Linking extracellular enzymes to phylogeny indicates a predominantly particle-associated lifestyle of deep-sea prokaryotes

Author(s)
Zihao Zhao, Federico Baltar, Gerhard J. Herndl
Abstract

Heterotrophic prokaryotes express extracellular hydrolytic enzymes to cleave large organic molecules before taking up the hydrolyzed products. According to foraging theory, extracellular enzymes should be cell associated in dilute systems such as deep sea habitats, but secreted into the surrounding medium in diffusion-limited systems. However, extracellular enzymes in the deep sea are found mainly dissolved in ambient water rather than cell associated. In order to resolve this paradox, we conducted a global survey of peptidases and carbohydrate-active enzymes (CAZymes), two key enzyme groups initiating organic matter assimilation, in an integrated metagenomics, metatranscriptomics, and metaproteomics approach. The abundance, percentage, and diversity of genes encoding secretory processes, i.e., dissolved enzymes, consistently increased from epipelagic to bathypelagic waters, indicating that organic matter cleavage, and hence prokaryotic metabolism, is mediated mainly by particle-associated prokaryotes releasing their extracellular enzymes into diffusion-limited particles in the bathypelagic realm.

Organisation(s)
Functional and Evolutionary Ecology, Research Platform Vienna Metabolomics Center
External organisation(s)
Royal Netherlands Institute for Sea Research, Utrecht University
Journal
Science Advances
Volume
6
ISSN
2375-2548
DOI
https://doi.org/10.1126/sciadv.aaz4354
Publication date
04-2020
Peer reviewed
Yes
Austrian Fields of Science 2012
106021 Marine biology
ASJC Scopus subject areas
General
Portal url
https://ucris.univie.ac.at/portal/en/publications/linking-extracellular-enzymes-to-phylogeny-indicates-a-predominantly-particleassociated-lifestyle-of-deepsea-prokaryotes(83c9336e-7d41-47a8-a4f6-eac3eef64047).html