Aerobic microbial activity in deep sea abyssal clay

• Applicant: Professor William Orsi, Ph.D.
• Subject Area: Microbial Ecology and Applied Microbiology ; Oceanography
• Term: from 2017 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 325492802

• Final Report Year: 2021

Final Report Abstract

The results from this project have shed new light on the activity and distribution of aerobic and anaerobic microbial life in deep sea abyssal subseafloor sediments. Our findings provide new insights into how metabolism can support life and cellular proliferation over millions of years under energy limitation. To our knowledge, it is the first project comparing aerobic and anaerobic microbial communities and their metabolic activities in such settings. There is clearly a strong selection pressure, which is further evidence that the microbes living in these subseafloor settings are alive and respond differently to the environmental conditions. This selective response results in vastly different communities that in turn control the nature (either oxidative or reductive) of the carbon, nitrogen, and sulfur cycles. In addition to these exciting results, we also made some serendipitous discoveries regarding the evolution of subseafloor bacteria. We also demonstrated new methods, for example the application of the qSIP method using H218O to anoxic and oxic marine sediment communities, and the optimization of the Illumina MiniSeq for 16S, metagenome, and metatranscriptome sequencing in microbiome studies. LMU Munich Press Release “Fressen und gefressen werden in der Tiefe” (https://www.palaeontologie.geowissenschaften.uni-muenchen.de/aktuelles/news/fressen-und-gefressen-werden/index.html; regarding the 2018 Nature Microbiology publication)

Publications

• (2018) A 16S rRNA gene sequencing and analysis protocol for the Illumina MiniSeq platform. MicrobiologyOpen e00611
  Pichler M, Coskun O, Ortega AS, Conci N, Wörheide G, Vargas S, Orsi W
  
• (2018) Ecology and evolution of seafloor and subseafloor microbial communities. Nature Reviews Microbiology 16, 671-683
  Orsi W
  
• (2018) Predicted microbial secretomes and their target substrates in marine sediments. Nature Microbiology 3: 32-37
  Orsi W, Richards TA, Francis WR
  
• (2019) Archaea dominate oxic subseafloor communities over multimillion-year timescales. Science Advances 5:eaaw4108
  Vuillemin A, Wankel SD, Coskun OK, Magritsch T, Vargas S, Estes ER, Spivack AJ, Smith DC, Pockalny R, Murray RW, D’Hondt S, Orsi W
  
• (2019) Quantifying population specific growth in benthic bacterial communities under low oxygen using H218O. The ISME Journal 13, 1546-1559
  Coskun O, Özen V, Wankel S, Orsi W
  
• (2020) Atribacteria reproducing over millions of years in the Atlantic abyssal subseafloor. mBio 11:e01937-20
  Vuillemin A, Vargas S, Coskun O, Pockalny R, Murray R, Smith DC, D’Hondt S, Orsi W
  
• (2020) Exploring the abundance, metabolic potential, and gene expression of subseafloor Chloroflexi in million-year-old oxic and anoxic abyssal clay. FEMS Microbiology Ecology 96: fiaa223
  Vuillemin A, Kerrigan Z, D’Hondt S, Orsi W
  
• (2020) Physiological limits to life in anoxic subseafloor sediment. FEMS Microbiology Reviews 2: 219-231
  Orsi W, Schink B, Buckel W, Martin WF