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Plastic pollution in the marine realm is a severe environmental problem. Nevertheless, plastic may also serve as a potential carbon and energy source for microbes, yet the contribution of marine microbes, especially marine fungi to plastic degradation is not well constrained. We isolated the fungus Parengyodontium album from floating plastic debris in the North Pacific Subtropical Gyre and measured fungal-mediated mineralization rates (conversion to CO2) of polyethylene (PE) by applying stable isotope probing assays with 13C-PE over 9 days of incubation. When the PE was pretreated with UV light, the biodegradation rate of the initially added PE was 0.044 %/day. Furthermore, we traced the incorporation of PE-derived 13C carbon into P. album biomass using nanoSIMS and fatty acid analysis. Despite the high mineralization rate of the UV-treated 13C-PE, incorporation of PE-derived 13C into fungal cells was minor, and 13C incorporation was not detectable for the non-treated PE. Together, our results reveal the potential of P. album to degrade PE in the marine environment and to mineralize it to CO2. However, the initial photodegradation of PE is crucial for P. album to metabolize the PE-derived carbon.

Op 11 maart 2023 organiseerde de activiteitencommissie van het NGvA een middag over visgezondheid in Burgers’ Zoo met aansluitend een rondleiding door Burgers’ Ocean. De foyer van Burgers’ Bush, direct naast Burgers’ Ocean vult zich rond 13.00 uur met wel 100 leden, introducés, en een groep studenten Diergeneeskunde uit Utrecht. Het door de activiteitencommissie gekozen thema: een betere kijk op gezondheid van vissen, en de keuze van sprekers zal zeker hebben bijgedragen aan deze opkomst, maar ook de locatie en het aangekondigde kijkje achter de schermen van de Ocean prikkelt natuurlijk de nieuwsgierigheid van menigeen. De halve redactie van Aquacultuur ontmoet elkaar tijdens deze themamiddag en zo ziet u voor zich dit coöperatieve relaas van een zeer geslaagde bijeenkomst.

In the past decade, the potential of positioning LED lamps in between the canopy (intra-canopy) to enhance crop growth and yield has been explored in greenhouse cultivation. Changes in spatial heterogeneity of light absorption that come with the introduction of intra-canopy lighting have not been thoroughly explored. We calibrated and validated an existing functional structural plant model (FSPM), which combines plant morphology with a ray tracing model to estimate light absorption at leaflet level. This FSPM was used to visualize the light environment in a tomato crop illuminated with intra-canopy lighting, top lighting or a combination of both. Model validation of light absorption of individual leaves showed a good fit (R2 = 0.93) between measured and modelled light absorption of the canopy. Canopy light distribution was then quantified and visualized in three voxel directions by means of average absorbed photosynthetic photon flux density (PPFD) and coefficient of variation (CV) within that voxel. Simulations showed that the variation coefficient within horizontal direction was higher for intra-canopy lighting than top lighting (CV=48% versus CV= 43%), while the combination of intra-canopy lighting and top lighting yielded the lowest CV (37%). Combined intra-canopy and top lighting (50/50%) had in all directions a more uniform light absorption than intra-canopy or top lighting alone. The variation was minimal when the ratio of PPFD from intra-canopy to top lighting was about 1, and increased when this ratio increased or decreased. Intra-canopy lighting resulted in 8% higher total light absorption than top lighting, while combining 50% intra-canopy lighting with 50% top lighting, increased light absorption by 4%. Variation in light distribution was further reduced when the intra-canopy LEDs were distributed over strings at four instead of two heights. When positioning LED lamps to illuminate a canopy both total light absorption and light distribution have to be co

Most of the studies on light spectrum do not consider effects of spectrum perceived by different plant parts. Local and long-distance plant responses to localized light spectrum have hardly been studied in large plants. This paper aims to investigate whether local supplementation of FR results in local or long-distance architectural and growth responses in full-grown tomato plants. Tomato plants grown in a climate chamber were separated horizontally with white plastic at 85 days after sowing (lower half was 50 cm and upper half 15 cm long). The lower half was already full-grown and did not elongate anymore. The following 17 days both halves received 123 µmol m-2 s-1 red/blue light. The lower, upper, or none of the plant halves received 94 µmol m-2 s-1 additional far-red radiation (FR). FR supplied to the upper half increased petiole and internode elongation as well as specific leaf area (SLA) in the upper half of the plant, while petiole angle decreased. Moreover, dry weights of leaf stem (petiole+rachis+petiolules) and stem increased while leaf (lamina) dry weight decreased. Leaf area was unaffected. When FR was supplied to the lower half of the plant SLA, stem length, and stem dry weight of the upper half also increased, but to a lesser extent than when FR was supplied to the upper half. However, FR supplied to the lower half of the plant did not significantly affect other parameters such as petiole length, petiole angle and leaf dry weight of the upper plant half. We conclude that locally supplied FR has long-distance effects on length and dry weight of the stem and on SLA, while some other parameters (petiole elongation, petiole angle, leaf weight) are only locally affected. Hence, morphology and growth of upper young developing plant tissue can be influenced by light spectrum perceived by lower adult plant parts.

Deep-sea sponge grounds are hotspots of biodiversity, harbouring thriving ecosystems in the otherwise barren deep sea. It remains unknown how these sponge grounds survive in this food-limited environment. Here, we unravel how sponges and their associated fauna sustain themselves by identifying their food sources and food-web interactions using bulk and compound-specific stable isotope analysis of amino and fatty acids. We found that sponges with a high microbial abundance had an isotopic composition resembling organisms at the base of the food web, suggesting that they are able to use dissolved resources that are generally inaccessible to animals. In contrast, low microbial abundance sponges had a bulk isotopic composition that resembles a predator at the top of a food web, which appears to be the result of very efficient recycling pathways that are so far unknown. The compound-specific-isotope analysis, however, positioned low-microbial abundance sponges with other filter-feeding fauna. Furthermore, fatty-acid analysis confirmed transfer of sponge-derived organic material to the otherwise food-limited associated fauna. Through this subsidy, sponges are key to the sustenance of thriving deep-sea ecosystems and might have, due to their ubiquitous abundance, a global impact on biogeochemical cycles. Read the free Plain Language Summary for this article on the Journal blog.

How do we keep healthcare affordable and at the same time feasible? Will there be sufficient finance, and enough people to offer care? With these issues often the theme of sustainable care comes forward. Sustainable care is often interpreted as care that promotes the health of citizens, that maintains the high quality of care and improve where possible, and at the same time highlighting the cost of care. This applies to the care for addicts in the Netherlands no different. Also within the addiction care we are looking for sustainable solutions. Under sustainable we mean programs that work: promoting healing, supporting the recovery process and thereby preventing relapses. Sustainability also means it delivers more than just individual welfare. Here we can think of the social impact, inconvenience and insecurity, but also to the next generation. Especially on this last topic this article focuses. What is needed to work more sustainable and treat the addiction with an eye and focus on the next generation? This is about transgenerational transmission of addiction: the addiction is passed from (grand) parent to child. To further develop sustainability in the care for addiction is to get a clear picture of the children of addicted parents. There should be more attention to early detection of the possible dependence of older (and possibly child). In addition, attention should be to educate and make the timely discussion of the risks and possible existing education problems