Effect of Water Activity and Temperature on Aflatoxin Production by Aspergillus parasiticus

The effect of water activity (aw) on growth and aflatoxin production by Aspergillus parasiticus NRRL 2999 was determined using submerged cultures in which the aw was adjusted by addition of glycerine, glucose, or a mixture of salts. At a sub-optimal aw aflatoxin production was low in the glycerol and glucose media while no strong inhibition of mycelial growth occurred. A similar effect was obtained in surface cultures on agar media in which the aw was adjusted by addition of glycerine or sucrose. The effect of a sub-optimal temperature was the reverse; compared to inhibition of mycelial growth in surface cultures, the effect on aflatoxin production was slight. No detectable quantities of aflatoxin B1 were formed at 0.83 aw and at 10 C nor at four combinations of higher aw and temperature. The aw was measured by a recently developed device using the dewpoint principle.</jats:p

Towards sustainable land management in the drylands: Scientific connections in monitoring and assessing dryland degradation, climate change and biodiversity

The United Nations Convention to Combat Desertification and its sister conventions, the United Nations Framework Convention on Climate Change and the Convention on Biological Diversity, all aim to halt or mitigate the deterioration of the ecological processes on which life depends. Sustainable land management (SLM) is fundamental to achieving the goals of all three Conventions. Changes in land management undertaken to address dryland degradation and desertification can simultaneously reduce net greenhouse gas emissions and contribute to conservation of biodiversity. Management to protect and enhance terrestrial carbon stocks, both in vegetation and soil, is of central importance to all three conventions. Protection of biodiversity conveys stability and resilience to agro-ecosystems and increases carbon storage potential of dryland systems. SLM improves livelihoods of communities dependent on the land. Despite these complementarities between the three environmental goals, tradeoffs often arise in their pursuit. The importance of human-environment interactions to the condition of land compels attention to adaptive management. In order to reconcile concerns and agendas at a higher strategic level, identification of synergies, conflicts, trade-offs, interconnections, feedbacks and spillover effects among multiple objectives, drivers, actions, policies and time horizons are crucial. Once these issues are transparent, coordinated action can be put into place across the three multilateral environmental agreements in the development of strategies and policy measures to support SLM

Towards sustainable land management in the drylands: Scientific connections in monitoring and assessing dryland degradation, climate change and biodiversity

The United Nations Convention to Combat Desertification and its sister conventions, the United Nations Framework Convention on Climate Change and the Convention on Biological Diversity, all aim to halt or mitigate the deterioration of the ecological processes on which life depends. Sustainable land management (SLM) is fundamental to achieving the goals of all three Conventions. Changes in land management undertaken to address dryland degradation and desertification can simultaneously reduce net greenhouse gas emissions and contribute to conservation of biodiversity. Management to protect and enhance terrestrial carbon stocks, both in vegetation and soil, is of central importance to all three conventions. Protection of biodiversity conveys stability and resilience to agro-ecosystems and increases carbon storage potential of dryland systems. SLM improves livelihoods of communities dependent on the land. Despite these complementarities between the three environmental goals, tradeoffs often arise in their pursuit. The importance of human-environment interactions to the condition of land compels attention to adaptive management. In order to reconcile concerns and agendas at a higher strategic level, identification of synergies, conflicts, trade-offs, interconnections, feedbacks and spillover effects among multiple objectives, drivers, actions, policies and time horizons are crucial. Once these issues are transparent, coordinated action can be put into place across the three multilateral environmental agreements in the development of strategies and policy measures to support SLM. Copyright C 2011 John Wiley & Sons, Ltd

Determination and Confirmation of Identity of Aflatoxin M1 in Dairy Products: Collaborative Study

Abstract An international collaborative study involving 23 collaborators was conducted to test methods, improved over previous methods with respect to speed and solvent use, for the rapid determination and thin layer chromatographic (TLC) confirmation of aflatoxin M1 identity in dairy products. For the quantitative method, collaborators assayed samples of Couda and cheddar cheeses, powdered milk, and butter containing levels of M1 near the anticipated limit of determination. Statistical analysis of the study results indicated that the lower limit of determination and precision of this method were comparable to these parameters of methods previously approved for analysis for aflatoxin M1. A few collaborators found that M1 eluted early from cleanup columns with cheese and butter samples and that emulsions formed during powdered milk sample extraction. The reasons for these problems have been determined and remedies are provided. For the TLC confirmation of identity method, collaborators prepared trifluoroacetic acid derivatives of M1 on the plates after 2-dimensional development. Concentrations as low as 0.3 ng/g cheese and 1.0 ng/g powdered milk were determined in this study. As a result of this study, both methods have been adopted as official first action methods by the AOAC and as reference methods by IUPAC.</jats:p