellulose) requiring exoenzymatic activity. We conclude that the metabolic response of soil microorganism to controlling factors may change substantially across the freezing point of soil water, and also the patterns of interaction among controlling factors are affected. Thus, it is evident that metabolic response functions derived from investigations of unfrozen soils cannot be superimposed on frozen soils. Nonetheless, the soil microbial population appear very adapted to seasonal freezing with respect to their metabolic performance.

Oquist, M. G.; Sparrman, T.; Haei, M.; Segura, J.; Schleucher, J.; Nilsson, M. B.

2013-12-01

355

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

356

Effect of organic amendments on microbial activity in chlorpyrifos contaminated soil.  

PubMed

The aim of this research was to study the inhibitory effect of chlorpyrifos (CPF) on soil microbial activity and to evaluate the efficacy of different organic amendments as a biostimulation agent for sustaining the microbial activity and thereby assisting in the remediation of CPF (10 ppm) contaminated soil. Experiments were carried out under controlled conditions (37 °C) up to 74 days; CPF was analyzed by GC-ECD while dehydrogenase activity (DHA) was measured as one of the indices of soil microbial activity. Throughout the experiment, there was higher microbial activity in uncontaminated soil (S) as compared to CPF contaminated soil (SP) and overall a considerably high reduction (63.51%) in average DHA was noticed in CPF contaminated soil. Organic amendments enhanced the microbial activity over unamended CPF contaminated soil. The trend of DHA on 24th day was MS (SP + 1% Mushroom Spent) >VC (SP + 1% Vermicompost) >BS (SP + 1% Biogas Slurry) >SP (Soil spiked with 10 ppm CPF) >FM (SP + 1% Farmyard Manure). The enhancement in pesticide dissipation over the unamended soil showed the following trend VC (37%)>MS (24%) >FM (1.9%). In spite of sufficient DHA, BS could not enhance pesticide dissipation over the unamended soil (SP). These results indicate the potential of vermicompost and mushroom spent compost as suitable biostimulation agents to sustain the microbial activity in CPF contaminated soil. PMID:21035243

Kadian, Neeru; Malik, Anushree; Satya, Santosh; Dureja, Prem

2012-03-01

357

Integrity and Biological Activity of DNA after UV Exposure  

NASA Astrophysics Data System (ADS)

The field of astrobiology lacks a universal marker with which to indicate the presence of life. This study supports the proposal to use nucleic acids, specifically DNA, as a signature of life (biosignature). In addition to its specificity to living organisms, DNA is a functional molecule that can confer new activities and characteristics to other organisms, following the molecular biology dogma, that is, DNA is transcribed to RNA, which is translated into proteins. Previous criticisms of the use of DNA as a biosignature have asserted that DNA molecules would be destroyed by UV radiation in space. To address this concern, DNA in plasmid form was deposited onto different surfaces and exposed to UVC radiation. The surviving DNA was quantified via the quantitative polymerase chain reaction (qPCR). Results demonstrate increased survivability of DNA attached to surfaces versus non-adsorbed DNA. The DNA was also tested for biological activity via transformation into the bacterium Acinetobacter sp. and assaying for antibiotic resistance conferred by genes encoded by the plasmid. The success of these methods to detect DNA and its gene products after UV exposure (254 nm, 3.5 J/m2s) not only supports the use of the DNA molecule as a biosignature on mineral surfaces but also demonstrates that the DNA retained biological activity.

Lyon, Delina Y.; Monier, Jean-Michel; Dupraz, Sébastien; Freissinet, Caroline; Simonet, Pascal; Vogel, Timothy M.

2010-04-01

358

Movement and biological activity of drip-applied 1,3-dichloropropene and chloropicrin in raised mulched beds in the southeastern USA  

Microsoft Academic Search

Movement and biological activity of 1,3-dichloropropene (1,3-D) and chloropicrin applied through drip irrigation in raised beds was investigated at three locations in the southeastern USA. Tests were conducted in fields with dense populations of nutsedge (Cyperus spp), with one location also having a high level of soil nematodes, both of which served as biological indicators of the distribution of effective

Johan AJ Desaeger; Joe E Eger Jr; Alex S Csinos; James P Gilreath; Steve M Olson; Theodore M Webster

2004-01-01

359

Multi-bioindicators to assess soil microbial activity in the context of an artificial groundwater recharge with treated wastewater: a large-scale pilot experiment.  

PubMed

In the context of artificial groundwater recharge, a reactive soil column at pilot-scale (4.5 m depth and 3 m in diameter) fed by treated wastewater was designed to evaluate soil filtration ability. Here, as a part of this project, the impact of treated wastewater filtration on soil bacterial communities and the soil's biological ability for wastewater treatment as well as the relevance of the use of multi-bioindicators were studied as a function of depth and time. Biomass; bacterial 16S rRNA gene diversity fingerprints; potential nitrifying, denitrifying, and sulfate-reducing activities; and functional gene (amo, nir, nar, and dsr) detection were analyzed to highlight the real and potential microbial activity and diversity within the soil column. These bioindicators show that topsoil (0 to 20 cm depth) was the more active and the more impacted by treated wastewater filtration. Nitrification was the main activity in the pilot. No sulfate-reducing activity or dsr genes were detected during the first 6 months of wastewater application. Denitrification was also absent, but genes of denitrifying bacteria were detected, suggesting that the denitrifying process may occur rapidly if adequate chemical conditions are favored within the soil column. Results also underline that a dry period (20 days without any wastewater supply) significantly impacted soil bacterial diversity, leading to a decrease of enzyme activities and biomass. Finally, our work shows that treated wastewater filtration leads to a modification of the bacterial genetic and functional structures in topsoil. PMID:24608565

Michel, Caroline; Joulian, Catherine; Ollivier, Patrick; Nyteij, Audrey; Cote, Rémi; Surdyk, Nicolas; Hellal, Jennifer; Casanova, Joel; Besnard, Katia; Rampnoux, Nicolas; Garrido, Francis

2014-06-28

360

Concise synthesis of 2-benzazepine derivatives and their biological activity.  

