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Biodegradation of aliphatic hydrocarbons in the presence of hydroxy cucurbit[6]uril
2014
Pasumarthi, Rajesh | Kumar, Vikash | Chandrasekharan, Sivaraman | Ganguly, Anasuya | Banerjee, Mainak | Mutnuri, Srikanth
Aliphatic hydrocarbons are one of the major environmental pollutants with reduced bioavailability. The present study focuses on the effect of hydroxy cucurbit[6]uril on the bioavailability of hydrocarbons. A bacterial consortium was used for biodegradation studies under saline and non-saline conditions. Based on denaturing gradient gel electrophoresis results it was found that the consortium under saline conditions had two different strains. The experiment was conducted in microcosms with tetradecane, hexadecane, octadecane and mixture of the mentioned hydrocarbons as the sole carbon source. The residual hydrocarbon was quantified using gas chromatography every 24h. It was found that biodegradation of tetradecane and hexadecane, as individual carbon source increased in the presence of hydroxy CB[6], probably due to the increase in their bioavailability. In case of octadecane this did not happen. Bioavailability of all three aliphatic hydrocarbons was increased when provided as a mixture to the consortium under saline conditions.
Afficher plus [+] Moins [-]A novel best practices approach: The MARLISCO case
2014
Loizidou, Xenia I. | Loizides, Michael I. | Orthodoxou, Demetra L.
Research that was undertaken to identify and evaluate best practices that can effectively minimise the amount of marine litter in European Seas is presented. Best practices were approached in a novel way that aimed to maximise the impact and added value of the FP7-funded project MARLISCO. The practices served as a tool to enhance the active participation and build capacity in key actors through the implementation of the innovative, dedicatedly-developed decision support tool, DeCyDe-4-Marlisco.This paper also presents the key ‘preference’ attributes of successful marine litter management practices and provides a snapshot of the key characteristics of the recorded best practices as a means of helping the reader, and particularly decision makers, recognise what would make their marine litter management efforts more successful.
Afficher plus [+] Moins [-]Lost opportunities: Coral recruitment does not translate to reef recovery in the Florida Keys
2014
van Woesik, Robert | Scott, William J. | Aronson, Richard B.
We tested the hypothesis that the poor recovery of the coral populations on reefs in the Florida Keys is related to low coral recruitment. In the summer of 2011, we deployed 240 terracotta tiles at eight study sites in a balanced design: (i) among three depths; and (ii) between fished and unfished reefs. Corals recruited to ∼40% of the deployed tiles, with more corals settling on tiles on unfished reefs than on fished reefs. The apparent effect of protection was not a consequence of different densities of herbivorous fishes, but was more likely related to local hydrography and the tendency of the no-take reserves to act as larval sinks, particularly in the lower Florida Keys. There was a mismatch between the coral taxa that recruited and the adult coral assemblages, suggesting that recruits were arriving but not surviving to contribute to coral recovery.
Afficher plus [+] Moins [-]Indole derivatives inhibited the formation of bacterial biofilm and modulated Ca2+ efflux in diatom
2014
Yang, Cuiyun | Yu, Yanan | Sun, Wenjun | Xia, Chuanhai
Marine biofouling is a serious environmental problem worldwide. As an effort to find environmental friendly antifoulants, indole derivatives were determined for their activities to inhibit the growth of bacteria and diatom. The minimum inhibitory concentrations (MICs) of indole derivatives against bacteria were very low, especially for 6-chloroindole. It was proved that 6-chloroindole obviously inhibited the growth of bacteria, interfered with the formation of bacterial biofilm, destroyed bacterial cell morphology and also inhibited the growth of diatom Cylindrotheca sp. as well. By using noninvasive micro-test technique (NMT), 6-chloroindole triggered algal cellular Ca2+ efflux. The highest value was 72.03pmolcm−2s−1, 10.6 times of the control group. The present studies indicated that indole derivatives might have the potential to be new antifouling agents because of their excellent antibacterial and anti-algal activities. At the same time, Ca2+ efflux might be one of the mechanisms that indole derivatives inhibited the growth of diatom.
Afficher plus [+] Moins [-]Biodegradation of nitrobenzene in a lysogeny broth medium by a novel halophilic bacterium Bacillus licheniformis
2014
Li, Tian | Deng, Xinping | Wang, Jinjun | Chen, Yucheng | He, Lin | Sun, Yuchuan | Song, Caixia | Zhou, Zhifeng
The Bacillus licheniformis strain YX2, a novel nitrobenzene-degrading halophilic bacterium, was isolated from active sludge obtained from a pesticide factory. Strain YX2 can withstand highly acidic and alkaline conditions and high temperatures. Degradation of nitrobenzene (200mgL−1) by YX2 exceeded 70% after 72h in lysogeny broth medium (pH 4–9). Under optimal degradation conditions (33°C, pH 7 in LB medium) YX2 degraded 50, 100, 200, and 600mgL−1 nitrobenzene within 36, 36, 72, and 156h, respectively. Even in the presence of benzene, phenol or aniline, strain YX2 efficiently degraded nitrobenzene. Furthermore, strain YX2 completely degraded 600mgL−1 nitrobenzene in 7% NaCl (w/w). Thus, our data show that strain YX2 may have promise for removing nitrobenzene from complex wastewaters with high salinity and variable pH.
