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Physiological and molecular responses of springtails exposed to phenanthrene and drought
2014
Holmstrup, Martin | Slotsbo, Stine | Schmidt, Stine N. | Mayer, Philipp | Damgaard, Christian | Sørensen, Jesper G.
Interaction between effects of hazardous chemicals in the environment and adverse climatic conditions is a problem that receives increased attention in the light of climate change. We studied interactive effects of phenanthrene and drought using a test system in which springtails (Folsomia candida Willem) were concurrently exposed to a sublethal phenanthrene level via passive dosing from silicone (chemical activity of 0.010), and sublethal drought from aqueous NaCl solutions (water activity of 0.988). Previous studies have shown that the combined effects of high levels of phenanthrene and drought, respectively, interact synergistically when using lethality as an end-point. Here, we hypothesized that phenanthrene interferes with physiological mechanisms involved in drought tolerance, and that drought influences detoxification of phenanthrene. However, this hypothesis was not supported by data since phenanthrene had no effect on drought-protective accumulation of myo-inositol, and normal water conserving mechanisms of F. candida were functioning despite the near-lethal concentrations of the toxicant. Further, detoxifying induction of cytochrome P450 and glutathione-S-transferase was not impeded by drought. Both phenanthrene and drought induced transcription of heat shock protein (hsp70) and the combined effect of the two stressors on hsp70 transcription was additive, suggesting that the cellular stress and lethality imposed by these levels of phenanthrene and drought were also additive.
Afficher plus [+] Moins [-]Green additive to upgrade biochar from spent coffee grounds by torrefaction for pollution mitigation
2021
Lee, Kuan-Ting | Du, Jyun-Ting | Chen, Wei-Hsin | Ubando, Aristotle T. | Lee, Keat Teong
A green approach using hydrogen peroxide (H₂O₂) to intensify the fuel properties of spent coffee grounds (SCGs) through torrefaction is developed in this study to minimize environmental pollution. Meanwhile, a neural network (NN) is used to minimize bulk density at different combinations of operating conditions to show the accurate and reliable model of NN (R² = 0.9994). The biochar produced from SCGs torrefied at temperatures of 200–300 °C, duration of 30–60 min, and H₂O₂ concentrations of 0–100 wt% is examined. The results reveal that the higher heating value (HHV) of biochar increases with rising temperature, duration, or H₂O₂ concentration, whereas the bulk density has an opposite trend. The HHV, ignition temperature, and bulk density of biochar from torrefaction at 230 °C for 30 min with a 100 wt% H₂O₂ solution (230-100%-TSCG) are 27.00 MJ∙kg⁻¹, 292 °C, and 120 kg∙m⁻³, respectively. This HHV accounts for a 29% improvement compared to that of untorrefied SCG. The contact angle (126°), water activity (0.51 aw), and moisture content (7.69%) of the optimized biochar indicate that it has higher resistance against biodegradation, and thereby can be stored longer. Overall, H₂O₂ is a green treatment additive for SCGs solid fuel. This study has successfully produced biochar with greater HHV and low bulk density at low temperatures. The green additive development can effectively reduce environmental pollutants and upgrade wastes into resources, and achieve “3E”, namely, environmental (non-polluting green additives), energy (biofuel), and circular economy (waste upgrade). In addition, the produced biochar has great potential in the fields of bioadsorbents and soil amendments.
Afficher plus [+] Moins [-]Dehalogenase-producing halophiles and their potential role in bioremediation
2020
Oyewusi, Habeebat Adekilekun | Wahab, Roswanira Abdul | Huyop, Fahrul
This review aims to briefly describe the potential role of dehalogenase-producing halophilic bacteria in decontamination of organohalide pollutants. Hypersaline habitats pose challenges to life because of low water activity (water content) and is considered as the largest and ultimate sink for pollutants due to naturally and anthropogenic activities in which a substantial amount of ecological contaminants are organohalides. Several such environments appear to host and support substantial diversity of extremely halophilic and halotolerant bacteria as well as halophilic archaea. Biodegradation of several toxic inorganic and organic compounds in both aerobic and anaerobic conditions are carried out by halophilic microbes. Therefore, remediation of polluted marine/hypersaline environments are the main scorching issues in the field of biotechnology. Although many microbial species are reported as effective pollutants degrader, but little has been isolated from marine/hypersaline environments. Therefore, more novel microbial species with dehalogenase-producing ability are still desired.
