De novo prediction of the genomic components and capabilities for microbial plant biomass degradation from (meta-)genomes

PubMed Central

2013-01-01

Background Understanding the biological mechanisms used by microorganisms for plant biomass degradation is of considerable biotechnological interest. Despite of the growing number of sequenced (meta)genomes of plant biomass-degrading microbes, there is currently no technique for the systematic determination of the genomic components of this process from these data. Results We describe a computational method for the discovery of the protein domains and CAZy families involved in microbial plant biomass degradation. Our method furthermore accurately predicts the capability to degrade plant biomass for microbial species from their genome sequences. Application to a large, manually curated data set of microbial degraders and non-degraders identified gene families of enzymes known by physiological and biochemical tests to be implicated in cellulose degradation, such as GH5 and GH6. Additionally, genes of enzymes that degrade other plant polysaccharides, such as hemicellulose, pectins and oligosaccharides, were found, as well as gene families which have not previously been related to the process. For draft genomes reconstructed from a cow rumen metagenome our method predicted Bacteroidetes-affiliated species and a relative to a known plant biomass degrader to be plant biomass degraders. This was supported by the presence of genes encoding enzymatically active glycoside hydrolases in these genomes. Conclusions Our results show the potential of the method for generating novel insights into microbial plant biomass degradation from (meta-)genome data, where there is an increasing production of genome assemblages for uncultured microbes. PMID:23414703

Can post-wildfire Burned Area Emergency Response treatments mitigate watershed degradation?

NASA Astrophysics Data System (ADS)

Neary, D.; Ffolliott, P.; Bautista, S.; Wittenberg, L.

2009-04-01

Wildfire is a natural phenomenon that began with the development of terrestrial vegetation in a lightning-filled atmosphere 350 million years ago. As human populations developed in the Pleistocene and Holocene epochs, mankind transformed fire into one of its oldest tools. A negative impact of prime concern in the 21st Century is desertification. This term refers to land degradation, not the immediate creation of classical deserts. It is about the loss of the land's proper hydrologic function and biological productivity as a result of human activities and climate change. It affects 33% of the earth's surface and over a billion people. Fire-related desertification has a number of environmental, social, and economic consequences. The two key environmental consequences are soil erosion and exotic plant invasions. Wildfires typically have exotic plant species abundances ten times that of undisturbed forests (Neary et al. 2003). Seeding has been used for many years in the USA as a prime Burned Area Emergency Response (BAER) treatment. Until recently, this seeding contributed to exotic plant invasions since fast-growing, but non native plants seeds were used. The use of native plant seeds and sterile hybrids has reduced this problem somewhat. Erosion after wildfires documented in the USA can be in the range of <1 to 370 Mg/ha, depending on fire severity, degree of water repellency, slope, and post-fire rainfall events. Soil losses in the high end of that range definitely exceed soil loss tolerances and contribute to desertification. Soil disturbance and degradation after wildfires is a function of fire severity, and the impacts can range from the minimal to catastrophic and long-lasting. The most obvious impact is the loss of organic matter from combustion of the forest floor. Changes in soil physical and chemical properties with high-severity wildfire can produce water repellency, aggravating rainfall runoff and erosion. Since soils take long times to form (50 to 75

Understanding how the complex molecular architecture of mannan-degrading hydrolases contributes to plant cell wall degradation.

PubMed

Zhang, Xiaoyang; Rogowski, Artur; Zhao, Lei; Hahn, Michael G; Avci, Utku; Knox, J Paul; Gilbert, Harry J

2014-01-24

Microbial degradation of plant cell walls is a central component of the carbon cycle and is of increasing importance in environmentally significant industries. Plant cell wall-degrading enzymes have a complex molecular architecture consisting of catalytic modules and, frequently, multiple non-catalytic carbohydrate binding modules (CBMs). It is currently unclear whether the specificities of the CBMs or the topology of the catalytic modules are the primary drivers for the specificity of these enzymes against plant cell walls. Here, we have evaluated the relationship between CBM specificity and their capacity to enhance the activity of GH5 and GH26 mannanases and CE2 esterases against intact plant cell walls. The data show that cellulose and mannan binding CBMs have the greatest impact on the removal of mannan from tobacco and Physcomitrella cell walls, respectively. Although the action of the GH5 mannanase was independent of the context of mannan in tobacco cell walls, a significant proportion of the polysaccharide was inaccessible to the GH26 enzyme. The recalcitrant mannan, however, was fully accessible to the GH26 mannanase appended to a cellulose binding CBM. Although CE2 esterases display similar specificities against acetylated substrates in vitro, only CjCE2C was active against acetylated mannan in Physcomitrella. Appending a mannan binding CBM27 to CjCE2C potentiated its activity against Physcomitrella walls, whereas a xylan binding CBM reduced the capacity of esterases to deacetylate xylan in tobacco walls. This work provides insight into the biological significance for the complex array of hydrolytic enzymes expressed by plant cell wall-degrading microorganisms.

Interconnections between mRNA degradation and RDR-dependent siRNA production in mRNA turnover in plants.

PubMed

Tsuzuki, Masayuki; Motomura, Kazuki; Kumakura, Naoyoshi; Takeda, Atsushi

2017-03-01

Accumulation of an mRNA species is determined by the balance between the synthesis and the degradation of the mRNA. Individual mRNA molecules are selectively and actively degraded through RNA degradation pathways, which include 5'-3' mRNA degradation pathway, 3'-5' mRNA degradation pathway, and RNA-dependent RNA polymerase-mediated mRNA degradation pathway. Recent studies have revealed that these RNA degradation pathways compete with each other in mRNA turnover in plants and that plants have a hidden layer of non-coding small-interfering RNA production from a set of mRNAs. In this review, we summarize the current information about plant mRNA degradation pathways in mRNA turnover and discuss the potential roles of a novel class of the endogenous siRNAs derived from plant mRNAs.

Behavior of N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA) in biosolids amended soil-plant microcosms of seven plant species: Accumulation and degradation.

PubMed

Wen, Bei; Pan, Ying; Shi, Xiaoli; Zhang, Hongna; Hu, Xiaoyu; Huang, Honglin; Lv, Jitao; Zhang, Shuzhen

2018-06-13

Perfluorooctane sulfonate (PFOS) precursors have been found extensively in sewage sludge and biosolids-amended soils. The degradation of these precursors are regarded as a significant source of PFOS in the environment. In this study, the accumulation of N-ethyl perfluorooctane sulfonamido acetic acid (N-EtFOSAA) in the plants of seven species, namely alfalfa, lettuce, maize, mung bean, radish, ryegrass, and soybean from biosolids-amended soil, and the degradation kinetics of N-EtFOSAA in soil-plant microcosms were evaluated over 60 days. N-EtFOSAA was found in the roots of all plant species, while was not in stems and leaves. The root concentration factors of N-EtFOSAA ranged 0.52-1.37 (pmol/g root )/(pmol/g soil ). Stepwise multiple regression analysis was used to elucidate the accumulation of N-EtFOSAA in the roots of plants. The results showed that the root protein and lipid contents explain 85.0% of the variation in root N-EtFOSAA levels (P < 0.05). Four degradation products, including N-ethyl perfluorooctane sulfonamide (N-EtFOSA), perfluorooctane sulfonamide acetate (FOSAA), perfluorooctane sulfonamide (FOSA) and PFOS were found in soils and plant roots, stems and leaves, indicating the degradation of N-EtFOSAA in soil-plant system. Degradation kinetics fitted a first-order kinetic model well. Degradation rate constants of N-EtFOSAA in the microcosms with plants ranged 0.063-0.165 d -1 , which was 1.40-3.6 times higher than those without plants. Degradation rate constant of maize was relatively higher than those of other plant species. The results is the first to reveal N-EtFOSAA accumulation in plants and degradation in soil-plant microcosms. Copyright © 2018. Published by Elsevier B.V.

Role of proteolytic enzymes in degradation of plant tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewosz, J.; Kelman, A.; Sequeira, L.

1991-01-01

Strain SR 394 of Erwinia carotovora (Ecc) produced proteases constitutively in all media tested. Growth of Ecc and production of protease were enhanced significantly by the presence of poetic materials and/or plant call walls in the test media. After electrofocusing, one major and one minor protease bands, at PI 4.8 and PI 5.1, respectively, were detected. Only one band of 43 kDa was detected on SDS gels. Only one protease band was detected in SDS gels of infected plant extracts. This protease was purified to homogeneity. It in a highly thermostable metal protease; it degrades gelatin, soluble collagen and hidemore » powderazure, shows weak activity on casein and azocasein, but does not degrade insoluble collagen or elastin.« less

Hydrocarbon degradation and plant colonization of selected bacterial strains isolated from the rhizsophere and plant interior of Italian ryegrass and Birdsfoot trefoil

NASA Astrophysics Data System (ADS)

Sohail, Y.; Andria, V.; Reichenauer, T. G.; Sessitsch, A.

2009-04-01

Hydrocarbon-degrading strains were isolated from the rhizosphere, root and shoot interior of Italian ryegrass (Lolium multiflorum var. Taurus), Birdsfoot trefoil (Lotus corniculatus var. Leo) grown in a soil contaminated with petroleum oil. Strains were tested regarding their phylogeny and their degradation efficiency. The most efficient strains were tested regarding their suitability to be applied for phytoremediation of diesel oils. Sterilized and non-sterilized agricultural soil, with and with out compost, were spiked with diesel and used for planting Italian ryegrass and birdsfoot trefoil. Four selected strains with high degradation activities, derived from the rhizosphere and plant interior, were selected for individual inoculation. Plants were harvested at flowering stage and plant biomass and hydrocarbon degradation was determined. Furthermore, it was investigated to which extent the inoculant strains were able to survive and colonize plants. Microbial community structures were analysed by 16S rRNA and alkB gene analysis. Results showed efficient colonization by the inoculant strains and improved degradation by the application of compost combined with inoculation as well as on microbial community structures will be presented.

Uncovering the abilities of Agaricus bisporus to degrade plant biomass throughout its life cycle.

PubMed

Patyshakuliyeva, Aleksandrina; Post, Harm; Zhou, Miaomiao; Jurak, Edita; Heck, Albert J R; Hildén, Kristiina S; Kabel, Mirjam A; Mäkelä, Miia R; Altelaar, Maarten A F; de Vries, Ronald P

2015-08-01

The economically important edible basidiomycete mushroom Agaricus bisporus thrives on decaying plant material in forests and grasslands of North America and Europe. It degrades forest litter and contributes to global carbon recycling, depolymerizing (hemi-)cellulose and lignin in plant biomass. Relatively little is known about how A. bisporus grows in the controlled environment in commercial production facilities and utilizes its substrate. Using transcriptomics and proteomics, we showed that changes in plant biomass degradation by A. bisporus occur throughout its life cycle. Ligninolytic genes were only highly expressed during the spawning stage day 16. In contrast, (hemi-)cellulolytic genes were highly expressed at the first flush, whereas low expression was observed at the second flush. The essential role for many highly expressed plant biomass degrading genes was supported by exo-proteome analysis. Our data also support a model of sequential lignocellulose degradation by wood-decaying fungi proposed in previous studies, concluding that lignin is degraded at the initial stage of growth in compost and is not modified after the spawning stage. The observed differences in gene expression involved in (hemi-)cellulose degradation between the first and second flushes could partially explain the reduction in the number of mushrooms during the second flush. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Assessment of soil ecosystem in degraded areas of vineyards after organic treatments

NASA Astrophysics Data System (ADS)

Landi, Silvia; D'Errico, Giada; Gagnarli, Elena; Simoni, Sauro; Goggioli, Donatella; Guidi, Silvia; D'Avino, Lorenzo; Lagomarsino, Alessandra; Valboa, Giuseppe; Castaldini, Maurizio; Elio Agnelli, Alessandro; Fantappiè, Maria; Lorenzetti, Romina; Priori, Simone; Costantini, Edoardo A. C.

2017-04-01

(2013), in order to gather data on decomposition rate and litter stabilisation by using commercially available tea bags as standardised test kits. The extraction of nematodes and microarthropods were performed by the Bermann method and the Berlese-Tullgren selector, respectively. The biological soil quality was evaluated by the Maturity Index of nematodes (MI) and Biological Soil Quality index of microarthropods (QBSar). The results from soil sampling before restoring showed significantly lower values of SOC and TN in degraded areas, but no significant differences between degraded and non-degraded areas for enzymes, QBSar, nematode abundance and MI. Fontodi farm, under organic management since many years, showed significantly higher abundance of microarthropods, nematodes and enzymes than San Disdagio farm. The application of restoration techniques in 2016 showed a significant increase of TOC and TN only under compost addition treatment. As regards microarthropod communities, all the treatments showed a sensible increase in abundance and the conservation of high QBSar values. All the treatments increased the fungal feeder activity of nematodes and decreased the number of plant parasitic nematodes taxa. The major pest of grapes, the virus-vector Xiphinema index (Longidoridae), disappeared in the treated plots, whereas it remained in the control plots.

Resource-use efficiencies of three indigenous tree species planted in resource islands created by shrubs: implications for reforestation of subtropical degraded shrublands

Treesearch

Nan Liu; Qinfeng Guo

2012-01-01

Shrub resource islands are characterized by resources accumulated shrubby areas surrounded by relative barren soils. This research aims to determine resource-use efficiency of native trees species planted on shrub resource islands, and to determine how the planted trees may influence the resource islands in degraded shrublands in South China. Shrub (Rhodomyrtus...

Remediation of blowouts by clonal plants in Maqu degraded alpine grasslands of northwest China.

PubMed

Kang, JianJun; Zhao, WenZhi; Zhao, Ming

2017-03-01

The sand-fixation of plants is considered to be the most effective and fundamental measure in desertification control in many arid and semi-arid regions. Carex brunnescens (Carex spp) and Leymus secalinus (Leymus), two perennial clonal herbs native to the Maqu degraded alpine areas of northwest China, are dominant and constructive species in active sand dunes that have excellent adaptability to fix sand dunes found to date. In order to study the ability and mechanism of sandland blowout remediation by two clone plants C. brunnescens and L. secalinus, the artificially emulated blowouts were set up in the populations of two clonal plants in the field. The results showed that both C. brunnescens and L. secalinus produced more new ramets in the artificially emulated blowouts than in the natural conditions, suggesting that the two clonal plants had strong ability in blowouts remediation; while the biomass, number of leaves and height of new ramets in the artificially emulated blowouts were less than in the natural conditions due to the restriction of poor nutrients in the artificially emulated blowouts. The ability of blowouts remediation by C. brunnescens was stronger than L. secalinus, as it generated more new ramets than L. secalinus in the process of blowouts remediation. The new ramets of L. secalinus in the blowouts remediation were mainly generated by the buds in the rhizomes which spread from outside of the blowouts; while those of C. brunnescens were generated both by the buds in the rhizomes which spread from outside, and by the buds in the rhizomes inside which were freed from dormancy in the deeper soil under wind erosion conditions. These findings suggest that through rapid clonal expansion capability, C. brunnescens and L. secalinus exhibited strong ability in blowouts remediation which can be one of the most effective strategies to restore and reconstruct degraded vegetations in Maqu alpine areas of northwest China.

Efficient plant biomass degradation by thermophilic fungus Myceliophthora heterothallica.

PubMed

van den Brink, Joost; van Muiswinkel, Gonny C J; Theelen, Bart; Hinz, Sandra W A; de Vries, Ronald P

2013-02-01

Rapid and efficient enzymatic degradation of plant biomass into fermentable sugars is a major challenge for the sustainable production of biochemicals and biofuels. Enzymes that are more thermostable (up to 70°C) use shorter reaction times for the complete saccharification of plant polysaccharides compared to hydrolytic enzymes of mesophilic fungi such as Trichoderma and Aspergillus species. The genus Myceliophthora contains four thermophilic fungi producing industrially relevant thermostable enzymes. Within this genus, isolates belonging to M. heterothallica were recently separated from the well-described species M. thermophila. We evaluate here the potential of M. heterothallica isolates to produce efficient enzyme mixtures for biomass degradation. Compared to the other thermophilic Myceliophthora species, isolates belonging to M. heterothallica and M. thermophila grew faster on pretreated spruce, wheat straw, and giant reed. According to their protein profiles and in vitro assays after growth on wheat straw, (hemi-)cellulolytic activities differed strongly between M. thermophila and M. heterothallica isolates. Compared to M. thermophila, M. heterothallica isolates were better in releasing sugars from mildly pretreated wheat straw (with 5% HCl) with a high content of xylan. The high levels of residual xylobiose revealed that enzyme mixtures of Myceliophthora species lack sufficient β-xylosidase activity. Sexual crossing of two M. heterothallica showed that progenies had a large genetic and physiological diversity. In the future, this will allow further improvement of the plant biomass-degrading enzyme mixtures of M. heterothallica.

Efficient Plant Biomass Degradation by Thermophilic Fungus Myceliophthora heterothallica

PubMed Central

van den Brink, Joost; van Muiswinkel, Gonny C. J.; Theelen, Bart; Hinz, Sandra W. A.

2013-01-01

Rapid and efficient enzymatic degradation of plant biomass into fermentable sugars is a major challenge for the sustainable production of biochemicals and biofuels. Enzymes that are more thermostable (up to 70°C) use shorter reaction times for the complete saccharification of plant polysaccharides compared to hydrolytic enzymes of mesophilic fungi such as Trichoderma and Aspergillus species. The genus Myceliophthora contains four thermophilic fungi producing industrially relevant thermostable enzymes. Within this genus, isolates belonging to M. heterothallica were recently separated from the well-described species M. thermophila. We evaluate here the potential of M. heterothallica isolates to produce efficient enzyme mixtures for biomass degradation. Compared to the other thermophilic Myceliophthora species, isolates belonging to M. heterothallica and M. thermophila grew faster on pretreated spruce, wheat straw, and giant reed. According to their protein profiles and in vitro assays after growth on wheat straw, (hemi-)cellulolytic activities differed strongly between M. thermophila and M. heterothallica isolates. Compared to M. thermophila, M. heterothallica isolates were better in releasing sugars from mildly pretreated wheat straw (with 5% HCl) with a high content of xylan. The high levels of residual xylobiose revealed that enzyme mixtures of Myceliophthora species lack sufficient β-xylosidase activity. Sexual crossing of two M. heterothallica showed that progenies had a large genetic and physiological diversity. In the future, this will allow further improvement of the plant biomass-degrading enzyme mixtures of M. heterothallica. PMID:23241981

An Extensive Alien Plant Inventory from the Inhabited Areas of Galapagos

PubMed Central

Guézou, Anne; Trueman, Mandy; Buddenhagen, Christopher Evan; Chamorro, Susana; Guerrero, Ana Mireya; Pozo, Paola; Atkinson, Rachel

2010-01-01

Background Plant invasions are causing habitat degradation in Galapagos. Problems are concentrated on the four inhabited islands. Plants introduced to rural areas in the humid highlands and urban areas on the arid coast act as foci for invasion of the surrounding Galapagos National Park. Methodology/Principal Findings Here we present results of the most comprehensive inventory to date of alien vascular plants in the inhabited areas of Galapagos. The survey was conducted between 2002 and 2007, in 6031 properties (97% of the total) on Floreana, Isabela, San Cristobal and Santa Cruz Islands. In total 754 alien vascular plant taxa were recorded, representing 468 genera in 123 families. Dicotyledons represented 554 taxa, monocotyledons 183, there were 7 gymnosperms and 10 pteridophytes. Almost half (363) of the taxa were herbaceous. The most represented families were Fabaceae (sensu lato), Asteraceae and Poaceae. The three most recorded species in the humid rural areas were Psidium guajava, Passiflora edulis and Bryophyllum pinnatum, and in the dry urban areas, Aloe vera, Portulaca oleracea and Carica papaya. In total, 264 (35%) taxa were recorded as naturalized. The most common use for taxa was ornamental (52%). Conclusions/Significance This extensive survey has increased the known alien vascular flora of Galapagos by 257 species, giving a ratio of alien to native taxa of 1.57∶1. It provides a crucial baseline for plant invasion management in the archipelago and contributes data for meta analyses of invasion processes worldwide. A repeat of the survey in the future would act as an effective early detection tool to help avoid further invasion of the Galapagos National Park. PMID:20421999

Estimating vegetation vulnerability to detect areas prone to land degradation in the Mediterranean basin

NASA Astrophysics Data System (ADS)

Imbrenda, Vito; Coluzzi, Rosa; D'Emilio, Mariagrazia; Lanfredi, Maria; Simoniello, Tiziana

2013-04-01

Vegetation is one of the key components to study land degradation vulnerability because of the complex interactions and feedbacks that link it to soil. In the Mediterranean region, degradation phenomena are due to a mix of predisposing factors (thin soil horizons, low soil organic matter, increasing aridity, etc.) and bad management practices (overgrazing, deforestation, intensification of agriculture, tourism development). In particular, in areas threatened by degradation processes but still covered by vegetation, large scale soil condition evaluation is a hard task and the detection of stressed vegetation can be useful to identify on-going soil degradation phenomena and to reduce their impacts through interventions for recovery/rehabilitation. In this context the use of satellite time series can increase the efficacy and completeness of the land degradation assessment, providing precious information to understand vegetation dynamics. In order to estimate vulnerability levels in Basilicata (a Mediterranean region of Southern Italy) in the framework of PRO-LAND project (PO-FESR Basilicata 2007-2013), we crossed information on potential vegetation vulnerability with information on photosynthetic activity dynamics. Potential vegetation vulnerability represents the vulnerability related to the type of present cover in terms of fire risk, erosion protection, drought resistance and plant cover distribution. It was derived from an updated land cover map by separately analyzing each factor, and then by combining them to obtain concise information on the possible degradation exposure. The analysis of photosynthetic activity dynamics provides information on the status of vegetation, that is fundamental to discriminate the different vulnerability levels within the same land cover, i.e. the same potential vulnerability. For such a purpose, we analyzed a time series (2000-2010) of a satellite vegetation index (MODIS NDVI) with 250m resolution, available as 16-day composite

Traditional uses of plants in a rural community of Mozambique and possible links with Miombo degradation and harvesting sustainability.

PubMed

Bruschi, Piero; Mancini, Matteo; Mattioli, Elisabetta; Morganti, Michela; Signorini, Maria Adele

2014-07-23

Miombo woodlands play an important role in the livelihood of people living in sub-equatorial African countries, contributing to satisfy basic human needs such as food, medicine, fuelwood and building materials. However, over-exploitation of plant resources and unsustainable harvest practices can potentially degrade forests. The aim of this study was to document the use of Miombo plant products, other than medicinal plants, in local communities, within a wider framework in which we discussed possible links between traditional uses and conservation status of the used species and of the whole Miombo environment. Fieldwork took place in four communities of Muda-Serração, central Mozambique. We conducted semi-structured interviews with 52 informants about their knowledge, use and harvesting practices of useful plants. A survey on local Miombo vegetation was also carried out in order to assess abundance and distribution of useful woody plants cited in the interviews in areas exposed to different exploitation rates. A Conservation Priority index was also applied to rank conservation values of each used woody species. Ninety-eight plants cited by the informants were botanically identified. The most relevant general category was represented by food plants (45 species), followed by handicraft plants (38 species) and domestic plants (37 species). Among the 54 woody species observed in vegetation plots, 52% were cited as useful in the interviews. Twenty-six woody species found in 'natural' Miombo areas were not found in 'degraded' ones: of these, 46% were cited in the interviews (58% in the food category, 50% in the handicraft category, 25% in the domestic category and 8% in the fishing category). Results of conservation ranking showed that 7 woody species deserve conservation priority in the investigated area. This study shows that the communities investigated rely heavily on local forest products for their daily subsistence requirements in food, firewood/charcoal and

Arsenal of plant cell wall degrading enzymes reflects host preference among plant pathogenic fungi

USDA-ARS?s Scientific Manuscript database

Discovery and development of novel plant cell wall degrading enzymes is a key step towards more efficient depolymerization of polysaccharides to fermentable sugars for production of liquid transportation biofuels and other bioproducts. The industrial fungus Trichoderma reesei is known to be highly c...

Plant species influence on soil C after afforestation of Mediterranean degraded soils

NASA Astrophysics Data System (ADS)

Dominguez, Maria T.; García-Vargas, Carlos; Madejón, Engracia; Marañón, Teodoro

2015-04-01

Increasing C sequestration in terrestrial ecosystems is one of the main current environmental challenges to mitigate climate change. Afforestation of degraded and contaminated lands is one of the key strategies to achieve an increase in C sequestration in ecosystems. Plant species differ in their mechanisms of C-fixation, C allocation into different plant organs, and interaction with soil microorganisms, all these factors influencing the dynamics of soil C following the afforestation of degraded soils. In this work we examine the influence of different woody plant species on soil C dynamics in degraded and afforested Mediterranean soils. The soils were former agricultural lands that were polluted by a mining accident and later afforested with different native plant species. We analysed the effect of four of these species (Olea europaea var. sylvestris Brot., Populus alba L., Pistacia lentiscus L. and Retama sphaerocarpa (L.) Boiss.) on different soil C fractions, soil nutrient availability, microbial activity (soil enzyme activities) and soil CO2 fluxes 15 years after the establishment of the plantations. Results suggest that the influence of the planted trees and shrubs is still limited, being more pronounced in the more acidic and nutrient-poor soils. Litter accumulation varied among species, with the highest C accumulated in the litter under the deciduous species (Populus alba L.). No differences were observed in the amount of total soil organic C among the studied species, or in the concentrations of phenols and sugars in the dissolved organic C (DOC), which might have indicated differences in the biodegradability of the DOC. Microbial biomass and activity was highly influenced by soil pH, and plant species had a significant influence on soil pH in the more acidic site. Soil CO2 fluxes were more influenced by the plant species than total soil C content. Our results suggest that changes in total soil C stocks after the afforestation of degraded Mediterranean

Expression of CphB- and CphE-type cyanophycinases in cyanophycin-producing tobacco and comparison of their ability to degrade cyanophycin in plant and plant extracts.

PubMed

Ponndorf, Daniel; Broer, Inge; Nausch, Henrik

2017-08-01

Increasing the arginine (Arg) content in plants used as feed or food is of interest, since the supplementation of food with conditionally essential Arg has been shown to have nutritional benefits. An increase was achieved by the expression of the Arg-rich bacterial storage component, cyanophycin (CGP), in the chloroplast of transgenic plants. CGP is stable in plants and its degradation into β-aspartic acid (Asp)-Arg dipeptides, is solely catalyzed by bacterial cyanophycinases (CGPase). Dipeptides can be absorbed by animals even more efficiently than free amino acids (Matthews and Adibi 1976; Wenzel et al. 2001). The simultaneous production of CGP and CGPase in plants could be a source of β-Asp-Arg dipeptides if CGP degradation can be prevented in planta or if dipeptides are stable in the plants. We have shown for the first time that it is possible to co-express CGP and CGPase in the same plant without substrate degradation in planta by transient expression of the cyanobacterial CGPase CPHB (either in the plastid or cytosol), and the non-cyanobacterial CGPase CPHE (cytosol) in CGP-producing Nicotiana tabacum plants. We compared their ability to degrade CGP in planta and in crude plant extracts. No CGP degradation appeared prior to cell homogenization independent of the CGPase produced. In crude plant extracts, only cytosolic CPHE led to a fast degradation of CGP. CPHE also showed higher stability and in vitro activity compared to both CPHB variants. This work is the next step to increase Arg in forage plants using a stable, Arg-rich storage protein.

Restoration of areas degraded by alluvial sand mining: use of soil microbiological activity and plant biomass growth to assess evolution of restored riparian vegetation.

PubMed

Venson, Graziela R; Marenzi, Rosemeri C; Almeida, Tito César M; Deschamps-Schmidt, Alexandre; Testolin, Renan C; Rörig, Leonardo R; Radetski, Claudemir M

2017-03-01

River or alluvial sand mining is causing a variety of environmental problems in the Itajaí-açú river basin in Santa Catarina State (south of Brazil). When this type of commercial activity degrades areas around rivers, environmental restoration programs need to be executed. In this context, the aim of this study was to assess the evolution of a restored riparian forest based on data on the soil microbial activity and plant biomass growth. A reference site and three sites with soil degradation were studied over a 3-year period. Five campaigns were performed to determine the hydrolysis of the soil enzyme fluorescein diacetate (FDA), and the biomass productivity was determined at the end of the studied period. The variation in the enzyme activity for the different campaigns at each site was low, but this parameter did differ significantly according to the site. Well-managed sites showed the highest biomass productivity, and this, in turn, showed a strong positive correlation with soil enzyme activity. In conclusion, soil enzyme activity could form the basis for monitoring and the early prediction of the success of vegetal restoration programs, since responses at the higher level of biological organization take longer, inhibiting the assessment of the project within an acceptable time frame.

Solar plants, environmental degradation and local socioeconomic contexts: A case study in a Mediterranean country

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delfanti, Lavinia; Colantoni, Andrea, E-mail: colantoni@unitus.it; Recanatesi, Fabio

Photovoltaic plants developed on rural land are becoming a common infrastructure in the Mediterranean region and may contribute, at least indirectly, to various forms of environmental degradation including landscape deterioration, land take, soil degradation and loss in traditional cropland and biodiversity. Our study illustrates a procedure estimating (i) the extension of ground-mounted photovoltaic fields at the municipal scale in Italy and (ii) inferring the socioeconomic profile of the Italian municipalities experiencing different expansion rates of ground-mounted photovoltaic fields over the last years (2007-2014). The procedure was based on diachronic information derived from official data sources integrated into a geographical decisionmore » support system. Our results indicate that the surface area of ground-mounted photovoltaic fields into rural land grew continuously in Italy between 2007 and 2014 with positive and increasing growth rates observed during 2007-2011 and positive but slightly decreasing growth rates over 2012-2014, as a result of market saturation and policies containing the diffusion of solar plants on greenfields. We found important differences in the density of ground-mounted solar plants between northern and southern Italian municipalities. We identified accessible rural municipalities in southern Italy with intermediate population density and large availability of non-urban land as the most exposed to the diffusion of solar plants on greenfields in the last decade. Our approach is a promising tool to estimate changes in the use of land driven by the expansion of photovoltaic fields into rural land.« less

Model of succession in degraded areas based on carabid beetles (Coleoptera, Carabidae).

PubMed

Schwerk, Axel; Szyszko, Jan

2011-01-01

Degraded areas constitute challenging tasks with respect to sustainable management of natural resources. Maintaining or even establishing certain successional stages seems to be particularly important. This paper presents a model of the succession in five different types of degraded areas in Poland based on changes in the carabid fauna. Mean Individual Biomass of Carabidae (MIB) was used as a numerical measure for the stage of succession. The run of succession differed clearly among the different types of degraded areas. Initial conditions (origin of soil and origin of vegetation) and landscape related aspects seem to be important with respect to these differences. As characteristic phases, a 'delay phase', an 'increase phase' and a 'stagnation phase' were identified. In general, the runs of succession could be described by four different parameters: (1) 'Initial degradation level', (2) 'delay', (3) 'increase rate' and (4) 'recovery level'. Applying the analytic solution of the logistic equation, characteristic values for the parameters were identified for each of the five area types. The model is of practical use, because it provides a possibility to compare the values of the parameters elaborated in different areas, to give hints for intervention and to provide prognoses about future succession in the areas. Furthermore, it is possible to transfer the model to other indicators of succession.

Model of succession in degraded areas based on carabid beetles (Coleoptera, Carabidae)

PubMed Central

Schwerk, Axel; Szyszko, Jan

2011-01-01

Abstract Degraded areas constitute challenging tasks with respect to sustainable management of natural resources. Maintaining or even establishing certain successional stages seems to be particularly important. This paper presents a model of the succession in five different types of degraded areas in Poland based on changes in the carabid fauna. Mean Individual Biomass of Carabidae (MIB) was used as a numerical measure for the stage of succession. The run of succession differed clearly among the different types of degraded areas. Initial conditions (origin of soil and origin of vegetation) and landscape related aspects seem to be important with respect to these differences. As characteristic phases, a ‘delay phase’, an ‘increase phase’ and a ‘stagnation phase’ were identified. In general, the runs of succession could be described by four different parameters: (1) ‘Initial degradation level’, (2) ‘delay’, (3) ‘increase rate’ and (4) ‘recovery level’. Applying the analytic solution of the logistic equation, characteristic values for the parameters were identified for each of the five area types. The model is of practical use, because it provides a possibility to compare the values of the parameters elaborated in different areas, to give hints for intervention and to provide prognoses about future succession in the areas. Furthermore, it is possible to transfer the model to other indicators of succession. PMID:21738419

Comparative analysis of fungal genomes reveals different plant cell wall degrading capacity in fungi

PubMed Central

2013-01-01

Background Fungi produce a variety of carbohydrate activity enzymes (CAZymes) for the degradation of plant polysaccharide materials to facilitate infection and/or gain nutrition. Identifying and comparing CAZymes from fungi with different nutritional modes or infection mechanisms may provide information for better understanding of their life styles and infection models. To date, over hundreds of fungal genomes are publicly available. However, a systematic comparative analysis of fungal CAZymes across the entire fungal kingdom has not been reported. Results In this study, we systemically identified glycoside hydrolases (GHs), polysaccharide lyases (PLs), carbohydrate esterases (CEs), and glycosyltransferases (GTs) as well as carbohydrate-binding modules (CBMs) in the predicted proteomes of 103 representative fungi from Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota. Comparative analysis of these CAZymes that play major roles in plant polysaccharide degradation revealed that fungi exhibit tremendous diversity in the number and variety of CAZymes. Among them, some families of GHs and CEs are the most prevalent CAZymes that are distributed in all of the fungi analyzed. Importantly, cellulases of some GH families are present in fungi that are not known to have cellulose-degrading ability. In addition, our results also showed that in general, plant pathogenic fungi have the highest number of CAZymes. Biotrophic fungi tend to have fewer CAZymes than necrotrophic and hemibiotrophic fungi. Pathogens of dicots often contain more pectinases than fungi infecting monocots. Interestingly, besides yeasts, many saprophytic fungi that are highly active in degrading plant biomass contain fewer CAZymes than plant pathogenic fungi. Furthermore, analysis of the gene expression profile of the wheat scab fungus Fusarium graminearum revealed that most of the CAZyme genes related to cell wall degradation were up-regulated during plant infection. Phylogenetic analysis also

Degradation of PVC/HC blends. II. Terrestrial plant growth test.

PubMed

Pascu, Mihaela; Agafiţei, Gabriela-Elena; Profire, Lenuţa; Vasile, Cornelia

2009-01-01

The behavior at degradation by soil burial of some plasticized polyvinyl chloride (PVC) based blends with a variable content of hydrolyzed collagen (HC) has been followed. The modifications induced in the environment by the polymer systems (pH variation, physiologic state of the plants, assimilatory pigments) were studied. Using the growth test of the terrestrial plants, we followed the development of Triticum (wheat), Helianthus annus minimus (little sunflower), Pisum sativum (pea), and Vicia X hybrida hort, during a vegetation cycle. After the harvest, for each plant, the quantities of chlorophyll and carotenoidic pigments and of trace- and macroelements were determined. It was proved that, in the presence of polymer blends, the plants do not suffer morphological and physiological modifications, the products released in the culture soil being not toxic for the plants growth.

Metagenomic Characterization and Biochemical Analysis of Cellulose-Degrading Bacterial Communities from Sheep Rumen, Termite Hindgut, Decaying Plant Materials, and Soil

DTIC Science & Technology

2016-01-04

Biochemical Analysis of Cellulose-DegradingBacterial Communities from Sheep Rumen, Termite Hindgut, Decaying Plant Materials,and Soil In an effort to...degrading bacteria from various samples, including termite gut, sheep rumen, soil, and decaying plant materials. Using selective media culture with...Metagenomic Characterization and Biochemical Analysis of Cellulose-DegradingBacterial Communities from Sheep Rumen, Termite Hindgut, Decaying Plant

Calcium content and high calcium adaptation of plants in karst areas of southwestern Hunan, China

NASA Astrophysics Data System (ADS)

Wei, Xiaocong; Deng, Xiangwen; Xiang, Wenhua; Lei, Pifeng; Ouyang, Shuai; Wen, Hongfang; Chen, Liang

2018-05-01

Rocky desertification is a major ecological problem of land degradation in karst areas. In these areas, the high soil calcium (Ca) content has become an important environmental factor that can affect the restoration of vegetation. Consequently, the screening of plant species that can adapt to high Ca soil environments is a critical step in vegetation restoration. In this study, three grades of rocky desertification sample areas were selected in karst areas of southwestern Hunan, China (LRD: light rocky desertification; MRD: moderate rocky desertification; and IRD: intense rocky desertification). Each grade of these sample areas had three sample plots in different slope positions, each of which had four small quadrats (one in rocky-side areas, three in non-rocky-side areas). We measured the Ca content of leaves, branches, and roots from 41 plant species, as well as soil total Ca (TCa) and exchangeable Ca (ECa) at depths of 0-15, 15-30, and 30-45 cm in each small quadrat. The results showed that the soil Ca2+ content in rocky-side areas was significantly higher than that in non-rocky-side areas (p < 0.05). The mean soil TCa and ECa content increased gradually along with the grade of rocky desertification, in the order IRD > MRD > LRD. For all plant functional groups, the plant Ca content of aboveground parts was significantly higher than that of the belowground parts (p < 0.05). The soil ECa content had significant effects on plant Ca content of the belowground parts but had no significant effects on plant Ca content of the aboveground parts. Of the 41 plant species that were sampled, 17 were found to be dominant (important value > 1). The differences in Ca2+ content between the aboveground and belowground parts of the 17 dominant species were calculated, and their correlations with soil ECa content were analyzed. The results showed that these 17 species can be divided into three categories: Ca-indifferent plants, high-Ca plants, and low-Ca plants. These findings

Virulence of plant pathogenic bacteria attenuated by degradation of fatty acid cell-to-cell signaling factors.

PubMed

Newman, Karyn L; Chatterjee, Subhadeep; Ho, Kimberly A; Lindow, Steven E

2008-03-01

Diffusible signal factor (DSF) is a fatty acid signal molecule involved in regulation of virulence in several Xanthomonas species as well as Xylella fastidiosa. In this study, we identified a variety of bacteria that could disrupt DSF-mediated induction of virulence factors in Xanthomonas campestris pv. campestris. While many bacteria had the ability to degrade DSF, several bacterial strains belonging to genera Bacillus, Paenibacillus, Microbacterium, Staphylococcus, and Pseudomonas were identified that were capable of particularly rapid degradation of DSF. The molecular determinants for rapid degradation of DSF in Pseudomonas spp. strain G were elucidated. Random transposon mutants of strain G lacking the ability to degrade DSF were isolated. Cloning and characterization of disrupted genes in these strains revealed that carAB, required for the synthesis of carbamoylphosphate, a precursor for pyrimidine and arginine biosynthesis is required for rapid degradation of DSF in strain G. Complementation of carAB mutants restored both pyrimidine prototrophy and DSF degradation ability of the strain G mutant. An Escherichia coli strain harboring carAB of Pseudomonas spp. strain G degrades DSF more rapidly than the parental strain, and overexpression of carAB in trans increased the ability of Pseudomonas spp. strain G to degrade as compared with the parental strain. Coinoculation of X. campestris pv. campestris with DSF-degrading bacteria into mustard and cabbage leaves reduced disease severity up to twofold compared with plants inoculated only with the pathogen. Likewise, disease incidence and severity in grape stems coinoculated with Xylella fastidiosa and DSF-degrading strains were significantly reduced compared with plants inoculated with the pathogen alone. Coinoculation of grape plants with a carAB mutant of Pseudomonas spp. strain G complemented with carAB in trans reduced disease severity as well or better than the parental strain. These results indicate that

Micropore surface area of alkali-soluble plant macromolecules (humic acids) drives their decomposition rates in soil.

PubMed

Papa, Gabriella; Spagnol, Manuela; Tambone, Fulvia; Pilu, Roberto; Scaglia, Barbara; Adani, Fabrizio

2010-02-01

Previous studies suggested that micropore surface area (MSA) of alkali-soluble bio-macromolecules of aerial plant residues of maize constitutes an important factor that explains their humification in soil, that is, preservation against biological degradation. On the other hand, root plant residue contributes to the soil humus balance, as well. Following the experimental design used in a previous paper published in this journal, this study shows that the biochemical recalcitrance of the alkali-soluble acid-insoluble fraction of the root plant material, contributed to the root maize humification of both Wild-type maize plants and its corresponding mutant brown midrib (bm3), this latter characterized by reduced lignin content. Humic acids (HAs) existed in root (root-HAs) were less degraded in soil than corresponding HAs existed in shoot (shoot-HAs): shoot-HAs bm3 (48%)>shoot-HAs Wild-type (37%)>root-HAs Wild-type (33%)>root-HAs bm3 (22%) (degradability shown in parenthesis). These differences were related to the MSA of HAs, that is, root-HAs having a higher MSA than shoot-HAs: shoot-HAs bm3 (41.43+/-1.2m(2)g(-1))degradability of HAs and HA-MSAs (r=-0.88, P<0.08, n=4), confirming that MSA was able to explain bio-macromolecules recalcitrance in soil.

Ralstonia solanacearum Type III Effector RipAY Is a Glutathione-Degrading Enzyme That Is Activated by Plant Cytosolic Thioredoxins and Suppresses Plant Immunity.

PubMed

Mukaihara, Takafumi; Hatanaka, Tadashi; Nakano, Masahito; Oda, Kenji

2016-04-12

The plant pathogen Ralstonia solanacearum uses a large repertoire of type III effector proteins to succeed in infection. To clarify the function of effector proteins in host eukaryote cells, we expressed effectors in yeast cells and identified seven effector proteins that interfere with yeast growth. One of the effector proteins, RipAY, was found to share homology with the ChaC family proteins that function as γ-glutamyl cyclotransferases, which degrade glutathione (GSH), a tripeptide that plays important roles in the plant immune system. RipAY significantly inhibited yeast growth and simultaneously induced rapid GSH depletion when expressed in yeast cells. The in vitro GSH degradation activity of RipAY is specifically activated by eukaryotic factors in the yeast and plant extracts. Biochemical purification of the yeast protein identified that RipAY is activated by thioredoxin TRX2. On the other hand, RipAY was not activated by bacterial thioredoxins. Interestingly, RipAY was activated by plant h-type thioredoxins that exist in large amounts in the plant cytosol, but not by chloroplastic m-, f-, x-, y- and z-type thioredoxins, in a thiol-independent manner. The transient expression of RipAY decreased the GSH level in plant cells and affected the flg22-triggered production of reactive oxygen species (ROS) and expression of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) marker genes in Nicotiana benthamiana leaves. These results indicate that RipAY is activated by host cytosolic thioredoxins and degrades GSH specifically in plant cells to suppress plant immunity. Ralstonia solanacearum is the causal agent of bacterial wilt disease of plants. This pathogen injects virulence effector proteins into host cells to suppress disease resistance responses of plants. In this article, we report a biochemical activity of R. solanacearum effector protein RipAY. RipAY can degrade GSH, a tripeptide that plays important roles in the plant immune system, with

Exotic plant species attack revegetation plants in post-coal mining areas

NASA Astrophysics Data System (ADS)

Yusuf, Muhammad; Arisoesilaningsih, Endang

2017-11-01

This study aimed to explore some invasive exotic plant species that have the potential to disrupt the growth of revegetation plants in post-coal mining areas. This research was conducted in a revegetation area of PT, Amanah Anugerah Adi Mulia (A3M) Kintap site, South Borneo. Direct observation was carried out on some revegetation areas by observing the growth of revegetation plants disturbed by exotic plant species and the spread of exotic plant species. Based on observation, several invasive exotic plant species were identified including Mikania cordata, Centrosema pubescence, Calopogonium mucunoides, Mimosa pudica, Ageratum conyzoides, and Chromolaena odorata. These five plant species grew wild in the revegetation area and showed ability to disrupt the growth of other plants. In some tree species, such as Acacia mangium, Paraserianthes falcataria, M. cordata could inhibit the growth and even kill the trees through covering the tree canopy. So, the trees could not receive optimum sun light for photosynthesis processes. M. cordata was also observed to have the most widespread distribution. Several exotic plant species such as C. mucunoides, M. pudica, and A. conyzoides were observed to have deep root systems compared with plant species used for revegetation. This growth characteristic allowed exotic plant species to win the competition for nutrient absorption with other plant species.

Petroleum degradation by endophytic Streptomyces spp. isolated from plants grown in contaminated soil of southern Algeria.

PubMed

Baoune, Hafida; Ould El Hadj-Khelil, Aminata; Pucci, Graciela; Sineli, Pedro; Loucif, Lotfi; Polti, Marta Alejandra

2018-01-01

Petroleum hydrocarbons are well known by their high toxicity and recalcitrant properties. Their increasing utilization around worldwide led to environmental contamination. Phytoremediation using plant-associated microbe is an interesting approach for petroleum degradation and actinobacteria have a great potential for that. For this purpose, our study aimed to isolate, characterize, and assess the ability of endophytic actinobacteria to degrade crude petroleum, as well as to produce plant growth promoting traits. Seventeen endophytic actinobacteria were isolated from roots of plants grown naturally in sandy contaminated soil. Among them, six isolates were selected on the basis of their tolerance to petroleum on solid minimal medium and characterized by 16S rDNA gene sequencing. All petroleum-tolerant isolates belonged to the Streptomyces genus. Determination by crude oil degradation by gas chromatorgraph-flame ionization detector revealed that five strains could use petroleum as sole carbon and energy source and the petroleum removal achieved up to 98% after 7 days of incubation. These isolates displayed an important role in the degradation of the n-alkanes (C 6 -C 30 ), aromatic and polycyclic aromatic hydrocarbons. All strains showed a wide range of plant growth promoting features such as siderophores, phosphate solubilization, 1-aminocyclopropane-1-carboxylate deaminase, nitrogen fixation and indole-3-acetic acid production as well as biosurfactant production. This is the first study highlighting the petroleum degradation ability and plant growth promoting attributes of endophytic Streptomyces. The finding suggests that the endophytic actinobacteria isolated are promising candidates for improving phytoremediation efficiency of petroleum contaminated soil. Copyright © 2017 Elsevier Inc. All rights reserved.

E-Area Vault Concrete Material Property And Vault Durability/Degradation Projection Recommendations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phifer, M. A.

2014-03-11

Subsequent to the 2008 E-Area Low-Level Waste Facility (ELLWF) Performance Assessment (PA) (WSRC 2008), two additional E-Area vault concrete property testing programs have been conducted (Dixon and Phifer 2010 and SIMCO 2011a) and two additional E-Area vault concrete durability modeling projections have been made (Langton 2009 and SIMCO 2012). All the information/data from these reports has been evaluated and consolidated herein by the Savannah River National Laboratory (SRNL) at the request of Solid Waste Management (SWM) to produce E-Area vault concrete hydraulic and physical property data and vault durability/degradation projection recommendations that are adequately justified for use within associated Specialmore » Analyses (SAs) and future PA updates. The Low Activity Waste (LAW) and Intermediate Level (IL) Vaults structural degradation predictions produced by Carey 2006 and Peregoy 2006, respectively, which were used as the basis for the 2008 ELLWF PA, remain valid based upon the results of the E-Area vault concrete durability simulations reported by Langton 2009 and those reported by SIMCO 2012. Therefore revised structural degradation predictions are not required so long as the mean thickness of the closure cap overlying the vaults is no greater than that assumed within Carey 2006 and Peregoy 2006. For the LAW Vault structural degradation prediction (Carey 2006), the mean thickness of the overlying closure cap was taken as nine feet. For the IL Vault structural degradation prediction (Peregoy 2006), the mean thickness of the overlying closure cap was taken as eight feet. The mean closure cap thicknesses as described here for both E-Area Vaults will be included as a key input and assumption (I&A) in the next revision to the closure plan for the ELLWF (Phifer et al. 2009). In addition, it has been identified as new input to the PA model to be assessed in the ongoing update to the new PA Information UDQE (Flach 2013). Once the UDQE is approved, the SWM Key I

Recognition and Degradation of Plant Cell Wall Polysaccharides by Two Human Gut Symbionts

PubMed Central

Chiang, Herbert; Pudlo, Nicholas A.; Wu, Meng; McNulty, Nathan P.; Abbott, D. Wade; Henrissat, Bernard; Gilbert, Harry J.; Bolam, David N.; Gordon, Jeffrey I.

2011-01-01

Symbiotic bacteria inhabiting the human gut have evolved under intense pressure to utilize complex carbohydrates, primarily plant cell wall glycans in our diets. These polysaccharides are not digested by human enzymes, but are processed to absorbable short chain fatty acids by gut bacteria. The Bacteroidetes, one of two dominant bacterial phyla in the adult gut, possess broad glycan-degrading abilities. These species use a series of membrane protein complexes, termed Sus-like systems, for catabolism of many complex carbohydrates. However, the role of these systems in degrading the chemically diverse repertoire of plant cell wall glycans remains unknown. Here we show that two closely related human gut Bacteroides, B. thetaiotaomicron and B. ovatus, are capable of utilizing nearly all of the major plant and host glycans, including rhamnogalacturonan II, a highly complex polymer thought to be recalcitrant to microbial degradation. Transcriptional profiling and gene inactivation experiments revealed the identity and specificity of the polysaccharide utilization loci (PULs) that encode individual Sus-like systems that target various plant polysaccharides. Comparative genomic analysis indicated that B. ovatus possesses several unique PULs that enable degradation of hemicellulosic polysaccharides, a phenotype absent from B. thetaiotaomicron. In contrast, the B. thetaiotaomicron genome has been shaped by increased numbers of PULs involved in metabolism of host mucin O-glycans, a phenotype that is undetectable in B. ovatus. Binding studies of the purified sensor domains of PUL-associated hybrid two-component systems in conjunction with transcriptional analyses demonstrate that complex oligosaccharides provide the regulatory cues that induce PUL activation and that each PUL is highly specific for a defined cell wall polymer. These results provide a view of how these species have diverged into different carbohydrate niches by evolving genes that target unique suites of

ESCRT-dependent degradation of ubiquitylated plasma membrane proteins in plants.

PubMed

Isono, Erika; Kalinowska, Kamila

2017-12-01

To control the abundance of plasma membrane receptors and transporters is crucial for proper perception and response to extracellular signals from surrounding cells and the environment. Posttranslational modification of plasma membrane proteins, especially ubiquitin conjugation or ubiquitylation, is key for the determination of stability for many transmembrane proteins localized on the cell surface. The targeted degradation is ensured by a complex network of proteins among which the endosomal sorting complex required for transport (ESCRT) plays a central role. This review focuses on progresses made in recent years on the understanding of the function of the ESCRT machinery in the degradation of ubiquitylated plasma membrane proteins in plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Endosulfan Degradation by Selected Strains of Plant Growth Promoting Rhizobacteria.

PubMed

Rani, Rupa; Kumar, Vipin

2017-07-01

Sixty endosulfan tolerant bacterial strains were isolated from pesticide stressed agricultural soils. Five most tolerant strains were tested for plant growth promoting (PGP) activities and endosulfan degradation under different optimizing conditions in broth and soil. The strains PRB101 and PRB77 were the most efficient in terms of endosulfan degradation and PGP activities and showed solubilization indexes of 3.3 and 3.1 mm, indole acetic acid production of 71 and 68 μg mL -1 , siderophore zones of 13 mm each at the recommended dosage, respectively. Hydrogen cyanide and ammonia production remained unaffected in the presence of endosulfan. PRB101 and PRB77 strains were able to degrade 74% and 70% of endosulfan in broth and 67% and 63% in soil, respectively. Based on 16S rDNA analysis, the strains PRB101 and PRB77 exhibited 99% homology with Bacillus sp. KF984414 and Bacillus sp. LN849696, respectively.

Regulation of plant cell wall degradation by light in Trichoderma.

PubMed

Schmoll, Monika

2018-01-01

Trichoderma reesei (syn. Hypocrea jecorina ) is the model organism for industrial production of plant cell wall degradating enzymes. The integration of light and nutrient signals for adaptation of enzyme production in T. reesei emerged as an important regulatory mechanism to be tackled for strain improvement. Gene regulation specific for cellulase inducing conditions is different in light and darkness with substantial regulation by photoreceptors. Genes regulated by light are clustered in the genome, with several of the clusters overlapping with CAZyme clusters. Major cellulase transcription factor genes and at least 75% of glycoside hydrolase encoding genes show the potential of light dependent regulation. Accordingly, light dependent protein complex formation occurs within the promoters of cellulases and their regulators. Additionally growth on diverse carbon sources is different between light and darkness and dependent on the presence of photoreceptors in several cases. Thereby, also light intensity plays a regulatory role, with cellulase levels dropping at higher light intensities dependent in the strain background. The heterotrimeric G-protein pathway is the most important nutrient signaling pathway in the connection with light response and triggers posttranscriptional regulation of cellulase expression. All G-protein alpha subunits impact cellulase regulation in a light dependent manner. The downstream cAMP pathway is involved in light dependent regulation as well. Connections between the regulatory pathways are mainly established via the photoreceptor ENV1. The effect of photoreceptors on plant cell wall degradation also occurs in the model filamentous fungus Neurospora crassa . In the currently proposed model, T. reesei senses the presence of plant biomass in its environment by detection of building blocks of cellulose and hemicellulose. Interpretation of the respective signals is subsequently adjusted to the requirements in light and darkness (or on the

Plant-Associated Bacterial Degradation of Toxic Organic Compounds in Soil

PubMed Central

McGuinness, Martina; Dowling, David

2009-01-01

A number of toxic synthetic organic compounds can contaminate environmental soil through either local (e.g., industrial) or diffuse (e.g., agricultural) contamination. Increased levels of these toxic organic compounds in the environment have been associated with human health risks including cancer. Plant-associated bacteria, such as endophytic bacteria (non-pathogenic bacteria that occur naturally in plants) and rhizospheric bacteria (bacteria that live on and near the roots of plants), have been shown to contribute to biodegradation of toxic organic compounds in contaminated soil and could have potential for improving phytoremediation. Endophytic and rhizospheric bacterial degradation of toxic organic compounds (either naturally occurring or genetically enhanced) in contaminated soil in the environment could have positive implications for human health worldwide and is the subject of this review. PMID:19742157

Catabolism of volatile organic compounds influences plant survival.

PubMed

Oikawa, Patricia Y; Lerdau, Manuel T

2013-12-01

Plants emit a diverse array of phytogenic volatile organic compounds (VOCs). The production and emission of VOCs has been an important area of research for decades. However, recent research has revealed the importance of VOC catabolism by plants and VOC degradation in the atmosphere for plant growth and survival. Specifically, VOC catabolism and degradation have implications for plant C balance, tolerance to environmental stress, plant signaling, and plant-atmosphere interactions. Here we review recent advances in our understanding of VOC catabolism and degradation, propose experiments for investigating VOC catabolism, and suggest ways to incorporate catabolism into VOC emission models. Improving our knowledge of VOC catabolism and degradation is crucial for understanding plant metabolism and predicting plant survival in polluted environments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

PubMed Central

Aylward, Frank O.; Burnum-Johnson, Kristin E.; Tringe, Susannah G.; Teiling, Clotilde; Tremmel, Daniel M.; Moeller, Joseph A.; Scott, Jarrod J.; Barry, Kerrie W.; Piehowski, Paul D.; Nicora, Carrie D.; Malfatti, Stephanie A.; Monroe, Matthew E.; Purvine, Samuel O.; Goodwin, Lynne A.; Smith, Richard D.; Weinstock, George M.; Gerardo, Nicole M.; Suen, Garret; Lipton, Mary S.

2013-01-01

Plants represent a large reservoir of organic carbon comprised primarily of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous fungus that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass is degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and, using genomic and metaproteomic tools, we investigate its role in lignocellulose degradation in the gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in ant gardens and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that likely play an important role in lignocellulose degradation. Our study provides a detailed analysis of plant biomass degradation in leaf-cutter ant fungus gardens and insight into the enzymes underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar. PMID:23584789

Can salt marsh plants influence levels and distribution of DDTs in estuarine areas?

NASA Astrophysics Data System (ADS)

Carvalho, Pedro N.; Rodrigues, Pedro Nuno R.; Evangelista, Rafael; Basto, M. Clara P.; Vasconcelos, M. Teresa S. D.

2011-07-01

Sediments are depositories of toxic substances such as organochlorine pesticides and there is a global need for their removal in contaminated environments. Studies that combine contaminated sediments and phytoremediation are relatively recent and their number has been increasing. This work aimed to investigate whether salt marsh plants (sea club-rush Scirpus maritimus, sea rush Juncus maritimus and sea purslane Halimione portulacoides) can favor DDT and metabolites remediation in estuarine environment. For this purpose the levels of DDT, DDE and DDD were compared in vegetated and non-vegetated sediments from an estuary in the North of Portugal ( in-situ study) and from another in the South of Portugal ( ex-situ study). Results obtained both in the in-situ study, involving S. maritimus and J. maritimus, and in the ex-situ study, involving H. portulacoides, indicated that these plants did not have a significant role in DDTs removal and/or degradation. Therefore, it seems that the tested plants cannot influence levels and distribution of DDTs in estuarine areas.

Hydroxycinnamic acid degradation, a broadly conserved trait, protects Ralstonia solanacearum from chemical plant defenses and contributes to root colonization and virulence

PubMed Central

Lowe, Tiffany M.; Ailloud, Florent; Allen, Caitilyn

2014-01-01

Plants produce hydroxycinnamic acid defense compounds (HCAs) to combat pathogens, such as the bacterium Ralstonia solanacearum. We showed that an HCA degradation pathway is genetically and functionally conserved across diverse R. solanacearum strains. Further, a Δfcs (feruloyl-CoA synthetase) mutant that cannot degrade HCAs was less virulent on tomato plants. To understand the role of HCA degradation in bacterial wilt disease, we tested the following hypotheses: HCA degradation helps the pathogen (1) grow, as a carbon source; (2) spread, by reducing physical barriers HCA-derived; and (3) survive plant antimicrobial compounds. Although HCA degradation enabled R. solanacearum growth on HCAs in vitro, HCA degradation was dispensable for growth in xylem sap and root exudate, suggesting that HCAs are not significant carbon sources in planta. Acetyl-bromide quantification of lignin demonstrated that R. solanacearum infections did not affect the gross quantity or distribution of stem lignin. However, the Δfcs mutant was significantly more susceptible to inhibition by two HCAs: caffeate and p-coumarate. Finally, plant colonization assays suggested that HCA degradation facilitates early stages of infection and root colonization. Together, these results indicated that ability to degrade HCAs contributes to bacterial wilt virulence by facilitating root entry and by protecting the pathogen from HCA toxicity. PMID:25423265

Polysaccharide Degradation

NASA Astrophysics Data System (ADS)

Stone, Bruce A.; Svensson, Birte; Collins, Michelle E.; Rastall, Robert A.

An overview of current and potential enzymes used to degrade polysaccharides is presented. Such depolymerases are comprised of glycoside hydrolases, glycosyl transferases, phosphorylases and lyases, and their classification, active sites and action patterns are discussed. Additionally, the mechanisms that these enzymes use to cleave glycosidic linkages is reviewed as are inhibitors of depolymerase activity; reagents which react with amino acid residues, glycoside derivatives, transition state inhibitors and proteinaceous inhibitors. The characterization of various enzymes of microbial, animal or plant origin has led to their widespread use in the production of important oligosaccharides which can be incorporated into food stuffs. Sources of polysaccharides of particular interest in this chapter are those from plants and include inulin, dextran, xylan and pectin, as their hydrolysis products are purported to be functional foods in the context of gastrointestinal health. An alternative use of degraded polysaccharides is in the treatment of disease. The possibility exists to treat bacterial exopolysaccharide with lyases from bacteriophage to produce oligosaccharides exhibiting bioactive sequences. Although this area is currently in its infancy the knowledge is available to investigate further.

