16 research outputs found

    Immobilization of the white-rot fungus Anthracophyllum discolor to degrade the herbicide atrazine

    Get PDF
    Herbicides cause environmental concerns because they are toxic and accumulate in the environment, food products and water supplies. There is a need to develop safe, efficient and economical methods to remove them from the environment, often by biodegradation. Atrazine is such herbicide. White-rot fungi have the ability to degrade herbicides of potential utility. This study formulated a novel pelletized support to immobilize the white-rot fungus Anthracophyllum discolor to improve its capability to degrade the atrazine using a biopurification system (BS). Different proportions of sawdust, starch, corn meal and flaxseed were used to generate three pelletized supports (F1, F2 and F3). In addition, immobilization with coated and uncoated pelletized supports (CPS and UPS, respectively) was assessed. UPS-F1 was determined as the most effective system as it provided high level of manganese peroxidase activity and fungal viability. The half-life (t1/2) of atrazine decreased from 14 to 6 days for the control and inoculated samples respectively. Inoculation with immobilized A. discolor produced an increase in the fungal taxa assessed by DGGE and on phenoloxidase activity determined. The treatment improves atrazine degradation and reduces migration to surface and groundwater.Grant CONICYT/FONDAP/15130015Grant FONDECYT 112096

    TFOS Lifestyle: Impact of nutrition on the ocular surface: TFOS Lifestyle Workshop: Nutrition report

    Full text link
    Nutrients, required by human bodies to perform life-sustaining functions, are obtained from the diet. They are broadly classified into macronutrients (carbohydrates, lipids, and proteins), micronutrients (vitamins and minerals) and water. All nutrients serve as a source of energy, provide structural support to the body and/or regulate the chemical processes of the body. Food and drinks also consist of non-nutrients that may be beneficial (e.g., antioxidants) or harmful (e.g., dyes or preservatives added to processed foods) to the body and the ocular surface. There is also a complex interplay between systemic disorders and an individual's nutritional status. Changes in the gut microbiome may lead to alterations at the ocular surface. Poor nutrition may exacerbate select systemic conditions. Similarly, certain systemic conditions may affect the uptake, processing and distribution of nutrients by the body. These disorders may lead to deficiencies in micro- and macro-nutrients that are important in maintaining ocular surface health. Medications used to treat these conditions may also cause ocular surface changes. The prevalence of nutrition-related chronic diseases is climbing worldwide. This report sought to review the evidence supporting the impact of nutrition on the ocular surface, either directly or as a consequence of the chronic diseases that result. To address a key question, a systematic review investigated the effects of intentional food restriction on ocular surface health; of the 25 included studies, most investigated Ramadan fasting (56%), followed by bariatric surgery (16%), anorexia nervosa (16%), but none were judged to be of high quality, with no randomized-controlled trials

    TFOS European Ambassador meeting: Unmet needs and future scientific and clinical solutions for ocular surface diseases

    Full text link
    The mission of the Tear Film & Ocular Surface Society (TFOS) is to advance the research, literacy, and educational aspects of the scientific field of the tear film and ocular surface. Fundamental to fulfilling this mission is the TFOS Global Ambassador program. TFOS Ambassadors are dynamic and proactive experts, who help promote TFOS initiatives, such as presenting the conclusions and recommendations of the recent TFOS DEWS II™, throughout the world. They also identify unmet needs, and propose future clinical and scientific solutions, for management of ocular surface diseases in their countries. This meeting report addresses such needs and solutions for 25 European countries, as detailed in the TFOS European Ambassador meeting in Rome, Italy, in September 2019

    Degradation of isoproturon and bentazon in peat- and compost- based biomixtures

    No full text
    BACKGROUND: The composition and properties of a biomixture used in a biobed are decisive for pesticide sorption and degradation. This study was performed to investigate the capability of compost-based substrates in mixtures with citrus peel and vine branch straw and peat-based substrates in mixtures with soil and vine branch straw at different levels in order to degrade isoproturon and bentazone. RESULTS: Dissipation and mineralisation rates of both pesticides were determined, and metabolic activity was followed as respiration. Compost-based substrates showed faster pesticide dissipation in the presence of lignocellulosic materials, as in garden compost and vine branch straw. The increasing content of vine branch straw in peat-based substrates does not seem to affect dissipation of the parent compounds. Low mineralisation rate was observed in all treatments. CONCLUSION: Higher pesticide degradation was observed in the lignocellulosic substrates, probably because of the development of lignin-degrading microorganisms which have shown to be robust and are able to degrade recalcitrant pesticides

