Mogelijkheden en beperkingen van een gebiedsgerichte uitwerking van de Nitraatrichtlijn

Wordt de landbouw onevenredig hard getroffen in die gebieden in Nederland waar aan de nitraatconcentratie in het grondwater wordt voldaan? Die vraag probeerden Alterra en de Universiteit Utrecht te beantwoorden in een studie naar de mogelijkheden die de Nitraatrichtlijn biedt om de aanwijzing van nitraatuitspoelingsgevoelige gebieden (kwetsbare zones) en bijbehorende nitraatactieprogramma's te differentiëren naar de landbouw- en milieukundige omstandigheden in de verschillende regio's. Het doel hierachter is een betere aansluiting te krijgen bij de gebiedsgerichte uitwerking van de Kaderrichtlijn Water. De resultaten zijn gebaseerd op literatuurstudie, brainstormsessies, interviews en een bijeenkomst met actoren uit het veld. Een verdere differentiatie is technisch mogelijk via aanwijzing van specifieke kwetsbare zones en het uitzonderen van andere gebieden. Verwacht wordt echter dat het uit te zonderen areaal beperkt zal zijn. Meer perspectief bied een verdergaande (gebiedsgerichte) differentiatie van gebruiksnormen die van toepassing zijn op de aangewezen kwetsbare zones. Nitraatactieprogramma's zijn verder te 'harmoniseren' met stroomgebiedsplannen van de Kaderrichtlijn Water, maar dienen wel als zodanig herkenbaar in stand te blijven

A case series exploring the human milk polyclonal IgA1 response to repeated SARS-CoV-2 vaccinations by LC–MS based fab profiling

Introduction: Upon vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) humans will start to produce antibodies targeting virus specific antigens that will end up in circulation. In lactating women such antibodies will also end up in breastmilk, primarily in the form of secretory immunoglobulin A1 (SIgA1), the most abundant immunoglobulin (Ig) in human milk. Here we set out to investigate the SIgA1 clonal repertoire response to repeated SARS-CoV-2 vaccination, using a LC–MS fragment antigen-binding (Fab) clonal profiling approach.Methods: We analyzed the breastmilk of six donors from a larger cohort of 109 lactating mothers who received one of three commonly used SARS-CoV-2 vaccines. We quantitatively monitored the SIgA1 Fab clonal profile over 16 timepoints, from just prior to the first vaccination until 15  days after the second vaccination.Results: In all donors, we detected a population of 89–191 vaccine induced clones. These populations were unique to each donor and heterogeneous with respect to individual clonal concentrations, total clonal titer, and population size. The vaccine induced clones were dominated by persistent clones (68%) which came up after the first vaccination and were retained or reoccurred after the second vaccination. However, we also observe transient SIgA1 clones (16%) which dissipated before the second vaccination, and vaccine induced clones which uniquely emerged only after the second vaccination (16%). These distinct populations were observed in all analyzed donors, regardless of the administered vaccine.Discussion: Our findings suggest that while individual donors have highly unique human milk SIgA1 clonal profiles and a highly personalized SIgA1 response to SARS-CoV-2 vaccination, there are also commonalities in vaccine induced responses

Contribution of Eat1 and Other Alcohol Acyltransferases to Ester Production in Saccharomyces cerevisiae

Esters are essential for the flavor and aroma of fermented products, and are mainly produced by alcohol acyl transferases (AATs). A recently discovered AAT family named Eat (Ethanol acetyltransferase) contributes to ethyl acetate synthesis in yeast. However, its effect on the synthesis of other esters is unknown. In this study, the role of the Eat family in ester synthesis was compared to that of other Saccharomyces cerevisiae AATs (Atf1p, Atf2p, Eht1p, and Eeb1p) in silico and in vivo. A genomic study in a collection of industrial S. cerevisiae strains showed that variation of the primary sequence of the AATs did not correlate with ester production. Fifteen members of the EAT family from nine yeast species were overexpressed in S. cerevisiae CEN.PK2-1D and were able to increase the production of acetate and propanoate esters. The role of Eat1p was then studied in more detail in S. cerevisiae CEN.PK2-1D by deleting EAT1 in various combinations with other known S. cerevisiae AATs. Between 6 and 11 esters were produced under three cultivation conditions. Contrary to our expectations, a strain where all known AATs were disrupted could still produce, e.g., ethyl acetate and isoamyl acetate. This study has expanded our understanding of ester synthesis in yeast but also showed that some unknown ester-producing mechanisms still exist

