On Single-Cell Enzyme Assays in Marine Microbial Ecology and Biogeochemistry

Frontiers in Marine Science

Carol Arnosti¹  Dan Seale³  Ronnie N. Glud³  John Paul Balmonte⁵  Steven J. Hallam⁷  Mathias Middelboe⁸  Sachia J. Traving⁹ 

[1] Nordcee, University of Southern Denmark, Odense, Denmark;Danish Institute for Advanced Study, University of Southern Denmark, Odense, Denmark;;Department of Biology, HADAL &Department of Earth, Marine and Environmental Sciences, University of North Carolina, Chapel Hill, Chapel Hill, NC, United States;Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada;Genome Science and Technology Program, University of British Columbia, Vancouver, BC, Canada;Graduate Program in Bioinformatics, University of British Columbia, Vancouver, BC, Canada;Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada;Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark;Tokyo University of Marine Science and Technology, Tokyo, Japan;

关键词: extracellular enzymes;    single-cell;    microfluidic droplet;    carbon cycle;    microbial ecology;   

DOI  :  10.3389/fmars.2022.846656

来源: DOAJ

【 摘 要 】

Extracellular enzyme activity is a well-established parameter for evaluating microbial biogeochemical roles in marine ecosystems. The presence and activity of extracellular enzymes in seawater provide insights into the quality and quantity of organic matter being processed by the present microorganisms. A key challenge in our understanding of these processes is to decode the extracellular enzyme repertoire and activities of natural communities at the single-cell level. Current measurements are carried out on bulk or size-fractionated samples capturing activities of mixed populations. This approach – even with size-fractionation – cannot be used to trace enzymes back to their producers, nor distinguish the active microbial members, leading to a disconnect between measured activities and the producer cells. By targeting extracellular enzymes and resolving their activities at the single-cell level, we can investigate underlying phenotypic heterogeneity among clonal or closely related organisms, characterize enzyme kinetics under varying environmental conditions, and resolve spatio-temporal distribution of individual enzyme producers within natural communities. In this perspective piece, we discuss state-of-the-art technologies in the fields of microfluidic droplets and functional screening of prokaryotic cells for measuring enzyme activity in marine seawater samples, one cell at a time. We further elaborate on how this single-cell approach can be used to address research questions that cannot be answered with current methods, as pertinent to the enzymatic degradation of organic matter by marine microorganisms.

【 授权许可】

Unknown