PubMed

2-Benzazepines, which are potentially good candidates for new drug therapies to treat skin wounds, were readily prepared from substituted cinnamylamide via an intramolecular Friedel-Crafts reaction. With few steps and effective reactions, the procedure enables a rapid derivatization of 2-benzazepines. Moreover, optically active 4-substituted-2-benzazepines were prepared from chiral ?-substituted cinnamylamides, which were readily prepared by asymmetric ?-alkylation of chiral cinnamyl oxazolidinone amides. We have easily prepared a library of more than 20 derivatives and examined the biological activity of the compounds. PMID:22463127

So, Masahiro; Kotake, Tomoko; Matsuura, Kenji; Inui, Makoto; Kamimura, Akio

2012-04-20

361

Soil lichen and moss cover and species richness can be highly dynamic: The effects of invasion by the annual exotic grass Bromus tectorum, precipitation, and temperature on biological soil crusts in SE Utah  

Microsoft Academic Search

Biological soil crusts are an essential part of desert ecosystems throughout the world, as they are important in soil stabilization and soil fertility. Despite their importance, there have been few efforts to examine the population dynamics of the dominant species comprising these crusts or the effect of exotic plant invasions on these dynamics. In this study, we followed changes in

Jayne Belnap; Susan L. Phillips; Tonya Troxler

2006-01-01

362

Why Control Activity? Evolutionary Selection Pressures Affecting the Development of Physical Activity Genetic and Biological Regulation  

PubMed Central

The literature strongly suggests that daily physical activity is genetically and biologically regulated. Potential identities of the responsible mechanisms are unclear, but little has been written concerning the possible evolutionary selection pressures leading to the development of genetic/biological controls of physical activity. Given the weak relationship between exercise endurance and activity levels and the differential genomic locations associated with the regulation of endurance and activity, it is probable that regulation of endurance and activity evolved separately. This hypothesis paper considers energy expenditures and duration of activity in hunter/gatherers, pretechnology farmers, and modern Western societies and considers the potential of each to selectively influence the development of activity regulation. Food availability is also considered given the known linkage of caloric restriction on physical activity as well as early data relating food oversupply to physical inactivity. Elucidating the selection pressures responsible for the genetic/biological control of activity will allow further consideration of these pressures on activity in today's society, especially the linkages between food and activity. Further, current food abundance is removing the cues for activity that were present for the first 40,000 years of human evolution, and thus future research should investigate the effects of this abundance upon the mechanisms regulating activity. PMID:24455728

2013-01-01

363

A novel ?-glucosidase with lipolytic activity from a soil metagenome.  

PubMed

Moonlighting proteins have two different functions within a single polypeptide chain. Exploring moonlighting enzymes from the environment using the metagenomic approach is interesting. In the present study, a novel ?-glucosidase gene, designated as bgl1D, with lipolytic activity (renamed Lip1C) was cloned through function-based screening of a metagenomic library from uncultured soil microorganisms. The deduced amino acid sequence comparison and phylogenetic analysis also indicated that Lip1C and other putative lipases are closely related. Biochemical characterization demonstrated that the maximum activity of the recombinant Lip1C protein occurs at pH 8.0 and 30°C using 4-nitrophenyl butyrate as substrate. The putative lipase had an apparent K(m) value of 0.88 mmol/L, a k(cat) value of 212/min, and a k(cat)/K(m) value of 241 L/mmol/min. Lip1C exhibited habitat-specific characteristics with 5 mmol/L AlCl(3), CuCl(2), and LiCl. The characterization of the biochemical properties of Lip1C enhances our understanding of this novel moonlighting enzyme isolated from a soil metagenome. PMID:22116645

Jiang, Cheng-Jian; Chen, Gao; Huang, Jie; Huang, Qin; Jin, Ke; Shen, Pei-Hong; Li, Jun-Fang; Wu, Bo

2011-11-01

364

The role of macrosymbiont genotypes and earthworms in the enrichment of soil with biological nitrogen  

NASA Astrophysics Data System (ADS)

The specific features of the symbiotic apparatus and the accumulation of the plant biomass under the influence of different genotypes of peas ( Pisum sativum L.) on gray forest soils were studied in field conditions. With the alternation of legume and grass cultures, the genotypes of plants with supernodulation were found to affect the microbial nitrogen content in the soil to a greater extent than the concentration of ammonium and nitrate nitrogen. For the growing period, the N content in the microbial biomass increased, on the average, by 1.3 to 1.5 times. The consumption of nitrogen by the plants of the supernodular mutant K-301a was found to be 2.6 and 3.0 times greater than that by the pea plants of the Ramonskii-77 variety and of the K-562a line, respectively. During the after effect of the symbiotically bound air nitrogen, a significant uptake of this element was observed only by the oat plants grown after the K-56 2a. The nitrogen fixation by these plants was 1.3 times more active than that by the peas of the Ramonskii-77 variety. The importance of earthworms (Lumbricidae) and plant residues of different genotypes for the processes of mineralization of organic compounds and accumulation of ammonium, nitrate, and microbial nitrogen in the soils under optimal hydrothermal conditions was revealed. In the experiment, two maximums of the CO2 emission were recorded; they may be related to the periodic production of organic mass by the earthworms and the creation of favorable conditions for microbial activity by them. The accumulation of nitrate nitrogen (up to 150 mg/kg) in the soil was the greatest owing to the interaction between the earthworms and the residues of the supernodular K-301a mutant.

Nazaryuk, V. M.; Kalimullina, F. R.; Klenova, M. I.

2010-06-01

365

Calibration and validation of the soil moisture active passive mission with USDA-ARS experimental watersheds  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Soil Moisture Active Passive Mission (SMAP) is a new NASA mission scheduled for 2014 that will provide a number of soil moisture and freeze/thaw products. The soil moisture products will span spatial resolutions from 3 to 36 km. Key to the validation and calibration of the satellite products are...

366

Microbial biomass and activities in soil as affected by frozen and cold storage  

Microsoft Academic Search

When monitoring microbial biomass and activities in soil, the storage conditions of the soil samples prior to analysis may be decisive for the results. Studies made on freshly collected soils are generally preferred but these are not always possible for practical reasons, since sampling is often restricted to short periods of the year, e.g. due to climatic conditions. The most

B. Stenberg; M. Johansson; M. Pell; K. Sjödahl-Svensson; J. Stenström; L. Torstensson

1998-01-01

367

Methanogenic archaea are globally ubiquitous in aerated soils and become active under wet anoxic conditions  

Microsoft Academic Search

The prototypical representatives of the Euryarchaeota—the methanogens—are oxygen sensitive and are thought to occur only in highly reduced, anoxic environments. However, we found methanogens of the genera Methanosarcina and Methanocella to be present in many types of upland soils (including dryland soils) sampled globally. These methanogens could be readily activated by incubating the soils as slurry under anoxic conditions, as

Roey Angel; Peter Claus; Ralf Conrad

2012-01-01

368

Molecular biological access to the chemistry of unknown soil microbes: a new frontier for natural products  

Microsoft Academic Search

Cultured soil microorganisms have provided a rich source of natural-product chemistry. Because only a tiny fraction of soil microbes from soil are readily cultured, soil might be the greatest untapped resource for novel chemistry. The concept of cloning the metagenome to access the collective genomes and the biosynthetic machinery of soil microflora is explored here.

