Distribution et abondance de microorganismes méthagéniques et méthatrophes dans les cours d'eau européens

International audienceGlobally, streams and rivers emit a significant amount of methane, a highly potent greenhouse gas. However, little is known about stream sediment microbial communities, driving the net methane balance in these systems, especially on their distribution and composition at large spatial scales. Within the project Euro Methane we investigated the diversity and abundance of methanogenic archaea and methane-oxidizing bacteria across 16 European streams (from northern Spain to central Sweden) via 16S rRNA sequencing and qPCR. We determined environmental drivers of both abundance and community composition and explored the link to measured potential methane production and oxidation rates of the respective sediments. We found that the community composition of methane-oxidizing bacteria significantly differed among the studied streams, while methanogenic archaea were more homogeneously distributed. Beyond the overall diversity trends, indicator species for stream types were identified. Methanogenic Methanosaeta sp. and methane-oxidizing Methyloglobulus sp. increased with geographical latitude and dominated in headwater streams (orders 1-3) with high oxygen levels and high proportions of pristine land within the catchment, while methanogenic Methanomethylovorans sp. and methane-oxidizing Methylocaldum spp. were more common in larger streams (orders 4-6) with higher discharge and agricultural influence. Potential methane production rates significantly increased with abundance of methanogenic archaea, while potential methane oxidation rates did not show significant correlations with methane oxidizing bacteria, presumably due to the more diverse physiological capabilities of this microbial group. Our study represents a holistic large-scale biogeographical overview of two microbial groups to enhance our understanding of the methane cycle within a heretofore understudied ecosystem

Impact of COVID19 pandemic on patients with rare diseases in Spain, with a special focus on inherited metabolic diseases

The Covid-19 pandemic soon became an international health emergency raising concern about its impact not only on physical health but also on quality of life and mental health. Rare diseases are chronically debilitating conditions with challenging patient care needs. We aimed to assess the quality of life and mental health of patients with rare diseases in Spain, with a special focus on inherited metabolic disorders (IMD). A prospective case-control study was designed, comparing 459 patients suffering from a rare disease (including 53 patients with IMD) and 446 healthy controls. Quality of life (QoL) and mental health were assessed using validated scales according to age: KINDL-R and the Pediatric Symptom Checklist (PSC) for children and the WhoQoL-Bref questionnaire, GAD and PHQ-9 in adults. First, children and adults (but not adolescents) with IMD showed greater psychological effects than controls (p = 0.022, p = 0.026 respectively). Second, when comparing QoL, only adult patients with IMD showed worse score than controls (66/100 vs 74,6/100 respectively, p = 0.017). Finally, IMD had better quality of life than other rare neurological and genetic diseases (p = 0.008) or other rare diseases (p < 0.001 respectively) but similar alteration of the mental status. Our data show that the pandemic had a negative impact on mental health that is more evident in the group of patients with IMD. Young age would behave as a protective factor on the perception of QoL. Furthermore, patients with IMD show a better QoL than other rare diseases

Les mesures nocturnes pour évaluer les flux de CO2 dans les cours d'eau : une étude internationale

International audienceGlobally, streams represent major CO2 emitters, accounting for approximately 70% of the total flux from inland waters. Hence, a proper understanding of carbon dioxide (CO2) uptake and emissions from streams is crucial for accurately estimating aquatic global carbon emissions. However, diurnal dynamics of these fluxes are still not comprehensively quantified, contributing to a high uncertainty in regional and global carbon budgets. Within the EuroRun project, the 1st Collaborative European Freshwater Science Project for Young Researchers, we aimed to assess spatial and seasonal variability of day- and night-time CO2 fluxes of 34 streams across 11 European countries. CO2 fluxes were measured with drifting flux chambers once per season at midday and midnight. The median CO2 fluxes during the day amounted to 1.4 µmol m-2 h-1 (IQR 0.5 to 3.1) and during the night to 2.1 µmol m-2 h-1 (IQR 0.95 to 3.75). The CO2 fluxes during night exceeded those during day by up to eight times. Interestingly, these differences occurred throughout all seasons and showed no latitudinal patterns. Our results highlight the importance of night-time fluxes to accurately assess CO2 fluxes from streams. As most studies are performed during the day, our survey indicates that global carbon budgets are currently underestimating the amount of CO2 released by streams