Exposure reduction of seed treatments through dehusking behaviour of the wood mouse <Emphasis Type="Bold">(</Emphasis><Emphasis Type="Italic">Apodemus sylvaticus</Emphasis><Emphasis Type="Bold">)</Emphasis>

Background, aim and scope  

Seed treatments are widely used on cereals and other annual crops throughout Europe. Most of the formulated pesticide is found on the outside of the seed, the husk. Risk assessments of seed treatments are especially needed for granivorous mice living in the agricultural landscape e.g. for registration using the guidance for risk assessment for birds and mammals (EFSA 2009). The dehusking of seeds before consumption is a known behaviour of these mammals, but so far, no quantitative data on the reduction of exposure of seed treatments by dehusking were published. Therefore, we aimed at providing a first quantitative estimate of this behaviour-related exposure reduction for the wood mouse (Apodemus sylvaticus) with different seed types.     

<Emphasis Type="Italic">Ailanthus Altissima</Emphasis> and <Emphasis Type="Italic">Phragmites Australis</Emphasis> for chromium removal from a contaminated soil

The comparative effectiveness for hexavalent chromium removal from irrigation water, using two selected plant species (Phragmites australis and Ailanthus altissima) planted in soil contaminated with hexavalent chromium, has been studied in the present work. Total chromium removal from water was ranging from 55 % (Phragmites) to 61 % (Ailanthus). After 360 days, the contaminated soil dropped from 70 (initial) to 36 and 41 mg Cr/kg (dry soil), for Phragmites and Ailanthus, respectively. Phragmites accumulated the highest amount of chromium in the roots (1910 mg Cr/kg_{(dry tissue)}), compared with 358 mg Cr/kg_{(dry tissue)} for Ailanthus roots. Most of chromium was found in trivalent form in all plant tissues. Ailanthus had the lowest affinity for Cr^VI reduction in the root tissues. Phragmites indicated the highest chromium translocation potential, from roots to stems. Both plant species showed good potentialities to be used in phytoremediation installations for chromium removal.     

Response of denitrification genes <Emphasis Type="Italic">nirS</Emphasis>, <Emphasis Type="Italic">nirK</Emphasis>, and <Emphasis Type="Italic">nosZ</Emphasis> to irrigation water quality in a Chinese agricultural soil

Purpose  

Denitrification is an important biochemical process in global nitrogen cycle, with a potent greenhouse gas product N₂O. Wastewater irrigation can result in the changes of soil properties and microbial communities of agricultural soils. The purpose of this study was to examine how the soil denitrification genes responded to different irrigation regimes.     

<Emphasis Type="Bold">Tracing lead contamination in foods in the city of Kolkata,India</Emphasis>

Lead isotopic ratios (LIR) of eight common food items, street dust, coal, diesel, sediments, lead ore and rainwater from India have been reported for the first time in this paper. This study characterized the source and extent of lead pollution in the different foodstuff consumed in Kolkata, a major metropolis of eastern India. The atmospheric lead input to the food items, sold openly in busy roadside markets of the city, has been quantified. The mean 207/206 and 208/206 LIRs of the eight food items ranged from 0.8847 to 0.8924 and 2.145 to 2.167, respectively. Diesel had the highest mean 207/206 and 208/206 values of 0.9015 and 2.1869, respectively, apart from the lead ore. The food items had a mean lead concentration between 3.78 and 43.35 mg kg^?1. The two ratio scatter plots of all the different environmental matrices were spread linearly between the uncontaminated Ichapur sediment and diesel. The 207/206 LIRs of the coal with a mean of 0.8777 did not fall in the linear trend, while the street dust and food samples overlapped strongly. The rainwater sample had a 207/206 LIR of 0.9007. Contaminated sediments in Dhapa, the repository of the city’s municipal garbage, had a mean 207/206 LIR of 0.8658. The corresponding value obtained from the sewage-fed vegetable grown there was 0.8058. The present study indicated that diesel was one of the main contributor to Pb pollution. The atmospheric lead contribution to the food items was in the range of 68.48–86.66 %.     

