|
| |||||||||||
| ||
|
| ||
|
| ||
|
| ||
| ||
| ||
|
| ||
|
| ||
|
| ||
|
| ||
|
| ||
|
| Bloc-Notes/Notepad |
The current study investigates the impact of recharging of partially treated wastewater through an infiltration basin on the groundwater aquifer quality parameters. A monitoring program supported by a geographic information analysis (GIS) tool was used to conduct this study. Groundwater samples from the entire surrounding boreholes located downstream the infiltration basin, in addition to samples from the recharged wastewater coming from the Beit Lahia wastewater treatment (BLWWTP), were monitored and analysed between 2011 and 2014. The analysis was then compared with the available historical data since 2008. Results revealed a groundwater replenishment with the groundwater level increased by 1.0–2.0 m during the study period. It also showed a slight improvement in the groundwater quality parameters, mainly a decrease in TDS, Cl− and NO3− levels by 5.5, 17.1 and 20%, respectively, resulting from the relatively better quality of the recharged wastewater. Nevertheless, the level of boron and ammonium in the groundwater wells showed a significant increase over time by 96 and 100%, respectively. Moreover, the infiltration rate was slowed down in time due to the relatively high level of total suspended solid (TSS) in the infiltrated wastewater.
Rhamnolipid (Rh) is a biosurfactant produced by the bacterial Pseudomonas aeruginosa. This present study investigates rhizospheric strain C1501 of P. aeruginosa with an accession number KF976394 with the best production of rhamnolipid: a biosurfactant. The partially purified rhamnolipid from strain C1501 and Tween 80 was tested on mycelial growth of wild strain C1136. The enzyme activities involved in biodegradation, as well as necrosis induction on the tested weeds, were performed using scanning electron microscopy. It was observed that the different concentrations of rhamnolipid tested enhanced the dry mycelia weight yield of Lasiodiplodia pseudotheobromae which has been established to be producing a phytotoxic metabolite for killing weeds. It was observed that strain C1136 had a high level of cellulase and xylanase enzyme activities during this study. The scanning electron microscopy showed that the mutant strain of C1136 combined with 0.003% v/v of rhamnolipid enhances biodegradability and a high level of necrosis on the tested weeds compared with that on the untreated weeds. The highest CMCase activities and xylanase activities were obtained on the fourth day from the phytotoxic metabolite produced from the mutant strain of L. pseudotheobromae when combined with 0.003% v/v of rhamnolipid. This study has shown that rhamnolipid can serve as an adjuvant in order to enhance the penetrability of bioherbicide active ingredient for controlling weeds.
Thermal treatment of polychlorinated biphenyls (PCB) contaminated soil was shown in earlier work to generate polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF). In this study, the PCDD/F were studied arising during the remediation of p,p′-DDT contaminated soil by thermal desorption. Three kinds of soil (sandy, clayey and lateritic soil) were tested to investigate the effect of soil texture on PCDD/F formation. Those soils were artificially polluted with p,p′-DDT, obtaining a concentration level of 100 mg/kg. Thermal desorption experiments were conducted for 10 min at 300 °C in an air atmosphere. The total concentration of PCDD/F generated for three soils were 331, 803 and 865 ng/kg, respectively, and TeCDD and TeCDF were dominant among all PCDD/F congeners. After thermal desorption, the total amount of PCDD/F generated both in soil and in off-gas correlated positively with the amount of DDT added to soil. In addition, a possible pathway of the formation of PCDD/F was presented.
