Bacterial Versus Archaeal Origin of Extracellular Enzymatic Activity in the Northeast Atlantic Deep Waters

Author(s)
Federico Baltar, Javier Aristegui, Josep M. Gasol, Taichi Yokokawa, Gerhard J. Herndl
Abstract

We determined the total and dissolved extracellular enzymatic activity (EEA) of alpha-glucosidase and beta-glucosidase (AGase and BGase), alkaline phosphatase (APase) and leucine aminopeptidase (LAPase) activities in the epi-, meso- and bathypelagic waters of the subtropical Northeast Atlantic. EEA was also determined in treatments in which bacterial EEA was inhibited by erythromycin. Additionally, EEA decay experiments were performed with surface and deep waters to determine EEA lifetimes in both water masses. The proportion of dissolved to total EEA (66-89 %, 44-88 %, 57-82 % and 86-100 % for AGase, BGase, APase and LAPase, respectively) was generally higher than the cell-associated (i.e., particulate) EEA. The percentage of dissolved to total EEA was inversely proportional to the percentage of erythromycin-inhibited to total EEA. Since erythromycin-inhibited plus dissolved EEA equaled total EEA, this tentatively suggests that cell-associated EEA in the open oceanic water column is almost exclusively of bacterial origin. The decay constants of dissolved EEA were in the range of 0.002-0.048 h(-1) depending on the type of extracellular enzyme, temperature and depth in the water column. Although dissolved EEA can have different origins, the major contribution of Bacteria to cell-associated EEA and the long life-time of dissolved EEA suggest that Bacteria-and not mesophilic Archaea-are essentially the main producers of EEA in the open subtropical Northeast Atlantic down to bathypelagic layers.

Organisation(s)
Functional and Evolutionary Ecology
External organisation(s)
Royal Netherlands Institute for Sea Research, Universidad de Las Palmas de Gran Canaria, Consejo Superior de Investigaciones Científicas (CSIC)
Journal
Microbial Ecology: an international journal
Volume
65
Pages
277-288
No. of pages
12
ISSN
0095-3628
DOI
https://doi.org/10.1007/s00248-012-0126-7
Publication date
02-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
106021 Marine biology
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/bacterial-versus-archaeal-origin-of-extracellular-enzymatic-activity-in-the-northeast-atlantic-deep-waters(590ac09f-28c7-47b9-b827-dfaf44f65ffd).html