Afficher plus [+] Moins [-]Human health risks in national capital territory of Delhi due to air pollution
2014
Nagpure, Ajay Singh | Gurjar, Bhola Ram | Martel, Jc
This study evaluates the human health risks in Indian National Capital Territory of Delhi (NCT Delhi) in terms of mortality and morbidity due to air pollution. The spreadsheet model, Risk of Mortality/Morbidity due to Air Pollution (Ri–MAP) was used to evaluate the direct health impacts of various criteria air pollutants present in various districts of NCT Delhi during the period 1991 to 2010. By adopting the World Health Organization (WHO) guideline concentrations for the air pollutants SO2, NO2 and total suspended particles (TSP), concentration–response relationships and a population attributable–risk proportion concept were employed. About 11 394, 3 912, 1 697 and 16 253 excess number of cases of total mortality, cardiovascular mortality, respiratory mortality and hospital admission of COPD respectively were observed for entire NCT Delhi in year 2000. However, within a one decade, in year 2010 these figures became 18 229, 6 374, 2 701 and 26 525. District–wise analysis shows that North West district is having the highest number of mortality and morbidity cases continuously after 2002, moreover least excess number of cases was observed for New Delhi district.
Afficher plus [+] Moins [-]Microphytobenthic response to mussel farm biodeposition in coastal sediments of the northern Adriatic Sea
2014
Franzo, Annalisa | Cibic, Tamara | Del Negro, Paola | Solidoro, Cosimo
The effects of long-line mussel farming on microphytobenthos were investigated in a coastal area of the Gulf of Trieste. Sediment grain-size, organic matter content, microalgal abundance and community structure were analysed in September 2008 and March 2009. Four areas were sampled: a twenty-year farm, a four-year farm, a disused farm and a reference site. Principal component analysis (PCA) highlighted a decreasing gradient of organic matter content from the twenty-year farm to the control. Mussel farming seemed to influence microphytobenthic abundance with higher densities in the oldest farm. Three genera were dominant; Navicula and Gyrosigma seemed to be stimulated by the organic load under the active farms while we infer that Nitzschia proliferation was limited by shade caused by mussel ropes. In the PCA, samplings of the disused farm were placed in-between the still active farms and the control, indicating the partial recovery occurred in this site.
Afficher plus [+] Moins [-]Mussels as a tool for mitigation of nutrients in the marine environment
2014
Petersen, Jens Kjerulf | Hasler, Berit | Timmermann, Karen | Nielsen, Pernille | Tørring, Ditte Bruunshøj | Larsen, Martin Mørk | Holmer, Marianne
Long-line mussel farming has been proposed as a mitigation tool for removal of excess nutrients in eutrophic coastal waters. A full-scale mussel farm optimized for cost efficient nutrient removal was established in the eutrophic Skive Fjord, Denmark where biological and economic parameters related to nutrient removal was monitored throughout a full production cycle (1yr). The results showed that it was possible to obtain a high area specific biomass of 60tWWha−1eqvivalent to a nitrogen and phosphorus removal of 0.6–0.9 and 0.03–0.04tha−1yr, respectively. The analysis of the costs related to establishment, maintenance and harvest revealed that mussel production optimized for mitigation can be carried out at a lower cost compared to mussel production for (human) consumption. The costs for nutrient removal was 14.8€kg−1N making mitigation mussel production a cost-efficient measure compared to the most expensive land-based measures.
Afficher plus [+] Moins [-]Distribution and recovery trajectory of Macondo (Mississippi Canyon 252) oil in Louisiana coastal wetlands
2014
Turner, R Eugene | Overton, Edward B. | Meyer, Buffy M. | Miles, M. Scott | McClenachan, Giovanna | Hooper-Bui, Linda | Engel, Annette Summers | Swenson, Erick M. | Lee, James M. | Milan, Charles S. | Gao, Heng
We measured the concentration of petroleum hydrocarbons in 405 wetland sediment samples immediately before the April 2010 Deepwater Horizon disaster led to their broad-scale oiling, and on nine trips afterwards. The average concentrations of alkanes and PAHs were 604 and 186 times the pre-spill baseline values, respectively. Oil was distributed with some attenuation up to 100m inland from the shoreline for alkanes, but increased for aromatics, and was not well-circumscribed by the rapid shoreline assessments (a.k.a. SCAT) of relative oiling. The concentrations of target alkanes and PAHs in June 2013 were about 1% and 5%, respectively, of the February 2011 concentrations, but remained at 3.7 and 33 times higher, respectively, than in May 2010. A recovery to baseline conditions suggests that the concentration of alkanes may be near baseline values by the end of 2015, but that it may take decades for the PAH concentrations to be that low.
Afficher plus [+] Moins [-]Direct evidence of histopathological impacts of wastewater discharge on resident Antarctic fish (Trematomus bernacchii) at Davis Station, East Antarctica
2014
Corbett, Patricia A. | King, Catherine K. | Stark, Jonathan S. | Mondon, Julie A.
During the 2009/2010 summer, a comprehensive environmental impact assessment (EIA) of the wastewater discharge at Davis Station, East Antarctica was completed. As part of this, histological alteration of gill and liver tissue in Antarctic Rock-cod (Trematomus bernacchii) from four sites along a spatial gradient from the wastewater outfall were assessed. All fish within 800m of the outfall exhibited significant histological changes in both tissues. Common pathologies observed in fish closest to the outfall include proliferation of epithelial cells with associated secondary lamellar fusion in the gills and multifocal granulomata with inflammation and necrosis as well as cysts in the liver. Fish from sites >800m from the outfall also exhibited alterations but to a lesser degree, with prevalence and severity decreasing with increasing distance from the outfall. This study highlights the value of histopathological investigations as part of EIAs and provides the first evidence of sub-lethal alteration associated with wastewater discharge in East Antarctica.
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