Although cell phones have been used worldwide, some adverse and toxic effects were reported for this communication technology apparatus. To analyze in vivo effects of exposure to radiofrequency-electromagnetic field (RF-EMF) on protein expression in rat testicular proteome, 20 Sprague-Dawley rats were exposed to 900 MHz RF-EMF for 0, 1, 2, or 4 h/day for 30 consecutive days. Protein content of rat testes was separated by high-resolution two-dimensional electrophoresis using immobilized pH gradient (pI 4–7, 7 cm) and 12% acrylamide and identified by MALDI-TOF/TOF-MS. Two protein spots were found differentially overexpressed (P < 0.05) in intensity and volume with induction factors 1.7 times greater after RF-EMF exposure. After 4 h of daily exposure for 30 consecutive days, ATP synthase beta subunit (ASBS) and hypoxia up-regulated protein 1 precursor (HYOU1) were found to be significantly up-regulated. These proteins affect signaling pathways in rat testes and spermatogenesis and play a critical role in protein folding and secretion in the endoplasmic reticulum. Our results indicate that exposure to RF-EMF produces increases in testicular proteins in adults that are related to carcinogenic risk and reproductive damage. In light of the widespread practice of men carrying phones in their pockets near their gonads, where exposures can exceed as-tested guidelines, further study of these effects should be a high priority.
Soil degradation by salinity and accumulation of trace elements such as cadmium (Cd) in the soils are expected to become one of the most critical issues hindering sustainable production and feeding the increasing population. Biochar (BC) has been known to protect the plants against soil salinity and heavy metal stress. A soil culture study was performed to evaluate the effect of BC on wheat (Triticum aestivum L.) growth, biomass, and reducing Cd and sodium (Na) uptake grown in Cd-contaminated saline soil under ambient conditions. Soil salinity decreased the plant growth, biomass, grain yield, chlorophyll contents, and gas exchange parameters and caused oxidative stress in plants compared with Cd stress alone. Salt stress increased Cd and Na uptake and reduced the potassium (K) and zinc (Zn) uptake by plants. AB-DTPA-extractable Cd and soil electrical conductivity (ECe) increased under salt stress compared to the soil without NaCl stress. Biochar application improved the plant growth and reduced the Cd and Na uptake except in plants treated with higher BC and salt stress (5.0% BC + 50 mM NaCl). Biochar application reduced the oxidative stress in plants and modified the antioxidant enzyme activities, and reduced the bioavailable Cd under salt stress. The positive effects of BC under lower salt stress while the negative effects of BC under higher BC and salt levels indicated that BC doses should be used with great care in higher soil salinity levels simultaneously contaminated with Cd to avoid the negative effects of BC on growth and metal uptake.
The aim of the present work was to extend our knowledge on the variability of trace metals in sea urchin tissues, focusing on seasonal fluctuations (2010 February for "winter," May for "spring," August for "summer," November for "autumn") in the three different sampling sites of Algerian west coast (Oran Harbor (S1), Ain Defla (S2), and Hadjaj (belonging to Mostaganem City S3)). For this purpose, the bioavailability (metal indices) and bioaccumulation (metal concentrations in soft tissues) of heavy metals (Zn, Cu, Pb, and Cd), the physiological characteristics (e.g., biological indices such as condition index (CI), repletion index (RI), gonad index (GI)), and the biometric parameters (diameter (D) and the height (H)) of sea urchins Paracentrotus lividus were assessed and related to seasons and sites. To investigate the metal bioavailability to sea urchins more precisely, the metal indices were used as a reliable tool in the present work, instead of the metal concentrations only. The interest to standardize metal concentrations with the weight of the urchin test is to overcome the metal burden variations in the soft tissues of urchin related to the seasonal weight changes of the soft body of animal. We evidence that the most contaminated sites were S1 and S2. Furthermore, it should be noted that the bioavailability of metals, corresponding to the values of metal indices, is also more pronounced in S1 and S2 compared to that measured in S3. Thus, a correlation is observed between seasonal metal content in urchin tissues from the three sites and the corresponding metal indices. The high metal concentrations were obtained during the period when RI and CI were highest. So, it appears that the bioaccumulation of metals in sea urchins of the three sites studied is significantly influenced by the reproductive cycle and diet, feeding activity, and physiological state of these organisms. We noticed that the sea urchins from the sites S1 and S2 were small in size. It is probable that these animals, whose internal tissues contained high concentrations of metals, have been exposed to metal pollution, which might have affected both their growth and altered their physiological capacity. This approach is very original and might be used in the monitoring of the quality of coastal waters, and the present work provided a useful data set for Mediterranean monitoring network.
