94 research outputs found

    Zearalenone production and growth in drinking water inoculated with Fusarium graminearum

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    Production of the mycotoxin zearalenone (ZEN) was examined in drinking water inoculated with Fusarium graminearum. The strain employed was isolated from a US water distribution system. ZEN was purified with an immunoaffinity column and quantified by high-performance liquid chromatography (HPLC) with fluorescence detection. The extracellular yield of ZEN was 15.0 ng l−1. Visual growth was observed. Ergosterol was also indicative of growth and an average of 6.2 μg l−1 was obtained. Other compounds were also detected although remain unidentified. There is no equivalent information available. More work is required on metabolite expression in water as mycotoxins have consequences for human and animal health. The levels detected in this study were low. Water needs to be accepted as a potential source as it attracts high quality demands in terms of purity.Fundação para a Ciência e a Tecnologia (FCT

    Biochemical mutagens affect the preservation of fungi and biodiversity estimations

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    Many fungi have significant industrial applications or biosafety concerns and maintaining the original characteristics is essential. The preserved fungi have to represent the situation in nature for posterity, biodiversity estimations, and taxonomic research. However, spontaneous fungal mutations and secondary metabolites affecting producing fungi are well known. There is increasing interest in the preservation of microbes in Biological Resource Centers (BRC) to ensure that the organisms remain viable and stable genetically. It would be anathema if they contacted mutagens routinely. However, for the purpose of this discussion, there are three potential sources of biochemical mutagens when obtaining individual fungi from the environment: (a) mixtures of microorganisms are plated routinely onto growth media containing mutagenic antibiotics to control overgrowth by contaminants, (b) the microbial mixtures may contain microorganisms capable of producing mutagenic secondary metabolites, and (c) target fungi for isolation may produce “self” mutagens in pure culture. The probability that these compounds could interact with fungi undermines confidence in the preservation process and the potential effects of these biochemical mutagens are considered for the first time on strains held in BRC in this review

    Future scenarios for oil palm mortality and infection by Phytophthora palmivora in Colombia, Ecuador and Brazil, extrapolated to Malaysia and Indonesia

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    Palm oil is a very important commodity especially to Malaysia and Indonesia. However, Latin American countries have significant industries, particularly Colombia. Climate change (CC) is a highly probable phenomenon which will affect diseases of oil palm (OP) with Phytophthora palmivora causing devastating outbreaks in Latin America and especially Colombia. Furthermore, the oomycete is an endemic pathogen to other crops in Malaysia such as durian, and is capable of causing disease of OP in vitro. A similar disease has been recorded in Thailand. It is crucial that P. palmivora is controlled in Malaysia and Indonesia because the organism is highly virulent, although there are acute and chronic forms. This current paper investigates the effect of CC on P. palmivora disease and on OP survival via a CLIMEX model for future suitable growth of OP. Postulated schemes are provided for Malaysia and Indonesia for acute and chronic forms of the disease which indicate an extremely high and increasing threat, likely to reduce the sustainability of the OP industry by 2050 and further by 2070 and/or 2100. Brazil appears less threatened by the disease under these scenarios, but their OP is likely to have 100% mortality. The chronic and acute forms of the malady present reduced and high threats respectively to Malaysia and Indonesia. The data herein will be useful for, inter alia, plantation managers who will be able to assess the accuracy of these scenarios in the future. Amelioration methods are required urgently and quarantine procedures need strengthening.(undefined)info:eu-repo/semantics/publishedVersio

    Longitudinal trends of future climate change and oil palm growth: empirical evidence for tropical Africa

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    Palms are highly significant tropical plants. Oil palms produce palm oil, the basic commodity of a highly important industry. Climate change from greenhouse gasses is likely to decrease the ability of palms to survive, irrespective of them providing ecosystem services to communities. Little information about species survival in tropical regions under climate change is available and data on species migration under climate change is important. Palms are particularly significant in Africa: a palm oil industry already exists with Nigeria being the largest producer. Previous work using CLIMEX modelling indicated that Africa will have reduced suitable climate for oil palm in Africa. The current paper employs this modelling to assess how suitable climate for growing oil palm changed in Africa from current time to 2100. An increasing trend in suitable climate from west to east was observed indicating that refuges could be obtained along the African tropical belt. Most countries had reduced suitable climates but others had increased, with Uganda being particularly high. There may be a case for developing future oil palm plantations towards the east of Africa. The information may be usefully applied to other palms. However, it is crucial that any developments will fully adhere to environmental regulations. Future climate change will have severe consequences to oil palm cultivation but there may be scope for eastwards mitigation in Africa.info:eu-repo/semantics/publishedVersio

    Future climate effects on suitability for growth of oil palms in Malaysia and Indonesia

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    The production of palm oil (PO) is highly profitable. The economies of the principal producers, Malaysia and Indonesia, and others, benefit considerably. Climate change (CC) will most likely have an impact on the distribution of oil palms (OP) (Elaeis guineensis). Here we present modelled CC projections with respect to the suitability of growing OP, in Malaysia and Indonesia. A process-oriented niche model of OP was developed using CLIMEX to estimate its potential distribution under current and future climate scenarios. Two Global Climate Models (GCMs), CSIRO-Mk3.0 and MIROC-H, were used to explore the impacts of CC under the A1B and A2 scenarios for 2030, 2070 and 2100. Decreases in climatic suitability for OP in the region were gradual by 2030 but became more pronounced by 2100. These projections imply that OP growth will be affected severely by CC, with obvious implications to the economies of (a) Indonesia and Malaysia and (b) the PO industry, but with potential benefits towards reducing CC. A possible remedial action is to concentrate research on development of new varieties of OP that are less vulnerable to CC.The Portuguese-based authors thank the FCT Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the Project "BioEnv - Biotechnology and Bioengineering for a sustainable world", REF. NORTE-07-0124-FEDER-000048, co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER

    Synergies for Improving Oil Palm Production and Forest Conservation in Floodplain Landscapes

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    Lowland tropical forests are increasingly threatened with conversion to oil palm as global demand and high profit drives crop expansion throughout the world’s tropical regions. Yet, landscapes are not homogeneous and regional constraints dictate land suitability for this crop. We conducted a regional study to investigate spatial and economic components of forest conversion to oil palm within a tropical floodplain in the Lower Kinabatangan, Sabah, Malaysian Borneo. The Kinabatangan ecosystem harbours significant biodiversity with globally threatened species but has suffered forest loss and fragmentation. We mapped the oil palm and forested landscapes (using object-based-image analysis, classification and regression tree analysis and on-screen digitising of high-resolution imagery) and undertook economic modelling. Within the study region (520,269 ha), 250,617 ha is cultivated with oil palm with 77% having high Net-Present-Value (NPV) estimates (413/ha?yr413/ha?yr–637/ha?yr); but 20.5% is under-producing. In fact 6.3% (15,810 ha) of oil palm is commercially redundant (with negative NPV of 299/ha?yr-299/ha?yr--65/ha?yr) due to palm mortality from flood inundation. These areas would have been important riparian or flooded forest types. Moreover, 30,173 ha of unprotected forest remain and despite its value for connectivity and biodiversity 64% is allocated for future oil palm. However, we estimate that at minimum 54% of these forests are unsuitable for this crop due to inundation events. If conversion to oil palm occurs, we predict a further 16,207 ha will become commercially redundant. This means that over 32,000 ha of forest within the floodplain would have been converted for little or no financial gain yet with significant cost to the ecosystem. Our findings have globally relevant implications for similar floodplain landscapes undergoing forest transformation to agriculture such as oil palm. Understanding landscape level constraints to this crop, and transferring these into policy and practice, may provide conservation and economic opportunities within these seemingly high opportunity cost landscapes

    Impacts of climate change on plant diseases – opinions and trends

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    There has been a remarkable scientific output on the topic of how climate change is likely to affect plant diseases in the coming decades. This review addresses the need for review of this burgeoning literature by summarizing opinions of previous reviews and trends in recent studies on the impacts of climate change on plant health. Sudden Oak Death is used as an introductory case study: Californian forests could become even more susceptible to this emerging plant disease, if spring precipitations will be accompanied by warmer temperatures, although climate shifts may also affect the current synchronicity between host cambium activity and pathogen colonization rate. A summary of observed and predicted climate changes, as well as of direct effects of climate change on pathosystems, is provided. Prediction and management of climate change effects on plant health are complicated by indirect effects and the interactions with global change drivers. Uncertainty in models of plant disease development under climate change calls for a diversity of management strategies, from more participatory approaches to interdisciplinary science. Involvement of stakeholders and scientists from outside plant pathology shows the importance of trade-offs, for example in the land-sharing vs. sparing debate. Further research is needed on climate change and plant health in mountain, boreal, Mediterranean and tropical regions, with multiple climate change factors and scenarios (including our responses to it, e.g. the assisted migration of plants), in relation to endophytes, viruses and mycorrhiza, using long-term and large-scale datasets and considering various plant disease control methods

    Comparison of sterols and fatty acids in two species of Ganoderma

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    <p>Abstract</p> <p>Background</p> <p>Two species of <it>Ganoderma, G. sinense </it>and <it>G. lucidum</it>, are used as <it>Lingzhi </it>in China. Howerver, the content of triterpenoids and polysaccharides, main actives compounds, are significant different, though the extracts of both <it>G. lucidum </it>and <it>G. sinense </it>have antitumoral proliferation effect. It is suspected that other compounds contribute to their antitumoral activity. Sterols and fatty acids have obvious bioactivity. Therefore, determination and comparison of sterols and fatty acids is helpful to elucidate the active components of <it>Lingzhi</it>.</p> <p>Results</p> <p>Ergosterol, a specific component of fungal cell membrane, was rich in <it>G. lucidum </it>and <it>G. sinense</it>. But its content in <it>G. lucidum </it>(median content 705.0 μg·g<sup>-1</sup>, range 189.1-1453.3 μg·g<sup>-1</sup>, n = 19) was much higher than that in <it>G. sinense </it>(median content 80.1 μg·g<sup>-1</sup>, range 16.0-409.8 μg·g<sup>-1</sup>, n = 13). Hierarchical clustering analysis based on the content of ergosterol showed that 32 tested samples of <it>Ganoderma </it>were grouped into two main clusters, <it>G. lucidum </it>and <it>G. sinense</it>. Hierarchical clustering analysis based on the contents of ten fatty acids showed that two species of <it>Ganoderma </it>had no significant difference though two groups were also obtained. The similarity of two species of <it>Ganoderma </it>in fatty acids may be related to their antitumoral proliferation effect.</p> <p>Conclusions</p> <p>The content of ergosterol is much higher in <it>G. lucidum </it>than in <it>G. sinense</it>. Palmitic acid, linoleic acid, oleic acid, stearic acid are main fatty acids in <it>Ganoderma </it>and their content had no significant difference between <it>G. lucidum </it>and <it>G. sinense</it>, which may contribute to their antitumoral proliferation effect.</p
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