Publications by authors named "Baiyu Zhang"

71 Publications

A cross-comparison of biosurfactants as marine oil spill dispersants: Governing factors, synergetic effects and fates.

J Hazard Mater 2021 08 21;416:126122. Epub 2021 May 21.

The Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL, Canada. Electronic address:

Biosurfactant-based dispersants (BBDs) may be more effective, cost-efficient and environmentally friendly than dispersants currently used for oil spill response. An improved understanding of BBD performance is needed to advance their development and commercial use. In this study, the ability of four BBDs, i.e. sufactins, trehalose lipids, rhamnolipids and exmulsins, alone and as various combinations to disperse Arabian light crude oil and weathered Alaska North Slope crude oil was compared to a widely used commercial oil dispersant (Corexit 9500A). Surfactin and trehalose lipids, which have balanced surface activity/emulsification ability, showed dispersion efficacy comparable to Corexit 9500A. Rhamnolipids (primarily a surface-active agent) and exmulsins (primarily an emulsifier) when used alone had significantly lower efficacy. However, blends of these surfactants had excellent dispersion performance because of synergistic effects. Balanced surface activity and emulsification ability may be key to formulate effective BBDs. Of the BBDs evaluated, surfactins with an effective dispersant-to-oil ratio as low as 1:62.3 and trehalose lipids with high oil affinity, biodegradation rate, and low toxicity characteristics show the most promise for commercial development.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126122DOI Listing
August 2021

Functional modification of HHCB: Strategy for obtaining environmentally friendly derivatives.

J Hazard Mater 2021 08 25;416:126116. Epub 2021 May 25.

Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University, St. John's, Newfoundland, Canada A1B 3X5. Electronic address:

Galaxolide (HHCB), one of the most widely used synthetic musks in personal care products (PCPs), has been recognized as an emerging contaminant with potential human health concerns. To overcome such adverse effects, a systematic molecular design, screening and performance evaluation approach was developed to generate functionally improved and environmentally friendly HHCB derivatives. Among the 90 designed HHCB derivatives, 15 were screened with improved functional properties (i.e., odor stability and intensity) and less environmental impacts (i.e., lower bio-toxicity, bio-accumulation ability, and mobility) using 3D-QSAR models and density functional theory methods. Their human health risks were then assessed by toxicokinetic analysis, which narrowed the candidates to four. Derivative 7, the designed molecule with the least dermal adsorption potential, was evaluated for its interaction with other PCPs additives (i.e., anti-photosensitivity materials and moisturizer) and such impacts on human health risks using molecular docking and molecular dynamic simulation. The environmental fate of Derivative 7 after transformation (i.e., photodegradation, biotransformation, and chlorination) was also discussed. Biotransformation and chlorination were recognized as optimum options for Derivative 7 mitigation. This study provided the theoretical basis for the design of functionally improved and environmentally friendly HHCB alternatives and advanced the understanding of their environmental behaviors and health risks.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126116DOI Listing
August 2021

The application of the "omental wrapping" technique with autologous onlay flap/graft ureteroplasty for the management of long ureteral strictures.

Transl Androl Urol 2021 Jul;10(7):2871-2878

Department of Urology, Peking University First Hospital, Institute of Urology, Peking University, National Urological Cancer Center, Beijing, China.

Background: To present our experience with the "omental wrapping" technique in laparoscopic and robotic ureteroplasty using onlay flaps or grafts for the management of long proximal or middle ureteral strictures.

Methods: This is a retrospective review of 25 patients with long proximal or middle ureteral strictures who underwent laparoscopic and robotic onlay flaps or grafts ureteroplasty using an omental flap to reinforce an anastomosis site between August 2018 and November 2019. Perioperative and follow-up data were collected.

Results: Sixteen laparoscopic procedures and nine robotic procedures were performed successfully. Sixteen patients underwent ureteroplasty with lingual mucosal graft (LMG), and nine patients with appendiceal onlay flap (AOF). The median stricture length was 4 cm (range, 2-6 cm). The mean operative time (OT) was 220.5±50.6 min, the estimated blood loss (EBL) was 66.0±38.9 mL, and the length of hospital stay (LHS) was 8.0±3.6 days. In the LMG group, four patients had tongue numbing and one had an oral ulcer, which relieved itself gradually without intervention. Two patients in the LMG group and four patients in the AOF group experienced urinary tract infection, and all responded well to antibiotic treatment. There were no complications attributed to "omental wrapping". The mean follow-up was 16.3±4.8 months. According to the standards regarding improvement in clinical symptoms, relief of obstruction radiologically and a stable estimate glomerular filtration rate, our surgical success rate was 100%.

Conclusions: The "omental wrapping" technique in laparoscopic and robotic onlay flaps or grafts ureteroplasty for long proximal or middle ureteral strictures is an efficient, safe, reproducible and simple technique.
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http://dx.doi.org/10.21037/tau-21-305DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8350257PMC
July 2021

An improved calibration and uncertainty analysis approach using a multicriteria sequential algorithm for hydrological modeling.

Sci Rep 2021 Aug 20;11(1):16954. Epub 2021 Aug 20.

Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL, A1B 3X5, Canada.

Hydrological models are widely used as simplified, conceptual, mathematical representatives for water resource management. The performance of hydrological modeling is usually challenged by model calibration and uncertainty analysis during modeling exercises. In this study, a multicriteria sequential calibration and uncertainty analysis (MS-CUA) method was proposed to improve the efficiency and performance of hydrological modeling with high reliability. To evaluate the performance and feasibility of the proposed method, two case studies were conducted in comparison with two other methods, sequential uncertainty fitting algorithm (SUFI-2) and generalized likelihood uncertainty estimation (GLUE). The results indicated that the MS-CUA method could quickly locate the highest posterior density regions to improve computational efficiency. The developed method also provided better-calibrated results (e.g., the higher NSE value of 0.91, 0.97, and 0.74) and more balanced uncertainty analysis results (e.g., the largest P/R ratio values of 1.23, 2.15, and 1.00) comparing with other traditional methods for both case studies.
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http://dx.doi.org/10.1038/s41598-021-96250-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8379175PMC
August 2021

Exploring the use of alginate hydrogel coating as a new initiative for emergent shoreline oiling prevention.

