Caribbean coral reefs are in rapid decline and artificial reefs are increasingly often deployed to restore lost three-dimensional structure. The majority of artificial reefs and other marine infrastructure is built from concrete, with Ordinary Portland Cement (CEM I) as the most important ingredient. However, the production of CEM I results in substantial CO2 emissions. In addition, there are indications that the material is colonized by different benthic assemblages compared to natural reefs. To make artificial reefs more sustainable and ecologically optimal, research into alternative materials is required. For this study, CEM I was compared with five alternative substrates: a mixture of CEM III cement with recycled CEM I fines (CEM III), Calcium Sulfoaluminate cement (CSA), geopolymer-sediment tiles (GS), lime-sediment tiles (LS), and Xiriton (E0). Settlement of the long-spined sea urchin Diadema antillarum on the different materials was tested under marine laboratory conditions. Competent D. antillarum larvae were added to beakers with a tile made from one of the substrates and monitored for settlement after two days. Half of the tiles of each material were covered with a four-week old biofilm, the other half had no biofilm. Results show that substrate type and the presence of a biofilm affected settlement rates significantly. After 48h, highest settlement rates were found on CEM III with biofilm (30% settlement), CSA with biofilm (26% settlement) and E0 with biofilm (20% settlement). Without biofilm, the same substrates yielded only 4 to 10% settlement. CEM I, GS, and LS had overall low settlement rates (<5%) irrespective of biofilm. Post-settlement morphology was not affected by substrate type or biofilm, with juveniles having a mean test diameter of 593 ± 12 µm and a mean spine length of 487 ± 27 µm. This study provides alternative choices for regular concrete that enhance the larval settlement of the key herbivore D. antillarum. We recommend studying these alternative materials in the field to obtain a better understanding of the effects of substrate on the ecological community development over larger time- and spatial scales.
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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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Abstract: Aureobasidium is omnipresent and can be isolated from air, water bodies, soil, wood, and other plant materials, as well as inorganic materials such as rocks and marble. A total of 32 species of this fungal genus have been identified at the level of DNA, of which Aureobasidium pullulans is best known. Aureobasidium is of interest for a sustainable economy because it can be used to produce a wide variety of compounds, including enzymes, polysaccharides, and biosurfactants. Moreover, it can be used to promote plant growth and protect wood and crops. To this end, Aureobasidium cells adhere to wood or plants by producing extracellular polysaccharides, thereby forming a biofilm. This biofilm provides a sustainable alternative to petrol-based coatings and toxic chemicals. This and the fact that Aureobasidium biofilms have the potential of self-repair make them a potential engineered living material avant la lettre. Key points: •Aureobasidium produces products of interest to the industry •Aureobasidium can stimulate plant growth and protect crops •Biofinish of A. pullulans is a sustainable alternative to petrol-based coatings •Aureobasidium biofilms have the potential to function as engineered living materials.
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Prioritaire instellingen dienen in het bezit te zijn van een beheersplan legionellapreventie. Desondanks worden in de praktijk geregeld te hoge aantallen legionellabacteriën aangetroffen in monsters genomen uit thermostatische douchemengkranen. Het is niet bekend of de thermostatische douchemengkraan zelf de oorzaak is van deze overschrijdingen. Daarom is onderzoek uitgevoerd aan douchemengkranen die afkomstig zijn uit de praktijk. De resultaten laten zien dat de douchemengkraan een rol kan spelen bij een overschrijding, maar dat ook andere onderdelen van de leidingwaterinstallatie de oorzaak kunnen zijn.
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Abstract Aureobasidium is omnipresent and can be isolated from air, water bodies, soil, wood, and other plant materials, as well as inorganic materials such as rocks and marble. A total of 32 species of this fungal genus have been identified at the level of DNA, of which Aureobasidium pullulans is best known. Aureobasidium is of interest for a sustainable economy because it can be used to produce a wide variety of compounds, including enzymes, polysaccharides, and biosurfactants. Moreover, it can be used to promote plant growth and protect wood and crops. To this end, Aureobasidium cells adhere to wood or plants by producing extracellular polysaccharides, thereby forming a biofilm. This biofilm provides a sustainable alternative to petrol-based coatings and toxic chemicals. This and the fact that Aureobasidium biofilms have the potential of self-repair make them a potential engineered living material avant la lettre.
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Tropical western Atlantic reefs have gradually shifted from being dominated by corals to being mainly covered by macroalgae. The mass-mortality of the sea urchin Diadema antillarum in the 80s and the slow to non-existent recovery exacerbated this shift. Chemical cues associated with these reefs are expected to have shifted too with potential negative effects on larval recruitment, possibly limiting recovery of important species like D. antillarum. In this study, we tested the effects of naturally derived biofilm and macroalgae species native to Caribbean coral reefs on the settlement rate of cultured D. antillarum larvae in two separate experiments. Crustose coralline algae (CCA) were included in both experiments, making it possible to compare settlement rates from both experiments. A biofilm of one week old yielded significantly lower settlement rates compared to two, four, and six weeks old biofilm and the highest settlement rate was found for CCA with over 62% of total larvae. All six tested macroalgae species resulted in settled larvae, with little significant difference between algal species, partly due to a high variation in settlement rates within treatments. Sargassum fluitans induced the highest settlement rate with 33%, which was not significantly different from CCA with 29%. We conclude that dominant macroalgae species likely to be encountered by D. antillarum on shifted reefs are no major constraint to settlement. Our findings increase the understanding of alternative stable state settlement dynamics for a keystone coral reef herbivore.