Acute,chronic and biochemical effects of chlorothalonil on <Emphasis Type="Italic">Agalychnis callidryas</Emphasis>, <Emphasis Type="Italic">Isthmohyla pseudopuma</Emphasis> and <Emphasis Type="Italic">Smilisca baudinii</Emphasis> tadpoles

Declines of amphibian populations have been a worldwide issue of concern for the scientific community during the last several decades. Efforts are being carried out to elucidate factors related to this phenomenon. Among these factors, pathogens, climate change, and environmental pollution have been suggested as possible causes. Regarding environmental pollutants, some pesticides are persistent in the environment and capable of being transported long distances from their release point. In Costa Rica, some pesticides have been detected in protected areas, at locations where amphibian populations have declined. Information about toxicity of pesticides used in Costa Rican agriculture to amphibians is still scarce, particularly for native species.Toxicity tests with chlorothalonil, a fungicide intensively used in Costa Rica, were carried out exposing tadpoles of three Costa Rican native species: Agalychnis callidryas, Isthmohyla pseudopuma, and Smilisca baudinii in order to evaluate acute and chronic toxicity as well as the biomarkers cholinesterase activity (ChE), glutathione-S transferase activity (GST), and lipid peroxidation (LPO).96-h LC₅₀: 26.6 (18.9–35.8) μg/L to A. callidryas, 25.5 (21.3–29.7) μg/L to I pseudopuma and 32.3 (26.3–39.7) μg/L to S. baudinii were determined for chlorothalonil. These three species of anurans are among the most sensitive to chlorothalonil according to the literature. Besides, GST was induced in S. baudinii after exposure to sub-lethal concentrations of chlorothalonil while evisceration occurred in S. baudinii and A. callidryas tadpoles exposed to lethal concentrations of the fungicide. Chronic exposure to sub-lethal concentrations accelerated development in S. baudinii and caused lesions in tail of S. baudinii and I. pseudopuma tadpoles. Our results demonstrate that chlorothalonil is highly toxic to native amphibian species and that low concentrations can cause biochemical responses related to phase II of biotransformation and effects on development.     

Polychlorinated biphenyls in farmed and wild <Emphasis Type="Italic">Onchorhynchus kisutch</Emphasis> and <Emphasis Type="Italic">Onchorhynchus mykiss</Emphasis> from the Chilean Patagonia

Purpose  

This paper analyses the presence of polychlorinated biphenyls (PCBs) in escaped: farmed and wild salmons in southern Chile, analysing their concentrations and congener profiles in two species (Oncorhynchus kisutch and Oncorhynchus mykiss).     

Combined treatment of contaminated soil with a bacterial <Emphasis Type="Italic">Stenotrophomonas</Emphasis> strain DXZ9 and ryegrass (<Emphasis Type="Italic">Lolium perenne</Emphasis>) enhances DDT and DDE remediation

Bioremediation of contaminated soils by a combinational approach using specific bacterial species together with ryegrass is a promising strategy, resulting in potentially highly efficient degradation of organic contaminants. The present study tested the combination of strain DXZ9 of Stenotrophomonas sp. with ryegrass to remove DDT and DDE contaminants from soil under natural conditions in a pot experiment. The strain DXZ9 was successfully colonized in the natural soil, resulting in removal rates of approximately 77% for DDT, 52% for DDE, and 65% for the two pollutants combined after 210 days. Treatment with ryegrass alone resulted in slightly lower removal rates (72 and 48%, respectively, 61% for both combined), while the combination of strain DXZ9 and ryegrass significantly (p?<?0.05) improved the removal rates to 81% for DDT and 55% for DDE (69% for both). The half-life of the contaminants was significantly shorter in combined treatment with DXZ9 and ryegrass compared to the control. The remediation was mostly due to degradation of the contaminants, as the net uptake of DDT and DDE by the ryegrass accounted for less than 3% of the total amount in the soil. DDT is reductively dechlorinated to DDD and dehydrochlorinated to DDE in the soil; the metabolites of DDE and DDD were multiple undefined substances. The toxicity of the soil was significantly reduced as a result of the treatment. The present study demonstrates that the bioremediation of soil contaminated with DDT and DDE by means of specific bacteria combined with ryegrass is feasible.     

Testing antimicrobial cleaner efficacy on gypsum wallboard contaminated with <Emphasis Type="Italic">Stachybotrys chartarum</Emphasis>

Goal, Scope and Background Reducing occupant exposure to indoor mold is the goal of this research, through the efficacy testing of antimicrobial cleaners. Often mold contaminated building materials are not properly removed, but instead surface cleaners are applied in an attempt to alleviate the problem. The efficacy of antimicrobial cleaners to remove, eliminate or control mold growth on surfaces can easily be tested on non-porous surfaces. However, the testing of antimicrobial cleaner efficacy on porous surfaces, such as those found in the indoor environment such as gypsum board can be more complicated and prone to incorrect conclusions regarding residual organisms. The mold Stachybotrys chartarum has been found to be associated with idiopathic pulmonary hemorrhage in infants and has been studied for toxin production and its occurrence in water damaged buildings. Growth of S. chartarum on building materials such as gypsum wallboard has been frequently documented. Methods Research to control S. chartarum growth using 13 separate antimicrobial cleaners on contaminated gypsum wallboard has been performed in laboratory testing. Popular brands of cleaning products were tested by following directions printed on the product packaging. Results A variety of gypsum wallboard surfaces were used to test these cleaning products at high relative humidity. The results indicate differences in antimicrobial efficacy for the six month period of testing. Discussion Results for the six types of GWB surfaces varied extensively. However, three cleaning products exhibited significantly better results than others. Lysol All-Purpose Cleaner-Orange Breeze (full strength) demonstrated results which ranked among the best in five of the six surfaces tested. Both Borax and Orange Glo Multipurpose Degreaser demonstrated results which ranked among the best in four of the six surfaces tested. Conclusions The best antimicrobial cleaner to choose is often dependent on the type of surface to be cleaned of S. chartarum contamination. For Plain GWB, no paint, the best cleaners were Borax, Lysol All-Purpose Cleaner-Orange Breeze (full strength), Orange Glo Multipurpose Degreaser, and Fantastik Orange Action. Recommendations and Perspectives These results are not meant to endorse the incomplete removal of mold contaminated building materials. However, it is recognized that complete removal may not always be possible and solutions to control mold regrowth may contribute to reduced occupant exposure. Current recommendations of removal and replacement of porous building materials should be followed. It is not the intension of this discussion to endorse any product. Reporting on the performance of these products under the stated conditions was and remains the only purpose. ESS-Submission Editor: Dr. Lee Young (youngrisk@bresnan.net)     

Toxicity of cobalt-complexed cyanide to <Emphasis Type="Italic">Oncorhynchus mykiss,Daphnia magna</Emphasis>, and <Emphasis Type="Italic">Ceriodaphnia dubia</Emphasis>

Background Cobalt cyanide complexes often result when ore is treated with cyanide solutions to extract gold and other metals. These have recently been discovered in low but significant concentrations in effluents from gold leach operations. This study was conducted to determine the potential toxicity of cobalt-cyanide complexes to freshwater organisms and the extent to which ultraviolet radiation (UV) potentiates this toxicity. Tests were also conducted to determine if humic acids or if adaptation to UV influenced sensitivity to the cyanide complexes. Methods Rainbow trout (Oncorhynchus mykiss), Daphnia magna, and Ceriodaphnia dubia were exposed to potassium hexacyanocobaltate in the presence and absence of UV radiation, in the presence and absence of humic acids. Cyano-cobalt exposures were also conducted with C. dubia from cultures adapted to elevated UV. Results With an LC50 concentration of 0.38 mg/L, cyanocobalt was over a 1000 times more toxic to rainbow trout in the presence of UV at a low, environmentally relevant irradiance level (4 μW/cm² as UVB) than exposure to this compound in the absence of UV with an LC50 of 112.9 mg/L. Toxicity was immediately apparent, with mortality occurring within an hour of the onset of exposure at the highest concentration. Fish were unaffected by exposure to UV alone. Weak-acid dissociable cyanide concentrations were observed in irradiated aqueous solutions of cyanocobaltate within hours of UV exposure and persisted in the presence of UV for at least 96 hours, whereas negligible concentrations were observed in the absence of UV. The presence of humic acids significantly diminished cyanocobalt toxicity to D. magna and reduced mortality from UV exposure. Humic acids did not significantly influence survival among C. dubia. C. dubia from UV-adapted populations were less sensitive to metallocyanide compounds than organisms from unadapted populations. Conclusions The results indicate that metallocyanide complexes may pose a hazard to aquatic life through photochemically induced processes. Factors that decrease UV exposure such as dissolved organic carbon or increased pigmentation would diminish toxicity.     

The role of the egg jelly coat in protecting<Emphasis Type="Italic">Hyla regilla</Emphasis> and<Emphasis Type="Italic">Bufo canorus</Emphasis> embryos from ultraviolet B radiation during development

BACKGROUND: Previous studies have suggested that Ultraviolet B (UVB) radiation may play a role in amphibian population declines. Some of these studies also indicate that egg hatching success is unaltered in some species of anurans as a result of UVB exposure. It has been proposed that the egg mass jelly provides photoprotection to the developing embryos. METHODS: Direct spectrophotometric scans of egg jelly, scans of egg jelly methanol extracts, and experimental manipulation in a solar simulator during development were all used to assess the role of egg mass jelly as a photoprotective agent. RESULTS/DISCUSSION: For Hyla regilla, scans of egg jelly and methanolic extracts (for mycosporine-like amino acid content) both displayed no absorption in the UV range. Experimental manipulation (removal of egg mass jelly) with both Hyla regilla and Bufo canorus egg masses in a solar simulator demonstrated that egg mass jelly played no apparent role in photoprotection of either of these species. CONCLUSIONS: Based on the results in this study it seems unlikely that the egg jelly coat is playing a crucial role in protecting developing embryos from the impact of UVB radiation.     

Side effects of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> var. kurstaki on the hymenopterous parasitic wasp <Emphasis Type="Italic">Trichogramma chilonis</Emphasis>

Most of the detrimental effects of using conventional insecticides to control crop pests are now well identified and are nowadays major arguments for replacing such compounds by the use of biological control agents. In this respect, the bacterium Bacillus thuringiensis var. kurstaki and Trichogramma (Hymenoptera: Trichogrammatidae) parasitic wasp species are both effective against lepidopterous pests and can actually be used concomitantly. In this work, we studied the potential side effects of B. thuringiensis var. kurstaki on Trichogramma chilonis females. We first evidenced an acute toxicity of B. thuringiensis on T. chilonis. Then, after ingestion of B. thuringiensis at sublethal doses, we focused on life history traits of T. chilonis such as longevity, reproductive success and the time spent on host eggs patches. The reproductive success of T. chilonis was not modified by B. thuringiensis while a significant effect was observed on longevity and the time spent on host eggs patches. The physiological and ecological meanings of the results obtained are discussed.     

Combined bioremediation of atrazine-contaminated soil by <Emphasis Type="Italic">Pennisetum</Emphasis> and <Emphasis Type="Italic">Arthrobacter</Emphasis> sp. strain DNS10

Strain DNS10 was isolated from the black soil collected from the northeast of China which had been cultivated with atrazine as the sole nitrogen source. Pennisetum is a common plant in Heilongjiang Province of China. The main objective of this paper was to evaluate the efficiency of plant–microbe joint interactions (Arthrobacter sp. DNS10 + Pennisetum) in atrazine degradation compared with single-strain and single-plant effects. Plant–microbe joint interactions degraded 98.10 % of the atrazine, while single strain and single plant only degraded 87.38 and 66.71 % after a 30-day experimental period, respectively. The results indicated that plant–microbe joint interactions had a better degradation effect. Meanwhile, we found that plant–microbe joint interactions showed a higher microbial diversity. The results of microbial diversity illustrated that the positive effects of cropping could improve soil microbial growth and activity. In addition, we planted atrazine-sensitive plants (soybean) in the soil after repair. The results showed that soybean growth in soil previously treated with the plant–microbe joint interactions treatment was better compared with other treatments after 20 days of growth. This was further proved that the soil is more conducive for crop cultivation. Hence, plant–microbe joint interactions are considered to be a potential tool in the remediation of atrazine-contaminated soil.     

Phytoextraction of lead-contaminated soil using vetivergrass (<Emphasis Type="Italic">Vetiveria zizanioides</Emphasis> L.), cogongrass (<Emphasis Type="Italic">Imperata cylindrica</Emphasis> L.) and carabaograss (<Emphasis Type="Italic">Paspalum conjugatum</Emphasis> L.)

Background, Aims and Scope The global problem concerning contamination of the environment as a consequence of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contributes to a variety of health effects such as decline in mental, cognitive and physical health of the individual. An alternative way of reducing Pb concentration from the soil is through phytoremediation. Phytoremediation is an alternative method that uses plants to clean up a contaminated area. The objectives of this study were: (1) to determine the survival rate and vegetative characteristics of three grass species such as vetivergrass, cogongrass and carabaograss grown in soils with different Pb levels; and (2) to determine and compare the ability of the three grass species as potential phytoremediators in terms of Pb accumulation by plants. Methods The three test plants: vetivergrass (Vetiveria zizanioides L.); cogongrass (Imperata cylindrica L.); and carabaograss (Paspalum conjugatum L.) were grown in individual plastic bags containing soils with 75 mg kg⁻¹ (37.5 kg ha⁻¹) and 150 mg kg⁻¹ (75 kg ha⁻¹) of Pb, respectively. The Pb contents of the test plants and the soil were analyzed before and after experimental treatments using an atomic absorption spectrophotometer. This study was laid out following a 3 × 2 factorial experiment in a completely randomized design. Results On the vegetative characteristics of the test plants, vetivergrass registered the highest whole plant dry matter weight (33.85–39.39 Mg ha⁻¹). Carabaograss had the lowest herbage mass production of 4.12 Mg ha⁻¹ and 5.72 Mg ha⁻¹ from soils added with 75 and 150 mg Pb kg⁻¹, respectively. Vetivergrass also had the highest percent plant survival which meant it best tolerated the Pb contamination in soils. Vetivergrass registered the highest rate of Pb absorption (10.16 ± 2.81 mg kg⁻¹). This was followed by cogongrass (2.34 ± 0.52 mg kg⁻¹) and carabaograss with a mean Pb level of 0.49 ± 0.56 mg kg⁻¹. Levels of Pb among the three grasses (shoots + roots) did not vary significantly with the amount of Pb added (75 and 150 mg kg⁻¹) to the soil. Discussion Vetivergrass yielded the highest biomass; it also has the greatest amount of Pb absorbed (roots + shoots). This can be attributed to the highly extensive root system of vetivergrass with the presence of an enormous amount of root hairs. Extensive root system denotes more contact to nutrients in soils, therefore more likelihood of nutrient absorption and Pb uptake. The efficiency of plants as phytoremediators could be correlated with the plants’ total biomass. This implies that the higher the biomass, the greater the Pb uptake. Plants characteristically exhibit remarkable capacity to absorb what they need and exclude what they do not need. Some plants utilize exclusion mechanisms, where there is a reduced uptake by the roots or a restricted transport of the metals from root to shoots. Combination of high metal accumulation and high biomass production results in the most metal removal from the soil. Conclusions The present study indicated that vetivergrass possessed many beneficial characteristics to uptake Pb from contaminated soil. It was the most tolerant and could grow in soil contaminated with high Pb concentration. Cogongrass and carabaograss are also potential phytoremediators since they can absorb small amount of Pb in soils, although cogongrass is more tolerant to Pb-contaminated soil compared with carabaograss. The important implication of our findings is that vetivergrass can be used for phytoextraction on sites contaminated with high levels of heavy metals; particularly Pb. Recommendations and Perspectives High levels of Pb in localized areas are still a concern especially in urban areas with high levels of traffic, near Pb smelters, battery plants, or industrial facilities that burn fuel ending up in water and soils. The grasses used in the study, and particularly vetivergrass, can be used to phytoremediate urban soil with various contaminations by planting these grasses in lawns and public parks. ESS-Submission Editor: Dr. Willie Peijnenburg (wjgm.peijnenburg@rivm.nl)     