Sci Total Environ 2021 Jul 22;797:149234. Epub 2021 Jul 22.

Fisheries and Oceans Canada, Ecosystem Science, Ottawa, ON K1A 0E6, Canada.

Marine oil spills are often reported as a result of activities associated with oil exploration, production and transportation. The spilled oil may reach the shoreline, and then the stranded oil can persist for a long time, exerting many negative effects on coastal ecosystems. Conventional shoreline cleanup methods cannot effectively remove the oil residues from affected areas and are very expensive. Therefore, the use of alginate hydrogel coatings was proposed as a new initiative for emergent shoreline oiling prevention. The alginate hydrogel-coated gravels showed high surface roughness, as well as remarkable water wetting and low-oil-adhesion properties. There was a low oil adhesion on the coated gravels in the continuous test with oil/water emulsion flow, indicating the excellent oil-repellent properties of the coated substrate. The results of batch oil-repellent tests showed that independent of the kind or weathering degree of the oil used, oil can be easily washed out from the coated gravels. The coated gravels had good environmental stability and the slightly partial de-crosslinking of alginate structure would not reduce the oil repellence performance. Moreover, the performance of the alginate hydrogel-coated gravel was further proved with a laboratory shoreline tank simulator, in which more stranded oil floated to the water surface and less oil remained on gravels and entered into subsurface. This proposed oiling prevention method can be used not only for shorelines but also for coastal piers, seaports, and solid manmade shorelines. The coating material is derived from the biomass in the ocean and can be degraded under natural conditions. This study may provide a unique direction for the future development of green oil spill control strategy.
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http://dx.doi.org/10.1016/j.scitotenv.2021.149234DOI Listing
July 2021

Investigation into the impact of aged microplastics on oil behavior in shoreline environments.

J Hazard Mater 2021 Jul 21;421:126711. Epub 2021 Jul 21.

Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada.

Understanding the interactions between oil and other particles in shoreline can help determine the environmental risk and cleanup strategy after oil spill. Nevertheless, far less has been known regarding the impact of aged MPs on oil behavior in the shoreline environment. In this study, the aging course of polyethylene (PE) in shaking seawater and ultraviolet (UV) radiation conditions was investigated. The seawater aging mainly affected the physical properties of MPs, increasing its surface pores and hydrophilicity. UV aging significantly affected both the physical and chemical properties of MPs, which increased its hydrophilicity and crystallinity, decreased its mean particle size and introduced oxygen-containing functional groups onto MPs. The two-dimensional correlation spectroscopy (2D COS) analysis confirmed the evolution of oxygen-containing functional groups from C-O to CO. The effects of aged MPs on oil behavior in water-sand system were further explored. The oil remaining percentages were non-linearly changed with the increasing aging degree of MPs. The particle size of the aqueous phase after washing was inversely related to the oil remaining percentage. Further FTIR analysis revealed that C-O and C-H functional groups played an important role in the process of oil adsorbed on MPs.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126711DOI Listing
July 2021

A critical review on the environmental application of lipopeptide micelles.

Bioresour Technol 2021 Nov 17;339:125602. Epub 2021 Jul 17.

Department of Civil Engineering, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL, Canada.

The importance of lipopeptide micelles in environmental applications has been highlighted. These vessels exhibit various sizes, shapes, and surface properties under different environmental conditions. An in-depth understanding of the tunable assembling behavior of biosurfactant micelles is of great importance for their applications. However, a systematic review of such behaviors with assorted micro/nano micellar structures under given environmental conditions, particularly under low temperature and high salinity, remains untapped. Such impacts on their environmental applications have yet to be summarized. This review tried to fill the knowledge gaps by providing a comprehensive summary of the recent knowledge advancement in genetically regulated lipopeptides production, micelles associated decontamination mechanisms in low temperature and high salinity environments, and up-to-date environmental applications. This work is expected to deliver valuable insights to guide lipopeptide design and discovery. The mechanisms concluded in this study could inspire the forthcoming research efforts in the advanced environmental application of lipopeptide micelles.
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http://dx.doi.org/10.1016/j.biortech.2021.125602DOI Listing
November 2021

Antibiotics in mariculture organisms of different growth stages: Tissue-specific bioaccumulation and influencing factors.

Environ Pollut 2021 Jul 7;288:117715. Epub 2021 Jul 7.

Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China. Electronic address:

Maricultured organisms are chronically exposed to water containing antibiotics but the bioaccumulative behavior of antibiotics in exposed organisms at different growth stages has received little attention. Here, we investigated the concentrations and tissue-specific bioaccumulation characteristics of 19 antibiotics during three growth stages (youth stage, growth stage, and adult stage) of various organisms (Scophthalmus maximus, Penaeus vannamei, Penaeus japonicus, and Apostichopus japonicus) cultivated in typical marine aquaculture regions, and explored the factors that could affect the bioaccumulation of antibiotics. Tetracyclines (TCs) and fluoroquinolones (FQs) were the dominant antibiotics in all organisms, and the total concentrations of the target antibiotics in fish (S. maximus) were significantly higher than those in shrimp (P. vannamei and P. japonicus) and sea cucumber (A. japonicus) (p < 0.01). The bioaccumulation capacity of a class of statistically significant antibiotics in most samples was strongest during the youth stage and weakest during the adult stage. The antibiotics exhibited higher bioaccumulation capacity in lipid-rich tissues (fish liver and shrimp head) or respiratory organs (fish gill) than muscle. Our results also reveal significant metabolic transformation of enrofloxacin in fish. Different from previous studies, the logarithm bioaccumulation factor (log BAF) was positively correlated with log D in low-biotransformation tissues (fish gill and muscle) rather than lipid-rich tissues (fish liver). Based on the calculated hazard quotients (HQ), doxycycline in fish muscle may pose a distinct risk to human health, which deserves special attention. Overall, these results provide insight into the bioaccumulation patterns of antibiotics during different growth stages and tissues of maricultured organisms.
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http://dx.doi.org/10.1016/j.envpol.2021.117715DOI Listing
July 2021

Formation of oil-particle aggregates: Impacts of mixing energy and duration.