Assessing the soundness of water governance: lessons learned from applying the 10 Building Blocks Approach

Sound governance is needed to address water issues, but soundness is a contested concept that should be further specified in societal debates. These debates can benefit from interdisciplinary knowledge. The 10 Building Blocks Approach, a tool developed to generate such knowledge, has been widely applied in research and teaching. In this paper, we draw on the literature and reflect on the experiences of using this approach by elucidating the strengths and weaknesses identified during its applications. Based on our reflections, we propose a revised version of the approach

Nutrient limitation leads to penetrative growth into agar and affects aroma formation in Pichia fabianii, P. kudriavzevii and Saccharomyces cerevisiae

Among fermentative yeast species, Saccharomyces cerevisiae is most frequently used as a model organism, although other yeast species may have special features that make them interesting candidates to apply in food-fermentation processes. In this study, we used three yeast species isolated from fermented masau (Ziziphus mauritiana) fruit, S. cerevisiae 131, Pichia fabianii 65 and Pichia kudriavzevii 129, and determined the impact of nitrogen and/or glucose limitation on surface growth mode and the production of volatile organic compounds (VOCs). All three species displayed significant changes in growth mode in all nutrient-limited conditions, signified by the formation of metafilaments or pseudohyphae. The timing of the transition was found to be species-specific. Transition in growth mode is suggested to be linked to the production of certain fusel alcohols, such as phenylethyl alcohol, which serve as quorum-sensing molecules. Interestingly, we did not observe concomitant increased production of phenylethyl alcohol and filamentous growth. Notably, a broader range of esters was found only for the Pichia spp. grown on nitrogen-limited agar for 21 days compared to nutrient-rich agar, and when grown on glucose- and glucose- plus nitrogen-limited agar. Our data suggest that for the Pichia spp., the formation of esters may play an important role in the switch in growth mode upon nitrogen limitation. Further biological or ecological implications of ester formation are discussed. Copyright © 2014 John Wiley & Sons, Ltd

A Direct MS-Based Approach to Profile Human Milk Secretory Immunoglobulin A (IgA1) Reveals Donor-Specific Clonal Repertoires With High Longitudinal Stability

Recently, a mass spectrometry-based approach was introduced to directly assess the IgG1 immunoglobulin clonal repertoires in plasma. Here we expanded upon this approach by describing a mass spectrometry-based technique to assess specifically the clonal repertoire of another important class of immunoglobulin molecules, IgA1, and show it is efficiently and robustly applicable to either milk or plasma samples. Focusing on two individual healthy donors, whose milk was sampled longitudinally during the first 16 weeks of lactation, we demonstrate that the total repertoire of milk sIgA1 is dominated by only 50-500 clones, even though the human body theoretically can generate several orders of magnitude more clones. We show that in each donor the sIgA1 repertoire only changes marginally and quite gradually over the monitored 16-week period of lactation. Furthermore, the observed overlap in clonal repertoires between the two individual donors is close to non-existent. Mothers provide protection to their newborn infants directly by the transfer of antibodies via breastfeeding. The approach introduced here, can be used to visualize the clonal repertoire transferred from mother to infant and to detect changes in-time in that repertoire adapting to changes in maternal physiology

Leuconostoc mesenteroides subsp. cremoris TIFN8 Genome sequencing and assembly

Leuconostoc mesenteroides subsp. cremoris isolated from a natural starter culture used in cheese manufacturing

Lactococcus cremoris subsp. cremoris TIFN7 Genome sequencing and assembly

Lactococcus lactis subsp. cremoris isolated from a natural starter culture used in cheese manufacturing

Lactococcus lactis subsp. lactis bv. diacetylactis str. TIFN4 Genome sequencing and assembly

Lactococcus lactis subsp. lactis biovar. diactylactis isolated from a natural starter culture used in cheese manufacturing