Annals of Environmental Science A peer-reviewed, open access, international journal for the environmental sciences en-US (Elham Ghabbour and Geoffrey Davies) (Hillary Corbett) Wed, 20 Aug 2014 00:00:00 -0400 OJS 60 Alterations in the Biochemical Parameters of the African Catfish Clarias Gariepinus [Burchell] Exposed to Sublethal Concentrations of Lambda-Cyhalothrin <p>Pesticide contamination of water bodies is increasingly becoming a threat to aquatic life with its attendant public health implications. With this in mind, this study was undertaken with a view to evaluating the effect of chronic exposure to λ-cyhalothrin on some biochemical parameters (cholesterol, glycogen, glucose and protein) in the freshwater catfish <em>Clarias gariepinus</em>. The fingerlings were exposed to sublethal concentrations (0.0, 0.01 and 0.04 mg/L) of λ-cyhalothrin for 21 days in a static renewal bioassay system. The LC<sub>50</sub> value determined by probit analysis was 0.103 mg/L. The cholesterol concentration was significantly higher (P &lt; 0.05) in the treatment groups when compared with the control. The increase was both concentration and duration-dependent. The protein concentration in the λ-cyhalothrin-exposed fish was significantly lower than the control (p &lt; 0.05) except on day 7, when the serum protein level did not differ from the group exposed to 0.01 mg/L λ-cyhalothrin. Similarly, when compared with the control, the liver glycogen and serum glucose concentrations decreased significantly (p &lt; 0.05) with increasing λ-cyhalothrin test concentration and duration of exposure. The observed hypercholesterolemia with concomitant hypoglycemia and hypoprotenemia are indications of stress due to λ-cyhalothrin exposure.</p> <p>&nbsp;</p> <p><strong>Permanent URL: </strong><a href=""></a></p> Ndubuisi S. Oluah, Agatha C. Chineke ##submission.copyrightStatement## Sat, 01 Mar 2014 00:00:00 -0500 Bioremediation of Oil Spills: A Review of Challenges for Research Advancement <p>As the demand for liquid petroleum increases, the need for reliable and efficient oil spill clean-up techniques is inevitable. Bioremediation is considered one of the most sustainable clean-up techniques but the potential has not been fully exploited in the field because it is too slow to meet the immediate demands of the environment. This study reviews the challenges to managing oil spills in terrestrial and marine environments to identify areas that require further research. Current challenges associated with bioremediation of spilled petroleum include resistance of asphalthenes to biodegradation; delay of heavy or high molar mass polycyclic aromatic hydrocarbon (PAH) biodegradation, eutrophication caused by biostimulation, unsustainability of bioaugmentation in the field, poor bioavailability of spilled petroleum, inefficiency of biodegradation in anoxic environments and failure of successful bioremediation laboratory studies in the field. Recommendations offered include encouraging asphalthene biodegradation by combining heat application (80°C), biosurfactant (thermophilic emulsifier) and bioaugmentation (using a consortium containing <em>Bacillus lentus</em> and <em>Pleurotus tuberregium</em> as members) but as a temporary measure, adopting the use of "booms and skimmers" and "organic sorbents" for water and land clean-up, respectively. Heavy PAHs may be rapidly degraded by applying nutrients (biostimulation) and biosurfactants to sites that are oleophilic microbe-rich. Oleophilic nutrients may be the most effective strategy to reduce eutrophication in marine environments whilst on land, slow-release nutrient application or organic-inorganic nutrient rotation may help prevent soil hardening and infertility. The use of encapsulating agents and genetically-engineered microbes (GEMs) may increase the efficiency of bioaugmentation in the field, but temporarily, indigenous oleophilic microbes may be employed in the field. Poor bioavailability of crude oil may be eliminated by the use of biosurfactants. In terrestrial anoxic sites, bioslurping-biosparging technology could be used whilst the marine anoxic site requires more research on how to transport nutrients and biosurfactants to oleophilic anaerobes residing in the ocean beds. The involvement of both governmental and non-governmental environmental institutions in sponsoring field studies in order to improve the reliability of bioremediation research. Further studies to test the practicability and cost of these recommendations in the field are needed.</p><p><strong>Permanent URL: </strong><a href=""></a></p> Babajide Milton Macaulay, Deborah Rees ##submission.copyrightStatement## Tue, 08 Apr 2014 00:00:00 -0400 Impacts of Aluminium, Molybdenum, Vanadium, Zirconium, Tungsten and Gallium on the Growth and Enzyme Production of Ascomycetous and Basidiomycetous Fungi <p>Metals may influence fungi, which have a key role in global carbon recycling and are promising organisms for bioremediation. The oxidative non-specific enzyme laccase is essential in the fungal degradation of polluting compounds and therefore the impact of these metals on laccase should be known. To assess impacts of Al, Mo, V, Zr, W or Ga, the growth and production of oxidative enzymes of three basidiomycetous and two ascomycetous fungi were tested on indicator color plates. The plates contained ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and alternatively Al (20-100 mg kg<sup>-1</sup>), Ga (10-50 mg kg<sup>-1</sup>), Mo (10-50 mg kg<sup>-1</sup>), Zr (10-50 mg kg<sup>-1</sup>), W (10-50 mg kg<sup>-1</sup>), or V (5-20 mg kg<sup>-1</sup>). All tested basidiomycetes <em>Phlebia radiata</em>, <em>Pleurotus pulmonarius</em> and <em>Physisporinus rivulosus</em>, produced oxidative enzymes with Al, W, Ga, Zr, Mo and V and without added metals. Ascomycetes, an <em>Alternaria</em> sp. and a <em>Fusarium</em> sp., did not produce oxidative enzymes. The growth of <em>P. radiata</em>, <em>P. pulmonarius</em> and <em>P. rivulosus</em> was sensitive to Al, Mo and W and tolerant to Zr. The growth of <em>P. radiata</em> was sensitive to Ga. The growth of <em>P. rivulosus</em> was sensitive to V. The growth of <em>P. pulmonarius</em> was tolerant to V, Ga and Zr. The growth of both the ascomycetes <em>Alternaria sp.</em> and <em>Fusarium sp.</em> was sensitive to all six metals (Al, Mo, V, Zr, W, Ga). The basidiomycetous fungi were more tolerant than ascomycetous fungi to all tested metals, indicating that they are more suitable for bioremediation of harmful organic xenobiotics than the ascomycetous fungi in metal-contaminated soil.</p><p><strong>Permanent URL: </strong><a href=""></a></p> Beata Kluczek-Turpeinen, Jenny Holm, Annele Hatakka, Mika A. Kähkönen ##submission.copyrightStatement## Tue, 29 Apr 2014 00:00:00 -0400