Sci Total Environ 2021 Nov 6;795:148781. Epub 2021 Jul 6.

Department of Fisheries and Oceans, Dartmouth, NS B2Y 4A2, Canada.

Spilled oil slicks are likely to break into droplets offshore due to wave energy. The fate and transport of such droplets are affected by suspended particles in local marine environment, through forming oil particle aggregates (OPAs). OPA formation is affected by various factors, including the mixing energy and duration. To evaluate these two factors, lab experiments of OPA formation were conducted using kaolinite at two hydrophobicities in baffled flasks, as represented by the contact angle of 28.8° and 37.7° (original and modified kaolinite). Two mixing energies (energy dissipation rates of 0.05 and 0.5 W/kg) and four durations (10 min, 30 min, 3 h, and 24 h) were considered. Penetration to the oil droplets was observed at 3-5 μm and 5-7 μm for the original and modified kaolinite by confocal microscopy, respectively. At lower mixing energy, volume median diameter d50 of oil droplets increased from 45 μm to 60 μm after 24 h mixing by original kaolinite; for modified kaolinite, d50 decreased from 40 μm to 25 μm after 24 h mixing. The trapped oil amount in negatively buoyant OPAs decreased from 35% (3 h mixing) to 17% (24 h mixing) by original kaolinite; and from 18% to 12% after 24 h mixing by modified kaolinite. Results indicated that the negatively buoyant OPAs formed with original kaolinite at low mixing energy reaggregated after 24 h. At higher mixing energy, d50 decreased from 45 μm to 17 μm after 24 h mixing for both kaolinites. And the trapped oil amount in negatively buoyant OPAs increased to 72% and 49% after 24 h mixing for original and modified kaolinite, respectively. At higher mixing energy, the OPAs formed within 10 min and reached equilibrium at 3 h by original kaolinite. For modified kaolinite, the OPAs continued to form through 24 h.
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http://dx.doi.org/10.1016/j.scitotenv.2021.148781DOI Listing
November 2021

Access-dispersion-recovery strategy for enhanced mitigation of heavy crude oil pollution using magnetic nanoparticles decorated bacteria.

Bioresour Technol 2021 Oct 12;337:125404. Epub 2021 Jun 12.

The Northern Region Persistent Organic Pollution (NRPOP) Control Laboratory, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL A1B 3X5, Canada.

Heavy crude oil (HCO) pollution has gained global attention, but traditional bioremediating practices demonstrate limited effectiveness. This study developed magnetic nanoparticles decorated bacteria (MNPB) using an oil-degrading and biosurfactant-producing Rhodococcus erythropolis species and identified a novel access-dispersion-recovery strategy for enhanced HCO pollution mitigation. The strategy entails (1) magnetic navigation of the MNPB towards HCO layer, (2) enhanced oil dispersion and formation of suspended oil-bacteria aggregates, and (3) magnetic recovery of these aggregates. The UV-spectrophotometer analysis showed that this strategy can enable up to 62% removal of HCO. The GC-MS analysis demonstrated that the MNPB enhanced the degradation of low-molecular-weight aromatics comparing with the pure bacteria, and the recovery process further removed oil-bacteria aggregates and entrained high-molecular-weight aromatics. The feasibility of using MNPB to mitigate HCO pollution could shed light on the emerging bioremediation applications.
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http://dx.doi.org/10.1016/j.biortech.2021.125404DOI Listing
October 2021

A data-driven binary-classification framework for oil fingerprinting analysis.

Environ Res 2021 Jun 8;201:111454. Epub 2021 Jun 8.

Northern Region Persistent Organic Pollutant Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL, A1B 3X5, Canada.

A marine oil spill is one of the most challenging environmental issues, resulting in severe long-term impacts on ecosystems and human society. Oil dispersants are widely applied as a treating agent in oil spill response operations. The usage of dispersants significantly changes the behaviors of dispersed oil and consequently challenges the oil fingerprinting analysis. In this study, machine learning was first introduced to analyze oil fingerprinting by developing a data-driven binary classification framework. The modeling integrated dimensionality reduction algorithms (e.g., principal component analysis, PCA) to distinguish. Five groups of biomarkers, including terpanes, steranes, triaromatic steranes (TA-steranes), monoaromatic steranes (MA-steranes), and diamantanes, were selected. Different feature spaces were created from the diagnostic index of biomarkers, and six ML algorithms were applied for comparative analysis and optimizing the modeling process, including k-nearest neighbor (KNN), support vector classifier (SVC), random forest classifier (RFC), decision tree classifier (DTC), logistic regression classifier (LRC), and ensemble vote classifier (EVC). Hyperparameter optimization and cross-validation through GridSearchCV were applied to prevent overfitting and increase the model accuracy. Model performance was evaluated by model score and F-score through confusion matrices. The results indicated that the RFC algorithm from the diamantanes dataset performed the best. It delivered the highest F-score (0.871) versus the lowest F-score (0.792) from the EVC algorithm from the TA-steranes dataset by PCA with a variance of 95%. Therefore, diamantanes were recommended as the most suitable biomarker for distinguishing WCO and CDO to aid oil fingerprinting under the conditions in this study. The results proved the proposed method as a potential analysis tool for oil spill source identification through ML-aided oil fingerprinting. The study also showed the value of ML methods in oil spill response research and practice.
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http://dx.doi.org/10.1016/j.envres.2021.111454DOI Listing
June 2021

3D-QSAR-aided toxicity assessment of synthetic musks and their transformation by-products.