Jo Handelsman; Michelle R. Rondon; Sean F. Brady; Jon Clardy; Robert M. Goodman

1998-01-01

369

Inclusion of soil arsenic bioaccessibility in ecological risk assessment and comparison with biological effects.  

PubMed

The purpose of this study was to conduct an ecological risk assessment (ERA) for meadow voles (Microtus pennslvanicus) found at three arsenic contaminated sites in Nova Scotia, Canada (as well as two background locations) and to compare the numeric results to measured biomarkers of exposure and effect. The daily intake of arsenic by meadow voles was determined by three separate calculations: estimated daily intake (EDI), bioaccessible estimated daily intake (BEDI, with bioaccessibility of soil included), and actual daily intake (ADI, which is calculated with arsenic concentrations in the stomach contents). The median bioaccessibility of arsenic in soils from the contaminated locations was significantly greater than at background locations. The bioaccessible arsenic concentration in soil from all samples (both contaminated and background) was significantly less than the total concentration. Use of site-specific bioaccessibility (hazard quotients=38 at Upper Seal Harbour (USH); 60 at Lower Seal Harbour (LSH); and 120 at Montague tailings (MONT)) and stomach arsenic contents (hazard quotients=2.1 at USH; 7.9 at LSH; and 6.7 at MONT) in the ERA resulted in lower numeric risk than compared to risk calculated with 100% bioavailability (hazard quotient=180 at USH; 75 at LSH; and 680 at MONT). Further, the use of bioaccessibility on the calculation of risk was aligned with biomarker results (changes in glutathione and micronucleated erythrocytes) in voles captured at the sites. This study provides evidence that using site-specific bioaccessibility in ERAs may provide a more realistic level of conservatism, thereby enhancing the accuracy of predicting risk to wildlife receptors. Furthermore, when numeric risk assessments are combined with site-specific biological data (i.e., biomarkers of exposure and effect), both lines of evidence can be used to make informed decisions about ecological risk and site management. PMID:22078367

Saunders, Jared R; Knopper, Loren D; Koch, Iris; Reimer, Kenneth J

2011-12-15

370

Using Soil Available P and Activities of Soil Dehydrogenase and Phosphatase as Indicators for Biodegradation of Organophosphorus Pesticide Methamidophos and Glyphosate  

Microsoft Academic Search

The heavy use of organophosphorus pesticides in northeastern China strongly affects the ecological functions and the quality of the soil environment. In this work, a 30-day soil incubation experiment was conducted to evaluate the potential of using soil available P and the activities of soil dehydrogenase and acid phosphatase as indicators of the application of methamidophos and glyphosate. Two kinds

Ying Yu; Haijun Zhang; Qixing Zhou

2011-01-01

371

Effect of pyrene and cadmium on microbial activity and community structure in soil.  

PubMed

In this study, a greenhouse experiment was conducted to investigate interactive effects of cadmium (Cd) × pyrene × plant treatments on soil microbial activity and community structure. The results demonstrated that the basal respiration, microbial biomass carbon and metabolic quotient in both unplanted and rhizosphere soil were significantly influenced by interaction of Cd and pyrene. The combined application of Cd and pyrene caused a significantly greater biocidal influence on the soil microorganisms than the single spiking of Cd or pyrene. The soil basal respiration increased with the spiking of 2.5 mg kg(-1) Cd in both unplanted and rhizosphere soil. The eco-physiological index of Cd-tolerant populations was significantly different among the unplanted soil, rhizoplane and rhizosphere soil of tall fescue, indicating a slightly uneven distribution of fast- and slow-growing tolerant bacteria. Obvious differences in microbial activity were observed among treatments due to different physicochemical characteristics of the rhizosphere soils depending on the plant species. PMID:23290945

Lu, Mang; Xu, Kui; Chen, Jun

2013-04-01

372

Does powder and granular activated carbon perform equally in immobilizing chlorobenzenes in soil?  

PubMed

The objective of this study is to compare the efficacies of powder activated carbon (PAC) and granular activated carbon (GAC) as amendments for the immobilization of volatile compounds in soil. Soil artificially-spiked with chlorobenzenes (CBs) was amended with either PAC or GAC to obtain an application rate of 1%. The results showed that the dissipation and volatilization of CBs from the amended soil significantly decreased compared to the unamended soil. The bioavailabilities of CBs, which is expressed as butanol extraction and earthworm accumulation, were significantly reduced in PAC and GAC amended soils. The lower chlorinated and hence more volatile CBs experienced higher reductions in both dissipation and bioavailability in the amended soils. The GAC and PAC equally immobilized more volatile CBs in soil. Therefore, it could be concluded that along with environmental implication, applying GAC was the more promising approach for the effective immobilization of volatile compounds in soil. PMID:25406989

Song, Yang; Wang, Fang; Kengara, Fredrick Orori; Bian, Yongrong; Yang, Xinglun; Gu, Chenggang; Ye, Mao; Jiang, Xin

2015-01-23

373

Germination and seed water status of four grasses on moss-dominated biological soil crusts from arid lands  

Microsoft Academic Search

Biological soil crusts dominated by drought-tolerant mosses are commonly found through arid and semiarid steppe communities of the northern Great Basin of North America. We conducted growth chamber experiments to investigate the effects of these crusts on the germination of four grasses: Festuca idahoensis, Festuca ovina, Elymus wawawaiensis and Bromus tectorum. For each of these species, we recorded germination time

Marcelo D. Serpe; Jeanne M. Orm; Tara Barkes; Roger Rosentreter

2006-01-01

374

Long term effects of annual additions of animal manure on soil chemical, physical, and biological properties in the Great Plains  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this study was to determine the effects of long-term annual beef manure amendments and wheat and rye cover crops on selected chemical, physical and biological properties of a typical Midwest U.S. soil under corn silage production. The treatments included: manure application/cover cr...

375

Journal of Integrative Plant Biology 2008, 50 (11): 14061415 Effect of Elevated CO2 and Drought on Soil Microbial  

E-print Network

Journal of Integrative Plant Biology 2008, 50 (11): 1406­1415 Effect of Elevated CO2 and Drought changes, on plant-soil interactions is incomplete. Elevated CO2 effects on C4 plants, though smaller than. Denaturing gradient gel electrophoresis analysis revealed that drought and elevated CO2, singly and combined

Sigler, Von

376

Draft Genome Sequence of Bacillus sp. Strain BSC154, Isolated from Biological Soil Crust of Moab, Utah.  

