International Institute of Higher Education, Zittau

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Zittau, Germany
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Reinecke J.,Senckenberg Museum of Natural History Gorlitz | Reinecke J.,International Institute of Higher Education, Zittau | Troeva E.,Russian Academy of Sciences | Wesche K.,Senckenberg Museum of Natural History Gorlitz | And 2 more authors.
Phytocoenologia | Year: 2017

Aims: Isolated outposts of eastern steppe vegetation (Cleistogenetea squarrosae and physiognomically related syntaxa) can be found on south-exposed slopes in the tundra and taiga zone of northern Siberia. They are considered relics of the Pleistocene cold steppe, but a number of Russian geobotanical studies reveal how these steppes differ among each other in floristic composition and environmental conditions. We aim at providing an overview of current phytosociology of northern Siberian steppes and co-occurring temperate grasslands through literature review and classification of our own data. Study area: Central and northeastern Yakutia, Russia. Methods: Phytosociological classification of 210 relevés of meadow, steppe and tundra steppe vegetation using the Braun-Blanquet approach; samples were further characterized using macro- and microclimatic variables. Results: We found true steppes of the Stipetalia krylovii up to Central Yakutia and meadow steppes of the Festucetalia lenensis as far as northeastern Yakutia. Both are restricted to south-exposed slopes, with slope steepness increasing towards the north, compensating for a colder and wetter macroclimate. Both orders include typical (Stipetum krylovii, Pulsatillietum flavescentis) and petrophytic (Elymus reflexiaristatus community, Carici duriusculae-Festucetum lenensis) associations or communities, with meadow steppes additionally containing a unique cryophytic association (Astragalo pseudoadsurgenti-Calamagrostietum purpurascentis). So called tundra steppes occur north of the tree line. They belong to the class Carici rupestris-Kobresietea bellardii, and their occurrence is more related to disturbance than to slope exposure or inclination. Conclusions: Steppe vegetation of the Cleistogenetea squarrosae occurs as far north as the taiga zone of northeastern Yakutia, but tundra steppes are not steppes in the true sense, despite similar physiognomy and the contribution of xerophytes. This distinction is important when trying to find modern analogues of Pleistocene cold steppes. © 2017 Gebrüder Borntraeger, 70176 Stuttgart, Germany.


Carro J.,CSIC - Biological Research Center | Rodriguez L.,CSIC - Biological Research Center | Prieto A.,CSIC - Biological Research Center | Serrano A.,CSIC - Biological Research Center | And 7 more authors.
FEBS Journal | Year: 2015

Oxidative conversion of 5-hydroxymethylfurfural (HMF) is of biotechnological interest for the production of renewable (lignocellulose-based) platform chemicals, such as 2,5-furandicarboxylic acid (FDCA). To the best of our knowledge, the ability of fungal aryl-alcohol oxidase (AAO) to oxidize HMF is reported here for the first time, resulting in almost complete conversion into 2,5-formylfurancarboxylic acid (FFCA) in a few hours. The reaction starts with alcohol oxidation, yielding 2,5-diformylfuran (DFF), which is rapidly converted into FFCA by carbonyl oxidation, most probably without leaving the enzyme active site. This agrees with the similar catalytic efficiencies of the enzyme with respect to oxidization of HMF and DFF, and its very low activity on 2,5-hydroxymethylfurancarboxylic acid (which was not detected by GC-MS). However, AAO was found to be unable to directly oxidize the carbonyl group in FFCA, and only modest amounts of FDCA are formed from HMF (most probably by chemical oxidation of FFCA by the H2O2 previously generated by AAO). As aldehyde oxidation by AAO proceeds via the corresponding geminal diols (aldehyde hydrates), the various carbonyl oxidation rates may be related to the low degree of hydration of FFCA compared with DFF. The conversion of HMF was completed by introducing a fungal unspecific heme peroxygenase that uses the H2O2 generated by AAO to transform FFCA into FDCA, albeit more slowly than the previous AAO reactions. By adding this peroxygenase when FFCA production by AAO has been completed, transformation of HMF into FDCA may be achieved in a reaction cascade in which O2 is the only co-substrate required, and water is the only by-product formed. © 2014 The Authors. FEBS Journal published by John Wiley & Sons Ltd on behalf of FEBS.