Environ Sci Pollut Res Int 2021 Jun 5. Epub 2021 Jun 5.

Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Civil Engineering, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL, A1B 3X5, Canada.

Synthetic musks (SMs) are fragrance additives widely used in personal care products. SMs and their transformation by-products may reach the environment even after wastewater treatment, resulting in ecological and health concerns. The identification and toxicity assessment of SM by-products generated from different chemical and biological treatment processes have been rarely studied. This study established a 3D-QSAR model based on SMs' molecular structures (independent variable) and their lethal concentration (LC) of mysid (dependent variable). The developed model was further used to predict the LC of SMs transformation by-products. Fifty-eight by-products of six common SMs (i.e., galaxolide (HHCB), tonalide (AHTN), phantolide (PHAN), traseolide (TRASE), celestolide (ADBI), and musk ketone (MK)) generated from biodegradation, photodegradation, advanced oxidation, and chlorination were identified through literature review and lab experiment as the model inputs. Predicted LC results indicated that the toxicity of 40% chlorination by-products is higher than their precursors. Biodegradation is an effective method to treat AHTN. The advanced oxidation may be the best way to treat HHCB. This is the first study on biotoxicity of SM transformation by-products predicted by the 3D-QSAR model. The research outputs helped to provide valuable reference data and guidance to improve management of SMs and other emerging contaminants.
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http://dx.doi.org/10.1007/s11356-021-14672-1DOI Listing
June 2021

Oral absorption mechanism of the polysaccharides from Gastrodia elata Blume base on fluorescence labeling.

Food Res Int 2021 06 24;144:110342. Epub 2021 Mar 24.

Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, PR China. Electronic address:

The mechanisms of action of polysaccharides in vivo have been widely elucidated. However, the systematic research of its absorption and transport mechanisms remains unclear. Herein, we extracted a polysaccharide fraction (GEP) from Gastrodia elata by water extraction and alcohol precipitation and aimed to reveal its oral absorption processes through animal models and Caco-2 cells monolayer models. Our research data showed that GEP-Cy5.5 could be absorbed through the small intestine and the main absorption intestinal segment was the ileum (the absorption rate constant [Ka]: (3.64 ± 0.70) × 10 cm/s; the effective apparent permeability [Papp value]: (4.88 ± 1.02) × 10 cm/s). The ligated intestinal loops also revealed that GEP-Cy5.5 could pass through the villi of the small intestine and the mucosal barrier into the submucosa. Furthermore, GEP-Cy5.5 was readily absorbed into the blood through the gastrointestinal tract, then distributed in the liver and the kidney. The Papp value of in vitro transport study was (1.29 ± 0.08) × 10 cm/s, which was a time-dependent process. Notably, GEP-Cy5.5 was transported through the endocytosis process mediated by clathrin and macropinocytosis. The underlying absorptive mechanisms of GEP in vivo and in vitro were clarified, which provided the guidance for clinical medicine administration and could deepen the biological understanding of oral polysaccharides.
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http://dx.doi.org/10.1016/j.foodres.2021.110342DOI Listing
June 2021

Disposable masks release microplastics to the aqueous environment with exacerbation by natural weathering.

J Hazard Mater 2021 09 8;417:126036. Epub 2021 May 8.

Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, QC H3G 1M8, Canada.

The COVID-19 pandemic has driven explosive growth in the use of masks has resulted in many issues related to the disposal and management of waste masks. As improperly disposed masks enter the ocean, the risk to the marine ecological system is further aggravated, especially in the shoreline environment. The objective of this study is to explore the changing characteristics and environmental behaviors of disposable masks when exposed to the shoreline environment. The transformation of chain structure and chemical composition of masks as well as the decreased mechanical strength of masks after UV weathering were observed. The melt-blown cloth in the middle layer of masks was found to be particularly sensitive to UV irradiation. A single weathered mask can release more than 1.5 million microplastics to the aqueous environment. The physical abrasion caused by sand further exacerbated the release of microplastic particles from masks, with more than 16 million particles released from just one weathered mask in the presence of sand. The study results indicate that shorelines are not only the main receptor of discarded masks from oceans and lands, but also play host to further transformation of masks to plastic particles.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126036DOI Listing
September 2021

Trophic transfer potential of nTiO, nZnO, and triclosan in an algae-algae eating fish food chain.

Aquat Toxicol 2021 Jun 3;235:105824. Epub 2021 Apr 3.

Water Science and Environmental Engineering Research Center, College of Chemical and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.

Little is known about the trophic transfer of nanoparticles and personal care products via dietary exposure in an algae-algae eating fish food chain. The bioaccumulation of nano-TiO (P25 - nTiO), nano-ZnO (nZnO), and triclosan (TCS) in eight different combinations were explored in this study through algae, Asterococcus superbus, to fish, Gyrinocheilus aymonieri. Results found the bioaccumulation of TCS changed with algal biomass, while the bioaccumulation of Ti and Zn varied with the amount of lipids and proteins in algal cells. In algae, Ti was in the form of nTiO and Zn in the form of zinc ion. Due to dietary exposure, Ti and Zn quantity in fish was closely related to that in algae. The quantity of Ti and Zn in algae and fish exposed to the interaction of nTiO * nZnO* TCS was higher than that in other treatments. The uptake of Ti and Zn in algae exposed to the interaction of nTiO * nZnO had been inhibited, and the corresponding fish also had less Ti and Zn in their tissues. nTiO-containing treatments had higher Ti proportion in muscle than gill in fish. Treatment nZnO had the most Zn in gill, whereas nZnO * TCS-containing treatments had higher Zn proportion in gut than other tissues. No observation of TCS in fish in all treatments suggested the removal and metabolism of TCS might be induced by tissue recovery and acclimation. This is the first report on trophic transfer of mixed nanoparticles and personal care product in an algae-algae eating fish two-stage food chain.
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http://dx.doi.org/10.1016/j.aquatox.2021.105824DOI Listing
June 2021

Microfluidic Based Whole-Cell Biosensors for Simultaneously On-Site Monitoring of Multiple Environmental Contaminants.