    Microbial impact of the pesticide chlorpyrifos on Swedish and Italian biobeds

    No full text
    Biobeds provide a simple and cheap solution to reducing point-source contamination by pesticides from farm activities. In its original design, the Swedish biobed is a clay-lined pit in the ground \ufb01lled with a biomixture of topsoil, peat and straw and covered with a grass layer. The straw stimulates the growth of lignin-degrading fungi and the formation and activity of ligninolytic enzymes which can degrade many di\ufb00erent pesticides. Here we compared the behaviour of the chlorpyrifos pesticide in two biobeds of di\ufb00erent composition: a Swedish biobed composed of 50%v vine straw, 25%v peat and 25%v Swedish soil; and an Italian biobed composed of 40%v vine straw, 40%v green compost and 20%v Italian soil. Microbial biomass was measured in the Italian biomix by the fumigation-extraction method. The microbial activity was estimated by measuring mineralisation of a synthetic lignin, 14 C-de-hydrogenative polymerisate (14 C-DHP) in the Swedish biomix. Microbial respiration was followed over time in both biomixes. Our results show that the chlorpyrifos half-lives were similar in both biomixes. The microbial biomass content was reduced by 25 and 50% with, respectively, 10 and 50 mg kg 121 chlorpyrifos in the Italian biomix. The respiration activity was a\ufb00ected only at 50 mg kg 121 chlorpyrifos in the Italian biomix. No e\ufb00ect was observed in the Swedish biomix despite the higher chlorpyrifos concentration of 100 mg kg 121 . The mineralisation of 14 C-DHP was not a\ufb00ected by the presence of chlorpyrifos in the Swedish biomix. These \ufb01ndings could be explained by the presence of chlorpyrifos-sensitive microorganisms in the Italian biomix and chlorpyrifos- resitant microorganisms in the Swedish biomix. The more robust micro\ufb02ora developed in the Swedish biomix may be explained by its lower nitrogen content, higher C/N ratio and lower pH, all of which are favourable for the development of lignin-degrading fungi and their activity. In Sweden more than 1000 biobeds are in practical use on farms and they have been shown to be e\ufb03cient at reducing pesticide water-body contamination. The present study compares the capability of an Italian biomix for degrading pesticides to that shown by the Swedish original biomix in order to introduce this biological system for a sustainable Italian agriculture

    On-farm biopurification systems for the depuration of pesticide wastewaters: recent biotechnological advances and future perspectives

    No full text
    Point source contamination of natural water resources by pesticides constitutes a serious problem and on-farm biopurification systems (BPS) were introduced to resolve it. This paper reviews the processes and parameters controlling BPS depuration efficiency and reports on recent biotechnological advances which have been used for enhancing BPS performance. Biomixture composition and water management are the two factors which either individually or through their interactions control the depuration performance of BPS. Which process (biodegradation or adsorption) will dominate pesticides dissipation in BPS depends on biomixture composition and the physicochemical properties of the pesticides. Biotechnological interventions such as augmentation with pesticide-degrading microbes or pesticide-primed matrices have resulted in enhanced biodegradation performance of BPS. Despite all these advancement in BPS research, there are still several issues which should be resolved to facilitate their full implementation. Safe handling and disposal of the spent biomixture is a key practical issue which needs further research. The use of BPS for the depuration of wastewaters from post-farm activities such as postharvest treatment of fruits should be a priority research issue considering the lack of alternative treatment systems. However, the key point hampering optimization of BPS is the lack of fundamental knowledge on BPS microbiology. The use of advanced molecular and biochemical methods in BPS would shed light into this issue in the future

    Mitigation Measures for Water Pollution and Flooding

    No full text
    This chapter discusses the range of measures that can be used to mitigate the impacts of water pollution and flooding. It makes a distinction between source measures which aim to reduce the amount of water or pollutant initially mobilised, pathway interventions which seek to slow the flow of pollutant enriched water once it has become mobilised and methods to protect receptor water bodies which are intended to reduce peak flows or prevent pollutants moving further through a catchment. In many European countries the policies and programmes used to increase the adoption of such measures are heavily influenced by EU obligations stemming from the Floods, Nitrates and Water Framework Directives. Typical approaches used involve a combination of regulation, financial incentives and advice provision. There are also a range of tools that can be used to model the potential effects of mitigation measures and a number of research programmes generating findings that may be of value to the landscape planner

    Application of a biosorbent to soil: a potential method for controlling water pollution by pesticides

    No full text
    Different strategies are now being optimized to prevent water from agricultural areas being contaminated by pesticides. The aim of this work was to optimize the adsorption of non-polar (tebuconazole, triadimenol) and polar (cymoxanil, pirimicarb) pesticides by soils after applying the biosorbent spent mushroom substrate (SMS) at different rates. The adsorption isotherms of pesticides by three soils and SMS-amended soils were obtained and the adsorption constants were calculated. The distribution coefficients (Kd) increased 1.4023.1 times (tebuconazole), 1.0823.7 times (triadimenol), 1.3142.1 times (cymoxanil), and 0.5523.8 times (pirimicarb) for soils amended with biosorbent at rates between 2 and 75 %. Increasing the SMS rates led to a constant increase in adsorption efficiency for non-polar pesticides but not for polar pesticides, due to the increase in the organic carbon (OC) content of soils as indicated by KOC values. The OC content of SMS-amended soils accounted for more than 90 % of the adsorption variability of non-polar pesticides, but it accounted for only 56.3 % for polar pesticides. The estimated adsorption of SMS-amended soils determined from the individual adsorption of soils and SMS was more consistent with real experimental values for non-polar pesticides than for polar pesticides. The results revealed the use of SMS as a tool to optimize pesticide adsorption by soils in dealing with specific contamination problems involving these compounds. © 2016, Springer-Verlag Berlin Heidelberg
    corecore