Fiziološki odgovor odabranih vrsta morskih dijatomeja na ograničene koncentracije fosfora

master's thesis

• Title (english): Physiological response to phosphorus stress of selected marine diatoms
• Author: Nikola Medić
• Mentor: Daniela Marić Pfannkuchen (mentor)
• Mentor: Zrinka Ljubešić (sumentor)
• Committee member: Zrinka Ljubešić (član povjerenstva)
• Committee member: Petar Kružić (član povjerenstva)
• Committee member: Vlasta Ćosović (član povjerenstva)
• Committee member: Danijel Orešić (član povjerenstva)
• Committee member: Nenad Buzjak (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2018-02-08, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

U ovom radu istražen je fiziološki odgovor morskih dijatomeja na ograničene koncentracije fosfora. U laboratorijskim eksperimentima korišteno je 6 vrsta morskih dijatomeja koje su redovito prisutne u fitoplanktonskoj zajednici sjevernog Jadrana: Pleurosigma elongatum, Thalassiosira rotula, Paralia sulcata, Pseudosolenia calcaravis, Chaetoceros peruvianus i Chaetoceros contortus. Svjetlosnom mikroskopijom i filogenetskom analizom potvrđena je taksonomska pripadnost vrsta. Fiziološki odgovor praćen je određivanjem stope rasta, mjerenjem aktivnost alkalne fosfataze, koncentracije fosfata i analizom lipida. Vrijednosti koncentracije fosfata ispod granice detekcije uzrokovale su promjene u stopi rasta, aktivaciju alkalne fosfataze i promjene u sastavu lipida. Rezultati ovog rada dokazuju da je fiziološki odgovor na ograničene koncentracije fosfora specifičan na razini vrste te da svaka od odabranih vrsta ima određene strategije za preživljavanje u uvjetima smanjene koncentracije fosfora. Ovakva istraživanja značajno doprinose razumijevanju kako pojedine vrste utječu na funkcioniranje ekosustava s ograničenim koncentracijama fosfata.

Abstract (english)

Physiological response of selected marine diatoms in phosphorus limited conditions was investigated. In laboratory experiments, we used six species of diatoms that are regularly present in the phytoplankton community of the northern Adriatic: Pleurosigma elongatum, Thalassiosira rotula, Paralia sulcata, Pseudosolenia calcaravis, Chaetoceros peruvianus and Chaetoceros contortus. All tested diatoms where identified to the species level by light microscopy and phylogenetic analysis. Physiological response of diatoms during the experiments was determined by growth rate, alkaline phosphatase activity, phosphate concentration and lipid composition. In phosphorus depleted conditions all diatoms species reduced their growth rates and have shown changes in lipid composition, and have activated the extracellular enzyme alkaline phosphatase. The results suggest that the diatoms develop species-specific adaptive strategies to phosphorus stress. Such investigations elucidate the diatom species specific response to the ecosystem functioning in the phosphorus limited conditions.

• Keywords: morske dijatomeje; alkalna fosfataza; sjeverni Jadran; ograničenje fosforom
• Keywords (english): diatoms; alkaline phosphatase; northern Adriatic; phosphorus limitation
• Language: croatian
• URN:NBN: urn:nbn:hr:217:399105
• Study programme: Title: Enviromental Sciences; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra struke znanosti o okolišu (magistar/magistra struke znanosti o okolišu)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-05-16 08:55:32