PubMed

Bacillus sp. BSC154 was isolated from a biological soil crust near Moab, Utah. The strain appears to be capable of chemotaxis and biofilm production. The BSC154 genome contains iron siderophore production, nitrate reduction, mixed acid-butanediol fermentation, and assimilatory and dissimilatory sulfate metabolism pathways. PMID:25395651

Bailey, Alexis C; Kellom, Matthew; Poret-Peterson, Amisha T; Noonan, Kathryn; Hartnett, Hilairy E; Raymond, Jason

2014-01-01

377

Draft Genome Sequence of Massilia sp. Strain BSC265, Isolated from Biological Soil Crust of Moab, Utah.  

PubMed

Massilia sp. BSC265 was isolated from a biological soil crust near Moab, Utah. The strain appears to be capable of chemotaxis and exopolysaccharide synthesis for biofilm adhesion. The BSC265 genome contains a complete dissimilatory nitrate reduction pathway as well as a TCA cycle, making it a facultative anaerobe. PMID:25395652

Bailey, Alexis C; Kellom, Matthew; Poret-Peterson, Amisha T; Noonan, Kathryn; Hartnett, Hilairy E; Raymond, Jason

2014-01-01

378

Draft Genome Sequence of Microvirga sp. Strain BSC39, Isolated from Biological Soil Crust of Moab, Utah.  

PubMed

Microvirga sp. BSC39 was isolated from a biological soil crust near Moab, Utah. The strain appears to be capable of chemotaxis and exopolysaccharide synthesis for biofilm adhesion. The BSC39 genome contains iron siderophore uptake and hydrolysis enzymes; however, it lacks siderophore synthesis pathways, suggesting the uptake of siderophores produced by neighboring microbes. PMID:25395650

Bailey, Alexis C; Kellom, Matthew; Poret-Peterson, Amisha T; Noonan, Kathryn; Hartnett, Hilairy E; Raymond, Jason

2014-01-01

379

Draft Genome Sequence of Massilia sp. Strain BSC265, Isolated from Biological Soil Crust of Moab, Utah  

PubMed Central

Massilia sp. BSC265 was isolated from a biological soil crust near Moab, Utah. The strain appears to be capable of chemotaxis and exopolysaccharide synthesis for biofilm adhesion. The BSC265 genome contains a complete dissimilatory nitrate reduction pathway as well as a TCA cycle, making it a facultative anaerobe. PMID:25395652

Bailey, Alexis C.; Kellom, Matthew; Poret-Peterson, Amisha T.; Noonan, Kathryn; Hartnett, Hilairy E.

2014-01-01

380

STRATIFICATION OF SOIL ORGANIC MATTER AND POTENTIAL IMPACT ON WATER RUNOFF QUALITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil organic matter is a key component of soil quality that sustains many key soil functions by providing the energy, substrates, and biological diversity to support biological activity, which affects (1) aggregation (important for habitat space, oxygen supply, and preventing soil erosion), infiltra...

381

Application of activation techniques to biological analysis. [813 references  

SciTech Connect

Applications of activation analysis in the biological sciences are reviewed for the period of 1970 to 1979. The stages and characteristics of activation analysis are described, and its advantages and disadvantages enumerated. Most applications involve activation by thermal neutrons followed by either radiochemical or instrumental determination. Relatively little use has been made of activation by fast neutrons, photons, or charged particles. In vivo analyses are included, but those based on prompt gamma or x-ray emission are not. Major applications include studies of reference materials, and the elemental analysis of plants, marine biota, animal and human tissues, diets, and excreta. Relatively little use of it has been made in biochemistry, microbiology, and entomology, but it has become important in toxicology and environmental science. The elements most often determined are Ag, As, Au, Br, Ca, Cd, Cl, Co, Cr, Cs, Cu, Fe, Hg, I, K, Mn, Mo, Na, Rb, Sb, Sc, Se, and Zn, while few or no determinations of B, Be, Bi, Ga, Gd, Ge, H, In, Ir, Li, Nd, Os, Pd, Pr, Pt, Re, Rh, Ru, Te, Tl, or Y have been made in biological materials.

Bowen, H.J.M.

1981-12-01

382

Degradation of biochemical activity in soil sterilized by dry heat and gamma radiation  

NASA Technical Reports Server (NTRS)

The effect of soil sterilization by dry heat (0.08% relative humidity), gamma radiation, or both on soil phosphatase, urease, and decarboxylase activity was studied. Soil sterilized by a long exposure to dry heat at relatively low temperatures (eight weeks at 100.5 C) retained higher activities than did soil exposed to a higher temperature (two weeks at 124.5 C), while all activity was destroyed by four days at 148.5 C. Sterilization with 7.5 Mrads destroyed less activity than did heat sterilization. The effect of several individually nonsterizing doses of heat radiation is described.

Shih, K. L.; Souza, K. A.

1978-01-01

383

Carbon Flux and Isotopic Character of Soil and Soil Gas in Stabilized and Active Thaw Slumps in Northwest Alaska  

NASA Astrophysics Data System (ADS)

Permafrost soils store nearly half the world's global carbon. Warming of arctic landscape results in permafrost thaw which causes ground subsidence or thermokarst. On hillslopes, these features rapidly and dramatically alter soil structure, temperature, and moisture, as well as the content and quality of soil organic matter. These changes alter both the rate and mechanism of carbon cycling in permafrost soils, making frozen soils available to both anaerobic and aerobic decomposition. In order to improve our predictive capabilities, we use a chronosequence thaw slumps to examine how fluxes from active and stabilized features differ. Our study site is along the Selawik River in northwest Alaska where a retrogressive thaw slump initiated in the spring of 2004. It has grown to a surface area of 50,000 m2. Products of the erosion are stored on the floor of the feature, trapped on a fan or flushed into the Selawik River. North of slump is undisturbed tundra and adjacent to the west is a slump feature that stabilized and is now covered with a second generation of spruce trees. In this 2 year study, we use measurements of CO2 efflux, ?C13 in soil profiles and CO2 and CH4 abundance to constrain the response of belowground carbon emissions. We also focused on constraining which environmental factors govern C emissions within each of the above ecosystems. To this end, we measured soil temperature, and moisture, abundance and quality of soil organic carbon (SOC), water content, and bulk carbon compositions. Preliminary data from the summer of 2011 suggest that vegetation composition and soil temperature exert the strong control on CO2 efflux. The floor of the active slump and fan are bare mineral soils and are generally 10 to 15°C warmer than the tundra and stabilized slump. Consistently decreasing ?C13 soil gas profiles in the recovered slump confirm that this region is a well-drained soil dominated by C3 vegetation. The ?C13 gas profiles for the tundra, active slump floor, and active fan tend to be more variable as a consequence of less consistently structured soils. This could be due to either the predominance of older carbon being recycled within these profiles or a skewed balance between anaerobic vs. aerobic respiration.

Jensen, A.; Crosby, B. T.; Mora, C. I.; Lohse, K. A.

