Search results for "contamination"
showing 10 items of 916 documents
The asexual enchytraeid worm Cognettia sphagnetorum (Oligochaeta) has increased Cu resistance in polluted soil
2001
We studied Cu resistance in the asexual (reproduction through fragmentation) enchytraeid worms (Cognettia sphagnetorum, Oligochaeta) originating from two sites: one uncontaminated, and another contaminated by heavy metals. Adult worms were smaller and population density was lower at the polluted site. However, adults from the contaminated site had better survival in Cu-contaminated soil, but lower survival as juveniles (fragments). As we do not know the genetic basis of Cu resistance of the worms, it may have been reached by acclimatization via induced Cu regulation. Because fragmentation is the only mode of reproduction, all phenotypic properties (including resistance) of a parental genera…
Potential of nisin-incorporated sodium caseinate films to control Listeria in artificially contaminated cheese
2010
International audience; A sodium caseinate film containing nisin (1000 IU/cm(2)) was produced and used to control Listeria innocua in an artificially contaminated cheese. Mini red Babybel cheese was chosen as a model semi-soft cheese. L. innocua was both surface- and in-depth inoculated to investigate the effectiveness of the antimicrobial film as a function of the distance from the surface in contact with the film. The presence of the active film resulted in a 1.1 log CFU/g reduction in L. innocua counts in surface-inoculated cheese samples after one week of storage at 4 degrees C as compared to control samples. With regard to in-depth inoculated cheese samples, antimicrobial efficiency wa…
Spatial distribution, contamination assessment and potential ecological risk of some trace metals in the surface sediments of the Gulf of Tunis, Nort…
2021
To evaluate the trace metals contamination status in the Gulf of Tunis, forty one sediment samples were analyzed using different approaches. According to certain contamination and ecological risk indices (Contamination Factor, Geoaccumulation index and Ecological risk index), Hg has the highest contamination level while pollution by Ni, Pb, Cd and Cr was absent. The highest concentrations of trace metals were found in sediments collected from the offshore and coastal areas located opposite the main exchange points with the gulf particularly, the Mejerda and Meliane Rivers, the Khalij Channel, Ghar El Melh and El Malah lagoons, Tunis Lake and Sebkhat Ariana. However, further ecological indic…
Predicting the effectiveness of oil recovery strategies in the marine polluted environment
2018
Abstract Many recent studies have focused their attention on the physiological stress experienced by marine organisms in measuring ecotoxicological responses. Here we suggest a new approach for investigating the effects of an anthropogenic pollutant on Life-History (LH) traits of marine organisms, to provide stakeholders and policy makers an effective tool to evaluate the best environmental recovery strategies and plans. A Dynamic Energy Budget (DEB), coupled with a biophysical model was used to predict the effects of a six-month oil spill on Mytilus galloprovincialis' LH traits and to test two potential recovery strategies in the central Mediterranean Sea. Oxygen consumption rates were use…
25S rDNA-based molecular monitoring of glomalean fungi in sewage sludge-treated field plots
2001
Recycling of sewage wastes in agriculture is likely to affect the biological activity of soils through contamination of ecosystems by pathogens and metallic or organic micropollutants. The impact of sewage sludge spreading under field conditions on arbuscular mycorrhiza (AM) formation by a community of glomalean fungi was evaluated using a nested polymerase chain reaction (PCR) and discriminating primers based on 25S rDNA polymorphisms to detect different fungal species within root systems. Medicago truncatula was grown in soil of field plots amended or not with a composted sewage sludge, spiked or not with organic or metallic micropollutants. Overall AM development in roots decreased with …
Ecological mechanisms can modify radiation effects in a key forest mammal of Chernobyl
2019
International audience; Nuclear accidents underpin the need to quantify the ecological mechanisms which determine injury to ecosystems from chronic low-dose radiation. Here, we tested the hypothesis that ecological mechanisms interact with ionizing radiation to affect natural populations in unexpected ways. We used large-scale replicated experiments and food manipulations in wild populations of the rodent, Myodes glareolus, inhabiting the region near the site of the Chernobyl disaster of 1986. We show linear decreases in breeding success with increasing ambient radiation levels with no evidence of any threshold below which effects are not seen. Food supplementation of experimental populatio…
Antifungal activity of peracetic acid against toxigenic fungal contaminants of maize and barley at the postharvest stage
2021
Abstract Contamination of maize and barley grain during storage by the toxigenic fungi Aspergillus flavus (A. flavus) and Penicillium Verrucosum (P. verrucosum) is both an economic and a public health problem, especially in less industrialized countries. Peracetic acid (PA) is a compound used for the disinfection of food and food contact surfaces. Unlike other disinfectants, it leaves no toxic residues and its decomposition products (CH3COOH, O2 and H2O) are environmentally friendly. In order to apply PA to preserve maize and barley grain during storage, first, the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) against both fungi were determined in a 96-we…
Life history and spatial distribution of the enchytraeid wormCognettia sphagnetorum(Oligochaeta) in metal-polluted soil: Below-ground sink-source pop…
2001
We studied the life history, metal-avoidance behavior, spatial distribution, and population growth of enchytraeid worms (Cognettia sphagnetorum [Oligochaeta]) originating from two sites: one uncontaminated, and another patchily polluted by heavy metals. Effects of patchy soil contamination on populations were studied in microcosms. In uncontaminated soil, worms from the polluted site had lower viability and reduced growth rate as juveniles but higher growth rate as adults compared to worms from the unpolluted site. They were also smaller in size at fragmentation (reproduction). Worms from the polluted site reached a larger population size than worms from the unpolluted site. Hence, worms fr…
On the use of Persian gum for the development of antiviral edible coatings against murine norovirus of interest in blueberries.
2021
In the last decades, berries have been identified as important vehicles for the transmission of foodborne viruses and different strategies are being explored to eliminate or reduce viral contamination in these fruits. The aim of this work was to develop novel edible coatings with antiviral properties for inactivating and reducing murine norovirus (MNV). Firstly, the effect of gelatin (G) addition on Persian gum (PG) films was studied in terms of microstructural, mechanical, optical, and water barrier properties. The following PG:G ratios were considered: 100:0, 75:25, 50:50, 25:75, and 0:100. Microstructure analysis revealed the compatibility of both hydrocolloids since no phase separation …
Can phthalates move into the eggs of the loggerhead sea turtle Caretta caretta? The case of the nests on the Linosa Island in the Mediterranean Sea
2021
During the monitoring of Caretta caretta nests on the island of Linosa, 30 unhatched eggs from four nests were collected to study the presence of phthalates in their three components (shell, yolk, and albumen). Four phthalates, namely diethyl (DEP), dibutyl (DBP), di-(2-ethylhexyl) (DEHP), and dioctyl (DOTP) phthalic acid esters (PAE), which are widely used as additives in plastics, were detected in all egg components. The most frequently found phthalate was DBP, followed by DEHP in eggshell and yolk. Dimethyl- (DMP) and butylbenzyl-phthalate (BBP) were below the limits of detection for all samples. The high total phthalate recorded in the yolk suggests that contamination could arise by vit…