Hydrocarbon degradation potential and plant growth-promoting activity of culturable endophytic bacteria of Lotus corniculatus and Oenothera biennis from a long-term polluted site.

PubMed

Pawlik, Małgorzata; Cania, Barbara; Thijs, Sofie; Vangronsveld, Jaco; Piotrowska-Seget, Zofia

2017-08-01

Many endophytic bacteria exert beneficial effects on their host, but still little is known about the bacteria associated with plants growing in areas heavily polluted by hydrocarbons. The aim of the study was characterization of culturable hydrocarbon-degrading endophytic bacteria associated with Lotus corniculatus L. and Oenothera biennis L. collected in long-term petroleum hydrocarbon-polluted site using culture-dependent and molecular approaches. A total of 26 hydrocarbon-degrading endophytes from these plants were isolated. Phylogenetic analyses classified the isolates into the phyla Proteobacteria and Actinobacteria. The majority of strains belonged to the genera Rhizobium, Pseudomonas, Stenotrophomonas, and Rhodococcus. More than 90% of the isolates could grow on medium with diesel oil, approximately 20% could use n-hexadecane as a sole carbon and energy source. PCR analysis revealed that 40% of the isolates possessed the P450 gene encoding for cytochrome P450-type alkane hydroxylase (CYP153). In in vitro tests, all endophytic strains demonstrated a wide range of plant growth-promoting traits such as production of indole-3-acetic acid, hydrogen cyanide, siderophores, and phosphate solubilization. More than 40% of the bacteria carried the gene encoding for the 1-aminocyclopropane-1-carboxylic acid deaminase (acdS). Our study shows that the diversity of endophytic bacterial communities in tested plants was different. The results revealed also that the investigated plants were colonized by endophytic bacteria possessing plant growth-promoting features and a clear potential to degrade hydrocarbons. The properties of isolated endophytes indicate that they have the high potential to improve phytoremediation of petroleum hydrocarbon-polluted soils.

Multilocus sequence analysis reveals taxonomic differences among Bradyrhizobium sp. symbionts of Lupinus albescens plants growing in arenized and non-arenized areas.

PubMed

Granada, Camille E; Beneduzi, Anelise; Lisboa, Bruno B; Turchetto-Zolet, Andreia C; Vargas, Luciano K; Passaglia, Luciane M P

2015-07-01

Lupinus albescens is a leguminous plant that belongs to "New World" lupine species, which is native to southern Brazil. This Brazilian region is characterized by poor degraded soils with low organic matter and is designated as an arenized area. The symbiosis between Lupinus plants and nitrogen-fixing bacteria belonging to the Bradyrhizobium genus may help the plant establish itself in these areas. To characterize the bradyrhizobial population symbionts of L. albescens plants grown in arenized and non-arenized areas, a multilocus phylogenetic analysis allied to genetic diversity indices were conducted. Seventy-four bradyrhizobial isolates were analyzed, 38 coming from L. albescens plants growing in an arenized area and 36 from a non-arenized area. Isolates were different between arenized and non-arenized areas. Phylogenetic analysis of the 16S rRNA, dnaK, atpD, recA, glnII, rpoB, gyrB, nodA, nodB, and nodZ genes resulted in three supported clades, which were most likely to be three different new Bradyrhizobium species: one species from the arenized area and two from the non-arenized area. Estimates of genetic diversity, which decreased in arenized areas, were positively correlated with habitat variability. These results suggested that a few resistant and efficient Bradyrhizobium sp. strains were capable of forming nodules on L. albescens plants growing in an arenized area. An in vivo inoculation experiment with L. albescens plants showed that Bradyrhizobium ssp. isolated from this extreme environment were more efficient at promoting plant growth than those from the non-arenized area. This result suggested that the environment affected the selection of more efficient plant growth promoters in order to sustain plant growth. Copyright © 2015 Elsevier GmbH. All rights reserved.

Plant secondary metabolite-induced shifts in bacterial community structure and degradative ability in contaminated soil.

PubMed

Uhlik, Ondrej; Musilova, Lucie; Ridl, Jakub; Hroudova, Miluse; Vlcek, Cestmir; Koubek, Jiri; Holeckova, Marcela; Mackova, Martina; Macek, Tomas

2013-10-01

The aim of the study was to investigate how selected natural compounds (naringin, caffeic acid, and limonene) induce shifts in both bacterial community structure and degradative activity in long-term polychlorinated biphenyl (PCB)-contaminated soil and how these changes correlate with changes in chlorobiphenyl degradation capacity. In order to address this issue, we have integrated analytical methods of determining PCB degradation with pyrosequencing of 16S rRNA gene tag-encoded amplicons and DNA-stable isotope probing (SIP). Our model system was set in laboratory microcosms with PCB-contaminated soil, which was enriched for 8 weeks with the suspensions of flavonoid naringin, terpene limonene, and phenolic caffeic acid. Our results show that application of selected plant secondary metabolites resulted in bacterial community structure far different from the control one (no natural compound amendment). The community in soil treated with caffeic acid is almost solely represented by Proteobacteria, Acidobacteria, and Verrucomicrobia (together over 99 %). Treatment with naringin resulted in an enrichment of Firmicutes to the exclusion of Acidobacteria and Verrucomicrobia. SIP was applied in order to identify populations actively participating in 4-chlorobiphenyl catabolism. We observed that naringin and limonene in soil foster mainly populations of Hydrogenophaga spp., caffeic acid Burkholderia spp. and Pseudoxanthomonas spp. None of these populations were detected among 4-chlorobiphenyl utilizers in non-amended soil. Similarly, the degradation of individual PCB congeners was influenced by the addition of different plant compounds. Residual content of PCBs was lowest after treating the soil with naringin. Addition of caffeic acid resulted in comparable decrease of total PCBs with non-amended soil; however, higher substituted congeners were more degraded after caffeic acid treatment compared to all other treatments. Finally, it appears that plant secondary metabolites

Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots

NASA Astrophysics Data System (ADS)

Powell, C. L.; Goltz, M. N.; Agrawal, A.

2014-12-01

Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~ 1.9 mg L- 1, and initial aqueous [CAH] ~ 150 μg L- 1; cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12 ± 0.01 and 0.59 ± 0.07 d- 1, respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds.

Protected-Area Boundaries as Filters of Plant Invasions

PubMed Central

Foxcroft, Llewellyn C; JaroŠÍK, Vojtěch; Pyšek, Petr; Richardson, David M; Rouget, Mathieu

2011-01-01

Abstract Human land uses surrounding protected areas provide propagules for colonization of these areas by non-native species, and corridors between protected-area networks and drainage systems of rivers provide pathways for long-distance dispersal of non-native species. Nevertheless, the influence of protected-area boundaries on colonization of protected areas by invasive non-native species is unknown. We drew on a spatially explicit data set of more than 27,000 non-native plant presence records for South Africa's Kruger National Park to examine the role of boundaries in preventing colonization of protected areas by non-native species. The number of records of non-native invasive plants declined rapidly beyond 1500 m inside the park; thus, we believe that the park boundary limited the spread of non-native plants. The number of non-native invasive plants inside the park was a function of the amount of water runoff, density of major roads, and the presence of natural vegetation outside the park. Of the types of human-induced disturbance, only the density of major roads outside the protected area significantly increased the number of non-native plant records. Our findings suggest that the probability of incursion of invasive plants into protected areas can be quantified reliably. PMID:21166715

Leucoagaricus gongylophorus Produces Diverse Enzymes for the Degradation of Recalcitrant Plant Polymers in Leaf-Cutter Ant Fungus Gardens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aylward, Frank O.; Burnum-Johnson, Kristin E.; Tringe, Susannah G.

Plants represent a large reservoir of organic carbon comprised largely of recalcitrant polymers that most metazoans are unable to deconstruct. Many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. These ants use fresh foliar biomass as manure to cultivate fungus gardens composed primarily of Leucoagaricus gongylophorus, a basidiomycetous symbiont that produces specialized hyphal swellings that serve as a food source for the host ant colony. Although leaf-cutter ants are conspicuous herbivores that contribute substantially to carbon turnover in Neotropical ecosystems, the process through which plant biomass ismore » degraded in their fungus gardens is not well understood. Here we present the first draft genome of L. gongylophorus, and using genomic, metaproteomic, and phylogenetic tools we investigate its role in lignocellulose degradation in the fungus gardens of both Atta cephalotes and Acromyrmex echinatior leaf-cutter ants. We show that L. gongylophorus produces a diversity of lignocellulases in fungus gardens, and is likely the primary driver of plant biomass degradation in these ecosystems. We also show that this fungus produces distinct sets of lignocellulases throughout the different stages of biomass degradation, including numerous cellulases and laccases that may be playing an important but previously uncharacterized role in lignocellulose degradation. Our study provides a comprehensive analysis of plant biomass degradation in leaf-cutter ant fungus gardens and provides insight into the molecular dynamics underlying the symbiosis between these dominant herbivores and their obligate fungal cultivar.« less

Microbial degradation of plant leachate alters lignin phenols and trihalomethane precursors

USGS Publications Warehouse

Pellerin, Brian A.; Hernes, Peter J.; Saraceno, John Franco; Spencer, Robert G.M.; Bergamaschi, Brian A.

2010-01-01

Although the importance of vascular plant-derived dissolved organic carbon (DOC) in freshwater systems has been studied, the role of leached DOC as precursors of disinfection byproducts (DBPs) during drinking water treatment is not well known. Here we measured the propensity of leachates from four crops and four aquatic macrophytes to form trihalomethanes (THMs)—a regulated class of DBPs—before and after 21 d of microbial degradation. We also measured lignin phenol content and specific UV absorbance (SUVA254) to test the assumption that aromatic compounds from vascular plants are resistant to microbial degradation and readily form DBPs. Leaching solubilized 9 to 26% of total plant carbon, which formed 1.93 to 6.72 mmol THM mol C-1 However, leachate DOC concentrations decreased by 85 to 92% over the 21-d incubation, with a concomitant decrease of 67 to 92% in total THM formation potential. Carbon-normalized THM yields in the residual DOC pool increased by 2.5 times on average, consistent with the preferential uptake of nonprecursor material. Lignin phenol concentrations decreased by 64 to 96% over 21 d, but a lack of correlation between lignin content and THM yields or SUVA254 suggested that lignin-derived compounds are not the source of increased THM precursor yields in the residual DOC pool. Our results indicate that microbial carbon utilization alters THM precursors in ecosystems with direct plant leaching, but more work is needed to identify the specific dissolved organic matter components with a greater propensity to form DBPs and affect watershed management, drinking water quality, and human health.

Thermal Degradation Kinetics Modeling of Benzophenones and Xanthones during High-Temperature Oxidation of Cyclopia genistoides (L.) Vent. Plant Material.

PubMed

Beelders, Theresa; de Beer, Dalene; Joubert, Elizabeth

2015-06-10

Degradation of the major benzophenones, iriflophenone-3-C-glucoside-4-O-glucoside and iriflophenone-3-C-glucoside, and the major xanthones, mangiferin and isomangiferin, of Cyclopia genistoides followed first-order reaction kinetics during high-temperature oxidation of the plant material at 80 and 90 °C. Iriflophenone-3-C-glucoside-4-O-glucoside was shown to be the most thermally stable compound. Isomangiferin was the second most stable compound at 80 °C, while its degradation rate constant was influenced the most by increased temperature. Mangiferin and iriflophenone-3-C-glucoside had comparable degradation rate constants at 80 °C. The thermal degradation kinetic model was subsequently evaluated by subjecting different batches of plant material to oxidative conditions (90 °C/16 h). The model accurately predicted the individual contents of three of the compounds in aqueous extracts prepared from oxidized plant material. The impact of benzophenone and xanthone degradation was reflected in the decreased total antioxidant capacity of the aqueous extracts, as determined using the oxygen radical absorbance capacity and DPPH(•) scavenging assays.

Expanding marine protected areas to include degraded coral reefs.

PubMed

Abelson, A; Nelson, P A; Edgar, G J; Shashar, N; Reed, D C; Belmaker, J; Krause, G; Beck, M W; Brokovich, E; France, R; Gaines, S D

2016-12-01

Marine protected areas (MPAs) are a commonly applied solution to coral reef degradation, yet coral reefs continue to decline worldwide. We argue that expanding the range of MPAs to include degraded reefs (DR-MPA) could help reverse this trend. This approach requires new ecological criteria for MPA design, siting, and management. Rather than focusing solely on preserving healthy reefs, our approach focuses on the potential for biodiversity recovery and renewal of ecosystem services. The new criteria would help identify sites with the highest potential for recovery and the greatest resistance to future threats (e.g., increased temperature and acidification) and sites that contribute to MPA connectivity. The DR-MPA approach is a compliment rather than a substitute for traditional MPA design approaches. We believe that the DR-MPA approach can enhance the natural, or restoration-assisted, recovery of DRs and their ecosystem services; increase total reef area available for protection; promote more resilient and better-connected MPA networks; and improve conditions for human communities dependent on MPA ecosystem services. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

Limited uptake, translocation and enhanced metabolic degradation contribute to glyphosate tolerance in Mucuna pruriens var. utilis plants.

PubMed

Rojano-Delgado, Antonia María; Cruz-Hipolito, Hugo; De Prado, Rafael; Luque de Castro, María Dolores; Franco, Antonio Rodríguez

2012-01-01

Velvet bean (Mucuna pruriens, Fabaceae) plants exhibits an innate, very high resistance (i.e., tolerance) to glyphosate similar to that of plants which have acquired resistance to this herbicide as a trait. We analyzed the uptake of [(14)C]-glyphosate by leaves and its translocation to meristematic tissues, and used scanning electron micrographs to further analyze the cuticle and 3D capillary electrophoresis to investigate a putative metabolism capable of degrading the herbicide. Velvet bean exhibited limited uptake of glyphosate and impaired translocation of the compound to meristematic tissues. Also, for the first time in a higher plant, two concurrent pathways capable of degrading glyphosate to AMPA, Pi, glyoxylate, sarcosine and formaldehyde as end products were identified. Based on the results, the innate tolerance of velvet bean to glyphosate is possibly a result of the combined action of the previous three traits, namely: limited uptake, impaired translocation and enhanced degradation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Cometabolic degradation of trichloroethene by Rhodococcus sp. strain L4 immobilized on plant materials rich in essential oils.

PubMed

Suttinun, Oramas; Müller, Rudolf; Luepromchai, Ekawan

2010-07-01

The cometabolic degradation of trichloroethene (TCE) by Rhodococcus sp. L4 was limited by the loss of enzyme activity during TCE transformation. This problem was overcome by repeated addition of inducing substrates, such as cumene, limonene, or cumin aldehyde, to the cells. Alternatively, Rhodococcus sp. L4 was immobilized on plant materials which contain those inducers in their essential oils. Cumin seeds were the most suitable immobilizing material, and the immobilized cells tolerated up to 68 muM TCE and degraded TCE continuously. The activity of immobilized cells, which had been inactivated partially during TCE degradation, could be reactivated by incubation in mineral salts medium without TCE. These findings demonstrate that immobilization of Rhodococcus sp. L4 on plant materials rich in essential oils is a promising method for efficient cometabolic degradation of TCE.

The plant pathology of native plant restoration

USDA-ARS?s Scientific Manuscript database

Restoration of ecologically degraded sites will benefit from the convergence of knowledge drawn from such disparate and often compartmentalized (and heretofore not widely considered) areas of research as soil microbial ecology, plant pathology and agronomy. Restoration following biological control w...

Soil quality of a degraded urban area

NASA Astrophysics Data System (ADS)

Panico, Speranza; Memoli, Valeria; Maisto, Giulia; De Marco, Anna

2017-04-01

Human activities cause modifications of the soil characteristics, leading to a significant reduction of the soil fertility and quality. The aim of this study was to evaluate the relationships between microbial activity or biomass and chemical characteristics (i.e. heavy metal and organic matter contents) of a degraded urban soil. The study area is located in an urban park (about 10 ha, called Quarantena) near to the Fusaro Lake of Campi Flegrei (Southern Italy); the Park was established in 1953 to shelter animals coming from any place of the Planet and execute veterinary checks before their delivery to different European zoos. In 1997, the park was abandoned and nowadays in it a large amount of urban wastes accumulates. Surface soils (0-10 cm) were sampled at three points: two of them covered by Holm Oak specimens (P1 and P2) and one covered by herbaceous species, particularly legumes (P3). P1 was localized at the border of the park and next to a busy road; P2 at the centre of the Quarantena Park; P3 at a gap area near the Fusaro Lake. The results showed that the soil sampled at P1 showed the highest Cr and Ni concentrations; the soil sampled at P3 had high levels of Cu and Pb, exceeding the threshold values of 100 µg g-1 d.w. fixed by the Italian law for urban soils, probably due to boat traffic, fishing practice and agricultural activities; the soil sampled at P2 had intermediate values of metal concentrations but the highest amount of organic matter (more than 20% d.w.). Despite of metal contamination, P1 and P3 showed higher soil microbial biomass and activity as compared to P2. Therefore, at this site, the organic matter accumulation could be due to the scarce litter degradation. In conclusion, although the studied area was not too large, a wide heterogeneity of soil quality (in terms of the investigated chemical and biological characteristics) was detected, depending on the local human impact.

Plant biomass degrading ability of the coprophilic ascomycete fungus Podospora anserina.

PubMed

Couturier, Marie; Tangthirasunun, Narumon; Ning, Xie; Brun, Sylvain; Gautier, Valérie; Bennati-Granier, Chloé; Silar, Philippe; Berrin, Jean-Guy

2016-01-01

The degradation of plant biomass is a major challenge towards the production of bio-based compounds and materials. As key lignocellulolytic enzyme producers, filamentous fungi represent a promising reservoir to tackle this challenge. Among them, the coprophilous ascomycete Podospora anserina has been used as a model organism to study various biological mechanisms because its genetics are well understood and controlled. In 2008, the sequencing of its genome revealed a great diversity of enzymes targeting plant carbohydrates and lignin. Since then, a large array of lignocellulose-acting enzymes has been characterized and genetic analyses have enabled the understanding of P. anserina metabolism and development on plant biomass. Overall, these research efforts shed light on P. anserina strategy to unlock recalcitrant lignocellulose deconstruction. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparative analysis of diversity and utilization of edible plants in arid and semi-arid areas in Benin.

PubMed

Segnon, Alcade C; Achigan-Dako, Enoch G

2014-12-23

Agrobiodiversity is said to contribute to the sustainability of agricultural systems and food security. However, how this is achieved especially in smallholder farming systems in arid and semi-arid areas is rarely documented. In this study, we explored two contrasting regions in Benin to investigate how agroecological and socioeconomic contexts shape the diversity and utilization of edible plants in these regions. Data were collected through focus group discussions in 12 villages with four in Bassila (semi-arid Sudano-Guinean region) and eight in Boukoumbé (arid Sudanian region). Semi-structured interviews were carried out with 180 farmers (90 in each region). Species richness and Shannon-Wiener diversity index were estimated based on presence-absence data obtained from the focus group discussions using species accumulation curves. Our results indicated that 115 species belonging to 48 families and 92 genera were used to address food security. Overall, wild species represent 61% of edible plants collected (60% in the semi-arid area and 54% in the arid area). About 25% of wild edible plants were under domestication. Edible species richness and diversity in the semi-arid area were significantly higher than in the arid area. However, farmers in the arid area have developed advanced resource-conserving practices compared to their counterparts in the semi-arid area where slash-and-burn cultivation is still ongoing, resulting in natural resources degradation and loss of biodiversity. There is no significant difference between the two areas for cultivated species richness. The interplay of socio-cultural attributes and agroecological conditions explains the diversity of food plants selected by communities. We conclude that if food security has to be addressed, the production and consumption policies must be re-oriented toward the recognition of the place of wild edible plants. For this to happen we suggest a number of policy and strategic decisions as well as research

Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots.

PubMed

Powell, C L; Goltz, M N; Agrawal, A

2014-12-01

Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~1.9mgL(-1), and initial aqueous [CAH] ~150μgL(-1); cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12±0.01 and 0.59±0.07d(-1), respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

[Simulated study of algal fatty acid degradation in hypoxia seawater-sediment interface along China coastal area].

PubMed

Sui, Wei-Wei; Ding, Hai-Bing; Yang, Gui-Peng; Lu, Xiao-Lan; Li, Wen-Juan; Sun, Li-Qun

2013-11-01

Series of laboratory incubation experiments were conducted to simulate degradation of organic matter in sediment-seawater interface in hypoxia enviroments along China coastal area. Under four different redox conditions (oxygen saturation: 100%, 50%, 25% and 0%), degradations of seveal biomarkers originated from Skeletonema costatum, a typical red tide alage along China coastal area were tracked. By analyzing concentrations of four fatty acid biomarkers [14:0, 16:0, 16:1(7) and 20:5] obtained at various sampling time, results showed that their concentrations decreased significantly after 2-3 weeks' incubation. Then, their concentrations changed very slowly or very little. However, degradation of the four fatty acids varied dramatically in different incubation systems. Fatty acids 14:0, 16:1(7) and 20:5 were degraded completely in all incubation systems after two-month incubation, but 25% to 35% of 16:0 was reserved in the systems. Based on multi-G model, degradations of the four fatty acids were quantively described. The results indicated that all four fatty acids had fast-degraded and slow-degraded fractions. Their degradation rate constants (k(av)) ranged from 0.079 to 0.84 d(-1). The fastest degradation of 14:0 and 16:1 (7) occurred under 25% oxygen concentrations. For these two compounds, in the fastest degradation system, their k(av), values were 2.3 folds and 1.7 folds higher than those in the slowest degradation system [50% oxygen saturation for 14:0 and 100% oxygen saturation for 16:1(7)] respectively. The 16:0 was degraded fastest under the anoxic condition and slowest under the 50% oxygen saturation. The ratio of the two k(av)s was 2.1. The k(av)s of 20:5 had a positive relationship with oxygen saturations. Results of this study suggested that besides oxgen saturations, structure and features of organic compounds, roles of microbe in the envrioments and etc. might affect degradations of fatty acids in S. costatum in hypoxia sediment-seawater interface

Plant peroxisomes are degraded by starvation-induced and constitutive autophagy in tobacco BY-2 suspension-cultured cells

PubMed Central

Voitsekhovskaja, Olga V.; Schiermeyer, Andreas; Reumann, Sigrun

2014-01-01

Very recently, autophagy has been recognized as an important degradation pathway for quality control of peroxisomes in Arabidopsis plants. To further characterize the role of autophagy in plant peroxisome degradation, we generated stable transgenic suspension-cultured cell lines of heterotrophic Nicotiana tabacum L. cv. Bright Yellow 2 expressing a peroxisome-targeted version of enhanced yellow fluorescent protein. Indeed, this cell line model system proved advantageous for detailed cytological analyses of autophagy stages and for quantification of cellular peroxisome pools under different culturing conditions and upon inhibitor applications. Complementary biochemical, cytological, and pharmacological analyses provided convincing evidence for peroxisome degradation by bulk autophagy during carbohydrate starvation. This degradation was slowed down by the inhibitor of autophagy, 3-methyladenine (3-MA), but the 3-MA effect ceased at advanced stages of starvation, indicating that another degradation mechanism for peroxisomes might have taken over. 3-MA also caused an increase particularly in peroxisomal proteins and cellular peroxisome numbers when applied under nutrient-rich conditions in the logarithmic growth phase, suggesting a high turnover rate for peroxisomes by basal autophagy under non-stress conditions. Together, our data demonstrate that a great fraction of the peroxisome pool is subject to extensive autophagy-mediated turnover under both nutrient starvation and optimal growth conditions. Our analyses of the cellular pool size of peroxisomes provide a new tool for quantitative investigations of the role of plant peroxisomes in reactive oxygen species metabolism. PMID:25477890

Plant peroxisomes are degraded by starvation-induced and constitutive autophagy in tobacco BY-2 suspension-cultured cells.

PubMed

Voitsekhovskaja, Olga V; Schiermeyer, Andreas; Reumann, Sigrun

2014-01-01

Very recently, autophagy has been recognized as an important degradation pathway for quality control of peroxisomes in Arabidopsis plants. To further characterize the role of autophagy in plant peroxisome degradation, we generated stable transgenic suspension-cultured cell lines of heterotrophic Nicotiana tabacum L. cv. Bright Yellow 2 expressing a peroxisome-targeted version of enhanced yellow fluorescent protein. Indeed, this cell line model system proved advantageous for detailed cytological analyses of autophagy stages and for quantification of cellular peroxisome pools under different culturing conditions and upon inhibitor applications. Complementary biochemical, cytological, and pharmacological analyses provided convincing evidence for peroxisome degradation by bulk autophagy during carbohydrate starvation. This degradation was slowed down by the inhibitor of autophagy, 3-methyladenine (3-MA), but the 3-MA effect ceased at advanced stages of starvation, indicating that another degradation mechanism for peroxisomes might have taken over. 3-MA also caused an increase particularly in peroxisomal proteins and cellular peroxisome numbers when applied under nutrient-rich conditions in the logarithmic growth phase, suggesting a high turnover rate for peroxisomes by basal autophagy under non-stress conditions. Together, our data demonstrate that a great fraction of the peroxisome pool is subject to extensive autophagy-mediated turnover under both nutrient starvation and optimal growth conditions. Our analyses of the cellular pool size of peroxisomes provide a new tool for quantitative investigations of the role of plant peroxisomes in reactive oxygen species metabolism.

ANTHROPOGENIC NUTRIENT INPUT AND ITS INFLUENCE ON PLANT COMPETITIVE OUTCOMES: IMPLICATIONS FOR HABITAT DEGRADATION AND COMMUNITY SHIFTS

EPA Science Inventory

By taking a multifactorial approach, the study will document complex aquatic plant responses to NPS nutrient contamination, providing fundamental insight into the broader impacts of environmental degradation, its impacts on plant function, and implications for ecosystem ser...

Assessment and restoring soil functionality in degraded areas of organic vineyards. The preliminary results of the ReSolVe project in Italy

NASA Astrophysics Data System (ADS)

Priori, Simone; Agnelli, Alessandro; Castaldini, Maurizio; D'Avino, Lorenzo; D'Errico, Giada; Gagnarli, Elena; Giudi, Silvia; Goggioli, Donatella; Lagomarsino, Alessandra; Landi, Silvia; Leprini, Marco; Pellegrini, Sergio; Perria, Rita; Puccioni, Sergio; Simoni, Sauro; Storchi, Paolo; Valboa, Giuseppe; Zombardo, Alessandra; Costantini, Edoardo

2016-04-01

homogeneous patterns within the experimental plots. Nematode abundance, taxa richness and maturity (MI) and plant parasitic (PPI) indices were higher in non-degraded than degraded areas, but differences were not significant. Grapevines in degraded areas of both farms showed less vegetative vigour and significantly lower values in the SPAD colour index. The yield and the weight of the grape bunches and berries were greater in the not degraded. The grapes of degraded areas at harvest had instead a sugar content significantly higher (on average +2.5°Brix). The restoration techniques and the monitoring methodologies developed and tested during the ReSolVe project will be described in specific final guidelines. The restoration techniques will be accessible for all the European farmers and will be low cost and environmental-friendly. A protocol of analyses and measurements between the all partners will allow an effective and comparable monitoring of vineyard ecosystemic functioning in European countries. Keywords: organic, viticulture, soil functionality, biodiversity, soil management Aknowledgements: Financial support for this project is provided by funding bodies within the FP7 ERA-Net CORE Organic Plus, and cofunds from the European Commission.

[Accumulation and degradation of organochorine pesticides in shellfish culture environment in Xiamen sea area].

PubMed

Zhong, Shuo-liang; Dong, Li-ming

2011-09-01

By using GC-ECD, the concentrations of organochlorine pesticides hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in the shellfish culture environment (sea water, sediments, and culture-shellfishes) in Xiamen sea area were analyzed, and the accumulation and degradation patterns of the HCH and DDT were preliminarily approached. In the sea area, there existed remarkable differences in the accumulation and degradation of HCH and DDT among different shellfish culture environments, being mostly associated with the habitation environment and physiological life habits of shellfish. The accumulated HCH isomers (Rx > 1) were mainly beta-HCH, delta-HCH, and gamma-HCH, whereas the degraded HCH isomers (Rx < 1) were mainly alpha-HCH. The ratio of alpha-HCH to gamma-HCH was less than or equal to 1.0, suggesting that the HCH was come from industrial HCH and lindane, most of the HCH had remained in the culture environment for a longer time, and a small amount of lindane was imported. The DDT in the sea water was aerobically degraded, its main degradation product was DDE, and the ratios of (DDD+DDE) to DDTs (p,p-DDE+p,p-DDD+o,p-DDT+p,p-DDT) was less than 0.5, whereas the DDT in sediments and shellfishes was anaerobically degraded, its main degradation product was DDD, and the ratios of (DDD+DDE) to DDTs was greater than 0.5, suggesting that there was a small amount of DDT newly imported in the sea water, and most DDT in sediments and shellfishes were already degraded and transformed into DDD and DDE. There were definite differences in the degradation rates of HCH isomers in the culture environment, suggesting the conformational change of HCH in its transformation processes in the shellfish culture ecosystem.

Enhanced degradation of chlorpyrifos in rice (Oryza sativa L.) by five strains of endophytic bacteria and their plant growth promotional ability.

PubMed

Feng, Fayun; Ge, Jing; Li, Yisong; He, Shuang; Zhong, Jianfeng; Liu, Xianjing; Yu, Xiangyang

2017-10-01

Endophytic bacteria reside in plant tissues, such as roots, stems, leaves and seeds. Most of them can stimulate plant growth or alleviate phytotoxicity of pollutants. There are handful species with dual functions stimulating plant growth and degrading pollutants have been reported. Five endophytic bacteria were isolated from chlorpyrifos (CP) treated rice plants and identified as Pseudomonas aeruginosa strain RRA, Bacillus megaterium strain RRB, Sphingobacterium siyangensis strain RSA, Stenotrophomonas pavanii strain RSB and Curtobacterium plantarum strain RSC according to morphological characteristics, physiological and biochemical tests, and 16S rDNA phylogeny. All of them possessed some plant growth promotional traits, including indole acetic acid and siderophore production, secretion of phosphate solubilization and 1-aminocyclopropane-1-carboxylate deaminase. The bacteria were marked with the green fluorescent protein (gfp) gene and successfully colonized into rice plants. All isolates were able to degrade CP in vitro and in vivo. The five isolates degraded more than 90% of CP in 24 h when the initial concentration was lower than 5 mg/L. CP degradation was significantly enhanced in the infested rice plants and rice grains. The final CP residual was reduced up to 80% in the infested rice grains compared to the controls. The results indicate that these isolates are promising bio-inoculants for the removal or detoxification of CP residues in rice plants and grains. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correction: Comparative analysis of fungal genomes reveals different plant cell wall degrading capacity in fungi

PubMed Central

2014-01-01

Abstract The version of this article published in BMC Genomics 2013, 14: 274, contains 9 unpublished genomes (Botryobasidium botryosum, Gymnopus luxurians, Hypholoma sublateritium, Jaapia argillacea, Hebeloma cylindrosporum, Conidiobolus coronatus, Laccaria amethystina, Paxillus involutus, and P. rubicundulus) downloaded from JGI website. In this correction, we removed these genomes after discussion with editors and data producers whom we should have contacted before downloading these genomes. Removing these data did not alter the principle results and conclusions of our original work. The relevant Figures 1, 2, 3, 4 and 6; and Table 1 have been revised. Additional files 1, 3, 4, and 5 were also revised. We would like to apologize for any confusion or inconvenience this may have caused. Background Fungi produce a variety of carbohydrate activity enzymes (CAZymes) for the degradation of plant polysaccharide materials to facilitate infection and/or gain nutrition. Identifying and comparing CAZymes from fungi with different nutritional modes or infection mechanisms may provide information for better understanding of their life styles and infection models. To date, over hundreds of fungal genomes are publicly available. However, a systematic comparative analysis of fungal CAZymes across the entire fungal kingdom has not been reported. Results In this study, we systemically identified glycoside hydrolases (GHs), polysaccharide lyases (PLs), carbohydrate esterases (CEs), and glycosyltransferases (GTs) as well as carbohydrate-binding modules (CBMs) in the predicted proteomes of 94 representative fungi from Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota. Comparative analysis of these CAZymes that play major roles in plant polysaccharide degradation revealed that fungi exhibit tremendous diversity in the number and variety of CAZymes. Among them, some families of GHs and CEs are the most prevalent CAZymes that are distributed in all of the fungi analyzed

Cometabolic Degradation of Trichloroethene by Rhodococcus sp. Strain L4 Immobilized on Plant Materials Rich in Essential Oils▿ †

PubMed Central

Suttinun, Oramas; Müller, Rudolf; Luepromchai, Ekawan

2010-01-01

The cometabolic degradation of trichloroethene (TCE) by Rhodococcus sp. L4 was limited by the loss of enzyme activity during TCE transformation. This problem was overcome by repeated addition of inducing substrates, such as cumene, limonene, or cumin aldehyde, to the cells. Alternatively, Rhodococcus sp. L4 was immobilized on plant materials which contain those inducers in their essential oils. Cumin seeds were the most suitable immobilizing material, and the immobilized cells tolerated up to 68 μM TCE and degraded TCE continuously. The activity of immobilized cells, which had been inactivated partially during TCE degradation, could be reactivated by incubation in mineral salts medium without TCE. These findings demonstrate that immobilization of Rhodococcus sp. L4 on plant materials rich in essential oils is a promising method for efficient cometabolic degradation of TCE. PMID:20472723

Assessment of land degradation and its spatial and temporal variation in Beijing surrounding area

NASA Astrophysics Data System (ADS)

Li, Shuang; Dong, Suocheng; Zhang, Xiaojun; Zhiqiang, Gao

2005-08-01

The indulgence in willful persecution of sandstorm had made great attention of many countries around the world. Chinese government and the Chinese academy of science going with some other countries have devoted a large amount of vigor to study the crucial environment problem. Due to the main source areas of sandstorm all located in the arid and semi-arid regions where there have great area, hard natural condition and bad traffic condition, it's very difficult to accomplish source area and the reason of sandstorm. For this destination, a international cooperation organization has been established to clarify the occur mechanism, transfer process and the following environment impact of sandstorm. The organization includes many researchers come form USA, Japan, Korea, and so on. Beijing surrounding area is one of the main sandstorm sources in recent years. In order to understand fully of the sandstorm form and development, we analyzed the land use degradation of Beijing surrounding area during the last ten years. 71 scenes Landsat TM/ETM, 611 scenes DRG and DEM data had been processed in our study. This paper made a detail describe of using Landsat image data and high resolution DEM data to construe the soil erosion and vegetation degenerate. The result shows that the irrational human activities and land use style are the main factors of land use degradation. In case of Beijing surrounding area, the land degradation directly impacted the frequency and intensity of sand & dust storm in Northern China. The case study region of Beijing surrounding area includes 51 counties that belong to three provinces and autonomous regions.

Isolation of bacterial strains able to degrade biphenyl, diphenyl ether and the heat transfer fluid used in thermo-solar plants.

PubMed

Blanco-Moreno, Rafael; Sáez, Lara P; Luque-Almagro, Víctor M; Roldán, M Dolores; Moreno-Vivián, Conrado

2017-03-25

Thermo-solar plants use eutectic mixtures of diphenyl ether (DE) and biphenyl (BP) as heat transfer fluid (HTF). Potential losses of HTF may contaminate soils and bioremediation is an attractive tool for its treatment. DE- or BP-degrading bacteria are known, but up to now bacteria able to degrade HTF mixture have not been described. Here, five bacterial strains which are able to grow with HTF or its separate components DE and BP as sole carbon sources have been isolated, either from soils exposed to HTF or from rhizospheric soils of plants growing near a thermo-solar plant. The organisms were identified by 16S rRNA gene sequencing as Achromobacter piechaudii strain BioC1, Pseudomonas plecoglossicida strain 6.1, Pseudomonas aeruginosa strains HBD1 and HBD3, and Pseudomonas oleovorans strain HBD2. Activity of 2,3-dihydroxybiphenyl dioxygenase (BphC), a key enzyme of the biphenyl upper degradation pathway, was detected in all isolates. Pseudomonas strains almost completely degraded 2000ppm HTF after 5-day culture, and even tolerated and grew in the presence of 150,000ppm HTF, being suitable candidates for in situ soil bioremediation. Degradation of both components of HTF is of particular interest since in the DE-degrader Sphingomonas sp. SS3, growth on DE or benzoate was strongly inhibited by addition of BP. Copyright © 2016 Elsevier B.V. All rights reserved.

Isolation, plant colonization potential, and phenanthrene degradation performance of the endophytic bacterium Pseudomonas sp. Ph6-gfp

PubMed Central

Sun, Kai; Liu, Juan; Gao, Yanzheng; Jin, Li; Gu, Yujun; Wang, Wanqing

2014-01-01

This investigation provides a novel method of endophyte-aided removal of polycyclic aromatic hydrocarbons (PAHs) from plant bodies. A phenanthrene-degrading endophytic bacterium Pseudomonas sp. Ph6 was isolated from clover (Trifolium pratense L.) grown in a PAH-contaminated site. After being marked with the GFP gene, the colonization and distribution of strain Ph6-gfp was directly visualized in plant roots, stems, and leaves for the first time. After ryegrass (Lolium multiflorum Lam.) roots inoculation, strain Ph6-gfp actively and internally colonized plant roots and transferred vertically to the shoots. Ph6-gfp had a natural capacity to cope with phenanthrene in vitro and in planta. Ph6-gfp degraded 81.1% of phenanthrene (50 mg·L−1) in a culture solution within 15 days. The inoculation of plants with Ph6-gfp reduced the risks associated with plant phenanthrene contamination based on observations of decreased concentration, accumulation, and translocation factors of phenanthrene in ryegrass. Our results will have important ramifications in the assessment of the environmental risks of PAHs and in finding ways to circumvent plant PAH contamination. PMID:24964867

Traditional uses of plants in a rural community of Mozambique and possible links with Miombo degradation and harvesting sustainability

PubMed Central

2014-01-01

Background Miombo woodlands play an important role in the livelihood of people living in sub-equatorial African countries, contributing to satisfy basic human needs such as food, medicine, fuelwood and building materials. However, over-exploitation of plant resources and unsustainable harvest practices can potentially degrade forests. The aim of this study was to document the use of Miombo plant products, other than medicinal plants, in local communities, within a wider framework in which we discussed possible links between traditional uses and conservation status of the used species and of the whole Miombo environment. Methods Fieldwork took place in four communities of Muda-Serração, central Mozambique. We conducted semi-structured interviews with 52 informants about their knowledge, use and harvesting practices of useful plants. A survey on local Miombo vegetation was also carried out in order to assess abundance and distribution of useful woody plants cited in the interviews in areas exposed to different exploitation rates. A Conservation Priority index was also applied to rank conservation values of each used woody species. Results Ninety-eight plants cited by the informants were botanically identified. The most relevant general category was represented by food plants (45 species), followed by handicraft plants (38 species) and domestic plants (37 species). Among the 54 woody species observed in vegetation plots, 52% were cited as useful in the interviews. Twenty-six woody species found in ‘natural’ Miombo areas were not found in ‘degraded’ ones: of these, 46% were cited in the interviews (58% in the food category, 50% in the handicraft category, 25% in the domestic category and 8% in the fishing category). Results of conservation ranking showed that 7 woody species deserve conservation priority in the investigated area. Conclusions This study shows that the communities investigated rely heavily on local forest products for their daily subsistence

Fragility Analysis Methodology for Degraded Structures and Passive Components in Nuclear Power Plants - Illustrated using a Condensate Storage Tank

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nie, J.; Braverman, J.; Hofmayer, C.

2010-06-30

The Korea Atomic Energy Research Institute (KAERI) is conducting a five-year research project to develop a realistic seismic risk evaluation system which includes the consideration of aging of structures and components in nuclear power plants (NPPs). The KAERI research project includes three specific areas that are essential to seismic probabilistic risk assessment (PRA): (1) probabilistic seismic hazard analysis, (2) seismic fragility analysis including the effects of aging, and (3) a plant seismic risk analysis. Since 2007, Brookhaven National Laboratory (BNL) has entered into a collaboration agreement with KAERI to support its development of seismic capability evaluation technology for degraded structuresmore » and components. The collaborative research effort is intended to continue over a five year period. The goal of this collaboration endeavor is to assist KAERI to develop seismic fragility analysis methods that consider the potential effects of age-related degradation of structures, systems, and components (SSCs). The research results of this multi-year collaboration will be utilized as input to seismic PRAs. In the Year 1 scope of work, BNL collected and reviewed degradation occurrences in US NPPs and identified important aging characteristics needed for the seismic capability evaluations. This information is presented in the Annual Report for the Year 1 Task, identified as BNL Report-81741-2008 and also designated as KAERI/RR-2931/2008. The report presents results of the statistical and trending analysis of this data and compares the results to prior aging studies. In addition, the report provides a description of U.S. current regulatory requirements, regulatory guidance documents, generic communications, industry standards and guidance, and past research related to aging degradation of SSCs. In the Year 2 scope of work, BNL carried out a research effort to identify and assess degradation models for the long-term behavior of dominant materials that are

Halotolerant microbial consortia able to degrade highly recalcitrant plant biomass substrate.

PubMed

Cortes-Tolalpa, Larisa; Norder, Justin; van Elsas, Jan Dirk; Falcao Salles, Joana

2018-03-01

The microbial degradation of plant-derived compounds under salinity stress remains largely underexplored. The pretreatment of lignocellulose material, which is often needed to improve the production of lignocellulose monomers, leads to high salt levels, generating a saline environment that raises technical considerations that influence subsequent downstream processes. Here, we constructed halotolerant lignocellulose degrading microbial consortia by enriching a salt marsh soil microbiome on a recalcitrant carbon and energy source, i.e., wheat straw. The consortia were obtained after six cycles of growth on fresh substrate (adaptation phase), which was followed by four cycles on pre-digested (highly-recalcitrant) substrate (stabilization phase). The data indicated that typical salt-tolerant bacteria made up a large part of the selected consortia. These were "trained" to progressively perform better on fresh substrate, but a shift was observed when highly recalcitrant substrate was used. The most dominant bacteria in the consortia were Joostella marina, Flavobacterium beibuense, Algoriphagus ratkowskyi, Pseudomonas putida, and Halomonas meridiana. Interestingly, fungi were sparsely present and negatively affected by the change in the substrate composition. Sarocladium strictum was the single fungal strain recovered at the end of the adaptation phase, whereas it was deselected by the presence of recalcitrant substrate. Consortia selected in the latter substrate presented higher cellulose and lignin degradation than consortia selected on fresh substrate, indicating a specialization in transforming the recalcitrant regions of the substrate. Moreover, our results indicate that bacteria have a prime role in the degradation of recalcitrant lignocellulose under saline conditions, as compared to fungi. The final consortia constitute an interesting source of lignocellulolytic haloenzymes that can be used to increase the efficiency of the degradation process, while decreasing

Cross-border cooperation potential in fostering redevelopment of degraded border areas - a case study approach.

NASA Astrophysics Data System (ADS)

Alexandre Castanho, Rui; Ramírez, Beatriz; Loures, Luis; Fernández-Pozo, Luis; Cabezas, José

2017-04-01

Border interactions have reached unprecedented levels in recent decades, not only due to their potential for territorial integration but also considering their role in supranational processes, such as landscape reclamation, infrastructure development and land use planning on European territory. In this scenario, successful examples related to the redevelopment of degraded areas have been showing positive impacts at several levels, such as the social, economic, environmental and aesthetic ones which have ultimately related this process, positively, to sustainability issues. However, concerning to border areas, and due to their inherent legislative and bureaucratic conflicts, the intervention in these areas is more complex. Still, and taking into account previously developed projects and strategies of cross-border cooperation (CBC) in European territory it is possible to identified that the definition of common master plans and common objectives are critical issues to achieve the desired territorial success. Additionally, recent studies have put forward some noteworthy ideas highlighting that it is possible to establish a positive correlation between CBC processes and an increasing redevelopment of degraded border areas, with special focus on the reclamation of derelict landscapes fostering soil reuse and redevelopment. The present research, throughout case study analysis at the Mediterranean level - considering case studies from Portugal, Spain, Monaco and Italy - which presents specific data on border landscape redevelopment, enables us to conclude that CBC processes have a positive influence on the potential redevelopment of degraded border areas, considering not only urban but also rural land. Furthermore, this paper presents data obtained through a public participation process which highlights that these areas present a greater potential for landscape reclamation, fostering resource sustainability and sustainable growth. Keywords: Spatial planning; Land

The plant hopper Issus coleoptratus can detoxify phloem sap saponins including the degradation of the terpene core

PubMed Central

Himmelsbach, Markus; Weth, Agnes; Böhme, Christine; Schwarz, Martin; Bräunig, Peter; Baumgartner, Werner

2016-01-01

ABSTRACT Issus coleoptratus is a small plant hopper which mainly feeds on the phloem sap from ivy. Although all parts of ivy are poisonous as the plant contains saponins, especially hederasaponins, I. coleoptratus can cope with the poison. In contrast to other animals like the stick insect Carausius morosus which accumulates saponins in its body, I. coleoptratus can degrade and disintegrate not only the saponins but even the genines, i.e. the triterpene core of the substances. This is perhaps made possible by a specialised midgut and/or the salivary glands. When the glands and the gut are dissected and added to saponins in solution, the saponins, including the genines, are degraded ex vivo. PMID:26863940

Restoration of Degraded Soil in the Nanmangalam Reserve Forest with Native Tree Species: Effect of Indigenous Plant Growth-Promoting Bacteria

PubMed Central

Ramachandran, Andimuthu; Radhapriya, Parthasarathy

2016-01-01

Restoration of a highly degraded forest, which had lost its natural capacity for regeneration, was attempted in the Nanmangalam Reserve Forest in Eastern Ghats of India. In field experiment, 12 native tree species were planted. The restoration included inoculation with a consortium of 5 native plant growth-promoting bacteria (PGPB), with the addition of small amounts of compost and a chemical fertilizer (NPK). The experimental fields were maintained for 1080 days. The growth and biomass varied depending on the plant species. All native plants responded well to the supplementation with the native PGPB. The plants such as Pongamia pinnata, Tamarindus indica, Gmelina arborea, Wrightia tinctoria, Syzygium cumini, Albizia lebbeck, Terminalia bellirica, and Azadirachta indica performed well in the native soil. This study demonstrated, by using native trees and PGPB, a possibility to restore the degraded forest. PMID:27195310

Restoration of Degraded Soil in the Nanmangalam Reserve Forest with Native Tree Species: Effect of Indigenous Plant Growth-Promoting Bacteria.

PubMed

Ramachandran, Andimuthu; Radhapriya, Parthasarathy

Restoration of a highly degraded forest, which had lost its natural capacity for regeneration, was attempted in the Nanmangalam Reserve Forest in Eastern Ghats of India. In field experiment, 12 native tree species were planted. The restoration included inoculation with a consortium of 5 native plant growth-promoting bacteria (PGPB), with the addition of small amounts of compost and a chemical fertilizer (NPK). The experimental fields were maintained for 1080 days. The growth and biomass varied depending on the plant species. All native plants responded well to the supplementation with the native PGPB. The plants such as Pongamia pinnata, Tamarindus indica, Gmelina arborea, Wrightia tinctoria, Syzygium cumini, Albizia lebbeck, Terminalia bellirica, and Azadirachta indica performed well in the native soil. This study demonstrated, by using native trees and PGPB, a possibility to restore the degraded forest.

Activating Intrinsic Carbohydrate-Active Enzymes of the Smut Fungus Ustilago maydis for the Degradation of Plant Cell Wall Components

PubMed Central

Geiser, Elena; Reindl, Michèle; Blank, Lars M.; Feldbrügge, Michael

2016-01-01

ABSTRACT The microbial conversion of plant biomass to valuable products in a consolidated bioprocess could greatly increase the ecologic and economic impact of a biorefinery. Current strategies for hydrolyzing plant material mostly rely on the external application of carbohydrate-active enzymes (CAZymes). Alternatively, production organisms can be engineered to secrete CAZymes to reduce the reliance on externally added enzymes. Plant-pathogenic fungi have a vast repertoire of hydrolytic enzymes to sustain their lifestyle, but expression of the corresponding genes is usually highly regulated and restricted to the pathogenic phase. Here, we present a new strategy in using the biotrophic smut fungus Ustilago maydis for the degradation of plant cell wall components by activating its intrinsic enzyme potential during axenic growth. This fungal model organism is fully equipped with hydrolytic enzymes, and moreover, it naturally produces value-added substances, such as organic acids and biosurfactants. To achieve the deregulated expression of hydrolytic enzymes during the industrially relevant yeast-like growth in axenic culture, the native promoters of the respective genes were replaced by constitutively active synthetic promoters. This led to an enhanced conversion of xylan, cellobiose, and carboxymethyl cellulose to fermentable sugars. Moreover, a combination of strains with activated endoglucanase and β-glucanase increased the release of glucose from carboxymethyl cellulose and regenerated amorphous cellulose, suggesting that mixed cultivations could be a means for degrading more complex substrates in the future. In summary, this proof of principle demonstrates the potential applicability of activating the expression of native CAZymes from phytopathogens in a biocatalytic process. IMPORTANCE This study describes basic experiments that aim at the degradation of plant cell wall components by the smut fungus Ustilago maydis. As a plant pathogen, this fungus contains a

Applying a dryland degradation framework for rangelands: the case of Mongolia.

PubMed

Jamsranjav, C; Reid, R S; Fernández-Giménez, M E; Tsevlee, A; Yadamsuren, B; Heiner, M

2018-04-01

Livestock-caused rangeland degradation remains a major policy concern globally and the subject of widespread scientific study. This concern persists in part because it is difficult to isolate the effects of livestock from climate and other factors that influence ecosystem conditions. Further, degradation studies seldom use multiple plant and soil indicators linked to a clear definition of and ecologically grounded framework for degradation assessment that distinguishes different levels of degradation. Here, we integrate two globally applicable rangeland degradation frameworks and apply them to a broad-scale empirical data set for the country of Mongolia. We compare our assessment results with two other recent national rangeland degradation assessments in Mongolia to gauge consistency of findings across assessments and evaluate the utility of our framework. We measured livestock-use impacts across Mongolia's major ecological zones: mountain and forest steppe, eastern steppe, steppe, and desert steppe. At 143 sites in 36 counties, we measured livestock-use and degradation indicators at increasing distances from livestock corrals in winter-grazed pastures. At each site, we measured multiple indicators linked to our degradation framework, including plant cover, standing biomass, palatability, species richness, forage quality, vegetation gaps, and soil surface characteristics. Livestock use had no effect on soils, plant species richness, or standing crop biomass in any ecological zone, but subtly affected plant cover and palatable plant abundance. Livestock effects were strongest in the steppe zone, moderate in the desert steppe, and limited in the mountain/forest and eastern steppes. Our results aligned closely with those of two other recent country-wide assessments, suggesting that our framework may have widespread application. All three assessments found that very severe and irreversible degradation is rare in Mongolia (1-18% of land area), with most rangelands

Linking runoff and erosion dynamics to nutrient fluxes in a degrading dryland landscape

NASA Astrophysics Data System (ADS)

Michaelides, Katerina; Lister, Debbie; Wainwright, John; Parsons, Anthony J.

2012-12-01

Current theories of land degradation assume that shifts in vegetation communities result in changes to the rates and patterns of water and sediment movement, which are vectors of nutrient redistribution. This nutrient redistribution is hypothesized to reinforce, through positive feedbacks, progressive vegetation changes toward a more degraded ecosystem. A key component of this theory, which is currently poorly resolved, is the relative role of runoff and erosion in driving nutrient fluxes from different vegetation types. We address this gap through a series of field-based, rainfall-simulation experiments designed to explore plant-level dynamics of runoff- and erosion-driven nutrient fluxes of N, P and K species. Our results highlight important linkages between physical and biogeochemical processes that are controlled by plant structure. We found that: 1) the magnitude of sediment-bound nutrient export is determined by the grain-size distribution of the eroded sediment and the total sediment yield; 2) the partitioning of nutrients in dissolved and sediment-bound form is determined by the availability and concentration of different nutrient species in the soil or rainfall; 3) these processes varied according to vegetation type and resulted in stark differences between degrading and invading plant communities. Specifically, we observed that grassland areas consistently exported the highest yields of sediment-bound N, P and K despite producing similar erosion rates to shrub and intershrub areas. Our results have implications for better understanding how grassland areas are being replaced by shrubs and provide insights into the mechanisms of continuing land degradation in drylands.

Stress tolerance of soil fungal communities from native Atlantic forests, reforestations, and a sand mining degraded area.

PubMed

Ferreira, Paulo C; Pupin, Breno; Rangel, Drauzio E N

2018-06-01

Microorganisms are essential to the functionality of the soil, particularly in organic matter decomposition and nutrient cycling, which regulate plant productivity and shape the soil structure. However, biotic and abiotic stresses greatly disrupt soil fungal communities and, thereby, disturb the ecosystem. This study quantified seasonal tolerances to UV-B radiation and heat of fungal communities, which could be cultured, found in soil from two native Atlantic forest fragments called F1 and F2, five reforested areas (RA) planted in 1994, 1997, 2004, 2007, and 2009 with native species of the Atlantic forest, and one sand mining degraded soil (SMDS). The cold activity of the soil fungal communities (FC) from the eight different areas was also studied. Higher tolerance to UV-B radiation and heat was found in the FC from the SMDS and the 2009RA, where the incidence of heat and UV radiation from sun was more intense, which caused selection for fungal taxa that were more UV-B and heat tolerant in those areas. Conversely, the FC from the native forests and older reforested sites were very susceptible to heat and UV-B radiation. The cold activity of the soil FC from different areas of the study showed an erratic pattern of responses among the sampling sites. Little difference in tolerance to UV-B radiation and heat was found among the FC of soil samples collected in different seasons; in general soil FC collected in winter were less tolerant to UV-B radiation, but not for heat. In conclusion, FC from SMDS soil that receive intense heat and UV radiation, as well as with low nutrient availability, were more tolerant to both UV-B radiation and heat. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Designation of less favorable areas by the regionalization of soil degradation on various spatial scales

NASA Astrophysics Data System (ADS)

Pásztor, L.; Szabó, J.; Bakacsi, Zs.; Laborczi, A.

2009-04-01

One of the main objectives of the EU's Common Agricultural Policy is to encourage maintaining agricultural production in less favorable areas (LFA) in order (among others) to sustain agricultural production and use natural resources, in such a way to secure both stable production and income to farmers and to protect the environment. LFA assignment has both ecological and severe economical aspects. Delimitation of LFAs can be carried out by using biophysical diagnostic criteria on low soil productivity and poor climate conditions. Identification of low-productivity areas requires regionalization of soil functions related to food and other biomass production. This process can be carried out in different scales from national to local level, but always requires map-based pedological and further environmental information with appropriate spatial resolution. For the regionalization of less productive areas in national scale a functional approach was used which integrates the knowledge on soil degradation processes in nationwide level. Specific soil threats were classified into ranked categories. Supposing (quasi)uniform distribution of vulnerability measure along these classes, we introduced a "standardized" value as a ratio of the class order to the maximum class order expressed in percentage. For the overall spatial characterization of degradation status, spatial information was integrated in a result map by summarizing the degradation specific "standardized" cell values. This map in one hand has been used for the delineation of soil degradation regions. On the other hand appropriate spatial aggregation of index values on geographical and administrative regions is suitable for their quantitative comparison thus they can be ranked and this feature can be used for the identification of less favorable areas. At the more detailed, county level the Digital Kreybig Soil Information System was used as a tool of the regionalization of soil functions related to soil

Terrestrial Particulate Organic Matter Degradation in Estuarine and Coastal Areas: Coupling Lipid Tracers and Molecular Tools to Better Understand Deltaic Biogeochemical Cycles

NASA Astrophysics Data System (ADS)

Galeron, M. A.; Volkman, J. K.; Rontani, J. F.; Radakovitch, O.; Charriere, B.; Amiraux, R.

2016-02-01

Deltaic and coastal areas have been studied extensively worldwide, due to their high economic and ecosystemic value. It was long thought that terrestrial particulate organic matter (TPOM) degraded during river transport was refractory to further degradation upon its arrival at sea. But studies on coastal sediments and in the Mackenzie delta (Canada) showed that, on the contrary, TPOM was undergoing intense degradation upon reaching seawater. In order to generalize these results to worldwide river basins, we propose to trace degradation processes impacting TPOM during in-stream transport as well as coastal distribution. We selected the Rhône River (France) for its differences with the Mackenzie River (latitude, temperature, coastal salinity) and carefully researched lipid tracers to help us pinpoint both the origin of the POM and the degradative processes undergone. Betulin, α-/β-amyrins, dehydroabietic acid, sitosterol and their specific degradation products were selected. While the Rhône delta has been studied for decades, there is very little research on its in-stream processes, and how they can be linked with coastal cycles and fluxes. Coupling new specific lipid tracers especially selected for the monitoring of higher plant degradation and molecular biology tools, we were able to better trace the origin of TPOM transported along the Rhône River, as well as better understand its degradation state in the river, the delta, and upon its arrival at sea. We show here that autoxidation (free radical induced oxidation), long overlooked, is a major degradation process impacting TPOM transported along the Rhone River, and is even more intense upon the arrival of TPOM at sea. Salinity, metal ion desorption, bacterial and biochemical activity are amongst the factors studied as inducers of such an intense degradation. This understanding is crucial if we want a truly extensive knowledge of terrestrial particulate organic matter transport and deposition, as well as

Potential for plant growth promotion by a consortium of stress-tolerant 2,4-dinitrotoluene-degrading bacteria: isolation and characterization of a military soil

PubMed Central

Thijs, Sofie; Weyens, Nele; Sillen, Wouter; Gkorezis, Panagiotis; Carleer, Robert; Vangronsveld, Jaco

2014-01-01

The presence of explosives in soils and the interaction with drought stress and nutrient limitation are among the environmental factors that severely affect plant growth on military soils. In this study, we seek to isolate and identify the cultivable bacteria of a 2,4-dinitrotoluene (DNT) contaminated soil (DS) and an adjacent grassland soil (GS) of a military training area aiming to isolate new plant growth-promoting (PGP) and 2,4-DNT-degrading strains. Metabolic profiling revealed disturbances in Ecocarbon use in the bare DS; isolation of cultivable strains revealed a lower colony-forming-unit count and a less diverse community associated with DS in comparison with GS. New 2,4-DNT-tolerant strains were identified by selective enrichments, which were further characterized by auxanography for 2,4-DNT use, resistance to drought stress, cold, nutrient starvation and PGP features. By selecting multiple beneficial PGP and abiotic stress-resistant strains, efficient 2,4-DNT-degrading consortia were composed. After inoculation, consortium UHasselt Sofie 3 with seven members belonging to Burkholderia, Variovorax, Bacillus, Pseudomonas and Ralstonia species was capable to successfully enhance root length of Arabidopsis under 2,4-DNT stress. After 9 days, doubling of main root length was observed. Our results indicate that beneficial bacteria inhabiting a disturbed environment have the potential to improve plant growth and alleviate 2,4-DNT stress. PMID:24467368

A prediction model of signal degradation in LMSS for urban areas

NASA Technical Reports Server (NTRS)

Matsudo, Takashi; Minamisono, Kenichi; Karasawa, Yoshio; Shiokawa, Takayasu

1993-01-01

A prediction model of signal degradation in a Land Mobile Satellite Service (LMSS) for urban areas is proposed. This model treats shadowing effects caused by buildings statistically and can predict a Cumulative Distribution Function (CDF) of signal diffraction losses in urban areas as a function of system parameters such as frequency and elevation angle and environmental parameters such as number of building stories and so on. In order to examine the validity of the model, we compared the percentage of locations where diffraction losses were smaller than 6 dB obtained by the CDF with satellite visibility measured by a radiometer. As a result, it was found that this proposed model is useful for estimating the feasibility of providing LMSS in urban areas.

