Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
Biogeochemistry
Vol. 117, No: 1, 2014, Pages:
143-151

Differences in the substrate spectrum of extracellular enzymes in shallow lakes of differing trophic status

Kai Ziervogel, Dina Leech, Carol Arnosti

Department of Marine Sciences, University of North Carolina at Chapel Hill, Venable and Murray Halls, Chapel Hill, NC, 27599-3300, USA.

Abstract
Organic matter fluxes and food web interactions in lakes depend on the abilities of heterotrophic microbial communities to access and degrade organic matter, a process that begins with extracellular hydrolysis of high molecular weight substrates. In order to determine whether patterns of enzymatic hydrolysis vary among shallow lakes of different trophic status, we investigated the hydrolysis of six specific organic macromolecules (polysaccharides) in the spring and late summer in four adjacent shallow lakes of eutrophic, oligotrophic, and dystrophic status in coastal North Carolina, USA. The spectrum of enzyme activities detected differed strongly between lakes, with all six polysaccharides hydrolyzed in West Mattamuskeet in May, while only two substrates were hydrolyzed in Lake Phelps in August/September. Differences in the spectrum of enzyme activities, and therefore the capabilities of heterotrophic microbial communities, were likely driven by variations among lakes in primary productivity patterns, sediment–water interactions, and/or water chemistry. Our data represent a first step towards a better understanding of carbon substrate availability and differences in carbon cycling pathways in shallow lakes of different trophic status.

Keywoards: Enzymatic activities; Polysaccharide hydrolysis; Carbon cycling; Shallow lakes.


 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution