排序方式: 共有43条查询结果,搜索用时 31 毫秒
21.
Mihaela Marilena Stancu 《Environmental Forensics》2015,16(3):242-256
Rhodococcus erythropolis IBBPo5 (KM405337) and Lysinibacillus xylanilyticus IBBPo7 (KM405338) showed good tolerance to 5% (v/v) organic solvents (alkanes, aromatics). However, 5% (v/v) alkanes (i.e., cyclohexane, n-hexane, n-decane) were less toxic for R. erythropolis IBBPo5 and L. xylanilyticus IBBPo7 cells, compared with 5% (v/v) aromatics (i.e., toluene, o-xylene, ethylbenzene). The high organic solvent tolerance of these two Gram-positive bacteria could be due to the presence in their genome of some catabolic (alkB1, todM, xylM) and trehalose-6-phosphate synthase (otsA1) genes. R. erythropolis IBBPo5 possesses three catabolic genes (i.e., alkB1, todM, xylM), while L. xylanilyticus IBBPo7 possesses only one catabolic gene (i.e., alkB1). Numerous adaptations involved in organic solvents tolerance were depicted in R. erythropolis IBBPo5 and L. xylanilyticus IBBPo7 cells exposed to 5% (v/v) alkanes and aromatics (i.e., changes in the cell growth rate, membrane permeability, cell morphology, biosurfactant emulsification index, carotenoids profile, DNA fingerprinting). Therefore, microbiological, biochemical, and DNA fingerprinting studies of the bacteria isolated from polluted environments could provide valuable information that may complement or supplement other forensic investigations. 相似文献
22.
Ana-Maria Pană Liliana-Marinela Ştefan Geza Bandur Paula Sfîrloagă Vasile Gherman Mihaela Silion Marcel Popa Lucian-Mircea Rusnac 《Journal of Polymers and the Environment》2013,21(4):981-994
This paper presents the synthesis, thermal stability and biodegradability of new d-mannose glycopolymers. These glycopolymers have been obtained by free radical bulk copolymerization of d-mannose based glycomonomer, 1-O-(2′-hydroxy-3′-methacryloyloxypropyl)-2,3:5,6-di-O-isopropylidene-d-mannofuranose (Mm), and respectively d-mannose derived oligomer (Mo) with methyl methacrylate and respectively 2-hydroxypropyl methacrylate. The chemical structures of Mm and Mo have been confirmed via FTIR, 1H-NMR and HPLC–MS spectroscopy. The copolymerization process has been investigated using differential scanning calorimetry, which allowed calculating the activation energies by applying Kissinger–Akahira–Sunose method. The glycopolymers are thermally stable, fact assessed by TG analysis; their glass transition temperature exceeds 50 °C, so they are part of the glassy class of polymers. The biodegradability of these glycopolymers has been investigated in vitro, using pure cultures of Zymomonas mobilis and Trichoderma reesei. The glycopolymers lose up to 55 % weight in just 14 days of incubation as their surface and composition is altered by colonies of microorganisms that grow on/into them, fact demonstrated using SEM/EDX. 相似文献
23.
Mihaela Laura Vica Mirel Glevitzky Gabriela-Alina Dumitrel lia Monica Junie Maria Popa 《Journal of environmental science and health. Part. B》2013,48(3):176-181
Honey is used in food industry and medicine due to its nutritive, therapeutic and dietetic qualities. The microbiological characteristics of 10 unpasteurized honey samples of known origin, collected from Transylvania beekeepers (Romania) were determined. The antibacterial activity of these types of honey against Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Salmonella enteritidis, Salmonella anatum, Salmonella choleraesuis, Bacillus cereus, Bacillus subtilis subsp. spizizenii and Listeria monocytogenes strains was studied. The most sensitive to the antibacterial activity were the two staphylococus strains (the largest diameter of inhibition zone was 18 mm) and B. subtilis strains (13.5 mm). The strains of B. cereus, E. coli, L. monocytogenes and Salmonella spp. were found to present resistance to some of the honey samples. Manna, sunflower and polyfloral honeys presented high antibacterial activity while acacia and linden honeys had a lower activity in terms of the number of sensible strains. Statistical analysis shows that the type of strains and the type of honey have influence on the diameter of inhibition. 相似文献
24.
