细化搜索
结果 1-10 的 28
Hydrocarbonoclastic bacterial species growing on hexadecane: Implications for bioaugmentation in marine ecosystems
2020
Rodrigues, Edmo Montes | Cesar, Dionéia Evangelista | Santos de Oliveira, Renatta | de Paula Siqueira, Tatiane | Tótola, Marcos Rogério
of bioaugmentation strategies are an obstacle for damage mitigation caused by oil spills in marine environments. Cells added to the contaminated sites are quickly lost by low adherence to the contaminants, rendering ineffective. This study used two hydrocarbonoclastic species - Rhodococcus rhodochrous TRN7 and Nocardia farcinica TRH1 cells - growing in mineral medium containing hexadecane to evaluate cell distribution in a crude-oil contaminated marine water. Cell affinity to hydrophobic compounds was quantified using Microbial Adhesion to Hydrocarbons test and analysis of fatty acids profile was performed using the Microbial Identification System. Bioremediation simulations were set up and cell populations of both strains were quantified by Fluorescent in situ Hybridization. R. rhodochrous and N. farcinica reached up to 97% and 60% of adhesion to hexadecane, respectively. The carbon source had more influence on the fatty acid profiles of both strains than the microbial species. The presence of 45.24% of 13:0 anteiso on total fatty acids in R. rhodochrous and 12.35% of saturated fatty acids with less than 13 carbons atoms in N. farcinica, as well as the occurrence of fatty alcohols only in presence of hexadecane in both species, are indicators that fatty acid changes are involved in the adaptation of the cells to remain at the water/oil interface. Cell quantification after bioremediation simulations revealed an increase in the density of both species, suggesting that the bioremediation strategies resulted on the increase of hydrocarbonoclastic species and up to 27.9% of all prokaryotic microbial populations in the microcosms were composed of R. rhodochrous or N. farcinica. These findings show the potential of application of these two bacterial strains in bioaugmentation of hydrocarbon-contaminated marine ecosystems.R. rhodochrous TRN7 and N. farcinica TRH1 hydrocarbonoclastic strains modify the fatty acid profile and increases density, optimizing hydrocarbons biodegradation.
显示更多 [+] 显示较少 [-]Effects of waterborne exposure to environmentally relevant concentrations of selenite on reproductive function of female zebrafish: A life cycle assessment
2021
Mo, Aijie | Wang, Xiaolin | Yuan, Yongchao | Liu, Chunsheng | Wang, Jianghua
Recently, bioaccumulation of dietary organic selenium (Se) in the ovaries and inhibition of reproduction in female aquatic animals have been reported. However, there is limited data on the subtle reproductive impacts of waterborne exposure to inorganic Se in fish. Here, zebrafish embryos (2 h post-fertilization) were exposed to solutions with environmentally relevant levels of Na₂SeO₃ with concentrations of 0 (control), 7.98 ± 0.31, 25.14 ± 0.15, and 79.60 ± 0.81 μg Se/L for 120 d until they reached sexual maturity. Female zebrafish were selected for reproductive toxicity assessment. In the early embryonic stage, whole-mount in situ hybridization of zebrafish embryos showed that waterborne Na₂SeO₃ exposure did not affect the observed location of vasa expression in primordial germ cells at 24, 48, and 72 h post-fertilization. Life-cycle exposure to 25.14 ± 0.15 and 79.60 ± 0.81 μg Se/L Na₂SeO₃ did not change the testosterone and 17β-estradiol contents in female zebrafish at the endpoint of exposure, but significantly reduced the proportion of early vitellogenic oocytes and mature oocytes. Follicle maturity retardation was accompanied by changes in transcriptional levels of the genes related to the hypothalamus-pituitary-gonad-liver (HPGL) axis. Transcriptional levels of cyp19a and lhr in the ovary were down-regulated, while the transcriptional level of fshr in the ovaries was up-regulated. In the 21-day cumulative spawning experiment, Na₂SeO₃ (25.14 ± 0.15 and 79.60 ± 0.81 μg Se/L) caused fewer eggs to be produced. Additionally, the malformation of zebrafish offspring significantly increased in the group exposed to 79.60 ± 0.81 μg Se/L. In conclusion, for the first time, this study shows that life-cycle exposure to environmentally relevant concentrations of waterborne Na₂SeO₃ significantly delays ovarian maturation and reduces the fertility of the female zebrafish.