Argan woodlands in South Morocco as an area of conflict between degradation and sustainable land use

NASA Astrophysics Data System (ADS)

Kirchhoff, Mario; Kagermeier, Andreas; Ries, Johannes B.

2016-04-01

The Argan woodlands are endemic for South Morocco and prone to degradation through expanding and intensifying agriculture and overgrazing. Unvegetated areas extend further due to degradation of soil and vegetation. Here infiltration is less than on vegetated areas, while runoff and soil erosion increase. The sale of the highly valuable oil, gained from the seeds of the argan tree, can be seen as an economic alternative for the region and a chance of survival for the argan woodlands. With the introduction of women's cooperatives for the production and sale of the oil, the Gesellschaft für Technische Zusammenarbeit (GTZ, Association for Technical Cooperation) hoped to halt argan degradation from 1995 to 2002. The effects of this approach shall be studied in a proposed DFG-project. The erosion gradient between soils under canopy cover and intertree areas in varying stages of degradation will be at the center of the analysis. Insight into onsite and offsite degradation shall be gained through the measurement of runoff and erosion rates, which lead to rill and gully erosion downslope. Measurements of soil chemical and physical properties might also help indicate when an argan woodland can be classified as natural. Furthermore to be studied are the effects of the new found value of the Argan woodlands among the local population with focus on regional tourism and a possible reduction of grazing pressure. Sustainable soil management in combination with the needs of the local population is essential for a sustainable land use in the region.

Use of phytoproductivity data in the choice of native plant species to restore a degraded coal mining site amended with a stabilized industrial organic sludge.

PubMed

Chiochetta, Claudete G; Toumi, Hela; Böhm, Renata F S; Engel, Fernanda; Poyer-Radetski, Gabriel; Rörig, Leonardo R; Adani, Fabrizio; Radetski, Claudemir M

2017-11-01

Coal mining-related activities result in a degraded landscape and sites associated with large amounts of dumped waste material. The arid soil resulting from acid mine drainage affects terrestrial and aquatic ecosystems, and thus, site remediation programs must be implemented to mitigate this sequential deleterious processes. A low-cost alternative material to counterbalance the affected physico-chemical-microbiological aspects of the degraded soil is the amendment with low contaminated and stabilized industrial organic sludge. The content of nutrients P and N, together with stabilized organic matter, makes this material an excellent fertilizer and soil conditioner, fostering biota colonization and succession in the degraded site. However, choice of native plant species to restore a degraded site must be guided by some minimal criteria, such as plant survival/adaptation and plant biomass productivity. Thus, in this 3-month study under environmental conditions, phytoproductivity tests with five native plant species (Surinam cherry Eugenia uniflora L., C. myrianthum-Citharexylum myrianthum, Inga-Inga spp., Brazilian peppertree Schinus terebinthifolius, and Sour cherry Prunus cerasus) were performed to assess these criteria, and additional biochemical parameters were measured in plant tissues (i.e., protein content and peroxidase activity) exposed to different soil/sludge mixture proportions. The results show that three native plants were more adequate to restore vegetation on degraded sites: Surinam cherry, C. myrianthum, and Brazilian peppertree. Thus, this study demonstrates that phytoproductivity tests associated with biochemical endpoint measurements can help in the choice of native plant species, as well as aiding in the choice of the most appropriate soil/stabilized sludge proportion in order to optimize biomass production.

Degradation of biodegradable plastic mulch films in soil environment by phylloplane fungi isolated from gramineous plants.

PubMed

Koitabashi, Motoo; Noguchi, Masako T; Sameshima-Yamashita, Yuka; Hiradate, Syuntaro; Suzuki, Ken; Yoshida, Shigenobu; Watanabe, Takashi; Shinozaki, Yukiko; Tsushima, Seiya; Kitamoto, Hiroko K

2012-08-02

To improve the biodegradation of biodegradable plastic (BP) mulch films, 1227 fungal strains were isolated from plant surface (phylloplane) and evaluated for BP-degrading ability. Among them, B47-9 a strain isolated from the leaf surface of barley showed the strongest ability to degrade poly-(butylene succinate-co-butylene adipate) (PBSA) and poly-(butylene succinate) (PBS) films. The strain grew on the surface of soil-mounted BP films, produced breaks along the direction of hyphal growth indicated that it secreted a BP-degrading enzyme, and has directly contributing to accelerating the degradation of film. Treatment with the culture filtrate decomposed 91.2 wt%, 23.7 wt%, and 14.6 wt% of PBSA, PBS, and commercially available BP polymer blended mulch film, respectively, on unsterlized soil within 6 days. The PCR-DGGE analysis of the transition of soil microbial community during film degradation revealed that the process was accompanied with drastic changes in the population of soil fungi and Acantamoeba spp., as well as the growth of inoculated strain B47-9. It has a potential for application in the development of an effective method for accelerating degradation of used plastics under actual field conditions.

Tree planting - strip-mined area in Maryland

Treesearch

Fred L. Bagley

1980-01-01

This report is written to elucidate some of the problems encountered in the planting of trees on strip-mined areas in Maryland. When problems are recognized, normally a solution (or at least, an improvement) can be instituted to alleviate the problem. The methods cited herein are those of experienced foresters engaged in strip-mine planting during the past seventeen...

Functional Analysis of the Glucan Degradation Locus in Caldicellulosiruptor bescii Reveals Essential Roles of Component Glycoside Hydrolases in Plant Biomass Deconstruction

PubMed Central

Conway, Jonathan M.; McKinley, Bennett S.; Seals, Nathaniel L.; Hernandez, Diana; Khatibi, Piyum A.; Poudel, Suresh; Giannone, Richard J.; Hettich, Robert L.; Williams-Rhaesa, Amanda M.; Lipscomb, Gina L.; Adams, Michael W. W.

2017-01-01

ABSTRACT The ability to hydrolyze microcrystalline cellulose is an uncommon feature in the microbial world, but it can be exploited for conversion of lignocellulosic feedstocks into biobased fuels and chemicals. Understanding the physiological and biochemical mechanisms by which microorganisms deconstruct cellulosic material is key to achieving this objective. The glucan degradation locus (GDL) in the genomes of extremely thermophilic Caldicellulosiruptor species encodes polysaccharide lyases (PLs), unique cellulose binding proteins (tāpirins), and putative posttranslational modifying enzymes, in addition to multidomain, multifunctional glycoside hydrolases (GHs), thereby representing an alternative paradigm for plant biomass degradation compared to fungal or cellulosomal systems. To examine the individual and collective in vivo roles of the glycolytic enzymes, the six GH genes in the GDL of Caldicellulosiruptor bescii were systematically deleted, and the extents to which the resulting mutant strains could solubilize microcrystalline cellulose (Avicel) and plant biomass (switchgrass or poplar) were examined. Three of the GDL enzymes, Athe_1867 (CelA) (GH9-CBM3-CBM3-CBM3-GH48), Athe_1859 (GH5-CBM3-CBM3-GH44), and Athe_1857 (GH10-CBM3-CBM3-GH48), acted synergistically in vivo and accounted for 92% of naked microcrystalline cellulose (Avicel) degradation. However, the relative importance of the GDL GHs varied for the plant biomass substrates tested. Furthermore, mixed cultures of mutant strains showed that switchgrass solubilization depended on the secretome-bound enzymes collectively produced by the culture, not on the specific strain from which they came. These results demonstrate that certain GDL GHs are primarily responsible for the degradation of microcrystalline cellulose-containing substrates by C. bescii and provide new insights into the workings of a novel microbial mechanism for lignocellulose utilization. IMPORTANCE The efficient and extensive degradation

Plant uptake of explosives from contaminated soil at the Joliet Army Ammunition Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zellmer, S.D.; Schneider, J.F.; Tomczyk, N.A.

1995-04-01

Explosives and their degradation products may enter the animal and human food chains through plants grown on soils contaminated with explosives. Soil and plant samples were collected from the Group 61 area at the Joliet Army Ammunition Plant and analyzed to determine the extent to which 2,4,6-trinitrotoluene (TNT) and its degradation products are taken up by existing vegetation and crops growing on contaminated soils. Neither TNT nor its degradation products was detected in any of the aboveground plant organs of existing vegetation. Oat (Avena sativa L.) and perennial ryegrass (Lolium perenne L.) were planted on TNT-contaminated soils amended with threemore » levels of chopped grass hay. Extractable TNT concentrations in hay-amended soils were monitored for almost 1 year. Crop establishment and growth improved with increased levels of hay amendment, but TNT uptake was not affected or detected in any aboveground crop organs. Evidence was found to indicate that soil manipulation and hay addition may reduce extractable TNT concentration in soils, but the wide variations in TNT concentrations in these soils prevented development of conclusive evidence regarding reduction of extractable TNT concentrations. Results from this study suggest that vegetation grown on TNT-contaminated soils is not a major health concern because TNT and its degradation products were not detected in aboveground plant organs. However, low concentrations of TNT, 4-amino-2,6-dinitrotoluene, and 2-amino-4,6-dinitrotoluene were detected in or on some existing vegetation and crop roots. 21 refs., 10 figs., 26 tabs.« less

Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants.

PubMed

Aylward, Frank O; Khadempour, Lily; Tremmel, Daniel M; McDonald, Bradon R; Nicora, Carrie D; Wu, Si; Moore, Ronald J; Orton, Daniel J; Monroe, Matthew E; Piehowski, Paul D; Purvine, Samuel O; Smith, Richard D; Lipton, Mary S; Burnum-Johnson, Kristin E; Currie, Cameron R

2015-01-01

Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.

Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants

PubMed Central

Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel M.; McDonald, Bradon R.; Nicora, Carrie D.; Wu, Si; Moore, Ronald J.; Orton, Daniel J.; Monroe, Matthew E.; Piehowski, Paul D.; Purvine, Samuel O.; Smith, Richard D.; Lipton, Mary S.; Burnum-Johnson, Kristin E.; Currie, Cameron R.

2015-01-01

Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass. PMID:26317212

Repression of Pseudomonas putida phenanthrene-degrading activity by plant root extracts and exudates.

PubMed

Rentz, Jeremy A; Alvarez, Pedro J J; Schnoor, Jerald L

2004-06-01

The phenanthrene-degrading activity (PDA) of Pseudomonas putida ATCC 17484 was repressed after incubation with plant root extracts of oat (Avena sativa), osage orange (Maclura pomifera), hybrid willow (Salix alba x matsudana), kou (Cordia subcordata) and milo (Thespesia populnea) and plant root exudates of oat (Avena sativa) and hybrid poplar (Populus deltoides x nigra DN34). Total organic carbon content of root extracts ranged from 103 to 395 mg l(-1). Characterization of root extracts identified acetate (not detectable to 8.0 mg l(-1)), amino acids (1.7-17.3 mg l(-1)) and glucose (1.6-14.0 mg l(-1)), indicating a complex mixture of substrates. Repression was also observed after exposure to potential root-derived substrates, including organic acids, glucose (carbohydrate) and glutamate (amino acid). Carbon source regulation (e.g. catabolite repression) was apparently responsible for the observed repression of P. putida PDA by root extracts. However, we showed that P. putida grows on root extracts and exudates as sole carbon and energy sources. Enhanced growth on root products may compensate for partial repression, because larger microbial populations are conducive to faster degradation rates. This would explain the commonly reported increase in phenanthrene removal in the rhizosphere.

Soil Quality of Bauxite Mining Areas

NASA Astrophysics Data System (ADS)

Terezinha Gonçalves Bizuti, Denise; Dinarowski, Marcela; Casagrande, José Carlos; Silva, Luiz Gabriel; Soares, Marcio Roberto; Henrique Santin Brancalion, Pedro

2015-04-01

The study on soil quality index (SQI) aims to assess the current state of the soil after use and estimating its recovery through sustainable management practices This type of study is being used in this work in order to check the efficiency of forest recovery techniques in areas that have been deeply degraded by bauxite mining process, and compare them with the area of native forest, through the determination of SQI. Treatments were newly mined areas, areas undergoing restoration (topsoil use with planting of native forest species), areas in rehabilitation (employment of the green carpet with topsoil and planting of native forest species) and areas of native forests, with six repetitions, in areas of ALCOA, in the municipality of Poços de Caldas/MG. To this end, we used the additive pondered model, establishing three functions: Fertility, water movement and root development, based on chemical parameters (organic matter, base saturation, aluminum saturation and calcium content); physical (macroporosity, soil density and clay content); and microbiological testing (basal respiration by the emission of CO2 ). The SQIs obtained for each treatment was 41%, 56%, 63% and 71% for newly mined areas, native forest, areas in restoration and rehabilitation, respectively. The recovering technique that most approximates the degraded soil to the soil of reference is the restoration, where there was no statistically significant difference of areas restored with native forest. It was found that for the comparison of the studied areas must take into account the nutrient cycling, that disappear with plant removal in mining areas, once the soil of native forest features low fertility and high saturation by aluminum, also taking in account recovering time.

Effects of Warming on Chlorophyll Degradation and Carbohydrate Accumulation of Alpine Herbaceous Species during Plant Senescence on the Tibetan Plateau

PubMed Central

Shi, Changguang; Sun, Geng; Zhang, Hongxuan; Xiao, Bingxue; Ze, Bai; Zhang, Nannan; Wu, Ning

2014-01-01

Plant senescence is a critical life history process accompanied by chlorophyll degradation and has large implications for nutrient resorption and carbohydrate storage. Although photoperiod governs much of seasonal leaf senescence in many plant species, temperature has also been shown to modulate this process. Therefore, we hypothesized that climate warming would significantly impact the length of the plant growing season and ultimate productivity. To test this assumption, we measured the effects of simulated autumn climate warming paradigms on four native herbaceous species that represent distinct life forms of alpine meadow plants on the Tibetan Plateau. Conditions were simulated in open-top chambers (OTCs) and the effects on the degradation of chlorophyll, nitrogen (N) concentration in leaves and culms, total non-structural carbohydrate (TNC) in roots, growth and phenology were assessed during one year following treatment. The results showed that climate warming in autumn changed the senescence process only for perennials by slowing chlorophyll degradation at the beginning of senescence and accelerating it in the following phases. Warming also increased root TNC storage as a result of higher N concentrations retained in leaves; however, this effect was species dependent and did not alter the growing and flowering phenology in the following seasons. Our results indicated that autumn warming increases carbohydrate accumulation, not only by enhancing activities of photosynthetic enzymes (a mechanism proposed in previous studies), but also by affecting chlorophyll degradation and preferential allocation of resources to different plant compartments. The different responses to warming can be explained by inherently different growth and phenology patterns observed among the studied species. The results implied that warming leads to changes in the competitive balance among life forms, an effect that can subsequently shift vegetation distribution and species composition

Materials Degradation and Detection (MD2): Deep Dive Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCloy, John S.; Montgomery, Robert O.; Ramuhalli, Pradeep

2013-02-01

An effort is underway at Pacific Northwest National Laboratory (PNNL) to develop a fundamental and general framework to foster the science and technology needed to support real-time monitoring of early degradation in materials used in the production of nuclear power. The development of such a capability would represent a timely solution to the mounting issues operators face with materials degradation in nuclear power plants. The envisioned framework consists of three primary and interconnected “thrust” areas including 1) microstructural science, 2) behavior assessment, and 3) monitoring and predictive capabilities. A brief state-of-the-art assessment for each of these core technology areas ismore » discussed in the paper.« less

Red List of vascular plants of the Wadden Sea Area

NASA Astrophysics Data System (ADS)

Wind, P.; van der Ende, M.; Garve, E.; Schacherer, A.; Thissen, J. B. M.

1996-10-01

In the Wadden Sea area, a total of 248 (sub)species of vascular plants are threatened in at least one subregion. Of these, 216 (sub)species are threatened in the entire area and are therefore placed on the trialteral Red List. 17 (sub)species of the listed vascular plants are (probably) extinct in the entire Wadden Sea area. The status of 47 (sub)species of vascular plants is (probably) critical; 61 (sub)species are (probably) endangered; the status of 65 (sub)species is (probably) vulnerable and that of 26 (sub)species susceptible.

Nitrogen-fixing legume tree species for the reclamation of severely degraded lands in Brazil.

PubMed

Chaer, Guilherme Montandon; Resende, Alexander Silva; Campello, Eduardo Francia Carneiro; de Faria, Sergio Miana; Boddey, Robert Michael

2011-02-01

The main challenges faced in the reclamation of severely degraded lands are in the management of the systems and finding plant species that will grow under the harsh conditions common in degraded soils. This is especially important in extremely adverse situations found in some substrates from mining activities or soils that have lost their upper horizons. Under these conditions, recolonization of the area by native vegetation through natural succession processes may be extremely limited. Once the main physical and chemical factors restrictive to plant growth are corrected or attenuated, the introduction of leguminous trees able to form symbioses with nodulating N₂-fixing bacteria and arbuscular mycorrhizal fungi constitutes an efficient strategy to accelerate soil reclamation and initiate natural succession. These symbioses give the legume species a superior capacity to grow quickly in poor substrates and to withstand the harsh conditions presented in degraded soils. In this article we describe several successful results in Brazil using N₂-fixing legume tree species for reclamation of areas degraded by soil erosion, construction and mining activities, emphasizing the potential of the technique to recover soil organic matter levels and restore ecosystem biodiversity and other environmental functions.

Effect of high surface area activated carbon on thermal degradation of jet fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gergova, K.; Eser, S.; Arumugam, R.

1995-05-01

Different solid carbons added to jet fuel during thermal stressing cause substantial changes in pyrolytic degradation reactions. Activated carbons, especially high surface area activated carbons were found to be very effective in suppressing solid deposition on metal reactor walls during stressing at high temperatures (425 and 450{degrees}C). The high surface area activated carbon PX-21 prevented solid deposition on reactor walls even after 5h at 450{degrees}C. The differences seen in the liquid product composition when activated carbon is added indicated that the carbon surfaces affect the degradation reactions. Thermal stressing experiments were carried out on commercial petroleum-derived JPTS jet fuel. Wemore » also used n-octane and n-dodecane as model compounds in order to simplify the study of the chemical changes which take place upon activated carbon addition. In separate experiments, the presence of a hydrogen donor, decalin, together with PX-21 was also studied.« less

Development of novel assays for lignin degradation: comparative analysis of bacterial and fungal lignin degraders.

PubMed

Ahmad, Mark; Taylor, Charles R; Pink, David; Burton, Kerry; Eastwood, Daniel; Bending, Gary D; Bugg, Timothy D H

2010-05-01

Two spectrophotometric assays have been developed to monitor breakdown of the lignin component of plant lignocellulose: a continuous fluorescent assay involving fluorescently modified lignin, and a UV-vis assay involving chemically nitrated lignin. These assays have been used to analyse lignin degradation activity in bacterial and fungal lignin degraders, and to identify additional soil bacteria that show activity for lignin degradation. Two soil bacteria known to act as aromatic degraders, Pseudomonas putida and Rhodococcus sp. RHA1, consistently showed activity in these assays, and these strains were shown in a small scale experiment to breakdown lignocellulose, producing a number of monocyclic phenolic products. Using milled wood lignin prepared from wheat straw, pine, and miscanthus, some bacterial lignin degraders were found to show specificity for lignin type. These assays could be used to identify novel lignin degraders for breakdown of plant lignocellulose.

Investigation of relationships between removals of tetracycline and degradation products and physicochemical parameters in municipal wastewater treatment plant.

PubMed

Topal, Murat; Uslu Şenel, Gülşad; Öbek, Erdal; Arslan Topal, E Işıl

2016-05-15

Determination of the effect of physicochemical parameters on the removal of tetracycline (TC) and degradation products is important because of the importance of the removal of antibiotics in Wastewater Treatment Plant (WWTP). Therefore, the purpose of this study was to investigate the relationships between removals of TC and degradation products and physicochemical parameters in Municipal Wastewater Treatment Plant (MWWTP). For this aim, (i) the removals of physicochemical parameters in a MWWTP located in Elazığ city (Turkey) were determined (ii) the removals of TC and degradation products in MWWTP were determined (iii) the relationships between removals of TC and degradation products and physicochemical parameters were investigated. TC, 4-epitetracycline (ETC), 4-epianhydrotetracycline (EATC), anhydrotetracycline (ATC), and physicochemical parameters (pH, temperature, electrical conductivity (EC), suspended solids (SS), BOD5, COD, total organic carbon (TOC), NH4(+)-N, NO2(-)-N, NO3(-)-N and O-PO4(-3)) were determined. The calculation of the correlation coefficients of relationships between the physicochemical parameters and TC, EATC, ATC showed that, among the investigated parameters, EATC and SS most correlated. The removals of other physicochemical parameters were not correlated with TC, EATC and ATC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role of proteolytic enzymes in degradation of plant tissues. Summary of results of studies completed on the prior

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewosz, J.; Kelman, A.; Sequeira, L.

1991-12-31

Strain SR 394 of Erwinia carotovora (Ecc) produced proteases constitutively in all media tested. Growth of Ecc and production of protease were enhanced significantly by the presence of poetic materials and/or plant call walls in the test media. After electrofocusing, one major and one minor protease bands, at PI 4.8 and PI 5.1, respectively, were detected. Only one band of 43 kDa was detected on SDS gels. Only one protease band was detected in SDS gels of infected plant extracts. This protease was purified to homogeneity. It in a highly thermostable metal protease; it degrades gelatin, soluble collagen and hidemore » powderazure, shows weak activity on casein and azocasein, but does not degrade insoluble collagen or elastin.« less

Sono-photo-degradation of carbamazepine in a thin falling film reactor: Operation costs in pilot plant.

PubMed

Expósito, A J; Patterson, D A; Monteagudo, J M; Durán, A

2017-01-01

The photo-Fenton degradation of carbamazepine (CBZ) assisted with ultrasound radiation (US/UV/H 2 O 2 /Fe) was tested in a lab thin film reactor allowing high TOC removals (89% in 35min). The synergism between the UV process and the sonolytic one was quantified as 55.2%. To test the applicability of this reactor for industrial purposes, the sono-photo-degradation of CBZ was also tested in a thin film pilot plant reactor and compared with a 28L UV-C conventional pilot plant and with a solar Collector Parabolic Compound (CPC). At a pilot plant scale, a US/UV/H 2 O 2 /Fe process reaching 60% of mineralization would cost 2.1 and 3.8€/m 3 for the conventional and thin film plant respectively. The use of ultrasound (US) produces an extra generation of hydroxyl radicals, thus increasing the mineralization rate. In the solar process, electric consumption accounts for a maximum of 33% of total costs. Thus, for a TOC removal of 80%, the cost of this treatment is about 1.36€/m 3 . However, the efficiency of the solar installation decreases in cloudy days and cannot be used during night, so that a limited flow rate can be treated. Copyright © 2016 Elsevier B.V. All rights reserved.

Regeneration of a keystone semiarid shrub over its range in Spain: habitat degradation overrides the positive effects of plant-animal mutualisms.

PubMed

Rey, Pedro J; Cancio, Inmaculada; Manzaneda, Antonio J; González-Robles, Ana; Valera, Francisco; Salido, Teresa; Alcántara, Julio M

2018-06-22

Global change drivers are currently affecting semiarid ecosystems. Because these ecosystems differ from others in biotic and abiotic filters, cues for plant regeneration and management derived from elsewhere may not be applicable to semiarid ecosystems. We sought to determine the extent to which regional variation in regeneration prospects of a long-lived semiarid keystone shrub depends on anthropogenic habitat degradation, plant-animal interactions and climate determinants. We investigated the regeneration ability (via population size structure, juvenile density and juvenile/adult ratio), fruit set and seed dispersal of Ziziphus lotus in 25 localities spanning the range of its threatened habitats in Spain. We dissected the relative contribution of different regeneration determinants using multiple regression and structural equation modelling. Population regeneration was extremely poor, and size structures were biased towards large classes and low juvenile densities and juvenile/adult ratios. Poor regeneration was often coincident with seed dispersal collapse. However, the positive effect of seed dispersal on population regeneration disappeared after considering its relationship with habitat degradation. Protected areas did have juveniles. Together, these data suggest that habitat degradation directly impacts juvenile establishment. Our results provide insights into habitat and species management at the regional level. Z. lotus populations are currently driven by persistence-based dynamics through the longevity of the species. Nonetheless, collapsed seed dispersal, poor regeneration and the removal of adults from their habitats forecast extinction of Z. lotus in many remnants. The extreme longevity of Z. lotus grants opportunities for the recovery of its populations and habitats through effective enforcement of regulations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Modeling the effect of terraces on land degradation in tropical upland agricultural area

NASA Astrophysics Data System (ADS)

Christanto, N.; Shrestha, D. P.; Jetten, V. G.; Setiawan, A.

2012-04-01

Java, the most populated Island in Indonesia, in the pas view decades suffer land degradation do to extreme weather, population pressure and landuse/cover change. The study area, Serayu sub-catchment, as part of Serayu catchment is one of the representative example of Indonesia region facing land use change and land degradation problem. The study attempted to simulate the effect of terraces on land degradation (Soil erosion and landslide hazard) in Serayu sub-catchment using deterministic modeling by means of PCRaster® simulation. The effect of the terraces on tropical upland agricultural area is less studied. This paper will discuss about the effect of terraces on land degradation assessment. Detail Dem is extremely difficult to obtain in developing country like Indonesia. Therefore, an artificial DEM which give an impression of the terraces was built. Topographical maps, Ikonos Image and average of height distribution based on field measurement were used to build the artificial DEM. The result is used in STARWARS model as an input. In combine with Erosion model and PROBSTAB, soil erosion and landslide hazard were quantified. The models were run in two different environment based on the: 1) normal DEM 2.) Artificial DEM (with terraces impression). The result is compared. The result shows that the models run in an artificial DEM give a significant increase on the probability of failure by 20.5%. In the other hand, the erosion rate has fall by 11.32% as compared to the normal DEM. The result of hydrological sensitivity analysis shows that soil depth was the most sensitive parameter. For the slope stability modeling, the most sensitive parameter was slope followed by friction angle and cohesion. The erosion modeling, the model was sensitive to the vegetation cover, soil erodibility followed by BD and KSat. Model validations were applied to assess the accuracy of the models. However, the results of dynamic modeling are ideal for land degradation assessment. Dynamic

Role of anaerobic fungi in wheat straw degradation and effects of plant feed additives on rumen fermentation parameters in vitro.

PubMed

Dagar, S S; Singh, N; Goel, N; Kumar, S; Puniya, A K

2015-01-01

In the present study, rumen microbial groups, i.e. total rumen microbes (TRM), total anaerobic fungi (TAF), avicel enriched bacteria (AEB) and neutral detergent fibre enriched bacteria (NEB) were evaluated for wheat straw (WS) degradability and different fermentation parameters in vitro. Highest WS degradation was shown for TRM, followed by TAF, NEB and least by AEB. Similar patterns were observed with total gas production and short chain fatty acid profiles. Overall, TAF emerged as the most potent individual microbial group. In order to enhance the fibrolytic and rumen fermentation potential of TAF, we evaluated 18 plant feed additives in vitro. Among these, six plant additives namely Albizia lebbeck, Alstonia scholaris, Bacopa monnieri, Lawsonia inermis, Psidium guajava and Terminalia arjuna considerably improved WS degradation by TAF. Further evaluation showed A. lebbeck as best feed additive. The study revealed that TAF plays a significant role in WS degradation and their fibrolytic activities can be improved by inclusion of A. lebbeck in fermentation medium. Further studies are warranted to elucidate its active constituents, effect on fungal population and in vivo potential in animal system.

Delayed degradation in soil of foliar herbicides glyphosate and sulcotrione previously absorbed by plants: consequences on herbicide fate and risk assessment.

PubMed

Doublet, Jérémy; Mamy, Laure; Barriuso, Enrique

2009-10-01

Following application, pesticides can be intercepted and absorbed by weeds and/or crops. Plants containing pesticides residues may then reach the soil during the crop cycle or after harvest. However, the fate in soil of pesticides residues in plants is unknown. Two commonly used foliar herbicides, glyphosate and sulcotrione, (14)C-labeled, were applied on leaves of oilseed rape and/or maize, translocation was studied, and then soil incubations of aerial parts of plants containing herbicides residues were performed. Soil treated directly with herbicides was used as control. The effects of adjuvants on herbicide plant-absorption and subsequent soil-degradation were also investigated comparing herbicides application as active ingredients and as commercial formulations. The fate in soil of herbicides residues in plants was different from that of control, and different for glyphosate and sulcotrione. Mineralization in soil of glyphosate in crops decreased compared to control, and amounts of (14)C-extractable residues, mainly composed by the metabolite aminomethylphosphonic acid (AMPA), and non-extractable residues (NER) increased. In contrast, mineralization in soil of sulcotrione in maize increased compared to control, with a decrease in the (14)C-extractable residues and an increase in NER. The fate of both herbicides was influenced by the type of plant organ in which herbicide was incorporated, because of differences in herbicides bioavailability and organs biodegradability, but not by adjuvants. Absorption of both herbicides in plant delays their subsequent soil-degradation, and particularly, glyphosate persistence in soil could increase from two to six times. The modifications of herbicide degradation in soil due to interception by plants should be considered for environmental risks assessment.

Heterologous Expression of Plant Cell Wall Degrading Enzymes for Effective Production of Cellulosic Biofuels

PubMed Central

Jung, Sang-Kyu; Parisutham, Vinuselvi; Jeong, Seong Hun; Lee, Sung Kuk

2012-01-01

A major technical challenge in the cost-effective production of cellulosic biofuel is the need to lower the cost of plant cell wall degrading enzymes (PCDE), which is required for the production of sugars from biomass. Several competitive, low-cost technologies have been developed to produce PCDE in different host organisms such as Escherichia coli, Zymomonas mobilis, and plant. Selection of an ideal host organism is very important, because each host organism has its own unique features. Synthetic biology-aided tools enable heterologous expression of PCDE in recombinant E. coli or Z. mobilis and allow successful consolidated bioprocessing (CBP) in these microorganisms. In-planta expression provides an opportunity to simplify the process of enzyme production and plant biomass processing and leads to self-deconstruction of plant cell walls. Although the future of currently available technologies is difficult to predict, a complete and viable platform will most likely be available through the integration of the existing approaches with the development of breakthrough technologies. PMID:22911272

Degradation of biodegradable plastic mulch films in soil environment by phylloplane fungi isolated from gramineous plants

PubMed Central

2012-01-01

To improve the biodegradation of biodegradable plastic (BP) mulch films, 1227 fungal strains were isolated from plant surface (phylloplane) and evaluated for BP-degrading ability. Among them, B47-9 a strain isolated from the leaf surface of barley showed the strongest ability to degrade poly-(butylene succinate-co-butylene adipate) (PBSA) and poly-(butylene succinate) (PBS) films. The strain grew on the surface of soil-mounted BP films, produced breaks along the direction of hyphal growth indicated that it secreted a BP-degrading enzyme, and has directly contributing to accelerating the degradation of film. Treatment with the culture filtrate decomposed 91.2 wt%, 23.7 wt%, and 14.6 wt% of PBSA, PBS, and commercially available BP polymer blended mulch film, respectively, on unsterlized soil within 6 days. The PCR-DGGE analysis of the transition of soil microbial community during film degradation revealed that the process was accompanied with drastic changes in the population of soil fungi and Acantamoeba spp., as well as the growth of inoculated strain B47-9. It has a potential for application in the development of an effective method for accelerating degradation of used plastics under actual field conditions. PMID:22856640

Biodegradation of Mixed PAHs by PAH-Degrading Endophytic Bacteria.

PubMed

Zhu, Xuezhu; Ni, Xue; Waigi, Michael Gatheru; Liu, Juan; Sun, Kai; Gao, Yanzheng

2016-08-09

Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs) in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P₁ (Stenotrophomonas sp.) and P₃ (Pseudomonas sp.), which degraded more than 90% of phenanthrene (PHE) within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP), PHE, fluorene (FLR), pyrene (PYR), and benzo(a)pyrene (B(a)P) as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P₁ degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(a)P, and strain P₃ degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(a)P. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days). Compared with strain P₁, strain P₃ has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.

Traits of Heracleum sosnowskyi Plants in Monostand on Invaded Area

PubMed Central

2015-01-01

The ability of giant hogweeds to form monodominant communities and even pure monostands in invaded areas has been well documented. Understanding of the mechanisms leading to monostand formation can aid in determining the limitations of existing community ecology models and establishing an effective management plan for invasive species elimination. The aim of this observational study was to investigate traits of Heracleum sosnowskyi plants (demography, canopy structure, morphology and physiology) of the plants in a pure stand in an invaded area useful for understanding potential monostand formation mechanisms. All measurements were performed in one typical Heracleum sosnowskyi monostand located in an abandoned agriculture field located in Syktyvkar city suburb (North-east Russia). This monostand consisted of five main plant growth stages: seed, seedling, juvenile, vegetative adult, and generative adult. Plants of all stages began to grow simultaneously shortly after the snowmelt, at the same time as spring ephemeral plant species grew. The density of generative plants did not change during the vegetation period, but the density of the other plant stages rapidly decreased after the formation of a tall (up to 2–2.5 m) and dense (Leaf area index up to 6.5) canopy. The canopy captured approximately 97% of the light. H. sosnowskyi showed high (several orders of magnitude higher than average taiga zone grasses) photosynthetic water use efficiency (6–7 μM CO2/μM H2O). Formation of H. sosnowskyi monostands occurs primarily in disturbed areas with relatively rich and well-moistened soils. Early commencement of growth, rapid formation of a dense canopy, high efficiency of light and water use during photosynthesis, ability of young plants to survive in low light conditions, rapid recovery of above-ground plant parts after damage, and the high density of the soil seed bank are the most important traits of H. sosnowskyi plants for monostand formation in invaded areas. PMID

Potential for plant growth promotion by a consortium of stress-tolerant 2,4-dinitrotoluene-degrading bacteria: isolation and characterization of a military soil.

PubMed

Thijs, Sofie; Weyens, Nele; Sillen, Wouter; Gkorezis, Panagiotis; Carleer, Robert; Vangronsveld, Jaco

2014-07-01

The presence of explosives in soils and the interaction with drought stress and nutrient limitation are among the environmental factors that severely affect plant growth on military soils. In this study, we seek to isolate and identify the cultivable bacteria of a 2,4-dinitrotoluene (DNT) contaminated soil (DS) and an adjacent grassland soil (GS) of a military training area aiming to isolate new plant growth-promoting (PGP) and 2,4-DNT-degrading strains. Metabolic profiling revealed disturbances in Ecocarbon use in the bare DS; isolation of cultivable strains revealed a lower colony-forming-unit count and a less diverse community associated with DS in comparison with GS. New 2,4-DNT-tolerant strains were identified by selective enrichments, which were further characterized by auxanography for 2,4-DNT use, resistance to drought stress, cold, nutrient starvation and PGP features. By selecting multiple beneficial PGP and abiotic stress-resistant strains, efficient 2,4-DNT-degrading consortia were composed. After inoculation, consortium UHasselt Sofie 3 with seven members belonging to Burkholderia, Variovorax, Bacillus, Pseudomonas and Ralstonia species was capable to successfully enhance root length of Arabidopsis under 2,4-DNT stress. After 9 days, doubling of main root length was observed. Our results indicate that beneficial bacteria inhabiting a disturbed environment have the potential to improve plant growth and alleviate 2,4-DNT stress. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Estrogen Degraders and Estrogen Degradation Pathway Identified in an Activated Sludge.

PubMed

Chen, Yi-Lung; Fu, Han-Yi; Lee, Tzong-Huei; Shih, Chao-Jen; Huang, Lina; Wang, Yu-Sheng; Ismail, Wael; Chiang, Yin-Ru

2018-05-15

The environmental release and fate of estrogens are becoming an increasing public concern. Bacterial degradation has been considered the main process for eliminating estrogens from wastewater treatment plants. Various bacterial isolates are reportedly capable of aerobic estrogen degradation, and several estrogen degradation pathways have been proposed in proteobacteria and actinobacteria. However, the ecophysiological relevance of estrogen-degrading bacteria in the environment is unclear. In this study, we investigated the estrogen degradation pathway and corresponding degraders in activated sludge collected from the Dihua Sewage Treatment Plant, Taipei, Taiwan. Cultivation-dependent and cultivation-independent methods were used to assess estrogen biodegradation in the collected activated sludge. Estrogen metabolite profile analysis revealed the production of pyridinestrone acid and two A/B-ring cleavage products in activated sludge incubated with estrone (1 mM), which are characteristic of the 4,5- seco pathway. PCR-based functional assays detected sequences closely related to alphaproteobacterial oecC , a key gene of the 4,5- seco pathway. Metagenomic analysis suggested that Novosphingobium spp. are major estrogen degraders in estrone-amended activated sludge. Novosphingobium sp. strain SLCC, an estrone-degrading alphaproteobacterium, was isolated from the examined activated sludge. The general physiology and metabolism of this strain were characterized. Pyridinestrone acid and the A/B-ring cleavage products were detected in estrone-grown strain SLCC cultures. The production of pyridinestrone acid was also observed during the aerobic incubation of strain SLCC with 3.7 nM (1 μg/liter) estrone. This concentration is close to that detected in many natural and engineered aquatic ecosystems. The presented data suggest the ecophysiological relevance of Novosphingobium spp. in activated sludge. IMPORTANCE Estrogens, which persistently contaminate surface water

Relationship soil-water-plant after the dry season in dry Mediterranean areas

NASA Astrophysics Data System (ADS)

Hueso-González, P.; Jiménez-Donaire, V.; Ruiz-Sinoga, J. D.

2012-04-01

Preliminary studies have determined the existence of a pluviometric gradient around Mediterranean system, which varies from 240 to 1 100 mm mean annual rainfall. This gradient has an incidence in the physical, chemical and hydrological properties in soils with the same litology. Empiric results conclude that humid eco-geomorphological systems are controlled by biotic processes, whereas in arid eco-geomorphological systems, are abiotic factors which have more importance in soil degradation processes. The study area of the present work is located in Málaga (Andalusia, Spain), in the southern part of the Natural Park "Sierra Tejeda, Almijara y Alhama". There, the mean annual temperature is around 18 °C and the mean rainfall is 650 mm. Predominant vegetation corresponds to the termomediterranean serie Smilaci Mauritanicae-Querceto Rotundifoliae Sigmetum, typical of basic soils. The aim of this study is to analyse the immediate hydrological response of the soil under different vegetation covers, through the analysis of certain properties, all this, under subhumid ombrotipe. A random choice of ten representative plants has been done. These plants, with different sizes, were located in the same Southern slope. The soil samples were taken right beside the plant log, and also within a distance of 0.4 to 1 metre from them, depending on the plant size. The sampling was carried out between the end of the dry season and the beginning of the wet one, after a 20% of the mean annual rainfall had rained. The physical, chemical and hydrological analyzes -both in the field and the laboratory- were: exchange-base, total carbon, cation exchange capacity, soil infiltration capacity, salt content, hydrophobia, organic matter, soil organic carbon, total nitrogen, wetting profile in bared soil, wetting profile under vegetation cover (shrubland), and p.H. Literature reveals that rainfall affects significantly the edafogenetic factors, regarding the pluviometric gradient level. In the

Functional analysis of the Glucan Degradation Locus (GDL) in Caldicellulosiruptor bescii reveals essential roles of component glycoside hydrolases in plant biomass deconstruction.

PubMed

Conway, Jonathan M; McKinley, Bennett S; Seals, Nathaniel L; Hernandez, Diana; Khatibi, Piyum A; Poudel, Suresh; Giannone, Richard J; Hettich, Robert L; Williams-Rhaesa, Amanda M; Lipscomb, Gina L; Adams, Michael W W; Kelly, Robert M

2017-10-06

The ability to hydrolyze microcrystalline cellulose is an uncommon feature in the microbial world, but one that can be exploited for conversion of lignocellulosic feedstocks into bio-based fuels and chemicals. Understanding the physiological and biochemical mechanisms by which microorganisms deconstruct cellulosic material is key to achieving this objective. The Glucan Degradation Locus (GDL) in the genomes of extremely thermophilic Caldicellulosiruptor species encodes polysaccharide lyases (PLs), unique cellulose binding proteins (tāpirins), and putative post-translational modifying enzymes, in addition to multi-domain, multi-functional glycoside hydrolases (GHs), thereby representing an alternative paradigm for plant biomass degradation, as compared to fungal or cellulosomal systems. To examine the individual and collective in vivo roles of the glycolytic enzymes, the six GHs in the GDL of Caldicellulosiruptor bescii were systematically deleted, and the extent to which the resulting mutant strains could solubilize microcrystalline cellulose (Avicel) and plant biomasses (switchgrass or poplar) was examined. Three of the GDL enzymes, Athe_1867 (CelA) (GH9-CBM3-CBM3-CBM3-GH48), Athe_1859 (GH5-CBM3-CBM3-GH44), and Athe_1857 (GH10-CBM3-CBM3-GH48), acted synergistically in vivo and accounted for 92% of naked microcellulose (Avicel) degradation. However, the relative importance of the GDL GHs varied for the plant biomass substrates tested. Furthermore, mixed cultures of mutant strains showed switchgrass solubilization depended on the secretome-bound enzymes collectively produced by the culture and not on the specific strain from which they came. These results demonstrate that certain GDL GHs are primarily responsible for the degradation of microcrystalline-containing substrates by C. bescii and provide new insights into the workings of a novel microbial mechanism for lignocellulose utilization. Importance The efficient and extensive degradation of complex

Determination of fluorotelomer alcohols and their degradation products in biosolids-amended soils and plants using ultra-high performance liquid chromatography tandem mass spectrometry.

PubMed

Zhang, Hongna; Wen, Bei; Hu, Xiaoyu; Wu, Yali; Luo, Lei; Chen, Zien; Zhang, Shuzhen

2015-07-24

Degradation of fluorotelomer alcohols (FTOHs) was recognized as an additional source of perfluorocarboxylic acids (PFCAs). Quantification of FTOHs and their degradation products can help shed light on the sources and fates of PFCAs in the environment. In this study, an analytical method was developed for the determination of 6:2 and 8:2 FTOHs, and their degradation products of poly- and perfluorinated acids, including fluorotelomer saturated and unsaturated carboxylic acids (FTCAs and FTUCAs), secondary polyfluorinated alcohols and PFCAs in biosolids-amended soils and plants using ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The extract efficiencies of different methods including ethyl acetate and methanol (MeOH) for FTOHs and acetonitrile, MeOH, methyl tert-butyl ether (MTBE), NaOH-MeOH and NaOH-MTBE for poly- and perfluorinated acids were tested. The results showed that 6:2 and 8:2 FTOHs and their degradation products could be simultaneously and satisfactorily extracted by MeOH, cleaned up by Envi-Carb graphitized carbon and solid phase extraction, respectively, and determined by UPLC-MS/MS separately. NaOH in the extractant caused the conversion of 6:2 FTCA and 8:2 FTCA into the corresponding FTUCAs. The selected methods have matrix recoveries ranged from 52% to 102%, and detection limits of 0.01-0.46ng/g dry weight for FTOHs and their degradation products in soil and plant. The optimized method was applied successfully to quantify FTOHs and their degradation products in two biosolids-amended soils and plants. The total concentrations of FTOHs in the soils were 44.1±5.8 and 82.6±7.1ng/g, and in plants tissues 3.58±0.25 and 8.33±0.66ng/g. The total concentrations of poly- and perfluorinated acids in the soils were 168.0±13.2 and 349.6±11.2ng/g, and in plants tissues 78.0±6.4 and 75.5±5.3ng/g. Copyright © 2015 Elsevier B.V. All rights reserved.

Multi-stage approach to estimate forest biomass in degraded area by fire and selective logging

NASA Astrophysics Data System (ADS)

Santos, E. G.; Shimabukuro, Y. E.; Arai, E.; Duarte, V.; Jorge, A.; Gasparini, K.

2017-12-01

The Amazon forest has been the target of several threats throughout the years. Anthropogenic disturbances in the region can significantly alter this environment, affecting directly the dynamics and structure of tropical forests. Monitoring these threats of forest degradation across the Amazon is of paramount to understand the impacts of disturbances in the tropics. With the advance of new technologies such as Light Detection and Ranging (LiDAR) the quantification and development of methodologies to monitor forest degradation in the Amazon is possible and may bring considerable contributions to this topic. The objective of this study was to use remote sensing data to assess and estimate the aboveground biomass (AGB) across different levels of degradation (fire and selective logging) using multi-stage approach between airborne LiDAR and orbital image. The study area is in the northern part of the state of Mato Grosso, Brazil. It is predominantly characterized by agricultural land and remnants of the Amazon Forest intact and degraded by either anthropic or natural reasons (selective logging and/or fire). More specifically, the study area corresponds to path/row 226/69 of OLI/Landsat 8 image. With a forest mask generated from the multi-resolution segmentation, agriculture and forest areas, forest biomass was calculated from LiDAR data and correlated with texture images, vegetation indices and fraction images by Linear Spectral Unmixing of OLI/Landsat 8 image and extrapolated to the entire scene 226/69 and validated with field inventories. The results showed that there is a moderate to strong correlation between forest biomass and texture data, vegetation indices and fraction images. With that, it is possible to extract biomass information and create maps using optical data, specifically by combining vegetation indices, which contain forest greening information with texture data that contains forest structure information. Then it was possible to extrapolate the biomass

Optimization of planting pattern plan in Logung irrigation area using linear program

NASA Astrophysics Data System (ADS)

Wardoyo, Wasis; Setyono

2018-03-01

Logung irrigation area is located in Kudus Regency, Central Java Province, Indonesia. Irrigation area with 2810 Ha of extent is getting water supply from Logung dam. Yet, the utilization of water at Logung dam is not optimal and the distribution of water is still not evenly distributed. Therefore, this study will discuss about the optimization of irrigation water utilization based on the beginning of plant season. This optimization begins with the analysis of hydrology, climatology and river discharge in order to determine the irrigation water needs. After determining irrigation water needs, six alternatives of planting patterns with the different early planting periods, i.e. 1st November, 2nd November, 3rd November, 1st December, 2nd December, and 3rd December with the planting pattern of rice-secondary crop-sugarcane is introduced. It is continued by the analysis of water distribution conducted using linear program assisted by POM-Quantity method for Windows 3 with the reliable discharge limit and the available land area. Output of this calculation are to determine the land area that can be planted based on the type of plant and growing season, and to obtaine the profits of harvest yields. Based on the optimum area of each plant species with 6 alternatives, the most optimum area was obtained at the early planting periods on 3rd December with the production profit of Rp 113.397.338.854,- with the planting pattern of rice / beans / sugarcane-rice / beans / sugarcane-beans / sugarcane.

A survey of exotic plants in federal wilderness areas

Treesearch

Marilyn Marler

2000-01-01

I conducted a survey of wilderness areas to provide an overview of plant invasions in the National Wilderness Preservation System. Fifteen per cent of responding mangers reported that exotic plants were among their top 10 management concerns, either because they are actively dealing with control of exotic pest plants or have prioritized prevention of their...

EBS7 is a plant-specific component of a highly conserved endoplasmic reticulum-associated degradation system in Arabidopsis

PubMed Central

Liu, Yidan; Zhang, Congcong; Wang, Dinghe; Su, Wei; Liu, Linchuan; Wang, Muyang; Li, Jianming

2015-01-01

Endoplasmic reticulum (ER)-associated degradation (ERAD) is an essential part of an ER-localized protein quality-control system for eliminating terminally misfolded proteins. Recent studies have demonstrated that the ERAD machinery is conserved among yeast, animals, and plants; however, it remains unknown if the plant ERAD system involves plant-specific components. Here we report that the Arabidopsis ethyl methanesulfonate-mutagenized brassinosteroid-insensitive 1 suppressor 7 (EBS7) gene encodes an ER membrane-localized ERAD component that is highly conserved in land plants. Loss-of-function ebs7 mutations prevent ERAD of brassinosteroid insensitive 1-9 (bri1-9) and bri1-5, two ER-retained mutant variants of the cell-surface receptor for brassinosteroids (BRs). As a result, the two mutant receptors accumulate in the ER and consequently leak to the plasma membrane, resulting in the restoration of BR sensitivity and phenotypic suppression of the bri1-9 and bri1-5 mutants. EBS7 accumulates under ER stress, and its mutations lead to hypersensitivity to ER and salt stresses. EBS7 interacts with the ER membrane-anchored ubiquitin ligase Arabidopsis thaliana HMG-CoA reductase degradation 1a (AtHrd1a), one of the central components of the Arabidopsis ERAD machinery, and an ebs7 mutation destabilizes AtHrd1a to reduce polyubiquitination of bri1-9. Taken together, our results uncover a plant-specific component of a plant ERAD pathway and also suggest its likely biochemical function. PMID:26371323

Enrichment and broad representation of plant biomass-degrading enzymes in the specialized hyphal swellings of Leucoagaricus gongylophorus, the fungal symbiont of leaf-cutter ants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel M.

Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plantmore » biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.« less

Enrichment and broad representation of plant biomass-degrading enzymes in the specialized hyphal swellings of Leucoagaricus gongylophorus, the fungal symbiont of leaf-cutter ants

DOE PAGES

Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel M.; ...

2015-08-28

Leaf-cutter ants are prolific and conspicuous constituents of Neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as ants incorporate it into the fungus garden. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plantmore » biomass, only a few enzymes present in these hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous plant biomass-degrading enzymes likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three quarters of all biomass-degrading enzymes identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 40 of these enzymes enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.« less

Characterization of three plant biomass-degrading microbial consortia by metagenomics- and metasecretomics-based approaches.

PubMed

Jiménez, Diego Javier; de Lima Brossi, Maria Julia; Schückel, Julia; Kračun, Stjepan Krešimir; Willats, William George Tycho; van Elsas, Jan Dirk

2016-12-01

The selection of microbes by enrichment on plant biomass has been proposed as an efficient way to develop new strategies for lignocellulose saccharification. Here, we report an in-depth analysis of soil-derived microbial consortia that were trained to degrade once-used wheat straw (WS1-M), switchgrass (SG-M) and corn stover (CS-M) under aerobic and mesophilic conditions. Molecular fingerprintings, bacterial 16S ribosomal RNA (rRNA) gene amplicon sequencing and metagenomic analyses showed that the three microbial consortia were taxonomically distinct. Based on the taxonomic affiliation of protein-encoding sequences, members of the Bacteroidetes (e.g. Chryseobacterium, Weeksella, Flavobacterium and Sphingobacterium) were preferentially selected on WS1-M, whereas SG-M and CS-M favoured members of the Proteobacteria (e.g. Caulobacter, Brevundimonas, Stenotrophomonas and Xanthomonas). The highest degradation rates of lignin (~59 %) were observed with SG-M, whereas CS-M showed a high consumption of cellulose and hemicellulose. Analyses of the carbohydrate-active enzymes in the three microbial consortia showed the dominance of glycosyl hydrolases (e.g. of families GH3, GH43, GH13, GH10, GH29, GH28, GH16, GH4 and GH92). In addition, proteins of families AA6, AA10 and AA2 were detected. Analysis of secreted protein fractions (metasecretome) for each selected microbial consortium mainly showed the presence of enzymes able to degrade arabinan, arabinoxylan, xylan, β-glucan, galactomannan and rhamnogalacturonan. Notably, these metasecretomes contain enzymes that enable us to produce oligosaccharides directly from wheat straw, sugarcane bagasse and willow. Thus, the underlying microbial consortia constitute valuable resources for the production of enzyme cocktails for the efficient saccharification of plant biomass.

Seismic Fragility Analysis of a Degraded Condensate Storage Tank

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nie, J.; Braverman, J.; Hofmayer, C.

2011-05-16

The Korea Atomic Energy Research Institute (KAERI) and Brookhaven National Laboratory are conducting a collaborative research project to develop seismic capability evaluation technology for degraded structures and components in nuclear power plants (NPPs). One of the goals of this collaboration endeavor is to develop seismic fragility analysis methods that consider the potential effects of age-related degradation of structures, systems, and components (SSCs). The essential part of this collaboration is aimed at achieving a better understanding of the effects of aging on the performance of SSCs and ultimately on the safety of NPPs. A recent search of the degradation occurrences ofmore » structures and passive components (SPCs) showed that the rate of aging related degradation in NPPs was not significantly large but increasing, as the plants get older. The slow but increasing rate of degradation of SPCs can potentially affect the safety of the older plants and become an important factor in decision making in the current trend of extending the operating license period of the plants (e.g., in the U.S. from 40 years to 60 years, and even potentially to 80 years). The condition and performance of major aged NPP structures such as the containment contributes to the life span of a plant. A frequent misconception of such low degradation rate of SPCs is that such degradation may not pose significant risk to plant safety. However, under low probability high consequence initiating events, such as large earthquakes, SPCs that have slowly degraded over many years could potentially affect plant safety and these effects need to be better understood. As part of the KAERI-BNL collaboration, a condensate storage tank (CST) was analyzed to estimate its seismic fragility capacities under various postulated degradation scenarios. CSTs were shown to have a significant impact on the seismic core damage frequency of a nuclear power plant. The seismic fragility capacity of the CST was

Rhizoremediation of diesel-contaminated soil with two rapeseed varieties and petroleum degraders reveals different responses of the plant defense mechanisms.

PubMed

Wojtera-Kwiczor, Joanna; Zukowska, Weronika; Graj, Weronika; Małecka, Arleta; Piechalak, Aneta; Ciszewska, Liliana; Chrzanowski, Łukasz; Lisiecki, Piotr; Komorowicz, Izabela; Barałkiewicz, Danuta; Voss, Ingo; Scheibe, Renate; Tomaszewska, Barbara

2014-01-01

Plant-assisted bioremediation (rhizoremediation) stands out as a potential tool to inactivate or completely remove xenobiotics from the polluted environment. Therefore, it is of key importance to find an adequate combination of plant species and microorganisms that together enhance the clean-up process. To understand the response of plants upon bioaugmentation, the antioxidative and detoxification system was analyzed in high and low erucic acid rapeseed varieties (HEAR and LEAR, respectively), after 8 weeks of their treatment with petroleum degraders and 6000 mg diesel oil/kg dry soil. The oxidative stress was enhanced in LEAR being exposed to sole diesel oil, in comparison with HEAR. However, when LEAR plants were additionally inoculated with bacteria, suppression of total catalase (CAT) and ascorbate peroxidase (APX) activity were observed. Interestingly, glutathione transferase (GST) activity was found in these plants at a much higher level than in HEAR, which correlated with a more efficient diesel removal performed by LEAR in the polluted soil and upon bioaugmentation. A distinct profile of polycyclic aromatic hydrocarbons (PAH) was detected in leaves of these plants. Neither LEAR nor HEAR experienced any changes in the photosynthetic capacity upon diesel pollution and presence of petroleum degraders, which supports the usefulness of rhizoremediation with rapeseed.

Molecular docking and dynamics simulation analyses unraveling the differential enzymatic catalysis by plant and fungal laccases with respect to lignin biosynthesis and degradation.

PubMed

Awasthi, Manika; Jaiswal, Nivedita; Singh, Swati; Pandey, Veda P; Dwivedi, Upendra N

2015-09-01

Laccase, widely distributed in bacteria, fungi, and plants, catalyzes the oxidation of wide range of compounds. With regards to one of the important physiological functions, plant laccases are considered to catalyze lignin biosynthesis while fungal laccases are considered for lignin degradation. The present study was undertaken to explain this dual function of laccases using in-silico molecular docking and dynamics simulation approaches. Modeling and superimposition analyses of one each representative of plant and fungal laccases, namely, Populus trichocarpa and Trametes versicolor, respectively, revealed low level of similarity in the folding of two laccases at 3D levels. Docking analyses revealed significantly higher binding efficiency for lignin model compounds, in proportion to their size, for fungal laccase as compared to that of plant laccase. Residues interacting with the model compounds at the respective enzyme active sites were found to be in conformity with their role in lignin biosynthesis and degradation. Molecular dynamics simulation analyses for the stability of docked complexes of plant and fungal laccases with lignin model compounds revealed that tetrameric lignin model compound remains attached to the active site of fungal laccase throughout the simulation period, while it protrudes outwards from the active site of plant laccase. Stability of these complexes was further analyzed on the basis of binding energy which revealed significantly higher stability of fungal laccase with tetrameric compound than that of plant. The overall data suggested a situation favorable for the degradation of lignin polymer by fungal laccase while its synthesis by plant laccase.

Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria

PubMed Central

Beltran-Garcia, Miguel J.; White, Jr., James F.; Prado, Fernanda M.; Prieto, Katia R.; Yamaguchi, Lydia F.; Torres, Monica S.; Kato, Massuo J.; Medeiros, Marisa H. G.; Di Mascio, Paolo

2014-01-01

Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from 15N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with 15NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of 15N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes. PMID:25374146

Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria.

PubMed

Beltran-Garcia, Miguel J; White, James F; Prado, Fernanda M; Prieto, Katia R; Yamaguchi, Lydia F; Torres, Monica S; Kato, Massuo J; Medeiros, Marisa H G; Di Mascio, Paolo

2014-11-06

Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from (15)N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with (15)NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of (15)N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes.

Effects of Alien Plants on Ecosystem Structure and Functioning and Implications for Restoration: Insights from Three Degraded Sites in South African Fynbos

NASA Astrophysics Data System (ADS)

Gaertner, Mirijam; Richardson, David M.; Privett, Sean D. J.

2011-07-01

We investigated the type and extent of degradation at three sites on the Agulhas Plain, South Africa: an old field dominated by the alien grass Pennisetum clandestinum Pers . (kikuyu), an abandoned Eucalyptus plantation, and a natural fynbos community invaded by nitrogen fixing—Australian Acacia species. These forms of degradation are representative of many areas in the region. By identifying the nature and degree of ecosystem degradation we aimed to determine appropriate strategies for restoration in this biodiversity hotspot. Vegetation surveys were conducted at degraded sites and carefully selected reference sites. Soil-stored propagule seed banks and macro- and micro-soil nutrients were determined. Species richness, diversity and native cover under Eucalyptus were extremely low compared to the reference site and alterations of the soil nutrients were the most severe. The cover of indigenous species under Acacia did not differ significantly from that in reference sites, but species richness was lower under Acacia and soils were considerably enriched. Native species richness was much lower in the kikuyu site, but soil nutrient status was similar to the reference site. Removal of the alien species alone may be sufficient to re-initiate ecosystem recovery at the kikuyu site, whereas active restoration is required to restore functioning ecosystems dominated by native species in the Acacia thicket and the Eucalyptus plantation. To restore native plant communities we suggest burning, mulching with sawdust and sowing of native species.

Application of carbohydrate arrays coupled with mass spectrometry to detect activity of plant-polysaccharide degradative enzymes from the fungus Aspergillus niger

PubMed Central

van Munster, Jolanda M.; Thomas, Baptiste; Riese, Michel; Davis, Adrienne L.; Gray, Christopher J.; Archer, David B.; Flitsch, Sabine L.