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Floating wetland treatment systems (FWTS) are an innovative stormwater treatment technology currently being trialled on a larger scale in Australia. FWTS provide support for selected plant species to remove pollutants from stormwater discharged into a water body. The plant roots provide large surface areas for biofilm growth, which serves to trap suspended particles and enable the biological uptake of nutrients by the plants. As FWTS can be installed at the start of the construction phase, they can start treating construction runoff almost immediately. FWTS therefore have the potential to provide the full range of stormwater treatment (e.g. sediment and nutrient removal) from the construction phase onwards. A 2,100m 2 FWTS has been installed within a greenfield development site on the Sunshine Coast, Queensland. A four-year research study is currently underway which will target the following three objectives; (1) characterise the water quality of runoff from a greenfield development in the construction and operational phases; (2) verify the stormwater pollution removal performance of a FWTS during the construction and operational phases of a greenfield development; and (3) characterise the ability of FWTS to manage urban lake health. This extended abstract presents the proposed research methodology and anticipated outcomes of the study
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Ecosystem engineering research has recently demonstrated the fundamental importance of non-trophic interactions for food-web structure. Particularly, by creating benign conditions in stressful environments, ecosystem engineers create hot beds of elevated levels of recruitment, growth, and survival of associated organisms; this should fuel food webs and promote production on the ecosystem scale. However, there is still limited empirical evidence of the influence of non-trophic interactions on the classical food-web processes that determine energy transfer, that is, consumer–resource interactions. On the basis of a biomanipulation experiment covering 600 m2 of an intertidal flat, we show that ecosystem engineers influence resource uptake efficiency and the accumulation of algae following nutrient enrichment in a soft-sediment food web. Nutrient additions increased chlorophyll a concentrations in the sediment by 90%, but only in plots where we also introduced high densities (2000 per m2) of a burrowing bivalve, the common cockle Cerastoderma edule. The artificial cockle beds increased the nutrient uptake efficiency of the biofilm and promoted sediment accumulation, which suggests that the cockles facilitated the sediment-living algae by increasing sediment stability. This indicates that ecological interactions, rather than the availability of nutrients per se, set the limits for production in this coastal ecosystem. Our results emphasize the need to include facilitation theory and recognize that positive interactions between species are key to understand, manage, and restore ecosystems under human influence.
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Objectives: The aim of this scoping review was threefold: 1. to identify existing definitions of oral frailty and similar terms in gerodontology literature; 2. to assess the oral frailty definitions and analyze whether these are well formulated on a conceptual level; and 3. in the absence of existing definitions meeting the criteria for good conceptual definitions, a new conceptual definition of oral frailty will be presented. Methods: A search was performed in electronic databases and internet search engines. Studies explaining or defining oral frailty or similar terms were of interest. A software-aided procedure was performed to screen titles and abstracts and identify definitions of oral frailty and similar terms. We used a guide to assess the quality of the oral frailty definitions on methodological, linguistic, and content-related criteria. Results: Of the 1,528 screened articles, 47 full-texts were reviewed. Thirteen of these contained seven definitions of oral frailty and ten definitions of similar terms. We found that all definitions of oral frailty contain the same or equivalent characteristics used to define the concepts of ’oral health’, ’deterioration of oral function’, and ’oral hypofunction’. Between the seven definitions, oral frailty is described with a different number and combination of characteristics, resulting in a lack of conceptual consistency. None of the definitions of oral frailty met all criteria. Conclusion: According to our analysis, the current definitions of oral frailty cannot be considered ’good’ conceptual definitions. Therefore, we proposed a new conceptual definition: Oral frailty is the age-related functional decline of orofacial structures.
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De Nederlandse levensmiddelenindustrie zal moet innoveren om te kunnen voldoen aan de huidige en toekomstige maatschappelijke eisen op het gebied van duurzaamheid, gezondheid en veiligheid. De Kombucha markt is een nieuwe zeer snel groeiende markt met een voorspelde jaarlijkse groei van 23% naar 10,4 miljard USD in 2027. De Kombucha drank is een gefermenteerde thee en biedt daarmee een gezond en alcoholvrij alternatief voor suikerhoudende dranken. Tijdens het fermentatieproces van Kombucha vormen de micro-organismen naast de vloeistof een biofilm bestaande uit bacterieel cellulose. Bij bedrijven waar Kombucha wordt gebrouwen, zoals Untamed Kombucha, ontstaat deze biofilm als een reststroom die tot op heden niet wordt gebruikt. BIOMA Lab heeft een procedé ontwikkeld om de biofilm te prepareren in een materiaal dat waterafstotend en geurloos is, met een aangename en zachte tactiliteit. Dit materiaal kan worden gebruikt als vervanging voor textiel of leer dat, in tegenstelling tot milieubelastende materialen op basis van plastic of dierlijk leer, 100% biobased en circulair is. Door beide processen te combineren en tegelijkertijd te optimaliseren, kan een meer rendabel en duurzamer proces worden opgezet voor het brouwen van Kombucha samen met het biobased leer product uit deze reststroom vanuit de Nederlandse levensmiddelenindustrie. Als kennisinstelling kan de HAN samen met docent-onderzoekers en studenten bijdragen aan het project door onderzoek uit te voeren naar de invloed van procesomstandigheden op de aanwezige soorten van micro-organismen, de smaak van de Kombucha en de kwaliteit & opbrengst van het bacterieel cellulose om zodoende een stabiel productieproces voor beide producten te ontwikkelen. Aan het einde van het project zullen de inzichten t.a.v. een nieuw circulair productontwerp worden gedeeld op de jaarlijkse Kombucha Summit en in workshops.
