Nanostrukturna karakterizacija stanica morskih dijatomeja izloženih kadmiju

master's thesis

• Title (english): Nanostructural characterization of marine diatom cells exposed to cadmium
• Author: Andrea Čačković
• Mentor: Tea Mišić Radić (mentor)
• Mentor: Zrinka Ljubešić (mentor)
• Committee member: Zrinka Ljubešić (predsjednik povjerenstva)
• Committee member: Mirela Sertić Perić (član povjerenstva)
• Committee member: Branimir Bertoša (član povjerenstva)
• Committee member: Nenad Judaš (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2018-10-25, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Cilj ovog diplomskog rada je nanostrukturna karakterizacija površine stanica slabo silificirane morske dijatomeje Cylindrothecae closterium izložene povišenoj koncentraciji kadmija, primjenom mikroskopije atomskih sila (AFM-a). Svjetlosnim mikroskopom praćena je dinamika rasta C. closterium pri odabranim koncentracijama kadmija u rasponu 1–1000 μg/L, a morfološke promjene na površini stanica izloženih kadmiju (500 μg/L i 1000 μg/L) karakterizirane su na nanoskali mikroskopijom atomskih sila.... More Posljedica povišenih koncentracija kadmija u kulturama C. closterium bila je inhibicija rasta odnosno smanjenje specifične brzina rasta i broja dioba stanica po danu, te morfološke promjene na površini ljušturica u obliku pojedinačnih sferičnih čestica i njihovih nakupina na pojedinim dijelovima stanice. Najizraženije promjene uočene su na stanicama koje su rasle pri koncentraciji kadmija 1000 μg/L i to na jače silificiranim dijelovima stanice, pojasu i oko rafe uz fibule, dok je manji broj čestica bio lociran na samoj valvi. Pretpostavljeno je da su navedene morfološke promjene posljedica utjecaja kadmija na mehanizam depozicije silicijevog dioksida što za rezultat ima pojavnost nepravilnih struktura na pojedinim, jače silificiranim, dijelovima ljušturice. Rezultati ovog rada predstavljaju doprinos boljem razumijevanje utjecaja teškog metala kadmija na dinamiku rasta i morfološke karakteristike morske dijatomeje C. closterium na nanometarskoj skali. Iako se dobiveni rezultati odnose na morsku dijatomeju Cylindrotheca closterium, oni također tvore temelj za daljnja istraživanja utjecaja teških metala na nanostrukturna svojstva stanica drugih vrsta fitoplanktona. Less

Abstract (english)

The aim of this Graduation Thesis is the nanostructural characterization of cell surface of lightly silicified marine diatom Cylindrotheca closterium exposed to increased cadmium concentration, using atomic force microscopy (AFM). C. closterium growth dynamics was monitored with optical microscope at selected cadmium concentrations in the range 1–1000 μg/L. Morphological changes on the cell surface of C. closterium exposed to cadmium (500 μg/L and 1000 μg/L) were characterized with AFM. The... More consequences of increased cadmium concentrations in C. closterium cultures were inhibition of growth and reduction of specific growth rates and number of cell divisions per day, also changes in the surface of the frustules were observed in the form of single spherical particles and their aggregates on certain parts of the cell. The most expressed changes were observed on more silicified parts of the cell, girdle band and around the raphe on fibulae of the cells that grew at cadmium concentration 1000 μg/L, while a smaller number of particles were located on the valves. These changes are likely to be due to the impact of cadmium on the silicon dioxide deposition mechanism, which results in the appearance of irregular structures on certain, more silicified, parts of the frustules. These results contribute to a better understanding of the impact of heavy metal cadmium on the growth dynamics and the morphological characteristics of the marine diatom C. closterium at the nanometric scale. Although, the results apply directly to Cylindrotheca closterium, they also form the basis for further investigation of the impact of heavy metals on the nanostructural properties of other phytoplankton species. Less

• Keywords: Cylindrotheca closterium; dinamika rasta; fitoplankton; kadmij; mikroskopija atomskih sila (AFM); morfološke promjene; morske dijatomeje; nanostrukturna karakterizacija.
• Keywords (english): atomic force microscopy (AFM); cadmium; Cylindrotheca closterium; growth dynamics; marine diatoms; morphological changes; phytoplankton; nanostructural characterization.
• Language: croatian
• URN:NBN: urn:nbn:hr:217:221395
• Study programme: Title: Integrated undergraduate and graduate university study of Biology and Chemistry Education; specializations in: Integrated undergraduate and graduate university study of Biology and Chemistry Education; Course: Integrated undergraduate and graduate university study of Biology and Chemistry Education; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra edukacije biologije i kemije (magistar/magistra edukacije biologije i kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2019-12-24
• Created on: 2018-12-03 12:26:04