Afficher plus [+] Moins [-]Assessment of swimming associated health effects in marine bathing beach: An example from Morib beach (Malaysia)
2015
Praveena, Sarva Mangala | Pauzi, Norfasmawati Mohd | Hamdan, Munashamimi | Sham, Shaharuddin Mohd
A survey among beachgoers was conducted to determine the swimming associated health effects experienced and its relationship with beach water exposure behaviour in Morib beach. For beach water exposure behaviour, the highest frequency of visit among the respondents was once a year (41.9%). For ways of water exposure, whole body exposure including head was the highest (38.5%). For duration of water exposure, 30.8% respondents prefer to be in water for about 30min with low possibilities of accidental ingestion of beach water. A total of 30.8% of beachgoers in Morib beach were reported of having dermal symptoms. Bivariate analysis showed only water activity, water contact and accidental ingestion of beach water showed significant association with swimming associated health effects experienced by swimmers. This study output showed that epidemiological study can be used to identify swimming associated health effects in beach water exposed to faecal contamination.
Afficher plus [+] Moins [-]Anti-migraine activity of freeze-dried latex obtained from Calotropis gigantea Linn
2022
Bhatia, Saurabh | Al-Harrasi, Ahmed | Kumar, Arun | Behl, Tapan | Sehgal, Aayush | Singh, Sukhbir | Sharma, Neelam | Anwer, Md Khalid | Kaushik, Deepak | Mittal, Vineet | Chigurupati, Sridevi | Sharma, Pritam Babu | Aleya, Lotfi | Vargas-de-la-Cruz, Celia | Kabir, Md Tanvir
Migraine which is characterized by a pulsating headache affected an estimated population of 12% worldwide. Herbal products like latex derived from Calotropis gigantea R. Br. (Asclepiadaceae) are a representative intervention to treat migraine traditionally. However, post-harvesting stability issues of latex affect its biological potential. Freeze-drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable dried preparations. Latex derived from Calotropis gigantea (C. gigantea) was microencapsulated using chitosan by freeze-drying (FDCG) method and compared with sun ray–dried latex (ADCG). Current investigation was aimed to improve the shelf life of latex by freeze-drying microencapsulation technique and evaluation of its anti-migraine potential. Dried latex powders (ADCG and FDCG) were evaluated in terms of phenolic content, coloring strength, first-order kinetic, color parameters (L*, a*, b*, C*, and E*), moisture, water activity, solubility, and hygroscopicity. Additionally, apomorphine-induced climbing behavior, L-5-HTP–induced syndrome, and MK-801–induced hyperactivity were used to evaluate the anti-migraine potential of powdered latex. FDCG showed good physicochemical properties due to its higher concentration of phenolic and flavonoid contents. Moreover, FDCG significantly reduced the apomorphine-induced climbing behavior, L-5-HTP–induced syndrome, and MK-801–induced hyperactivity in a dose-dependent manner through an interaction of dopaminergic and serotonergic receptors. In conclusion, the method developed for shelf life improvement of latex offered maximum protection over a period of 10 weeks with retaining its natural biological potential; thus, it can be effectively utilized in the treatment or management of migraine. Anti-migraine effect of Calotropis gigantea freeze-dried latex by inhibition of dopamine and serotonin receptors (D1 and D2: dopamine receptors; 5-HT: serotonin receptors); yellow color represents serotonergic, and blue color indicates dopaminergic neurons
Afficher plus [+] Moins [-]Distribution and transfer of naturally occurring radionuclides and 137Cs in the freshwater system of the Plitvice Lakes, Croatia, and related dose assessment to wildlife by ERICA Tool
2021
Skoko, Božena | Babić, Dinko | Franić, Zdenko | Bituh, Tomislav | Petrinec, Branko
The aim of this study was to investigate the natural radioactivity of Plitvice Lakes, under the assumption that due to its status as a National Park, the area can be considered an example of a natural freshwater system. Also, considering the transfer parameter data as the largest source of uncertainty in radiological risk assessments, the impact of site-specific data on dose rate assessment, as opposed to currently available data, was investigated. The study included gamma and alpha spectrometric measurements of ²³⁸U, ²²⁶Ra, ²¹⁰Pb, ²²⁸Ra, and ⁴⁰K in water, sediment, and fish samples, as well as ¹³⁷Cs due to the coinciding of the study with the Fukushima accident. The content of naturally occurring radionuclides significantly varied in sediments of different Lakes, probably as a reflection of the different underlying geology of the area. Also, the ²¹⁰Pb distribution in sediments indicated an up to 312 Bq kg⁻¹ of the allochthonous contribution of this radionuclide at the beginning of the Lake’s watercourse, which probably entered into the lake system by the major inlet river with its steady decrease along downstream lakes. Low ⁴⁰K activity concentrations (27.5 ± 20.1 mBq L⁻¹) in the Lake’s waters might be one of the causes of increased ¹³⁷Cs activity concentrations in fish samples (1.5 ± 0.4 Bq kg⁻¹), which was found to be an order of magnitude higher than average values for different fish species from other Croatian freshwater systems (0.2 ± 0.1 Bq kg⁻¹). A temporary increase of ¹³⁷Cs activity concentrations was measured in water samples collected immediately after the Fukushima accident. Calculated site-specific sediment/water distribution coefficients and fish/water concentration ratios for radium and caesium were on average lower than generic ones found in the literature. Background dose rate assessments performed by the ERICA Tool indicated a profound impact of different input data on assessment results with water activity concentrations resulting in significantly higher dose rates (0.1–67 μGy h⁻¹) in comparison to sediment activity concentrations (0.03–9 μGy h⁻¹). An incremental dose rate due to ¹³⁷Cs was found to be in the range of < 0.001–0.023 μGy h⁻¹ which, in comparison to background dose rates, can be considered negligible.
