20.500.12556/RUL-153458 Odziv mikrobne združbe obalnega morskega ekosistema na množično pojavljanje in odmiranje invazivne vrste rebrače Mnemiopsis leidyi The response of the microbial community to the mass occurrence and decay of the invasive ctenophore Mnemiopsis leidyi in the coastal ecosystem Množičnim pojavljanjem želatinoznega zooplanktona v morskih ekosistemih, ki so vse pogostejša, sledijo množična odmiranja, kar okoljskim mikroorganizmom omogoča večjo količino organske snovi v obliki detrita. Da bi bolje razumeli, kaj se zgodi z organsko maso detrita, smo v dvostopenjskem eksperimentu biorazgradnje in sukcesije spremljali sproščanje in porabo hranil ter dinamiko v mikrobni združbi. S fluorescentno in situ hibridizacijo smo opazovali specifične bakterijske populacije, za spremljanje metabolne aktivnosti pa smo uporabili komplet za ugotavljanje vitalnosti Redox sensor green in analog metionina L-homopropargilglicin. Določili smo organska in anorganska hranila, ki so se pri bakterijski razgradnji detrita sprostila v gojišče. V sukcesijskem delu eksperimenta smo poleg naštetih parametrov merili tudi količino klorofila a. Ugotovili smo, da dodajanje odmrle biomase M. leidyi pozitivno vpliva tako na številčnost bakterijske populacije kot tudi na metabolno aktivnost. Zaradi bakterijske aktivnosti so se v gojišče sprostila raztopljena organska in anorganska hranila. Sproščena hranila iz biorazgradnje detrita rebrač so v sukcesijskem delu eksperimenta pozitivno vplivala na koncentracijo klorofila a. To kaže, da se lahko določen delež organske snovi iz detrita rebrač prenese po prehranskem spletu v maso primarnih producentov. Massive occurrences of gelatinous zooplankton in marine ecosystems, which are becoming more frequent in some environmetns, are often followed by mass die-offs, which provide ambient seawater microorganisms with a substantial amount of detrital organic matter. In order to better understand the fate of the detrital organic matter in marine ecosystem, we monitored the release as well as consumption of nutrients and dissolved organic matter compounds and the dynamics of the microbial community in a microcosm experiment with biodegradation and succession stage. Metabolically active specific bacterial populations were determined by coupling fluorescent in situ hybridization with Redox sensor green and L-homopropargylglycine. We followed the organic and inorganic nutrients released into the culture medium during the bacterial degradation of detritus. In the succession part of the experiment, in addition to the above listed parameters, we also measured the concentration of chlorophyll a. We found that the addition of detrital M. leidyi biomass results in the increase of the abundance of bacterial populations, as well as on their metabolic activity. Dissolved organic and inorganic nutrients were released into the culture medium, some part due to bacterial activity and some due to chemical dissolution. Nutrients released from the biodegradation of ctenophore detritus supported increase of the biomass of primary producers, indicated by an increase of chlorophyll a concentration in the succession part of the experiment. This shows that a fraction of ctenophore detrital organic matter can be transferred via microbies to support biomass increase of the primary producers. okoljska mikrobiologija mikrobne združbe invazivne tuje vrste morski ekosistem rebrače detrit rebrače Mnemiopsis leidyi fluorescentna mikroskopija environmental microbiology microbial comunity invasive species marine ecosystems ctenophora ctenophoral detritus Mnemiopsis leidyi fluorescence microscopy true false false [K. Kosovac] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2024-01-08 07:15:17 2024-01-08 07:15:28 2024-01-09 11:15:43 0000-00-00 00:00:00 2024 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 579.26:593.8:574.5 236160 180115715 38305.pdf 38305.pdf 1 571EABAAC062B68AA1AF28E677A5AF45 d0a3011c9f03794d573acb05774d42ad47a9652823df710ab8e59dad19aa3790 57caca54-aded-11ee-8a1e-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=179452 Biotehniška fakulteta 0 0 0