Post Doctoral Research Position On Aerobiology

Universities and Institutes of France

France

August 19, 2022

Description

  • Organisation/Company: Ecole Centrale de Lyon
  • Research Field: Environmental science › Ecology
  • Researcher Profile: Recognised Researcher (R2)
  • Application Deadline: 19/08/2022 18:00 - Europe/Brussels
  • Location: France › Ecully
  • Type Of Contract: Temporary
  • Job Status: Full-time
  • Hours Per Week: 40
  • Offer Starting Date: 03/10/2022
  • Mission

    The main objective of this post doc is to determine links between some sugars/sugar alocohols (S/SA) and specific bacteria and fungi in the atmosphere. It will further identify possible microbial sources of S/SA in the atmosphere. One focus will be on the possibility that glucose (one of the major S/SA in PM, of current unknown source) arises in situ from decomposition of cellulose directly in the PM. The co-occurrence of S/SA species and microorganisms will be studied, for various environments and seasons. For this purpose, a series of PM samples previously collected and analyzed will be sequenced.

    Context: Tropospheric particulate matter (PM) is involved in many aspects of Human environments, including large impacts on climate change, health, dispersion of pollutants, or damages to all compartments of the critical zone. Some impacts can be positive (the fertilization of Oceans), but most are negative, particularly when it comes to anthropogenic emissions. Assessing these impacts requires a proper understanding of some properties of PM (mass, size distribution, chemistry, physical and optical properties, ..), and also a good parametrization of the fluxes in and out of the atmosphere, in order to develop Chemical Transport Models (CTM). Primary Biogenic Organic Aerosols (PBOA) are not included in CTMs, despite their large contribution to the organic matter fraction of PM. As opposed to Secondary Biogenic Organic Aerosol (SBOA) that is formed in the atmosphere from the biogenic VOC's emitted by biota, PBOA is a subset of organic PM that comprises all particulate material of biogenic origin directly entering the atmosphere, and is indeed including components like plant debris, fungi, pollen, and viruses (Elbert et al., 2007; Hummel et al., 2015; Amato et al., 2017). The current estimate of the global flux to the atmosphere is between 10 and 310 Tg.year-1 (Hummel et al., 2015), to be compared to values of 21,3 (MACCCity) or 29,6 (CMIP6) Tg.year-1 for particulate organic components from anthropogenic origins (Rémy et al., 2019).

    A large part of this PBOA fraction is related to the fungi emission sources (Hummel et al., 2015; Marynowski et al., 2020; Wang et al., 2021). It follows that seasonal cycles of some sugars / sugar alcohols (S/SA) concentrations in atmospheric PM can probably be directly related to the microbiology of large biomes. However, this link has only been characterized for a limited number of cases and S/SA (Samake et al., 2020, 2021; Marynowski et al., 2020), and the main sources and drivers of many other S/SA in PM have not been identified yet. Currently, the mechanisms of S/SA emissions (along with their full organic cortege) to the atmosphere, and their fate and transfer to other ecosystem compartments remain poorly understood. Within the framework of the ANR call for proposals, a one-year post-doctoral and financial support was granted to ABS (atmospheric biogenic sugars), which sets up a collaboration between three laboratories, the Institute of Environmental Geosciences, the Ampere laboratory and EDYTEM in Chambéry. The majority of the experimental work will be carried out at the Ampere Lab in Lyon and IGE in Grenoble.

    The main objective of this post-doc is to determine The DNA of a total of 600 aerosol samples will be extracted at IGE using in-house protocols developed specifically for aerobiology. Subsequent molecular analysis will be carried out at AMPERE (C Larose in collaboration with IGE). Quantitative PCR analyses of 16S rRNA and 18S rRNA genes will be performed to estimate the abundance of bacterial and fungal cells per sample, respectively. Microbial community structure will be obtained by MiSeq Illumina amplicon sequencing of the V3-V4 region of bacterial/archaeal 16S rRNA genes and fungal ITS2 regions. The selection of the samples will be based on sequences with high vs low concentrations of S/SA from the different series / environments. A total of 600 filters will be selected and sequenced. The chemical composition of the field samples will be correlated to the microbiological data using a range of statistical approaches such as PCA, PCοA and NMDS to identify the possible sources and grouping of the S/SA. Different modelling approaches such as network analysis and gradient-boost machine learning will be used to link specific taxa to the wide range of S/SA and other tracers in the PM.

    Skills We are looking for a highly motivated candidate with a PhD degree in atmospheric chemistry related to the molecular characterisation of complex organic aerosols or microbially ecology, and a background in environmental science. The candidate must be able to integrate into teams of different cultures, have a strong taste for data analysis, be autonomous and know how to take initiatives. Experience in atmospheric/analytical chemistry and data mining in R language and a strong early-career track record in science communication would be a plus.

    General information

    Duration: 12 months

    Expected starting date : fall 2022

    Eligibility criteria

    We will consider applications from any candidate with the relevent skill sets required that has a PhD.

    Selection process

    The eligible candidates will undergo online interviews.

    Offer Requirements Skills/Qualifications

    We are looking for a highly motivated candidate with a PhD degree in atmospheric chemistry related to the molecular characterisation of complex organic aerosols or microbially ecology, and a background in environmental science. The candidate must be able to integrate into teams of different cultures, have a strong taste for data analysis, be autonomous and know how to take initiatives. Experience in atmospheric/analytical chemistry and data mining in R language and a strong early-career track record in science communication would be a plus.

    Contact Information
  • Organisation/Company: Ecole Centrale de Lyon
  • Organisation Type: Higher Education Institute
  • Website: https:// www. ec-lyon.fr
  • E-Mail: benedicte.martin@ec-lyon.fr
  • Country: France
  • City: Ecully
  • State/Province: France
  • Postal Code: 69130
  • Street: 36, av Guy de Collongue
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