scholarly journals Modification of the Bacterial Cell Wall—Is the Bioavailability Important in Creosote Biodegradation?

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 147
Author(s):  
Wojciech Smułek ◽  
Amanda Pacholak ◽  
Ewa Kaczorek
Keyword(s):  
Current Knowledge ◽  
Complex Mixture ◽  
Wood Preservative ◽  
Surface Modifications ◽  
Polycyclic Aromatic Compounds ◽  
Transferase Activity ◽  
Glutathione S Transferase ◽  
Polycyclic Aromatic ◽  
Total Membrane

Creosote oil, widely used as a wood preservative, is a complex mixture of different polycyclic aromatic compounds. The soil contamination result in the presence of a specific microcosm. The presented study focuses on the most active strains involved in bioremediation of long-term creosote-contaminated soil. In three soil samples from different boreholes, two Sphingomonas maltophilia (S. maltophilia) and one Paenibacillus ulginis (P. ulginis) strain were isolated. The conducted experiments showed the differences and similarities between the bacteria strains capable of degrading creosote from the same contaminated area. Both S. maltophilia strains exhibit higher biodegradation efficiency (over 50% after 28 days) and greater increase in glutathione S-transferase activity than P. ulginis ODW 5.9. However, S. maltophilia ODW 3.7 and P. ulginis ODW 5.9 were different from the third of the tested strains. The growth of the former two on creosote resulted in an increase in cell adhesion to Congo red and in the total membrane permeability. Nevertheless, all three strains have shown a decrease in the permeability of the inner cell membrane. That suggests the complex relationship between the cell surface modifications and bioavailability of the creosote to microorganisms. The conducted research allowed us to broaden the current knowledge about the creosote bioremediation and the properties of microorganisms involved in the process.

scholarly journals Functional Diversification of Fungal Glutathione Transferases from the Ure2p Class

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Anne Thuillier ◽  
Andrew A. Ngadin ◽  
Cécile Thion ◽  
Patrick Billard ◽  
Jean-Pierre Jacquot ◽  
...  
Keyword(s):  
Extended Family ◽  
Polycyclic Aromatic Compounds ◽  
Glutathione Transferases ◽  
Transcriptional Level ◽  
Environmental Constraints ◽  
Glutathione S Transferase ◽  
Functional Diversification ◽  
Catalytic Activities ◽  
Polycyclic Aromatic ◽  
And Function

The glutathione-S-transferase (GST) proteins represent an extended family involved in detoxification processes. They are divided into various classes with high diversity in various organisms. The Ure2p class is especially expanded in saprophytic fungi compared to other fungi. This class is subdivided into two subclasses named Ure2pA and Ure2pB, which have rapidly diversified among fungal phyla. We have focused our analysis on Basidiomycetes and used Phanerochaete chrysosporium as a model to correlate the sequence diversity with the functional diversity of these glutathione transferases. The results show that among the nine isoforms found in P. chrysosporium, two belonging to Ure2pA subclass are exclusively expressed at the transcriptional level in presence of polycyclic aromatic compounds. Moreover, we have highlighted differential catalytic activities and substrate specificities between Ure2pA and Ure2pB isoforms. This diversity of sequence and function suggests that fungal Ure2p sequences have evolved rapidly in response to environmental constraints.

scholarly journals Emissions databases for polycyclic aromatic compounds in the Canadian Athabasca Oil Sands Region – development using current knowledge and evaluation with passive sampling and air dispersion modelling data

2017 ◽  
Author(s):  
Xin Qiu ◽  
Irene Cheng ◽  
Fuquan Yang ◽  
Erin Horb ◽  
Leiming Zhang ◽  
...  
Keyword(s):  
Aromatic Compounds ◽  
Oil Sands ◽  
Current Knowledge ◽  
Monitoring Network ◽  
Polycyclic Aromatic Compounds ◽  
Athabasca Oil Sands ◽  
Voc Emissions ◽  
Fire Emissions ◽  
Athabasca Oil Sands Region ◽  
Polycyclic Aromatic