PubMed | CSIC - Biological Research Center, International Institute of Higher Education, Zittau and CSIC - Institute of Natural Resources and Agriculture Biology of Seville
Type: Journal Article | Journal: The FEBS journal | Year: 2015

Oxidative conversion of 5-hydroxymethylfurfural (HMF) is of biotechnological interest for the production of renewable (lignocellulose-based) platform chemicals, such as 2,5-furandicarboxylic acid (FDCA). To the best of our knowledge, the ability of fungal aryl-alcohol oxidase (AAO) to oxidize HMF is reported here for the first time, resulting in almost complete conversion into 2,5-formylfurancarboxylic acid (FFCA) in a few hours. The reaction starts with alcohol oxidation, yielding 2,5-diformylfuran (DFF), which is rapidly converted into FFCA by carbonyl oxidation, most probably without leaving the enzyme active site. This agrees with the similar catalytic efficiencies of the enzyme with respect to oxidization of HMF and DFF, and its very low activity on 2,5-hydroxymethylfurancarboxylic acid (which was not detected by GC-MS). However, AAO was found to be unable to directly oxidize the carbonyl group in FFCA, and only modest amounts of FDCA are formed from HMF (most probably by chemical oxidation of FFCA by the H2 O2 previously generated by AAO). As aldehyde oxidation by AAO proceeds via the corresponding geminal diols (aldehyde hydrates), the various carbonyl oxidation rates may be related to the low degree of hydration of FFCA compared with DFF. The conversion of HMF was completed by introducing a fungal unspecific heme peroxygenase that uses the H2 O2 generated by AAO to transform FFCA into FDCA, albeit more slowly than the previous AAO reactions. By adding this peroxygenase when FFCA production by AAO has been completed, transformation of HMF into FDCA may be achieved in a reaction cascade in which O2 is the only co-substrate required, and water is the only by-product formed.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-TP | Phase: KBBE.2012.3.5-02 | Award Amount: 3.93M | Year: 2012

In BIOCLEAN project, novel and robust microorganisms (aerobic and anaerobic bacteria, and fungi) able to extensively degrade polyethylene (PE), polypropylene (PP), polystyrol (PS) and polyvinyl chloride (PVC) polymers and plastics will be isolated from actual-site aged plastic wastes obtained from several European marine and terrestrial sites, composting facilities and landfills, and obtained via tailored screenings from existing European collections of microbes. Robust enzymes able to fragment the target plastics with the production of valuable chemicals and building blocks will be obtained from the selected microbes and enzyme collections. Untreated and physically/chemically pre-treated PE, PS, PP and PVC polymers and plastics will be employed in such isolation/ screening activities, and an integrated methodology, relying on advanced analytical methods (determining plastics physicochemical changes and breakdown products resulting from biological attack), and tailored enzymatic, microbiological and ecotoxicological methods, will be adopted for the characterization of actual industrial relevance of the obtained microbes and enzymes. Physical and chemical pretreatments improving biodegradability of target plastics will be identified and transferred on the pilot scale. The most promising microbial cultures and enzymes will be exploited in the development of pilot scale, slurry or solid-phase bioprocesses for the bioremediation and controlled depolymerization, respectively, of target pretreated plastics and in the set up of tailored bioaugmentation protocols for enhancing plastic waste biodegradation in marine water systems, composting and anaerobic digestor facilities. The processes developed will be assessed for their economical and environmental sustainability. Field scale validation of the most promising bioaugmentation protocols in a composting and a marine site and attempts to develop a plastic pollution reduction strategy for the Aegean Sea have been planned too


Wang M.,CAS Research Center for Eco Environmental Sciences | Markert B.,International Institute of Higher Education, Zittau | Chen W.,CAS Research Center for Eco Environmental Sciences | Peng C.,CAS Research Center for Eco Environmental Sciences | Ouyang Z.,CAS Research Center for Eco Environmental Sciences
Environmental Monitoring and Assessment | Year: 2012

In order to evaluate the current state of the environmental quality of soils in Beijing, we investigated contents of 14 metals in Beijing urban soils inside the 5th ring road by even grids sampling. Statistic analyses were conducted to identify possible heavy metal pollutants, as well as the effects of land uses on their accumulation. Our results revealed that the urban soils in Beijing were contaminated by Cd, Pb, Cu, and Zn. Land uses and urbanization ages affected the accumulation of the four heavy metals in soils significantly. Soils in industrial areas have the highest average Cu and Zn contents, while Pb contents in park areas and Cd in agricultural areas are the highest. The accumulations of Pb and Zn in urban soils increase significantly with sampling plots approaching the city center. And Pb, Cd, and Zn contents in soils in traffic areas also tend to increase in the city center. However, residential areas have the lowest contents of all the four heavy metals. © Springer Science+Business Media B.V. 2012.


Wang M.,CAS Research Center for Eco Environmental Sciences | Bai Y.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Chen W.,CAS Research Center for Eco Environmental Sciences | Markert B.,International Institute of Higher Education, Zittau | And 2 more authors.
Environmental Pollution | Year: 2012

Ecological risks of heavy metals in urban soils were evaluated using Beijing, China as an example. Cadmium, Cu, Zn, Pb, Cr and Ni contents of 233 surface soils sampled by 1 min latitude × 1 min longitude grid were used to identify their spatial distribution patterns and potential emission sources. Throughout the city, longer the duration of urbanization greater was the accumulations of heavy metals especially, Cd, Cu, Pb, and Zn. The soil Zn mainly came from the wears of vehicular tires. Point source emissions of heavy metals were few and far in the downwind south-east quadrant of Beijing. The calculated risk indices showed potential median eco-risks in the ancient central city. No potential high eco-risk due to soil-borne heavy metals was found. The potential medium eco-risk areas in Beijing would expand from the initial 24 to 110 km 2 if soil pH were to reduce by 0.5 units in anticipation. © 2011 Elsevier Ltd. All rights reserved.