2012-12-01

384

Uranium accumulation in sandy soil in an arid region due to agricultural activities  

Microsoft Academic Search

\\u000a This work aims at studying the accumulation of uranium in sandy soil in an arid region due to the agricultural activities\\u000a i.e. long time phosphate fertilizer application. Twenty eight soil samples and 14 well water samples were collected from 14\\u000a locations. Two soil samples were collected from each location; one from, 20 years ago, cultivated soil and the other from

Ashraf E. M. Khater; A. S. Al-Saif; H. A. AL-Sewaidan

385

Effects of sorption on biological degradation rates of (2,4-dichlorophenoxy) acetic acid in soils.  

PubMed Central

Three mathematical models were proposed to describe the effects of sorption of both bacteria and the herbicide (2,4-dichlorophenoxy)acetic acid (2,4-D) on the biological degradation rates of 2,4-D in soils. Model 1 assumed that sorbed 2,4-D is not degraded, that only bacteria in solution are capable of degrading 2,4-D in solution, and that sorbed bacteria are not capable of degrading either sorbed or solution 2,4-D. Model 2 stated that only bacteria in the solution phase degrade 2,4-D in solution and that only sorbed bacteria degrade sorbed 2,4-D. Model 3 proposed that sorbed 2,4-D is completely protected from degradation and that both sorbed and solution bacteria are capable of degrading 2,4-D in solution. These models were tested by a series of controlled laboratory experiments. Models 1 and 2 did not describe the data satisfactorily and were rejected. Model 3 described the experimental results quite well, indicating that sorbed 2,4-D was completely protected from biological degradation and that sorbed- and solution-phase bacteria degraded solution-phase 2,4-D with almost equal efficiencies. PMID:3994366

Ogram, A V; Jessup, R E; Ou, L T; Rao, P S

1985-01-01

386

Enzyme activity in terrestrial soil in relation to exploration of the Martian surface  

NASA Technical Reports Server (NTRS)

An exploration was made of enzyme activities in soil, including abundance, persistence and localization of these activities. An attempt was made to develop procedures for the detection and assaying of enzymes in soils suitable for presumptive tests for life in planetary soils. A suitable extraction procedure for soil enzymes was developed and measurements were made of activities in extracts in order to study how urease is complexed in soil organic matter. Mathematical models were developed, based on enzyme action and microbial growth in soil, for rates of oxidation of nitrogen as nitrogen compounds are moved downward in soil by water flow. These biogeochemical models should be applicable to any percolating system, with suitable modification for special features, such as oxygen concetrations, and types of hydrodynamic flow.

Ardakani, M. S.; Mclaren, A. D.; Pukite, A. H.

1972-01-01

387

Effects of biochar and elevated soil temperature on soil microbial activity and abundance in an agricultural system  

NASA Astrophysics Data System (ADS)

As a consequence of Global Warming, rising surface temperatures will likely cause increased soil temperatures. Soil warming has already been shown to, at least temporarily, increase microbial activity and, therefore, the emissions of greenhouse gases like CO2 and N2O. This underlines the need for methods to stabilize soil organic matter and to prevent further boost of the greenhouse gas effect. Plant-derived biochar as a soil amendment could be a valuable tool to capture CO2 from the atmosphere and sequestrate it in soil on the long-term. During the process of pyrolysis, plant biomass is heated in an oxygen-low atmosphere producing the highly stable solid matter biochar. Biochar is generally stable against microbial degradation due to its chemical structure and it, therefore, persists in soil for long periods. Previous experiments indicated that biochar improves or changes several physical or chemical soil traits such as water holding capacity, cation exchange capacity or soil structure, but also biotic properties like microbial activity/abundance, greenhouse gas emissions and plant growth. Changes in the soil microbial abundance and community composition alter their metabolism, but likely also affect plant productivity. The interaction of biochar addition and soil temperature increase on soil microbial properties and plant growth was yet not investigated on the field scale. To investigate whether warming could change biochar effects in soil, we conducted a field experiment attached to a soil warming experiment on an agricultural experimental site near the University of Hohenheim, already running since July 2008. The biochar field experiment was set up as two-factorial randomized block design (n=4) with the factors biochar amendment (0, 30 t ha-1) and soil temperature (ambient, elevated=ambient +2.5° C) starting from August 2013. Each plot has a dimension of 1x1m and is equipped with combined soil temperature and moisture sensors. Slow pyrolysis biochar from the C4 plant Miscanthus was first put on top and then manually incorporated into 20-30 cm soil depth. Differences in the isotopic signature of the biochar and the soil organic matter make it possible to trace the flow of biochar-derived carbon into different labile C pools such as CO2 or microbial biomass. Spring barley litter of the previous growing season was mixed into soil together with the biochar. Rapeseed oil plants were sown one week after biochar application. Weekly gas sampling between the crop rows allows the determination of CO2, N2O and CH4 fluxes. In addition, 13CO2 will be measured at specific dates in order to calculate the proportion of biochar-C in emitted CO2. First soil sampling after biochar application was in November 2013 and soil was taken in three depths (0-5, 5-15 and 15-30 cm). After the first three months we could not observe any effect of biochar on CO2 and N2O emissions, but elevated soil temperature increased emissions of both gases. Data on soil microbial abundance and community composition will be available soon.

Bamminger, Chris; Poll, Christian; Marhan, Sven

2014-05-01

388

Soil Eenzyme Activities and Physical Properties in a Watershed Managed Under Agrogorestry and Row-Crop Systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil aggregate stability and diverse microbial activity influence soil quality, crop growth, nutrient retention, water infiltration, and surface runoff. The objective of the study was to test the hypothesis that permanent vegetative buffers improve selected soil physical properties, which contribu...

389

Biological activities of aqueous extract from Cinnamomum porrectum  

NASA Astrophysics Data System (ADS)

A study was carried out to evaluate biological activities of an extract obtained from Cinnamomum porrectum under reflux using water. Aqueous extract of Cinnamomum porrectum was tested for antibacterial activity against six Gram-positive and eight Gram-negative bacteria as well as MRSA. The results confirmed that the aqueous extract of Cinnamomum porrectum was bactericidal. Cytotoxic tests on Vero cell culture revealed that Cinnamomum porrectum was non-toxic which IC50 value higher than 0.02 mg/mL. Antiviral activity was tested based on the above IC50 values together with the measured EC50 values to obtain Therapeutic Index. The result showed that Cinnamomum porrectum has the ability to inhibit viral replication of HSV-1 in Vero cells.

Farah, H. Siti; Nazlina, I.; Yaacob, W. A.

2013-11-01

390

Effects of nutritional input and diesel contamination on soil enzyme activities and microbial communities in Antarctic soils.  