Front Bioeng Biotechnol 2021 9;9:622108. Epub 2021 Mar 9.

Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL, Canada.

Monitoring of environmental contaminants serves a vital role in proactive environmental management and pollution control. Research efforts have been centered on the development of robust whole-cell biosensors in recent years. However, data acquisition, multiple contaminants detection and biosafety issues limit the on-site application of such biosensors. Microfluidic system exhibits great potential to face these challenges via coupling biosensors. Here, we prospect a novel microfluidic based whole-cell biosensor (MWCB) for multiplexing monitoring of diverse contaminants, and design strategies to further increase the specificity, sensitivity and accuracy, reduce signal delay and expand shelf life of the proposed MWCB for on-site environmental applications. The development of MWCB demands multidisciplinary cooperation, and the sensing platforms are highly promising for real-world contaminants monitoring.
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http://dx.doi.org/10.3389/fbioe.2021.622108DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8006271PMC
March 2021

The effect of pressure variation on droplet size distribution of dispersed oil under simulated deep-water conditions.

Heliyon 2021 Mar 11;7(3):e06291. Epub 2021 Mar 11.

Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL A1B 3X5, Canada.

Droplet size distribution of dispersed oil in deep-water is critical to the transport and biodegradation of spilled oil in deep-sea. Few studies have focused on the effects of pressure on chemically dispersed oil through experiments. This study thus simulated how the crude oil homogenously pre-dispersed by Corexit 9500A using baffled flasks would behave after being exposed to deep-water conditions. Key factors included dispersant-to-oil ratio (DOR), mixing energy (energy dissipation rate and Kolmogorov microscale), and pressure (up to 150 bar). The variations of pressure were demonstrated to have insignificant effects on the size distribution of pre-dispersed oil. Both the average and medium droplet sizes were correlated negatively with DOR and mixing energy in an established model with a p-value ≤ 0.0011. The log-normal and log-logistic distributions provided a reasonable fit to simulate the droplet size distribution. The two parameters of log-logistic distribution were dependent on DOR and mixing energy with a p-value < 0.005. The results would be valuable to advance the understanding of the behaviours and trajectories of chemically dispersed oil under deep-water conditions. The research helped provide more scientific evidence to improve the understanding of dispersed oil behaviours under high pressure and support deep-sea oil spill research and potential extension of the existing results from shallow water to deep water conditions.
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http://dx.doi.org/10.1016/j.heliyon.2021.e06291DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7966848PMC
March 2021

A novel peptide identified from skin secretions of Bombina maxima possesses LPS-neutralizing activity.

Biochem Biophys Res Commun 2021 04 6;550:107-112. Epub 2021 Mar 6.

Department of Urology, The First Affiliated Hospital of Kunming Medical University, Kunming, 650032, Yunnan, China. Electronic address:

Lipopolysaccharide (LPS) is a major pathogenic factor in endotoxin shock or sepsis. Most antibiotics have little clinical anti-endotoxin activity, but some antimicrobial peptides (AMPs) have been shown to be effective in blocking LPS. We identified a novel peptide from the skin secretions of Bombina maxima (B. _maxima) by challenging the skin of frogs with an LPS solution. Peptide 2 has an amino acid sequence of LVGKLLKGAVGDVCGLLPIC. Peptide 2 possesses low hemolytic activity, low cytotoxicity against RAW 264.7 cells, and strong anti-inflammatory activity. Moreover, peptide 2 plays an anti-inflammatory role by inhibiting inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). A biolayer interferometry (BLI) assay indicated that peptide 2 binds to LPS with strong affinity and that this interaction has an affinity constant (K) value of 1.05 × 10 M. A survival study showed that peptide 2 possesses potent LPS-neutralizing activity to protect LPS-treated mice from death. In conclusion, we have identified a potent peptide with LPS neutralizing activity, which lays a foundation for future research and development.
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http://dx.doi.org/10.1016/j.bbrc.2021.02.131DOI Listing
April 2021

Interactions between microplastics and oil dispersion in the marine environment.

J Hazard Mater 2021 02 15;403:123944. Epub 2020 Sep 15.

Northern Region Persistent Organic Pollutant Control (NRPOP) Laboratory, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL A1B 3X5, Canada. Electronic address:

Microplastics (MPs) and spilled oil are both major concerns in the marine environment. In this study, we investigated if and how MPs would interact with crude oil and potentially reduce the effectiveness of oil dispersants applied during oil spill response operations. With the addition of dispersant, MPs and oil (covered by dispersants through their hydrophobic tails) formed MPs-oil-dispersant agglomerates that were found to exist from the surface layer to the bottom of the seawater column. Their resurfacing and sinking led to a decrease in oil dispersion effectiveness. Effects of MP concentration, MP aging, and dispersant-to-oil volumetric ratios (DORs) on oil dispersion were examined. We found that the dispersion effectiveness of light oil and heavy oil decreased 38.26 % and 38.25 %, respectively, with an increased MP concentration. The dispersion effectiveness of light oil and heavy oil was 82.86 ± 10.87 % and 40.39 ± 4.96 % with pristine MPs and increased up to 109.75 ± 0.71 % and 58.30 ± 0.00 % when using MPs aged for 56 days. MPs reduced oil dispersion effectiveness under different DORs. The findings of this first report to understand the interactions among MPs, oil and dispersants have provided fundamental insights that may influence future decision making on the selection and use of oil spill response strategies.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123944DOI Listing
February 2021

Review of aquatic toxicity of pharmaceuticals and personal care products to algae.

J Hazard Mater 2021 05 19;410:124619. Epub 2020 Nov 19.

Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Civil Engineering, Memorial University, NL A1B 3X5, St. John's Canada. Electronic address:

Pharmaceuticals and Personal Care Products (PPCPs) have been frequently detected in the environment around the world. Algae play a significant role in aquatic ecosystem, thus the influence on algae may affect the life of higher trophic organisms. This review provides a state-of-the-art overview of current research on the toxicity of PPCPs to algae. Nanoparticles, contained in personal care products, also have been considered as the ingredients of PPCPs. PPCPs could cause unexpected effects on algae and their communities. Chlorophyta and diatoms are more accessible and sensitive to PPCPs. Multiple algal endpoints should be considered to provide a complete evaluation on PPCPs toxicity. The toxicity of organic ingredients in PPCPs could be predicted through quantitative structure-activity relationship model, whereas the toxicity of nanoparticles could be predicted with limitations. Light irradiation can change the toxicity through affecting algae and PPCPs. pH and natural organic matter can affect the toxicity through changing the existence of PPCPs. For joint and tertiary toxicity, experiments could be conducted to reveal the toxic mechanism. For multiple compound mixture toxicity, concentration addition and independent addition models are preferred. However, there has no empirical models to study nanoparticle-contained mixture toxicity. Algae-based remediation is an emerging technology to prevent the release of PPCPs from water treatment plants. Although many individual algal species are identified for removing a few compounds from PPCPs, algal-bacterial photobioreactor is a preferable alternative, with higher chances for industrial applications.
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http://dx.doi.org/10.1016/j.jhazmat.2020.124619DOI Listing
May 2021

Effect of punicalagin on multiple targets in streptozotocin/high-fat diet-induced diabetic mice.

Food Funct 2020 Dec 19;11(12):10617-10634. Epub 2020 Nov 19.

Department of Pharmacy, Wuhan University, Renmin Hospital, Wuhan 430060, Hubei Province, China.

Type 2 diabetes has a series of metabolic aberrations accompanied by chronic hyperglycemia, along with various comorbidities. In recent reports, punicalagin from pomegranate has been reported to exert hypoglycemic effects against diabetes. The goal of the current research was to investigate the therapeutic effectiveness and elucidate the mechanisms of punicalagin underlying type 2 diabetes. Type 2 diabetes was induced by a high-fat diet (HFD) combined with streptozotocin (STZ) injection in C57BL/6J mice. Punicalagin was administered daily by oral gavage for 4 weeks. The results indicated that high FBG (fasting blood glucose), dyslipidemia and associated islet, liver and kidney injury were observed in the model group mice. Through metabolomics analysis, it was found that the administration of punicalagin could regulate 24 potential biomarkers and their related metabolic pathways. Moreover, the pathological changes in the liver and kidney were mainly mediated by reducing gluconeogenesis and increasing glycogenesis via stimulation of the PI3K/AKT signaling pathway and regulation of the HMGB-1/TLR4/NF-κB signaling pathway, which simultaneously interrelated to ten main pathological pathways. In addition, we confirmed the positive role of punicalagin in glucosamine-induced HepG2 cells and HG-induced HK-2 cells through related mechanistic studies in vitro. In conclusion, these findings suggested that the multi-effect and multi-target action mode of punicalagin had a significant hypoglycemic effect and a protective effect on diabetes mellitus. Punicalagin might serve as an alternative functional food or as a clinical supplemental therapy for the diabetic population to ameliorate metabolic syndrome.
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http://dx.doi.org/10.1039/d0fo01275kDOI Listing
December 2020

Occurrence and biodegradation of hydrocarbons at high salinities.

Sci Total Environ 2021 Mar 22;762:143165. Epub 2020 Oct 22.

Center for Natural Resources, Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA. Electronic address:

Hypersaline environments are found around the world, above and below ground, and many are exposed to hydrocarbons on a continuous or a frequent basis. Some surface hypersaline environments are exposed to hydrocarbons because they have active petroleum seeps while others are exposed because of oil exploration and production, or nearby human activities. Many oil reservoirs overlie highly saline connate water, and some national oil reserves are stored in salt caverns. Surface hypersaline ecosystems contain consortia of halophilic and halotolerant microorganisms that decompose organic compounds including hydrocarbons, and subterranean ones are likely to contain the same. However, the rates and extents of hydrocarbon biodegradation are poorly understood in such ecosystems. Here we describe hypersaline environments potentially or likely to become contaminated with hydrocarbons, including perennial and transient environments above and below ground, and discuss what is known about the microbes degrading hydrocarbons and the extent of their activities. We also discuss what limits the microbial hydrocarbon degradation in hypersaline environments and whether there are opportunities for inhibiting (oil storage) or stimulating (oil spills) such biodegradation as the situation requires.
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http://dx.doi.org/10.1016/j.scitotenv.2020.143165DOI Listing
March 2021

Nglycosylation shields apoplastic effector PsXEG1 from a specific host aspartic protease.

Proc Natl Acad Sci U S A 2020 11 20;117(44):27685-27693. Epub 2020 Oct 20.

Department of Plant Pathology, Nanjing Agricultural University, 210095 Nanjing, China;

Hosts and pathogens are engaged in a continuous evolutionary struggle for physiological dominance. A major site of this struggle is the apoplast. In -soybean interactions, PsXEG1, a pathogen-secreted apoplastic endoglucanase, is a key focal point of this struggle, and the subject of two layers of host defense and pathogen counterdefense. Here, we show that N-glycosylation of PsXEG1 represents an additional layer of this coevolutionary struggle, protecting PsXEG1 against a host apoplastic aspartic protease, GmAP5, that specifically targets PsXEG1. This posttranslational modification also attenuated binding by the previously described host inhibitor, GmGIP1. N-glycosylation of PsXEG1 at N174 and N190 inhibited binding and degradation by GmAP5 and was essential for 's full virulence contribution, except in GmAP5-silenced soybeans. Silencing of GmAP5 reduced soybean resistance against WT but not against deletion strains of The crucial role of N-glycosylation within the three layers of defense and counterdefense centered on PsXEG1 highlight the critical importance of this conserved apoplastic effector and its posttranslational modification in -host coevolutionary conflict.
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http://dx.doi.org/10.1073/pnas.2012149117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7959567PMC
November 2020

Sulfate removal using colloid-enhanced ultrafiltration: performance evaluation and adsorption studies.