显示更多 [+] 显示较少 [-]Differences in chemical contaminants bioaccumulation and ecotoxicology biomarkers in Mytilus edulis and Mytilus galloprovincialis and their hybrids
2022
Sussarellu, Rossana | Chouvelon, Tiphaine | Aminot, Yann | Couteau, Jerome | Loppion, Geraldine | Dégremont, Lionel | Lamy, Jean-baptiste | Akcha, Farida | Rouxel, Julien | Berthelin, Clothilde | Briaudeau, Tifanie | Izagirre, Urtzi | Mauffret, Aourell | Grouhel, Anne | Burgeot, Thierry
The Mytilus mussels are spread all over the world and many related species coexist in several areas and can produce hybrid offspring. Mussels have been used for decades in national and international programs to monitor chemical contamination in the environment. Differences in bioaccumulation and biotransformation abilities between species and their hybrids should be evaluated to assess the comparability of the results obtained within the international biomonitoring programs. The objective of this study was to characterize bioaccumulation abilities and biomarker responses in Mytilus edulis, Mytilus galloprovincialis and their hybrids via an in situ transplantation experimentation on their progenies. Four mussel groups (M. edulis, M. galloprovincialis and two hybrids batches) issued from genetically characterized parents were transplanted for one year in Charente Maritime (France) to ensure their exposure to identical sources of contamination. The bioaccumulation of several families of contaminants (trace metals, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, polychlorinated biphenyls), the response of several biomarkers (DNA strand breaks level, lysosomal membrane stability, metallothionein content, acetylcholine esterase activity) and some physiological parameters (growth, mortality, gonadal development), were analyzed. Differences were observed between species, however they were contaminant-specific. Variations in contaminants levels were observed between progenies, with higher levels of Cu, PBDE, PCB in M. edulis, and higher levels of Cd, Hg, Zn in M galloprovincialis. This study demonstrated that variations in contaminant bioaccumulation and different biomarker responses exist between Mytilus species in the field. Data on species or the presence of hybrid individuals (or introgression) is an important additional parameter to add to biomonitoring programs databases.
显示更多 [+] 显示较少 [-]Membrane Distillation for Strategic Water Treatment Applications: Opportunities, Challenges, and Current Status
2020
Duong, Hung Cong | Ansari, Ashley Joy | Hailemariam, Ruth Habte | Woo, Yun Chul | Pham, Thao Manh | Ngo, Lan Thi | Dao, Duong Thanh | Nghiem, Long Duc
PURPOSE OF REVIEW: Membrane distillation (MD) has been known as a promising water treatment process for many years. However, despite its advantages, MD has never been able to compete with other processes for industrial water treatment and supply. Instead, it has been orientated towards several unique strategic water treatment applications. This review aims to uncover the opportunities and technical challenges pertinent to the MD process and the current status of its strategic water treatment applications most notably including decentralised small-scale desalination for fresh water provision in remote areas, hybridisation with forward osmosis (FO) for treatment of challenging polluted waters, regeneration of liquid desiccant solutions for air conditioning, and treatment of acid effluents for beneficial reuse. RECENT FINDINGS: Pilot and small-scale MD systems have been demonstrated for decentralised desalination using various renewable energy sources to supply fresh water in remote, rural areas and on ships where other desalination processes are inefficient or unfeasible. For this strategic desalination application, MD is technically viable, but more works on configuration modification and process optimisation are required to reduce the process energy consumption and water production costs. For the three other strategic applications, the technical viability of the MD process has been proved by extensive lab-scale researches, but its economic feasibility is still questionable due to the lack of large-scale evaluation and the uncertain costs of MD systems. The orientation of MD towards strategic water treatment applications is clear. However, huge efforts are required to facilitate these applications at commercial and full scale.
