Izšķīdušo organisko vielu bioloģiskā izmantojamība bakterioplanktona un fitoplanktona klātbūtnē Rīgas līcī
View/ Open
Author
Purviņa, Santa
Co-author
Latvijas Universitāte. Bioloģijas fakultāte
Advisor
Balode, Maija
Date
2011Metadata
Show full item recordAbstract
Izškidušo organisko vielu biologiska izmantojamiba
bakterioplanktona un fitoplanktona klatbutne Rigas lici
Upju izškidušas organiskas vielas (DOM) nepartraukti papildina iesalo udenu ekosistemas,
veicinot to produktivitati. Masveida savairošanos Baltijas jura vasaras izraisa galvenokart slapekli
fiksejošas cianobakterijas, bet Rigas lica piekraste ari Microcystis aeruginosa. Promocijas darba ir
noskaidrota ar huminvielam bagatas alohtonas DOM biologiska izmantojamiba un ietekme uz
iesalu udenu bakterioplanktona - fitoplanktona sabiedribam. Upju ienesta DOM tiek paklauta
mikrobialai degradacijai jau piekrastes rajonos, bet atklatos udenos bakterioplanktons izmanto
autohtonas organiskas vielas. Ar cianobakterijam asocietas heterotrofas bakterijas mineralize
alohtono DOM, atbrivojot vienkaršus, viegli izmantojamus slapekla savienojumus (nitratus,
nitritus un amoniju), nodrošinot M. aeruginosa ar viegli izmantojamiem slapekla savienojumiem.
Atslegas vardi: heterotrofas bakterijas, Microcystis aeruginosa, DOM, DON, Rigas licis Biological use of dissolved organic matter by
bacterioplankton and phytoplankton in the Gulf of Riga
River brought dissolved organic matter (DOM) continuously supplements coastal
ecosystems, contributing to the productivity increase. Massive proliferation of
phytoplankton in the Baltic Sea in summers is mainly caused by nitrogen-fixing
cyanobacteria, but in coastal areas of the Riga Gulf also by Microcystis aeruginosa. In
dissertation is studied the contribution of brackish heterotrophic bacteria in
biodegradation of humic rich DOM and its effect on development of phytoplankton and
bacterioplankton communities. Riverine DOM is exposed to microbial mineralization
already in coastal areas but in open waters bacterioplankton use autochthonous organic
matter. Bacteria associated with M. aeruginosa consume riverine DOM and join
ammonification and nitrification process, supplying cyanobacteria with simple nitrogen
compounds.
Kay words: heterotrophic bacteria, Microcystis aeruginosa, DOM, DON, the Gulf of
Riga