IMIS | Flanders Marine Institute
 

Flanders Marine Institute

Platform for marine research

IMIS

Publications | Institutes | Persons | Datasets | Projects | Maps
[ report an error in this record ]basket (0): add | show Printer-friendly version

Influence of bacteria and salinity on diatom biogenic silica dissolution in estuarine systems
Roubeix, V.; Becquevort, S.; Lancelot, C. (2008). Influence of bacteria and salinity on diatom biogenic silica dissolution in estuarine systems. Biogeochemistry 88(1): 47-62. dx.doi.org/10.1007/s10533-008-9193-8
In: Biogeochemistry. Springer: Dordrecht; Lancaster; Boston. ISSN 0168-2563, more
Peer reviewed article  

Available in  Authors 

Keywords
    Bacillariophyceae [WoRMS]; Bacteria [WoRMS]; Marine; Brackish water; Fresh water
Author keywords
    bacteria; biogenic silica; diatoms; dissolution; estuaries; salinity

Authors  Top 

Abstract
    Dissolution of diatom biogenic silica (bSiO2) in estuaries and its control by water salinity and bacteria were investigated using the river euryhaline species Cyclotella meneghiniana as a model. Laboratory-controlled bioassays conducted at different salinities with an estuarine bacteria inoculum showed a faster dissolution of diatom bSiO2 at the lowest salinity where bacteria were the most abundant. However in another experiment, salinity increase clearly enhanced the dissolution of cleaned frustules (organic matter free). The presence of active bacteria might therefore predominate on the effect of salinity for freshly lysed diatoms whereas salinity might rather control dissolution of organic-matter-free frustule remains. Incubation of cultivated diatoms at different protease concentrations revealed that high proteolytic activities had little effect on bSiO2 dissolution at a 1-month scale in spite of an efficient removal of organic matter from the frustules. Altogether it is hypothesized that bacterial colonization increases bSiO2 dissolution by creating a microenvironment at the diatom surface with high ectoproteolytic activity but also via the release of metabolic byproducts since the presence of organic matter seems generally to facilitate diatom bSiO2 dissolution.

All data in IMIS is subject to the VLIZ privacy policy Top | Authors