显示更多 [+] 显示较少 [-]Study and evaluation of the characteristics of saline wastewater (brine) produced by desalination and industrial plants
2022
Panagopoulos, Argyris
Desalination and industrial plants all around the world generate large amounts of saline wastewater (brine). The discharge of brine from facilities poses a severe environmental threat, while at the same time, the opportunity to recover resources is being lost as discharged brine is rich in valuable metals that could be recovered as salts/minerals. To this aim, this study presents and analyzes for the first time the characteristics of different brine effluents (from industries such as desalination, oil and gas production, petrochemical, aquaculture, pharmaceutical, textile) to prevent environmental pollution and to recover valuable resources (i.e., salts, minerals, metals, chemicals) enabling the concept of waste-to-resource (circular water economy model). The results revealed that the common salinity values in brine effluents range from 0.5 to 150 g/L, while the only exception is the produced water from the oil and gas industry (up to 400 g/L). Brine effluents from all sectors contain sodium, chloride, calcium, and potassium ions in high concentrations, while the production of common salts such as NaCl, CaCl₂, and MgCl₂ from brine can be economically profitable. Besides common ions, precious metals such as lithium, rubidium, and cesium are present in low concentrations (<25 mg/L); however, their extraction from brine effluents can be significantly profitable due to their very high sale price. The treatment and valorization of brine can be implemented by the hybridization of membrane-based, chemical, biological, and thermal-based technologies/processes in minimal and zero liquid discharge (MLD/ZLD) systems.
显示更多 [+] 显示较少 [-]Transient behavior of non-toxic natural and hybrid multi-layer desiccant composite materials for water extraction from atmospheric air
2021
Jawarneh, Ali M. | AL-Oqla, Faris M. | Jadoo, Anas Abu
Producing clean water via renewable solar energy and available low-cost natural resources is one of paramount issues for the near future sustainable cleaner production theme to promote civilization. This work investigates the transient behavior of a solar-driven clean water extraction system from air by various desiccant natural and hybrid composite materials. Different single composite desiccant materials, hybrid single composite desiccant material, and hybrid multi-layers composite desiccant materials were examined using an efficient design of a solar glass box with four glass faces and square base setup. Nine different single composite desiccant materials were compared for water production from atmospheric air considering jute, wool, cotton, and maize starch host materials. The effect of CaCl₂ solution concentration on the hybridization of such materials was also investigated to examine and optimize their water productivity efficiency. Thirteen hybrid multi-layer starch-based composite desiccant material types were utilized. Different layer combinations and weight percentages of hybrid composite desiccant materials were optimized based on the performance in the single hybrid composites stages including wool/CaCl₂/starch, jute/CaCl₂/starch, and cotton/CaCl₂/starch. Results have indicated that the transient behavior of water productivity of composite desiccants increased as the wool percentage by mass in the composite has been increased. The transient behavior of water productivity of both single and hybrid multi-layer composites reached its maximum at 1:00 o’clock PM. The quality of extracted water was analyzed using total dissolved solids (TDS) test and found to be within the excellent category of clean water suitable for human being. Water generated from the samples that contain only natural fibers and starch was the cleaner and non-toxic.
显示更多 [+] 显示较少 [-]Rapid and sensitive detection of Karenia mikimotoi by loop-mediated isothermal amplification combined with a lateral flow dipstick
2022
Han, Xiaotian | Zhao, Ting | Yan, Tian | Yu, Rencheng
Harmful algal blooms frequently occur in various coastal regions worldwide, deteriorating marine ecology and causing huge economic losses. Therefore, developing a potential method for rapid detection of harmful algae species is highly necessitated. In this study, a loop-mediated isothermal amplification (LAMP) method coupled with a lateral flow dipstick (LFD) was developed for detecting the harmful algae Karenia mikimotoi. In this method, the internal transcribed spacer (ITS) sequence of K. mikimotoi was used as the template, and the corresponding specific primers were designed by the online software PrimerExplorer V5. Biotin was labeled on the 5′ end of forward inner primer (FIP), and the LAMP reaction was performed under the determined optimal conditions of 63℃ and 60 min. The lowest concentration of K. mikimotoi DNA tested using LAMP was 3.3 × 10–¹ pg/μL. Additionally, a 6-FAM-labeled probe was designed and displayed on the LFD after hybridization of the amplified product with the probe. The results demonstrated that LAMP-LFD could be a promising approach for detecting and monitoring harmful algae due to its high sensitivity and specificity.