2017-01-01

Renewables-based biotechnology depends on enzymes to degrade plant lignocellulose to simple sugars that are converted to fuels or high-value products. Identification and characterization of such lignocellulose degradative enzymes could be fast-tracked by availability of an enzyme activity measurement method that is fast, label-free, uses minimal resources and allows direct identification of generated products. We developed such a method by applying carbohydrate arrays coupled with MALDI-ToF mass spectrometry to identify reaction products of carbohydrate active enzymes (CAZymes) of the filamentous fungus Aspergillus niger. We describe the production and characterization of plant polysaccharide-derived oligosaccharides and their attachment to hydrophobic self-assembling monolayers on a gold target. We verify effectiveness of this array for detecting exo- and endo-acting glycoside hydrolase activity using commercial enzymes, and demonstrate how this platform is suitable for detection of enzyme activity in relevant biological samples, the culture filtrate of A. niger grown on wheat straw. In conclusion, this versatile method is broadly applicable in screening and characterisation of activity of CAZymes, such as fungal enzymes for plant lignocellulose degradation with relevance to biotechnological applications as biofuel production, the food and animal feed industry. PMID:28220903

Application of carbohydrate arrays coupled with mass spectrometry to detect activity of plant-polysaccharide degradative enzymes from the fungus Aspergillus niger.

PubMed

van Munster, Jolanda M; Thomas, Baptiste; Riese, Michel; Davis, Adrienne L; Gray, Christopher J; Archer, David B; Flitsch, Sabine L

2017-02-21

Renewables-based biotechnology depends on enzymes to degrade plant lignocellulose to simple sugars that are converted to fuels or high-value products. Identification and characterization of such lignocellulose degradative enzymes could be fast-tracked by availability of an enzyme activity measurement method that is fast, label-free, uses minimal resources and allows direct identification of generated products. We developed such a method by applying carbohydrate arrays coupled with MALDI-ToF mass spectrometry to identify reaction products of carbohydrate active enzymes (CAZymes) of the filamentous fungus Aspergillus niger. We describe the production and characterization of plant polysaccharide-derived oligosaccharides and their attachment to hydrophobic self-assembling monolayers on a gold target. We verify effectiveness of this array for detecting exo- and endo-acting glycoside hydrolase activity using commercial enzymes, and demonstrate how this platform is suitable for detection of enzyme activity in relevant biological samples, the culture filtrate of A. niger grown on wheat straw. In conclusion, this versatile method is broadly applicable in screening and characterisation of activity of CAZymes, such as fungal enzymes for plant lignocellulose degradation with relevance to biotechnological applications as biofuel production, the food and animal feed industry.

Redmedial Action, Decision Document, Leaseback Area, Alabama Army Ammunition Plant

DTIC Science & Technology

1988-02-01

Draft Report, Environmental Science and Engineering, Inc. (ESE), 1980. o Final Report for the Alabama Army Ammunition Plant, Leaseback Area...Requirements for the GSA and Leaseback Areas at the AAAP, Draft Report. Environmental Science and Engineering, Inc.(ESE), 1980. o Alabama Army...Ammunition Plant, Feasibility Study, Draft Report, Environmental Science and Engineering, Inc. (ESE), 1986. o Environmental Survey of Alabama Army Ammunition

Solar photocatalytic degradation of some hazardous water-soluble pesticides at pilot-plant scale.

PubMed

Oller, I; Gernjak, W; Maldonado, M I; Pérez-Estrada, L A; Sánchez-Pérez, J A; Malato, S

2006-12-01

The technical feasibility and performance of photocatalytic degradation of six water-soluble pesticides (cymoxanil, methomyl, oxamyl, dimethoate, pyrimethanil and telone) have been studied at pilot-plant scale in two well-defined systems which are of special interest because natural solar UV light can be used: heterogeneous photocatalysis with titanium dioxide and homogeneous photocatalysis by photo-Fenton. TiO(2) photocatalysis tests were performed in a 35L solar pilot plant with three Compound Parabolic Collectors (CPCs) under natural illumination and a 75L solar pilot plant with four CPC units was used for homogeneous photocatalysis tests. The initial pesticide concentration studied was 50 mg L(-1) and the catalyst concentrations employed were 200 mg L(-1) of TiO(2) and 20 mg L(-1) of iron. Both toxicity (Vibrio fischeri, Biofix) and biodegradability (Zahn-Wellens test) of the initial pesticide solutions were also measured. Total disappearance of the parent compounds and nearly complete mineralization were attained with all pesticides tested. Treatment time, hydrogen peroxide consumption and release of heteroatoms are discussed.

Individual tree detection in intact forest and degraded forest areas in the north region of Mato Grosso State, Brazilian Amazon

NASA Astrophysics Data System (ADS)

Santos, E. G.; Jorge, A.; Shimabukuro, Y. E.; Gasparini, K.

2017-12-01

The State of Mato Grosso - MT has the second largest area with degraded forest among the states of the Brazilian Legal Amazon. Land use and land cover change processes that occur in this region cause the loss of forest biomass, releasing greenhouse gases that contribute to the increase of temperature on earth. These degraded forest areas lose biomass according to the intensity and magnitude of the degradation type. The estimate of forest biomass, commonly performed by forest inventory through sample plots, shows high variance in degraded forest areas. Due to this variance and complexity of tropical forests, the aim of this work was to estimate forest biomass using LiDAR point clouds in three distinct forest areas: one degraded by fire, another by selective logging and one area of intact forest. The approach applied in these areas was the Individual Tree Detection (ITD). To isolate the trees, we generated Canopy Height Models (CHM) images, which are obtained by subtracting the Digital Elevation Model (MDE) and the Digital Terrain Model (MDT), created by the cloud of LiDAR points. The trees in the CHM images are isolated by an algorithm provided by the Quantitative Ecology research group at the School of Forestry at Northern Arizona University (SILVA, 2015). With these points, metrics were calculated for some areas, which were used in the model of biomass estimation. The methodology used in this work was expected to reduce the error in biomass estimate in the study area. The cloud points of the most representative trees were analyzed, and thus field data was correlated with the individual trees found by the proposed algorithm. In a pilot study, the proposed methodology was applied generating the individual tree metrics: total height and area of the crown. When correlating 339 isolated trees, an unsatisfactory R² was obtained, as heights found by the algorithm were lower than those obtained in the field, with an average difference of 2.43 m. This shows that the

Rumen Bacterial Degradation of Forage Cell Walls Investigated by Electron Microscopy

PubMed Central

Akin, Danny E.; Amos, Henry E.

1975-01-01

The association of rumen bacteria with specific leaf tissues of the forage grass Kentucky-31 tall fescue (Festuca arundinacea Schreb.) during in vitro degradation was investigated by transmission and scanning electron microscopy. Examination of degraded leaf cross-sections revealed differential rates of tissue degradation in that the cell walls of the mesophyll and pholem were degraded prior to those of the outer bundle sheath and epidermis. Rumen bacteria appeared to degrade the mesophyll, in some cases, and phloem without prior attachment to the plant cell walls. The degradation of bundle sheath and epidermal cell walls appeared to be preceded by attachment of bacteria to the plant cell wall. Ultrastructural features apparently involved in the adhesion of large cocci to plant cells were observed by transmission and scanning electron microscopy. The physical association between plant and rumen bacterial cells during degradation apparently varies with tissue types. Bacterial attachment, by extracellular features in some microorganisms, is required prior to degradation of the more resistant tissues. Images PMID:16350017

The conservation of native priority medicinal plants in a Caatinga area in Ceará, northeastern Brazil.

PubMed

Santos, Maria O; Almeida, Bianca V DE; Ribeiro, Daiany A; Macêdo, Delmacia G DE; Macêdo, Márcia J F; Macedo, Julimery G F; Sousa, Francisca F S DE; Oliveira, Liana G S DE; Saraiva, Manuele E; Araújo, Thatiane M S; Souza, Marta M A

2017-01-01

Much of the Brazilian semiarid region faces a considerable process of degradation of natural resources, and ethnobotanical studies have collaborated with important information about the use and traditional knowledge, serving as a tool to design conservation strategies of native plant species. Thus, this study aimed to determine medicinal species meriting conservation priorities in a "Caatinga" area in the northeastern of Brazilian territory. The ethnobotanical data were collected through semi-structured interviews with key subjects selected through the "snowball" technique. The availability and species conservation priority was verified by relative density, risk of collection, local use and use of diversity in the forest fragment sampled. It was recorded 42 native medicinal plants and conservation priority score was calculated for seven species, including Mimosa tenuiflora, Hymenaea courbaril, Ximenia americana and Amburana cearensis need immediate conservation and attention, since their collection does not occur in a sustainable way. In order to ensure the perpetuation of the species and the sustainability of traditional therapeutic practice there needs to be a development of conservation practices of caatinga remaining to better conserve the species of the biome.

Genomic characterization of plant cell wall degrading enzymes and in silico analysis of xylanases and polygalacturonases of Fusarium virguliforme.

PubMed

Chang, Hao-Xun; Yendrek, Craig R; Caetano-Anolles, Gustavo; Hartman, Glen L

2016-07-12

Plant cell wall degrading enzymes (PCWDEs) are a subset of carbohydrate-active enzymes (CAZy) produced by plant pathogens to degrade plant cell walls. To counteract PCWDEs, plants release PCWDEs inhibitor proteins (PIPs) to reduce their impact. Several transgenic plants expressing exogenous PIPs that interact with fungal glycoside hydrolase (GH)11-type xylanases or GH28-type polygalacturonase (PG) have been shown to enhance disease resistance. However, many plant pathogenic Fusarium species were reported to escape PIPs inhibition. Fusarium virguliforme is a soilborne pathogen that causes soybean sudden death syndrome (SDS). Although the genome of F. virguliforme was sequenced, there were limited studies focused on the PCWDEs of F. virguliforme. Our goal was to understand the genomic CAZy structure of F. viguliforme, and determine if exogenous PIPs could be theoretically used in soybean to enhance resistance against F. virguliforme. F. virguliforme produces diverse CAZy to degrade cellulose and pectin, similar to other necrotorphic and hemibiotrophic plant pathogenic fungi. However, some common CAZy of plant pathogenic fungi that catalyze hemicellulose, such as GH29, GH30, GH44, GH54, GH62, and GH67, were deficient in F. virguliforme. While the absence of these CAZy families might be complemented by other hemicellulases, F. virguliforme contained unique families including GH131, polysaccharide lyase (PL) 9, PL20, and PL22 that were not reported in other plant pathogenic fungi or oomycetes. Sequence analysis revealed two GH11 xylanases of F. virguliforme, FvXyn11A and FvXyn11B, have conserved residues that allow xylanase inhibitor protein I (XIP-I) binding. Structural modeling suggested that FvXyn11A and FvXyn11B could be blocked by XIP-I that serves as good candidate for developing transgenic soybeans. In contrast, one GH28 PG, FvPG2, contains an amino acid substitution that is potentially incompatible with the bean polygalacturonase-inhibitor protein II (PvPGIP2

The Potential Role of Arbuscular Mycorrhizal Fungi in the Restoration of Degraded Lands

PubMed Central

Asmelash, Fisseha; Bekele, Tamrat; Birhane, Emiru

2016-01-01

Experiences worldwide reveal that degraded lands restoration projects achieve little success or fail. Hence, understanding the underlying causes and accordingly, devising appropriate restoration mechanisms is crucial. In doing so, the ever-increasing aspiration and global commitments in degraded lands restoration could be realized. Here we explain that arbuscular mycorrhizal fungi (AMF) biotechnology is a potential mechanism to significantly improve the restoration success of degraded lands. There are abundant scientific evidences to demonstrate that AMF significantly improve soil attributes, increase above and belowground biodiversity, significantly improve tree/shrub seedlings survival, growth and establishment on moisture and nutrient stressed soils. AMF have also been shown to drive plant succession and may prevent invasion by alien species. The very few conditions where infective AMF are low in abundance and diversity is when the soil erodes, is disturbed and is devoid of vegetation cover. These are all common features of degraded lands. Meanwhile, degraded lands harbor low levels of infective AMF abundance and diversity. Therefore, the successful restoration of infective AMF can potentially improve the restoration success of degraded lands. Better AMF inoculation effects result when inocula are composed of native fungi instead of exotics, early seral instead of late seral fungi, and are consortia instead of few or single species. Future research efforts should focus on AMF effect on plant community primary productivity and plant competition. Further investigation focusing on forest ecosystems, and carried out at the field condition is highly recommended. Devising cheap and ethically widely accepted inocula production methods and better ways of AMF in situ management for effective restoration of degraded lands will also remain to be important research areas. PMID:27507960

Expanding Kenya's protected areas under the Convention on Biological Diversity to maximize coverage of plant diversity.

PubMed

Scherer, Laura; Curran, Michael; Alvarez, Miguel

2017-04-01

Biodiversity is highly valuable and critically threatened by anthropogenic degradation of the natural environment. In response, governments have pledged enhanced protected-area coverage, which requires scarce biological data to identify conservation priorities. To assist this effort, we mapped conservation priorities in Kenya based on maximizing alpha (species richness) and beta diversity (species turnover) of plant communities while minimizing economic costs. We used plant-cover percentages from vegetation surveys of over 2000 plots to build separate models for each type of diversity. Opportunity and management costs were based on literature data and interviews with conservation organizations. Species richness was predicted to be highest in a belt from Lake Turkana through Mount Kenya and in a belt parallel to the coast, and species turnover was predicted to be highest in western Kenya and along the coast. Our results suggest the expanding reserve network should focus on the coast and northeastern provinces of Kenya, where new biological surveys would also fill biological data gaps. Meeting the Convention on Biological Diversity target of 17% terrestrial coverage by 2020 would increase representation of Kenya's plant communities by 75%. However, this would require about 50 times more funds than Kenya has received thus far from the Global Environment Facility. © 2016 Society for Conservation Biology.

A global synthesis of plant extinction rates in urban areas.

PubMed

Hahs, Amy K; McDonnell, Mark J; McCarthy, Michael A; Vesk, Peter A; Corlett, Richard T; Norton, Briony A; Clemants, Steven E; Duncan, Richard P; Thompson, Ken; Schwartz, Mark W; Williams, Nicholas S G

2009-11-01

Plant extinctions from urban areas are a growing threat to biodiversity worldwide. To minimize this threat, it is critical to understand what factors are influencing plant extinction rates. We compiled plant extinction rate data for 22 cities around the world. Two-thirds of the variation in plant extinction rates was explained by a combination of the city's historical development and the current proportion of native vegetation, with the former explaining the greatest variability. As a single variable, the amount of native vegetation remaining also influenced extinction rates, particularly in cities > 200 years old. Our study demonstrates that the legacies of landscape transformations by agrarian and urban development last for hundreds of years, and modern cities potentially carry a large extinction debt. This finding highlights the importance of preserving native vegetation in urban areas and the need for mitigation to minimize potential plant extinctions in the future.

Determinants of farmers' tree-planting investment decisions as a degraded landscape management strategy in the central highlands of Ethiopia

NASA Astrophysics Data System (ADS)

Gessesse, Berhan; Bewket, Woldeamlak; Bräuning, Achim

2016-04-01

Land degradation due to lack of sustainable land management practices is one of the critical challenges in many developing countries including Ethiopia. This study explored the major determinants of farm-level tree-planting decisions as a land management strategy in a typical farming and degraded landscape of the Modjo watershed, Ethiopia. The main data were generated from household surveys and analysed using descriptive statistics and a binary logistic regression model. The model significantly predicted farmers' tree-planting decisions (χ2 = 37.29, df = 15, P < 0.001). Besides, the computed significant value of the model revealed that all the considered predictor variables jointly influenced the farmers' decisions to plant trees as a land management strategy. The findings of the study demonstrated that the adoption of tree-growing decisions by local land users was a function of a wide range of biophysical, institutional, socioeconomic and household-level factors. In this regard, the likelihood of household size, productive labour force availability, the disparity of schooling age, level of perception of the process of deforestation and the current land tenure system had a critical influence on tree-growing investment decisions in the study watershed. Eventually, the processes of land-use conversion and land degradation were serious, which in turn have had adverse effects on agricultural productivity, local food security and poverty trap nexus. Hence, the study recommended that devising and implementing sustainable land management policy options would enhance ecological restoration and livelihood sustainability in the study watershed.

Determinants of farmers' tree planting investment decision as a degraded landscape management strategy in the central highlands of Ethiopia

NASA Astrophysics Data System (ADS)

Gessesse, B.; Bewket, W.; Bräuning, A.

2015-11-01

Land degradation due to lack of sustainable land management practices are one of the critical challenges in many developing countries including Ethiopia. This study explores the major determinants of farm level tree planting decision as a land management strategy in a typical framing and degraded landscape of the Modjo watershed, Ethiopia. The main data were generated from household surveys and analysed using descriptive statistics and binary logistic regression model. The model significantly predicted farmers' tree planting decision (Chi-square = 37.29, df = 15, P<0.001). Besides, the computed significant value of the model suggests that all the considered predictor variables jointly influenced the farmers' decision to plant trees as a land management strategy. In this regard, the finding of the study show that local land-users' willingness to adopt tree growing decision is a function of a wide range of biophysical, institutional, socioeconomic and household level factors, however, the likelihood of household size, productive labour force availability, the disparity of schooling age, level of perception of the process of deforestation and the current land tenure system have positively and significantly influence on tree growing investment decisions in the study watershed. Eventually, the processes of land use conversion and land degradation are serious which in turn have had adverse effects on agricultural productivity, local food security and poverty trap nexus. Hence, devising sustainable and integrated land management policy options and implementing them would enhance ecological restoration and livelihood sustainability in the study watershed.

Leaf mass per area, not total leaf area, drives differences in above-ground biomass distribution among woody plant functional types.

PubMed

Duursma, Remko A; Falster, Daniel S

2016-10-01

Here, we aim to understand differences in biomass distribution between major woody plant functional types (PFTs) (deciduous vs evergreen and gymnosperm vs angiosperm) in terms of underlying traits, in particular the leaf mass per area (LMA) and leaf area per unit stem basal area. We used a large compilation of plant biomass and size observations, including observations of 21 084 individuals on 656 species. We used a combination of semiparametric methods and variance partitioning to test the influence of PFT, plant height, LMA, total leaf area, stem basal area and climate on above-ground biomass distribution. The ratio of leaf mass to above-ground woody mass (MF /MS ) varied strongly among PFTs. We found that MF /MS at a given plant height was proportional to LMA across PFTs. As a result, the PFTs did not differ in the amount of leaf area supported per unit above-ground biomass or per unit stem basal area. Climate consistently explained very little additional variation in biomass distribution at a given plant size. Combined, these results demonstrate consistent patterns in above-ground biomass distribution and leaf area relationships among major woody PFTs, which can be used to further constrain global vegetation models. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Response of graywater recycling systems based on hydroponic plant growth to three classes of surfactants

NASA Technical Reports Server (NTRS)

Garland, J. L.; Levine, L. H.; Yorio, N. C.; Hummerick, M. E.

2004-01-01

Anionic (sodium laureth sulfate, SLES), amphoteric (cocamidopropyl betaine, CAPB) and nonionic (alcohol polyethoxylate, AE) surfactants were added to separate nutrient film technique (NFT) hydroponic systems containing dwarf wheat (Triticum aestivum cv. USU Apogee) in a series of 21 day trials. Surfactant was added either in a (1). temporally dynamic mode (1-3 g surfactant m(-2) growing area d(-1)) as effected by automatic addition of a 300 ppm surfactant solution to meet plant water demand, or (2). continuous mode (2 g surfactant m(-2) growing area d(-1)) as effected by slow addition (10 mLh(-1)) of a 2000 ppm surfactant solution beginning at 4d after planting. SLES showed rapid primary degradation in both experiments, with no accumulation 24 h after initial addition. CAPB and AE were degraded less rapidly, with 30-50% remaining 24 h after initial addition, but CAPB and AE levels were below detection limit for the remainder of the study. No reductions in vegetative growth of wheat were observed in response to SLES, but biomass was reduced 20-25% with CAPB and AE. Microbial communities associated with both the plant roots and wetted hardware surfaces actively degraded the surfactants, as determined by monitoring surfactant levels following pulse additions at day 20 (with plants) and day 21 (after plant removal). In order to test whether the biofilm communities could ameliorate phytotoxicity by providing a microbial community acclimated for CAPB and AE decay, the continuous exposure systems were planted with wheat seeds after crop removal at day 21. Acclimation resulted in faster primary degradation (>90% within 24h) and reduced phytotoxicity. Overall, the studies indicate that relatively small areas (3-5m(2)) of hydroponic plant systems can process per capita production of mixed surfactants (5-10 g x person(-1)d(-1)) with minimal effects on plant growth.

DDE remediation and degradation.

PubMed

Thomas, John E; Ou, Li-Tse; All-Agely, Abid

2008-01-01

DDT and its metabolites, DDD and DDE, have been shown to be recalcitrant to degradation. The parent compound, DDT, was used extensively worldwide starting in 1939 and was banned in the United States in 1973. The daughter compound, DDE, may result from aerobic degradation, abiotic dehydrochlorination, or photochemical decomposition. DDE has also occurred as a contaminant in commercial-grade DDT. The p,p'-DDE isomer is more biologically active than the o,p-DDE, with a reported half-life of -5.7 years. However, when DDT was repeatedly applied to the soil, the DDE concentration may remain unchanged for more than 20 yr. Remediation of DDE-contaminated soil and water may be done by several techniques. Phytoremediation involves translocating DDT, DDD, and DDE from the soil into the plant, although some aquatic species (duckweed > elodea > parrot feather) can transform DDT into predominantly DDD with some DDE being formed. Of all the plants that can uptake DDE, Cucurbita pepo has been the most extensively studied, with translocation values approaching "hyperaccumulation" levels. Soil moisture, temperature, and plant density have all been documented as important factors in the uptake of DDE by Cucurbita pepo. Uptake may also be influenced positively by amendments such as biosurfactants, mycorrhizal inoculants, and low molecular weight organic acids (e.g., citric and oxalic acids). DDE microbial degradation by dehalogenases, dioxygenases, and hydrolases occurs under the proper conditions. Although several aerobic degradation pathways have been proposed, none has been fully verified. Very few aerobic pure cultures are capable of fully degrading DDE to CO2. Cometabolism of DDE by Pseudomonas sp., Alicaligens sp., and Terrabacter sp. grown on biphenyl has been reported; however, not all bacterial species that produce biphenyl dioxygenase degraded DDE. Arsenic and copper inhibit DDE degradation by aerobic microorganisms. Similarly, metal chelates such as EDTA inhibit the

6. VIEW EAST TOWARDS LOTTSFORD BRANCH, THE AMPHITHEATRELIKE PLANTING AREA ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. VIEW EAST TOWARDS LOTTSFORD BRANCH, THE AMPHITHEATRE-LIKE PLANTING AREA ON THE SOUTH SLOPE OF WATSON'S HILL - U.S. Plant Introduction Station, Landscape, 11601 Old Pond Road, Glenn Dale, Prince George's County, MD

Status of the steam generator tube circumferential ODSCC degradation experienced at the Doel 4 plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roussel, G.

1997-02-01

Since the 1991 outage, the Doel Unit 4 nuclear power plant is known to be affected by circumferential outside diameter intergranular stress corrosion cracking at the hot leg tube expansion transition. Extensive non destructive examination inspections have shown the number of tubes affected by this problem as well as the size of the cracks to have been increasing for the three cycles up to 1993. As a result of the high percentage of tubes found non acceptable for continued service after the 1993 in-service inspection, about 1,700 mechanical sleeves were installed in the steam generators. During the 1994 outage, allmore » the tubes sleeved during the 1993 outage were considered as potentially cracked to some extent at the upper hydraulic transition and were therefore not acceptable for continued service. They were subsequently repaired by laser welding. Furthermore all the tubes not sleeved during the 1993 outage were considered as not acceptable for continued service and were repaired by installing laser welded sleeves. During the 1995 outage, some unexpected degradation phenomena were evidenced in the sleeved tubes. This paper summarizes the status of the circumferential ODSCC experienced in the SG tubes of the Doel 4 plant as well as the other connected degradation phenomena.« less

Enhanced Degradation of TCE on a Superfund Site Using Endophyte-Assisted Poplar Tree Phytoremediation.

PubMed

Doty, Sharon L; Freeman, John L; Cohu, Christopher M; Burken, Joel G; Firrincieli, Andrea; Simon, Andrew; Khan, Zareen; Isebrands, J G; Lukas, Joseph; Blaylock, Michael J

2017-09-05

Trichloroethylene (TCE) is a widespread environmental pollutant common in groundwater plumes associated with industrial manufacturing areas. We had previously isolated and characterized a natural bacterial endophyte, Enterobacter sp. strain PDN3, of poplar trees, that rapidly metabolizes TCE, releasing chloride ion. We now report findings from a successful three-year field trial of endophyte-assisted phytoremediation on the Middlefield-Ellis-Whisman Superfund Study Area TCE plume in the Silicon Valley of California. The inoculated poplar trees exhibited increased growth and reduced TCE phytotoxic effects with a 32% increase in trunk diameter compared to mock-inoculated control poplar trees. The inoculated trees excreted 50% more chloride ion into the rhizosphere, indicative of increased TCE metabolism in planta. Data from tree core analysis of the tree tissues provided further supporting evidence of the enhanced rate of degradation of the chlorinated solvents in the inoculated trees. Test well groundwater analyses demonstrated a marked decrease in concentration of TCE and its derivatives from the tree-associated groundwater plume. The concentration of TCE decreased from 300 μg/L upstream of the planted area to less than 5 μg/L downstream of the planted area. TCE derivatives were similarly removed with cis-1,2-dichloroethene decreasing from 160 μg/L to less than 5 μg/L and trans-1,2-dichloroethene decreasing from 3.1 μg/L to less than 0.5 μg/L downstream of the planted trees. 1,1-dichloroethene and vinyl chloride both decreased from 6.8 and 0.77 μg/L, respectively, to below the reporting limit of 0.5 μg/L providing strong evidence of the ability of the endophytic inoculated trees to effectively remove TCE from affected groundwater. The combination of native pollutant-degrading endophytic bacteria and fast-growing poplar tree systems offers a readily deployable, cost-effective approach for the degradation of TCE, and may help mitigate potential transfer up

Phased Restoration Plan for Degraded Land in North Korea by the Clustered Distribution Pattern of Suitable Afforestation Plants

NASA Astrophysics Data System (ADS)

Lee, S. G.; Lee, W. K.; Choi, H. A.; Yoo, H.; Song, C.; Son, Y.; Cha, S.; Bae, S. W.

2017-12-01

Degraded forest of North Korea (DPRK; The Democratic People's Republic of Koprea) is not only confined itself, it could cause serious problem in Korean Peninsula. The importance of restoration for degraded land has increased to improve an healthy ecosystem and solve a shortage of food in North Korea lately. On the other hand, although effort of North Korea government, degraded problem have consistently got worse. There are two main reasons it does not show effectively. The most critical one is absence of technique and information to restore, they concentrate urgent problem which is related to a poor food supply. The other problem is that they demand an efficiency plan in a short period. In these aspect, this study aims selecting suitable tree by spatial characteristics and establishing phased restoration plan to support policy decision about a degraded land in North Korea. The suitable tree for restoration is taken from references which involve natural plant distribution of North and South Korea (ROK; Republic of Korea). Optimal environmental predicted map is deducted from accumulated data of plant physiology whose endemic environmental optimal range individually. It is integrated a map by order of priorities that first is suitable tree species according to the region, and second is clustering distribution rate in a same species. The two types of priority is applied to weighting method. The research result shows that 23 afforestation species fit to restore, and lager distributed plants agree with the major species in Korean Peninsula. The integrated map considers weight of priorities, and it appears that Picea jezoensis is matched the widest. The integrated map shows a view of suitable restoration according to the space, but this is finespun to utilize in a policy. Therefore It provides 3 step plan to support policy decision by Block Statistics, as 12.5km (long-term general plan), 5km (medium-term detailed plan), 1km (short-term implementation plan).

Mapping the polysaccharide degradation potential of Aspergillus niger

PubMed Central

2012-01-01

Background The degradation of plant materials by enzymes is an industry of increasing importance. For sustainable production of second generation biofuels and other products of industrial biotechnology, efficient degradation of non-edible plant polysaccharides such as hemicellulose is required. For each type of hemicellulose, a complex mixture of enzymes is required for complete conversion to fermentable monosaccharides. In plant-biomass degrading fungi, these enzymes are regulated and released by complex regulatory structures. In this study, we present a methodology for evaluating the potential of a given fungus for polysaccharide degradation. Results Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this with a list of 188 genes coding for carbohydrate-active enzymes from Aspergillus niger, thus forming an analysis framework, which can be queried. Combination of this information network with gene expression analysis on mono- and polysaccharide substrates has allowed elucidation of concerted gene expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan. Conclusions The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for expression analysis of carbohydrate-active enzymes. Applying this network-based approach, we provide the first genome-scale characterization of all genes coding for carbohydrate-active enzymes identified in A. niger. PMID:22799883

Mapping the polysaccharide degradation potential of Aspergillus niger.

PubMed

Andersen, Mikael R; Giese, Malene; de Vries, Ronald P; Nielsen, Jens

2012-07-16

The degradation of plant materials by enzymes is an industry of increasing importance. For sustainable production of second generation biofuels and other products of industrial biotechnology, efficient degradation of non-edible plant polysaccharides such as hemicellulose is required. For each type of hemicellulose, a complex mixture of enzymes is required for complete conversion to fermentable monosaccharides. In plant-biomass degrading fungi, these enzymes are regulated and released by complex regulatory structures. In this study, we present a methodology for evaluating the potential of a given fungus for polysaccharide degradation. Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this with a list of 188 genes coding for carbohydrate-active enzymes from Aspergillus niger, thus forming an analysis framework, which can be queried. Combination of this information network with gene expression analysis on mono- and polysaccharide substrates has allowed elucidation of concerted gene expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan. The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for expression analysis of carbohydrate-active enzymes. Applying this network-based approach, we provide the first genome-scale characterization of all genes coding for carbohydrate-active enzymes identified in A. niger.

Degradation of 17β-Estradiol by a Gram-Negative Bacterium Isolated from Activated Sludge in a Sewage Treatment Plant in Tokyo, Japan

PubMed Central

Fujii, Katsuhiko; Kikuchi, Shintaro; Satomi, Masataka; Ushio-Sata, Noriko; Morita, Naoki

2002-01-01

A 17β-estradiol (E2)-degrading bacterium was isolated from activated sludge in a sewage treatment plant in Tokyo, Japan. The isolate was suggested to be a new Novosphingobium species. Gas chromatography-mass spectrometry and 1H nuclear magnetic resonance analyses of the metabolites of E2 degradation suggested that no toxic products accumulated in the culture medium. PMID:11916733

Genetic structure of Pilosocereus gounellei (Cactaceae) as revealed by AFLP marker to guide proposals for improvement and restoration of degraded areas in Caatinga biome.

PubMed

Monteiro, E R; Strioto, D K; Meirelles, A C S; Mangolin, C A; Machado, M F P S

2015-12-15

Amplified fragment length polymorphism (AFLP) analysis was used to evaluate DNA polymorphism in Pilosocereus gounellei with the aim of differentiating samples grown in different Brazilian semiarid regions. Seven primer pairs were used to amplify 703 AFLP markers, of which 700 (99.21%) markers were polymorphic. The percentage of polymorphic markers ranged from 95.3% for the primer combination E-AAG/M-CTT to 100% for E-ACC/M-CAT, E-ACC/M-CAA, E-AGC/M-CAG, E-ACT/M-CTA, and E-AGG/M-CTG. The largest number of informative markers (126) was detected using the primer combination E-AAC/M-CTA. Polymorphism of the amplified DNA fragments ranged from 72.55% (in sample from Piauí State) to 82.79% (in samples from Rio Grande Norte State), with an average of 75.39%. Despite the high genetic diversity of AFLP markers in xiquexique, analysis using the STRUCTURE software identified relatively homogeneous clusters of xiquexique from the same location, indicating a differentiation at the molecular level, among the plant samples from different regions of the Caatinga biome. The AFLP methodology identified genetically homogeneous and contrasting plants, as well as plants from different regions with common DNA markers. Seeds from such plants can be used for further propagation of plants for establishment of biodiversity conservation units and restoration of degraded areas of the Caatinga biome.

[Effects of large-area planting water hyacinth on macro-benthos community structure and biomass].

PubMed

Liu, Guo-Feng; Liu, Hai-Qin; Zhang, Zhi-Yong; Zhang, Ying-Ying; Yan, Shao-Hua; Zhong, Ji-Cheng; Fan, Cheng-Xin

2010-12-01

The effects on macro-benthos and benthos environment of planting 200 hm2 water hyacinth (E. crassipens) in Zhushan Bay, Lake Taihu, were studied during 8-10 months consecutive surveys. Results indicated that average densities of mollusca (the main species were Bellamya aeruginosa) in far-planting, near-planting and planting area were 276.67, 371.11 and 440.00 ind/m2, respectively, and biomass were 373.15, 486.57 and 672.54 g/m2, respectively, showed that average density and biomass of planting area's were higher than those of others. However, the average density and biomass of Oligochaeta (the main species was Limodrilus hoffmeisteri) and Chironomidae in planting area were lower than that of outside planting area. The density and biomass of three dominant species of benthic animal increased quickly during 8-9 months, decreased quickly in October inside and outside water hyacinth planting area. The reason of this phenomenon could be possible that lots of cyanobacteria cells died and consumed dissolve oxygen in proceed decomposing. Algae cells released lots of phosphorus and nitrogen simultaneously, so macro-benthos died in this environment. The indexes of Shannon-Weaver and Simpson indicated that water environment was in moderate polluted state. On the basis of the survey results, the large-area and high-density planting water hyacinth haven't demonstrated a great impact on macrobenthos and benthos environment in short planting time (about 6 months planting time).

Comparison of dwarf bamboos (Indocalamus sp.) leaf parameters to determine relationship between spatial density of plants and total leaf area per plant.

PubMed

Shi, Pei-Jian; Xu, Qiang; Sandhu, Hardev S; Gielis, Johan; Ding, Yu-Long; Li, Hua-Rong; Dong, Xiao-Bo

2015-10-01

The relationship between spatial density and size of plants is an important topic in plant ecology. The self-thinning rule suggests a -3/2 power between average biomass and density or a -1/2 power between stand yield and density. However, the self-thinning rule based on total leaf area per plant and density of plants has been neglected presumably because of the lack of a method that can accurately estimate the total leaf area per plant. We aimed to find the relationship between spatial density of plants and total leaf area per plant. We also attempted to provide a novel model for accurately describing the leaf shape of bamboos. We proposed a simplified Gielis equation with only two parameters to describe the leaf shape of bamboos one model parameter represented the overall ratio of leaf width to leaf length. Using this method, we compared some leaf parameters (leaf shape, number of leaves per plant, ratio of total leaf weight to aboveground weight per plant, and total leaf area per plant) of four bamboo species of genus Indocalamus Nakai (I. pedalis (Keng) P.C. Keng, I. pumilus Q.H. Dai and C.F. Keng, I. barbatus McClure, and I. victorialis P.C. Keng). We also explored the possible correlation between spatial density and total leaf area per plant using log-linear regression. We found that the simplified Gielis equation fit the leaf shape of four bamboo species very well. Although all these four species belonged to the same genus, there were still significant differences in leaf shape. Significant differences also existed in leaf area per plant, ratio of leaf weight to aboveground weight per plant, and leaf length. In addition, we found that the total leaf area per plant decreased with increased spatial density. Therefore, we directly demonstrated the self-thinning rule to improve light interception.

From oil spills to barley growth - oil-degrading soil bacteria and their promoting effects.

PubMed

Mikolasch, Annett; Reinhard, Anne; Alimbetova, Anna; Omirbekova, Anel; Pasler, Lisa; Schumann, Peter; Kabisch, Johannes; Mukasheva, Togzhan; Schauer, Frieder

2016-11-01

Heavy contamination of soils by crude oil is omnipresent in areas of oil recovery and exploitation. Bioremediation by indigenous plants in cooperation with hydrocarbon degrading microorganisms is an economically and ecologically feasible means to reclaim contaminated soils. To study the effects of indigenous soil bacteria capable of utilizing oil hydrocarbons on biomass production of plants growing in oil-contaminated soils eight bacterial strains were isolated from contaminated soils in Kazakhstan and characterized for their abilities to degrade oil components. Four of them, identified as species of Gordonia and Rhodococcus turned out to be effective degraders. They produced a variety of organic acids from oil components, of which 59 were identified and 7 of them are hitherto unknown acidic oil metabolites. One of them, Rhodococcus erythropolis SBUG 2054, utilized more than 140 oil components. Inoculating barley seeds together with different combinations of these bacterial strains restored normal growth of the plants on contaminated soils, demonstrating the power of this approach for bioremediation. Furthermore, we suggest that the plant promoting effect of these bacteria is not only due to the elimination of toxic oil hydrocarbons but possibly also to the accumulation of a variety of organic acids which modulate the barley's rhizosphere environment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study area evaluations. Volume 6-H. North plants study area exposure assessment version 4. 1. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The objectives of the Human Health Exposure Assessment include: (1) estimate the type and magnitude of exposures to contaminants; (2) Identify contaminants of concern; (3) Identify sites for remedial action; (4) Recommend sites for the no action remedial alternative; and (5) Provide a basis for detailed characterization of the risk associated with all sites. This document consists of the following: An executive summary. Vol I - Land use and exposed population evaluations. Vol. II III - Toxicity assessment (includes army and shell toxicity profiles). Vol. IV - PPLV Methodology. Vol. V - PPLV Calculations. Vol. VI - Study area exposuremore » analysis A introduction, B Western study ares, C Southern study area, D northern Central study area, E Central study area, F Eastern study area, G South plants study area, and H North plants study area. Vol. VII - Summary exposure assessment.« less

Hydrological character of the soil of a degraded area: comparison of analysis physical, chemical and floristic vegetational

NASA Astrophysics Data System (ADS)

Manfredi, Paolo; Cassinari, Chiara; Giupponi, Luca; Sichel, Giorgio Maria; Trevisan, Marco

2013-04-01

Extractor (Piastre di Richards): were carried out from water retention curves and calculated the values of percolating water (water circulation) and the useful water (maximum available water) were also determined physical and chemical parameters that most affect the hydrological characteristics of the soil such as texture, organic carbon, salinity and total limestone. The same soils were subjected to a floristic and vegetational analysis with relative comparison of the biological spectrum of the site with the spectra of other territories taken in comparison (Piacenza, Emilia Romagna, northern Italy, southern Italy). The 40% of the plants of the area is represented by Therophytes, species that are adapted to live in environments disturbed by human activities or climate. The high frequency of this species does not seem motivated either by the ombrothermic diagram elaborated with the help of the climatic data of the meteorological station of Piacenza, which was observed for a brief period the appearance of water deficit, neither linked to the interference from human activities which turns out to be low. Keywords: degraded soils, hydrological character, floristic vegetation analysis

Planting aspen to rehabilitate riparian areas: a pilot study

Treesearch

Wayne D. Shepperd; Stephen A. Mata

2005-01-01

We planted 742 greenhouse-grown containerized aspen seedlings in the riparian area of Hurd Creek on the Arapaho National Forest east of Tabernash, Colorado. Objectives were to (1) determine whether aspen seedlings can be planted in an operational setting and survive in sufficient numbers to successfully establish a mature aspen stand and (2) determine the effectiveness...

Abandoned seasonal livestock migration reflected by plant functional traits: A case study in Kyrgyz rangelands

NASA Astrophysics Data System (ADS)

Hoppe, Franziska; Zhusui Kyzy, Taalaigul; Usupbaev, Adilet; Schickoff, Udo

2017-04-01

At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basis to sustain people's livelihoods, rangeland degradation presents a threat for the majority of the population. Recently, the usage of plant functional traits as a powerful tool for the characterization of vegetation dynamics in response to anthropogenic and natural disturbances has been put forward. Grazing is one of the most severe disturbances on vegetation, which concerns equally the loss of area and biomass. Because grazing is both depending on and affecting plant functional traits, important insights can be generated, based on this codependency. We hypothesized that the contrasting grazing intensity of summer and winter pastures is reflected by the chosen traits. We used traits such as plant height, flowering start, growth form as well as SLA (Specific Leaf Area) and LMA (Leaf Mass per Area). Based on former phytosociological classification of the main pasture types (summer and winter pastures), community structure and the traits of dominant plant species were analyzed. Our results showed that on winter pastures grazing decreased plant height and SLA and favored plants with an earlier flowering start as well as rosette plants and ascending plants. We conclude that the study of trait composition in relation to anthropogenic disturbances can provide important insights into the mechanism of plant response to grazing in high-altitude rangelands.

Regulation of Leaf Starch Degradation by Abscisic Acid Is Important for Osmotic Stress Tolerance in Plants[OPEN

PubMed Central

Thalmann, Matthias; Pazmino, Diana; Seung, David; Horrer, Daniel; Nigro, Arianna; Meier, Tiago; Zeeman, Samuel C.; Santelia, Diana

2016-01-01

Starch serves functions that range over a timescale of minutes to years, according to the cell type from which it is derived. In guard cells, starch is rapidly mobilized by the synergistic action of β-AMYLASE1 (BAM1) and α-AMYLASE3 (AMY3) to promote stomatal opening. In the leaves, starch typically accumulates gradually during the day and is degraded at night by BAM3 to support heterotrophic metabolism. During osmotic stress, starch is degraded in the light by stress-activated BAM1 to release sugar and sugar-derived osmolytes. Here, we report that AMY3 is also involved in stress-induced starch degradation. Recently isolated Arabidopsis thaliana amy3 bam1 double mutants are hypersensitive to osmotic stress, showing impaired root growth. amy3 bam1 plants close their stomata under osmotic stress at similar rates as the wild type but fail to mobilize starch in the leaves. 14C labeling showed that amy3 bam1 plants have reduced carbon export to the root, affecting osmolyte accumulation and root growth during stress. Using genetic approaches, we further demonstrate that abscisic acid controls the activity of BAM1 and AMY3 in leaves under osmotic stress through the AREB/ABF-SnRK2 kinase-signaling pathway. We propose that differential regulation and isoform subfunctionalization define starch-adaptive plasticity, ensuring an optimal carbon supply for continued growth under an ever-changing environment. PMID:27436713

[Assessment of soil degradation in regions of nuclear power explosions at Semipalatinsk Nuclear Test Site].

PubMed

Evseeva, T I; Geras'kin, S A; Maĭstrenko, T A; Belykh, E S

2011-01-01

Degree of the soil cover degradation at the "Balapan" and "Experimental field" test sites was assessed based on Allium-test of soil toxicity results and international guidelines on radioactive restriction of solid materials (IAEA, 2004) and environment (Smith, 2005). Soil cover degradation maps of large-scale (1 : 25000) were made. The main part of the area mapped belongs to high-contaminated toxic degraded soil. A relationship between the soil toxicity and the total radionuclide activity concentrations was found to be described by power functions. When the calculated value (equal to 413-415 Bq/kg of air dry soil) increases, the soil becomes toxic for plants. This value is 7.8 times higher than the maximal value for background territories (53 Bq/kg) surrounding SNTS. Russian sanitary and hygienic guidelines (Radiation safety norms, 2009; Sanitary regulations of radioactive waste management, 2003) underestimate the degree of soil radioactive contamination for plants.

Review: Endoplasmic Reticulum-Associated Degradation (ERAD)-Dependent Control of (Tri)terpenoid Metabolism in Plants.

PubMed

Erffelinck, Marie-Laure; Goossens, Alain

2018-06-15

Plants are sessile organisms. Therefore, they developed the capacity to quickly respond to biotic and abiotic environmental stresses, for instance by producing a broad spectrum of bioactive specialized metabolites. In this defense response, the jasmonate phytohormones can instigate a signaling cascade that leads to the specific elicitation and reprograming of numerous metabolic pathways. Recent research progress has provided several insights into the regulatory networks of many specialized metabolic pathways, mainly at the transcriptional level. Nonetheless, our view on the regulation of defense metabolism remains far from comprehensive. Here, we describe the recent advances obtained with regard to one aspect of the regulation of plant specialized metabolism, namely the posttranslational regulation of enzyme stability. We focus on terpenoid biosynthesis and in particular on the rate-limiting and well-investigated enzyme of the terpenoid precursor pathway, 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR). There are clear similarities, as well as important mechanistic differences, among the components involved in the posttranslational regulation of terpenoid biosynthesis via HMGR in plants, yeasts, and mammals. Furthermore, in plants, several of these components evolved to respond to specific signaling cues. Indeed, the elements of the plant endoplasmic reticulum-associated degradation (ERAD) and ER stress-associated processes can be induced upon environmental stresses and during specific developmental processes, thereby allowing a unique posttranslational regulation of terpenoid biosynthesis pathways. Georg Thieme Verlag KG Stuttgart · New York.

Sodium accumulation at potential-induced degradation shunted areas in polycrystalline silicon modules

DOE PAGES

Harvey, Steven P.; Aguiar, Jeffery A.; Hacke, Peter; ...

2016-09-19

Here, we investigated potential-induced degradation (PID) in silicon mini-modules that were subjected to accelerated stressing to induce PID conditions. Shunted areas on the cells were identified with photoluminescence and dark lock-in thermography (DLIT) imaging. The identical shunted areas were then analyzed via time-of-flight secondary-ion mass spectrometry (TOFSIMS) imaging, 3-D tomography, and high-resolution transmission electron microscopy. The TOF-SIMS imaging indicates a high concentration of sodium in the shunted areas, and 3-D tomography reveals that the sodium extends more than 2 um from the surface below shunted regions. Transmission electron microscopy investigation reveals that a stacking fault is present at an areamore » identified as shunted by DLIT imaging. After the removal of surface sodium, tomography reveals persistent sodium present around the junction depth of 300 nm and a drastic difference in sodium content at the junction when comparing shunted and nonshunted regions.« less

AN EARLY STAGE IN THE PLANT RECOLONIZATION OF A NUCLEAR TARGET AREA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rickard, W.H.; Shields, L.M.

1963-01-01

Vegetational analyses were conducted three years postdetonation in a nuclear target area in a Grayia spinosa-Lycium andersonii community in Yucca Fiat, Nevada. Annual plants dominated the early stage of recolonization and were quantitatively more abundant in the disturbed areas than in an adjacent undisturbed shrub community. Ment zelia albicaulis and Chaenactis steviodes occurred in both disturbed and undisturbed areas, however; Mentzelia was more abundant in disturbed areas while Chaenactis was more abundant in the undisturbed community. Salsola kali was confined to disturbed areas while Phacelia vallismortae was more often encountered in the undisturbed community. The plant recolonization of a mechanicallymore » disturbed area was quantitatively and qualitatively more like that of the interior zone of the nuclear target area than less disturbed habitats. These data support a conclusion that soil displacement presents a more rigorous habitat for plant recolonization than disturbances created by the wider ranging destructive components of a nuclear detonation. (auth)« less

Poverty, population and environmental degradation in China.

PubMed

Rozelle, S; Huang, J; Zhang, L

1997-06-01

This article examines the relationship between poverty, population, and environmental degradation in China. Environmental conditions include water pollution, deforestation, destruction of grasslands, soil erosion, and salinization. The authors review China's success in controlling environmental degradation through leadership, environmental policies, and institutional capacity. Findings suggest that environmental progress is best achieved indirectly by poverty alleviation, market integration, and population control. Government policies were not very effective. Degradation occurs due to limited financial resources, poorly trained personnel, and political factors. Control of water pollution was instituted since the 1980s. The levels of pollutants have been reduced, but the type of pollutant determines the seriousness of impact. Water pollution is due to industrial wastes, agricultural run-off, and soil erosion. Since the 1970s, reforestation targets have not been met. Technical extension and monitoring of planting is not available in most areas, and private, profit seeking interests control acreage. Grassland destruction is due to deforestation, agricultural expansion, and overgrazing. Independent regional authorities have successfully managed pasture programs. Erosion is the most serious in Loess Plateau, the Red Soils area, the Northeast China Plain, and the Northwest Grasslands, which comprise 70% of total land area. In 1990, erosion control was practiced in 39% of eroded land area. Salinization has remained fairly constant. Environmental controls (direct regulation, planned recovery, and state-mandated technological improvements) are uneven. The main tool for environmental management is the State Environmental Protection Commission and its executive unit, SEPA. Problems stem from vague laws, lack of means of enforcement, lack of coordination of laws, and lack of standards, schedules, and other provisions in ordinances.

Phosphorus, carbon- and nitrogen interactions in productive and degraded tropical pastures

NASA Astrophysics Data System (ADS)

Oberson, A.; Hegglin, D. D.; Nesper, M.; Rao, I.; Fonte, S.; Ramirez, B.; Velasquez, J.; Tamburini, F.; Bünemann, E. K.; Frossard, E.

2011-12-01

Pastures are the main land use in deforested areas of tropical South America. The highly weathered soils of these regions usually have low total and available phosphorus (P) contents. Low P availability can strongly limit plant and animal productivity and other soil ecosystem functions. Most introduced pastures of Brachiaria spp. are grass-alone (GA) while some are grass-legume (GL) pastures. The majority of the introduced pastures, particularly the grass-alone are at some state of degradation (GD). Pasture degradation induces severe loss of plant biomass production, with drastic ecological and economic implications. Although the importance of P deficiency in pasture degradation has been recognized, the knowledge generated on stoichiometry of carbon (C), nitrogen (N) and P along pathways of the nutrient cycles of pastures, with different botanical composition and productivity, has been very limited. We will present results of a case study realized during 2010 to 2011 in the forest margins agro-ecosystem of the department of Caquetá, Colombia. Our objectives were to determine: i) whether P availability is lower in degraded compared to productive pastures, and ii) whether the introduction of legumes in the pasture increases P availability through enhanced biological P cycling through plant growth, plant litter decomposition and the soil microbial biomass; and iii) whether pasture types (GA vs GL) and the state of pasture degradation affect the C:N:P ratios in nutrient pools of the soil-plant system. An on-farm study was conducted on nine farms in the department of Caquetá, Colombia. On every farm three different pasture types were studied: degraded grass alone pastures (GD), productive grass-alone pastures (GA) and productive grass-legume pastures (GL). Basic soil characteristics and indicators on soil P status, microbial P cycling, plant biomass production, plant litter deposition and nutrient concentrations in plant tissue were determined. Analysis of P, C and N

[Screening of harmine tolerance/degrading bacteria from camel rumen].

PubMed

An, Dengdi; Zhu, Yanlei; Tang, Jing; Ye, Yongxia; Zeng, Xianchun

2010-08-01

Peganum harmala, a famous traditional Chinese drug, contains a variety of alkaloids and toxic for many animals. Camels mainly live in desert or semi-desert areas, with the robust gastrointestine system in digesting various feed including toxic plants without disease symptoms. Camel rumen content was used as the inoculant to inoculate medium M98-5 which contains 100 mg x L(-1) harmin and cultivated for 5 days. Upto 5 subculturings, strains that could degrading or tolerant harmine were isolated. Their conversion activity was determined by thin-layer chromatography. The taxonomic position of the strains were identified based on 16S rRNA sequences analysis. 15 out of the 29 isolates have harmine degrading activity. Most of the isolates are identified as the members of the Genera Lactobacillus (16 strains, 55%), Shigella (7 strains, 24%) and Bacillus (4 strains, 13.8%). Only one strain belong to genus Enterococcus and one belong to genus Megasphaera. The results indicated that the harmine tolerance/degrading communities of camel rumen are limited and only Lactobacillus have harmine-degrading activity.

Production of plant cell wall degrading enzymes by monoculture and co-culture of Aspergillus niger and Aspergillus terreus under SSF of banana peels.

PubMed

Rehman, Shazia; Aslam, Hina; Ahmad, Aqeel; Khan, Shakeel Ahmed; Sohail, Muhammad

2014-01-01

Filamentous fungi are considered to be the most important group of microorganisms for the production of plant cell wall degrading enzymes (CWDE), in solid state fermentations. In this study, two fungal strains Aspergillus niger MS23 and Aspergillus terreus MS105 were screened for plant CWDE such as amylase, pectinase, xylanase and cellulases (β-glucosidase, endoglucanase and filterpaperase) using a novel substrate, Banana Peels (BP) for SSF process. This is the first study, to the best of our knowledge, to use BP as SSF substrate for plant CWDE production by co-culture of fungal strains. The titers of pectinase were significantly improved in co-culture compared to mono-culture. Furthermore, the enzyme preparations obtained from monoculture and co-culture were used to study the hydrolysis of BP along with some crude and purified substrates. It was observed that the enzymatic hydrolysis of different crude and purified substrates accomplished after 26 h of incubation, where pectin was maximally hydrolyzed by the enzyme preparations of mono and co-culture. Along with purified substrates, crude materials were also proved to be efficiently degraded by the cocktail of the CWDE. These results demonstrated that banana peels may be a potential substrate in solid-state fermentation for the production of plant cell wall degrading enzymes to be used for improving various biotechnological and industrial processes.

Production of plant cell wall degrading enzymes by monoculture and co-culture of Aspergillus niger and Aspergillus terreus under SSF of banana peels

PubMed Central

Rehman, Shazia; Aslam, Hina; Ahmad, Aqeel; Khan, Shakeel Ahmed; Sohail, Muhammad

2014-01-01

Filamentous fungi are considered to be the most important group of microorganisms for the production of plant cell wall degrading enzymes (CWDE), in solid state fermentations. In this study, two fungal strains Aspergillus niger MS23 and Aspergillus terreus MS105 were screened for plant CWDE such as amylase, pectinase, xylanase and cellulases (β-glucosidase, endoglucanase and filterpaperase) using a novel substrate, Banana Peels (BP) for SSF process. This is the first study, to the best of our knowledge, to use BP as SSF substrate for plant CWDE production by co-culture of fungal strains. The titers of pectinase were significantly improved in co-culture compared to mono-culture. Furthermore, the enzyme preparations obtained from monoculture and co-culture were used to study the hydrolysis of BP along with some crude and purified substrates. It was observed that the enzymatic hydrolysis of different crude and purified substrates accomplished after 26 h of incubation, where pectin was maximally hydrolyzed by the enzyme preparations of mono and co-culture. Along with purified substrates, crude materials were also proved to be efficiently degraded by the cocktail of the CWDE. These results demonstrated that banana peels may be a potential substrate in solid-state fermentation for the production of plant cell wall degrading enzymes to be used for improving various biotechnological and industrial processes. PMID:25763058

Treatment of municipal wastewater treatment plant effluents with modified photo-Fenton as a tertiary treatment for the degradation of micro pollutants and disinfection.

PubMed

Klamerth, Nikolaus; Malato, Sixto; Agüera, Ana; Fernández-Alba, Amadeo; Mailhot, Gilles

2012-03-06

The goal of this paper was to develop a modified photo-Fenton treatment able to degrade micro pollutants in municipal wastewater treatment plant (MWTP) effluents at a neutral pH with minimal iron and H(2)O(2) concentrations. Complexation of Fe by ethylenediamine-N,N'-disuccinic acid (EDDS) leads to stabilization and solubilization of Fe at natural pH. Photo-Fenton experiments were performed in a pilot compound parabolic collector (CPC) solar plant. Samples were treated with solid phase extraction (SPE) and analyzed by HPLC-Qtrap-MS. The rapid degradation of contaminants within the first minutes of illumination and the low detrimental impact on degradation of bicarbonates present in the water suggested that radical species other than HO(•) are responsible for the efficiency of such photo-Fenton process. Disinfection of MWTP effluents by the same process showed promising results, although disinfection was not complete.

Enhancement of Micropollutant Degradation at the Outlet of Small Wastewater Treatment Plants

PubMed Central

Rossi, Luca; Queloz, Pierre; Brovelli, Alessandro; Margot, Jonas; Barry, D. A.

2013-01-01

The aim of this work was to evaluate low-cost and easy-to-operate engineering solutions that can be added as a polishing step to small wastewater treatment plants to reduce the micropollutant load to water bodies. The proposed design combines a sand filter/constructed wetland with additional and more advanced treatment technologies (UV degradation, enhanced adsorption to the solid phase, e.g., an engineered substrate) to increase the elimination of recalcitrant compounds. The removal of five micropollutants with different physico-chemical characteristics (three pharmaceuticals: diclofenac, carbamazepine, sulfamethoxazole, one pesticide: mecoprop, and one corrosion inhibitor: benzotriazole) was studied to evaluate the feasibility of the proposed system. Separate batch experiments were conducted to assess the removal efficiency of UV degradation and adsorption. The efficiency of each individual process was substance-specific. No process was effective on all the compounds tested, although elimination rates over 80% using light expanded clay aggregate (an engineered material) were observed. A laboratory-scale flow-through setup was used to evaluate interactions when removal processes were combined. Four of the studied compounds were partially eliminated, with poor removal of the fifth (benzotriazole). The energy requirements for a field-scale installation were estimated to be the same order of magnitude as those of ozonation and powdered activated carbon treatments. PMID:23484055

Ethnobotanical investigation on medicinal plants in Algoz area (South Kordofan), Sudan.

PubMed

Issa, Tahani Osman; Mohamed, Yahya Sulieman; Yagi, Sakina; Ahmed, Reem Hassan; Najeeb, Telal Mohammed; Makhawi, Abdelrafie Mohamed; Khider, Tarig Osman

2018-04-27

The inhabitants of western Sudan use traditional medicine for the treatment of various ailments due to lack of medical doctors and unaffordable prices of pharmaceutical products. The present study is the first documentation of the traditional plant knowledge on medicinal uses of plants by healers in Algoz (South Kordofan), Sudan. Ethnobotanical data were collected over a period from March to November 2015 using semi-structured interviews with 30 healers (24 male and 6 female) living in the investigated area. Quantitative indices such as use categories, use value (UV) and informant consensus factor (ICF) were intended to evaluate the importance of medicinal plant species. A total of 94 medicinal plants, which belong to 45 families and 81 genera, were recorded in the study area. The most represented families are Leguminosae with 20 species followed by Combretaceae (6 species), Rubiaceae (5 species) and Asteraceae (4 species). The reported species were belonging to herbs (43%), trees (28%), shrubs (22%), climbers (4%) and parasites (3%). Root and stem (21% each) were the most plant parts used. A majority of remedies are administered orally (67%) where infusion (36%) and maceration (32%) are the most used methods. The highest ICF (0.87) was reported for poisonous animal bites followed by urinary system diseases (0.89), blood system disorders (0.88) and gynaecological diseases (0.87). Anastatica hierochuntica, Ctenolepis cerasiformis, Echinops longifolius, Cleome gynandra, Maerua pseudopetalosa, Martynia annua, Oldenlandia uniflora, Opuntia ficus-indica, Solanum dubium, Sonchus cornutus, Tribulus terrestris and Drimia maritima were reported for the first time in this study. The number of medicinal plants reported in this paper reflects evidence that Algoz area had a high diversity of medicinal plants which will continue to play an important role in the healthcare system in the study area.