Environ Sci Pollut Res Int 2021 Feb 24;28(5):5609-5624. Epub 2020 Sep 24.

Process Engineering, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL, A1B 3X5, Canada.

Colloid-enhanced ultrafiltration (CEUF), i.e., micellar-enhanced ultrafiltration (MEUF) and polymer-enhanced ultrafiltration (PEUF), was investigated to remove sulfate ions from aqueous solution in batch experiments, using cetyltrimethylammonium (CTAB) and poly(diallydimethylammonium chloride) (PDADMAC) as colloids, respectively. Ultrafiltration performance was evaluated under different initial concentrations of sulfate (0-20 mM) and CTAB/PDADMAC (0-100 mM). The highest retention rate (> 99%) was found in dilute sulfate solutions. At high sulfate concentrations (e.g., 10 mM), a dosage of 50 mM CTAB or PDADMAC can retain approximately 90% of sulfate ions. Though concentration polarization behavior was observed, membrane characterization indicated that the fouling was reversible and membranes can be reused. Furthermore, adsorption equilibrium and kinetics studies show that Freundlich isotherm and pseudo-second-order kinetics can describe the sulfate-colloid interaction, indicating that the surface of absorbents are heterogeneous and the rate-controlling step is chemisorption. Both MEUF and PEUF show potential as effective separation techniques in removing sulfate from aqueous solutions. Under the same conditions examined, PEUF shows advantages over MEUF in its higher retention at lower polymer-to-sulfate ratios, cleaner effluent, and higher adsorption capacity, but compromises on severer flux decline and a tendency of membrane fouling. To overcome this disadvantage, membranes with higher molecular weight cut-off can be used.
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http://dx.doi.org/10.1007/s11356-020-10884-zDOI Listing
February 2021

Atomic Hourglass and Thermometer Based on Diffusion of a Mobile Dopant in VO.

J Am Chem Soc 2020 Sep 27;142(36):15513-15526. Epub 2020 Aug 27.

Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.

Transformations between different atomic configurations of a material oftentimes bring about dramatic changes in functional properties as a result of the simultaneous alteration of both atomistic and electronic structure. Transformation barriers between polytypes can be tuned through compositional modification, generally in an immutable manner. Continuous, stimulus-driven modulation of phase stabilities remains a significant challenge. Utilizing the metal-insulator transition of VO, we exemplify that mobile dopants weakly coupled to the crystal lattice provide a means of imbuing a reversible and dynamical modulation of the phase transformation. Remarkably, we observe a time- and temperature-dependent evolution of the relative phase stabilities of the M and R phases of VO in an "hourglass" fashion through the relaxation of interstitial boron species, corresponding to a 50 °C modulation of the transition temperature achieved within the same compound. The material functions as both a chronometer and a thermometer and is "reset" by the phase transition. Materials possessing memory of thermal history hold promise for applications such as neuromorphic computing, atomic clocks, thermometry, and sensing.
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http://dx.doi.org/10.1021/jacs.0c07152DOI Listing
September 2020

Fish Waste Based Lipopeptide Production and the Potential Application as a Bio-Dispersant for Oil Spill Control.

Front Bioeng Biotechnol 2020 3;8:734. Epub 2020 Jul 3.

NRPOP Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL, Canada.

There is a growing acceptance worldwide for the application of dispersants as a marine oil spill response strategy. The development of more effective dispersants with less toxicity and higher biodegradability would be a step forward in improving public acceptance and regulatory approvals for their use. By applying advances in environmental biotechnology, a bio-dispersant agent with a lipopeptide biosurfactant produced by N3-1P as the key component was formulated in this study. The economic feasibility of producing biosurfactant (a high-added-value bioproduct) from fish waste-based peptone as a nutrient substrate was evaluated. Protein hydrolyzate was prepared from cod liver and head wastes obtained from fish processing facilities. Hydrolysis conditions (i.e., time, temperature, pH and enzyme to substrate level) for preparing protein hydrolyzates were optimized by response surface methodology using a factorial design. The critical micelle dilution (CMD) value for biosurfactant produced from the fish liver and head waste generated peptones was 54.72 and 47.59 CMD, respectively. Biosurfactant product generated by fish liver peptone had a low critical micelle concentration of 0.18 g L and could reduce the surface tension of distilled water to 27.9 mN/m. Structure characterization proved that the generated biosurfactant product belongs to the lipopeptide class. An alternative to the key surfactant dioctyl sulfosuccinate sodium (DOSS) used in Corexit 9500 has been proposed based on a binary mixture of lipopeptides and DOSS that exhibited synergistic effects. Using the standard baffled flask test, a high dispersion efficiency of 76.8% for Alaska North Slope oil was achieved at a biodispersant composition of 80/20 (v/v) of lipopeptides/DOSS. The results show that fish waste can be utilized to produce a more effective, environmentally acceptable and cost-efficient biodispersant that can be applied to oil spills in the marine environment.
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http://dx.doi.org/10.3389/fbioe.2020.00734DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7347989PMC
July 2020

Photocatalytic ozonation of offshore produced water by TiO nanotube arrays coupled with UV-LED irradiation.

J Hazard Mater 2021 01 11;402:123456. Epub 2020 Jul 11.

Ecosystem Science, Fisheries and Oceans Canada, Ottawa, ON, K1A 0E6, Canada.