PubMed

Pollution of Antarctic soils may be attributable to increased nutritional input and diesel contamination via anthropogenic activities. To investigate the effect of these environmental changes on the Antarctic terrestrial ecosystem, soil enzyme activities and microbial communities in 3 types of Antarctic soils were evaluated. The activities of alkaline phosphomonoesterase and dehydrogenase were dramatically increased, whereas the activities of ?-glucosidase, urease, arylsulfatase, and fluorescein diacetate hydrolysis were negligible. Alkaline phosphomonoesterase and dehydrogenase activities in the 3 types of soils increased 3- to 10-fold in response to nutritional input, but did not increase in the presence of diesel contamination. Consistent with the enzymatic activity data, increased copy numbers of the phoA gene, encoding an alkaline phosphomonoesterase, and the 16S rRNA gene were verified using quantitative real-time polymerase chain reaction. Interestingly, dehydrogenase activity and 16S rRNA gene copy number increased slightly after 30 days, even under diesel contamination, probably because of adaptation of the bacterial population. Intact Antarctic soils showed a predominance of Actinobacteria phylum (mostly Pseudonorcarida species) and other phyla such as Proteobacteria, Chloroflexi, Planctomycetes, Firmicutes, and Verrucomicrobia were present in successively lower proportions. Nutrient addition might act as a selective pressure on the bacterial community, resulting in the prevalence of Actinobacteria phylum (mostly Arthrobacter species). Soils contaminated by diesel showed a predominance of Proteobacteria phylum (mostly Phyllobacterium species), and other phyla such as Actinobacteria, Bacteroidetes, Planctomycetes, and Gemmatimonadetes were present in successively lower proportions. Our data reveal that nutritional input has a dramatic impact on bacterial communities in Antarctic soils and that diesel contamination is likely toxic to enzymes in this population. PMID:23274977

Han, Jiwon; Jung, Jaejoon; Hyun, Seunghun; Park, Hyun; Park, Woojun

2012-12-01

391

Primary succession of soil enzyme activity and heterotrophic microbial communities along the chronosequence of Tianshan Mountains No. 1 Glacier, China.  

PubMed

We investigated the primary successions of soil enzyme activity and heterotrophic microbial communities at the forefields of the Tianshan Mountains No. 1 Glacier by investigating soil microbial processes (microbial biomass and nitrogen mineralization), enzyme activity and community-level physiological profiling. Soils deglaciated between 1959 and 2008 (0, 5, 17, 31 and 44 years) were collected. Soils >1,500 years in age were used as a reference (alpine meadow soils). Soil enzyme activity and carbon-source utilization ability significantly increased with successional time. Amino-acid utilization rates were relatively higher in early, unvegetated soils (0 and 5 years), but carbohydrate utilization was higher in later stages (from 31 years to the reference soil). Discriminant analysis, including data on microbial processes and soil enzyme activities, revealed that newly exposed soils (0-5 years) and older soils (17-44 years) were well-separated from each other and obviously different from the reference soil. Correlation analysis revealed that soil organic carbon, was the primary factor influencing soil enzyme activity and heterotrophic microbial community succession. Redundancy analysis suggested that soil pH and available P were also affect microbial activity to a considerable degree. Our results indicated that glacier foreland soils have continued to develop over 44 years and soils were significantly affected by the geographic location of the glacier and the local topography. Soil enzyme activities and heterotrophic microbial communities were also significantly influenced by these variables. PMID:25472706

Zeng, Jun; Wang, Xiao-Xia; Lou, Kai; Eusufzai, Moniruzzaman Khan; Zhang, Tao; Lin, Qing; Shi, Ying-Wu; Yang, Hong-Mei; Li, Zhong-Qing

2015-02-01

392

Ecological Maturity and Drought Stress of Biological Soil Crusts along a Central European Inland Dune Catena  

NASA Astrophysics Data System (ADS)

In the early stages of ecological succession, the rate of primary production, or total photosynthesis (P) exceeds the rate of community respiration (R), so that the P/R ratio is greater than 1. In the special case of organic pollution, the P/R ratio is typically less than 1. Odums theory (Odum, 1969) is that P/R approaches 1 as succession occurs. The P/R ratio, therefore, should be an excellent functional index of the relative maturity of the system. Photosynthesis and respiration of biological soil crusts (BSCs) sampled along a mobile inland dune catena were determined to evaluate the applicability of Odums P/R ratio for estimation of crust ecosystem maturity under progressing drought stress. Samples of BSCs were collected near the dune crest (aeolian deflation zone, BSC type 1, thickness 1-2 mm, 13.8 mg/m2 Chlorophyll a), at the at the dune slope (protected from wind by tussocks of Corynephorus canescens, BSC type 2, thickness 2-4 mm, 24.5 mg/m2 Chlorophyll a) and near the base (BSC type 3, thickness 4-6 mm, 27.3 mg/m2 Chlorophyll a) of a carbonate-free, siliceous, east-facing inland dune. The P/R-ratio decreased with crust biomass downslope, with the exception that the highly disturbed and seemingly most immature BSC type 1 did not have the highest P/R ratio as could be expected according to our working hypothesis (mean arithmetic P/R=0.85), but the lowest compared to BSC types 2 and 3 (mean arithmetic P/R values 1.78 and 1.25, respectively). Dümig et al. (2013) reported decreasing relative amounts of fossil and increasing amounts of recent carbon downslope for the same BSCs as studied here. At the same time, the 14C ages of the crusts decreased from 570 years for the mineral substrate, to 165, 80 and ~5 years for BSC type 1, 2 and 3, respectively (Dümig et al., 2013). We attribute the unexpectedly low P/R ratio of crust 1 to the influence of fossil, non-crust organic matter which was inherited from former pedogenesis, and which can be considered as "organic pollution" in the Odum's sense. Decomposition of inherited organic matter possibly superimposed decomposition of the ecosystem's recent C, thus lowering P/R. Soil water potential did not significantly influence the P/R ratio, indicating that the maturity can be compared between different BSC types under varying soil moisture conditions. References Dümig, A., Veste, M., Hagedorn, F., Fischer, T., Lange, P., Spröte, R., Kögel-Knabner, I., 2013. Biological soil crusts on initial soils: organic carbon dynamics and chemistry under temperate climatic conditions. Biogeosciences Discuss. 10, 851-894. Odum, E.P., 1969. The strategy of ecosystem development. Science 164, 262-270.