The use of modelling tools to support decision-makers to plan air quality policies is now quite widespread in Europe. In this paper, the Regional Integrated Assessment Tool (RIAT+), which was designed to support policy-maker decision on optimal emission reduction measures to improve air quality at minimum costs, is applied to the Porto Urban Area (Portugal). In addition to technological measures, some local measures were included in the optimization process. Case study results are presented for a multi-objective approach focused on both NO2 and PM10 control measures, assuming equivalent importance in the optimization process. The optimal set of air quality measures is capable to reduce simultaneously the annual average concentrations values of PM10 and NO2 in 1.7 and 1.0 μg/m3, respectively. This paper illustrates how the tool could be used to prioritize policy objectives and help making informed decisions about reducing air pollution and improving public health.
In the eutrophic Ghar El Melh Lagoon (GML, Tunisia), the distribution of heterotrophic prokaryotes, pico- and nanophytoplankton was studied at five stations in November 2012 at the single cell level, along with environmental factors. Flow cytometry analysis of ultraplankton (<10 μm) resolved (i) two heterotrophic prokaryote groups, low and high nucleic acid contents (LNA and HNA, respectively), and (ii) eight to nine ultraphytoplankton groups (cryptophyte-like cells, two nanoeukaryote subgroups, two picoeukaryote subgroups and three Synechococcus-like cells subgroups). Prochlorococcus was not detected. According to redundancy analysis (RDA), a significant difference was found in the distribution of the ultraplankton between stations (F = 2.61, p < 0.05); maximum proliferations of heterotrophic prokaryotes were observed in the inner parts of the lagoon at stations 3, 4 and 5 affected by urban, agricultural and industrial discharges. Ultraphytoplankton concentrations were the highest near the outlet of the lagoon at stations 1 and 2 influenced by freshwater outflow and oligotrophic Mediterranean water inflow, respectively. At station 1, the large ultraphytoplankton concentration derives from the high abundance of cryptophyte-like cells favoured by the freshwater outflow whereas at station 2, the input of oligotrophic Mediterranean water enhanced the abundance of Synechococcus and picoeukaryotes at the expense of nanoeukaryotes. Two trophic regimes were thus differentiated in GML.
The use of treated grey water (GW) for home gardens, peri-urban agriculture and landscaping is becoming popular in many water stressed countries such as Oman. This study aims to investigate the treatment efficacy, health and chemical concerns, cost-benefits and maintenance protocol of a GW treatment system as well as the effect of irrigation with GW on crop yield. Therefore, a decentralized homemade GW treatment system was installed in a newly constructed house in Muscat, Oman and studied over a 2-year period. The treated GW was found to be suitable for irrigation as per Omani standards. GW when mixed with kitchen effluent substituted the use of nutrient supplements for plants and did not show any harmful chemical or biological contamination. The capital cost of the system was around US $980, and the annual operating cost was US $78 with annual income and savings from the system being around US $572 indicating a payback period of nearly 2 years. It was found that the system required simple but regular maintenance particularly cleaning of the top layer of the filter. It can be concluded from this study that such a GW system should be technically, economically and environmentally feasible in Oman. Also, wider acceptance by the general public to the idea of GW reuse will help in mitigating the water shortage problem of the country to some extent.
| Related Articles |
Population and function analysis of cultivable bacteria associated with spores of arbuscular mycorrhizal fungus Gigaspora margarita.
