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Aberdeen, Saudi Arabia

Alexander I.J.,University of Aberdeen | Mwinyihija M.,Kenya Leather Development Council | Killham K.,Remedios Ltd
Journal of Environmental Sciences (China) | Year: 2012

Contamination of irrigation water represents a major constraint to Bangladesh agriculture, resulting in elevated levels in the terrestrial systems. Lux bacterial biosensor technology has previously been used to measure the toxicity of metals in various environmental matrices. While arbuscular mycorrhizal fungi have their most significant effect on phosphorus uptake, but showed alleviated metal toxicity to the host plant. The study examined the effects of arsenic and inoculation with an arbuscular mycorrhizal fungus, Glomus mosseae, on lentil (Lens culinaris L. cv. Titore). Plants were grown with and without arbuscular mycorrhizal inoculum for 9 weeks in a sand and terra-green mixture (50:50, V/V) and watered with five levels of arsenic (0, 1, 2, 5, 10 mg As/L arsenate). The results showed that arsenic addition above 1 mg/L significantly reduced percentage of mycorrhizal root infection. On further analysis a close relationship was established with the vegetative and reproductive properties of lentil (L. culinaris) plants compared to the percentage bioluminescence of the soil leachate. However, arbuscular mycorrhizal fungal inoculation reduced arsenic concentration in roots and shoots. Higher concentrations of arsenic (5, 10 mg As/L arsenate) reduced the mycorrhizal efficiency to increase phosphorus content and nitrogen fixation. Therefore, this study showed that increased concentration of arsenic in irrigation water had direct implications to the lentil (L. culinaris) plants overall performance. Moreover the use of bioassay demonstrated that mycorrhiza and clay particle reduced arsenic bioavailability in soil. © 2012 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences.

Ahmed F.R.S.,E 16 | Alexander I.J.,University of Aberdeen | Mwinyihija M.,Leather Development Council | Killham K.,Remedios Ltd
Water, Air, and Soil Pollution | Year: 2011

Arsenic (As)-contaminated irrigation water is responsible for high As levels in soils and crops in many parts of the world, particularly in the Bengal Delta, Bangladesh and West Bengal, India. While arbuscular mycorrhizal (AM) fungi markedly improve phosphorus (P) uptake, they can also alleviate metal toxicity. In this study, the effects of superphosphate and inoculation with the AM fungus Glomus mosseae on P and As uptake of lentil were investigated. Plant height, shoot dry weight, shoot/root P concentration, and shoot P content increased due to mycorrhizal inoculation. However, As concentration in roots/shoots and root As content were reduced, plant height, shoot dry weight, shoot/root P concentration/content, and root As concentration and content increased due to superphosphate application. Root P concentration decreased with increasing As concentration. It was apparent that As concentration and content in shoots/roots increased with increasing As concentration in irrigation water. Superphosphate interaction with G. mosseae reduced the role of mycorrhizal infection in terms of enhancing P nutrition and reducing uptake of potentially toxic As into plant parts. The role and relationship of mycorrhizal in respect of P nutrition and As remediation efficiency in plant parts was established. In conclusion, it was worth alluding to that lentil with AM fungal inoculation can reduce As uptake and improve P nutrition. However, in retrospect superphosphate increased P and As uptake and decreased the role of the mycorrhizal association. This resulted in stimulating increased P uptake while decreasing As uptake in lentil. © 2011 Springer Science+Business Media B.V.

Alhadrami H.A.,University of Aberdeen | Alhadrami H.A.,King Abdulaziz University | Paton G.I.,University of Aberdeen | Paton G.I.,Remedios Ltd
FEMS Microbiology Letters | Year: 2013

The environmental fate and potency of mutagenic compounds is of growing concern. This has necessitated the development and application of rapid assays to screen large numbers of samples for their genotoxic and carcinogenic effects. Despite the development of biosensors for genotoxicity assessment, these have not been calibrated against traditional microbial bioassays. In this study, assays using the SOS-lux-marked microbial biosensors Escherichia coli K12C600 and E. coli DPD1718 were refined and optimised to screen selected mutagenic chemicals. The response of the biosensors was compared with the mutagenic response of the traditional Salmonella mutagenicity assay. For the chemicals tested (acridine, B[a]A, B[a]P, chrysene, mitomycin C and sodium azide), E. coli DPD1718 was consistently more sensitive than E. coli K12C600. The biosensors were of comparable sensitivity to the Salmonella assay but were more rapid, reproducible and easier to measure. These data validate the adoption of optimised assays making use of microbial biosensors for routine screening of test chemicals. © 2013 Federation of European Microbiological Societies.

KILLHAM K.,Remedios Ltd
Journal of Agricultural Science | Year: 2010

SUMMARYThis review introduces the main concepts behind integrated soil management (ISM) and examines the ways in which it currently operates. It suggests the scope for future technological development. The review also highlights the potential of ISM to address the challenge of meeting the demands of the increasing world population, while maintaining sustainable agro-ecosystems, as judged from long-term soil fertility, environmental and socio-economic perspectives. Changes to policy, governance and funding worldwide will be needed to conserve and manage the soil resource, and to restore already degraded systems. Research should be prioritized to ensure continued delivery of new soil technologies. Such changes must engage all land-use stakeholders, must involve educational, training and extension programmes and must embrace the multidisciplinarity required for effective soil conservation and management.

Coulon F.,Cranfield University | Al Awadi M.,University of Aberdeen | Cowie W.,University of Aberdeen | Mardlin D.,University of Aberdeen | And 9 more authors.
Environmental Pollution | Year: 2010

A six month field scale study was carried out to compare windrow turning and biopile techniques for the remediation of soil contaminated with bunker C fuel oil. End-point clean-up targets were defined by human risk assessment and ecotoxicological hazard assessment approaches. Replicate windrows and biopiles were amended with either nutrients and inocula, nutrients alone or no amendment. In addition to fractionated hydrocarbon analysis, culturable microbial characterisation and soil ecotoxicological assays were performed. This particular soil, heavy in texture and historically contaminated with bunker fuel was more effectively remediated by windrowing, but coarser textures may be more amendable to biopiling. This trial reveals the benefit of developing risk and hazard based approaches in defining end-point bioremediation of heavy hydrocarbons when engineered biopile or windrow are proposed as treatment option. © 2010 Elsevier Ltd. All rights reserved.

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