显示更多 [+] 显示较少 [-]Integration of complete ensemble empirical mode decomposition with deep long short-term memory model for particulate matter concentration prediction
2021
The atmospheric particulate matter (PM) with a diameter of 2.5 μm or less (PM2.5) is one of the key indicators of air pollutants. Accurate prediction of PM2.5 concentration is very important for air pollution monitoring and public health management. However, the presence of noise in PM2.5 data series is a major challenge of its accurate prediction. A novel hybrid PM2.5 concentration prediction model is proposed in this study by combining complete ensemble empirical mode decomposition (CEEMD) method, Pearson’s correlation analysis, and a deep long short-term memory (LSTM) method. CEEMD was employed to decompose historical PM2.5 concentration data to different frequencies in order to enhance the timing characteristics of data. Pearson’s correlation was used to screen the different frequency intrinsic-mode functions of decomposed data. Finally, the filtered enhancement data were inputted to a deep LSTM network with multiple hidden layers for training and prediction. The results evidenced the potential of the CEEMD-LSTM hybrid model with a prediction accuracy of approximately 80% and model convergence after 700 training epochs. The secondary screening of Pearson’s correlation test improved the model (CEEMD-Pearson) accuracy up to 87% but model convergence after 800 epochs. The hybrid model combining CEEMD-Pearson with the deep LSTM neural network showed a prediction accuracy of nearly 90% and model convergence after 650 interactions. The results provide a clear indication of higher prediction accuracy of PM2.5 with less computation time through hybridization of CEEMD-Pearson with deep LSTM models and its potential to be employed for air pollution monitoring.
显示更多 [+] 显示较少 [-]Advances in multiplex molecular detection technologies for harmful algae
2022
Fu, Hanyu | Zhang, Chunyun | Wang, Yuanyuan | Chen, Guofu
As the eutrophication of natural water bodies becomes more and more serious, the frequency of outbreaks of harmful algal blooms (HABs) mainly formed by harmful algae also increases. HABs have become a global ecological problem that poses a serious threat to human health and food safety. Therefore, it is extremely important to establish methods that can rapidly detect harmful algal species for early warning of HABs. The traditional morphology-based identification method is inefficient and inaccurate. In recent years, the rapid development of molecular biology techniques has provided new ideas for the detection of harmful algae and has become a research hotspot. The current molecular detection methods for harmful algal species mainly include fluorescence in situ hybridization, sandwich hybridization, and quantitative PCR (qPCR), but all of these methods can only detect single harmful algal species at a time. The establishment of methods for the simultaneous detection of multiple harmful algal species has become a new trend in the development of molecular detection technology because various harmful algal species may coexist in the natural water environment. The established molecular techniques for multiple detections of harmful algae mainly include gene chip, multiplex PCR, multiplex qPCR, massively parallel sequencing, antibody chip, and multiple isothermal amplification. This review mainly focuses on the principles, advantages and disadvantages, application progress, and application prospects of these multiple detection technologies, aiming at providing effective references not only for the fisheries but also for economic activities, environment, and human health.
显示更多 [+] 显示较少 [-]Impact of invasive ant species on native fauna across similar habitats under global environmental changes
2021
Siddiqui, Junaid Ali | Bamisile, Bamisope Steve | Mūsá K̲h̲ān̲, Muḥammad | Islam, Waqar | Hafeez, Muhammad | Bodlah, Imran | Xu, Yijuan
Biotic invasions can predominantly alter the dynamics, composition, functions, and structure of natural ecosystems. Social insects, particularly ants, are among the most damaging invasive alien species. Invasive ant species are among the supreme threats to ecosystems. There are about 23 species of invasive ants recorded worldwide, according to the ant invasive databases. The ecological impacts of invasive ants comprise predation, hybridization, and competition with native species that changes the ecosystem processes with the biodiversity loss and upsurge of pests. The effects of invasion on native fauna in the same habitats might be catastrophic for the native community through various ecological mechanisms, e.g., habitat disturbance, resource competition, limiting the foraging activity of native species, and various other indirect mechanisms of invasive species. Invasive species may have harmful impacts on habitats and devastating effects on natural flora and fauna, and stopping these new species from being introduced is the most effective way to deter future invasions and maintain biodiversity. This paper reviews the literature to evaluate the effects of invasive ant species on the native species, including vertebrates, invertebrates, and plants sharing the same habitats as the non-native species under global environmental changes. We also highlighted the various management strategies that could be adopted in minimizing the adverse effects of these invasive ant species on the natural ecosystem. To this end, strategies that could regulate the mode and rate of invasion by these alien ant species are the most effective ways to deter future invasions and maintain biodiversity.
显示更多 [+] 显示较少 [-]