26+ Year Old Photovoltaic Power Plant: Degradation and Reliability Evaluation of Crystalline Silicon Modules -- South Array

NASA Astrophysics Data System (ADS)

Olakonu, Kolapo

As the use of photovoltaic (PV) modules in large power plants continues to increase globally, more studies on degradation, reliability, failure modes, and mechanisms of field aged modules are needed to predict module life expectancy based on accelerated lifetime testing of PV modules. In this work, a 26+ year old PV power plant in Phoenix, Arizona has been evaluated for performance, reliability, and durability. The PV power plant, called Solar One, is owned and operated by John F. Long's homeowners association. It is a 200 kW dc, standard test conditions (STC) rated power plant comprised of 4000 PV modules or frameless laminates, in 100 panel groups (rated at 175 kW ac). The power plant is made of two center-tapped bipolar arrays, the north array and the south array. Due to a limited time frame to execute this large project, this work was performed by two masters students (Jonathan Belmont and Kolapo Olakonu) and the test results are presented in two masters theses. This thesis presents the results obtained on the south array and the other thesis presents the results obtained on the north array. Each of these two arrays is made of four sub arrays, the east sub arrays (positive and negative polarities) and the west sub arrays (positive and negative polarities), making up eight sub arrays. The evaluation and analyses of the power plant included in this thesis consists of: visual inspection, electrical performance measurements, and infrared thermography. A possible presence of potential induced degradation (PID) due to potential difference between ground and strings was also investigated. Some installation practices were also studied and found to contribute to the power loss observed in this investigation. The power output measured in 2011 for all eight sub arrays at STC is approximately 76 kWdc and represents a power loss of 62% (from 200 kW to 76 kW) over 26+ years. The 2011 measured power output for the four south sub arrays at STC is 39 kWdc and represents a power

Starch-enhanced degradation of HMW PAHs by Fusarium sp. in an aged polluted soil from a coal mining area.

PubMed

Zhao, Ou-Ya; Zhang, Xue-Na; Feng, Sheng-Dong; Zhang, Li-Xiu; Shi, Wei; Yang, Zhi-Xin; Chen, Miao-Miao; Fang, Xue-Dan

2017-05-01

The present study used strain ZH-H2 (Fusarium sp.) isolated by our group as the PAH-degrading strain and 5-6-rings PAHs as degradation objects. The soil incubation experiment was carried out to investigate the starch-enhanced degradation effects of HMW PAHs by Fusarium sp. in an Aged Polluted Soil from a Coal Mining Area. The results showed that the removal rates of BaP, InP and BghiP increased with increasing inoculation rate of ZH-H2 in the unsterile aged polluted soil of coal mining area, with the exception of BbF degradation which increased in the H2 treatment and then decreased. Different addition dosage of starch apparently resulted in degradation of 4 PAHs in soil, with removal rates of 14.47% for BaP, 23.83% for DbA, 30.77% for BghiP and 31.00% for InP obtained with treatment D2, respectively higher than in treatment D1. So starch addition apparently enhanced the degradation of the 4 PAHs, especially InP and BghiP, by native microbes in the aged HMW PAH-polluted soil. By adding starch to these aged polluted soils with inoculated strain ZH-H2, HMW-PAHs degradation was further improved and addition of 0.5 g kg -1 starch to soils with 1.0 g kg -1 Fusarium ZH-H2 (D 2  + H 2 ) performed best to the 4 HMW-PAHs in all of these combination treatments by a factor of up to 3.09, depending on the PAH. We found that the highest polyphenol oxidase activities under D 2  + H 2 treatments are consistent with the results of removal rates of 4 PAHs. Our findings suggest that the combination of Fusarium sp. ZH-H2 and starch offers a suitable alternative for bioremediation of aged PAH-contaminated soil in coal mining areas, with a recommended inoculation size of 0.5 g Fusarium sp. ZH-H2 and addition of 0.5 g kg -1 starch per kg soil. Copyright © 2016. Published by Elsevier Ltd.

Efficient degradation of lignocellulosic plant biomass without pretreatment by the 9 thermophilic anaerobe, Anaerocellum thermophilum DSM 6725

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Sung-Jae; Kataeva, Irina; Hamilton-Brehm, Scott

2009-01-01

Very few cultivated microorganisms can degrade lignocellulosic biomass without chemical pretreatment. We show here that 'Anaerocellum thermophilum' DSM 6725, an anaerobic bacterium that grows optimally at 75 C, efficiently utilizes various types of untreated plant biomass, as well as crystalline cellulose and xylan. These include hardwoods such as poplar, low-lignin grasses such as napier and Bermuda grasses, and high-lignin grasses such as switchgrass. The organism did not utilize only the soluble fraction of the untreated biomass, since insoluble plant biomass (as well as cellulose and xylan) obtained after washing at 75 C for 18 h also served as a growthmore » substrate. The predominant end products from all growth substrates were hydrogen, acetate, and lactate. Glucose and cellobiose (on crystalline cellulose) and xylose and xylobiose (on xylan) also accumulated in the growth media during growth on the defined substrates but not during growth on the plant biomass. A. thermophilum DSM 6725 grew well on first- and second-spent biomass derived from poplar and switchgrass, where spent biomass is defined as the insoluble growth substrate recovered after the organism has reached late stationary phase. No evidence was found for the direct attachment of A. thermophilum DSM 6725 to the plant biomass. This organism differs from the closely related strain A. thermophilum Z-1320 in its ability to grow on xylose and pectin. Caldicellulosiruptor saccharolyticus DSM 8903 (optimum growth temperature, 70 C), a close relative of A. thermophilum DSM 6725, grew well on switchgrass but not on poplar, indicating a significant difference in the biomass-degrading abilities of these two otherwise very similar organisms.« less

Assessing degradation of abandoned farmlands for conservation of the Monte Desert biome in Argentina.

PubMed

Yannelli, Florencia A; Tabeni, Solana; Mastrantonio, Leandro E; Vezzani, Nazareth

2014-01-01

Land abandonment is a major issue worldwide. In Argentina, the Monte Desert is the most arid rangeland, where the traditional conservation practices are based on successional management of areas excluded to disturbances or abandoned. Some areas subjected to this kind of management may be too degraded, and thus require active restoration. Therefore, the aim of this study was to assess whether passive succession-based management is a suitable approach by evaluating the status of land degradation in a protected area after 17-41 years of farming abandonment. Soil traits and plant growth forms were quantified and compared between sites according to time since abandonment and former land use (cultivation and grazing). Two variables were calculated using the CORINE-CEC method, i.e., potential (PSER) and actual (ASER) soil erosion risk. PSER indicates the erosion risk when no vegetation is present, while ASER includes the protective role of vegetation cover. Results showed that land use history had no significant effect on plant growth forms or soil traits (p > 0.05). After more than 25 years since abandonment of farming activities, soil conditions and vegetation cover had improved, thus having a lower ASER. Nevertheless, the present soil physical crusts may have delayed the full development of vegetation, enhancing erosion processes. Overall, this study indicates that succession-based management may not be the best practice in terms of conservation. Therefore, any effort for conservation in the Monte Desert should contemplate the current status of land degradation and potential vegetation recovery.

Lignin degradation by selected fungal species.

PubMed

Knežević, Aleksandar; Milovanović, Ivan; Stajić, Mirjana; Lončar, Nikola; Brčeski, Ilija; Vukojević, Jelena; Cilerdžić, Jasmina

2013-06-01

As biological decomposition of plant biomass represents a popular alternative environmental-friendly and economically justified process, screening of ligninolytic enzyme systems of various fungal species is a topical study area. The goal of the study was to obtain clear insight into the dynamics of laccase, Mn-dependent peroxidase, and Mn-independent peroxidase activity and levels of wheat straw lignin degradation in seven wood-rotting fungi. The best laccase producers were Pleurotus ostreatus and Pleurotus eryngii. Lenzites betulinus and Fomitopsis pinicola were the best Mn-dependent peroxidase producers, and P. ostreatus the weakest one. The peak of Mn-independent peroxidase was noted in Dichomytus squalens, and the minimum value in P. ostreatus. The profiles of the three enzymes, obtained by isoelectric focusing, were variable depending on the species and cultivation period. D. squalens was the best lignin degrader (34.1% of total lignin amount), and P. ostreatus and P. eryngii the weakest ones (7.1% and 14.5%, respectively). Copyright © 2013 Elsevier Ltd. All rights reserved.

Potential of the TCE-degrading endophyte Pseudomonas putida W619-TCE to improve plant growth and reduce TCE phytotoxicity and evapotranspiration in poplar cuttings.

PubMed

Weyens, Nele; Truyens, Sascha; Dupae, Joke; Newman, Lee; Taghavi, Safiyh; van der Lelie, Daniel; Carleer, Robert; Vangronsveld, Jaco

2010-09-01

The TCE-degrading poplar endophyte Pseudomonas putida W619-TCE was inoculated in poplar cuttings, exposed to 0, 200 and 400 mg l(-1) TCE, that were grown in two different experimental setups. During a short-term experiment, plants were grown hydroponically in half strength Hoagland nutrient solution and exposed to TCE for 3 days. Inoculation with P. putida W619-TCE promoted plant growth, reduced TCE phytotoxicity and reduced the amount of TCE present in the leaves. During a mid-term experiment, plants were grown in potting soil and exposed to TCE for 3 weeks. Here, inoculation with P. putida W619-TCE had a less pronounced positive effect on plant growth and TCE phytotoxicity, but resulted in strongly reduced amounts of TCE in leaves and roots of plants exposed to 400 mg l(-1) TCE, accompanied by a lowered evapotranspiration of TCE. Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), which are known intermediates of TCE degradation, were not detected. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Using American elm in mixed-species plantings to restore above- and below-ground function to degraded riparian buffers

Treesearch

C.C. Pinchot; D.J. Lodge; R. Minocha; T.W. Noon; V. D’Amico; C. Flower; K.M. Knight; J. Slavicek

2017-01-01

We recently established a study to evaluate the effects of several riparian restoration treatments on degraded streambanks located on the Finger Lakes National Forest (FLNF) in western New York. A legacy of cattle grazing has led to soil compaction, invasion by non-native invasive plant species (NNIP), as well as heavy nitrogen loading and increased bacterial levels in...

Uptake, degradation and chiral discrimination of N-acyl-D/L-homoserine lactones by barley (Hordeum vulgare) and yam bean (Pachyrhizus erosus) plants.

PubMed

Götz, Christine; Fekete, Agnes; Gebefuegi, Istvan; Forczek, Sándor T; Fuksová, Kvetoslava; Li, Xiaojing; Englmann, Matthias; Gryndler, Milan; Hartmann, Anton; Matucha, Miroslav; Schmitt-Kopplin, Philippe; Schröder, Peter

2007-11-01

Bacterial intraspecies and interspecies communication in the rhizosphere is mediated by diffusible signal molecules. Many Gram-negative bacteria use N-acyl-homoserine lactones (AHLs) as autoinducers in the quorum sensing response. While bacterial signalling is well described, the fate of AHLs in contact with plants is much less known. Thus, adsorption, uptake and translocation of N-hexanoyl- (C6-HSL), N-octanoyl- (C8-HSL) and N-decanoyl-homoserine lactone (C10-HSL) were studied in axenic systems with barley (Hordeum vulgare L.) and the legume yam bean (Pachyrhizus erosus (L.) Urban) as model plants using ultra-performance liquid chromatography (UPLC), Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and tritium-labelled AHLs. Decreases in AHL concentration due to abiotic adsorption or degradation were tolerable under the experimental conditions. The presence of plants enhanced AHL decline in media depending on the compounds' lipophilicity, whereby the legume caused stronger AHL decrease than barley. All tested AHLs were traceable in root extracts of both plants. While all AHLs except C10-HSL were detectable in barley shoots, only C6-HSL was found in shoots of yam bean. Furthermore, tritium-labelled AHLs were used to determine short-term uptake kinetics. Chiral separation by GC-MS revealed that both plants discriminated D-AHL stereoisomers to different extents. These results indicate substantial differences in uptake and degradation of different AHLs in the plants tested.

Proteolytic activity during senescence of plants

NASA Technical Reports Server (NTRS)

Huffaker, R. C.

1990-01-01

degradation. This field of study has great practical implications, e.g. maintaining photosynthesis during seed-fill in order to obtain greater crop yields. The current use of stay green' variants in the populations of several crop plants to produce increased yields shows the potential for future development. The near future should see exciting discoveries in these areas of research that will have far reaching effects on the construction of transgenic plants for future research accomplishments and agricultural use.

Investigating the control of chlorophyll degradation by genomic correlation mining

USDA-ARS?s Scientific Manuscript database

Chlorophyll degradation is an intricate process that is critical in a variety of plant tissues at different times during the plant life cycle. Many of the photoactive chlorophyll degradation intermediates are exceptionally cytotoxic necessitating that the pathway be carefully coordinated and regulat...

Methods of saccharification of polysaccharides in plants

DOEpatents

Howard, John; Fake, Gina

2014-04-29

Saccharification of polysaccharides of plants is provided, where release of fermentable sugars from cellulose is obtained by adding plant tissue composition. Production of glucose is obtained without the need to add additional .beta.-glucosidase. Adding plant tissue composition to a process using a cellulose degrading composition to degrade cellulose results in an increase in the production of fermentable sugars compared to a process in which plant tissue composition is not added. Using plant tissue composition in a process using a cellulose degrading enzyme composition to degrade cellulose results in decrease in the amount of cellulose degrading enzyme composition or exogenously applied cellulase required to produce fermentable sugars.

Predicting parameters of degradation succession processes of Tibetan Kobresia grasslands

NASA Astrophysics Data System (ADS)

Lin, L.; Li, Y. K.; Xu, X. L.; Zhang, F. W.; Du, Y. G.; Liu, S. L.; Guo, X. W.; Cao, G. M.

2015-08-01

In the past two decades, increasing human activity (i.e., overgrazing) in the Tibetan Plateau has strongly influenced plant succession processes, resulting in the degradation of alpine grasslands. Therefore, it is necessary to diagnose the degree of degradation to enable implementation of appropriate management for sustainable exploitation and protection of alpine grasslands. Here, we investigated environmental factors and plant functional group quantity factors (PFGs) during the alpine grassland succession processes. Principal component analysis (PCA) was used to identify the parameters indicative of degradation. We divided the entire degradation process into six stages. PFG types shifted from rhizome bunch grasses to rhizome plexus and dense plexus grasses during the degradation process. Leguminosae and Gramineae plants were replaced by Sedges during the advanced stages of degradation. The PFGs were classified into two reaction groups: the grazing-sensitive group, containing Kobresia humilis Mey, and Gramineae and Leguminosae plants, and the grazing-insensitive group, containing Kobresia pygmaea Clarke. The first group was correlated with live root biomass in the surface soil (0-10 cm), whereas the second group was strongly correlated with mattic epipedon thickness and K. pygmaea characteristics. The degree of degradation of alpine meadows may be delineated by development of mattic epipedon and PFG composition. Thus, meadows could be easily graded and their use adjusted based on our scaling system, which would help prevent irreversible degradation of important grasslands. Because relatively few environmental factors are investigated, this approach can save time and labor to formulate a conservation management plan for degraded alpine meadows.

Predicting parameters of degradation succession processes of Tibetan Kobresia grasslands

NASA Astrophysics Data System (ADS)

Lin, L.; Li, Y. K.; Xu, X. L.; Zhang, F. W.; Du, Y. G.; Liu, S. L.; Guo, X. W.; Cao, G. M.

2015-11-01

In the past two decades, increasing human activity (i.e., overgrazing) in the Tibetan Plateau has strongly influenced plant succession processes, resulting in the degradation of alpine grasslands. Therefore, it is necessary to diagnose the degree of degradation to enable implementation of appropriate management for sustainable exploitation and protection of alpine grasslands. Here, we investigated environmental factors and plant functional group (PFG) quantity factors during the alpine grassland succession processes. Principal component analysis (PCA) was used to identify the parameters indicative of degradation. We divided the entire degradation process into six stages. PFG types shifted from rhizome bunchgrasses to rhizome plexus and dense-plexus grasses during the degradation process. Leguminosae and Gramineae plants were replaced by sedges during the advanced stages of degradation. The PFGs were classified into two reaction groups: the grazing-sensitive group, containing Kobresia humilis Mey, and Gramineae and Leguminosae plants, and the grazing-insensitive group, containing Kobresia pygmaea Clarke. The first group was correlated with live root biomass in the surface soil (0-10 cm), whereas the second group was strongly correlated with mattic epipedon thickness and K. pygmaea characteristics. The degree of degradation of alpine meadows may be delineated by development of mattic epipedon and PFG composition. Thus, meadows could be easily graded and their use adjusted based on our scaling system, which would help prevent irreversible degradation of important grasslands. Because relatively few environmental factors are investigated, this approach can save time and labor to formulate a conservation management plan for degraded alpine meadows.

[Relocation of Espeletia grandiflora (Asteraceae) plants as a strategy for enrichment of disturbed paramo areas (PNN Chingaza, Colombia)].

PubMed

Rojas-Zamora, Oscar; Insuasty-Torres, Jennyfer; de Cardenas, Camilo los Angeles; Ríos, Orlando Vargas

2013-03-01

Ecological restoration of the Andean paramos faces several ecological barriers mainly at the phase of dispersal and establishment of native species. With the aim to contribute to the enrichment of degraded areas, different strategies have to be developed to overcome those barriers. In this work we studied the response of individuals of Espeletia grandiflora (Asteraceae) to the relocation as a strategy for ecological restoration programs. We also evaluated the effect of size of relocated individuals on their survival and development. The work was carried out in an experimental plot at 3 424m altitude in the sector "Lagunas de Siecha" of Chingaza National Park, Colombia. We relocated 200 plants that belonged to three different size classes: 5, 10 and 15cm of initial height. The following variables were registered: survival, plant height, number of living leaves and stem diameter of each individual. We also evaluated the differences between individuals in survival and development. In terms of survival the most efficient size classes corresponded to 15cm high; the survival was 85% after two years. The relative growth rates for height and stem diameter decreases with the increase in size, but the absolute increase in height did not show significant differences between the three sizes tested. Since the stem diameter was found the strongest survival predictor after two years of relocation activities, we suggest its use as a criterion for selection of relocation individuals. The relocation of individuals of E. grandiflora had a positive side effect, carrying other species that may contribute to the enrichment and restoration of degraded areas. Among these, we found species of the genus Hypericum, as well as Arcytophyllum nitidum and Calamagrostis effusa, which should be evaluated in terms of survival and development for the subsequent implementation of the relocation strategy. In this study we verified the successful relocation of individuals of E. grandiflora as a

Glutathione Degradation.

PubMed

Bachhawat, Anand Kumar; Kaur, Amandeep

2017-11-20

Glutathione degradation has for long been thought to occur only on noncytosolic pools. This is because there has been only one enzyme known to degrade glutathione (γ-glutamyl transpeptidase) and this localizes to either the plasma membrane (mammals, bacteria) or the vacuolar membrane (yeast, plants) and acts on extracellular or vacuolar pools. The last few years have seen the discovery of several new enzymes of glutathione degradation that function in the cytosol, throwing new light on glutathione degradation. Recent Advances: The new enzymes that have been identified in the last few years that can initiate glutathione degradation include the Dug enzyme found in yeast and fungi, the ChaC1 enzyme found among higher eukaryotes, the ChaC2 enzyme found from bacteria to man, and the RipAY enzyme found in some bacteria. These enzymes play roles ranging from housekeeping functions to stress responses and are involved in processes such as embryonic neural development and pathogenesis. In addition to delineating the pathways of glutathione degradation in detail, a critical issue is to find how these new enzymes impact cellular physiology and homeostasis. Glutathione degradation plays a far greater role in cellular physiology than previously envisaged. The differential regulation and differential specificities of various enzymes, each acting on distinct pools, can lead to different consequences to the cell. It is likely that the coming years will see these downstream effects being unraveled in greater detail and will lead to a better understanding and appreciation of glutathione degradation. Antioxid. Redox Signal. 27, 1200-1216.

Effects of Planting and Processing Modes on the Degradation of Dithianon and Pyraclostrobin in Chinese Yam (Dioscorea spp.).

PubMed

Shi, Kaiwei; Wu, Xujin; Ma, Jingwei; Zhang, Junfeng; Zhou, Ling; Wang, Hong; Li, Li

2017-12-06

The yam (Dioscorea spp.) is widely cultivated in China. The degradation of dithianon and pyraclostrobin in yams with different planting and processing treatments was investigated in this article. An analytical method for two pesticides in yam and yam plant was developed, and recoveries were between 77% and 93%, with relative standard deviations from 0.8% to 7.4%, respectively. On the basis of this method, half-lives for plants grown on stakes versus plants grown without stakes were compared. The results indicated that the half-life for pesticide residues for plants grown on stakes versus plants grown without stakes differed as 6.7 versus 3.1 days for dithianon and 5.4 versus 5.2 days for pyraclostrobin. Dithianon was significantly influenced by planting mode because of its low stability under sunlight. The processing factors of various processing treatments (hot air-drying, vacuum freeze-drying, microwave vacuum-drying, infrared-drying, steaming, and boiling) were all <1, indicating that those processes can reduce residues of two pesticides at different levels. Significant amounts of residues were removed during the boiling treatment, whereas the others showed less effect.

Potential of native shrubs Haloxylon salicornicum and Calligonum Polygonoides for restoration of degraded lands in Arid Western Rajasthan, India.

PubMed

Rathore, V S; Singh, J P; Bhardwaj, S; Nathawat, N S; Kumar, Mahesh; Roy, M M

2015-01-01

Shrub-induced soil property spatial heterogeneity is common in arid and semi-arid ecosystems and aids desertified land restoration. However, the effectiveness of this technique may rely on the plant species used and the habitat conditions present. To assess the degree to which planting two native species, Haloxylon salicornicum and Calligonum polygonoides, facilitates degraded land restoration, soil and herbaceous plant community properties were measured 7 years after planting. Soil samples were extracted at two depths (0-5 and 5-20 cm) from three sub-habitats, i.e., under the shrub canopy, from alleys between shrubs and from the open area. Shrub planting increased the quantity of silt + clay content (30-39 %); enhanced water holding capacities (24-30 %); increased the levels of organic carbon (48-69 %), available nitrogen (31-47 %), available phosphorus (32-41 %), and electrical conductivity (21-33 %); and decreased the pH (7-12 %) and bulk density levels (5-6 %) in the surface layer of soils beneath the canopy. Soil property changes were more significant at the surface (0-5 cm) than in the deeper layer (5-20 cm), and were more pronounced under H. salicornicum than under C. polygonoides. Furthermore, the density and biomass levels of herbaceous plants were 1.1 to 1.2 and 1.4 to 1.6 times greater, respectively, in the shrub alleys than in open area. H. salicornicum induced more robust soil amelioration and herbaceous plant facilitative properties than did C. polygonoides. Artificially planting these shrubs may thus be employed to restore degraded areas of arid regions.

Metatranscriptomic Analyses of Plant Cell Wall Polysaccharide Degradation by Microorganisms in the Cow Rumen

PubMed Central

Dai, Xin; Tian, Yan; Li, Jinting; Su, Xiaoyun; Wang, Xuewei; Zhao, Shengguo; Liu, Li; Luo, Yingfeng; Liu, Di; Zheng, Huajun; Wang, Jiaqi; Dong, Zhiyang

2014-01-01

The bovine rumen represents a highly specialized bioreactor where plant cell wall polysaccharides (PCWPs) are efficiently deconstructed via numerous enzymes produced by resident microorganisms. Although a large number of fibrolytic genes from rumen microorganisms have been identified, it remains unclear how they are expressed in a coordinated manner to efficiently degrade PCWPs. In this study, we performed a metatranscriptomic analysis of the rumen microbiomes of adult Holstein cows fed a fiber diet and obtained a total of 1,107,083 high-quality non-rRNA reads with an average length of 483 nucleotides. Transcripts encoding glycoside hydrolases (GHs) and carbohydrate binding modules (CBMs) accounted for ∼1% and ∼0.1% of the total non-rRNAs, respectively. The majority (∼98%) of the putative cellulases belonged to four GH families (i.e., GH5, GH9, GH45, and GH48) and were primarily synthesized by Ruminococcus and Fibrobacter. Notably, transcripts for GH48 cellobiohydrolases were relatively abundant compared to the abundance of transcripts for other cellulases. Two-thirds of the putative hemicellulases were of the GH10, GH11, and GH26 types and were produced by members of the genera Ruminococcus, Prevotella, and Fibrobacter. Most (∼82%) predicted oligosaccharide-degrading enzymes were GH1, GH2, GH3, and GH43 proteins and were from a diverse group of microorganisms. Transcripts for CBM10 and dockerin, key components of the cellulosome, were also relatively abundant. Our results provide metatranscriptomic evidence in support of the notion that members of the genera Ruminococcus, Fibrobacter, and Prevotella are predominant PCWP degraders and point to the significant contribution of GH48 cellobiohydrolases and cellulosome-like structures to efficient PCWP degradation in the cow rumen. PMID:25501482

Role of soil sorption and microbial degradation on dissipation of mesotrione in plant-available soil water.

PubMed

Shaner, Dale; Brunk, Galen; Nissen, Scott; Westra, Phil; Chen, Wenlin

2012-01-01

Mesotrione is a carotenoid biosynthesis-inhibiting herbicide labeled for pre-emergence and postemergence weed control in corn production. Understanding the factors that influence the dissipation of mesotrione in soil and in the plant-available water (PAW) is important for the environmental fate assessment and optimal weed management practices. The present research investigated the role of soil properties and microbial activities on the interrelated sorption and degradation processes of mesotrione in four soils by direct measurements of PAW. We found that mesotrione bound to the soils time dependently, with approximately 14 d to reach equilibrium. The 24-h batch-slurry equilibrium experiments provided the sorption partition coefficient ranging from 0.26 to 3.53 L kg(-1), depending on soil organic carbon and pH. The dissipation of mesotrione in the soil-bound phase was primarily attributed to desorption to the PAW. Degradation in the PAW was rapid and primarily dependent on microbial actions, with half-degradation time (DT(50)) <3 d in all four soils tested. The rapid degradation in the PAW became rate limited by sorption as more available molecules were depleted in the soil pore water, resulting in a more slowed overall process for the total soil-water system (DT(50) <26 d). The dissipation of mesotrione in the PAW was due to microbial metabolism and time-dependent sorption to the soils. A coupled kinetics model calibrated with the data from the laboratory centrifugation technique provided an effective approach to investigate the interrelated processes of sorption and degradation in realistic soil moisture conditions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Atmospheric transformation of plant volatiles disrupts host plant finding

NASA Astrophysics Data System (ADS)

Li, Tao; Blande, James D.; Holopainen, Jarmo K.

2016-09-01

Plant-emitted volatile organic compounds (VOCs) play important roles in plant-insect interactions. Atmospheric pollutants such as ozone (O3) can react with VOCs and affect the dynamics and fidelity of these interactions. However, the effects of atmospheric degradation of plant VOCs on plant-insect interactions remains understudied. We used a system comprising Brassica oleracea subsp. capitata (cabbage) and the specialist herbivore Plutella xylostella to test whether O3-triggered VOC degradation disturbs larval host orientation, and to investigate the underlying mechanisms. Larvae oriented towards both constitutive and larva-induced cabbage VOC blends, the latter being the more attractive. Such behaviour was, however, dramatically reduced in O3-polluted environments. Mechanistically, O3 rapidly degraded VOCs with the magnitude of degradation increasing with O3 levels. Furthermore, we used Teflon filters to collect VOCs and their reaction products, which were used as odour sources in behavioural tests. Larvae avoided filters exposed to O3-transformed VOCs and spent less time searching on them compared to filters exposed to original VOCs, which suggests that some degradation products may have repellent properties. Our study clearly demonstrates that oxidizing pollutants in the atmosphere can interfere with insect host location, and highlights the need to address their broader impacts when evaluating the ecological significance of VOC-mediated interactions.

ARCHITECTURAL FLOOR PLAN OF OPERATING AREA HOT PILOT PLANT (CPP640). ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ARCHITECTURAL FLOOR PLAN OF OPERATING AREA HOT PILOT PLANT (CPP-640). INL DRAWING NUMBER 200-0640-00-279-111678. ALTERNATE ID NUMBER 8952-CPP-640-A-1. - Idaho National Engineering Laboratory, Idaho Chemical Processing Plant, Fuel Reprocessing Complex, Scoville, Butte County, ID

Efficient Degradation of Lignocellulosic Plant Biomass, without Pretreatment, by the Thermophilic Anaerobe “Anaerocellum thermophilum” DSM 6725▿

PubMed Central

Yang, Sung-Jae; Kataeva, Irina; Hamilton-Brehm, Scott D.; Engle, Nancy L.; Tschaplinski, Timothy J.; Doeppke, Crissa; Davis, Mark; Westpheling, Janet; Adams, Michael W. W.

2009-01-01

Very few cultivated microorganisms can degrade lignocellulosic biomass without chemical pretreatment. We show here that “Anaerocellum thermophilum” DSM 6725, an anaerobic bacterium that grows optimally at 75°C, efficiently utilizes various types of untreated plant biomass, as well as crystalline cellulose and xylan. These include hardwoods such as poplar, low-lignin grasses such as napier and Bermuda grasses, and high-lignin grasses such as switchgrass. The organism did not utilize only the soluble fraction of the untreated biomass, since insoluble plant biomass (as well as cellulose and xylan) obtained after washing at 75°C for 18 h also served as a growth substrate. The predominant end products from all growth substrates were hydrogen, acetate, and lactate. Glucose and cellobiose (on crystalline cellulose) and xylose and xylobiose (on xylan) also accumulated in the growth media during growth on the defined substrates but not during growth on the plant biomass. A. thermophilum DSM 6725 grew well on first- and second-spent biomass derived from poplar and switchgrass, where spent biomass is defined as the insoluble growth substrate recovered after the organism has reached late stationary phase. No evidence was found for the direct attachment of A. thermophilum DSM 6725 to the plant biomass. This organism differs from the closely related strain A. thermophilum Z-1320 in its ability to grow on xylose and pectin. Caldicellulosiruptor saccharolyticus DSM 8903 (optimum growth temperature, 70°C), a close relative of A. thermophilum DSM 6725, grew well on switchgrass but not on poplar, indicating a significant difference in the biomass-degrading abilities of these two otherwise very similar organisms. PMID:19465524

Biotemplated synthesis of high specific surface area copper-doped hollow spherical titania and its photocatalytic research for degradating chlorotetracycline

NASA Astrophysics Data System (ADS)

Bu, Dan; Zhuang, Huisheng

2013-01-01

Copper-doped titania (Cu/TiO2) hollow microspheres were fabricated using the rape pollen as biotemplates via an improved sol-gel method and a followed calcinations process. In the fabricated process, a titanium(IV)-isopropoxide-based sol directly coated onto the surface of rape pollen. Subsequently, after calcinations, rape pollen was removed by high temperature and the hollow microsphere structure was retained. The average diameter of as-obtained hollow microspheres is 15-20 μm and the thickness of shell is approximately 0.6 μm. Knowing from XRD results, the main crystal phase of microspheres is anatase, coupled with rutile. The specific surface area varied between 141.80 m2/g and 172.51 m2/g. This hollow sphere photocatalysts with high specific surface area exhibited stronger absorption ability and higher photoactivity, stimulated by visible light. The degradation process of chlortetracycline (CTC) solution had been studied. The degradated results indicate that CTC could be effective degradated by fabricated hollow spherical materials. And the intermediate products formed in the photocatalytic process had been identified.

Chlorophyll b degradation by chlorophyll b reductase under high-light conditions.

PubMed

Sato, Rei; Ito, Hisashi; Tanaka, Ayumi

2015-12-01

The light-harvesting chlorophyll a/b binding protein complex of photosystem II (LHCII) is the main antenna complex of photosystem II (PSII). Plants change their LHCII content depending on the light environment. Under high-light conditions, the content of LHCII should decrease because over-excitation damages the photosystem. Chlorophyll b is indispensable for accumulating LHCII, and chlorophyll b degradation induces LHCII degradation. Chlorophyll b degradation is initiated by chlorophyll b reductase (CBR). In land plants, NON-YELLOW COLORING 1 (NYC1) and NYC1-Like (NOL) are isozymes of CBR. We analyzed these mutants to determine their functions under high-light conditions. During high-light treatment, the chlorophyll a/b ratio was stable in the wild-type (WT) and nol plants, and the LHCII content decreased in WT plants. The chlorophyll a/b ratio decreased in the nyc1 and nyc1/nol plants, and a substantial degree of LHCII was retained in nyc1/nol plants after the high-light treatment. These results demonstrate that NYC1 degrades the chlorophyll b on LHCII under high-light conditions, thus decreasing the LHCII content. After the high-light treatment, the maximum quantum efficiency of the PSII photochemistry was lower in nyc1 and nyc1/nol plants than in WT and nol plants. A larger light-harvesting system would damage PSII in nyc1 and nyc1/nol plants. The fluorescence spectroscopy of the leaves indicated that photosystem I was also damaged by the excess LHCII in nyc1/nol plants. These observations suggest that chlorophyll b degradation by NYC1 is the initial reaction for the optimization of the light-harvesting capacity under high-light conditions.

Molecular Mechanisms Associated with Xylan Degradation by Xanthomonas Plant Pathogens*

PubMed Central

Santos, Camila Ramos; Hoffmam, Zaira Bruna; de Matos Martins, Vanesa Peixoto; Zanphorlin, Leticia Maria; de Paula Assis, Leandro Henrique; Honorato, Rodrigo Vargas; Lopes de Oliveira, Paulo Sérgio; Ruller, Roberto; Murakami, Mario Tyago

2014-01-01

Xanthomonas pathogens attack a variety of economically relevant plants, and their xylan CUT system (carbohydrate utilization with TonB-dependent outer membrane transporter system) contains two major xylanase-related genes, xynA and xynB, which influence biofilm formation and virulence by molecular mechanisms that are still elusive. Herein, we demonstrated that XynA is a rare reducing end xylose-releasing exo-oligoxylanase and not an endo-β-1,4-xylanase as predicted. Structural analysis revealed that an insertion in the β7-α7 loop induces dimerization and promotes a physical barrier at the +2 subsite conferring this unique mode of action within the GH10 family. A single mutation that impaired dimerization became XynA active against xylan, and high endolytic activity was achieved when this loop was tailored to match a canonical sequence of endo-β-1,4-xylanases, supporting our mechanistic model. On the other hand, the divergent XynB proved to be a classical endo-β-1,4-xylanase, despite the low sequence similarity to characterized GH10 xylanases. Interestingly, this enzyme contains a calcium ion bound nearby to the glycone-binding region, which is required for catalytic activity and structural stability. These results shed light on the molecular basis for xylan degradation by Xanthomonas and suggest how these enzymes synergistically assist infection and pathogenesis. Our findings indicate that XynB contributes to breach the plant cell wall barrier, providing nutrients and facilitating the translocation of effector molecules, whereas the exo-oligoxylanase XynA possibly participates in the suppression of oligosaccharide-induced immune responses. PMID:25266726

Novel ideas for maximising dew collection to aid plant establishment to combat desertification and restore degraded dry and arid lands

NASA Astrophysics Data System (ADS)

Kotzen, Benz

2014-05-01

This paper focuses on the potential of dew to provide water to plants and potentially to people as well in remote and difficult to reach areas where rainfall and underground water cannot be harvested. The combat of desertification and the restoration of degraded and desertified dry and arid lands has never been more urgent. A key practical component of this strategy is the restoration of habitat with planting. But for habitat and planting to survive there needs to be an adequate supply of water. In most cases providing water to the plant's roots is vital. In some areas where habitats have been destroyed, sufficient water is immediately available, for example through seasonal rainfall, or it can be harvested to concentrate adequate supplies of water to the roots. However, in arid and hyper arid areas, as well as in some dryland areas, a consistent and adequate supply of water cannot be provided by any conventional proven method. Thus, as the need to combat desertification and to restore desertified dry and arid land increases, so the need to find novel methods of establishing and maintaining planting and thus habitat increases. In more traditional land management scenarios this can be achieved through manipulating landform on a micro and macro scale, for example, by creating catchments, thereby collecting precipitation and directing it to the plants. Where this cannot be done, other means of water supply are usually required. Bainbridge (2007) and others have shown that supplying water to plants is possible through a number of traditional methods, for example, using clay pots. But most of these techniques require an introduced source of water, for example, obtained through water harvesting methods or by delivering water to site in tanks and by water bowser. This can work but requires continuous manpower. It is expensive and can be physically prohibitive in areas where access is difficult and/or remote. The concept of using dew to supply water in drylands is not new

Effect of power plant emission reductions on a nearby wilderness area: a case study in northwestern Colorado

USGS Publications Warehouse

Mast, M. Alisa; Ely, Daniel

2013-01-01

This study evaluates the effect of emission reductions at two coal-fired power plants in northwestern Colorado on a nearby wilderness area. Control equipment was installed at both plants during 1999–2004 to reduce SO2 and NOx emissions. One challenge was separating the effects of local from regional emissions, which also declined during the study period. The long-term datasets examined confirm that emission reductions had a beneficial effect on air and water quality in the wilderness. Despite a 75 % reduction in SO2 emissions, sulfate aerosols measured in the wilderness decreased by only 20 %. Because the site is relatively close to the power plants (2 to sulfate, particularly under conditions of low relative humidity, might account for this less than one-to-one response. On the clearest days, emissions controls appeared to improve visibility by about 1 deciview, which is a small but perceptible improvement. On the haziest days, however, there was little improvement perhaps reflecting the dominance of regional haze and other components of visibility degradation particularly organic carbon and dust. Sulfate and acidity in atmospheric deposition decreased by 50 % near the southern end of the wilderness of which 60 % was attributed to power plant controls and the remainder to reductions in regional sources. Lake water sulfate responded rapidly to trends in deposition declining at 28 lakes monitored in and near the wilderness. Although no change in the acid–base status was observed, few of the lakes appear to be at risk from chronic or episodic acidification.

Plant invasions in protected areas of tropical pacific islands, with special reference to Hawaii

USGS Publications Warehouse

Hughes, R. Flint; Meyer, Jean-Yves; Loope, Lloyd L.

2013-01-01

Isolated tropical islands are notoriously vulnerable to plant invasions. Serious management for protection of native biodiversity in Hawaii began in the 1970s, arguably at Hawaii Volcanoes National Park. Concerted alien plant management began there in the 1980s and has in a sense become a model for protected areas throughout Hawaii and Pacific Island countries and territories. We review the relative successes of their strategies and touch upon how their experience has been applied elsewhere. Protected areas in Hawaii are fortunate in having relatively good resources for addressing plant invasions, but many invasions remain intractable, and invasions from outside the boundaries continue from a highly globalised society with a penchant for horticultural novelty. There are likely few efforts in most Pacific Islands to combat alien plant invasions in protected areas, but such areas may often have fewer plant invasions as a result of their relative remoteness and/or socio-economic development status. The greatest current needs for protected areas in this region may be for establishment of yet more protected areas, for better resources to combat invasions in Pacific Island countries and territories, for more effective control methods including biological control programme to contain intractable species, and for meaningful efforts to address prevention and early detection of potential new invaders.

Production by Tobacco Transplastomic Plants of Recombinant Fungal and Bacterial Cell-Wall Degrading Enzymes to Be Used for Cellulosic Biomass Saccharification.

PubMed

Longoni, Paolo; Leelavathi, Sadhu; Doria, Enrico; Reddy, Vanga Siva; Cella, Rino

2015-01-01

Biofuels from renewable plant biomass are gaining momentum due to climate change related to atmospheric CO2 increase. However, the production cost of enzymes required for cellulosic biomass saccharification is a major limiting step in this process. Low-cost production of large amounts of recombinant enzymes by transgenic plants was proposed as an alternative to the conventional microbial based fermentation. A number of studies have shown that chloroplast-based gene expression offers several advantages over nuclear transformation due to efficient transcription and translation systems and high copy number of the transgene. In this study, we expressed in tobacco chloroplasts microbial genes encoding five cellulases and a polygalacturonase. Leaf extracts containing the recombinant enzymes showed the ability to degrade various cell-wall components under different conditions, singly and in combinations. In addition, our group also tested a previously described thermostable xylanase in combination with a cellulase and a polygalacturonase to study the cumulative effect on the depolymerization of a complex plant substrate. Our results demonstrate the feasibility of using transplastomic tobacco leaf extracts to convert cell-wall polysaccharides into reducing sugars, fulfilling a major prerequisite of large scale availability of a variety of cell-wall degrading enzymes for biofuel industry.

Landscape functionality of plant communities in the Impala Platinum mining area, Rustenburg.

PubMed

van der Walt, L; Cilliers, S S; Kellner, K; Tongway, D; van Rensburg, L

2012-12-30

The tremendous growth of the platinum mining industry in South Africa has affected the natural environment adversely. The waste produced by platinum mineral processing is alkaline, biologically sterile and has a low water-holding capacity. These properties in the environment may constitute dysfunctional areas that will create 'leaky' and dysfunctional landscapes, limiting biological development. Landscape Function Analysis (LFA) is a monitoring procedure that assesses the degradation of landscapes, as brought about by human, animal and natural activities, through rapidly assessing certain soil surface indicators which indicate the biophysical functionality of the system. The "Trigger-Transfer-Reserve-Pulse" (TTRP) conceptual framework forms the foundation for assessing landscape function when using LFA. The two main aspects of this framework are the loss of resources from the system and the utilisation of resources by the system. After a survey of landscape heterogeneity to reflect the spatial organisation of the landscape, soil surface indicators are assessed within different patch types (identifiable units that retains resources that pass through the system) and interpatches (units between patches where vital resources are not retained, but lost) to assess the capacity of patches with various physical properties in regulating the effectiveness of resource control in the landscape. Indices describing landscape organisation are computed by a spreadsheet analysis, as well as soil surface quality indices. When assembled in different combinations, three indices emerge that reflect soil productive potential, namely: the (1) surface stability, (2) infiltration capacity, and (3) the nutrient cycling potential of the landscape. In this study we compared the landscape functionality of natural thornveld areas, rehabilitated opencast mines and rehabilitated slopes of tailings dams in the area leased for mining in the Rustenburg area. Our results show that the rehabilitated

Isolation and characterization of mesophilic, oxalate-degrading Streptomyces from plant rhizosphere and forest soils

NASA Astrophysics Data System (ADS)

Sahin, Nurettin

2004-10-01

The present work was aimed at the isolation of additional new pure cultures of oxalate-degrading Streptomyces and its preliminary characterization for further work in the field of oxalate metabolism and taxonomic studies. Mesophilic, oxalate-degrading Streptomyces were enriched and isolated from plant rhizosphere and forest soil samples. Strains were examined for cultural, morphological (spore chain morphology, spore mass colour, diffusible and melanin pigment production), physiological (antibiosis, growth in the presence of inhibitory compounds, assimilation of organic acids and enzyme substrates) and chemotaxonomic characters (cellular lipid components and diagnostic cell-wall diamino acid). The taxonomic data obtained were analysed by using the simple matching (SSM) and Jaccard (SJ) coefficients, clustering was achieved using the UPGMA algorithm. All strains were able to utilize sodium-, potassium-, calcium- and ammonium-oxalate salts. Based on the results of numerical taxonomy, isolates were grouped into five cluster groups with a ≥70% SSM similarity level. Streptomyces rochei was the most common of the cluster groups, with a Willcox probability of P>0.8. Streptomyces antibioticus, S. anulatus, S. fulvissimus, S. halstedii and S. violaceusniger are newly reported as oxalate-utilizing Streptomyces.

Atmospheric transformation of plant volatiles disrupts host plant finding

PubMed Central

Li, Tao; Blande, James D.; Holopainen, Jarmo K.

2016-01-01

Plant-emitted volatile organic compounds (VOCs) play important roles in plant-insect interactions. Atmospheric pollutants such as ozone (O3) can react with VOCs and affect the dynamics and fidelity of these interactions. However, the effects of atmospheric degradation of plant VOCs on plant-insect interactions remains understudied. We used a system comprising Brassica oleracea subsp. capitata (cabbage) and the specialist herbivore Plutella xylostella to test whether O3-triggered VOC degradation disturbs larval host orientation, and to investigate the underlying mechanisms. Larvae oriented towards both constitutive and larva-induced cabbage VOC blends, the latter being the more attractive. Such behaviour was, however, dramatically reduced in O3-polluted environments. Mechanistically, O3 rapidly degraded VOCs with the magnitude of degradation increasing with O3 levels. Furthermore, we used Teflon filters to collect VOCs and their reaction products, which were used as odour sources in behavioural tests. Larvae avoided filters exposed to O3-transformed VOCs and spent less time searching on them compared to filters exposed to original VOCs, which suggests that some degradation products may have repellent properties. Our study clearly demonstrates that oxidizing pollutants in the atmosphere can interfere with insect host location, and highlights the need to address their broader impacts when evaluating the ecological significance of VOC-mediated interactions. PMID:27651113

Prioritizing conservation areas for coastal plant diversity under increasing urbanization.

PubMed

Doxa, Aggeliki; Albert, Cécile Hélène; Leriche, Agathe; Saatkamp, Arne

2017-10-01

Coastal urban expansion will continue to drive further biodiversity losses, if conservation targets for coastal ecosystems are not defined and met. Prioritizing areas for future protected area networks is thus an urgent task in such urbanization-threatened ecosystems. Our aim is to quantify past and future losses of coastal vegetation priority areas due to urbanization and assess the effectiveness of the existing protected area network for conservation. We conduct a prioritization analysis, based on 82 coastal plants, including common and IUCN red list species, in a highly-urbanized but biotically diverse region, in South-Eastern France. We evaluate the role of protected areas, by taking into account both strict and multi-use areas. We assess the impact of past and future urbanization on high priority areas, by combining prioritization analyses and urbanization models. We show that half of the highly diverse areas have already been lost due to urbanization. Remaining top priority areas are also among the most exposed to future urban expansion. The effectiveness of the existing protected area (PA) network is only partial. While strict PAs coincide well with top priority areas, they only represent less than one third of priority areas. The effectiveness of multi-use PAs, such as the Natura 2000 network, also remains limited. Our approach highlights the impact of urbanization on plant conservation targets. By modelling urbanization, we manage to identify those areas where protection could be more efficient to limit further losses. We suggest to use our approach in the future to expand the PA network in order to achieve the 2020 Aichi biodiversity targets. Copyright © 2017 Elsevier Ltd. All rights reserved.

Escaping Underground Nets: Extracellular DNases Degrade Plant Extracellular Traps and Contribute to Virulence of the Plant Pathogenic Bacterium Ralstonia solanacearum

PubMed Central

Tran, Tuan Minh; MacIntyre, April; Hawes, Martha; Allen, Caitilyn

2016-01-01

Plant root border cells have been recently recognized as an important physical defense against soil-borne pathogens. Root border cells produce an extracellular matrix of protein, polysaccharide and DNA that functions like animal neutrophil extracellular traps to immobilize pathogens. Exposing pea root border cells to the root-infecting bacterial wilt pathogen Ralstonia solanacearum triggered release of DNA-containing extracellular traps in a flagellin-dependent manner. These traps rapidly immobilized the pathogen and killed some cells, but most of the entangled bacteria eventually escaped. The R. solanacearum genome encodes two putative extracellular DNases (exDNases) that are expressed during pathogenesis, suggesting that these exDNases contribute to bacterial virulence by enabling the bacterium to degrade and escape root border cell traps. We tested this hypothesis with R. solanacearum deletion mutants lacking one or both of these nucleases, named NucA and NucB. Functional studies with purified proteins revealed that NucA and NucB are non-specific endonucleases and that NucA is membrane-associated and cation-dependent. Single ΔnucA and ΔnucB mutants and the ΔnucA/B double mutant all had reduced virulence on wilt-susceptible tomato plants in a naturalistic soil-soak inoculation assay. The ΔnucA/B mutant was out-competed by the wild-type strain in planta and was less able to stunt root growth or colonize plant stems. Further, the double nuclease mutant could not escape from root border cells in vitro and was defective in attachment to pea roots. Taken together, these results demonstrate that extracellular DNases are novel virulence factors that help R. solanacearum successfully overcome plant defenses to infect plant roots and cause bacterial wilt disease. PMID:27336156

Determination of coefficient defining leaf area development in different genotypes, plant types and planting densities in peanut (Arachis hypogeae L.).

PubMed

Halilou, Oumarou; Hissene, Halime Mahamat; Clavijo Michelangeli, José A; Hamidou, Falalou; Sinclair, Thomas R; Soltani, Afshin; Mahamane, Saadou; Vadez, Vincent

2016-12-01

Rapid leaf area development may be attractive under a number of cropping conditions to enhance the vigor of crop establishment and allow rapid canopy closure for maximizing light interception and shading of weed competitors. This study was undertaken to determine (1) if parameters describing leaf area development varied among ten peanut ( Arachis hypogeae L.) genotypes grown in field and pot experiments, (2) if these parameters were affected by the planting density, and (3) if these parameters varied between Spanish and Virginia genotypes. Leaf area development was described by two steps: prediction of main stem number of nodes based on phyllochron development and plant leaf area dependent based on main stem node number. There was no genetic variation in the phyllochron measured in the field. However, the phyllochron was much longer for plants grown in pots as compared to the field-grown plants. These results indicated a negative aspect of growing peanut plants in the pots used in this experiment. In contrast to phyllochron, there was no difference in the relationship between plant leaf area and main stem node number between the pot and field experiments. However, there was genetic variation in both the pot and field experiments in the exponential coefficient (PLAPOW) of the power function used to describe leaf area development from node number. This genetic variation was confirmed in another experiment with a larger number of genotypes, although possible G × E interaction for the PLAPOW was found. Sowing density did not affect the power function relating leaf area to main stem node number. There was also no difference in the power function coefficient between Spanish and Virginia genotypes. SSM (Simple Simulation model) reliably predicted leaf canopy development in groundnut. Indeed the leaf area showed a close agreement between predicted and observed values up to 60000 cm 2  m -2 . The slightly higher prediction in India and slightly lower prediction in

Assessing shortfalls and complementary conservation areas for national plant biodiversity in South Korea.

PubMed

Choe, Hyeyeong; Thorne, James H; Huber, Patrick R; Lee, Dongkun; Quinn, James F

2018-01-01

Protected areas (PAs) are often considered the most important biodiversity conservation areas in national plans, but PAs often do not represent national-scale biodiversity. We evaluate the current conservation status of plant biodiversity within current existing PAs, and identify potential additional PAs for South Korea. We modeled species ranges for 2,297 plant species using Multivariate Adaptive Regression Splines and compared the level of mean range representation in South Korea's existing PAs, which comprise 5.7% of the country's mainland area, with an equal-area alternative PA strategy selected with the reserve algorithm Marxan. We also used Marxan to model two additional conservation scenarios that add lands to approach the Aichi Biodiversity Target objectives (17% of the country). Existing PAs in South Korea contain an average of 6.3% of each plant species' range, compared to 5.9% in the modeled equal-area alternative. However, existing PAs primarily represent a high percentage of the ranges for high-elevation and small range size species. The additional PAs scenario that adds lands to the existing PAs covers 14,587.55 km2, and would improve overall plant range representation to a mean of 16.8% of every species' range. The other additional PAs scenario, which selects new PAs from all lands and covers 13,197.35 km2, would improve overall plant range representation to a mean of 13.5%. Even though the additional PAs that includes existing PAs represents higher percentages of species' ranges, it is missing many biodiversity hotspots in non-mountainous areas and the additional PAs without locking in the existing PAs represent almost all species' ranges evenly, including low-elevation ones with larger ranges. Some priority conservation areas we identified are expansions of, or near, existing PAs, especially in northeastern and southern South Korea. However, lowland coastal areas and areas surrounding the capital city, Seoul, are also critical for biodiversity

Assessing shortfalls and complementary conservation areas for national plant biodiversity in South Korea

PubMed Central

Thorne, James H.; Huber, Patrick R.; Lee, Dongkun; Quinn, James F.

2018-01-01

Protected areas (PAs) are often considered the most important biodiversity conservation areas in national plans, but PAs often do not represent national-scale biodiversity. We evaluate the current conservation status of plant biodiversity within current existing PAs, and identify potential additional PAs for South Korea. We modeled species ranges for 2,297 plant species using Multivariate Adaptive Regression Splines and compared the level of mean range representation in South Korea’s existing PAs, which comprise 5.7% of the country’s mainland area, with an equal-area alternative PA strategy selected with the reserve algorithm Marxan. We also used Marxan to model two additional conservation scenarios that add lands to approach the Aichi Biodiversity Target objectives (17% of the country). Existing PAs in South Korea contain an average of 6.3% of each plant species’ range, compared to 5.9% in the modeled equal-area alternative. However, existing PAs primarily represent a high percentage of the ranges for high-elevation and small range size species. The additional PAs scenario that adds lands to the existing PAs covers 14,587.55 km2, and would improve overall plant range representation to a mean of 16.8% of every species’ range. The other additional PAs scenario, which selects new PAs from all lands and covers 13,197.35 km2, would improve overall plant range representation to a mean of 13.5%. Even though the additional PAs that includes existing PAs represents higher percentages of species’ ranges, it is missing many biodiversity hotspots in non-mountainous areas and the additional PAs without locking in the existing PAs represent almost all species’ ranges evenly, including low-elevation ones with larger ranges. Some priority conservation areas we identified are expansions of, or near, existing PAs, especially in northeastern and southern South Korea. However, lowland coastal areas and areas surrounding the capital city, Seoul, are also critical for

Checklist of the vascular plants of Steamboat Mountain Research Natural Area.

Treesearch

S. Reid Schuller; Robert E. Frenkel

1981-01-01

Lists 237 vascular plant taxa found in the 570-hectare Steamboat Mountain Research Natural Area. Notes on habitats, community types, and abundance are included for most taxa. This research note provides scientists, educators, and land managers with baseline information on the presence, location, and abundance of vascular plants within the Steamboat Mountain Research...

[Species composition, distribution and phenological characters of pollen-allergenic plants in Beijing urban area].

PubMed

Ouyang, Zhi-Yun; Xin, Jia-Nan; Zheng, Hua; Meng, Xue-Song; Wang, Xiao-Ke

2007-09-01

In order to know the species composition, distribution pattern, and phenological characteristics of pollen-allergenic plants in Beijing urban area, an investigation was made, combined with literature survey and experts interviews. The results showed that within the fifth ring of Beijing, there were 99 pollen-allergenic plant species belonging to 32 genera and 19 families, among which, 52 species were native plants, accounting for 52.5% of the total, 26 species were introduced from other regions of China, occupying 26.3% of the total, and 21 species were introduced from foreign countries, being 21.2% of the total. The 32 genera of pollen-allergenic plants in Beijing urban area were mainly North Temperate elements, occupying 40.6% , followed by Cosmopolitan and Pantropic elements. In all functional sections of Beijing urban area, the pollen-allergenic plants were most diversified in urban parks, and had the highest proportion in street tree species. The coverage of herbs with strong pollen allergy was in the order of waste lands > gym centers and institution yards > greenbelts > parks > residential areas > squares. The blooming period of pollen-allergenic arbors in Beijing urban area was concentrated in March and April, while that of pollen-allergenic herbs was from July to September.

Expanding the FIA inventory to understand plant diversity in Palau’s conservation areas

Treesearch

Matthew O’Driscoll; Ashley Lehman; Mikhail Yatskov

2015-01-01

Palau is well known as an area of high plant diversity; indeed, it is considered the most species rich island group within Micronesia (Kitalong et al., 2008). The Palauan archipelago covers only about 535 km² of land area and yet contains an estimated 730 native plants, including 151 endemic species (Kitalong et al., 2008). Broader scientific interest in Palauan forest...

Uptake of explosives from contaminated soil by existing vegetation at the Iowa Army Ammunition Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, J.F.; Zellmer, S.D.; Tomczyk, N.A.

This study examines the uptake of explosives by existing vegetation growing in soils contaminated with 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitro-3,5-triazine (RDX) in three areas at the Iowa Army Ammunition Plant (IAAP). To determine explosives uptake under natural environmental conditions, existing plant materials and soil from the root zone were sampled at different locations in each area, and plant materials were separated by species. Standard methods were used to determine the concentrations of explosives, their derivatives, and metabolites in the soil samples. Plant materials were also analyzed. The compound TNT was not detected in the aboveground portion of plants, and vegetation growingmore » on TNT-contaminated soils is not considered a health hazard. However, soil and plant roots may contain TNT degradation products that may be toxic; hence, their consumption is not advised. The compound RDX was found in the tops and roots of plants growing on RDX-contaminated soils at all surveyed sites. Although RDX is not a listed carcinogen, several of its potentially present degradation products are carcinogens. Therefore, the consumption of any plant tissues growing on RDX-contaminated sites should be considered a potential health hazard.« less

Bacteria-mediated bisphenol A degradation.

PubMed

Zhang, Weiwei; Yin, Kun; Chen, Lingxin

2013-07-01

Bisphenol A (BPA) is an important monomer in the manufacture of polycarbonate plastics, food cans, and other daily used chemicals. Daily and worldwide usage of BPA and BPA-contained products led to its ubiquitous distribution in water, sediment/soil, and atmosphere. Moreover, BPA has been identified as an environmental endocrine disruptor for its estrogenic and genotoxic activity. Thus, BPA contamination in the environment is an increasingly worldwide concern, and methods to efficiently remove BPA from the environment are urgently recommended. Although many factors affect the fate of BPA in the environment, BPA degradation is mainly depended on the metabolism of bacteria. Many BPA-degrading bacteria have been identified from water, sediment/soil, and wastewater treatment plants. Metabolic pathways of BPA degradation in specific bacterial strains were proposed, based on the metabolic intermediates detected during the degradation process. In this review, the BPA-degrading bacteria were summarized, and the (proposed) BPA degradation pathway mediated by bacteria were referred.

Defluorination of Sodium Fluoroacetate by Bacteria from Soil and Plants in Brazil

PubMed Central

Camboim, Expedito K. A.; Tadra-Sfeir, Michelle Z.; de Souza, Emanuel M.; Pedrosa, Fabio de O.; Andrade, Paulo P.; McSweeney, Chris S.; Riet-Correa, Franklin; Melo, Marcia A.

2012-01-01

The aim of this work was to isolate and identify bacteria able to degrade sodium fluoroacetate from soil and plant samples collected in areas where the fluoroacetate-containing plants Mascagnia rigida and Palicourea aenofusca are found. The samples were cultivated in mineral medium added with 20 mmol L−1 sodium fluoroacetate. Seven isolates were identified by 16S rRNA gene sequencing as Paenibacillus sp. (ECPB01), Burkholderia sp. (ECPB02), Cupriavidus sp. (ECPB03), Staphylococcus sp. (ECPB04), Ancylobacter sp. (ECPB05), Ralstonia sp. (ECPB06), and Stenotrophomonas sp. (ECPB07). All seven isolates degraded sodium-fluoroacetate-containing in the medium, reaching defluorination rate of fluoride ion of 20 mmol L−1. Six of them are reported for the first time as able to degrade sodium fluoroacetate (SF). In the future, some of these microorganisms can be used to establish in the rumen an engineered bacterial population able to degrade sodium fluoroacetate and protect ruminants from the poisoning by this compound. PMID:22619595

Areas of high conservation value at risk by plant invaders in Georgia under climate change.

PubMed

Slodowicz, Daniel; Descombes, Patrice; Kikodze, David; Broennimann, Olivier; Müller-Schärer, Heinz

2018-05-01

Invasive alien plants (IAP) are a threat to biodiversity worldwide. Understanding and anticipating invasions allow for more efficient management. In this regard, predicting potential invasion risks by IAPs is essential to support conservation planning into areas of high conservation value (AHCV) such as sites exhibiting exceptional botanical richness, assemblage of rare, and threatened and/or endemic plant species. Here, we identified AHCV in Georgia, a country showing high plant richness, and assessed the susceptibility of these areas to colonization by IAPs under present and future climatic conditions. We used actual protected areas and areas of high plant endemism (identified using occurrences of 114 Georgian endemic plant species) as proxies for AHCV. Then, we assessed present and future potential distribution of 27 IAPs using species distribution models under four climate change scenarios and stacked single-species potential distribution into a consensus map representing IAPs richness. We evaluated present and future invasion risks in AHCV using IAPs richness as a metric of susceptibility. We show that the actual protected areas cover only 9.4% of the areas of high plant endemism in Georgia. IAPs are presently located at lower elevations around the large urban centers and in western Georgia. We predict a shift of IAPs toward eastern Georgia and higher altitudes and an increased susceptibility of AHCV to IAPs under future climate change. Our study provides a good baseline for decision makers and stakeholders on where and how resources should be invested in the most efficient way to protect Georgia's high plant richness from IAPs.