Fischer, Thomas; Veste, Maik; Mykhailova, Larysa

2014-05-01

393

Functional profiles reveal unique ecological roles of various biological soil crust organisms  

USGS Publications Warehouse

1. At the heart of the body of research on biodiversity effects on ecosystem function is the debate over whether different species tend to be functionally singular or redundant. When we consider ecosystem multi-function, the provision of multiple ecosystem functions simultaneously, we may find that seemingly redundant species may in fact play unique roles in ecosystems. 2. Over the last few decades, the significance of biological soil crusts (BSCs) as ecological boundaries and ecosystem engineers, and their multi-functional nature, has become increasingly well documented. We compiled 'functional profiles' of the organisms in this understudied community, to determine whether functional singularity emerges when multiple ecosystem functions are considered. 3. In two data sets, one representing multiple sites around the semi-arid regions of Spain (regional scale), and another from a single site in central Spain (local scale), we examined correlations between the abundance or frequency of BSC species in a community, and multiple surrogates of ecosystem functioning. There was a wide array of apparent effects of species on specific functions. 4. Notably, in gypsiferous soils and at regional scale, we found that indicators of carbon (C) and phosphorus cycling were apparently suppressed and promoted by the lichens Diploschistes diacapsis and Squamarina lentigera, respectively. The moss Pleurochaete squarrosa appears to promote C cycling in calcareous soils at this spatial scale. At the local scale in gypsiferous soils, D. diacapsis positively correlated with carbon cycling, but negatively with nitrogen cycling, whereas numerous lichens exhibited the opposite profile. 5. We found a high degree of functional singularity, i.e. that species were highly individualistic in their effects on multiple functions. Many functional attributes were not easily predictable from existing functional grouping systems based primarily on morphology. 6. Our results suggest that maintaining species-rich BSC communities is crucial to maintain the overall functionality of ecosystems dominated by these organisms, and that dominance and the outcome of competition could be highly influential in the determination of such functionality. ?? 2011 The Authors. Functional Ecology ?? 2011 British Ecological Society.

Bowker, M.A.; Mau, R.L.; Maestre, F.T.; Escolar, C.; Castillo-Monroy, A. P.

2011-01-01

394

Influence of the activity of Allobophora molleri in microbial activity and metal availability of arsenic-polluted soils.  

PubMed

We investigate the use of Allolobophora molleri as a biomarker of arsenic (As)-polluted soils and study the influence of A. molleri on the metabolic activity and microbial biodiversity of soil polluted with As. Because there are no experimental data available regarding the effect of the pollutant rate of As on A. molleri, we determined the LC?? that was 143.5 mg As kg(-1). Sodium arsenite was added at two rates, equivalent to 143.5 and 71.8 mg As kg(-1) soil, to a soil that was then maintained with and without worms for 120 days. In addition, a nonpolluted soil without and with earthworms was used as the control. The As concentration in the soil was measured after 7 and 120 and the worm weight and As concentration after 120 days of exposure. Soil enzymatic activities and the structure of the soil microbial community, by analysis of phospholipid fatty acids, were determined. At the end of the experiment, the highest earthworm As contents were found in soils polluted with the highest rate of As. Earthworm weights significantly decreased in soil polluted with 143.5 or 71.8 mg As kg(-1), by 49.9 and 29.8% of initial weight, because the worm consumption rate decreased. These results suggest that A. molleri can be used as a good biomarker of the As toxicity. The As available fraction decreased in polluted soil with worms because the metal was accumulated in worm tissues. However, this assimilation was lower than other worms such as L. rubbellus or L. terrestris. Soil enzymatic activities were decreased in As-polluted soils but were increased significantly by the presence of earthworms. The earthworms modified the soil microbial diversity. In this respect, A. molleri significantly increased (p < 0.05) the bacterial and fungal populations. Soil As pollution decreased microbial biodiversity but to a lesser extent in the presence of A. molleri. PMID:23703122

Tejada, Manuel; Gómez, Isidoro; Hernández, Teresa; García, Carlos

2013-10-01

395

Transformation of heavy metal fractions on soil urease and nitrate reductase activities in copper and selenium co-contaminated soil.  

PubMed

This study aims to explore the effects of the distribution, transformation and bioavailability of different fractions of copper (Cu) and selenium (Se) in co-contaminated soils on soil enzymes, providing references for the phytoremediation of contaminated areas and agriculture environmental protection. Pot experiments and laboratory analysis were used to investigate the transformation and bioavailability of additional Cu and Se for pakchoi (Brassica chinensis) in co-contaminated soil. In the uncontaminated soil, Cu mainly existed in residual form, whereas Se was present in residual form and in elemental and organic-sulfide matter-bound form. In the contaminated soil, Cu mainly bound to Fe-Mn oxidates, whereas Se was in exchangeable and carbonates forms. After a month of pakchoi growth, Cu tended to transfer into organic matter-bound fractions, whereas Se tended to bound to Fe-Mn oxidates. The IR (reduced partition index) value of Cu decreased as the concentrations of Cu and Se gradually increased, whereas the IR value of Se decreased as the concentration of Se increased. The IR value before pakchoi planting and after it was harvested was not affected by the concentration of exogenous Cu. Soil urease and nitrate reductase activities were inhibited by Cu and Se pollution either individually or combined in different degrees, following the order nitrate reductase>urease. The significant correlation between the IR value and soil enzyme activities suggests that this value could be used to evaluate the bioavailability of heavy metals in soil. Path analysis showed that the variations in exchangeable Cu and organic-sulfide matter-bound and elemental Se had direct effects on the activities of the two enzymes, suggesting their high bioavailability. Therefore, the IR value and the transformation of metals in soil could be used as indicators in evaluating the bioavailability of heavy metals. PMID:25193883

Hu, Bin; Liang, Dongli; Liu, Juanjuan; Lei, Lingming; Yu, Dasong

2014-12-01

396

[Mineralization of soil organic carbon and its relationship with soil enzyme activities in apple orchard in Weibei].  

PubMed

A total of 36 kinds of soil samples were collected from apple orchards under three kinds of management model, including clear tillage model, intercropping white clover model and intercropping small crown flower model, the mineralization of soil organic carbon and four kinds of soil enzymes activities were determined, and the relationship between the two parameters was also analyzed. The results showed that the soil organic carbon mineralization of all the three treatments was almost the same. The daily SOC mineralization rate first increased and then decreased, and finally tended to be stable. After 31 days incubation experiment, the maximum accumulative amount of SOC mineralization occurred in white clover treatment with 590 mg x kg(-1), followed by small crown flower treatment with 541 mg x kg(-1), and the minimum value was 367 mg x kg(-1) in the control treatment, and the accumulative amount of SOC mineralization decreased with increasing soil depth. Discovered by the first-order kinetics, the fitting parameter Cp value ranged from 0.252 to 2.74 g x kg(-1) and k value ranged from 0.019 to 0.051 d(-1), and the two grass treatments both showed significant difference in Cp value from the control treatment, and the soil invertase and cellulose activities showed obvious relationship with soil organic carbon mineralization. PMID:25244868

Jia, Man-Li; Guo, Hong; Li, Hui-Ke

2014-07-01

397

Preparation of Biologically Active Subcellular Fractions Using the Balch Homogenizer  

PubMed Central

Obtaining vesicular fractions from cell lines or animal tissue is both time and technically intensive. The presence of plasma membrane and nuclear contaminants within a preparation is often dependent upon the method of homogenization and is usually mitigated through the use of density gradients. We have developed a method that utilizes Balch homogenization and differential centrifugation to obtain two distinct vesicular fractions along with purified nuclear, cytoplasmic and ghost fractions within a three hour period of time without the use of density gradients. Importantly, these fractions maintain their biologic activity following isolation and may be used for both localization and biochemical analyses. PMID:19622341

German, Christopher L; Howe, Charles L

2009-01-01

398

Recent developments in biological activities of chalcones: a mini review.  

