Methanogenic microbial community of the Eastern Paris Basin: Potential for energy production from organic-rich shales

International audienc

Microbial methanogenesis in subsurface oil and coal

International audienc

WHERE DO DEHALOGENASES COME FROM ? A MULTIDISCIPLINARY STUDY HIGHLIGHTS THE PRIMARY ROLE OF HORIZONTAL GENE TRANSFER DURING RECENT FUNCTIONAL ADAPTATION

International audienceThe dehalogenases are enzymes responsible for the degradation of many chlorinated compounds. Most of them appear to be recent additions to the genomes of bacteria capable of xenobiotic compound degradation. To understand where these dehalogenases come from, a multidisciplinary approach was used. First, the proteic and nucleic sequence were analyzed by using bioinformatics techniques and no ancestor sequence was identified from which the dehalogenases could be derived. Another bioinformatics approach was applied which consisted of comparing the dehalogenase sequences between themselves. This approach showed a mosaic structure of these enzymes, suggesting horizontal gene transfer might have occurred. In addition, this approach defined several motifs that are common among the dehalogenases and that might represent functional characteristics. To support this observation, we applied an in vitro genetic shuffling method to try and reproduce the dehalogenases genes. To connect these observations to the potential for soil microbial communities to adapt by using different DNA fragments as defined by the motifs, we pyrosequenced the metagenome of a non-polluted soil in order to find the sources of the motifs among the original sequences of the soil metagenome

HOW MICROBIAL COMMUNITY STRUCTURE AND FUNCTION RELATE TO EACH OTHER WHEN CHLORINATED COMPOUNDS ARE INVOLVED

International audienceThe genetic resources available in an ecosystem are represented in part by the microbial community structure given that not all genes can be found in all prokaryotic species. The importance of the microbial community structure on the functional capacity to degrade chlorinated solvents in soil and groundwater was investigated. A combination of phylogenetic measurements using phylochip microarrays and 16S rDNA cloning and sequencing and functional gene quantification (both DNA and RNA) was used to evaluate the importance of structure on functional analyses. The quantitative PCR (qPCR) and Reverse Transcriptase-qPCR was applied to a range of genes implicated in chlorinated solvent degradation in the environment. The presence of chlorinated solvents induced a relative degree of stress on the microbial community, which was relieved by the chlorinated compound degradation. Certain members of the community were correlated to the degradation capacity while others were inversely correlated, probably due to inhibitory effect of the compounds. This work helps establish the relationship between structure and function at least within the narrow context of chlorinated solvent degradation. And improve the understanding of efficient community for the biodegradation of pollutant

WHO Global Situational Alert System: a mixed methods multistage approach to identify country-level COVID-19 alerts

Background Globally, since 1 January 2020 and as of 24 January 2023, there have been over 664 million cases of COVID-19 and over 6.7 million deaths reported to WHO. WHO developed an evidence-based alert system, assessing public health risk on a weekly basis in 237 countries, territories and areas from May 2021 to June 2022. This aimed to facilitate the early identification of situations where healthcare capacity may become overstretched.Methods The process involved a three-stage mixed methods approach. In the first stage, future deaths were predicted from the time series of reported cases and deaths to produce an initial alert level. In the second stage, this alert level was adjusted by incorporating a range of contextual indicators and accounting for the quality of information available using a Bayes classifier. In the third stage, countries with an alert level of ‘High’ or above were added to an operational watchlist and assistance was deployed as needed.Results Since June 2021, the system has supported the release of more than US$27 million from WHO emergency funding, over 450 000 rapid antigen diagnostic testing kits and over 6000 oxygen concentrators. Retrospective evaluation indicated that the first two stages were needed to maximise sensitivity, where 44% (IQR 29%–67%) of weekly watchlist alerts would not have been identified using only reported cases and deaths. The alerts were timely and valid in most cases; however, this could only be assessed on a non-representative sample of countries with hospitalisation data available.Conclusions The system provided a standardised approach to monitor the pandemic at the country level by incorporating all available data on epidemiological analytics and contextual assessments. While this system was developed for COVID-19, a similar system could be used for future outbreaks and emergencies, with necessary adjustments to parameters and indicators