Extracellular enzymatic activity and secondary production in free-living and marine-snow-associated bacteria

Author(s)
Markus Karner, Gerhard J. Herndl
Abstract

Abundance, production (measured as thymidine incorporation) and extracellular enzymatic activity in free-living and marine-snow-associated bacteria were measured in the northern Adriatic Sea. Although bacterial density and production were similar in both free-living and marine-snow-associated bacteria, hydrolytic activity (α- and β-glucosidase and l-aminopeptidase) was significantly higher in marine-snow-associated bacteria, in terms of both absolute and per-cell rates. As concentrations of dissolved total and monomeric carbohydrates and free amino acids in marine snow were very close to those in the ambient water, we suggest that the observed differences between free-living and marine-snow-associated baycteria do not simply reflect catabolic repression of enzyme expression in one of the bacterial components. Whether substrate induction is responsible for the observed higher hydrolase activity in marine-snow bacteria and/or whether there are distinct bacterial species obligatorily associated with marine snow remains unknown.

Organisation(s)
Journal
Marine Biology
Volume
113
Pages
341-347
No. of pages
7
ISSN
0025-3162
DOI
https://doi.org/10.1007/BF00347289
Publication date
06-1992
Peer reviewed
Yes
Austrian Fields of Science 2012
106021 Marine biology
ASJC Scopus subject areas
Ecology, Evolution, Behavior and Systematics, Ecology, Aquatic Science
Sustainable Development Goals
SDG 14 - Life Below Water
Portal url
https://ucrisportal.univie.ac.at/en/publications/59c0d70a-25c5-4adf-bb00-8bbf6f764b4b