Combined biocidal action of silver nanoparticles and ions against Chlorococcales (S<Emphasis Type="Italic">cenedesmus quadricauda</Emphasis>, <Emphasis Type="Italic">Chlorella vulgaris)</Emphasis> and filamentous algae (<Emphasis Type="Italic">Klebsormidium sp.</Emphasis>)

Despite the extensive research, the mechanism of the antimicrobial and biocidal performance of silver nanoparticles has not been unequivocally elucidated yet. Our study was aimed at the investigation of the ability of silver nanoparticles to suppress the growth of three types of algae colonizing the wetted surfaces or submerged objects and the mechanism of their action. Silver nanoparticles exhibited a substantial toxicity towards Chlorococcales Scenedesmus quadricauda, Chlorella vulgaris, and filamentous algae Klebsormidium sp., which correlated with their particle size. The particles had very good stability against agglomeration even in the presence of multivalent cations. The concentration of silver ions in equilibrium with nanoparticles markedly depended on the particle size, achieving about 6 % and as low as about 0.1 % or even less for the particles 5 nm in size and for larger ones (40–70 nm), respectively. Even very limited proportion of small particles together with larger ones could substantially increase concentration of Ag ions in solution. The highest toxicity was found for the 5-nm-sized particles, being the smallest ones in this study. Their toxicity was even higher than that of silver ions at the same silver concentration. When compared as a function of the Ag⁺ concentration in equilibrium with 5-nm particles, the toxicity of ions was at least 17 times higher than that obtained by dissolving silver nitrite (if not taking into account the effect of nanoparticles themselves). The mechanism of the toxicity of silver nanoparticles was found complex with an important role played by the adsorption of silver nanoparticles and the ions released from the particles on the cell surface. This mechanism could be described as some sort of synergy between nanoparticles and ions. While our study clearly showed the presence of this synergy, its detailed explanation is experimentally highly demanding, requiring a close cooperation between materials scientists, physical chemists, and biologists.     

How the tapeworm <Emphasis Type="Italic">Hymenolepis diminuta</Emphasis> affects zinc and cadmium accumulation in a host fed a hyperaccumulating plant (<Emphasis Type="Italic">Arabidopsis halleri</Emphasis>)

The effects of plant-bound zinc (Zn) and cadmium (Cd) on element uptake and their interactions in a parasite-host system were investigated in a model experiment. Male Wistar rats were divided into four groups (C, P, TC and TP). Groups TC and TP were infected with the rat tapeworm Hymenolepis diminuta. Groups C and TC were fed a standard rodent mixture (ST-1) and received 10.5 mg of Zn per week, while groups P and TP were fed a mixture supplemented with the Zn- and Cd-hyperaccumulating plant Arabidopsis halleri at a dosage of 236 mg Zn/week and 3.0 mg Cd/week. Rats were euthanized after 6 weeks, and Cd and Zn levels were determined in rat and tapeworm tissue. The results indicate that tapeworm presence did have an effect on Cd and Zn concentrations in the host tissue; the majority of tissues in infected rats had statistically significant lower Zn and Cd concentrations than did uninfected rats. Tapeworms accumulated more zinc and cadmium than did the majority of host tissues. This important finding confirms the ability of tapeworms to accumulate certain elements (heavy metals) from the host body to their own body tissues. Thus, tapeworms can decrease heavy metal concentrations in host tissues.     

Antioxidant defense gene analysis in <Emphasis Type="Italic">Brassica oleracea</Emphasis> and <Emphasis Type="Italic">Trifolium repens</Emphasis> exposed to Cd and/or Pb

This study focused on the expression analysis of antioxidant defense genes in Brassica oleracea and in Trifolium repens. Plants were exposed for 3, 10, and 56 days in microcosms to a field-collected suburban soil spiked by low concentrations of cadmium and/or lead. In both species, metal accumulations and expression levels of genes encoding proteins involved and/or related to antioxidant defense systems (glutathione transferases, peroxidases, catalases, metallothioneins) were quantified in leaves in order to better understand the detoxification processes involved following exposure to metals. It appeared that strongest gene expression variations in T. repens were observed when plants are exposed to Cd (metallothionein and ascorbate peroxidase upregulations) whereas strongest variations in B. oleracea were observed in case of Cd/Pb co-exposures (metallothionein, glutathione transferase, and peroxidase upregulations). Results also suggest that there is a benefit to use complementary species in order to better apprehend the biological effects in ecotoxicology.     