Land degradation and restoration: The North African experiences

NASA Astrophysics Data System (ADS)

Hirche, azziz; Salamani, mostefa; Boughani, abdelmadjid; Belala, fahima; Essafi, bouajila; Gashut, el-hadi; Hourizi, ratiba; Grandi, mohamed; Ain hamouda, tahar

2017-04-01

The North African steppe, a key area whose economic activity is based on agro-pastoralism, covers 75 million hectares. This steppe underwent significant degradation in the eighties. The combination of severe droughts, the most important of the century, with a peak between 1982-1987 and 2000-2005 and an exponential increase in livestock had a catastrophic impact on pastoral resources. The "alfa" (Stipa tenacissima), an emblematic species of these arid lands, what was called "sea to alfa" is now disappearing. Vegetation cover, which was more than 30% before 1980, is now less than 15%. Concerning the phytomasse, the aboveground dry matter production which exceeds 1ton ha-1 in 1980, is now less than 480 kg.ha-1. At the same time, the agricultural areas in the steppe area, previously marginal, are steadily increasing and reaching several million hectares. This cereal production takes place to the detriment of natural ranges with very low yields (less than 5 quintals per hectare). In response to this deterioration, the North African governments, from the seventies defined different strategies to manage and restore the ecosystems. These ones, based on a socio-economic approach were in summary: (1) To increase pastoral and agricultural production; (2) to reduce livestock; (3) to combine the first two. Several options were considered. The main ones were planting, collecting water for livestock and agriculture and finally installing exclosures. Agro-forestry plantations were carried out with different species, particularly the genus Atriplex, Medicago and Opuntia. Small hydraulic entities were also built to increase the planted area. The exclosures were established on millions of acres. We discuss the relevance and success rate of these works. The economics and biological impacts (biodiversity, production) are assessed. As a result, the government's strategies are not coherent and sometimes seem at odds with the objectives of combating desertification. Worse yet, in some

Transgenic tobacco plants expressing atzA exhibit resistance and strong ability to degrade atrazine.

PubMed

Wang, Huizhuan; Chen, Xiwen; Xing, Xuguang; Hao, Xiaohua; Chen, Defu

2010-12-01

Atrazine chlorohydrolase (AtzA) catalyzes hydrolytic dechlorination and can be used in detoxification of atrazine, a herbicide widely employed in the control of broadleaf weeds. In this study, to investigate the potential use of transgenic tobacco plants for phytoremediation of atrazine, atzA genes from Pseudomonas sp. strain ADP and Arthrobacter strain AD1 were transferred into tobacco. Three and four transgenic lines, expressing atzA-ADP and atzA-AD1, respectively, were produced by Agrobacterium-mediated transformation. Molecular characterization including PCR, RT-PCR and Southern blot revealed that atzA was inserted into the tobacco genome and stably inherited by and expressed in the progenies. Seeds of the T(1) transgenic lines had a higher germination percentage and longer roots than the untransformed plants in the presence of 40-150 mg/l atrazine. The T(2) transgenic lines grew taller, gained more dry biomass, and had higher total chlorophyll content than the untransformed plants after growing in soil containing 1 or 2 mg/kg atrazine for 90 days. No atrazine residue remained in the soil in which the T(2) transgenic lines were grown (except 401), while, in the case of the untransformed plants, 0.91 mg (81.3%) and 1.66 mg (74.1%) of the atrazine still remained in the soil containing 1 and 2 mg/kg of atrazine, respectively, indicating that the transgenic lines could degrade atrazine effectively. The transgenic tobacco lines developed could be useful for phytoremediation of atrazine-contaminated soil and water.

Microbial Degradation of Lobster Shells to Extract Chitin Derivatives for Plant Disease Management.

PubMed

Ilangumaran, Gayathri; Stratton, Glenn; Ravichandran, Sridhar; Shukla, Pushp S; Potin, Philippe; Asiedu, Samuel; Prithiviraj, Balakrishnan

2017-01-01

Biodegradation of lobster shells by chitinolytic microorganisms are an environment safe approach to utilize lobster processing wastes for chitin derivation. In this study, we report degradation activities of two microbes, "S223" and "S224" isolated from soil samples that had the highest rate of deproteinization, demineralization and chitinolysis among ten microorganisms screened. Isolates S223 and S224 had 27.3 and 103.8 protease units mg -1 protein and 12.3 and 11.2 μg ml -1 of calcium in their samples, respectively, after 1 week of incubation with raw lobster shells. Further, S223 contained 23.8 μg ml -1 of N -Acetylglucosamine on day 3, while S224 had 27.3 μg ml -1 on day 7 of incubation with chitin. Morphological observations and 16S rDNA sequencing suggested both the isolates were Streptomyces . The culture conditions were optimized for efficient degradation of lobster shells and chitinase (∼30 kDa) was purified from crude extract by affinity chromatography. The digested lobster shell extracts induced disease resistance in Arabidopsis by induction of defense related genes ( PR1 > 500-fold, PDF1.2 > 40-fold) upon Pseudomonas syringae and Botrytis cinerea infection. The study suggests that soil microbes aid in sustainable bioconversion of lobster shells and extraction of chitin derivatives that could be applied in plant protection.

Microbial Degradation of Lobster Shells to Extract Chitin Derivatives for Plant Disease Management

PubMed Central

Ilangumaran, Gayathri; Stratton, Glenn; Ravichandran, Sridhar; Shukla, Pushp S.; Potin, Philippe; Asiedu, Samuel; Prithiviraj, Balakrishnan

2017-01-01

Biodegradation of lobster shells by chitinolytic microorganisms are an environment safe approach to utilize lobster processing wastes for chitin derivation. In this study, we report degradation activities of two microbes, “S223” and “S224” isolated from soil samples that had the highest rate of deproteinization, demineralization and chitinolysis among ten microorganisms screened. Isolates S223 and S224 had 27.3 and 103.8 protease units mg-1 protein and 12.3 and 11.2 μg ml-1 of calcium in their samples, respectively, after 1 week of incubation with raw lobster shells. Further, S223 contained 23.8 μg ml-1 of N-Acetylglucosamine on day 3, while S224 had 27.3 μg ml-1 on day 7 of incubation with chitin. Morphological observations and 16S rDNA sequencing suggested both the isolates were Streptomyces. The culture conditions were optimized for efficient degradation of lobster shells and chitinase (∼30 kDa) was purified from crude extract by affinity chromatography. The digested lobster shell extracts induced disease resistance in Arabidopsis by induction of defense related genes (PR1 > 500-fold, PDF1.2 > 40-fold) upon Pseudomonas syringae and Botrytis cinerea infection. The study suggests that soil microbes aid in sustainable bioconversion of lobster shells and extraction of chitin derivatives that could be applied in plant protection. PMID:28529501

Reestablishing understory plants in overused wooded areas of Maryland state parks

Treesearch

Silas Little; John J. Mohr

1979-01-01

In four overused areas, the treatments of small plots were fencing, scarifying the soil, and mulching; fencing and mulching plus planting of shrubs, herbaceous plants, or greenbrier with shrubs or holly. After 3 years, soil compaction was two to four times as great in check plots as in treated plots. Understory cover varied with conditions, but because of volunteer...

An ethnobotanical survey of medicinal plants used by the people in Nhema communal area, Zimbabwe.

PubMed

Maroyi, Alfred

2011-06-22

This study documented the pharmaceutical importance of plant resources in Nhema communal area, particularly the significance of medicinal plants in primary healthcare. This is reflected in the great diversity of plants used for medical purposes as well as in their wide range of medicinal applications. Such rich ethnobotanical knowledge and repository of medicinal plants reinforces the need for an evaluation of their biological activity as a basis for developing future medicines. In order to document information on medicinal plants used for primary health care and to maximize the collection of indigenous knowledge in Nhema communal area, nine traditional healers were identified using the Participatory Rapid Appraisal (PRA) approach. Data was collected through open-ended interviews with traditional healers, between January and May 2008. A total of 61 plant species representing 45 genera and 28 families were found to be commonly used in the treatment of 34 different human health problems. More than a third of the plant species were used for diarrhoea, which is a prevalent disease in the study area. The root was the most commonly used plant part while decoction was the most common method of traditional drug preparation. Nhema communal area in the Midlands province, Zimbabwe is endowed with a strong culture of herbal medicine usage for primary healthcare. This is reflected in the number of medicinal plants used and the human ailments they treat. This preservation of indigenous knowledge is due to continued reliance on wild plant resources for primary healthcare by the local community. Deforestation and unsustainable rates of plant use are a serious threat on continued utilization of plant resources for primary healthcare. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Ascorbate degradation in tomato leads to accumulation of oxalate, threonate and oxalyl threonate.

PubMed

Truffault, Vincent; Fry, Stephen C; Stevens, Rebecca G; Gautier, Hélène

2017-03-01

Ascorbate content in plants is controlled by its synthesis from carbohydrates, recycling of the oxidized forms and degradation. Of these pathways, ascorbate degradation is the least studied and represents a lack of knowledge that could impair improvement of ascorbate content in fruits and vegetables as degradation is non-reversible and leads to a depletion of the ascorbate pool. The present study revealed the nature of degradation products using [ 14 C]ascorbate labelling in tomato, a model plant for fleshy fruits; oxalate and threonate are accumulated in leaves, as is oxalyl threonate. Carboxypentonates coming from diketogulonate degradation were detected in relatively insoluble (cell wall-rich) leaf material. No [ 14 C]tartaric acid was found in tomato leaves. Ascorbate degradation was stimulated by darkness, and the degradation rate was evaluated at 63% of the ascorbate pool per day, a percentage that was constant and independent of the initial ascorbate or dehydroascorbic acid concentration over periods of 24 h or more. Furthermore, degradation could be partially affected by the ascorbate recycling pathway, as lines under-expressing monodehydroascorbate reductase showed a slight decrease in degradation product accumulation. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Kobresia pygmaea pasture degradation and its response to increasing N deposition

NASA Astrophysics Data System (ADS)

Liu, Shibin; Schleuss, Per-Marten; Kuzyakov, Yakov

2016-04-01

Kobresia pygmaea is a dominant plant species on the Tibetan Plateau covering ca. one fifth of the total area. Severe degradation by overgrazing is ongoing at K. pygmaea pastures in recent decades. Nitrogen (N) deposition is also increasingly exacerbated across the Tibetan Plateau. Up to now the response of K. pygmaea pastures with increasing degradation to N deposition is unclear. We aimed at: (1) evaluating the effect of pasture degradation on carbon (C) and N contents of soil, root, microbial biomass and leachate, (2) determining N allocation to plant, soil and microbial biomass after N addition and (3) making an estimation of N storage and loss in Kobresia pasture. We used three Kobresia root mat types varying in their degradation stages: (1) living root mats, (2) dying root mats and (3) dead root mats. We also added two levels of 15NH415NO3 solution to simulate N deposition (control: 2.5 kg N/ha; deposition 50.9 kg N/ha) and traced the 15N in the soil-plant system. Leaching of NH4+, NO3- and DON were detected by homogeneously adding distilled water to each sample and collecting the leachate afterwards. Total N content lost by leaching increased 6.5 times following the degradation from living to dead root mats. This indicated that living Kobresia effectively decreased N loss from leaching due to N uptake by plants. The microbial biomass C to N (MBC/MBN) ratio narrowed from 10.2 to 7.5 and then to 5.0 for living, dying and dead root mats, respectively. This shows the degradation K. pygmaea shift the ecosystem from a N-limited to a C-limited status for microbes. Nitrogen addition increased above-ground plant biomass (AGB) as well as its total N content in living root mat while MBC and MBN were not affected. This shows K. pygmaea is more sensitive to N addition than microorganisms. N allocation (% of total N added) by AGB, below-ground plant biomass and soil in living root mats were 22.1%, 22.7% and 17.6%, respectively. No significant effect between these

Degradation in landscape matrix has diverse impacts on diversity in protected areas

PubMed Central

Brotons, Lluís; Rajasärkkä, Ari; Tornberg, Risto

2017-01-01

Introduction A main goal of protected areas is to maintain species diversity and the integrity of biological assemblages. Intensifying land use in the matrix surrounding protected areas creates a challenge for biodiversity conservation. Earlier studies have mainly focused on taxonomic diversity within protected areas. However, functional and especially phylogenetic diversities are less studied phenomena, especially with respect to the impacts of the matrix that surrounds protected areas. Phylogenetic diversity refers to the range of evolutionary lineages, the maintenance of which ensures that future evolutionary potential is safeguarded. Functional diversity refers to the range of ecological roles that members of a community perform. For ecosystem functioning and long-term resilience, they are at least as important as taxonomic diversity. Aim We studied how the characteristics of protected areas and land use intensity in the surrounding matrix affect the diversity of bird communities in protected boreal forests. We used line-transect count and land-cover data from 91 forest reserves in Northern Finland, and land-cover data from buffer zones surrounding these reserves. We studied if habitat diversity and productivity inside protected areas, and intensity of forest management in the matrix have consistent effects on taxonomic, functional and phylogenetic diversities, and community specialization. Results We found that habitat diversity and productivity inside protected areas have strong effects on all diversity metrics, but matrix effects were inconsistent. The proportion of old forest in the matrix, reflecting low intensity forest management, had positive effects on community specialization. Interestingly, functional diversity increased with increasing logging intensity in the matrix. Conclusions Our results indicate that boreal forest reserves are not able to maintain their species composition and abundances if embedded in a severely degraded matrix. Our study also

Studying the organization of genes encoding plant cell wall degrading enzymes in Chrysomela tremula provides insights into a leaf beetle genome.

PubMed

Pauchet, Y; Saski, C A; Feltus, F A; Luyten, I; Quesneville, H; Heckel, D G

2014-06-01

The ability of herbivorous beetles from the superfamilies Chrysomeloidea and Curculionoidea to degrade plant cell wall polysaccharides has only recently begun to be appreciated. The presence of plant cell wall degrading enzymes (PCWDEs) in the beetle's digestive tract makes this degradation possible. Sequences encoding these beetle-derived PCWDEs were originally identified from transcriptomes and strikingly resemble those of saprophytic and phytopathogenic microorganisms, raising questions about their origin; e.g. are they insect- or microorganism-derived? To demonstrate unambiguously that the genes encoding PCWDEs found in beetle transcriptomes are indeed of insect origin, we generated a bacterial artificial chromosome library from the genome of the leaf beetle Chrysomela tremula, containing 18 432 clones with an average size of 143 kb. After hybridizing this library with probes derived from 12 C. tremula PCWDE-encoding genes and sequencing the positive clones, we demonstrated that the latter genes are encoded by the insect's genome and are surrounded by genes possessing orthologues in the genome of Tribolium castaneum as well as in three other beetle genomes. Our analyses showed that although the level of overall synteny between C. tremula and T. castaneum seems high, the degree of microsynteny between both species is relatively low, in contrast to the more closely related Colorado potato beetle. © 2014 The Royal Entomological Society.

The soil biota composition along a progressive succession of secondary vegetation in a karst area.

PubMed

Zhao, Jie; Li, Shengping; He, Xunyang; Liu, Lu; Wang, Kelin

2014-01-01

Karst ecosystems are fragile and are in many regions degraded by anthropogenic activities. Current management of degraded karst areas focuses on aboveground vegetation succession or recovery and aims at establishing a forest ecosystem. Whether progressive succession of vegetation in karst areas is accompanied by establishment of soil biota is poorly understood. In the present study, soil microbial and nematode communities, as well as soil physico-chemical properties were studied along a progressive succession of secondary vegetation (from grassland to shrubland to forest) in a karst area in southwest China. Microbial biomass, nematode density, ratio of fungal to bacterial biomass, nematode structure index, and nematode enrichment index decreased with the secondary succession in the plant community. Overall, the results indicated a pattern of declines in soil biota abundance and food web complexity that was associated with a decrease in soil pH and a decrease in soil organic carbon content with the progressive secondary succession of the plant community. Our findings suggest that soil biota amendment is necessary during karst ecosystem restoration and establishment and management of grasslands may be feasible in karst areas.

GIS-based evaluation and spatial distribution characteristics of land degradation in Bijiang watershed.

PubMed

Zhao, Xiaoqing; Dai, Jinhua; Wang, Jianping

2013-01-01

Land degradation is one of the significant issues the human beings are confronted with, which has become a bottleneck of restricting the sustainable development of the regional society and economy. In order to ascertain the root causes contributed to the land degradation and characteristics of land degradation, Bijiang watershed, the most important Lead-Zinc mine area of Lanping county of Yunnan Province, was selected as the study area. One evaluation index system for land degradation that consists of 5 single factors(water-soil erosion intensity, geological disaster risk, cultivation intensity of arable land, pollution of heavy metals in soil and biodiversity deterioration) was established and 13 indicators were chosen, and the entropy method was adopted to assign weights to each single factor. By using the tools of Geographic Information System (GIS), the land degradation degree was evaluated and one spatial distribution map for land degradation was accomplished. In this study, the land of the whole watershed was divided into 4 types, including extremely-severe degradation area, severely-degraded area, moderately-degraded area and slightly-degraded area, and some solutions for ecological restoration and rehabilitation were also put forward in this study. The study results indicated that: (1) Water-soil erosion intension and pollution of heavy metals in soil have made greater contribution to the comprehensive land degradation in Bijiang watershed; (2) There is an apparent difference regarding land degradation degree in Bijiang watershed. The moderately-degraded area accounts for the most part in the region, which covers 79.66% of the whole watershed. The severely-degraded area accounts for 15.98% and the slightly-degraded regions and extremely severe degradation area accounts for 1.08% and 3.28% respectively; (3) There is an evident regularity of spatial distribution in land degradation in Bijiang watershed. The moderately-degraded areas mainly distribute in the

Riparian restoration in the Southwest: Species selection, propagation, planting methods, and case studies

Treesearch

David Dreesen; John Harrington; Tom Subirge; Pete Stewart; Greg Fenchel

2002-01-01

Riparian plant communities, though small in overall area, are among the most valuable natural areas in the Southwest. The causes of degradation of southwestern riparian zones range from excessive cattle and elk grazing in montane watersheds to invasive woody exotic species and lack of natural flooding in the cottonwood forests, "bosque," of low elevation...

Massive lateral transfer of genes encoding plant cell wall-degrading enzymes to the mycoparasitic fungus Trichoderma from its plant-associated hosts

PubMed Central

Chenthamara, Komal; Zhang, Jian; Atanasova, Lea; Yang, Dongqing; Miao, Youzhi; Grujic, Marica; Pourmehdi, Shadi; Pretzer, Carina; Kopchinskiy, Alexey G.; Hundley, Hope; Wang, Mei; Aerts, Andrea; Salamov, Asaf; Lipzen, Anna; Barry, Kerrie; Grigoriev, Igor V.; Shen, Qirong; Kubicek, Christian P.

2018-01-01

Unlike most other fungi, molds of the genus Trichoderma (Hypocreales, Ascomycota) are aggressive parasites of other fungi and efficient decomposers of plant biomass. Although nutritional shifts are common among hypocrealean fungi, there are no examples of such broad substrate versatility as that observed in Trichoderma. A phylogenomic analysis of 23 hypocrealean fungi (including nine Trichoderma spp. and the related Escovopsis weberi) revealed that the genus Trichoderma has evolved from an ancestor with limited cellulolytic capability that fed on either fungi or arthropods. The evolutionary analysis of Trichoderma genes encoding plant cell wall-degrading carbohydrate-active enzymes and auxiliary proteins (pcwdCAZome, 122 gene families) based on a gene tree / species tree reconciliation demonstrated that the formation of the genus was accompanied by an unprecedented extent of lateral gene transfer (LGT). Nearly one-half of the genes in Trichoderma pcwdCAZome (41%) were obtained via LGT from plant-associated filamentous fungi belonging to different classes of Ascomycota, while no LGT was observed from other potential donors. In addition to the ability to feed on unrelated fungi (such as Basidiomycota), we also showed that Trichoderma is capable of endoparasitism on a broad range of Ascomycota, including extant LGT donors. This phenomenon was not observed in E. weberi and rarely in other mycoparasitic hypocrealean fungi. Thus, our study suggests that LGT is linked to the ability of Trichoderma to parasitize taxonomically related fungi (up to adelphoparasitism in strict sense). This may have allowed primarily mycotrophic Trichoderma fungi to evolve into decomposers of plant biomass. PMID:29630596

Solar CPC pilot plant photocatalytic degradation of bisphenol A in waters and wastewaters using suspended and supported-TiO2. Influence of photogenerated species.

PubMed

Saggioro, Enrico Mendes; Oliveira, Anabela Sousa; Pavesi, Thelma; Tototzintle, Margarita Jiménez; Maldonado, Manuel Ignacio; Correia, Fábio Verissimo; Moreira, Josino Costa

2014-11-01

Photocatalytic degradation of bisphenol A (BPA) in waters and wastewaters in the presence of titanium dioxide (TiO2) was performed under different conditions. Suspensions of the TiO2 were used to compare the degradation efficiency of BPA (20 mg L(-1)) in batch and compound parabolic collector (CPC) reactors. A TiO2 catalyst supported on glass spheres was prepared (sol-gel method) and used in a CPC solar pilot plant for the photodegradation of BPA (100 μg L(-1)). The influence of OH·, O2 (·-), and h (+) on the BPA degradation were evaluated. The radicals OH· and O2 (·-) were proved to be the main species involved on BPA photodegradation. Total organic carbon (TOC) and carboxylic acids were determined to evaluate the BPA mineralization during the photodegradation process. Some toxicological effects of BPA and its photoproducts on Eisenia andrei earthworms were evaluated. The results show that the optimal concentration of suspended TiO2 to degrade BPA in batch or CPC reactors was 0.1 g L(-1). According to biological tests, the BPA LC50 in 24 h for E. andrei was of 1.7 × 10(-2) mg cm(-2). The photocatalytic degradation of BPA mediated by TiO2 supported on glass spheres suffered strong influence of the water matrix. On real municipal wastewater treatment plant (MWWTP) secondary effluent, 30 % of BPA remains in solution; nevertheless, the method has the enormous advantage since it eliminates the need of catalyst removal step, reducing the cost of treatment.

Impact of soil water regime on degradation and plant uptake behaviour of the herbicide isoproturon in different soil types.

PubMed

Grundmann, Sabine; Doerfler, Ulrike; Munch, Jean Charles; Ruth, Bernhard; Schroll, Reiner

2011-03-01

The environmental fate of the worldwide used herbicide isoproturon was studied in four different, undisturbed lysimeters in the temperate zone of Middle Europe. To exclude climatic effects due to location, soils were collected at different regions in southern Germany and analyzed at a lysimeter station under identical environmental conditions. (14)C-isoproturon mineralization varied between 2.59% and 57.95% in the different soils. Barley plants grown on these lysimeters accumulated (14)C-pesticide residues from soil in partially high amounts and emitted (14)CO(2) in an extent between 2.01% and 13.65% of the applied (14)C-pesticide. Plant uptake and (14)CO(2) emissions from plants were inversely linked to the mineralization of the pesticide in the various soils: High isoproturon mineralization in soil resulted in low plant uptake whereas low isoproturon mineralization in soil resulted in high uptake of isoproturon residues in crop plants and high (14)CO(2) emission from plant surfaces. The soil water regime was identified as an essential factor that regulates degradation and plant uptake of isoproturon whereby the intensity of the impact of this factor is strongly dependent on the soil type. Copyright © 2010 Elsevier Ltd. All rights reserved.

Native grass seeding and forb planting establishment in a degraded oak savanna plant community in the Coast Range foothills of western Oregon.

Treesearch

Nan Vance; Andrew Neill; Frank Morton

2006-01-01

After a dense stand of conifers encroaching on an oak savanna/meadow was removed, exotic forbs and grasses quickly populated the newly disturbed area. Establishing desirable native grasses and forbs that contribute to native plant diversity and complete with exotic species could aid in restoring this oak savanna plant community. Two experiments were conducted over time...

Glyphosate degradation in glyphosate-resistant and -susceptible crops and weeds.

PubMed

Duke, Stephen O

2011-06-08

High levels of aminomethylphosphonic acid (AMPA), the main glyphosate metabolite, have been found in glyphosate-treated, glyphosate-resistant (GR) soybean, apparently due to plant glyphosate oxidoreductase (GOX)-like activity. AMPA is mildly phytotoxic, and under some conditions the AMPA accumulating in GR soybean correlates with glyphosate-caused phytotoxicity. A bacterial GOX is used in GR canola, and an altered bacterial glyphosate N-acetyltransferase is planned for a new generation of GR crops. In some weed species, glyphosate degradation could contribute to natural resistance. Neither an isolated plant GOX enzyme nor a gene for it has yet been reported in plants. Gene mutation or amplification of plant genes for GOX-like enzyme activity or horizontal transfer of microbial genes from glyphosate-degrading enzymes could produce GR weeds. Yet, there is no evidence that metabolic degradation plays a significant role in evolved resistance to glyphosate. This is unexpected, considering the extreme selection pressure for evolution of glyphosate resistance in weeds and the difficulty in plants of evolving glyphosate resistance via other mechanisms.

Coal mining activities change plant community structure due to air pollution and soil degradation.

PubMed

Pandey, Bhanu; Agrawal, Madhoolika; Singh, Siddharth

2014-10-01

The aim of this study was to investigate the effects of coal mining activities on the community structures of woody and herbaceous plants. The response of individual plants of community to defilement caused by coal mining was also assessed. Air monitoring, soil physico-chemical and phytosociological analyses were carried around Jharia coalfield (JCF) and Raniganj coalfield. The importance value index of sensitive species minified and those of tolerant species enhanced with increasing pollution load and altered soil quality around coal mining areas. Although the species richness of woody and herbaceous plants decreased with higher pollution load, a large number of species acclimatized to the stress caused by the coal mining activities. Woody plant community at JCF was more affected by coal mining than herbaceous community. Canonical correspondence analysis revealed that structure of herbaceous community was mainly driven by soil total organic carbon, soil nitrogen, whereas woody layer community was influenced by sulphur dioxide in ambient air, soil sulphate and soil phosphorus. The changes in species diversity observed at mining areas indicated an increase in the proportion of resistant herbs and grasses showing a tendency towards a definite selection strategy of ecosystem in response to air pollution and altered soil characteristics.

Flow Field Analysis of Fish Farm and Planting Area in Floodplain during Flood

NASA Astrophysics Data System (ADS)

Wu, M.; Tan, H. N.; Lo, W. C.; Tsai, C. T.

2017-12-01

Fish farms constructing and crops planting is common in floodplain in Taiwan. The physiographic soil erosion-deposition (PSED) model was applied to simulate the sediment yield, the runoff, and sediment transport rate of the river watershed corresponding to one-day rainstorms of the return periods of 25, 50, and 100 year. The variation of flow field in the river sections could be simulated by utilizing the alluvial river-movable bed two dimensional (ARMB-2D) model. The results reveal that the tendency of river discharge, sediment deposition and erosion obtained from these two models is agreeable by calibration and verification. The water flow affected by fish farms and planting areas in floodplain during flood was analyzed. Lastly, based on the simulation results obtained from the PESD and ARMB-2D models for one-day rainstorms of the return periods of 25, 50, and 100 year, the illegal fish farms and planting area with severe variations of river flow and affected he capability for flood conveyance will be referred to as the demolishing-to-be areas. We could also suggest the management strategy of application for fish farms constructing and crops planting in river areas by incorporating the ability of our model to provide information of river flow to enhance the flood conveyance.

An aerial radiological survey of the Robert Emmett Ginna Nuclear Power Plant and surrounding area, Ontario, New York

DOE Office of Scientific and Technical Information (OSTI.GOV)

Proctor, A.E.

1997-06-01

Terrestrial radioactivity surrounding the Robert Emmett Ginna Nuclear Power Plant was measured using aerial radiological surveying techniques. The purpose of this survey was to document exposure rates near the plant and to identify unexpected, man-made radiation sources within the survey area. The surveyed area included land areas within a three-mile radius of the plant site. Data were acquired using an airborne detection system that employed sodium iodide, thallium-activated detectors. Exposure-rate and photopeak counts were computed from these data and plotted on aerial photographs of the survey area. Several ground-based exposure measurements were made for comparison with the aerial survey results.more » Exposure rates in the area surrounding the plant site varied from 6 to 10 microroentgens per hour. Man-made radiation (cobalt-60 within the plant site and cesium-1 37 directly over the reactor) was found at the plant site. In addition, small areas of suspected cesium-137 activity were found within the survey areas. Other than these small sites, the survey area was free of man-made radioac- tivity.« less

Degradation of N-heterocyclic indole by a novel endophytic fungus Phomopsis liquidambari.

PubMed

Chen, Yan; Xie, Xing-Guang; Ren, Cheng-Gang; Dai, Chuan-Chao

2013-02-01

A broad-spectrum endophytic Phomopsis liquidambari, was used to degrade environmental pollutant indole. In the condition of using indole as sole carbon and nitrogen source, the optimum concentration of indole supplied was determined to be 100 mg L(-1), with 41.7% ratio of indole degradation within 120 h. Exogenous addition of plant litter significantly increased indole degradation to 99.1% within 60 h. Indole oxidation to oxindole and isatin were the key steps limiting indole degradation. Plant litter addition induced fungus to produce laccase and LiP to non-specific oxidize indole. The results of fungal metabolites pathway through HPLC-MS and NMR analysis showed that indole was firstly oxidized to oxindole and isatin, and deoxidated to indolenie-2-dione, then hydroxylated to 2-dioxindole, which pyridine ring were cleaved through C-N position and changed to 2-aminobenzoic acid. Such metabolic pathway was similar with bacterial degradation of indole-3-acetic acid in plant. Copyright © 2012 Elsevier Ltd. All rights reserved.

Native plants and communities and exotic plants within the Hoosier-Shawnee ecological assessment area

Treesearch

Steven D. Olson; Michael A. Homoya; Elizabeth L. Shimp

2004-01-01

The diverse natural communities in the Hoosier-Shawnee Ecological Assessment Area include forests, barrens, cliffs, wetlands, and streams. Communities are described based on their dominant and characteristic canopy and understory species as well as abiotic factors. An assessment of the global and state status of plant species is presented; the viability of over 360...

Novel bacterial consortia isolated from plastic garbage processing areas demonstrated enhanced degradation for low density polyethylene.

PubMed

Skariyachan, Sinosh; Manjunatha, Vishal; Sultana, Subiya; Jois, Chandana; Bai, Vidya; Vasist, Kiran S

2016-09-01

This study aimed to formulate novel microbial consortia isolated from plastic garbage processing areas and thereby devise an eco-friendly approach for enhanced degradation of low-density polyethylene (LDPE). The LDPE degrading bacteria were screened and microbiologically characterized. The best isolates were formulated as bacterial consortia, and degradation efficiency was compared with the consortia formulated using known isolates obtained from the Microbial Culture Collection Centre (MTCC). The degradation products were analyzed by FTIR, GC-FID, tensile strength, and SEM. The bacterial consortia were characterized by 16S ribosomal DNA (rDNA) sequencing. The formulated bacterial consortia demonstrated 81 ± 4 and 38 ± 3 % of weight reduction for LDPE strips and LDPE pellets, respectively, over a period of 120 days. However, the consortia formulated by MTCC strains demonstrated 49 ± 4 and 20 ± 2 % of weight reduction for LDPE strips and pellets, respectively, for the same period. Furthermore, the three isolates in its individual application exhibited 70 ± 4, 68 ± 4, and 64 ± 4 % weight reduction for LDPE strips and 21 ± 2, 28 ± 2, 24 ± 2 % weight reduction for LDPE pellets over a period of 120 days (p < 0.05). The end product analysis showed structural changes and formation of bacterial film on degraded LDPE strips. The 16S rDNA characterization of bacterial consortia revealed that these organisms were novel strains and designated as Enterobacter sp. bengaluru-btdsce01, Enterobacter sp. bengaluru-btdsce02, and Pantoea sp. bengaluru-btdsce03. The current study thus suggests that industrial scale-up of these microbial consortia probably provides better insights for waste management of LDPE and similar types of plastic garbage.

Seismic Fragility Analysis of a Condensate Storage Tank with Age-Related Degradations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nie, J.; Braverman, J.; Hofmayer, C

2011-04-01

The Korea Atomic Energy Research Institute (KAERI) is conducting a five-year research project to develop a realistic seismic risk evaluation system which includes the consideration of aging of structures and components in nuclear power plants (NPPs). The KAERI research project includes three specific areas that are essential to seismic probabilistic risk assessment (PRA): (1) probabilistic seismic hazard analysis, (2) seismic fragility analysis including the effects of aging, and (3) a plant seismic risk analysis. Since 2007, Brookhaven National Laboratory (BNL) has entered into a collaboration agreement with KAERI to support its development of seismic capability evaluation technology for degraded structuresmore » and components. The collaborative research effort is intended to continue over a five year period. The goal of this collaboration endeavor is to assist KAERI to develop seismic fragility analysis methods that consider the potential effects of age-related degradation of structures, systems, and components (SSCs). The research results of this multi-year collaboration will be utilized as input to seismic PRAs. This report describes the research effort performed by BNL for the Year 4 scope of work. This report was developed as an update to the Year 3 report by incorporating a major supplement to the Year 3 fragility analysis. In the Year 4 research scope, an additional study was carried out to consider an additional degradation scenario, in which the three basic degradation scenarios, i.e., degraded tank shell, degraded anchor bolts, and cracked anchorage concrete, are combined in a non-perfect correlation manner. A representative operational water level is used for this effort. Building on the same CDFM procedure implemented for the Year 3 Tasks, a simulation method was applied using optimum Latin Hypercube samples to characterize the deterioration behavior of the fragility capacity as a function of age-related degradations. The results are summarized in

Neutron activation analysis of thermal power plant ash and surrounding area soils.

PubMed

Al-Masri, M S; Haddad, Kh; Alsomel, N; Sarhil, A

2015-08-01

Elemental concentrations of As, Cd, Co, Cr, Fe, Hg, Mo, Ni, Se, and Zn have been determined in fly and bottom ash collected from Syrian power plants fired by heavy oil and natural gas using instrumental neutron activation analysis. The results showed that all elements were more concentrated in fly ash than in the fly ash; there was a clear increasing trend of the elemental concentrations in the fly ash along the flue gas pathway. The annual emission of elements was estimated. Elemental concentrations were higher inside the campus area than in surrounding areas, and the lowest values were found in natural-gas-fired power plant. In addition, the levels have decreased as the distance from power plant campus increases. However, the levels in the surrounding villages were within the Syrian standard for agriculture soil.

Temporal transcriptome analysis of the white-rot fungus Obba rivulosa shows expression of a constitutive set of plant cell wall degradation targeted genes during growth on solid spruce wood.

PubMed

Marinović, Mila; Aguilar-Pontes, Maria Victoria; Zhou, Miaomiao; Miettinen, Otto; de Vries, Ronald P; Mäkelä, Miia R; Hildén, Kristiina

2018-03-01

The basidiomycete white-rot fungus Obba rivulosa, a close relative of Gelatoporia (Ceriporiopsis) subvermispora, is an efficient degrader of softwood. The dikaryotic O. rivulosa strain T241i (FBCC949) has been shown to selectively remove lignin from spruce wood prior to depolymerization of plant cell wall polysaccharides, thus possessing potential in biotechnological applications such as pretreatment of wood in pulp and paper industry. In this work, we studied the time-course of the conversion of spruce by the genome-sequenced monokaryotic O. rivulosa strain 3A-2, which is derived from the dikaryon T241i, to get insight into transcriptome level changes during prolonged solid state cultivation. During 8-week cultivation, O. rivulosa expressed a constitutive set of genes encoding putative plant cell wall degrading enzymes. High level of expression of the genes targeted towards all plant cell wall polymers was detected at 2-week time point, after which majority of the genes showed reduced expression. This implicated non-selective degradation of lignin by the O. rivulosa monokaryon and suggests high variation between mono- and dikaryotic strains of the white-rot fungi with respect to their abilities to convert plant cell wall polymers. Copyright © 2017 Elsevier Inc. All rights reserved.

Potential for Microbial Degradation of cis-Dichloroethene and Vinyl Chloride in Streambed Sediment at the U.S. Department of Energy, Kansas City Plant, Missouri, 2008

USGS Publications Warehouse

Bradley, Paul M.

2009-01-01

A series of carbon-14 (14C) radiotracer-based microcosm experiments was conducted to assess the mechanisms and products of degradation of cis-dichloroethene (cis-DCE) and vinyl chloride (VC) in streambed sediments at the U.S. Department of Energy, Kansas City Plant in Kansas City, Missouri. The focus of the investigation was the potential for biotic and abiotic cis-DCE and VC degradation in surficial and underlying hyporheic sediment from the Blue River and its tributaries, Indian Creek and Boone Creek. Substantial degradation of [1,2-14C] cis-DCE and [1,2-14C] VC to 14C-carbon dioxide (14CO2) was observed in all viable surficial sediment microcosms prepared under oxic conditions. No significant accumulation of reductive dechlorination products was observed under these oxic incubation conditions. The results indicate that microbial mineralization processes involving direct oxidation or co-metabolic oxidation are the primary mechanisms of cis-DCE and VC biodegradation in oxic stream sediment at the Kansas City Plant. Substantial mineralization of [1,2-14C] VC also was observed in all viable surficial sediment microcosms incubated in the absence of detectable oxygen (dissolved oxygen concentrations less than 25 micrograms per liter). In general, the accumulation of mineralization products (14CO2 and 14C-methane [14CH4]) predominated with only trace-level detection of the reductive dechlorination product, 14C-ethene. In contrast, microbial degradation of [1,2-14C] cis-DCE by reductive dechlorination or mineralization was not significant in the absence of detectable oxygen. The potential for [1,2-14C] VC biodegradation also was significant in sediments from the deeper hyporheic zones under oxic conditions and in the absence of detectable oxygen. In this study, microbial degradation of [1,2-14C] cis-DCE was not significant in hyporheic sediment treatments under either oxygen condition. Taken together, the results indicate that microbial mineralization processes in

Individual-Based Ant-Plant Networks: Diurnal-Nocturnal Structure and Species-Area Relationship

PubMed Central

Dáttilo, Wesley; Fagundes, Roberth; Gurka, Carlos A. Q.; Silva, Mara S. A.; Vieira, Marisa C. L.; Izzo, Thiago J.; Díaz-Castelazo, Cecília; Del-Claro, Kleber; Rico-Gray, Victor

2014-01-01

Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available) in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants’ composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this “night-turnover” suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night) at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences. PMID:24918750

Savannah River Plant engineering and design history. Volume 4: 300/700 Areas & general services and facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1957-01-01

The primary function of the 300 Area is the production and preparation of the fuel and target elements required for the 100 Area production reactors. Uranium slugs and lithium-aluminium alloy control and blanket rods are prepared in separate structures. Other facilities include a test pile, a physics assembly laboratory, an office and change house, an electrical substation, and various service facilities such as rail lines, roads, sewers, steam and water distribution lines, etc. The 700 Area contains housing and facilities for plant management, general plant services, and certain technical activities. The technical buildings include the Main Technical Laboratory, the Wastemore » Concentration Building, the Health Physics Headquarters, and the Health Physics Calibration building. Sections of this report describe the following: development of the 300-M Area; selection and description of process; design of main facilities of the 300 Area; development of the 700-A Area; design of the main facilities of the 700 Area; and general services and facilities, including transportation, plant protection, waste disposal and drainage, site work, pilot plants, storage, and furniture and fixtures.« less

Combining endangered plants and animals as surrogates to identify priority conservation areas in Yunnan, China

PubMed Central

Yang, Feiling; Hu, Jinming; Wu, Ruidong

2016-01-01

Suitable surrogates are critical for identifying optimal priority conservation areas (PCAs) to protect regional biodiversity. This study explored the efficiency of using endangered plants and animals as surrogates for identifying PCAs at the county level in Yunnan, southwest China. We ran the Dobson algorithm under three surrogate scenarios at 75% and 100% conservation levels and identified four types of PCAs. Assessment of the protection efficiencies of the four types of PCAs showed that endangered plants had higher surrogacy values than endangered animals but that the two were not substitutable; coupled endangered plants and animals as surrogates yielded a higher surrogacy value than endangered plants or animals as surrogates; the plant-animal priority areas (PAPAs) was the optimal among the four types of PCAs for conserving both endangered plants and animals in Yunnan. PAPAs could well represent overall species diversity distribution patterns and overlap with critical biogeographical regions in Yunnan. Fourteen priority units in PAPAs should be urgently considered as optimizing Yunnan’s protected area system. The spatial pattern of PAPAs at the 100% conservation level could be conceptualized into three connected conservation belts, providing a valuable reference for optimizing the layout of the in situ protected area system in Yunnan. PMID:27538537

Combining endangered plants and animals as surrogates to identify priority conservation areas in Yunnan, China

NASA Astrophysics Data System (ADS)

Yang, Feiling; Hu, Jinming; Wu, Ruidong

2016-08-01

Suitable surrogates are critical for identifying optimal priority conservation areas (PCAs) to protect regional biodiversity. This study explored the efficiency of using endangered plants and animals as surrogates for identifying PCAs at the county level in Yunnan, southwest China. We ran the Dobson algorithm under three surrogate scenarios at 75% and 100% conservation levels and identified four types of PCAs. Assessment of the protection efficiencies of the four types of PCAs showed that endangered plants had higher surrogacy values than endangered animals but that the two were not substitutable; coupled endangered plants and animals as surrogates yielded a higher surrogacy value than endangered plants or animals as surrogates; the plant-animal priority areas (PAPAs) was the optimal among the four types of PCAs for conserving both endangered plants and animals in Yunnan. PAPAs could well represent overall species diversity distribution patterns and overlap with critical biogeographical regions in Yunnan. Fourteen priority units in PAPAs should be urgently considered as optimizing Yunnan’s protected area system. The spatial pattern of PAPAs at the 100% conservation level could be conceptualized into three connected conservation belts, providing a valuable reference for optimizing the layout of the in situ protected area system in Yunnan.

SD simulation study on degraded farmland policy on farming-pastoral area under the constrains of water resources-Taking Tongliao City of Inner Mongolia as example

NASA Astrophysics Data System (ADS)

Xu, D. P.; Zhao, B.; Li, T. S.; Zhu, J. W.; Yu, M. M.

2017-08-01

Water resources are the primary factor in restricting the sustainable development of farming-pastoral regions. To support the sustainable development of water resources, whether or not the land uses patterns of farming-pastoral areas is a reasonably important issue. This paper takes Tongliao city as example for the purpose of sustainably developing the farming-pastoral area in the north. Several scientific preductions and evaluations were conducted to study the farming-pastoral landuse pattern, which is the key problem that effects sustainable development of farming-pastoral areas. The paper then proposes that 1:7 landuse pattern is suitable for the sustainable development of farming-pastotal area. Based on the analysis of the research findings on sustainable development of farming-pastoral area, the paper established a suitability evaluation indicators system of degraded farmland policies in Tongliao city, and used an Analytical Hierarchy Process (AHP) method to determine the weight to run system dynamic (SD) model. The simulation results were then obtained on social economic ecological development in Tongliao city under different degraded farmland policies, and used the comprehensive evaluation model to optimize the results. It is concluded that stabilizing the policy of degraded farmland policy is the preferential policy in Tongliao, which provides useful theoretical research for the sustainable development of farming-pastoral area.

Accelerating the degradation of green plant waste with chemical decomposition agents.

PubMed

Kejun, Sun; Juntao, Zhang; Ying, Chen; Zongwen, Liao; Lin, Ruan; Cong, Liu

2011-10-01

Degradation of green plant waste is often difficult, and excess maturity times are typically required. In this study, we used lignin, cellulose and hemicellulose assays; scanning electron microscopy; infrared spectrum analysis and X-ray diffraction analysis to investigate the effects of chemical decomposition agents on the lignocellulose content of green plant waste, its structure and major functional groups and the mechanism of accelerated degradation. Our results showed that adding chemical decomposition agents to Ficus microcarpa var. pusillifolia sawdust reduced the contents of lignin by 0.53%-11.48% and the contents of cellulose by 2.86%-7.71%, and increased the contents of hemicellulose by 2.92%-33.63% after 24 h. With increasing quantities of alkaline residue and sodium lignosulphonate, the lignin content decreased. Scanning electron microscopy showed that, after F. microcarpa var. pusillifolia sawdust was treated with chemical decomposition agents, lignocellulose tube wall thickness increased significantlyIncreases of 29.41%, 3.53% and 34.71% were observed after treatment with NaOH, alkaline residue and sodium lignosulphonate, respectively. Infrared spectroscopy showed that CO and aromatic skeleton stretching absorption peaks were weakened and the C-H vibrational absorption peak from out-of-plane in positions 2 and 6 (S units) (890-900 cm(-1)) was strengthened after F. microcarpa var. pusillifolia sawdust was treated with chemical decomposition agents, indicating a reduction in lignin content. Several absorption peaks [i.e., C-H deformations (asymmetry in methyl groups, -CH(3)- and -CH(2)-) (1450-1460 cm(-1)); Aliphatic C-H stretching in methyl and phenol OH (1370-1380 cm(-1)); CO stretching (cellulose and hemicellulose) (1040-1060 cm(-1))] that indicate the presence of a chemical bond between lignin and cellulose was reduced, indicating that the chemical bond between lignin and cellulose had been partially broken. X-ray diffraction analysis showed that Na

Long-term mesocosm experiments to investigate microbial degradation of fluorescent tracers

NASA Astrophysics Data System (ADS)

Fernández-Pascual, Elena; Zaman, Sameera; Lang, Friederike; Lange, Jens

2017-04-01

Uranine (UR) and sulforhodamine B (SRB) are two of the most commonly used fluorescent tracers in hydrology. Their suitability to be used as ideal tracers has been discussed since they might interact with the soil or become degraded. However, these properties have recently served to mimic processes of sorption and degradation of pollutants. The present study attempts to investigate to what extent UR and SRB could be used to imitate such processes in environments where saturation conditions are variable and the presence of plants might play an important role. For this purpose, both tracers were applied to 36 small mesocosms filled with a layer of 10 cm of gravel and 30 cm of sand in which 6 types of treatments, with 3 replicates each, were implemented based on the presence of two species of wetland plants (Typha latifolia and Phalaris arundinacea) and two types of hydrological conditions (saturated and unsaturated). The entire experiment lasted 10 months, during which two injections of equal concentration of tracers were performed. The first months served to ensure the adaptability of the plants and to achieve stationary conditions in the system. Water and sediment samples were collected weekly after the second injection while plants were measured at the end of the experiment distinguishing between roots and aerial parts. Mass balances of the tracers were combined with excitation emission matrix fluorescence spectroscopy (EEMS) to characterize dissolved organic matter in the water and soil. Degradation was quantified by subtracting the non-degraded tracer fraction (sorption and plant uptake) and the remaining non-degraded mass in the water from the tracer mass injected. Results revealed that most of the SRB accumulated in the sand in agreement with its sorption affinity, while UR was mainly found in the pore water. Both tracers showed more degradation in the treatments with plants than the controls. Overall, UR exhibited higher degradation than SRB. Differences

Integration of remote sensing and ground-based techniques for the study of land degradation phenomena in coastal areas.

NASA Astrophysics Data System (ADS)

Imbrenda, Vito; Coluzzi, Rosa; Calamita, Giuseppe; Luigia Giannossi, Maria; D'Emilio, Mariagrazia; Lanfredi, Maria; Makris, John; Palombo, Angelo; Pascucci, Simone; Santini, Federico; Margiotta, Salvatore; Emanuela Bonomo, Agnese; De Martino, Gregory; Perrone, Angela; Rizzo, Enzo; Pignatti, Stefano; Summa, Vito; Simoniello, Tiziana

2015-04-01

Land degradation processes, such as salinization and waterlogging, are increasingly affecting extensive areas devoted to agriculture threatening the sustainability of farming practices. Soil salinization typically appears as an excess accumulation of salt generally pronounced at the soil surface. Commonly, soil salinity is defined and measured by means of laboratory measurements of the electrical conductivity of liquid extracted from saturated soil-paste or different soil-water suspensions. Lab measurements are generally time consuming, costly, destructive, untimely for practical situations where the determination of the causes and/or the assessment of management practices are of interest. Recently, emerging survey techniques proved to be powerful tools to support soil salinity appraisal reducing costs and increasing the amount of spatial information. In the frame of PRO-LAND project (PO-FESR Basilicata 2007-2013) the research activities have been focused on the study of a complex salinization phenomenon occurring in a coastal environment of the Basilicata region (Southern Italy) as a result of natural and anthropic disturbances. The study area is located in the southernmost part of the Bradanic Trough along the sandy Ionian coastal plain. The hydrogeological conditions affect shallowness of the aquifer (45-50 cm below the ground) allowing the occurrence of seawater intrusion. Moreover, during last century, human activities, i.e. built-up of dams, the emergence of farms and industries, played a relevant role in the alteration of soil and groundwater quality of the area. In this work, both ground-based and remote sensing data were used. First, a geophysical mapping of electrical conductivity was carried out using a multi-frequency portable electro-magnetic induction (EMI) sensor. Based on the geophysical mapping and on optimization sampling approach, a number of locations were identified to collect soil samples for the geomineralogical characterization. Airborne

Recovery of Areas Degraded by Mining Within the Amazon Forest: Interaction of the Physical Condition of Soil and Biological Activity

NASA Astrophysics Data System (ADS)

Ribeiro, A. I.; Mello, G. F.; Longo, R. M.; Fengler, F. H.; Peche Filho, A., Sr.

2017-12-01

One of the greatest natural riches of Brazil is the Amazon rainforest. The Amazon region is known for its abundance of mineral resources, and may include topaz, oil, and especially cassiterite. In this scope, the mining sector in Brazil has great strategic importance because it accounts for approximately 30% of the country's exports with a mineral production of 40 billion dollars (Brazilian Mining Institute, 2015). In this scenario, as a consequence of mining, the Amazonian ecosystem has been undergoing a constant process of degradation. An important artifice in the exploitation of mineral resources is the rehabilitation and/or recovery of degraded areas. This recovery requires the establishment of degradation indicators and also the quality of the soil associated with its biota, since the Amazonian environment is dynamic, heterogeneous and complex in its physical, chemical and biological characteristics. In this way, this work presupposes that it is possible to characterize the different stages of recovery of tillage floor areas in deactivated cassiterite mines, within the Amazonian forest, in order to evaluate the interactions between the level of biological activity (Serrapilheira Height, Coefficient Metabolic, Basal Breath) and physical soil characteristics (aggregate DMG, Porosity, Total Soil Density, Moisture Content), through canonical correlation analysis. The results present correlations between the groups of indicators. Thus, from the use of the groups defined by canonical correlations, it was possible to identify the response of the set of physical and biological variables to the areas at different stages of recovery.

Plant diversity at Box-Death Hollow Wilderness Area, Garfield County, Utah

Treesearch

Wendy Rosler; Janet G. Cooper; Renee Van Buren; Kimball T. Harper

2001-01-01

"The Box" is a canyon located in the western portion of Box-Death Hollow Wilderness Area, Garfield County, southern Utah. The objectives of this study included: (1) collect, identify and make a checklist of the species of vascular plants found in "The Box," (2) search for threatened and endangered species within the area, (3) provide an opportunity...

An overview of degradable polymers

USDA-ARS?s Scientific Manuscript database

Many degradable polymers are being investigated for research purpose or for possible commercial use. This overview provides a listing of the more important degradable polymers and their mechanisms of action. Some application areas, particularly in packaging, housewares, personal care, biomaterials, ...

An overview of degradable polymers

USDA-ARS?s Scientific Manuscript database

Many degradable polymers are being investigated for research purpose or for possible commercial use. This overview provides a listing of the more important degradable polymers and their mechanisms of action. Some application areas, particularly in packaging, housewares, personal care, biomaterials...

Characterization of Radiation Fields in Biological Shields of Nuclear Power Plants for Assessing Concrete Degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Remec, Igor; Rosseel, Thomas M; Field, Kevin G

Life extensions of nuclear power plants to 60 and potentially 80 years of operation have renewed interest in long-term material degradation. One material being considered is concrete with a particular focus on radiation-induced effects. Based on the projected neutron fluence (E > 0.1 MeV) values in the concrete biological shields of the US PWR fleet and the available data on radiation effects on concrete, some decrease in mechanical properties of concrete cannot be ruled out during extended operation beyond 60 years. An expansion of the irradiated concrete database and a reliable determination of relevant neutron fluence energy cutoff value aremore » necessary to assure reliable risk assessment for NPPs extended operation.« less

[Native plant resources to optimize the performances of forest rehabilitation in Mediterranean and tropical environment: some examples of nursing plant species that improve the soil mycorrhizal potential].

PubMed

Duponnois, Robin; Ramanankierana, Heriniaina; Hafidi, Mohamed; Baohanta, Rondro; Baudoin, Ezékiel; Thioulouse, Jean; Sanguin, Hervé; Bâ, Amadou; Galiana, Antoine; Bally, René; Lebrun, Michel; Prin, Yves

2013-01-01

The overexploitation of natural resources, resulting in an increased need for arable lands by local populations, causes a serious dysfunction in the soil's biological functioning (mineral deficiency, salt stress, etc.). This dysfunction, worsened by the climatic conditions (drought), requires the implementation of ecological engineering strategies allowing the rehabilitation of degraded areas through the restoration of essential ecological services. The first symptoms of weathering processes of soil quality in tropical and Mediterranean environments result in an alteration of the plant cover structure with, in particular, the pauperization of plant species diversity and abundance. This degradation is accompanied by a weakening of soils and an increase of the impact of erosion on the surface layer resulting in reduced fertility of soils in terms of their physicochemical characteristics as well as their biological ones (e.g., soil microbes). Among the microbial components particularly sensitive to erosion, symbiotic microorganisms (rhizobia, Frankia, mycorrhizal fungi) are known to be key components in the main terrestrial biogeochemical cycles (C, N and P). Many studies have shown the importance of the management of these symbiotic microorganisms in rehabilitation and revegetation strategies of degraded environments, but also in improving the productivity of agrosystems. In particular, the selection of symbionts and their inoculation into the soil were strongly encouraged in recent decades. These inoculants were selected not only for their impact on the plant, but also for their ability to persist in the soil at the expense of the residual native microflora. The performance of this technique was thus evaluated on the plant cover, but its impact on soil microbial characteristics was totally ignored. The role of microbial diversity on productivity and stability (resistance, resilience, etc.) of eco- and agrosystems has been identified relatively recently and has led

Plant management in natural areas: balancing chemical, mechanical, and cultural control methods

Treesearch

Steven Manning; James Miller

2011-01-01

After determining the best course of action for control of an invasive plant population, it is important to understand the variety of methods available to the integrated pest management professional. A variety of methods are now widely used in managing invasive plants in natural areas, including chemical, mechanical, and cultural control methods. Once the preferred...

Stable carbon isotope as a signal index for monitoring grassland degradation

NASA Astrophysics Data System (ADS)

Yao, Hongyun; Wilkes, Andreas; Zhu, Guodong; Zhang, Hongdan; Liu, Xiaojuan; Dan Ding; Zhai, Xiajie; Tang, Shiming; Chen, Qing; Zhang, Yujuan; Huang, Ding; Wang, Chengjie

2016-08-01

Grassland degradation due to overgrazing is common in many areas of the world. This study analyzed the potential of the stable carbon isotope (δ13C) value as a structural microcosmic index to monitor processes of grassland degradation. The δ13C values of plant leaves, roots and soils in non-grazed (NG) and over-grazed (OG) grassland were measured from samples collected from the seven types of grassland in China. We found that the leaf δ13C values of palatable species (δ13Cleaf) and root δ13C values (δ13Croot) in OG grasslands were reduced compared with those from NG grasslands. Furthermore, the δ13Cleaf and δ13Csoil were positive correlation with elevation and latitude, δ13Croot was negative correlation with them at high altitude (3000~5000m), and δ13Croot and δ13Csoil were negative correlation with them at low altitude (0~2000m), respectively. Consequently, tracing of the δ13C variations in grassland ecosystem can provide a powerful tool to evaluate the degree of grassland degradation.

Stable carbon isotope as a signal index for monitoring grassland degradation.

PubMed

Yao, Hongyun; Wilkes, Andreas; Zhu, Guodong; Zhang, Hongdan; Liu, Xiaojuan; Dan Ding; Zhai, Xiajie; Tang, Shiming; Chen, Qing; Zhang, Yujuan; Huang, Ding; Wang, Chengjie

2016-08-16

Grassland degradation due to overgrazing is common in many areas of the world. This study analyzed the potential of the stable carbon isotope (δ(13)C) value as a structural microcosmic index to monitor processes of grassland degradation. The δ(13)C values of plant leaves, roots and soils in non-grazed (NG) and over-grazed (OG) grassland were measured from samples collected from the seven types of grassland in China. We found that the leaf δ(13)C values of palatable species (δ(13)Cleaf) and root δ(13)C values (δ(13)Croot) in OG grasslands were reduced compared with those from NG grasslands. Furthermore, the δ(13)Cleaf and δ(13)Csoil were positive correlation with elevation and latitude, δ(13)Croot was negative correlation with them at high altitude (3000~5000m), and δ(13)Croot and δ(13)Csoil were negative correlation with them at low altitude (0~2000m), respectively. Consequently, tracing of the δ(13)C variations in grassland ecosystem can provide a powerful tool to evaluate the degree of grassland degradation.

Stable carbon isotope as a signal index for monitoring grassland degradation

PubMed Central

Yao, Hongyun; Wilkes, Andreas; Zhu, Guodong; Zhang, Hongdan; Liu, Xiaojuan; Dan Ding; Zhai, Xiajie; Tang, Shiming; Chen, Qing; Zhang, Yujuan; Huang, Ding; Wang, Chengjie

2016-01-01

Grassland degradation due to overgrazing is common in many areas of the world. This study analyzed the potential of the stable carbon isotope (δ13C) value as a structural microcosmic index to monitor processes of grassland degradation. The δ13C values of plant leaves, roots and soils in non-grazed (NG) and over-grazed (OG) grassland were measured from samples collected from the seven types of grassland in China. We found that the leaf δ13C values of palatable species (δ13Cleaf) and root δ13C values (δ13Croot) in OG grasslands were reduced compared with those from NG grasslands. Furthermore, the δ13Cleaf and δ13Csoil were positive correlation with elevation and latitude, δ13Croot was negative correlation with them at high altitude (3000~5000m), and δ13Croot and δ13Csoil were negative correlation with them at low altitude (0~2000m), respectively. Consequently, tracing of the δ13C variations in grassland ecosystem can provide a powerful tool to evaluate the degree of grassland degradation. PMID:27527910

Phragmites australis root secreted phytotoxin undergoes photo-degradation to execute severe phytotoxicity.