Mankovská B Godzik B Badea O Shparyk Y Moravcík P 《Environmental pollution (Barking, Essex : 1987)》2004,130(1):41-54
Concentrations of Al, B, Ca, Cu, Fe, K, Mg, Mn, N, Na, P, S and Zn in the foliage of white fir (Abies alba), Norway spruce (Picea abies) and common beech (Fagus sylvatica) from 25 sites of the Carpathian Mts. forests (Czech Republic, Poland, Romania, Slovakia and Ukraine) are discussed in a context of their limit values. S/N ratio was different from optimum in 90% of localities when compared with the European limit values. Likewise we found increase of Fe and Cu concentrations compared with their background levels in 100% of locations. Mn concentrations were increased in 76% of localities. Mn mobilization values indicate the disturbance of physiological balance leading to the change of the ratio with Fe. SEM-investigation of foliage waxes from 25 sites in the Carpathian Mts. showed, that there is a statistically significant difference in mean wax quality. Epistomatal waxes were damaged as indicated by increased development of net and amorphous waxes. The most damaged stomata in spruce needles were from Yablunitsa, Synevir and Brenna; in fir needles from Stoliky, and in beech leaves from Malá Fatra, Morské Oko and Beregomet. Spruce needles in the Carpathian Mts. had more damaged stomata than fir needles and beech leaves. Spruce seems to be the most sensitive tree species to environmental stresses including air pollution in forests of the Carpathian Mountains. Foliage surfaces of three forest tree species contained Al, Si, Ca, Fe, Mg, K, Cl, Mn, Na, Ni and Ti in all studied localities. Presence of nutrition elements (Ca, Fe, Mg, K and Mn) on foliage surface hinders opening and closing stomata and it is not physiologically usable for tree species. 相似文献
25.
Badea O Tanase M Georgeta J Anisoara L Peiov A Uhlirova H Pajtik J Wawrzoniak J Shparyk Y 《Environmental pollution (Barking, Essex : 1987)》2004,130(1):93-98
The results of forest health status assessments in the Carpathian Mountains from the monitoring networks developed by the European Union Scheme on the Protection of Forest Against Atmospheric Pollution (EU Scheme) and International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests), have led to a better understanding of the impact of air pollution and other stressors on forests at the regional scale. During the period 1997-2001, forests in the Carpathian Mountains were severely affected by air pollution and natural stresses with 29.7-34.9% of the trees included in defoliation classes 2-4. The broadleaves were slightly healthier than the conifers, and European beech (Fagus sylvatica) was the least affected species. Norway spruce (Picea abies) has poor health status, with 42.9-46.6% of the trees damaged (2-4% defoliation classes). Silver fir (Abies alba) damage was also high, with 46.0-50.9% in defoliation classes 2-4. Pines (primarily Pinus sylvestris) were the least affected of the conifers, with 24.9-33.8% in defoliation classes 2-4. The results from the transnational networks (16 x 16 km) show that the Carpathian forests are slightly more damaged than the average for the entire Europe. The correlative studies performed in individual European countries show the relationships between air pollution stressors with trends in defoliation and a possible effect of natural stresses at each site. More specific, effects of tree age, drought, ozone and acid deposition critical level exceedances were demonstrated to affect crown condition. 相似文献
26.
One potential drawback of compost-based passive bioreactors, which is a promising biotechnology for acid mine drainage (AMD)
treatment, is the transport of dissolved organic matter (DOM)-metal complexes in surface waters. To address this problem, the objective
of this study was to assess the maximum capacity of organic substrates to release soluble DOM-metal complexes in treated water.
The reactivities of DOM in maple wood chips and sawdust, composted poultry manure, and leaf compost were quantified toward
Cd2+, Ni2+, Fe2+, and Cu2+ using fluorescence quenching. The DOM showed the highest reactivity toward Fe, but a limited number
of available sites for sorption, whereas DOM-Cd complexes exhibited the lowest fluorescence quenching. Overall, the DOM from a
mixture of wastes formed higher concentrations of DOM-metal complexes relative to sole substrates. Among DOM-metal complexes,
the concentrations of DOM-Ni complexes were the highest. After reaching steady-state, low concentrations of DOM-metal complexes
were released in treated water, which is in agreement with theoretical predictions based on geochemical modeling. Therefore, in addition
to physicochemical characterization, fluorescence quenching technique is recommended for the substrate selection of bioreactors. 相似文献
27.
Săcărescu Liviu Chibac-Scutaru Andreea-Laura Roman Gheorghe Săcărescu Gabriela Simionescu Mihaela 《Environmental Chemistry Letters》2023,21(1):561-596
Environmental Chemistry Letters - Pollution by toxic metals is a worldwide health issue, yet analytical methods to monitor selectively metal ions in complex media are limited. Fluorescence sensing... 相似文献
28.
