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SUMMARY:ENAC Seminar Series by Dr A. Ebrahimi
DTSTART:20201103T150000
DTEND:20201103T154500
DTSTAMP:20260511T123722Z
UID:4c78a4713cd0124f98e4821993d925cffacbe42c2f4eb1214aab9951
CATEGORIES:Conferences - Seminars
DESCRIPTION:Dr Ali Ebrahimi\n15:00 – 15:45 – Dr Ali Ebrahimi\nPostdoc 
 at Massachusetts Institute of Technology (MIT)\, Cambridge\, USA\n\nMicrob
 ial community dynamics in soil aggregates shape carbon and nitrogen cycles
  at the ecosystem level\n\nSoil microbial community dynamics and function 
 play a key role in shaping the global biogeochemical cycles with a signifi
 cant impact on soil health and productivity. The complex ecological functi
 oning of microbial communities is often promoted by multispecies interacti
 ons in soil biological hotspots such as soil aggregates. Microbial communi
 ties inhabiting soil aggregates dynamically adjust their activity and comp
 osition in response to variations in water content and availability of car
 bon and nitrogen. These dynamics shape signatures of biogeochemical activi
 ty and gas fluxes from soil profiles. In this talk\, I will represent a no
 vel mechanistic model to bridge the various scales of relevance to soil mi
 crobial processes ranging from pores to aggregates and soil profiles. The 
 model reveals a dynamic interplay between oxic and anoxic microsites that 
 are jointly shaped by water dynamics and the self-organization of aerobic 
 and anaerobic microbial communities. The spatial extent of anoxic niches (
 hotspots) flicker in time (hot moments) and support significant anaerobic 
 microbial activity even in aerated soil profiles. The results quantify imp
 acts of aggregate size distribution and dynamic shifts in water content on
  CO2 and N2O production rates in soil profiles in good agreement with our 
 “soil column” experimental data.\nI will then present how socio-ecolog
 ical interactions among microbes contribute to decompose complex particula
 te organic matter as the key step in the global carbon cycle. Using a comb
 ination of computational models and experiments\, I will show that microbi
 al populations “team-up” by forming multicellular units to degrade rec
 alcitrant particulate organic matter where individual cells facilitate eac
 h other’s activity. I will end by discussing how these results could hel
 p to predict the carbon use efficiency at the ecosystem level and how to e
 ngineer scenarios to facilitate the degradation of recalcitrant plastics i
 n nature.\n\n\nShort bio:\nAli Ebrahimi is an SNSF (Swiss National Science
  Foundation) postdoctoral fellow in Parsons lab at Massachusetts Institute
  of Technology\, specializing in microbial ecology and soil physics. He is
  interested in understanding the mechanisms that control microbial process
 es at the micrometer scale and their impact on the ecosystem functions suc
 h as the carbon cycle. Ali received his MSc in Chemical Engineering from S
 harif University of Technology (Tehran\, Iran). He completed his Ph.D. at 
 ETH Zurich\, focusing on developing mechanistic models for microbial proce
 sses in soil aggregates where he received ETH medal for his outstanding di
 ssertation. Ali is also the recipient of two PostDoc Mobility Fellowships 
 from the Swiss National Science Foundation. Ali is a scientific collaborat
 or and consultant in multiple environmental restoration and protection pro
 jects around the globe including sustainable land management in the black 
 soil region of northeast china and water resources restoration in Iran und
 er drought stress.\n\n 
LOCATION:Zoom https://epfl.zoom.us/j/81460095854
STATUS:CONFIRMED
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