Afficher plus [+] Moins [-]Plant-associated bacteria mitigate drought stress in soybean
2018
Martins, SamuelJulio | Rocha, GeisianeAlves | de Melo, HyrandirCabral | de Castro Georg, Raphaela | Ulhôa, CiranoJosé | de Campos Dianese, Érico | Oshiquiri, LeticiaHarumi | da Cunha, MarcosGomes | da Rocha, MaraRúbia | de Araújo, LeilaGarcês | Vaz, KarinaSantana | Dunlap, ChristopherA.
Agriculture accounts for ~ 70% of all water use and the world population is increasing annually; soon more people will need to be fed, while also using less water. The use of plant-associated bacteria (PAB) is an eco-friendly alternative that can increase crop water use efficiency. This work aimed to study the effect of some PAB on increasing soybean tolerance to drought stress, the mechanisms of the drought tolerance process, and the effect of the PAB on promoting plant growth and on the biocontrol of Sclerotinia sclerotiorum. PAB were isolated from soybean rhizosphere and S. sclerotiorum sclerotia. The strains identified as UFGS1 (Bacillus subtilis), UFGS2 (Bacillus thuringiensis), UFGRB2 and UFGRB3 (Bacillus cereus) were selected on their ability to grow in media with reduced water activity. Soybean plants were inoculated with the PAB and evaluated for growth promotion, physiological and molecular parameters, after drought stress. Under drought stress, UFGS2 and UFGRB2 sustained potential quantum efficiency of PSII (Fv/Fm), while a decrease was found in the control plants. Moreover, UFGS2 and UFGRB3 maintained the photosynthetic rates in non-stressed conditions compared to the control. UFGS2-treated plants showed a higher stomatal conductance and higher transpiration than the control, after drought stress. Some PAB-treated plants also had other beneficial phenotypes, such as increases in fresh and dried biomass relative to the control. Differential gene expression analysis of genes involved in plant stress pathways shows changes in expression in PAB-treated plants. Results from this study suggest that PAB can mitigate drought stress in soybean and may improve water efficiency under certain conditions.
Afficher plus [+] Moins [-]Gum arabic and collagen hydrolysate extracted from hide fleshing wastes as novel wall materials for microencapsulation of Origanum onites L. essential oil through complex coacervation
2020
Ocak, Bugra
Renewable resource–based biodegradable materials attract more attention than petroleum-based biodegradable materials to support the sustainable development of ecology. Obtaining collagen hydrolysate (CH) from hide fleshing wastes of leather industry is an environmentally friendly way to develop multifunctional materials that can contribute to technological advances in different industries. In this study, 2:1, 1:1, and 1 2 ratios of gum arabic (GA) and CH extracted from hide fleshing waste were used as wall materials to encapsulate Origanum onites L. essential oil (OOEO) using the complex coacervation method. The encapsulation yield and efficiency, functional group composition, particle size, morphology, and thermal stability of the obtained OOEO microcapsules were characterized. The results showed that the obtained microcapsules had high encapsulation yield and efficiency, as well as good functional properties such as uniform morphology and low water activity. The best mass ratio for the biopolymers (GA:CH) was 1:1. Scanning electron microscopy analysis showed that OOEO microcapsule samples had a spherical shape. FTIR analysis was performed on obtained microcapsules, confirming the molecular interactions between GA and CH. These findings can be useful in designing an ideal wall material using GA and CH for microencapsulation of essential oils by the complex coacervation method.
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