Bianchin S.,Leibnitz Institute of Ecological and Regional Development | Richert E.,TU Bergakademie Freiberg | Heilmeier H.,TU Bergakademie Freiberg | Merta M.,International Institute of Higher Education, Zittau | Seidler C.,International Institute of Higher Education, Zittau
Landscape Online | Year: 2011

Within the framework of the project "Flood Prevention and Nature Conservation in the Weisseritz area" ("HochNatur"), a method including landscape metrics was developed and applied to assess and to compare different land use scenarios with regard to flood prevention and nature conservation. For the analysis, two sub-catchments strongly differing in land use within the Weisseritz catchment (Eastern Erzgebirge, Saxony, Germany) were selected. The first step of the evaluation procedure was a biotope assessment using three assessment criteria (naturalness, substitutability, rareness/endangerment). However, the biotope assessment did not yield any information about spatial distribution or the structural composition of the landscape. Therefore, landscape metrics were applied to analyse the structural and biotope type diversity at the landscape scale. Different landscape metrics (Shannon/Weaver diversity index, mean patch size index, Interdispersion/Juxtaposition index) and a weighting system were used to compare the different land use scenarios and the current state. The analysed catchment areas differ substantially in terms of their current state and potential measures regarding flood prevention and nature conservation depending on the location and distribution of biotope types. It was demonstrated that this method can be used for small catchment areas regardless of their land use for assessing, analysing and comparing different land use scenarios for a specific area. © 2011 IALE-D.


Wang M.,CAS Research Center for Eco Environmental Sciences | Chen W.,CAS Research Center for Eco Environmental Sciences | Markert B.,International Institute of Higher Education, Zittau
Agrochimica | Year: 2010

Fates of chlorimuron-ethyl were investigated in barren soils and farm soils for the purpose of better understanding of its persistence in fields and offering valid parameters for its eco- risk assessment. The degradation of chlorimuron-ethyl occurred mainly by chemical processes and fitted well to the first order kinetic models, with degradation rate constant k of 0.021 ±0.002 and 0.033±0.005, and half lives t1/2 of 32.7 and 21.4 in barren soils and farm soils, respectively, k negatively, while t 1/2 positively correlated with Koc and pH at a significant level of p<0.05. The persistence of chlorimuronethyl was caused by the adsorption to soil organic matter.


Grant
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: KBBE.2010.3.3-01 | Award Amount: 4.28M | Year: 2010

Enzymes catalyzing redox reactions (oxidoreductases) represent an environmentally-friendly alternative to harsh chemical reagents in industrial processes that include oxidative transformations for the production of chemicals and other value-added products with large markets in developed and emerging economies. Fungi and other micro-organisms provide the wider and more easily exploitable source for this type of enzymes. However, the penetration of microbial oxidoreductases in the above markets is still low despite the recent discovery of some of the most promising enzymes. Moreover, the use of enzymes as biocatalysts requires tuning their catalytic and operational properties, a type of genetic manipulation that is possible nowadays by the use of protein engineering tools. In the above scenario, the PEROXICATS project focuses first on the search for new peroxidases, one of the most interesting types of oxidoreductases due to their high redox-potential and unique peroxygenase activity recently described in some of them. The huge amount of genomic resources available nowadays, and to be generated during the course of the project, will be exploited in the search for new fungal peroxidase/peroxygenase genes. This will provide a collection of new enzymes to be evaluated in different oxidation reactions that could result in interesting products. On the other hand, some of the main issues presently limiting the industrial application of these enzymes will be addressed, namely their suicide inactivation by peroxide, low functional expression, and limited oxygen transfer potential. Moreover, the catalytic properties of the most interesting enzyme candidates will be modulated to adapt them to the industrial processes. In both cases, a combination of rational and non-rational design will be used, based on directed mutagenesis, and random mutagenesis together with high-throughput screening methods, respectively. In this way, a toolbox of novel and robust peroxidases/peroxygenases will be obtained with high industrial potential. The wide substrate specificity and catalytic plasticity of some peroxidases, which will be further improved within PEROXICATS, make them suitable, for example, to substitute harsh chemicals in the oxidation of recalcitrant compounds or other type of compounds for which a high-redox potential oxidant is required. Peroxygenases have also a great biotechnological potential since they can catalyze selective oxyfunctionalization reactions, among others, required in organic synthesis and difficult to achieve by conventional chemical tools. These characteristics make them of considerable interest in fine chemistry (e.g. substituting costly hydroxylation reactions currently used in the pharmaceutical sector) and bulk chemistry (e.g. for hydrocarbon oxyfunctionalization).

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