Gitea Manuel Alexandru Gitea Daniela Tit Delia Mirela Purza Lavinia Samuel Alina Dora Bungău Simona Badea Gabriela Elena Aleya Lotfi 《Environmental science and pollution research international》2019,26(10):9908-9915
Environmental Science and Pollution Research - The authors analyzed certain species and varieties of fruit tree in which applied crop technology is used and also undergoes the effects of climate... 相似文献
29.
Gabriela Geanina Vasile Dana Elena Popa Mihaela Buleandră Iulia Gabriela David 《Environmental monitoring and assessment》2018,190(10):609
The evaluation of the cadmium and lead mobile forms from environmental solid samples provides information about their mobility and bioavailability. In the present study, the Cd and Pb mobile fractions were obtained by two modified extraction methods applied to industrial and acidic pH soils or to polluted sediments. In order to highlight that the extraction procedure does not significantly influence the quantitative atomic absorption spectrometric determination of cadmium and lead, the robustness of the extraction methods was evaluated and proven applying a Youden and Steiner factorial design. Within this experimental design, the shaking rate, the shaking time, and the solid/liquid extraction ratio were modified. The measurement uncertainty of the whole analytical procedure was assessed, the contribution of the factors involved in the extraction process being insignificant compared to the other uncertainty sources. The importance of the study is related to the fact that it proves the applicability in the routine laboratory practice of the modified extraction methods by increasing the extraction ratio following thorough optimization and robustness studies. 相似文献
30.
Bidar G Pruvot C Garçon G Verdin A Shirali P Douay F 《Environmental science and pollution research international》2009,16(1):42-53
Background, aim, and scope The reclamation of nonferrous metal-polluted soil by phytoremediation requires an overall and permanent plant cover. To select
the most suitable plant species, it is necessary to study metal effects on plants over the time, thereby checking that metals
remain stored in root systems and not transferred to aerial parts. In this purpose, the seasonal and annual variations of
metal bioaccumulation, transfer, and phytotoxicity in Trifolium repens and Lolium perenne grown in a Cd-, Pb-, and Zn-contaminated soil were also studied.
Materials and methods The experimental site was located near a closed smelter. In spring 2004, two areas were sown with T. repens and L. perenne, respectively. Thereafter, the samplings of plant roots and shoots and surrounding soils were realized in autumn 2004 and
spring and autumn 2005. The soil agronomic characteristics, the Cd, Pb, and Zn concentrations in the surrounded soils and
plant organs, as well as the oxidative alterations (superoxide dismutase [SOD], malondialdehyde [MDA], and 8-hydroxy-2′-deoxyguanosine
[8-OHdG]) in plant organs were carried out.
Results Whatever the sampling period, metal concentrations in soils and plants were higher than background values. Contrary to the
soils, the fluctuations of metal concentrations were observed in plant organs over the time. Bioaccumulation and transfer
factors confirmed that metals were preferentially accumulated in the roots as follows: Cd>Zn>Pb, and their transfer to shoots
was limited. Foliar metal deposition was also observed. The results showed that there were seasonal and annual variations
of metal accumulation in the two studied plant species. These variations differed according to the organs and followed nearly
the same pattern for the two species. Oxidative alterations were observed in plant organs with regard to SOD antioxidant activities,
MDA, and 8-OHdG concentrations. These alterations vary according to the temporal variations of metal concentrations.
Discussion Metal concentrations in surrounded soils and plant organs showed the effective contamination by industrial dust emissions.
Metals absorbed by plants were mainly stored in the roots. With regard to this storage, the plants seemed to limit the metal
transfer to their aerial parts over the time, thereby indicating their availability for metal phytostabilization. Aerial deposition
was another source of plant exposure to nonferrous metals. Despite the occurrence of metal-induced oxidative alterations in
plant organs, both plant species seemed to tolerate a high metal concentration in soils.
Conclusions Taken together, these results indicated that T. repens and L. perenne were able to form a plant cover on highly Cd-, Pb-, and Zn-polluted soils, to limit the metal transfer to their aerial parts
and were relatively metal-tolerant. All these characteristics made them suitable for phytostabilization on metal-contaminated
soils. These findings also highlighted the necessity to take into account seasonal and annual variations for a future phytomanagement.
Recommendations and perspectives In this work, the behavior of plant species grown in metal-polluted soil has been studied during 2 years. Obviously, this
time is too short to ensure that metals remain accumulated in the root system and few are transferred in aerial parts over
the time. It is why regular monitoring should be achieved during more than a decade after the settlement of the plant cover.
This work will be completed by the study of the T. repens and L. perenne effects on mobility of metals in order to evaluate the quantities of pollutants which could be absorbed by the biota and
transferred to groundwater. Bioaccessibility tests could be also realized on polluted soils in order to evaluate the phytostabilization
impacts on the exposition risks for humans. 相似文献