PubMed

Chalcones represent key structural motif in the plethora of biologically active molecules including synthetic and natural products. Synthetic manipulations of chalcones or their isolation from natural sources are being investigated worldwide for the development of more potent and efficient drugs for the treatment of several dreadful diseases such as cancer, diabetes, HIV, tuberculosis, malaria etc. Over the past few years, a large volume of research papers and review articles highlighting the significance of chalcone derivatives has been compiled in the literature. The present review article focuses on the recent developments (2010-2014) on various pharmacological and medicinal aspects of chalcones and their analogues. PMID:25137491

Singh, Parvesh; Anand, Amit; Kumar, Vipan

2014-10-01

399

Functionalization of hydroxyl terminated polybutadiene with biologically active fluorescent molecule  

Microsoft Academic Search

A biologically active molecule, 2-chloro-4,6-bis(dimethylamino)-1,3,5-triazine (CBDT), has been covalently attached at the terminal carbon atoms of the hydroxyl terminated\\u000a polybutadiene (HTPB) backbone. The modification of HTPB backbone by CBDT molecule does not affect the unique physico-chemical\\u000a properties such as fluidity, hydroxyl value and microstructure of the parent HTPB. The formation of hydrogen bonding between\\u000a the terminal hydroxyl groups and the

R. Murali Sankar; Subhadeep Saha; K. Seeni Meera; Tushar Jana

2009-01-01

400

NASA's Soil Moisture Active and Passive (SMAP) Mission  

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 Decadal Survey. SMAP will make global measurements of soil moisture at the Earth's land surface and its freeze-thaw state. These measurements will allow significantly improved estimates of water, energy and carbon transfers between the land and atmosphere. Soil moisture measurements are also of great importance in assessing flooding and monitoring drought. Knowledge gained from SMAP observations can help mitigate these natural hazards, resulting in potentially great economic and social benefits. SMAP observations of soil moisture and freeze/thaw timing over the boreal latitudes will also reduce a major uncertainty in quantifying the global carbon balance and help to resolve an apparent missing carbon sink over land. The SMAP mission concept will utilize an L-band radar and radiometer sharing a rotating 6-meter mesh reflector antenna flying in a 680 km polar orbit with an 8-day exact ground track repeat aboard a 3-axis stabilized spacecraft to provide high-resolution and high-accuracy global maps of soil moisture and freeze/thaw state every two to three days. In addition, the SMAP project will use these surface observations with advanced modeling and data assimilation to provide estimates of deeper root-zone soil moisture and net ecosystem exchange of carbon. SMAP recently completed its Phase A Mission Concept Study Phase for NASA and transitioned into Phase B (Formulation and Detailed Design). A number of significant accomplishments occurred during this initial phase of mission development. The SMAP project held several open meetings to solicit community feedback on possible science algorithms, prepared preliminary draft Algorithm Theoretical Basis Documents (ATBDs) for each mission science product, and established a prototype algorithm testbed to enable testing and evaluation of the performance of candidate algorithms. SMAP conducted an Applications Workshop in September 2009 to coordinate with potential application users interested in the mission data. A draft Applications Plan describing the Project s planned outreach to potential applications users has been prepared and will be updated during Phase B. SMAP made a significant evaluation of the potential terrestrial radio frequency interference (RFI) source environment and established radiometer and radar flight hardware and ground processing mitigation approaches. SMAP finalized its science orbit and orbit injection approach to optimize launch mass and prepared launch and commissioning scenarios and timeline. A science data communications approach was developed to maximize available science data volume to improve science margins while maintaining moderately short data product latencies to support many potential applications using existing ground assets and with minimum impact to the flight system. SMAP developed rigid multi-body and flexible body dynamics and control models and system designs for the 6-meter rotating instrument reflector-boom assembly (RBA) and flight system to confirm pointing and control performance, and devised strategies to efficiently implement on-orbit balancing if needed. Industry partners were selected for the spin mechanism assembly (SMA) and RBA. Preliminary designs for the radar and radiometer were initiated, including constructing breadboards of key assemblies.

Kellogg, Kent; Njoku, Eni; Thurman, Sam; Edelstein, Wendy; Jai, Ben; Spencer, Mike; Chen, Gun-Shing; Entekhabi, Dara; O'Neill, Peggy; Piepmeier, Jeffrey; Brown, Molly; Savinell, Chris; Entin, Jared; Ianson, Eric

2010-01-01

401

Soil carbon, microbial activity and nitrogen availability in agroforestry systems on moderately alkaline soils in northern India  

Microsoft Academic Search

The present investigation aimed to analyze the role of agroforestry systems in improving soil organic matter status, microbial activity and nitrogen availability with a view to effective management of the fertility of moderately alkaline soils. The study site was located at Karnal (29°59?N, 76°51?E, 250m.s.l.) and the systems were characterized by a rice–berseem crop rotation; agrisilvicultural systems of Acacia, Eucalyptus

B. Kaur; S. R. Gupta; G. Singh

2000-01-01

402

I. Spatio-temporal patterns of soil microbial and enzymatic activities in an agricultural soil  

Microsoft Academic Search

In the general context of the search of a quality index for soil as an indicator of sustainable management, we analyzed a soil recently subjected to agriculture from the “El Salado” river basin (Buenos Aires, Argentina) under no-till or conventional tillage (CT). We sought to detect whether a pattern of interactions among microbial, biochemical and physico-chemical variables in soil exists

M. A Aon; M. N Cabello; D. E Sarena; A. C Colaneri; M. G Franco; J. L Burgos; S Cortassa

2001-01-01

403

Changes in the enzymatic activity of soil samples upon their storage  

NASA Astrophysics Data System (ADS)

The influence of the duration and conditions of storage of soil samples on the activity of soil enzymes (catalase, ?-fructofuranosidase, and dehydrogenase) was studied for the main soils of southern Russia (different subtypes of chernozems, chestnut soils, brown forest soils, gray forest s