PubMed

Rudrappa, Thimmaraju; Choi, Yong Seok; Levia, Delphis F; Legates, David R; Lee, Kelvin H; Bais, Harsh P

2009-06-01

Our study organism, Phragmites australis (common reed), is a unique invader in that both native and introduced lineages are found coexisting in North America. This allows one to make direct assessments of physiological differences between these different subspecies and examine how this relates to invasiveness. Recent efforts to understand plant invasive behavior show that some invasive plants secrete a phytotoxin to ward-off encroachment by neighboring plants (allelopathy) and thus provide the invaders with a competitive edge in a given habitat. Here we show that a varying climatic factor like ultraviolet (UV) light leads to photo-degradation of secreted phytotoxin (gallic acid) in P. australis rhizosphere inducing higher mortality of susceptible seedlings. The photo-degraded product of gallic acid (hereafter GA), identified as mesoxalic acid (hereafter MOA), triggered a similar cell death cascade in susceptible seedlings as observed previously with GA. Further, we detected the biological concentrations of MOA in the natural stands of exotic and native P. australis. Our studies also show that the UV degradation of GA is facilitated at an alkaline pH, suggesting that the natural habitat of P. australis may facilitate the photo-degradation of GA. The study highlights the persistence of the photo-degraded phytotoxin in the P. australis's rhizosphere and its inhibitory effects against the native plants.

Heavy Metal Bioaccumulation Capability of Woody Plants in Mine wasteland of Karst Areas

NASA Astrophysics Data System (ADS)

Xiuru, Wang; Zhongliang, Huang; Xuan, Zhang; Zijian, Wu

2017-04-01

The bioaccumulation capability and transfer characteristics of Pb, Zn, Cu and Cd in soil and 6 different woody plants collected from a typical lead-zinc mine wasteland of Karst area, Hunan province were investigated, including Cunninghamia lanceolata(Lamb.) Hook., Swida wilsoniana (Wanger.), Koelreuteria paniculata, Paulownia., Cinnamomum camphora (L.) Presl., and Sapium sebiferum (L.) Roxb. The results showed that the 6 plants could adapt to the heavy metal polluted environment, and there was a positive correlation between the heavy metal content in plants and soil.Swida wilsoniana (Wanger.) and Sapium sebiferum (L.) Roxb. had the largest Pb bioaccumulation factor of 0.03; Paulownia. had the highest Zn bioaccumulation factor of 0.37; the largest Pb transfer factor of 1.31 were found in Koelreuteria paniculata; and Zn transfer factor of Paulownia. reached 1.45. These 4 woody plants are suitable for phytoremediation of mine wasteland of Karst areas.

Pregnancy detecting plants used in Remo and Ijebu areas of Ogun State, Nigeria.

PubMed

Fred-Jaiyesimi, Adediwura; Taiwo, Jolaade

2017-01-01

Plants and plants extracts are employed in cultures for religious purposes, as beauty therapies, in the detection and management/treatment of diseases. In this study, an ethnobotanical studies of plants used in detecting pregnancy in Ijebu and Remo areas of Ogun State were carried out using semi-structured to obtain demographic data, local names of plants, the morphological parts used. Furthermore, a phytochemical analysis of two of the identified plants was performed. Topical and urine tests of plants in detecting pregnancy were designed to mimic procedures used in traditional medicine for detecting pregnancy. Five plant species were identified belonging to the families Araceae, Asteraceae, Convolvulaceae, Nyctaginaceae, and Rubiaceae in the survey. The identified plants had the use value (UV) of 0.25 ( Culcasia scandens ), 0.17 ( Ipomoea mauritiana ), Boerhavia diffusa while Launea taraxacifolia and Chassalia kolly had the UV of 0.08, respectively. B. diffusa L, C. kolly (Schumach) Hepper tested positive for the presence of flavonoids, alkaloids, and tannins. The onset and duration of symptoms of both B. diffusa and C. kolly leaves at 2000 and 1000 mg were dose-dependent. The hexane, ethyl acetate, and ethanol extracts of B. diffusa and C. kolly exhibited pruritus and restlessness in the in vivo model while the urine of pregnant women caused black spots on the leaves of L. taraxacifolia (Willd) Amin Ex. C. Jeffrey. This study reports a rare knowledge of using plants in detecting pregnancy in the Remo and Ijebu areas of Ogun State, Nigeria.

Improving management of nonnative invasive plants in wilderness and other natural areas

Treesearch

John M. Randall

2000-01-01

Nonnative invasive plants invade wilderness and other natural areas throughout North America and invasive organisms as a group are now considered the second worst threat to biodiversity, behind only habitat loss and fragmentation. In the past 10-20 years there have been upsurges in interest in the ecology of plant invasions among researchers and in concern about how to...

An ethnobotanical study of medicinal plants used by tribal and native people of Madhupur forest area, Bangladesh.

PubMed

Islam, Md Khirul; Saha, Sanjib; Mahmud, Imran; Mohamad, Khalit; Awang, Khalijah; Jamal Uddin, Shaikh; Rahman, Md Mustafizur; Shilpi, Jamil A

2014-02-03

Madhupur forest area, Tangail is one of early human settlements in Bangladesh. Having abode in the vicinity of the forest, a strong ethnobotanical practice has prevailed in this area since ancient time. Due to the rapid deforestation during the last few decades, many plants have already disappeared or are facing extinction. Thus we attempted to document the medicinal plant use of Madhupur forest area with a view to preserve the ethnobotanical knowledge and in order to protect the biodiversity of this area. The fieldwork was conducted during a period of 1 year. Data was collected by interview, questionnaire, and group discussion with randomly selected informants including indigenous, tribal people, and Traditional Health Practitioners (THPs) living in the study area. Recorded plants are listed along with their indication, part used, form of preparation and use value (UV). Results were also analysed to determine informant consensus factor (ICF) and fidelity level (FL) of the plants on the basis of their use under various ailment categories. The present study has documented 78 medicinal plant species from 45 families used for the treatment of at least 77 different major and minor ailments and conditions. Medicinal plant species were categorised as tree, shrub, tuber, herb, and climber. Leaves were found to be the most frequently used plant part while decoction is the major form of preparation. In most cases preparations are either administered orally or applied topically. The present study revealed that some of the well-known medicinal plants are used extensively demonstrating an effective ethnobotanical practice in the study area. Plants with high ICF and FL values can be subjected to bioassay guided investigation while plants which scored low UVs require bioactivity screening to justify their use for the reported ailment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

An ethnobotanical study of medicinal plants used by the Zay people in Ethiopia.

PubMed

Giday, Mirutse; Asfaw, Zemede; Elmqvist, Thomas; Woldu, Zerihun

2003-03-01

An ethnobotanical survey was carried out to collect information on the use of medicinal plants by the Zay people who live on islands as well as shore areas of Lake Ziway in the Ethiopian Rift Valley. A total of 33 medicinal plants were reported as being used locally for the treatment and/or control of human and livestock ailments. Results of the survey showed that leaf materials form the major component of plant parts harvested. The majority of the remedies are prepared in the form of juice from freshly collected plant parts. Most of the remedies are prepared from a single species, and are mainly taken orally. Most of the medicinal plants are collected from the wild. Of the total claimed medicinal plants, 10 were reported scarce locally. Environmental degradation and intense deforestation have been reported as the main causes for the depletion of medicinal plants in the area. As the Zay people are still partly dependent on medicinal plants, loss of these plants will, to a certain extent, hamper the existing health care system in the area. Measures for conservation of medicinal plants of the Zay people are urgently needed.

Dissipation and enantioselective degradation of plant growth retardants paclobutrazol and uniconazole in open field, greenhouse, and laboratory soils.

PubMed

Wu, Chengwang; Sun, Jianqiang; Zhang, Anping; Liu, Weiping

2013-01-15

Greenhouses are increasingly important in human food supply. Pesticides used in greenhouses play important roles in horticulture; however, little is known about their behavior in greenhouse environments. This work investigates the dissipation and enantioselctive degradation of plant growth retardants including paclobutrazol and uniconazole in soils under three conditions (i.e., open field, greenhouse, and laboratory). The dissipation and enantioselective degradation of paclobutrazol and uniconazole in greenhouse were different from those in open field; they were more persistent in greenhouse than in open field soil. Leaching produced by rainfall is responsible for the difference in dissipation. Thus, local environmental impacts may occur more easily inside greenhouses, while groundwater may be more contaminated in open field. Spike concentrations of 5, 10, and 20 times the concentrations of native residues were tested for the enantioselective dissipation of the two pesticides; the most potent enantioselective degradation of paclobutrazol and uniconazole occurred at the 10 times that of the native residues in the greenhouse environments and at 20 times native residues in open field environments. The higher soil activity in greenhouses than in open fields was thought to be responsible for such a difference. The environmental risk and regulation of paclobutrazol and uniconazole should be considered at the enantiomeric level.

The Soil Biota Composition along a Progressive Succession of Secondary Vegetation in a Karst Area

PubMed Central

He, Xunyang; Liu, Lu; Wang, Kelin

2014-01-01

Karst ecosystems are fragile and are in many regions degraded by anthropogenic activities. Current management of degraded karst areas focuses on aboveground vegetation succession or recovery and aims at establishing a forest ecosystem. Whether progressive succession of vegetation in karst areas is accompanied by establishment of soil biota is poorly understood. In the present study, soil microbial and nematode communities, as well as soil physico-chemical properties were studied along a progressive succession of secondary vegetation (from grassland to shrubland to forest) in a karst area in southwest China. Microbial biomass, nematode density, ratio of fungal to bacterial biomass, nematode structure index, and nematode enrichment index decreased with the secondary succession in the plant community. Overall, the results indicated a pattern of declines in soil biota abundance and food web complexity that was associated with a decrease in soil pH and a decrease in soil organic carbon content with the progressive secondary succession of the plant community. Our findings suggest that soil biota amendment is necessary during karst ecosystem restoration and establishment and management of grasslands may be feasible in karst areas. PMID:25379741

Enrichment and Broad Representation of Plant Biomass-Degrading Enzymes in the Specialized Hyphal Swellings of Leucoagaricus gongylophorus, the Fungal Symbiont of Leaf-Cutter Ants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aylward, Frank O.; Khadempour, Lily; Tremmel, Daniel

Leaf-cutter ants are prolific and conspicuous Neotropical herbivores that derive energy from specialized fungus gardens they cultivate using foliar biomass. The basidiomycetous cultivar of the ants, Leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. Gongylidia also contain lignocellulases that become concentrated in ant digestive tracts and are deposited within fecal droplets onto fresh foliar material as it is foraged by the ants. Although the enzymes concentrated by L. gongylophorus within gongylidia are thought to be critical to the initial degradation of plant biomass, only a few enzymes present in thesemore » hyphal swellings have been identified. Here we use proteomic methods to identify proteins present in the gongylidia of three Atta cephalotes colonies. Our results demonstrate that a diverse but consistent set of enzymes is present in gongylidia, including numerous lignocellulases likely involved in the degradation of polysaccharides, plant toxins, and proteins. Overall, gongylidia contained over three-quarters of all lignocellulases identified in the L. gongylophorus genome, demonstrating that the majority of the enzymes produced by this fungus for biomass breakdown are ingested by the ants. We also identify a set of 23 lignocellulases enriched in gongylidia compared to whole fungus garden samples, suggesting that certain enzymes may be particularly important in the initial degradation of foliar material. Our work sheds light on the complex interplay between leaf-cutter ants and their fungal symbiont that allows for the host insects to occupy an herbivorous niche by indirectly deriving energy from plant biomass.« less

Bacterial community analysis of an industrial wastewater treatment plant in Colombia with screening for lipid-degrading microorganisms.

PubMed

Silva-Bedoya, Lina Marcela; Sánchez-Pinzón, María Solange; Cadavid-Restrepo, Gloria Ester; Moreno-Herrera, Claudia Ximena

2016-11-01

The operation of wastewater treatment technologies depends on a combination of physical, chemical and biological factors. Microorganisms present in wastewater treatment plants play essential roles in the degradation and removal of organic waste and xenobiotic pollutants. Several microorganisms have been used in complementary treatments to process effluents rich in fats and oils. Microbial lipases have received significant industrial attention because of their stability, broad substrate specificity, high yields, and regular supply, as well as the fact that the microorganisms producing them grow rapidly on inexpensive media. In Colombia, bacterial community studies have focused on populations of cultivable nitrifying, heterotrophic and nitrogen-fixing bacteria present in constructed wetlands. In this study, culture-dependent methods, culture-independent methods (TTGE, RISA) and enzymatic methods were used to estimate bacterial diversity, to monitor temporal and spatial changes in bacterial communities, and to screen microorganisms that presented lipolytic activity. The dominant microorganisms in the Wastewater Treatment Plant (WWTP) examined in this study belonged to the phyla Firmicutes, Proteobacteria and Bacteroidetes. The enzymatic studies performed indicated that five bacterial isolates and three fungal isolates possessed the ability to degrade lipids; additionally, the Serratia, Kosakonia and Mucor genera presented lipase-mediated transesterification activity. The implications of these findings in regard to possible applications are discussed later in this paper. Our results indicate that there is a wide diversity of aerobic Gram-negative bacteria inhabiting the different sections of the WWTP, which could indicate its ecological condition, functioning and general efficiency. Copyright © 2016 Elsevier GmbH. All rights reserved.

Household dyeing plants and traditional uses in some areas of Italy

PubMed Central

Guarrera, Paolo Maria

2006-01-01

Background This paper reports the results of investigations carried out from 1977 to today in some areas of Italy (Latium, Marche, Abruzzo and to a limited extent in Sardinia) concerning traditional uses of dyeing plants in the household. Results Twenty-nine plants are described, distributed in 23 families, and for each species the vernacular name, the way it is used and the locations of traditional use are given. Other plants used in the past in the above-mentioned regions are recalled. Conclusion Among the new findings – not mentioned in previous literature, see references – is Muscari neglectum (purplish). Nowadays atavistic dye uses still persist only in Nule (Sardinia). PMID:16457717

Soil quality changes in land degradation as indicated by soil chemical, biochemical and microbiological properties in a karst area of southwest Guizhou, China

NASA Astrophysics Data System (ADS)

Zhang, Pingjiu; Li, Lianqing; Pan, Genxing; Ren, Jingchen

2006-12-01

Not only the nutritional status and biological activity but also the soil ecological functioning or soil health has been impacted profoundly by land degradation in the karst area of southwest China where the karst ecosystems are generally considered as extremely vulnerable to land degradation under intensified land-use changes. The objectives of this study are to elucidate the changes in overall soil quality by a holistic approach of soil nutritional, biological activity, and soil health indicators in the karst area as impacted by intense cultivation and vegetation degradation. Topsoil samples were collected on selected eco-tesserae in a sequence of land degradation in a karst area of southwest Guizhou in 2004. The soil nutrient pools of organic carbon (Corg), extractable extracellular carbon (Cext), total soil nitrogen (Nt), alkali-hydrolyzable nitrogen (Nah), total phosphorus (Pt), available phosphorus (Pa) were analyzed by wet soil chemistry. The soil biological properties were studied by means of measurements of microbial biomass carbon (both by fumigation-extraction, FE-Cmic, and by calculation from substrate-incubation respiration, SIR-Cmic) of respiration [respiration without addition of substrates, basal respiration (BR), and potential respiration (PR) with substrate-incubation] and of soil enzyme activities (invertase, urease, and alkaline phosphatase). Soil health status was assessed by simple indices of Cmic/Corg and BR/Cmic in conjunction with bacterial community structures determined by polymerase chain reaction and denaturing gradient gel electrophoresis. While the nutritional pool parameters, such as Corg and Cext, described basically the changes in soil life-supporting capacity with cultivation interference and vegetation declined, those parameters of biological activity such as FE-Cmic, SIR, and SIR-Cmic as well as bacterial community structures measured by molecular method evidenced well the changes in soil functioning for ecosystem health with

Working session 1: Tubing degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kharshafdjian, G.; Turluer, G.

1997-02-01

A general introductory overview of the purpose of the group and the general subject area of SG tubing degradation was given by the facilitator. The purpose of the session was described as to {open_quotes}develop conclusions and proposals on regulatory and technical needs required to deal with the issues of SG tubing degradation.{close_quotes} Types, locations and characteristics of tubing degradation in steam generators were briefly reviewed. The well-known synergistic effects of materials, environment, and stress and strain/strain rate, subsequently referred to by the acronym {open_quotes}MESS{close_quotes} by some of the group members, were noted. The element of time (i.e., evolution of thesemore » variables with time) was emphasized. It was also suggested that the group might want to consider the related topics of inspection capabilities, operational variables, degradation remedies, and validity of test data, and some background information in these areas was provided. The presentation given by Peter Millet during the Plenary Session was reviewed; Specifically, the chemical aspects and the degradation from the secondary side of the steam generator were noted. The main issues discussed during the October 1995 EPRI meeting on secondary side corrosion were reported, and a listing of the potential SG tube degradations was provided and discussed.« less

Land Degradation is The Instinctive Source of Poverty in Rural Areas of Pakistan

NASA Astrophysics Data System (ADS)

Qiu, L. L.; Koondhar, M. A.; Liu, Y. Y.; Zeng, W. Z.

2017-10-01

This review paper focused on the correlation between land degradation and poverty. Pakistan is an agricultural country and agriculture is the backbone of Pakistan`s economy. For the rapid growth of population food security should be under guarantee as well as the food production. In that farmers overused agrarian inputs, such as fertilizer, pesticide and water, environment and farmers were affected from the perspective of contamination and disease increase respectively. Due to over-exploitation of fertilizer and irrigation, ground water was contaminated, soil fertility weakening,salinity increasing and waterlogged. Consequently, soil was hard to be cultivated. In Pakistan 70% of people live in rural areas who are directly or indirectly involved in agriculture. As a result of land degradation farmers can not gain much benefit from agricultural activities and they are also unable to feed their children. Many of them became criminals, therefore, poverty deepened day after day. In order to alleviate poverty, Pakistan government should subsidize farmers on environmentally friendly inputs and; government should also open agricultural training schools to engage farmers in modern methods of cultivation, and provide modern technologies with subsidy rate. When the farmers are aware of how to increase the fertility of soil by employing modern methods, they can gain higher production, and obvious higher production is critical for living a better life and reducing poverty.

[Water utilization characteristics of the degraded poplar shelterbelts in Zhangbei, Hebei, China.

PubMed

Zhang, Huan; Cao, Jun; Wang, Hua Bing; Song, Bo; Jia, Guo Dong; Liu, Zi Qiang; Yu, Xin Xiao; Zeng, Jia

2018-05-01

In Zhangbei County, Hebei Province, poplar-dominated shelterbelts are degraded to different extents. Water availability is the main limiting factor for plant survival in arid areas. The purpose of this study was to reveal the relationship between water availability and poplar degradation. Based on the hydrogen and oxygen stable isotope techniques, we explored the water sources of Populus simonii under different degradation degrees by comparing the isotopic values of P. simonii xylem water with that in potential water source, and calculated the utilization ratio of each water source. The results showed that the water sources of poplar trees varied with degradation degree. The water sources of P. simonii gradually transferred from the deep layer to the surface layer with the increases of degradation. P. simonii with no degradation mainly absorbed soil water in the range of 320-400 cm, with the utilization rate being 25.1%. P. simonii with slight degradation mainly used soil water at depth of 120-180, 180-240 and 240-320 cm. The total utilization rate of three layers was close to 50.0%, with less utilization of water from other layers. The moderately degraded P. simonii mainly used soil water at depth of 20-40, 40-60 and 60-80 cm. The utilization rate of each layer was 17.5%-20.9%, and the contribution rate of soil water under 120 cm was less than 10.0%. The severely degraded P. simonii mainly used water from surface soil layer (0-20 cm), with the utilization rate being 30.4%, which was significantly higher than that of other water sources. The water sources of poplar shelter forests were gradually shallower during the process of degradation. However, the low soil water content in the shallow layer could not meet the normal water demand of poplar, which would accelerate the degradation and even decline of poplar.

The potential impact of invasive woody oil plants on protected areas in China under future climate conditions.

PubMed

Dai, Guanghui; Yang, Jun; Lu, Siran; Huang, Conghong; Jin, Jing; Jiang, Peng; Yan, Pengbo

2018-01-18

Biodiesel produced from woody oil plants is considered a green substitute for fossil fuels. However, a potential negative impact of growing woody oil plants on a large scale is the introduction of highly invasive species into susceptible regions. In this study, we examined the potential invasion risk of woody oil plants in China's protected areas under future climate conditions. We simulated the current and future potential distributions of three invasive woody oil plants, Jatropha curcas, Ricinus communis, and Aleurites moluccana, under two climate change scenarios (RCP2.6 and RCP8.5) up to 2050 using species distribution models. Protected areas in China that will become susceptible to these species were then identified using a spatial overlay analysis. Our results showed that by 2050, 26 and 41 protected areas would be threatened by these invasive woody oil plants under scenarios RCP2.6 and RCP8.5, respectively. A total of 10 unique forest ecosystems and 17 rare plant species could be potentially affected. We recommend that the invasive potential of woody oil plants be fully accounted for when developing forest-based biodiesel, especially around protected areas.

Fermentation performance of lactic acid bacteria in different lupin substrates-influence and degradation ability of antinutritives and secondary plant metabolites.

PubMed

Fritsch, C; Vogel, R F; Toelstede, S

2015-10-01

The main objectives were to determine the influence of secondary plant metabolites and antinutritives in lupin seeds on the fermentation performance of lactic acid bacteria and to study their ability to degrade these substances. The suitability of lupin raw materials as fermentation substrates was examined. To evaluate the fermentation performance, microbial growth, metabolite formation and substrate uptake in three different lupin substrates was monitored. On the one hand, a lupin protein isolate, which contained only trace amounts of phytochemicals was used in the study. On the other hand, the flour of Lupinus angustifolius cv. Boregine and the flour of the alkaloid rich lupin Lupinus angustifolius cv. Azuro were inoculated with Bifidobacterium animalis subsp. lactis, Pediococcus pentosaceus, Lactobacillus plantarum and Lactococcus lactis subsp. lactis. The micro-organisms showed no significant differences in the fermentation performance on the different lupin flours. Similarly, the growth of most strains on lupin protein isolate was comparable to that on the lupin flours. The fermentation with Bifidobacterium animalis subsp. lactis led to a significant decrease in flatulence causing oligosaccharides. During fermentation with Lactobacillus plantarum the phytic acid content was partially degraded. Neither the secondary plant metabolites nor the antinutritives of lupin flour inhibited the growth or metabolic activity of the tested micro-organisms. Therefore, lupin flour is suitable for lactic fermentation. Some strains showed the ability to degrade oligosaccharides or phytic acid. This work contributes to the fundamental knowledge of the metabolism of lactic acid bacteria during fermentation of lupin substrates. Fermentation of lupin raw materials could be used to improve the nutritional value of the substrates due to the reduction of antinutritives. © 2015 The Society for Applied Microbiology.

Phytoremediation: plant-endophyte partnerships take the challenge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weyens, N.; van der Lelie, D.; Taghavi, S.

A promising field to exploit plant-endophyte partnerships is the remediation of contaminated soils and (ground) water. Many plant growth promoting endophytes can assist their host plant to overcome contaminant-induced stress responses, thus providing improved plant growth. During phytoremediation of organic contaminants, plants can further benefit from endophytes possessing appropriate degradation pathways and metabolic capabilities, leading to more efficient contaminant degradation and reduction of both phytotoxicity and evapotranspiration of volatile contaminants. For phytoremediation of toxic metals, endophytes possessing a metal-resistance/sequestration system can lower metal phytotoxicity and affect metal translocation to the above-ground plant parts. Furthermore, endophytes that can degrade organic contaminantsmore » and deal with or, even better, improve extraction of the metals offer promising ways to improve phytoremediation of mixed pollution.« less

Transcript Lifetime Is Balanced between Stabilizing Stem-Loop Structures and Degradation-Promoting Polyadenylation in Plant Mitochondria

PubMed Central

Kuhn, Josef; Tengler, Ulrike; Binder, Stefan

2001-01-01

To determine the influence of posttranscriptional modifications on 3′ end processing and RNA stability in plant mitochondria, pea atp9 and Oenothera atp1 transcripts were investigated for the presence and function of 3′ nonencoded nucleotides. A 3′ rapid amplification of cDNA ends approach initiated at oligo(dT)-adapter primers finds the expected poly(A) tails predominantly attached within the second stem or downstream of the double stem-loop structures at sites of previously mapped 3′ ends. Functional studies in a pea mitochondrial in vitro processing system reveal a rapid removal of the poly(A) tails up to termini at the stem-loop structure but little if any influence on further degradation of the RNA. In contrast 3′ poly(A) tracts at RNAs without such stem-loop structures significantly promote total degradation in vitro. To determine the in vivo identity of 3′ nonencoded nucleotides more accurately, pea atp9 transcripts were analyzed by a direct anchor primer ligation-reverse transcriptase PCR approach. This analysis identified maximally 3-nucleotide-long nonencoded extensions most frequently of adenosines combined with cytidines. Processing assays with substrates containing homopolymer stretches of different lengths showed that 10 or more adenosines accelerate RNA processivity, while 3 adenosines have no impact on RNA life span. Thus polyadenylation can generally stimulate the decay of RNAs, but processivity of degradation is almost annihilated by the stabilizing effect of the stem-loop structures. These antagonistic actions thus result in the efficient formation of 3′ processed and stable transcripts. PMID:11154261

A review on plant importance, biotechnological aspects, and cultivation challenges of jojoba plant.

PubMed

Al-Obaidi, Jameel R; Halabi, Mohammed Farouq; AlKhalifah, Nasser S; Asanar, Shanavaskhan; Al-Soqeer, Abdulrahman A; Attia, M F

2017-08-24

Jojoba is considered a promising oil crop and is cultivated for diverse purposes in many countries. The jojoba seed produces unique high-quality oil with a wide range of applications such as medical and industrial-related products. The plant also has potential value in combatting desertification and land degradation in dry and semi-dry areas. Although the plant is known for its high-temperature and high-salinity tolerance growth ability, issues such as its male-biased ratio, relatively late flowering and seed production time hamper the cultivation of this plant. The development of efficient biotechnological platforms for better cultivation and an improved production cycle is a necessity for farmers cultivating the plant. In the last 20 years, many efforts have been made for in vitro cultivation of jojoba by applying different molecular biology techniques. However, there is a lot of work to be done in order to reach satisfactory results that help to overcome cultivation problems. This review presents a historical overview, the medical and industrial importance of the jojoba plant, agronomy aspects and nutrient requirements for the plant's cultivation, and the role of recent biotechnology and molecular biology findings in jojoba research.

Pasture degradation in Tibet: Drivers, mechanisms and consequences for C stocks and ecosystem stability

NASA Astrophysics Data System (ADS)

Kuzyakov, Yakov; Schleuss, Per-Marten; Guggenberger, Georg; Miehe, Georg; Coners, Heinz; Foken, Thomas; Wesche, Karsten; Hafner, Silke; Biermann, Tobias; Babel, Wolfgang; Gerken, Tobias; Unteregelsbacher, Sebastian; Seeber, Elke; Spielvogel, Sandra; Ingrisch, Johannes; Li, Xiaogang; Yue, Sun; Li, Qianru; Xu, Xingliang

2017-04-01

Kobresia grasslands on Tibetan Plateau have accumulated tremendous organic carbon (C) stocks, are an important grazing ground for local herdsmen, host a major portion of the regional terrestrial biodiversity, and supply large areas of SE Asia with water. All these ecosystem functions are threatened by large-scale soil degradation on the Tibetan Plateau. Nonetheless, the patterns and mechanisms of Kobresia pasture degradation, visible across the entire Tibetan Plateau, remain unknown. In the K. pygmaea core area, we studied natural and anthropogenic drivers of pasture degradation to discover new mechanisms and associated processes of soil organic carbon (SOC) loss. We show that livestock overgrazing and trampling in recent decades have triggered grassland degradation by initiating plant death and reducing grassland recovery. Combined with the harsh climate, this destroys the protective Kobresia turf. Considering these processes as well as other anthropogenic and natural drivers, a novel pasture degradation concept was developed. Pasture soils corresponding to the fiwe degradation stages were sampled and analyzed for physical, chemical and biological properties. Soil drought and frost lead to polygonal cracking of the Kobresia turf, already weakened by overgrazing. This induces gradual erosion by wind and water, extends the cracks and removes the upper carbon-enriched soil. Erosion-derived SOC losses amount to 5 kg C m-2 and are aggravated by decreasing root C input and increased SOC mineralization (both ca. 2.5 kg C m-2). Mineralization-derived SOC loss was reflected by a negative δ13C shift of SOC going from intact to severely degraded stages, and was caused by a relative enrichment of 13C-depleted lignin. In sum, degradation has released tremendous amounts of carbon back into the atmosphere as CO2, or as increased sediment load in rivers, connected with declining water quality off-site. Affected by changed local water budget, the regional clouds' formation starts

Assessment of the insulation degradation of cables used in nuclear power plants

NASA Astrophysics Data System (ADS)

Bartoníc̆ek, B.; Hnát, V.; Plac̆ek, V.

1999-05-01

Cable insulating materials are usually, during their operational lifetime, exposed to a high number of various deteriorative enviromental effects resulting in their degradation. In the case of cables used in the nuclear power plant (NPP) hermetic zone these factors consist predominantly of long-term irradiation (at rather low dose rates, in the presence of oxygen) and enhanced temperature. Hence, all cables assigned for use in NPP have to be qualified for use under such severe conditions. However, not only the initial qualification but also monitoring of the actual state of the installed cables in regular intervals is now recommended. Monitoring of the actual state of the cable insulation and the prediction of their residual service life (i.e., the on-going qualification) consist of the measurement of the properties that are directly proportional to the functionality of the cables (usually the elongation at break is used as the critical parameter). For the cables installed in the NPP hermetic zone a method based on the measurement of the thermo-oxidative stability by the differential scanning calorimetry has been developed.

The endophytic bacterium Serratia sp. PW7 degrades pyrene in wheat.

PubMed

Zhu, Xuezhu; Wang, Wanqing; Crowley, David E; Sun, Kai; Hao, Shupeng; Waigi, Michael Gatheru; Gao, Yanzheng

2017-03-01

This research was conducted to isolate polycyclic aromatic hydrocarbon-degrading (PAH-degrading) endophytic bacteria and investigate their potential in protecting plants against PAH contamination. Pyrene-degrading endophytic bacteria were isolated from plants grown in PAH-contaminated soil. Among these endophytic bacteria, strain PW7 (Serratia sp.) isolated from Plantago asiatica was selected to investigate the suppression of pyrene accumulation in Triticum aestivum L. In the in vitro tests, strain PW7 degraded 51.2% of the pyrene in the media within 14 days. The optimal biodegradation conditions were pH 7.0, 30 °C, and MS medium supplemented with additional glucose, maltose, sucrose, and peptones. In the in vivo tests, strain PW7 successfully colonized the roots and shoots of inoculated (E + ) wheat plants, and its colonization decreased pyrene accumulation and pyrene transportation from roots to shoots. Remarkably, the concentration of pyrene in shoots decreased much more than that in roots, suggesting that strain PW7 has the potential for protecting wheat against pyrene contamination and mitigating the threat of pyrene to human health via food consumption.

Chlorophyll degradation in the gut of generalist and specialist Lepidopteran caterpillars.

PubMed

Badgaa, Amarsanaa; Jia, Aiqun; Ploss, Kerstin; Boland, Wilhelm

2014-12-01

Plant feeding herbivores excrete most of the ingested chlorophyll (Chl) as partly degraded derivatives lacking the phytol side chain and the central magnesium ion. An ecological role of digested and degraded Chls in the interactions between insects, their food plant and other insects has been described recently. To gain more information on common degradation patterns in plant-feeding insects, the orals secretions and frass of five Lepidopteran caterpillars covering generalists and specialists, namely Spodoptera littoralis, Spodoptera eridania, Heliothis virescens, Helicoverpa armigera, Manduca sexta, and, for comparison, of the leaf beetle larva Chrysomela lapponica were analyzed for chlorophyll catabolites. The major degradation products were determined as pheohorbide a/b and pyropheophorbide a/b by using LC-MS, LC-NMR, UV, and fluorescence spectrometry. The compounds were not present in fresh leaves of the food plants (Phaseolus lunatus, Nicotiana tabacum). The catabolite spectrum in generalists and specialists was qualitatively similar and could be attributed to the action of gut proteins and the strongly alkaline milieu in the digestive tract. Due to the anaerobic environment of the larval gut, the tetrapyrrole core of the Chl catabolites was not cleaved. Substantial amounts of Chl a/b metabolites were strongly complexed by a protein in the mid-gut.

Impact of transverse and longitudinal dispersion on first-order degradation rate constant estimation

NASA Astrophysics Data System (ADS)

Stenback, Greg A.; Ong, Say Kee; Rogers, Shane W.; Kjartanson, Bruce H.

2004-09-01

A two-dimensional analytical model is employed for estimating the first-order degradation rate constant of hydrophobic organic compounds (HOCs) in contaminated groundwater under steady-state conditions. The model may utilize all aqueous concentration data collected downgradient of a source area, but does not require that any data be collected along the plume centerline. Using a least squares fit of the model to aqueous concentrations measured in monitoring wells, degradation rate constants were estimated at a former manufactured gas plant (FMGP) site in the Midwest U.S. The estimated degradation rate constants are 0.0014, 0.0034, 0.0031, 0.0019, and 0.0053 day -1 for acenaphthene, naphthalene, benzene, ethylbenzene, and toluene, respectively. These estimated rate constants were as low as one-half those estimated with the one-dimensional (centerline) approach of Buscheck and Alcantar [Buscheck, T.E., Alcantar, C.M., 1995. Regression techniques and analytical solutions to demonstrate intrinsic bioremediation. In: Hinchee, R.E., Wilson, J.T., Downey, D.C. (Eds.), Intrinsic Bioremediation, Battelle Press, Columbus, OH, pp. 109-116] which does not account for transverse dispersivity. Varying the transverse and longitudinal dispersivity values over one order of magnitude for toluene data obtained from the FMGP site resulted in nearly a threefold variation in the estimated degradation rate constant—highlighting the importance of reliable estimates of the dispersion coefficients for obtaining reasonable estimates of the degradation rate constants. These results have significant implications for decision making and site management where overestimation of a degradation rate may result in remediation times and bioconversion factors that exceed expectations. For a complex source area or non-steady-state plume, a superposition of analytical models that incorporate longitudinal and transverse dispersion and time may be used at sites where the centerline method would not be

Production of cell wall-degrading enzymes by Aspergillus nidulans: a model system for fungal pathogenesis of plants.

PubMed Central

Dean, R A; Timberlake, W E

1989-01-01

The cell wall-degrading enzymes polygalacturonase and pectate lyase have been suggested to be crucial for penetration and colonization of plant tissues by some fungal pathogens. We have found that Aspergillus nidulans (= Emericella nidulans), a saprophytic Ascomycete, produces levels of these enzymes equal to those produced by soft-rotting Erwinia species. Induction of polygacturonase and pectate lyase in A. nidulans requires substrate and is completely repressed by glucose. Surprisingly, inoculation of excised plant tissues with A. nidulans conidia leads to formation of necrotic, water-soaked lesions within which the organism sporulates. Thus, A. nidulans has phytopathogenic potential. The release of glucose and other sugars from wounded tissues may repress pectolytic enzyme production and limit disease development. Therefore, we tested creA204, a mutation that relieves glucose repression of some A. nidulans carbon utilization enzymes, for its effect on production of pectolytic enzymes. creA204 failed to relieve catabolite repression of polygalacturonase or pectate lyase and had no effect on disease severity. PMID:2535501

Characterization of Radiation Fields in Biological Shields of Nuclear Power Plants for Assessing Concrete Degradation

NASA Astrophysics Data System (ADS)

Remec, Igor; Rosseel, Thomas M.; Field, Kevin G.; Le Pape, Yann

2016-02-01

Life extensions of nuclear power plants to 60 and potentially 80 years of operation have renewed interest in long-term material degradation. One material being considered is concrete, with a particular focus on radiation-induced effects. Based on the projected neutron fluence values (E > 0.1 MeV) in the concrete biological shields of the US pressurized water reactor fleet and the available data on radiation effects on concrete, some decrease in mechanical properties of concrete cannot be ruled out during extended operation beyond 60 years. An expansion of the irradiated concrete database and a reliable determination of relevant neutron fluence energy cutoff value are necessary to ensure reliable risk assessment for extended operation of nuclear power plants. Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC0500OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

Bioaccumulation and degradation of pentachloronitrobenzene in Medicago sativa.

PubMed

Li, Ying Ying; Yang, Hong

2013-04-15

Pentachloronitrobenzene (PCNB) is a fungicide belonging to the organochlorine family and used extensively in agriculture for crop production. Many studies have implied that PCNB has become an environmental concern due to its widespread contamination in eco-systems. However, whether PCNB is bioaccumulated, degraded and phytotoxic in plants is poorly understood. In this study, several alfalfa (Medicago sativa) cultivars were grown in soil with PCNB to investigate their absorption and catabolism, including PCNB residues in the soil and PCNB-induced toxic responses in plants. Alfalfa plants varied widely in their ability to accumulate and degrade PCNB. The degradation rate of PCNB was 66.26-77.68% after alfalfa growth in the soils for 20 d, while the rates in the control (soil without alfalfa) were only 48.42%. Moreover, concentrations of PCNB residues in the rhizosphere soil were significantly higher than those in the non-rhizosphere soils. Alfalfa exposed to 10 mg kg(-1) PCNB showed inhibited growth and oxidative damage, but the effects of PCNB on the cultivars differed significantly, indicating that the alfalfa cultivars have different tolerance to PCNB. Activities of invertase (INV), urease (URE), polyphenol oxidase (PPO), alkaline phosphatase (ALP) and acid phosphatase (ACP) were assayed in the treated soils and showed that the enzyme activities were altered after PCNB exposure. The URE, PPO, ALP and ACP activities were increased in soil following the planting of alfalfa. The objective of the study was to analyze the potential of different cultivars of alfalfa to accumulate and degrade PCNB from the contaminated soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

Phragmites australis root secreted phytotoxin undergoes photo-degradation to execute severe phytotoxicity

PubMed Central

Rudrappa, Thimmaraju; Choi, Yong Seok; Levia, Delphis F; Legates, David R; Lee, Kelvin H

2009-01-01

Our study organism, Phragmites australis (common reed), is a unique invader in that both native and introduced lineages are found coexisting in North America. This allows one to make direct assessments of physiological differences between these different subspecies and examine how this relates to invasiveness. Recent efforts to understand plant invasive behavior show that some invasive plants secrete a phytotoxin to ward-off encroachment by neighboring plants (allelopathy) and thus provide the invaders with a competitive edge in a given habitat. Here we show that a varying climatic factor like ultraviolet (UV) light leads to photo-degradation of secreted phytotoxin (gallic acid) in P. australis rhizosphere inducing higher mortality of susceptible seedlings. The photo-degraded product of gallic acid (hereafter GA), identified as mesoxalic acid (hereafter MOA), triggered a similar cell death cascade in susceptible seedlings as observed previously with GA. Further, we detected the biological concentrations of MOA in the natural stands of exotic and native P. australis. Our studies also show that the UV degradation of GA is facilitated at an alkaline pH, suggesting that the natural habitat of P. australis may facilitate the photo-degradation of GA. The study highlights the persistence of the photo-degraded phytotoxin in the P. australis's rhizosphere and its inhibitory effects against the native plants. PMID:19816146

Isolation of mesotrione-degrading bacteria from aquatic environments in Brazil

USDA-ARS?s Scientific Manuscript database

Mesotrione is a benzoylcyclohexane-1,3-dione herbicide that inhibits 4-hydroxyphenyl pyruvate dioxygenase (HPPD) in target plants. Although it has been used since 2000, only a limited number of degrading microorganisms have been reported. Mesotrione-degrading bacteria were selected among strains iso...

Ecological Value of Native Plant Cultivars Versus Wild-Type Native Plants for Promoting Hemipteran Diversity in Suburban Areas.

PubMed

Poythress, J C; Affolter, James M

2018-04-14

Because of concerns over recent declines in overall biodiversity in suburban areas, homeowners are attempting to improve the ecological functioning of their landscapes by incorporating native plants. Native plants are important for supporting native herbivorous insects, but it is unknown whether the native plants that are commercially available, typically cultivated varieties (cultivars) of a single genotype, are equally effective as food sources as the local, wild-type plants. We compared the hemipteran communities feeding on cultivars and wild-propagated plants for four species of native perennials commonly used as ornamentals. Of 65 hemipteran species collected, 35 exhibited a preference for some plant species over others, indicating a high degree of host-plant specialization. Moreover, the insect community associated with cultivars was distinct from the insect community associated with wild-type plants for each plant species, with three to four insect species accounting for most of the observed difference. Total insect abundance and insect biomass differed between cultivars and wild-propagated plants, but the direction of the difference changed over time and was not consistent among plant species. Species richness and a diversity index (the Q statistic) did not differ between cultivars and wild-type plants. These data suggest that abundance and diversity of hemipteran insects does not depend on the source of the plant material per se, but rather on the particular characteristics of cultivars that distinguish them from the wild type.

Phytodegradation of organophosphorus compounds by transgenic plants expressing a bacterial organophosphorus hydrolase.

PubMed

Wang, Xiaoxue; Wu, Ningfeng; Guo, Jun; Chu, Xiaoyu; Tian, Jian; Yao, Bin; Fan, Yunliu

2008-01-18

Organophosphorus (OP) compounds are widely used as pesticides in agriculture but cause broad-area environmental pollution. In this work, we have expressed a bacterial organophosphorus hydrolase (OPH) gene in tobacco plants. An assay of enzyme activity showed that transgenic plants could secrete OPH into the growth medium. The transgenic plants were resistant to methyl parathion (Mep), an OP pesticide, as evidenced by a toxicity test showing that the transgenic plants produced greater shoot and root biomass than did the wild-type plants. Furthermore, at 0.02% (v/v) Mep, the transgenic plants degraded more than 99% of Mep after 14 days of growth. Our work indicates that transgenic plants expressing an OPH gene may provide a new strategy for decontaminating OP pollutants.

Grassland degradation caused by tourism activities in Hulunbuir, Inner Mongolia, China

NASA Astrophysics Data System (ADS)

Le, C.; Ikazaki, K.; Siriguleng; Kadono, A.; Kosaki, T.

2014-02-01

The recent increase in the number of tourists has raised serious concerns about grassland degradation by tourism activities in Inner Mongolia. Thus, we evaluated the effects of tourism activities on the vegetation and soil in Hulunbuir grassland. We identified all the plant species, measured the number and height of plant and plant coverage rate, and calculated species diversity, estimated above-ground biomass in use plot and non-use plot. We also measured soil hardness, and collected soil samples for physical and chemical analysis in both plots. The obtained results were as follows: a) the height of the dominant plants, plant coverage rate, species diversity, and above-ground biomass were significantly lower in use plot than in non-use plot, b) Carex duriuscula C.A.Mey., indicator plant for soil degradation, was dominant in use plot, c) soil hardness was significantly higher in use plot than in non-use plot, and spatial dependence of soil hardness was only found in the use plot, d) CEC, TC, TN and pH in the topsoil were significantly lower in use plot than non-use plot. On the basis of the results, we concluded that the tourism activities can be another major cause of the grassland degradation in Inner Mongolia.

Woody plant establishment in grassed reclamation areas of the Athabasca oil sands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedkenheuer, A.W.

1980-12-01

The primary end land use for areas disturbed by the Syncrude Canada Ltd. oil sands surface mining venture is forest cover. Short term erosion control is of concern, however, and this results in the early establishment of a grass and legume cover. Problems have subsequently been encountered in attempts to establish woody plants in the grass and legume cover. Vegetation competition for soil moisture and nutrients and rodent damage to woody seedlings have been the major problem areas. A study was initiated in 1978 to evaluate methods of manipulating the grass and legume cover sufficiently to improve success rates inmore » establishing a variety of shrubs and trees. Five replicated treatments using the chemical herbicide glyphosate, soil scarification and fire alone plus soil scarification were established on an area seeded to grass and legumes in spring 1976. Woody plant survival and rodent damage, populations and distribution are being assessed annually in spring and fall. Rodent damage to woody seedlings was heavy in fall 1978 with 80 percent of the deciduous seedlings on non-scarified plots being damaged. In June 1979, 98 percent of the deciduous plants on the control and herbicide treatment areas were damaged. Damage to conifers was approximately 30 percent less during this time. Prescribed burning and mechanical scarification substantially reduced rodent damage. Seedling survival was variable with Amelanchier alnifolia, Pinus contorta and Populus tremuloides consistently exhibiting the highest survival rates.« less

Calorimetric analysis of fungal degraded wood

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blankenhorn, P.R.; Baldwin, R.C.; Merrill, W. Jr.

1980-01-01

Endothermic transition and gross heat of combustion of aspenwood subjected to degradation by Lenzites trabea and Polyporus versicolor were determined by using differential scanning calorimetry (DSC) and an adiabatic O bomb. Endothermic peak areas of undegraded and fungi-degraded wood differed from each other at all levels of weight loss. The regression analysis of the DSC data vs. weight loss revealed a significant relations, although not highly correlated, for P. versicolor-degraded specimens and a nonsignificant relation for L. trabea-degraded specimens; weight loss and gross heat of combustion values of degraded specimens were significantly correlated.

Degradation of Lignin by Cyathus Species

PubMed Central

Abbott, Thomas P.; Wicklow, Donald T.

1984-01-01

The ability of 12 Cyathus species to degrade 14C-labeled lignin in kenaf was studied. The sum of 14C released into solution plus 14C released into the gas phase over a 32-day fermentation period was used to determine average daily rates of lignin biodegradation. Cyathus pallidus. C. africanus, and C. berkeleyanus delignified kenaf most rapidly. C. canna showed the greatest preference for lignin degradation over other plant components, and its rate of lignin degradation was only slightly lower than the three most active species. The apparent ability of fungi to metabolize low-molecular-weight lignin breakdown products correlated well with their overall delignification rates. C. stercoreus metabolized degradation products of lignin from wheat straw better than those from kenaf lignin, based on the amount of low-molecular-weight products left in solution. PMID:16346497

Lignin degradation in wood-feeding insects.

PubMed

Geib, Scott M; Filley, Timothy R; Hatcher, Patrick G; Hoover, Kelli; Carlson, John E; Jimenez-Gasco, Maria del Mar; Nakagawa-Izumi, Akiko; Sleighter, Rachel L; Tien, Ming

2008-09-02

The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut community analysis of A. glabripennis identified a single species of fungus in the Fusarium solani/Nectria haematococca species complex. This is a soft-rot fungus that may be contributing to wood degradation. These results transform our understanding of lignin degradation by wood-feeding insects.

Level area surrounding Facility 314 showing the planted ring that ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Level area surrounding Facility 314 showing the planted ring that contains the radial ground wires, note the ring beneath the antenna circles is cleared of vegetation and covered with gravel, view facing southwest - U.S. Naval Base, Pearl Harbor, Naval Radio Station, AF/FRD-10 Circularly Disposed Antenna Array, Wahiawa, Honolulu County, HI

Leaf carbohydrates influence transcriptional and post-transcriptional regulation of nocturnal carboxylation and starch degradation in the facultative CAM plant, Mesembryanthemum crystallinum.

PubMed

Taybi, Tahar; Cushman, John C; Borland, Anne M

2017-11-01

Nocturnal degradation of transitory starch is a limiting factor for the optimal function of crassulacean acid metabolism and must be coordinated with phosphoenolypyruvate carboxylase (PEPC)-mediated CO 2 uptake to optimise carbon gain over the diel cycle. The aim of this study was to test the hypothesis that nocturnal carboxylation is coordinated with starch degradation in CAM via a mechanism whereby the products of these pathways regulate diel transcript abundance and enzyme activities for both processes. To test this hypothesis, a starch and CAM-deficient mutant of Mesembryanthemum crystallinum was compared with wild type plants under well-watered and saline (CAM-inducing) conditions. Exposure to salinity increased the transcript abundance of genes required for nocturnal carboxylation, starch and sucrose degradation in both wild type and mutant, but the transcript abundance of several of these genes was not sustained over the dark period in the low-carbohydrate, CAM-deficient mutant. The diel pattern of transcript abundance for PEPC mirrored that of PEPC protein, as did the transcripts, protein, and activity of chloroplastic starch phosphorylase in both wild type and mutant, suggesting robust diel coordination of these metabolic processes. Activities of several amylase isoforms were low or lacking in the mutant, whilst the activity of a cytosolic isoform of starch phosphorylase was significantly elevated, indicating contrasting modes of metabolic regulation for the hydrolytic and phosphorylytic routes of starch degradation. Externally supplied sucrose resulted in an increase in nocturnal transcript abundance of genes required for nocturnal carboxylation and starch degradation. These results demonstrate that carbohydrates impact on transcriptional and post-transcriptional regulation of nocturnal carboxylation and starch degradation in CAM. Copyright © 2017 Elsevier GmbH. All rights reserved.

Bacterial enzymes involved in lignin degradation.

PubMed

de Gonzalo, Gonzalo; Colpa, Dana I; Habib, Mohamed H M; Fraaije, Marco W

2016-10-20

Lignin forms a large part of plant biomass. It is a highly heterogeneous polymer of 4-hydroxyphenylpropanoid units and is embedded within polysaccharide polymers forming lignocellulose. Lignin provides strength and rigidity to plants and is rather resilient towards degradation. To improve the (bio)processing of lignocellulosic feedstocks, more effective degradation methods of lignin are in demand. Nature has found ways to fully degrade lignin through the production of dedicated ligninolytic enzyme systems. While such enzymes have been well thoroughly studied for ligninolytic fungi, only in recent years biochemical studies on bacterial enzymes capable of lignin modification have intensified. This has revealed several types of enzymes available to bacteria that enable them to act on lignin. Two major classes of bacterial lignin-modifying enzymes are DyP-type peroxidases and laccases. Yet, recently also several other bacterial enzymes have been discovered that seem to play a role in lignin modifications. In the present review, we provide an overview of recent advances in the identification and use of bacterial enzymes acting on lignin or lignin-derived products. Copyright © 2016 The Author(s). Published by Elsevier B.V. All rights reserved.

Inventorization of some ayurvedic plants and their ethnomedicinal use in Kakrajhore forest area of West Bengal.

PubMed

Biswas, Soumyajit; Shaw, Rupa; Bala, Sanjay; Mazumdar, Asis

2017-02-02

Medicinal Plant resources of forest origin are extensively used in India for various systems of medicine like Ayurveda, Unani, Homeopathy, Allopathy, Siddha and Ethnic etc. The tribal communities around the Kakrajhore forest in West Medinipur district of West Bengal have their own traditional knowledge based system of curing many diseases using the forest based plant resources similar to ayurveda. The forest comprises of one of the unique treasure and rich source of diversified ethno-botanical wealth and therefore extensive studies is required for proper documentation including ethnomedicinal knowledge of local tribes. The present study was initiated with an aim to inventorize the ayurvedic medicinal plant recourses and explore the traditional knowledge of tribal people of Kakrajhore forest to treat several diseases along with the sustainable management and conservation of medicinal plants. The information on the medicinal plant resources were gathered through floristic inventorization with proper sampling method in the study area (N22°42'57.05″, E86°34'58.02″) during the year 2015. For floristic inventorization the study area of 312 ha was delineated by using GPS Receiver. Then total mapped area was divided by virtual grid of 100m apart in both East-West and North-South direction to allocate 60 sample plots by random sampling. In addition to inventorization, the use value (UV) of the species was determined and the informant consensus factor (ICF) was calculated for the medicinal plants found in the study area based on personal interview. Further exploration was carried out to establish linkage with Ayurveda. The present survey has identified 57 numbers of ethno-medicinal plants belonging to 39 families, used for preparing medicinal remedies. The habit of the plants includes 35% trees, 28% shrubs, 23% herbs and 14% climbers. The most frequently utilized plant parts were the Roots & Tuber roots (26%), Stem which includes Bark, Tubers, Bulb, Rhizome, Gum, Wood

How mycorrhizal plant-soil interactions affect formation and degradation of soil organic matter in boreal forest

NASA Astrophysics Data System (ADS)

Adamczyk, Bartosz; Sietiö, Outi-Maaria; Ahvenainen, Anu; Strakova, Petra; Heinonsalo, Jussi

2017-04-01

Forest soil organic matter (SOM) contains more carbon (C) than all the flora and atmosphere combined and that is why C release as CO2 from SOM may have drastic consequences for climate globally. SOM is enormous C sink which has the potential to become C source (IPCC 2013). To predict long-term soil C storage and climate feedbacks we need profound understanding of dynamics and drivers of SOM decomposition. Ecosystem processes associated with C cycle are constrained by C and N interactions. At the level of ecosystem boreal forest is N-limited, as most of soil N is stored in recalcitrant organic form bound or complexed with soil compounds such as polyphenols. To improve N uptake, also from less available pools, plant species form symbioses with mycorrhizal fungi able to degrade recalcitrant N and sharing it with plants. As a feedback, plants provide to fungal symbiont assimilated C. Climate change through elevated CO2 level led to increases in photosynthesis which enhance the C flow belowground accelerating N uptake by plants also from more recalcitrant N pools. Increased SOM decomposition would possibly result also in increase of CO2 production from soil. Our field experiment was conducted at Hyytiälä forestry field station (SMEAR II, University of Helsinki) located in southern Finland (61°84'N, 24°26'E). In this 3-year long experiment, we discriminated SOM decomposition with different mesh bags filled with humus. These mesh bags allowed for the entrance of mycorrhiza and fine roots (1mm mesh size), or only mycorrhiza (50µm), or both were excluded (1µm). We followed changes in SOM content, N pools and enzymatic activity. The results suggests that plant-mycorrhiza interactions increase recalcitrant pool of organic N in SOM due to root-derived tannins, but mycorrhizal plants have still access to this N. Although mycorrhizal plant-soil interaction seems to strongly affect the formation of recalcitrant SOM, the net decomposition is not hindered by these chemical

Air pollution impedes plant-to-plant communication, but what is the signal?

PubMed

Blande, James D; Li, Tao; Holopainen, Jarmo K

2011-07-01

Since the first reports that undamaged plants gain defensive benefits following exposure to damaged neighbors, the idea that plants may signal to each other has attracted much interest. There has also been substantial debate concerning the ecological significance of the process and the evolutionary drivers. Part of this debate has centered on the distance over which signaling between plants occurs in nature. In a recent study we showed that an ozone concentration of 80 ppb, commonly encountered in nature, significantly reduces the distance over which plant-plant signaling occurs in lima bean. We went on to show that degradation of herbivore-induced plant volatiles by ozone is the likely mechanism for this. The key question remaining from our work was that if ozone is degrading the signal in transit between plants, which chemicals are responsible for transmitting the signal in purer air? Here we present the results of a small scale experiment testing the role of the two most significant herbivore-induced terpenes and discuss our results in terms of other reported functions for these chemicals in plant-plant signaling.

Geospatial tools for assessing land degradation in Budgam district, Kashmir Himalaya, India

NASA Astrophysics Data System (ADS)

Rashid, Mehnaz; Lone, Mahjoor Ahmad; Romshoo, Shakil Ahmad

2011-06-01

Land degradation reduces the ability of the land to perform many biophysical and chemical functions. The main aim of this study was to determine the status of land degradation in the Budgam area of Kashmir Himalaya using remote sensing and geographic information system. The satellite data together with other geospatial datasets were used to quantify different categories of land degradation. The results were validated in the field and an accuracy of 85% was observed. Land use/land cover of the study area was determined in order to know the effect of land use on the rate of land degradation. Normalized differential vegetation index (NDVI) and slope of the area were determined using LANDSAT-enhanced thematic mapper plus (ETM+) data, advanced space borne thermal emission and reflection radiometer, and digital elevation model along with other secondary data were analysed to create various thematic maps, viz., land use/land cover, geology, NDVI and slopes used in modelling land degradation in the Kashmir Himalayan region. The vegetation condition, elevation and land use/land cover information of the area were integrated to assess the land degradation scenario in the area using the ArcGIS `Spatial Analyst Module'. The results reveal that about 13.19% of the study area has undergone moderate to high degradation, whereas about 44.12% of the area has undergone slight degradation.

Plant n-alkane production from litterfall altered the diversity and community structure of alkane degrading bacteria in litter layer in lowland subtropical rainforest in Taiwan

NASA Astrophysics Data System (ADS)

Huang, Tung-Yi; Hsu, Bing-Mu; Chao, Wei-Chun; Fan, Cheng-Wei

2018-03-01

n-Alkane and alkane-degrading bacteria have long been used as crucial biological indicators of paleoecology, petroleum pollution, and oil and gas prospecting. However, the relationship between n-alkane and alkane-degrading bacteria in natural forests is still poorly understood. In this study, long-chain n-alkane (C14-C35) concentrations in litterfall, litter layer, and topsoil as well as the diversity and abundance of n-alkane-degrading bacterial communities in litter layers were investigated in three habitats across a lowland subtropical rainforest in southern Taiwan: ravine, windward, and leeward habitats in Nanjenshan. Our results demonstrate that the litterfall yield and productivity of long-chain n-alkane were highest in the ravine habitats. However, long-chain n-alkane concentrations in all habitats were decreased drastically to a similar low level from the litterfall to the bulk soil, suggesting a higher rate of long-chain n-alkane degradation in the ravine habitat. Operational taxonomic unit (OTU) analysis using next-generation sequencing data revealed that the relative abundances of microbial communities in the windward and leeward habitats were similar and different from that in the ravine habitat. Data mining of community amplicon sequencing using the NCBI database revealed that alkB-gene-associated bacteria (95 % DNA sequence similarity to alkB-containing bacteria) were most abundant in the ravine habitat. Empirical testing of litter layer samples using semi-quantitative polymerase chain reaction for determining alkB gene levels confirmed that the ravine habitat had higher alkB gene levels than the windward and leeward habitats. Heat map analysis revealed parallels in pattern color between the plant and microbial species compositions of the habitats, suggesting a causal relationship between the plant n-alkane production and microbial community diversity. This finding indicates that the diversity and relative abundance of microbial communities in the

Evaluation of areas prepared for planting using LANDSAT data. M.S. Thesis; [Ribeirao Preto, Brazil

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Deassuncao, G. V.; Duarte, V.

1983-01-01

Three different algorithms (SINGLE-CELL, MAXVER and MEDIA K) were used to automatically interpret data from LANDSAT observations of an area of Ribeirao Preto, Brazil. Photographic transparencies were obtained, projected and visually interpreted. The results show that: (1) the MAXVER algorithm presented a better classification performance; (2) verification of the changes in cultivated areas using data from the three different acquisition dates was possible; (3) the water bodies, degraded lands, urban areas, and fallow fields were frequently mistaken by cultivated soils; and (4) the use of projected photographic transparencies furnished satisfactory results, besides reducing the time spent on the image-100 system.

Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2: an experiment with plant populations from naturally high CO2 areas.

PubMed

van Loon, Marloes P; Rietkerk, Max; Dekker, Stefan C; Hikosaka, Kouki; Ueda, Miki U; Anten, Niels P R

2016-06-01

The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant-plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may benefit more from [CO2] elevation than others. The relative contribution of plastic (within the plant's lifetime) and genotypic (over several generations) responses to elevated [CO2] on plant performance was investigated and how these patterns are modified by plant-plant interactions was analysed. Plantago asiatica seeds originating from natural CO2 springs and from ambient [CO2] sites were grown in mono stands of each one of the two origins as well as mixtures of both origins. In total, 1944 plants were grown in [CO2]-controlled walk-in climate rooms, under a [CO2] of 270, 450 and 750 ppm. A model was used for upscaling from leaf to whole-plant photosynthesis and for quantifying the influence of plastic and genotypic responses. It was shown that changes in canopy photosynthesis, specific leaf area (SLA) and stomatal conductance in response to changes in growth [CO2] were mainly determined by plastic and not by genotypic responses. We further found that plants originating from high [CO2] habitats performed better in terms of whole-plant photosynthesis, biomass and leaf area, than those from ambient [CO2] habitats at elevated [CO2] only when both genotypes competed. Similarly, plants from ambient [CO2] habitats performed better at low [CO2], also only when both genotypes competed. No difference in performance was found in mono stands. The results indicate that natural selection under increasing [CO2] will be mainly driven by competitive interactions. This supports the notion that plant-plant interactions have an important influence on future vegetation functioning and species distribution. Furthermore, plant performance was mainly driven by plastic and not by genotypic responses to changes in

Bacterial cellulose hydrolysis in anaerobic environmental subsystems--Clostridium thermocellum and Clostridium stercorarium, thermophilic plant-fiber degraders.