3 Biotech. 2017 May;7(1):8
Authors: Long L, Lin Q, Yao Q, Zhu H
Abstract
This study was aimed to investigate the diversity and function of bacterial population associated with Gigaspora margarita spores. The fungus was propagated in sterilized sand/soil pots using alfalfa (Medicago sativa), grain sorghum (Sorghum bicolor), or maize (Zea mays) as host plants, or in sterilized vermiculite pots using alfalfa as host plants, respectively. Bacteria were isolated from the new-formed spores using diluted plate method, and typical bacterial isolates were identified according to 16S rRNA gene phylogenetic analysis. Total 43 bacterial isolates affiliated to three phyla and 23 genera were obtained. The spore-associated bacterial communities were obviously different among the four source spores, suggesting that plant species or substrates could influence the bacterial population. Bacillus and Streptomyces were most frequently associated with the fungal spores. Function analysis of these bacteria by plate tests, it was found that about 30.2% isolates stimulated the spore germination, five out of seven tested isolates improved the hyphal growth, total 57.5% of the tested isolates solubilized phosphorus at different levels, 15% isolates degraded chitin, and a few isolates suppressed the growth of Escherichia coli or Staphylococcus aureus. In pot experiment, three bacterial isolates (belonging to Curtobacterium, Ensifer, or Bacillus, respectively) displayed improvement effect on alfalfa growth and/or the colonization of roots by G. margarita.
PMID: 28391471 [PubMed - in process]
|
|
Publication date: Available online 9 April 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Herbert Kaltner, Tamás Szabó, Krisztina Fehér, Sabine André, Sára Balla, Joachim C. Manning, László Szilágyi, Hans-Joachim Gabius
The emerging significance of recognition of cellular glycans by lectins for diverse aspects of pathophysiology is a strong incentive for considering development of bioactive and non-hydrolyzable glycoside derivatives, for example by introducing S/Se atoms and the disulfide group instead of oxygen into the glycosidic linkage. We report the synthesis of 12 bivalent thio-, disulfido- and selenoglycosides attached to benzene/naphthalene cores. They present galactose, for blocking a plant toxin, or lactose, the canonical ligand of adhesion/growth-regulatory galectins. Modeling reveals unrestrained flexibility and inter-headgroup distances too small to bridge two sites in the same lectin. Inhibitory activity was first detected by solid-phase assays using a surface-presented glycoprotein, with relative activity enhancements per sugar unit relative to free cognate sugar up to nearly 10fold. Inhibitory activity was also seen on lectin binding to surfaces of human carcinoma cells. In order to proceed to characterize this capacity in the tissue context monitoring of lectin binding in the presence of inhibitors was extended to sections of three types of murine organs as models. This procedure proved to be well-suited to determine relative activity levels of the glycocompounds to block binding of the toxin and different human galectins to natural glycoconjugates at different sites in sections. The results on most effective inhibition by two naphthalene-based disulfides and a selenide raise the perspective for broad applicability of the histochemical assay in testing glycoclusters that target biomedically relevant lectins.
Publication date: Available online 9 April 2017
Source:Bioorganic & Medicinal Chemistry
Author(s): Arun K. Ghosh, Margherita Brindisi, Prasanth R. Nyalapatla, Jun Takayama, Jean-Rene Ella-Menye, Sofiya Yashchuk, Johnson Agniswamy, Yuan-Fang Wang, Manabu Aoki, Masayuki Amano, Irene T. Weber, Hiroaki Mitsuya
Based upon molecular insights from the X-ray structures of inhibitor-bound HIV-1 protease complexes, we have designed a series of isophthalamide-derived inhibitors incorporating substituted pyrrolidines, piperidines and thiazolidines as P2-P3 ligands for specific interactions in the S2-S3 extended site. Compound 4b has shown an enzyme Ki of 0.025 nM and antiviral IC50 of 69 nM. An X-ray crystal structure of inhibitor 4b-HIV-1 protease complex was determined at 1.33 Å resolution. We have also determined X-ray structure of 3b-bound HIV-1 protease at 1.27 Å resolution. These structures revealed important molecular insight into the inhibitor–HIV-1 protease interactions in the active site.
