Legislation in the Netherlands requires routine analysis of drinking water samples for cultivable Legionella species from high-priority installations. A field study was conducted to investigate the presence of Legionella species in thermostatic shower mixer taps. Water samples and the interior of ten thermostatic shower mixer taps were investigated for cultivable Legionella species. In seven cases, Legionella species was found in at least one of the samples. In four cases, Legionella species was detected in the biofilm on the thermostatic shower mixer taps interior, with the highest values on rubber parts, and in five cases in the cold supply water. These results show that thermostatic shower mixer taps can play a role in exceeding the threshold limit for cultivable Legionella species, but the cold supply water can also be responsible. Practical implications: This study showed that contamination of thermostatic shower mixer taps (TSMTs) with Legionella spp. was frequently observed in combination with contamination of the water system. Consequently, a combined focus is necessary to prevent the proliferation of cultivable Legionella spp. in TSMTs. In addition, the results also demonstrated that biofilms on rubbers inside the TSMT had high numbers of Legionella spp., probably because rubber contains relatively high concentrations of biodegradable substrates. Therefore, improvement of the rubber materials is necessary to reduce the proliferation of cultivable Legionella spp. in TSMTs.
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Thermal disinfection is probably the oldest water treatment method ever used. Similarly to other disinfection processes, it targets the inactivation of pathogenic (micro)organisms present in water, wastewater and other media. In this work, a pilot-scale continuous-flow thermal disinfection system was investigated using highly contaminated hospital wastewater as influent without any pre-treatment step for turbidity removal. The results proved that the tested system can be used with influent turbidity as high as 100 NTU and still provide up to log 8 microbial inactivation. Further results have shown energy consumption comparable to other commercially available thermal disinfection systems and relatively low influence on the investigated physical–chemical parameters.
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PowerPointpresentatie gebruikt op de 2e Kennisdeeldag ’Voedselbossen Zuidoost-Nederland’ in Maastricht op 11 december 2019.
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Dairy products are known for their relatively low impact on the environment per unit of nutritional value. The carbon footprint of cheese from the Netherlands has been reduced in recent years by minimizing energy and water consumption. However,there are other options for further improving the sustainability of cheese production. The dairy research team at Van Hall Larenstein University of Applied Sciences is revealing new possibilities.
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In een tijd waarin de wereld geconfronteerd wordt met een toenemende bevolking en de daaruit voortvloeiende behoefte aan voedsel, staat het lectoraat Eiwittransitie voor een uiterst relevante uitdaging. De groeiende vraag naar eiwitten en de noodzaak om onze consumptiegewoonten in balans te krijgen met natuur en onze gezondheid vormen de kern van de missie van dit lectoraat.
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Application of animal manure to soils results in the introduction of manure-derived bacteria and their antimicrobial resistance genes (ARGs) into soils. ResCap is a novel targeted-metagenomic approach that allows the detection of minority components of the resistome gene pool without the cost-prohibitive coverage depths and can provide a valuable tool to study the spread of antimicrobial resistance (AMR) in the environment. We used high-throughput sequencing and qPCR for 16S rRNA gene fragments as well as ResCap to explore the dynamics of bacteria, and ARGs introduced to soils and adjacent water ditches, both at community and individual scale, over a period of three weeks. The soil bacteriome and resistome showed strong resilience to the input of manure, as manuring did not impact the overall structure of the bacteriome, and its effects on the resistome were transient. Initially, manure application resulted in a substantial increase of ARGs in soils and adjacent waters, while not affecting the overall bacterial community composition. Still, specific families increased after manure application, either through the input of manure (e.g., Dysgonomonadaceae) or through enrichment after manuring (e.g., Pseudomonadaceae). Depending on the type of ARG, manure application resulted mostly in an increase (e.g., aph(6)-Id), but occasionally also in a decrease (e.g., dfrB3) of the absolute abundance of ARG clusters (FPKM/kg or L). This study shows that the structures of the bacteriome and resistome are shaped by different factors, where the bacterial community composition could not explain the changes in ARG diversity or abundances. Also, it highlights the potential of applying targeted metagenomic techniques, such as ResCap, to study the fate of AMR in the environment.