Abstract. Two speciated and spatially-resolved emissions databases for polycyclic aromatic compounds (PAC) in the Athabasca oil sands region (AOSR) were developed. The first database was derived from volatile organic compound (VOC) emissions data provided by the Cumulative Environmental Management Association (CEMA) and the second database was derived from additional data collected within the Joint Canada-Alberta Oil Sands Monitoring (JOSM) program. CALPUFF modelling results for atmospheric polycyclic aromatic hydrocarbons (PAH), alkylated PAH, and dibenzothiophenes (DBT), obtained using each of the emissions databases, are presented and compared with measurements from a passive air monitoring network. The JOSM-derived emissions resulted in better model-measurement agreement in the total PAH concentrations and for most PAH species concentrations, compared to results using CEMA-derived emissions. At local sites near oil sands mines, the percent error of the model compared to observations decreased from 30 % using the CEMA-derived emissions to 17 % using the JOSM-derived emissions. The improvement at local sites was likely attributed to the inclusion of updated tailings pond emissions estimated from JOSM activities. In either the CEMA-derived or JOSM-derived emissions scenario, the model underestimated PAH concentrations by a factor of 3 at remote locations. Potential reasons for the disagreement include forest fire emissions, re-emissions of previously deposited PAHs, and long-range transport not considered in the model. Alkylated PAH and DBT concentrations were also significantly underestimated. The CALPUFF model is expected to predict higher concentrations because of the limited chemistry and deposition modelling. Thus the model underestimation of PACs is likely due to gaps in the emissions database for these compounds and uncertainties in the methodology for estimating the emissions. Future work is required that focuses on improving the PAC emission estimation and speciation methodologies and reducing the uncertainties in VOC emissions which are subsequently used in PAC emissions estimation.

scholarly journals Emissions databases for polycyclic aromatic compounds in the Canadian Athabasca oil sands region – development using current knowledge and evaluation with passive sampling and air dispersion modelling data

2018 ◽  
Vol 18 (5) ◽  
pp. 3457-3467 ◽  
Author(s):  
Xin Qiu ◽  
Irene Cheng ◽  
Fuquan Yang ◽  
Erin Horb ◽  
Leiming Zhang ◽  
...  
Keyword(s):  
Aromatic Compounds ◽  
Oil Sands ◽  
Current Knowledge ◽  
Monitoring Network ◽  
Polycyclic Aromatic Compounds ◽  
Athabasca Oil Sands ◽  
Voc Emissions ◽  
Fire Emissions ◽  
Athabasca Oil Sands Region ◽  
Polycyclic Aromatic

Abstract. Two speciated and spatially resolved emissions databases for polycyclic aromatic compounds (PACs) in the Athabasca oil sands region (AOSR) were developed. The first database was derived from volatile organic compound (VOC) emissions data provided by the Cumulative Environmental Management Association (CEMA) and the second database was derived from additional data collected within the Joint Canada–Alberta Oil Sands Monitoring (JOSM) program. CALPUFF modelling results for atmospheric polycyclic aromatic hydrocarbons (PAHs), alkylated PAHs, and dibenzothiophenes (DBTs), obtained using each of the emissions databases, are presented and compared with measurements from a passive air monitoring network. The JOSM-derived emissions resulted in better model–measurement agreement in the total PAH concentrations and for most PAH species concentrations compared to results using CEMA-derived emissions. At local sites near oil sands mines, the percent error of the model compared to observations decreased from 30 % using the CEMA-derived emissions to 17 % using the JOSM-derived emissions. The improvement at local sites was likely attributed to the inclusion of updated tailings pond emissions estimated from JOSM activities. In either the CEMA-derived or JOSM-derived emissions scenario, the model underestimated PAH concentrations by a factor of 3 at remote locations. Potential reasons for the disagreement include forest fire emissions, re-emissions of previously deposited PAHs, and long-range transport not considered in the model. Alkylated PAH and DBT concentrations were also significantly underestimated. The CALPUFF model is expected to predict higher concentrations because of the limited chemistry and deposition modelling. Thus the model underestimation of PACs is likely due to gaps in the emissions database for these compounds and uncertainties in the methodology for estimating the emissions. Future work is required that focuses on improving the PAC emissions estimation and speciation methodologies and reducing the uncertainties in VOC emissions which are subsequently used in PAC emissions estimation.

scholarly journals Impact of mobile stroke units

2021 ◽  
pp. jnnp-2020-324005
Author(s):  
Klaus Fassbender ◽  
Fatma Merzou ◽  
Martin Lesmeister ◽  
Silke Walter ◽  
Iris Quasar Grunwald ◽  
...  
Keyword(s):  
Cost Efficiency ◽  
Current Knowledge ◽  
Vascular Imaging ◽  
Vessel Occlusion ◽  
Stroke Units ◽  
Stroke Treatment ◽  
Stroke Research ◽  
Mobile Stroke Unit ◽  
Novel Strategy

Since its first introduction in clinical practice in 2008, the concept of mobile stroke unit enabling prehospital stroke treatment has rapidly expanded worldwide. This review summarises current knowledge in this young field of stroke research, discussing topics such as benefits in reduction of delay before treatment, vascular imaging-based triage of patients with large-vessel occlusion in the field, differential blood pressure management or prehospital antagonisation of anticoagulants. However, before mobile stroke units can become routine, several questions remain to be answered. Current research, therefore, focuses on safety, long-term medical benefit, best setting and cost-efficiency as crucial determinants for the sustainability of this novel strategy of acute stroke management.

Sign in / Sign up

Export Citation Format

Share Document