<Emphasis Type="Italic">Cryptosporidium</Emphasis> and cryptosporidiosis: the African perspective

The present overview discusses the findings of cryptosporidiosis research conducted in Africa and highlights the currently available information on Cryptosporidium epidemiology, genetic diversity, and distribution on the African continent, particularly among vulnerable populations, including children. It also emphasizes the burden of cryptosporidiosis, which is underestimated due to the presence of many silent asymptomatic carriers.Cryptosporidiosis is recognized as one of the leading causes of childhood diarrhea in African countries. It has dramatic adverse effects on child growth and development and causes increased mortality on a continent where HIV, poverty, and lack of sanitation and infrastructure increase the risk of cryptosporidial waterborne infection.     

<Emphasis Type="Italic">Mesorhizobium</Emphasis> bacterial strains isolated from the legume <Emphasis Type="Italic">Lotus corniculatus</Emphasis> are an alternative source for the production of polyhydroxyalkanoates (PHAs) to obtain bioplastics

Polyhydroxyalkanoic acids (PHAs) are natural polyesters that can be used to produce bioplastics which are biodegradable. Numerous microorganisms accumulate PHAs as energy reserves. Combinations of different PHAs monomers lead to the production of bioplastics with very different properties. In the present work, we show the capability of strains belonging to various phylogenetic lineages within the genus Mesorhizobium, isolated from Lotus corniculatus nodules, to produce different PHA monomers. Among our strains, we found the production of 3-hydroxybutyrate, 3-hydroxyvalerate, 3-hydroxydodecanoate, and 3-hydroxyhexadecanoate. Most of the PHA-positive strains were phylogenetically related to the species M. jarvisii. However, our findings suggest that the ability to produce different monomers forming PHAs is strain-dependent.     

Remediation potential of caffeine,oxybenzone, and triclosan by the salt marsh plants <Emphasis Type="Italic">Spartina maritima</Emphasis> and <Emphasis Type="Italic">Halimione portulacoides</Emphasis>

Pharmaceuticals and personal care products (PPCPs) have attracted increasing concern during the last decade because of their widespread uses and continuous release to the aquatic environment. This work aimed to study the distribution of caffeine (CAF), oxybenzone (MBPh), and triclosan (TCS) when they arrive in salt marsh areas and to assess their remediation potential by two different species of salt marsh plants: Spartina maritima and Halimione portulacoides. Experiments were carried out in the laboratory either in hydroponics (sediment elutriate) or in sediment soaked in elutriate, for 10 days. Controls without plants were also carried out. CAF, MBPh, and TCS were added to the media. In unvegetated sediment soaked in elutriate, CAF was mainly in the liquid phase (83%), whereas MBPh and TCS were in the solid phase (90% and 56%, respectively); the highest remediation was achieved for TCS (40%) and mainly attributed to bioremediation. The presence of plants in sediment soaked in elutriate-enhanced PPCPs remediation, decreasing CAF and TCS levels between approximately 20-30% and MBPh by 40%.. Plant uptake, adsorption to plant roots/sediments, and bio/rhizoremediation are strong hypothesis to explain the decrease of contaminants either in water or sediment fractions, according to PPCPs characteristics.     

Enzymatic basis for fungicide removal by <Emphasis Type="Italic">Elodea canadensis</Emphasis>

Purpose  

Plants can absorb a diversity of natural and man-made toxic compounds for which they have developed diverse detoxification mechanisms. Plants are able to metabolize and detoxify a wide array of xenobiotics by oxidation, sugar conjugation, glutathione conjugation, and more complex reactions. In this study, detoxification mechanisms of dimethomorph, a fungicide currently found in aquatic media were investigated in Elodea canadensis.