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Manure application can spread antimicrobial resistance (AMR) from manure to soil and surface water. This study evaluated the role of the soil texture on the dynamics of antimicrobial resistance genes (ARGs) in soils and surrounding surface waters. Six dairy farms with distinct soil textures (clay, sand, and peat) were sampled at different time points after the application of manure, and three representative ARGs sul1, erm(B), and tet(W) were quantified with qPCR. Manuring initially increased levels of erm(B) by 1.5 ± 0.5 log copies/kg of soil and tet(W) by 0.8 ± 0.4 log copies/kg across soil textures, after which levels gradually declined. In surface waters from clay environments, regardless of the ARG, the gene levels initially increased by 2.6 ± 1.6 log copies/L, after which levels gradually declined. The gene decay in soils was strongly dependent on the type of ARG (erm(B) < tet(W) < sul1; half-lives of 7, 11, and 75 days, respectively), while in water, the decay was primarily dependent on the soil texture adjacent to the sampled surface water (clay < peat < sand; half-lives of 2, 6, and 10 days, respectively). Finally, recovery of ARG levels was predicted after 29–42 days. The results thus showed that there was not a complete restoration of ARGs in soils between rounds of manure application. In conclusion, this study demonstrates that rather than showing similar dynamics of decay, factors such as the type of ARG and soil texture drive the ARG persistence in the environment.
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Fish and vegetable protein sources are relatively underutilized for human consumption in comparison to meat, dairy and egg protein sources. Only part of the available fish proteins is used: fish is to small for human consumption and fish has a high proportion of by-products, up to 50% of fish weight is not used. This project aims to develop products and processes for creating healthy high valued consumer products based upon vegetable proteins and fish/crustacean proteins from by-products or from neglected fish. Three innovative processes are developed:1) Iso-electric solubilization and precipitation of fish/crustacean proteins from by-products,2) Networked vegetable/fish protein textures based upon low moisture extrusion processes3) Fibrous vegetable/fish protein textures produced with high moisture extrusion processes.Two innovative processes are applied:1) Food products with water-oil-water emulsions with isolated fish proteins2) Food products with sous-vide prepared fish fillets in semi industrial context.Different consumer product prototypes will be developed like fish nuggets, fish flakes and fish crackers.The Nuprotex project created successfully two new processes. Hanzehogeschool developed the process for fish protein isolation based upon iso electric solubilization and precipitation. With this process it was possible to recover about 15% weight of additional proteins from fish by-products. Please be aware that the yield of fish fillets from the fish is only about 30% of fish weight. So this is an important increase in food grade proteins! These Isolated Fish Proteins are successfully converted into several consumer prototype products like multiple emulsions for savory liquid products and fish cake/cracker applications. A sous-vide cooking process for fish fillets was developed with respect to microbial safety. It was shown that a microbial safe route could be developed, however further research is necessary to confirm these preliminary results.DIL has developed successfully an high moisture extrusion process for isolated fish proteins, grinded fish by products and vegetable proteins. This semi-finished product is successfully applied by for developing deep fried fish nuggets and fish burgers. DIL produced fish pellets which are suitable for applications as fish feed as is demonstrated in actual trials. Further research must demonstrate the quality of the feed product in actual growth experiments with fish.This project has clearly demonstrated that it is possible to produce with fish by-products added value consumer products. A possible increase of food-grade fish protein of about 15% on fresh weight base of processed fish is possible.
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VHL University of Applied Sciences (VHL) is a sustainable University of AppliedSciences that trains students to be ambitious, innovative professionals andcarries out applied research to make a significant contribution to asustainable world. Together with partners from the field, they contribute to innovative and sustainable developments through research and knowledge valorisation. Their focus is on circular agriculture, water, healthy food & nutrition, soil and biodiversity – themes that are developed within research lines in the variousapplied research groups. These themes address the challenges that are part ofthe international sustainability agenda for 2030: the sustainable developmentgoals (SDGs). This booklet contains fascinating and representative examplesof projects – completed or ongoing, from home and abroad – that are linked tothe SDGs. The project results contribute not only to the SDGs but to their teaching as well.
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Climate change is undermining the importance and sustainability of cooperatives as important organizations in small holder agriculture in developing countries. To adapt, cooperatives could apply carbon farming practices to reduce greenhouse gas emissions and enhance their business by increasing yields, economic returns and enhancing ecosystem services. This study aimed to identify carbon farming practices from literature and investigate the rate of application within cooperatives in Uganda. We reviewed scholarly literature and assed them based on their economic and ecological effects and trade-offs. Field research was done by through an online survey with smallholder farmers in 28 cooperatives across 19 districts in Uganda. We identified 11 and categorized them under three farming systems: organic farming, conservation farming and integrated farming. From the field survey we found that compost is the most applied CFP (54%), crop rotations (32%) and intercropping (50%) across the three categorizations. Dilemmas about right organic amendment quantities, consistent supplies and competing claims of residues for e.g. biochar production, types of inter crops need to be solved in order to further advance the application of CFPs amongst crop cooperatives in Uganda.
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