Offshore produced water (OPW) containing hazardous substances such as polycyclic aromatic hydrocarbons (PAHs) needs to be treated prior to discharge. This study integrated a photocatalytic ozonation system with TiO nanotube arrays (TNA) and UV-light-emitted diode (UV-LED) irradiation and applied to treat OPW. Experimental and modeling efforts were made to evaluate the degradation efficiencies of PAHs, examine the behaviors of the OPW composition (e.g., phenols, iodide, and bromide), and investigate the oxidation intermediates and the associated toxicity and biodegradability. The results indicated that ozone significantly enhanced the oxidation rates and removed the PAHs within 30 min, while the TNA showed strong photocatalytic capability. In the early stage, iodide was a strong ozone competitor, accelerating phenol degradation but inhibiting PAH oxidation, whereas UV-LED fortified the effect. The degradation of aromatics was altered by iodide and bromide at different stages. The contributions of four toxicants to the acute toxicity of OPW were quantified and ranked (PAHs > bromoform > phenols > dibromopentane). The EC value increased from 3 % to 57 %, and the biodegradability was doubled with less footprint in 28-day biodegradation tests. Overall, it is recommended to sequentially oxidize the matrix of OPW by ozonation and PAHs by the UV-LED/TNA/ozone system.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123456DOI Listing
January 2021

An integrated offshore oil spill response decision making approach by human factor analysis and fuzzy preference evaluation.

Environ Pollut 2020 Jul 2;262:114294. Epub 2020 Mar 2.

Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Memorial University of Newfoundland, Faculty of Engineering and Applied Science, St. John's, NL, A1B 3X5, Canada.

Human factors/errors (such as inappropriate actions by operators and unsafe supervision by organizations) are a primary cause of oil spill incidents. To investigate the influences of active operational failures and unsafe latent factors in offshore oil spill accidents, an integrated human factor analysis and decision support process has been developed. The system is comprised of a Human Factors Analysis and Classification System (HFACS) framework to qualitatively evaluate the influence of various factors and errors associated with the multiple operational stages considered for oil spill preparedness and response (e.g., oil spill occurrence, spill monitoring, decision making/contingency planning, and spill response); coupled with quantitative data analysis by Fuzzy Set Theory and the Technique for Order Preference by Similarity to Ideal Solution (Fuzzy-TOPSIS) to enhance decision making during response operations. The efficiency of the integrated human factor analysis and decision support system is tested with data from a case study to generate a comprehensive priority rank, a robust sensitivity analysis, and other theoretical/practical insights. The proposed approach improves our knowledge on the significance of human factors/errors on oil spill accidents and response operations; and provides an improved support tool for decision making.
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http://dx.doi.org/10.1016/j.envpol.2020.114294DOI Listing
July 2020

Integration of Fuzzy Matter-Element Method and 3D-QSAR Model for Generation of Environmentally Friendly Quinolone Derivatives.

Int J Environ Res Public Health 2020 05 6;17(9). Epub 2020 May 6.

Northern Region Persistent Organic Pollution Control (NRPOP) Laboratory, Civil Engineering, Faculty of Engineering and Applied Science, Memorial University, St. John's, NL A1B 3X5, Canada.

The environmental pollution of quinolone antibiotics (QAs) has caused rising public concern due to their widespread usage. In this study, Gaussian 09 software was used to obtain the infrared spectral intensity (IRI) and ultraviolet spectral intensity (UVI) of 24 QAs based on the Density Functional Theory (DFT). Rather than using two single-factor inputs, a fuzzy matter-element method was selected to calculate the combined effects of infrared and ultraviolet spectra (CI). The Comparative Molecular Field Analysis (CoMFA) was then used to construct a three-dimensional quantitative structure-activity relationship (3D-QSAR) with QAs' molecular structure as the independent variable and CI as the dependent variable. Using marbofloxacin and levofloxacin as target molecules, the molecular design of 87 QA derivatives was carried out. The developed models were further used to determine the stability, functionality (genetic toxicity), and the environmental effects (bioaccumulation, biodegradability) of these designed QA derivatives. Results indicated that all QA derivatives are stable in the environment with their IRI, UVI, and CI enhanced. Meanwhile, the genetic toxicity of the 87 QA derivatives increased by varying degrees (0.24%-29.01%), among which the bioaccumulation and biodegradability of 43 QA derivatives were within the acceptable range. Through integration of fuzzy matter-element method and 3D-QSAR, this study advanced the QAs research with the enhanced CI and helped to generate the proposed environmentally friendly quinolone derivatives so as to aid the management of this class of antibiotics.
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http://dx.doi.org/10.3390/ijerph17093239DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7246649PMC
May 2020

Microbial eco-physiological strategies for salinity-mediated crude oil biodegradation.

Sci Total Environ 2020 Jul 15;727:138723. Epub 2020 Apr 15.

The Northern Region Persistent Organic Pollution (NRPOP) Control Laboratory, Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL A1B 3X5, Canada.

Salinity variability strongly affects the behaviors of oil degrading bacteria for spilled oil biodegradation in the marine environment. However, limited studies explored the strategies of microbes on salinity-mediated crude oil biodegradation. In this study, a halotolerant bio-emulsifier producer, Exiguobacterium sp. N41P, was examined as a model strain for Alaska North Slope (ANS) crude oil (0.5%, v/v) biodegradation. Results indicated that Exiguobacterium sp. N41P could tolerant a wide range of salinity (0-120 g/L NaCl) and achieve the highest degradation efficiency under the salinity of 15 g/L NaCl due to the highest biofilm formation ability. Moreover, increased salinity induced decreased cell surface hydrophobicity and a migration of microbial growth from oil phase to aqueous phase, leading to limited bio-emulsifier productivity and depressed degradation of insoluble long-chain n-alkanes while enhancing the degradation of relative soluble naphthalene. Research findings illustrated the microbial eco-physiological mechanism for spilled oil biodegradation under diverse salinities and advanced the understanding of sophisticated marine crude oil biodegradation process.
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http://dx.doi.org/10.1016/j.scitotenv.2020.138723DOI Listing
July 2020
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