PubMed

Zverlov, Vladimir V; Schwarz, Wolfgang H

2008-03-01

Cellulose degradation is a rare trait in bacteria. However, the truly cellulolytic bacteria are extremely efficient hydrolyzers of plant cell wall polysaccharides, especially those in thermophilic anaerobic ecosystems. Clostridium stercorarium, a thermophilic ubiquitous soil dweller, has a simple cellulose hydrolyzing enzyme system of only two cellulases. However, it seems to be better suited for the hydrolysis of a wide range of hemicelluloses. Clostridium thermocellum, an ubiquitous thermophilic gram-type positive bacterium, is one of the most successful cellulose degraders known. Its extracellular enzyme complex, the cellulosome, was prepared from C. thermocellum cultures grown on cellulose, cellobiose, barley beta-1,3-1,4-glucan, or a mixture of xylan and cellulose. The single proteins were identified by peptide chromatography and MALDI-TOF-TOF. Eight cellulosomal proteins could be found in all eight preparations, 32 proteins occur in at least one preparation. A number of enzymatic components had not been identified previously. The proportion of components changes if C. thermocellum is grown on different substrates. Mutants of C. thermocellum, devoid of scaffoldin CipA, that now allow new types of experiments with in vitro cellulosome reassembly and a role in cellulose hydrolysis are described. The characteristics of these mutants provide strong evidence of the positive effect of complex (cellulosome) formation on hydrolysis of crystalline cellulose.

Solar photo-degradation of a pharmaceutical wastewater effluent in a semi-industrial autonomous plant.

PubMed

Expósito, Antonio J; Durán, Antonio; Monteagudo, José M; Acevedo, Alba

2016-05-01

An industrial wastewater effluent coming from a pharmaceutical laboratory has been treated in a semi-industrial autonomous solar compound parabolic collector (CPC) plant. A photo-Fenton process assisted with ferrioxalate has been used. Up to 79% of TOC can be removed in 2 h depending on initial conditions when treating an aqueous effluent containing up to 400 ppm of initial organic carbon concentration (TOC). An initial ratio of Fe(II)/TOC higher than 0.5 guarantees a high removal. It can be seen that most of TOC removal occurs early in the first hour of reaction. After this time, mineralization was very slow, although H2O2 was still present in solution. Indeed it decomposed to form oxygen in inefficient reactions. It is clear that remaining TOC was mainly due to the presence of acetates which are difficult to degrade. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification and expression profiling of novel plant cell wall degrading enzymes from a destructive pest of palm trees, Rhynchophorus ferrugineus.

PubMed

Antony, B; Johny, J; Aldosari, S A; Abdelazim, M M

2017-08-01

Plant cell wall degrading enzymes (PCWDEs) from insects were recently identified as a multigene family of proteins that consist primarily of glycoside hydrolases (GHs) and carbohydrate esterases (CEs) and play essential roles in the degradation of the cellulose/hemicellulose/pectin network in the invaded host plant. Here we applied transcriptomic and degenerate PCR approaches to identify the PCWDEs from a destructive pest of palm trees, Rhynchophorus ferrugineus, followed by a gut-specific and stage-specific differential expression analysis. We identified a total of 27 transcripts encoding GH family members and three transcripts of the CE family with cellulase, hemicellulase and pectinase activities. We also identified two GH9 candidates, which have not previously been reported from Curculionidae. The gut-specific quantitative expression analysis identified key cellulases, hemicellulases and pectinases from R. ferrugineus. The expression analysis revealed a pectin methylesterase, RferCE8u02, and a cellulase, GH45c34485, which showed the highest gut enriched expression. Comparison of PCWDE expression patterns revealed that cellulases and pectinases are significantly upregulated in the adult stages, and we observed specific high expression of the hemicellulase RferGH16c4170. Overall, our study revealed the potential of PCWDEs from R. ferrugineus, which may be useful in biotechnological applications and may represent new tools in R. ferrugineus pest management strategies. © 2017 The Royal Entomological Society.

[Aerosol size distribution of organic carbon and elemental carbon on the top of coke oven and in the plant area].

PubMed

Liu, Xiao-Feng; Peng, Lin; Bai, Hui-Ling; Mu, Ling; Song, Chong-Fang

2013-08-01

In order to investigate the characteristic of organic carbon (OC) and elemental carbon (EC) in particles on the top of coke oven and in the plant area, the particle matter samples of five size fraction including < or = 1.4 microm, 1.4-2.1 microm, 2.1-4.2 microm, 4.2-10.2 microm and > or = 10.2 microm were collected using Staplex234 cascade impactor, and OC and EC were analyzed by Elementar Analysensysteme GmbH vario EL cube. The mass concentrations of OC and EC associated with TSP on the top of coke oven were 291.6 microg x m(-3) and 255.1 microg x m(-3), while those in the plant area were 377.8 microg x m(-3) and 151.7 microg x m(-3). The mass concentration of secondary organic carbon (SOC) in particles with size of < or = 1.4 microm was 147.3 microg x m(-3) in the plant area. The value of OC/EC in particles less than 2.1 microm was 1.3 on the top of coke oven. The mass concentration of EC in TSP in the plant area was lower than that on the top of coke oven, while the mass concentration of OC in the plant area was significantly higher than that on the top of coke oven. The mass concentrations of OC and EC associated with particles less than 10.2 microm in the plant area were far higher than those in the atmosphere of area where the coke plant is located. The OC and EC in particles, which were collected both on the top of coke oven and in the plant area, were mainly enriched in fine particles. The size distribution of OC showed a clear distinction between the coke oven top and the plant area, which revealed that OC in the plant area was more preferably enriched in fine particles than that on the top of coke oven, and the same size distribution of EC was found on the top of coke oven and in the plant area. In the plant area, the mass concentration of SOC and the contribution of SOC to OC increased with the decreasing diameter in particles with diameter of less than 10.2 microm.

Is phytoremediation a sustainable and reliable approach to clean-up contaminated water and soil in Alpine areas?

PubMed

Schwitzguébel, Jean-Paul; Comino, Elena; Plata, Nadia; Khalvati, Mohammadali

2011-07-01

Phytoremediation does exploit natural plant physiological processes and can be used to decontaminate agricultural soils, industrial sites, brownfields, sediments and water containing inorganic and organic pollutants or to improve food chain safety by phytostabilisation of toxic elements. It is a low-cost and environment friendly technology targetting removal, degradation or immobilisation of contaminants. The aim of the present review is to highlight some recent advances in phytoremediation in the Alpine context. Case studies are presented where phytoremediation has been or can be successfully applied in Alpine areas to: (1) clean-up industrial wastewater containing sulphonated aromatic xenobiotics released by dye and textile industries; (2) remediate agricultural soils polluted by petroleum hydrocarbons; (3) improve food chain safety in soils contaminated with toxic trace elements (As, Co, Cr and Pb); and (4) treat soils impacted by modern agricultural activities with a special emphasis on phosphate fertilisation. Worlwide, including in Alpine areas, the controlled use of appropriate plants is destined to play a major role for remediation and restoration of polluted and degraded ecosystems, monitoring and assessment of environmental quality, prevention of landscape degradation and immobilisation of trace elements. Phytotechnologies do already offer promising approaches towards environmental remediation, human health, food safety and sustainable development for the 21st century in Alpine areas and elsewhere all over the world.

Rapid determination of leaf area and plant height by using light curtain arrays in four species with contrasting shoot architecture

PubMed Central

2014-01-01

Background Light curtain arrays (LC), a recently introduced phenotyping method, yield a binary data matrix from which a shoot silhouette is reconstructed. We addressed the accuracy and applicability of LC in assessing leaf area and maximum height (base to the highest leaf tip) in a phenotyping platform. LC were integrated to an automated routine for positioning, allowing in situ measurements. Two dicotyledonous (rapeseed, tomato) and two monocotyledonous (maize, barley) species with contrasting shoot architecture were investigated. To evaluate if averaging multiple view angles helps in resolving self-overlaps, we acquired a data set by rotating plants every 10° for 170°. To test how rapid these measurements can be without loss of information, we evaluated nine scanning speeds. Leaf area of overlapping plants was also estimated to assess the possibility to scale this method for plant stands. Results The relation between measured and calculated maximum height was linear and nearly the same for all species. Linear relations were also found between plant leaf area and calculated pixel area. However, the regression slope was different between monocotyledonous and dicotyledonous species. Increasing the scanning speed stepwise from 0.9 to 23.4 m s−1 did not affect the estimation of maximum height. Instead, the calculated pixel area was inversely proportional to scanning speed. The estimation of plant leaf area by means of calculated pixel area became more accurate by averaging consecutive silhouettes and/or increasing the angle between them. Simulations showed that decreasing plant distance gradually from 20 to 0 cm, led to underestimation of plant leaf area owing to overlaps. This underestimation was more important for large plants of dicotyledonous species and for small plants of monocotyledonous ones. Conclusions LC offer an accurate estimation of plant leaf area and maximum height, while the number of consecutive silhouettes that needs to be averaged is species

Rapid determination of leaf area and plant height by using light curtain arrays in four species with contrasting shoot architecture.

PubMed

Fanourakis, Dimitrios; Briese, Christoph; Max, Johannes Fj; Kleinen, Silke; Putz, Alexander; Fiorani, Fabio; Ulbrich, Andreas; Schurr, Ulrich

2014-04-11

Light curtain arrays (LC), a recently introduced phenotyping method, yield a binary data matrix from which a shoot silhouette is reconstructed. We addressed the accuracy and applicability of LC in assessing leaf area and maximum height (base to the highest leaf tip) in a phenotyping platform. LC were integrated to an automated routine for positioning, allowing in situ measurements. Two dicotyledonous (rapeseed, tomato) and two monocotyledonous (maize, barley) species with contrasting shoot architecture were investigated. To evaluate if averaging multiple view angles helps in resolving self-overlaps, we acquired a data set by rotating plants every 10° for 170°. To test how rapid these measurements can be without loss of information, we evaluated nine scanning speeds. Leaf area of overlapping plants was also estimated to assess the possibility to scale this method for plant stands. The relation between measured and calculated maximum height was linear and nearly the same for all species. Linear relations were also found between plant leaf area and calculated pixel area. However, the regression slope was different between monocotyledonous and dicotyledonous species. Increasing the scanning speed stepwise from 0.9 to 23.4 m s-1 did not affect the estimation of maximum height. Instead, the calculated pixel area was inversely proportional to scanning speed. The estimation of plant leaf area by means of calculated pixel area became more accurate by averaging consecutive silhouettes and/or increasing the angle between them. Simulations showed that decreasing plant distance gradually from 20 to 0 cm, led to underestimation of plant leaf area owing to overlaps. This underestimation was more important for large plants of dicotyledonous species and for small plants of monocotyledonous ones. LC offer an accurate estimation of plant leaf area and maximum height, while the number of consecutive silhouettes that needs to be averaged is species-dependent. A constant scanning

Toxic metal tolerance in native plant species grown in a vanadium mining area.

PubMed

Aihemaiti, Aikelaimu; Jiang, Jianguo; Li, De'an; Li, Tianran; Zhang, Wenjie; Ding, Xutong

2017-12-01

Vanadium (V) has been extensively mined in China and caused soil pollution in mining area. It has toxic effects on plants, animals and humans, posing potential health risks to communities that farm and graze cattle adjacent to the mining area. To evaluate in situ phytoremediation potentials of native plants, V, chromium, copper and zinc concentrations in roots and shoots were measured and the bioaccumulation (BAF) and translocation (TF) efficiencies were calculated. The results showed that Setaria viridis accumulated greater than 1000 mg kg -1 V in its shoots and exhibited TF > 1 for V, Cr, Zn and BAF > 1 for Cu. The V accumulation amount in the roots of Kochia scoparia also surpassed 1000 mg kg -1 and showed TF > 1 for Zn. Chenopodium album had BAF > 1 for V and Zn and Daucus carota showed TF > 1 for Cu. Eleusine indica presented strong tolerance and high metal accumulations. S. viridis is practical for in situ phytoextractions of V, Cr and Zn and phytostabilisation of Cu in V mining area. Other species had low potential use as phytoremediation plant at multi-metal polluted sites, but showed relatively strong resistance to V, Cr, Cu and Zn toxicity, can be used to vegetate the contaminated soils and stabilise toxic metals in V mining area.

Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species.

PubMed

Prospere, Kurt; McLaren, Kurt P; Wilson, Byron

2016-10-01

The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species

NASA Astrophysics Data System (ADS)

Prospere, Kurt; McLaren, Kurt P.; Wilson, Byron

2016-10-01

The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

Plant Diversity Contributions of Riparian Areas in Watersheds of the Northern Lake States, USA

Treesearch

P. Charles Goebel; Brain J. Palik; Kurt S. Pregitzer

2003-01-01

In most forested watersheds, riparian areas constitute a small proportion of the total land area, yet their contributions to overall plant diversity can be significant. However, little information is available on which portion of riparian areas (defined as functional ecotones comprising all fluvial landforms, including floodplains, terraces, and connecting hillslopes)...

Cumulative effects of climate change and ice-wedge degradation, Prudhoe Bay oilfield Alaska

NASA Astrophysics Data System (ADS)

Walker, D. A.; Kanevskiy, M. Z.; Shur, Y.; Raynolds, M. K.; Buchhorn, M.

2016-12-01

Development of Arctic oil & gas resources requires extensive networks of roads, pipelines and other forms of infrastructure. The Prudhoe Bay Oilfield is the largest Arctic oilfield in North America with a long, well-documented history. In a previous publication we analyzed the historical record of high-resolution aerial photos to document the long-term changes to infrastructure extent (1949-2010) for the entire oilfield, and an integrated-geoecological-historical-change-mapping (IGHCM) approach to document terrain changes within 22-km2 areas of the oilfield. We reported the recent widespread expansion of thermokarst, starting in about 1989. Here we examine the annual air-photo record to better pinpoint the years of major change. We also conducted detailed field studies of roadside changes using topographic surveys and soil, vegetation and ice-wedge coring studies. Both sites exhibit extensive ice-wedge degradation that is caused by a combination of a long-term warming trend a series of exceptionally warm summers, and infrastructure-related factors that melted the tops of ice wedges. Near-road thermokarst is enhanced by warmer soils associated with road dust, roadside flooding, near-road pipelines, communication cables, and altered snow regimes. These strongly affect roadside ecosystems and the infrastructure itself. Changes to ecosystems include altered hydrology with the drying of polygon centers and the formation of well-developed high-centered polygons occurs in some areas. Other areas develop extensive flooding and erosion of ice-wedge troughs. An unexpected result of flooding is the stabilization of ice-wedge degradation in some areas because the increased productivity of sedges in the flooded areas is producing large amounts of organic material that protects the tops of ice wedges from further degradation. The large increases in productivity in roadside areas also attract large flocks of waterfowl. Changes to the soils with the addition of thick layers of

The Effects of Degradational Factors on the Ecosystem of Mount Madra

NASA Astrophysics Data System (ADS)

Efe, R.; Soykan, A.; Sönmez, S.; Cürebal, I.

2009-04-01

Significant degradation has been observed in Turkey's Mediterranean woodlands and mountainous areas. Mediterranean climate prevails in the southern and western part of Turkey. Mount Madra, which is located on Turkey's western Aegean coast, is part of a rangeland which is particularly exposed to the effects of degradation resulting from human activities. The principal factors in the degradation are inappropriate land use, destruction of forests, mining, construction, overgrazing and transhumance. Mount Madra and its environs benefit from a Mediterranean climate, experiencing dry, hot summers and cool, wet winters. The average yearly rainfall is 700-1000 mm, of which most occurs in the winter months. The mountain extends from east to west, and between the South and North slopes there is great variety in terms of plant species and biodiversity. The regeneration of the lost plant cover has been hindered by the mountain's geomorphologic characteristics. The slopes have suffered destruction of vegetation and, as a result of severe erosion, the soil has been swept away and in many places the bedrock has become exposed. The Kozak plateau on mount Madra is notable for the richness of its natural vegetation. This plateau, covered in pine forest (Pinus pinea), is the site for the traditional transhumance of over 500 families. Pine nuts and livestock breeding are livelihood of these families. Mount Madra and its surrounding area is one of the most important locations with gold mining potential in Turkey and it is estimated that it has 16.7 tons of gold reserve. The gold mining which took place on the west of the Madra Mountain around Ovacik village in 1994 led to serious land degradation in the surrounding area. The new mining on the study area and the proposed feldspar mining on the Madra riverbed poses a serious threat to the region's ecosystem and biodiversity. The removal of increasing amounts of granite and other quarrying has had a negative impact on the natural

Remedial investigation concept plan for the groundwater operable units at the chemical plant area and the ordnance works area, Weldon Spring, Missouri

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1999-07-15

The U.S. Department of Energy (DOE) and the U.S. Department of the Army (DA) are conducting cleanup activities at two properties--the DOE chemical plant area and the DA ordnance works area (the latter includes the training area)--located in the Weldon Spring area in St. Charles County, Missouri. These areas are on the National Priorities List (NPL), and cleanup activities at both areas are conducted in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. DOE and DA are conducting a joint remedial investigation (RI) and baseline risk assessment (BRA) as part of the remedial investigation/feasibility studymore » (RI/FS) for the groundwater operable units for the two areas. This joint effort will optimize further data collection and interpretation efforts and facilitate overall remedial decision making since the aquifer of concern is common to both areas. A Work Plan issued jointly in 1995 by DOE and the DA discusses the results of investigations completed at the time of preparation of the report. The investigations were necessary to provide an understanding of the groundwater system beneath the chemical plant area and the ordnance works area. The Work Plan also identifies additional data requirements for verification of the evaluation presented.« less

Rhizobial characterization in revegetated areas after bauxite mining.

PubMed

Borges, Wardsson Lustrino; Prin, Yves; Ducousso, Marc; Le Roux, Christine; de Faria, Sergio Miana

2016-01-01

Little is known regarding how the increased diversity of nitrogen-fixing bacteria contributes to the productivity and diversity of plants in complex communities. However, some authors have shown that the presence of a diverse group of nodulating bacteria is required for different plant species to coexist. A better understanding of the plant symbiotic organism diversity role in natural ecosystems can be extremely useful to define recovery strategies of environments that were degraded by human activities. This study used ARDRA, BOX-PCR fingerprinting and sequencing of the 16S rDNA gene to assess the diversity of root nodule nitrogen-fixing bacteria in former bauxite mining areas that were replanted in 1981, 1985, 1993, 1998, 2004 and 2006 and in a native forest. Among the 12 isolates for which the 16S rDNA gene was partially sequenced, eight, three and one isolate(s) presented similarity with sequences of the genera Bradyrhizobium, Rhizobium and Mesorhizobium, respectively. The richness, Shannon and evenness indices were the highest in the area that was replanted the earliest (1981) and the lowest in the area that was replanted most recently (2006). Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Assessing and Understanding Trail Degradation: Results from Big South Fork National River and Recreational Area

USGS Publications Warehouse

Marion, J.L.; Olive, N.

2006-01-01

This report describes results from a comprehensive assessment of resource conditions on a large (24%) sample of the trail system within Big South Fork National River and Recreational Area (BSF). Components include research to develop state-of-knowledge trail impact assessment and monitoring methods, application of survey methods to BSF trails, analysis and summary of results, and recommendations for trail management decision making and future monitoring. Findings reveal a trail system with some substantial degradation, particularly soil erosion, which additionally threatens water quality in areas adjacent to streams and rivers. Factors that contribute to or influence these problems are analyzed and described. Principal among these are trail design factors (trail topographic position, soil texture, grade and slope alignment angle), use-related factors (type and amount of use), and maintenance factors (water drainage). Recommendations are offered to assist managers in improving the sustainability of the trails system to accommodate visitation while enhancing natural resource protection.

Assessment of potential indigenous plant species for the phytoremediation of arsenic-contaminated areas of Bangladesh.

PubMed

Mahmud, Rezwanul; Inoue, Naoto; Kasajima, Shin-Ya; Shaheen, Riffat

2008-01-01

Soil and water contaminated with arsenic (As) pose a major environmental and human health problem in Bangladesh. Phytoremediation, a plant-based technology, may provide an economically viable solution for remediating the As-polluted sites. The use of indigenous plants with a high tolerance and accumulation capacity for As may be a very convenient approach for phytoremediation. To assess the potential of native plant species for phytoremediation, plant and soil samples were collected from four As-contaminated (groundwater) districts in Bangladesh. The main criteria used for selecting plants for phytoremediation were high bioconcentration factors (BCFs) and translocation factors (TFs) of As. From the results of a screening of 49 plant species belonging to 29 families, only one species of fern (Dryopteris filix-mas), three herbs (Blumea lacera, Mikania cordata, and Ageratum conyzoides), and two shrubs (Clerodendrum trichotomum and Ricinus communis) were found to be suitable for phytoremediation. Arsenic bioconcentration and translocation factors > 1 suggest that these plants are As-tolerant accumulators with potential use in phytoextraction. Three floating plants (Eichhornia crassipes, Spirodela polyrhiza, and Azolla pinnata) and a common wetland weed (Monochoria vaginalis) also showed high BCF and TF values; therefore, these plants may be promising candidates for cleaningup As-contaminated surface water and wetland areas. The BCF of Oryza sativa, obtained from As-contaminated districts was > 1, which highlights possible food-chain transfer issues for As-contaminated areas in Bangladesh.

Removal Action Decision Document Alabama Army Ammunition Plant. Area A

DTIC Science & Technology

1988-01-01

Feasibility Study. Environmental Science and Engineering (ESE), 1986. 0 Alabama Army Ammunition Plant Remedial Investigation. Environmental Science and...had already been cleaned up and released for industrial use and was not included in the Feasibility Study conducted by Environmental Science and...criteria. The I contaminated soil was excavated and stored in the temporary storage structures in Area B. REFERENCES 1. Environmental Science and

Investigations of microbial degradation of polycyclic aromatic hydrocarbons based on 13C-labeled phenanthrene in a soil co-contaminated with trace elements using a plant assisted approach.

PubMed

Wawra, Anna; Friesl-Hanl, Wolfgang; Jäger, Anna; Puschenreiter, Markus; Soja, Gerhard; Reichenauer, Thomas; Watzinger, Andrea

2018-03-01

Co-contaminations of soils with organic and inorganic pollutants are a frequent environmental problem. Due to their toxicity and recalcitrance, the heterogeneous pollutants may persist in soil. The hypothesis of this study was that degradation of polycyclic aromatic hydrocarbons (PAHs) is enhanced if heavy metals in soil are immobilized and their bioavailability reduced. For metal immobilization and enhanced biodegradation, distinct mineral and organic soil amendments (iron oxides, gravel sludge, biochar) were deployed in an incubation batch experiment. The second part of the experiment consisted of a greenhouse pot experiment applying fast-growing and pollution-tolerant woody plants (willow and black locust). Soil amendments initially immobilized NH 4 NO 3 -extractable zinc, cadmium, and lead; after 100 days of incubation, soil amendments showed reductions only for cadmium and a tendency to enhance arsenic mobility. In order to monitor the remediation success, a 13 C-phenanthrene (PHE) label was applied. 13 C-phospholipid fatty acid analysis ( 13 C-PLFA) further enabled the identification of PHE-degrading soil microorganisms. Both experiments exhibited a similar PLFA profile. Gram-negative bacteria (esp. cy17:0, 16:1ω7 + 6, 18:1ω7c) were the most significant microbial group taking up 13 C-PHE. Plants effectively increased the label uptake by gram-positive bacteria and increased the biomass of the fungal biomarker, although their contribution to the degradation process was minor. Plants tended to prolong PAH dissipation in soil; at the end of the experiment, however, all treatments showed equally low total PAH concentrations in soil. While black locust plants tended not to take up potentially toxic trace elements, willows accumulated them in their leaves. The results of this study show that the chosen treatments did not enhance the remediation of the experimental soil.

Delayed expression of SAGs correlates with longevity in CMS wheat plants compared to its fertile plants.

PubMed

Semwal, Vimal Kumar; Singh, Bhupinder; Khanna-Chopra, Renu

2014-04-01

Reproductive sinks regulate monocarpic senescence in crop plants. Monocarpic senescence was studied in wheat fertile (cv. HW 2041) and its isonuclear cytoplasmic male sterile (CMS) line. CMS plants exhibited slower rate of senescence accompanied by longer green leaf area duration and slower deceleration in chlorophyll, protein content, PN and rubisco content coupled with lower protease activities than fertile (F) plants. CMS plants also exhibited lower ROS levels and less membrane damage than F plants. CMS plants maintained better antioxidant defense, less oxidative damage in chloroplast and higher transcript levels of both rbcL and rbcS genes during senescence than F plants. F plants exhibited early induction and higher expression of SAGs like serine and cysteine proteases, glutamine synthetases GS1 and GS2, WRKY53 transcription factor and decline in transcript levels of CAT1 and CAT2 genes than CMS plants. Hence, using genetically fertile and its CMS line of wheat it is confirmed that delayed senescence in the absence of reproductive sinks is linked with slower protein oxidation, rubisco degradation and delayed activation of SAGs. Better antioxidant defense in chloroplasts at later stages of senescence was able to mitigate the deleterious effects of ROS in CMS plants. We propose that delayed increase in ROS in cytoplasmic male sterile wheat plants resulted in delayed activation of WRKY53, SAGs and the associated biochemical changes than fertile plants.

Mercury uptake and phytotoxicity in terrestrial plants grown naturally in the Gumuskoy (Kutahya) mining area, Turkey.

PubMed

Sasmaz, Merve; Akgül, Bunyamin; Yıldırım, Derya; Sasmaz, Ahmet

2016-01-01

This study investigated mercury (Hg) uptake and transport from the soil to different plant parts by documenting the distribution and accumulation of Hg in the roots and shoots of 12 terrestrial plant species, all of which grow naturally in surface soils of the Gumuskoy Pb-Ag mining area. Plant samples and their associated soils were collected and analyzed for Hg content by ICP-MS. Mean Hg values in the soils, roots, and shoots of all plants were 6.914, 460, and 206 µg kg(-1), respectively and lower than 1. The mean enrichment factors for the roots (ECR) and shoots (ECS) of these plants were 0.06 and 0.09, respectively and lower than 1. These results show that the roots of the studied plants prevented Hg from reaching the aerial parts of the plants. The mean translocation factor (TLF) was 1.29 and higher than 1. The mean TLF values indicated that all 12 plant species had the ability to transfer Hg from the roots to the shoots but that transfer was more efficient in plants with higher ECR and ECS. Therefore, these plants could be useful for the biomonitoring of environmental pollution and for rehabilitating areas contaminated by Hg.

Wilderness ecology: virgin plant communities of the Boundary Waters Canoe Area.

Treesearch

Lewis F. Ohmann; Robert R. Ream

1971-01-01

Describes virgin plant communities in the Boundary Waters Canoe Area. Data from all vegetative components of 106 virgin upland stands were used to construct a community classification through a combination of agglomerative clustering and principal components analysis. Discusses the relation of communities to their environment and to past wildfires.

Herbicide and degradate flux in the Yazoo River Basin

USGS Publications Warehouse

Coupe, R.H.; Welch, H.L.; Pell, A.B.; Thurman, E.M.

2005-01-01

During 1996-1997, water samples were collected from five sites in the Yazoo River Basin and analysed for 14 herbicides and nine degradates. These included acetochlor, alachlor, atrazine, cyanazine, fluometuron, metolachlor, metribuzin, molinate, norflurazon, prometryn, propanil, propazine, simazine, trifluralin, three degradates of fluometuron, two degradates of atrazine, one degradate of cyanazine, norflurazon, prometryn, and propanil. Fluxes generally were higher in 1997 than in 1996 due to a greater rainfall in 1997 than 1996. Fluxes were much larger from streams in the alluvial plain (an area of very productive farmland) than from the Skuna River in the bluff hills (an area of small farms, pasture, and forest). Adding the flux of the atrazine degradates to the atrazine flux increased the total atrazine flux by an average of 14.5%. The fluometuron degradates added about 10% to the total fluometuron flux, and adding the norflurazon degradate flux to the norflurazon flux increased the flux by 82% in 1996 and by 171% in 1997. ?? 2005 Taylor & Francis.

Soil degradation in wooded rangelands of southwest Spain

NASA Astrophysics Data System (ADS)

Schnabel, S.; Lavado Contador, J. F.; Gómez Gutiérrez, Á.

2009-04-01

Extremadura, gullies are localized and permanent features, representing only a small fraction of the total land and are mainly located in valley bottoms with an alluvial sediment fill. Individual gullies may present high soil losses, constitute an obstacle for traffic and enhance drainage of subsurface flow (valley bottoms probably dry up more quickly). They are more frequent on schist and greywacke than on granites, the dominant rock types in SW Spain. Monitoring of a gully system during a period of 7 years has shown that a strong relationship exists between catchment hydrology (rainfall and runoff) and erosion in the channel. However, a study of the same gully system for the period from 1947 until 2002 has shown increases of erosion during a period when large parts of the catchment were cultivated and when livestock numbers were increased. The latter is mainly related with animal trampling in the vicinity and along the margins of the gully. Rill erosion is not a frequent phenomenon in dehesa, limited mainly to areas which are ploughed for cultivation or shrub cleaning. Very high erosion may occur when tillage practice immediately precedes exceptional rainstorms. Other soil degradation processes important in wooded rangelands are soil compaction, reduction of organic matter content, biological activity, plant available water and infiltration capacity. The few quantitative data available to date show that in large parts of the region soils are degraded (shallow, low organic matter content and high bulk density, etc.). This can be the result of centuries of agrosilvopastoral land use but is certainly also the consequence of inadequate land management in many areas at present. The large spatial variation of factors (vegetation, soils, relief, climate, land use and land management) is a characteristic feature of wooded rangelands in the Iberian Peninsula, and together with the temporal changes of these factors, makes it very difficult to discriminate the causes of soil

[Study on species and distribution of flora of national rare and endangered medicinal plant in the Three Gorges area].

PubMed

Chen, Shao-Cheng

2013-04-01

According to the China Plant Red Data Book and National Key Protected Wild Plants, the distribution of the rare and endangered plants and national conservative plants in the Three Gorges area were investigated and statistically analyzed. Its floristic composition and characteristics of geographical distribution were explored. As a result, a total of 97 species of medicinal flora belonging to rare and endangered national protection plants were found in the Three Gorges area. They come from 81 genera of 46 families. Their vertical distribution is obvious and horizontal distribution has discontinuous overlap. There are many ancient relict medicinal plants in the Three Gorges area. These medicinal plants have obvious temperate characteristics, and are easily found at warm and moist ravines and hillsides; The proportion of tree is much higher than that of herb, vine, shrub and fern. Most of them belong to specific and monotypic genera.

Hydroxyapatite degradation and biocompatibility

NASA Astrophysics Data System (ADS)

Wang, Haibo

Hydroxyapatite (HA) is widely used as a bioactive ceramics since it forms a chemical bonding to bone. The disadvantage of this material is its poor mechanical properties. HA can be degraded in body, which is the reason for its bioactivity, but too fast degradation rate could cause negative effects, such as macrophage present, particle generation, and even implant clinical failure. HA degradation rate will be greatly changed under many conditions: purity, HA form (i.e. bulk form, porous form, coating, or HA/polymer composites), microstructure, implant site, body conditions, etc. Although much work has been done in HA properties and application areas, the HA degradation behavior and mechanism under these different conditions are still not clear. In this research, three aspects of HA degradation have been studied: (1) Two very common impurities---Tri-Calcium Phosphate (TCP) and Calcium Oxide and their influences on HA degradation in vitro and in vivo, (2) influence of HA/polymer composite form on HA degradation, (3) HA material particle generation and related mechanism. From the in vitro and in vivo tests on bulk HA disks with various Ca/P ratios, HA degradation can clearly be found. The degradation level is different in different Ca/P ratio samples as well as in different test environments. In same test environment, non-stoichiometric HA samples have higher degradation rate than stoichiometric HA. HA/PMMA composite design successfully intensifies HA degradation both in vitro and in vivo. Grain boundary damage can be found on in vivo test samples, which has not been clearly seen on bulk HA degraded surface. HA particle generation is found in in vitro and in vivo HA/PMMA composite surface and in vivo bulk HA surface. Sintering temperature and time does affect HA grain size, and this affect HA degradation rate. Intergranular fracture is found in a several micron zone close to the Ca/P ratio 1.62 and 1.67 sample degraded surfaces. At Ca/P ratio greater than 1.667, after

Photo-fenton degradation of diclofenac: identification of main intermediates and degradation pathway.

PubMed

Pérez-Estrada, Leónidas A; Malato, Sixto; Gernjak, Wolfgang; Agüera, Ana; Thurman, E Michael; Ferrer, Imma; Fernández-Alba, Amadeo R

2005-11-01

In recent years, the presence of pharmaceuticals in the aquatic environment has been of growing interest. These new contaminants are important because many of them are not degraded under the typical biological treatments applied in the wastewater treatment plants and represent a continuous input into the environment. Thus, compounds such as diclofenac are present in surface waters in all Europe and a crucial need for more enhanced technologies that can reduce its presence in the environment has become evident. In this sense, advanced oxidation processes (AOPs) represent a good choice for the treatment of hazardous nonbiodegradable pollutants. This work deals with the solar photodegradation of diclofenac, an antiinflammatory drug, in aqueous solutions by photo-Fenton reaction. A pilot-scale facility using a compound parabolic collector (CPC) reactor was used for this study. Results obtained show rapid and complete oxidation of diclofenac after 60 min, and total mineralization (disappearance of dissolved organic carbon, DOC) after 100 min of exposure to sunlight. Although diclofenac precipitates during the process at low pH, its degradation takes place in the homogeneous phase governed by a precipitation-redissolution-degradation process. Establishment of the reaction pathway was made possible by a thorough analysis of the reaction mixture identifying the main intermediate products generated. Gas chromatography-mass spectrometry (GC/ MS) and liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOF-MS) were used to identify 18 intermediates, in two tentative degradation routes. The main one was based on the initial hydroxylation of the phenylacetic acid moiety in the C-4 position and subsequent formation of a quinone imine derivative that was the starting point for further multistep degradation involving hydroxylation, decarboxylation, and oxidation reactions. An alternative route was based on the transient preservation of the biphenyl amino moiety

Predicting the presence and cover of management relevant invasive plant species on protected areas.

PubMed

Iacona, Gwenllian; Price, Franklin D; Armsworth, Paul R

2016-01-15

Invasive species are a management concern on protected areas worldwide. Conservation managers need to predict infestations of invasive plants they aim to treat if they want to plan for long term management. Many studies predict the presence of invasive species, but predictions of cover are more relevant for management. Here we examined how predictors of invasive plant presence and cover differ across species that vary in their management priority. To do so, we used data on management effort and cover of invasive plant species on central Florida protected areas. Using a zero-inflated multiple regression framework, we showed that protected area features can predict the presence and cover of the focal species but the same features rarely explain both. There were several predictors of either presence or cover that were important across multiple species. Protected areas with three days of frost per year or fewer were more likely to have occurrences of four of the six focal species. When invasive plants were present, their proportional cover was greater on small preserves for all species, and varied with surrounding household density for three species. None of the predictive features were clearly related to whether species were prioritized for management or not. Our results suggest that predictors of cover and presence can differ both within and across species but do not covary with management priority. We conclude that conservation managers need to select predictors of invasion with care as species identity can determine the relationship between predictors of presence and the more management relevant predictors of cover. Copyright © 2015 Elsevier Ltd. All rights reserved.

Distribution and accumulation of selenium in wild plants growing naturally in the Gumuskoy (Kutahya) mining area, Turkey.

PubMed

Sasmaz, Merve; Akgül, Bunyamin; Sasmaz, Ahmet

2015-05-01

This study investigated selenium uptake and transport from the soil to 12 plant species in the mining area of Gumuskoy (Kutahya), Turkey. Plant samples and their associated soils were collected and analyzed for Se content by ICP-MS. Mean Se values in the soils, roots, and shoots of all plants were 0.9, 0.6, and 0.8 mg kg(-1), respectively. The mean enrichment coefficients for roots (ECR) and shoots (ECS) of these plants were 0.78 and 0.97. The mean translocation factors (TLF) were 1.33. These values indicate that all 12 plant species had the ability to transfer Se from the roots to the shoot, but that transfer was more efficient in plants with higher ECR and ECS. Therefore, these plants may be useful in phytoremediation in rehabilitating areas contaminated by Se because their ECR, ECS and TLFs are >1.

Inspection of Nuclear Power Plant Containment Structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graves, H.L.; Naus, D.J.; Norris, W.E.

1998-12-01

Safety-related nuclear power plant (NPP) structures are designed to withstand loadings from a number of low-probability external and interval events, such as earthquakes, tornadoes, and loss-of-coolant accidents. Loadings incurred during normal plant operation therefore generally are not significant enough to cause appreciable degradation. However, these structures are susceptible to aging by various processes depending on the operating environment and service conditions. The effects of these processes may accumulate within these structures over time to cause failure under design conditions, or lead to costly repair. In the late 1980s and early 1990s several occurrences of degradation of NPP structures were discoveredmore » at various facilities (e.g., corrosion of pressure boundary components, freeze- thaw damage of concrete, and larger than anticipated loss of prestressing force). Despite these degradation occurrences and a trend for an increasing rate of occurrence, in-service inspection of the safety-related structures continued to be performed in a somewhat cursory manner. Starting in 1991, the U.S. Nuclear Regulatory Commission (USNRC) published the first of several new requirements to help ensure that adequate in-service inspection of these structures is performed. Current regulatory in-service inspection requirements are reviewed and a summary of degradation experience presented. Nondestructive examination techniques commonly used to inspect the NPP steel and concrete structures to identify and quantify the amount of damage present are reviewed. Finally, areas where nondestructive evaluation techniques require development (i.e., inaccessible portions of the containment pressure boundary, and thick heavily reinforced concrete sections are discussed.« less

Oligogalacturonide-mediated induction of a gene involved in jasmonic acid synthesis in response to the cell-wall-degrading enzymes of the plant pathogen Erwinia carotovora.

PubMed

Norman, C; Vidal, S; Palva, E T

1999-07-01

Identification of Arabidopsis thaliana genes responsive to plant cell-wall-degrading enzymes of Erwinia carotovora subsp. carotovora led to the isolation of a cDNA clone with high sequence homology to the gene for allene oxide synthase, an enzyme involved in the biosynthesis of jasmonates. Expression of the corresponding gene was induced by the extracellular enzymes from this pathogen as well as by treatment with methyl jasmonate and short oligogalacturonides (OGAs). This suggests that OGAs are involved in the induction of the jasmonate pathway during plant defense response to E. carotovora subsp. carotovora attack.

ENZYMATIC PROCESSES USED BY PLANTS TO DEGRADE ORGANIC COMPOUNDS

EPA Science Inventory

This is a review of recent plant enzyme systems that have been studied in uptake and transformation of organic contaminants. General procedures of plant preparation and enzyme isolation are covered. Six plant enzyme systems have been investigated for activity with selected pollut...

[Distribution pattern of rare plants along riparian zone and its implication for conservation in Shennongjia area].

PubMed

Jiang, Mingxi; Deng, Hongbing; Cai, Qinghua

2002-11-01

Due to the importance of riparian zone in maintaining and protecting regional biodiversity, more and more ecologists paid their attentions to riparian zone, and had been aware of the important effects of riparian zone in basic study and practical management. In this study, forty sampling belts (10 m x 100 m) parallel to the bank of Xiangxi River at different elevations in Shennongjia area were selected to investigate the riparian vegetation and rare plants. Fourteen species of rare plants were found in riparian zone, accounting for 42.4% of total rare plant species in Shennongjia area. The main distribution range of the fourteen rare plant species was the mixed evergreen and deciduous broadleaved forest at elevation of 1200-1800 m, where species diversity of plant community was the maximum at the moderate elevation. Fourteen rare plant species could be divided into three groups against the elevation, namely low elevation species group, moderate elevation species group, and high elevation group. In the paper, the authors discussed the reasons forming the distribution pattern of rare plant species, and pointed out the important function of riparian zone on rare plant species protection.

Large-area experiment on uptake of metals by twelve plants growing in soils contaminated with multiple metals.

PubMed

Lai, Hung-Yu; Juang, Kai-Wei; Chen, Zueng-Sang

2010-01-01

A site in central Taiwan with an area of 1.3 ha and contaminated with Cr, Cu, Ni, and Zn was selected to examine the feasibility of phytoextraction. Based on the results of a preexperiment at this site, a total of approximately 20,000 plants of 12 species were selected from plants of 33 tested species to be used in a large-area phytoextraction experiment at this site. A comparison with the initial metal concentration of 12 plant species before planting demonstrated that most species accumulated significant amounts of Cr, Cu, Ni, and Zn in their shoots after growing in this contaminated site for 31 d. Among the 12 plant species, the following accumulated higher concentrations of metals in their shoots; Garden canna and Garden verbena (45-60 mg Cr kg(-1)), Chinese ixora and Kalanchoe (30 mg Cu kg(-1)), Rainbow pink and Sunflower (30 mg Ni kg(-1)), French marigold and Sunflower (300-470 mg Zn kg(-1)). The roots of the plants of most of the 12 plant species can accumulate higher concentrations of metals than the shoots and extending the growth period promotes accumulation in the shoots. Large-area experiments demonstrated that phytoextraction is a feasible method to enable metal-contaminated soil in central Taiwan to be reused.

Polonium-210 in the environment around a radioactive waste disposal area and phosphate ore processing plant.

PubMed

Arthur, W J; Markham, O D

1984-04-01

Polonium-210 concentrations were determined for soil, vegetation and small mammal tissues collected at a solid radioactive waste disposal area, near a phosphate ore processing plant and at two rural areas in southeastern Idaho. Polonium concentrations in media sampled near the radioactive waste disposal facility were equal to or less than values from rural area samples, indicating that disposal of solid radioactive waste at the Idaho National Engineering Laboratory Site has not resulted in increased environmental levels of polonium. Concentrations of 210Po in soils, deer mice hide and carcass samples collected near the phosphate processing plant were statistically (P less than or equal to 0.05) greater than the other sampling locations; however, the mean 210Po concentration in soils and small mammal tissues from sampling areas near the phosphate plant were only four and three times greater, respectively, than control values. No statistical (P greater than 0.05) difference was observed for 210Po concentrations in vegetation among any of the sampling locations.

Lysine 206 in Arabidopsis phytochrome A is the major site for ubiquitin-dependent protein degradation.

PubMed

Rattanapisit, Kaewta; Cho, Man-Ho; Bhoo, Seong Hee

2016-02-01

Phytochrome A (phyA) is a light labile phytochrome that mediates plant development under red/far-red light condition. Degradation of phyA is initiated by red light-induced phyA-ubiquitin conjugation through the 26S proteasome pathway. The N-terminal of phyA is known to be important in phyA degradation. To determine the specific lysine residues in the N-terminal domain of phyA involved in light-induced ubiquitination and protein degradation, we aligned the amino acid sequence of the N-terminal domain of Arabidopsis phyA with those of phyA from other plant species. Based on the alignment results, phytochrome over-expressing Arabidopsis plants were generated. In particular, wild-type and mutant (substitutions of conserved lysines by arginines) phytochromes fused with GFP were expressed in phyA(-)211 Arabidopsis plants. Degradation kinetics of over-expressed phyA proteins revealed that degradation of the K206R phyA mutant protein was delayed. Delayed phyA degradation of the K206R phyA mutant protein resulted in reduction of red-light-induced phyA-ubiquitin conjugation. Furthermore, seedlings expressing the K206R phyA mutant protein showed an enhanced phyA response under far-red light, resulting in inhibition of hypocotyl elongation as well as cotyledon opening. Together, these results suggest that lysine 206 is the main lysine for rapid ubiquitination and protein degradation of Arabidopsis phytochrome A. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Microcosm studies of subsurface PAH-degrading bacteria from a former manufactured gas plant

NASA Astrophysics Data System (ADS)

Durant, Neal D.; Wilson, Liza P.; Bouwer, Edward J.

1995-01-01

A study was conducted to evaluate the potential for natural in situ biodegradation of polycyclic aromatic hydrocarbons (PAH's) in the subsurface at the site of a former manufactured gas plant. Fifty-seven samples of unconsolidated subsurface sediments were aseptically obtained from five boreholes across the site. Bacteria capable of aerobically degrading PAH's without an acclimation period were detected throughout shallow (2.7 m) and deep (24.7 m) areas of the subsurface in both relatively clean (<20 μg L -1 naphthalene) and contaminated (4400 μg L -1 naphthalene) zones. Significant ( p < 0.05) quantities of naphthalene (8±3% to 43±7%) and/or phenanthrene (3±1% to 31±3%) were mineralized in sediment-groundwater microcosms during 4 weeks of aerobic incubation at 22°C. Three samples out of 11 were able to aerobically mineralize significant quantities of benzene (6±2% to 24±1%). Of 11 samples tested for anaerobic mineralization, naphthalene biodegradation (7±1% to 13±2%) in the presence of N03 was observed in two samples. Compound removals were first order with respect to substrate concentration during the first 10-15 days of incubation. Compound biodegradation plateaued in the later stages of incubation (15-40 days), most likely from diminishing bioavailability and nutrient and oxygen depletion. Population densities in the sediments were typically low, with viable aerobic counts ranging from 0 to 10 5 CFU gdw -1, viable anaerobic counts ranging from 0 to 104 CFU gdw -1, and total counts (AODC) usually 10-fold greater than viable counts. Total counts exhibited a strong ( p < 0.01) positive correlation with sample grain size. Viable aerobic and anaerobic populations commonly occurred in the same sample, suggesting the presence of facultative anaerobes. Bacteria were metabolically active in samples from groundwaters with low pH (3.7) and high naphthalene concentrations (11,000 μg L -1). Data from these enumeration and microcosm studies suggest that natural

[Study of extracting Peucedanum praeruptorum planted area in Ningguo of Anhui province based on multi-source and multi-phase image].

PubMed

Shi, Ting-Ting; Zhang, Xiao-Bo; Zhang, Ke; Guo, Lan-Ping; Huang, Lu-Qi

2017-11-01

The herbs used as the material for traditional Chinese medicine are always planted in the mountainous area where the natural environment is suitable. As the mountain terrain is complex and the distribution of planting plots is scattered, the traditional survey method is difficult to obtain accurate planting area. It is of great significance to provide decision support for the conservation and utilization of traditional Chinese medicine resources by studying the method of extraction of Chinese herbal medicine planting area based on remote sensing and realizing the dynamic monitoring and reserve estimation of Chinese herbal medicines. In this paper, taking the Peucedanum praeruptorum planted area in Ningguo prefecture of Anhui province as an example, the multispectral remote sensing images that include Landsat-8 with a 30 m resolution and China-made GF-1 with a 16 m resolution were used as data source. Since the spectral characteristics of P. praeruptorum in the two periods are different from those of other crops, the changes of the images at two stages in the same year could be used to extract the P. praeruptorum planted area intercropped in cultivated land. Then the texture and spectral characteristics of young pecan trees were used to extract the P. praeruptorum planted area intercropped in woodland. The results showed that the extracted area of planted P. praeruptorum with the original imagery of 30 m spatial resolution and 16 m spatial resolution was 25 635.43,24 585.43 mu, respectively. Copyright© by the Chinese Pharmaceutical Association.

Transgenic plants for enhanced biodegradation and phytoremediation of organic xenobiotics.

PubMed

Abhilash, P C; Jamil, Sarah; Singh, Nandita

2009-01-01

Phytoremediation--the use of plants to clean up polluted soil and water resources--has received much attention in the last few years. Although plants have the inherent ability to detoxify xenobiotics, they generally lack the catabolic pathway for the complete degradation of these compounds compared to microorganisms. There are also concerns over the potential for the introduction of contaminants into the food chain. The question of how to dispose of plants that accumulate xenobiotics is also a serious concern. Hence the feasibility of phytoremediation as an approach to remediate environmental contamination is still somewhat in question. For these reasons, researchers have endeavored to engineer plants with genes that can bestow superior degradation abilities. A direct method for enhancing the efficacy of phytoremediation is to overexpress in plants the genes involved in metabolism, uptake, or transport of specific pollutants. Furthermore, the expression of suitable genes in root system enhances the rhizodegradation of highly recalcitrant compounds like PAHs, PCBs etc. Hence, the idea to amplify plant biodegradation of xenobiotics by genetic manipulation was developed, following a strategy similar to that used to develop transgenic crops. Genes from human, microbes, plants, and animals are being used successfully for this venture. The introduction of these genes can be readily achieved for many plant species using Agrobacterium tumefaciens-mediated plant transformation or direct DNA methods of gene transfer. One of the promising developments in transgenic technology is the insertion of multiple genes (for phase 1 metabolism (cytochrome P450s) and phase 2 metabolism (GSH, GT etc.) for the complete degradation of the xenobiotics within the plant system. In addition to the use of transgenic plants overexpressed with P450 and GST genes, various transgenic plants expressing bacterial genes can be used for the enhanced degradation and remediation of herbicides, explosives

Plant imports, Phytophthoras, and forest degradation

Treesearch

Clive Brasier

2013-01-01

Numerous 'exotic' tree pathogens are arriving in Europe, North America, and elsewhere due to flaws in current international plant health sanitary and phytosanitary (SPS) protocols. These include lack of protection against the many organisms unknown to science, an emphasis on promoting trade rather than promoting environmental biosecurity, a steadily...

[Climatic suitability of spring maize planted in the "sickle bend" area of China and regulation suggestion].

PubMed

Mao, Liu Xi; Zhao, Jun Fang; Xu, Ling Ling; Yan, Hao; Li, Sen; Li, Ya Fei

2016-12-01

The "sickle bend" area is a typical dry farming and excellent livestock development area, with fragile ecological environment. It includes 13 provinces (autonomous regions) in the north and the southwest of China. The climate suitability and the climatic potential productivity of spring maize from 1981 to 2010 in this area were quantitatively assessed. The daily data from 650 meteorological stations and grid data (1 km×1 km) in the "sickle bend" area from 1981 to 2010, and recognized indicators of agricultural meteorology were used in this study. The agro-ecological zoning mo-del (AEZ) which was currently very popular in estimating crop climatic potential productivity internationally was also applied, as well as land use classification information monitoring from satellite remote sensing. Then, based on biological characteristics of spring maize and agricultural climate resources, scientific countermeasures on reasonably adjusting agricultural production structure in subsuitable and unsuitable areas were proposed. The results showed that: 1) the climatic potential productivity of spring maize in the northern growing areas showed the "big-medium-smaller-small" distribution pattern from the east to the west from 1981 to 2010. However, the climatic potential productivity of spring maize in the southern growing areas had no significant distribution law, fluctuating between "smaller" and " medium " in general. 2) It presented the "most suitable-suitable-subsuitable-unsuitable" distribution pattern from the southeast to the northwest in the northern maize growing region of the "sickle bend" area on the whole from 1981 to 2010. In contrast, the southern planting area showed the "unsuitable-subsuitable-suitable-most suitable" distribution pattern from the southeast to the northwest. The most suitable and suitable planting areas of spring maize were mainly located in the most areas of Northeast China and North China, and the southeastern areas of Northwest China. The

PHYTOREMEDIATION OF PERCHLORATE BY TOBACCO PLANTS

EPA Science Inventory

Previous studies have shown that tobacco plants are tolerant of perchlorate and will accumulate perchlorate in the plant tissues. The objective of this research was to determine the effectiveness of tobacco plants in phytoremediation, a technology that employs plants to degrade,...

Degradation Dynamics and Dietary Risk Assessments of Two Neonicotinoid Insecticides during Lonicera japonica Planting, Drying, and Tea Brewing Processes.

PubMed

Fang, Qingkui; Shi, Yanhong; Cao, Haiqun; Tong, Zhou; Xiao, Jinjing; Liao, Min; Wu, Xiangwei; Hua, Rimao

2017-03-01

The degradation dynamics and dietary risk assessments of thiamethoxam and thiacloprid during Lonicera japonica planting, drying, and tea brewing processes were systematically investigated using high-performance liquid chromatography. The half-lives of thiamethoxam and thiacloprid were 1.0-4.1 d in the honeysuckle flowers and leaves, with degradation rate constants k ranging from -0.169 to -0.696. The safety interval time was 7 d. The sun- and oven-drying (70 °C) percent digestions were 59.4-81.0% for the residues, which were higher than the shade- and oven-drying percentages at lower temperatures (30, 40, 50, and 60 °C, which ranged from 37.7% to 57.0%). The percent transfers of thiamethoxam and thiacloprid were 0-48.4% and 0-25.2%, respectively, for the different tea brewing conditions. On the basis of the results of this study, abiding by the safety interval time is important, and using reasonable drying methods and tea brewing conditions can reduce the transfer of thiamethoxam and thiacloprid to humans.

Degradation of euptox A by tannase-producing rumen bacteria from migratory goats.

PubMed

Sharma, D; Mal, G; Kannan, A; Bhar, R; Sharma, R; Singh, B

2017-11-01

The gut microbiota capable of degrading plant biomass and antinutritional phytometabolites are of immense importance. This study reports isolation and characterization of tannase-producing rumen bacteria that could also degrade euptox A (9-oxo-10,11-dehydroageraphorone) present in Eupatorium adenophorum (Spreng). Migratory Gaddi goats were selected as source of inoculums for isolating rumen bacteria with ability to produce tannase which catalyses degradation of hydrolysable tannins (HTs). Three rumen bacterial isolates producing tannase were studied, and identified as Klebsiella variicola strain PLP G-17 LC, K. variicola strain PLP S-18 and Klebsiella pneumoniae strain PLP G-17 SC. The isolates exhibited optimal tannase activity at 40°C, and pH 6·0. The bacteria could also degrade euptox A, a potent hepatotoxin in E. adenophorum Spreng, a widely distributed noxious weed. The rumen bacteria could degrade antinutritional HTs and euptox A. Culture-independent metagenomic interventions are envisioned to completely decipher the rumen microbial ecology and exploit its genetic and metabolic potential. The bacteria producing tannase which catalyses degradation of HTs, and concurrently degrading euptox A, may have potential as microbial feed additives to increase utilization of plant biomass containing antinutritional phytometabolites. © 2017 The Society for Applied Microbiology.

Land-Use History and Contemporary Management Inform an Ecological Reference Model for Longleaf Pine Woodland Understory Plant Communities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brudvig, Lars A.; Orrock, John L.; Damschen, Ellen I.

Ecological restoration is frequently guided by reference conditions describing a successfully restored ecosystem; however, the causes and magnitude of ecosystem degradation vary, making simple knowledge of reference conditions insufficient for prioritizing and guiding restoration. Ecological reference models provide further guidance by quantifying reference conditions, as well as conditions at degraded states that deviate from reference conditions. Many reference models remain qualitative, however, limiting their utility. We quantified and evaluated a reference model for southeastern U.S. longleaf pine woodland understory plant communities. We used regression trees to classify 232 longleaf pine woodland sites at three locations along the Atlantic coastal plainmore » based on relationships between understory plant community composition, soils lol(which broadly structure these communities), and factors associated with understory degradation, including fire frequency, agricultural history, and tree basal area. To understand the spatial generality of this model, we classified all sites together. and for each of three study locations separately. Both the regional and location-specific models produced quantifiable degradation gradients–i.e., progressive deviation from conditions at 38 reference sites, based on understory species composition, diversity and total cover, litter depth, and other attributes. Regionally, fire suppression was the most important degrading factor, followed by agricultural history, but at individual locations, agricultural history or tree basal area was most important. At one location, the influence of a degrading factor depended on soil attributes. We suggest that our regional model can help prioritize longleaf pine woodland restoration across our study region; however, due to substantial landscape-to-landscape variation, local management decisions should take into account additional factors (e.g., soil attributes). Our study demonstrates the

Assessment of organochlorine pesticides residues in higher plants from oil exploration areas of Niger Delta, Nigeria.

PubMed

Sojinu, O Samuel; Sonibare, Oluwadayo O; Ekundayo, Olusegun O; Zeng, Eddy Y

2012-09-01

The concentrations and distributions of organochlorine pesticides (OCPs) in some higher plant samples collected from oil exploration areas of the Niger Delta, Nigeria were examined. The concentrations of Σ(25)OCP ranged from 82 to 424, 44 to 200 , 34 to 358, 33 to 106 and 16 to 75 ng/g in Olomoro, Oginni, Uzere, Irri and Calabar plants, respectively. The compositional profiles of the analysed OCPs in most of the plants showed no fresh inputs in the area. The OCPs detected in the samples could have resulted from pesticide usage for intense farming activities cum the use of pesticides to control household pests and insects in the area. Drilling fluids and corrosion inhibitors used in petroleum explorations also have chlorinated compounds as additives thereby serving as potential sources of OCPs. Among the studied plants, elephant grass showed high bioaccumulation and phytoremediation potentials of OCPs. The ΣHCH concentrations exceeded the allowable daily intake limit thereby serving as potential threat to humans. Copyright © 2012 Elsevier B.V. All rights reserved.

Innovative empirical approaches for inferring climate-warming impacts on plants in remote areas.

PubMed

De Frenne, Pieter

2015-02-01

The prediction of the effects of climate warming on plant communities across the globe has become a major focus of ecology, evolution and biodiversity conservation. However, many of the frequently used empirical approaches for inferring how warming affects vegetation have been criticized for decades. In addition, methods that require no electricity may be preferred because of constraints of active warming, e.g. in remote areas. Efforts to overcome the limitations of earlier methods are currently under development, but these approaches have yet to be systematically evaluated side by side. Here, an overview of the benefits and limitations of a selection of innovative empirical techniques to study temperature effects on plants is presented, with a focus on practicality in relatively remote areas without an electric power supply. I focus on methods for: ecosystem aboveground and belowground warming; a fuller exploitation of spatial temperature variation; and long-term monitoring of plant ecological and microevolutionary changes in response to warming. An evaluation of the described methodological set-ups in a synthetic framework along six axes (associated with the consistency of temperature differences, disturbance, costs, confounding factors, spatial scale and versatility) highlights their potential usefulness and power. Hence, further developments of new approaches to empirically assess warming effects on plants can critically stimulate progress in climate-change biology.

Pesticides residues and metals in plant products from agricultural area of Belgrade, Serbia.

PubMed

Ethorđević, Tijana; Ethurović, Rada

2012-03-01

The objective of study was to assess the levels of selected metals and pesticides in plant products from agricultural area of Belgrade, Serbia in order to indicate their possible sources and risks of contamination and to evaluate their sanitary probity and safety. The concentrations of cadmium, copper, iron, manganese, nickel, lead and zinc were below limits established by national and international regulations (maximum found concentrations were 0.028, 1.91, 11.16, 1.77, 0.605, 0.073 and 1.76 mg kg(-1) respectively). Only residue of one of examined pesticides was found in amount below MRL (bifenthrin 2.46 μg kg(-1)) in only one of analysed samples, while others were below detection limits. Obtained results indicate that crops from examined agricultural areas are unpolluted by contaminants used for plant protection and nutrition, indicating good agricultural practice regarding pesticides and fertilizer usage as well as moderate industrial production within examined areas.