Optimizacija umjetnog osvjetljenja u uzgoju laboratorijskih kultura dijatomeja Achnanthes elongata i Poulinea lepidochelicola

master's thesis

• Title (english): Optimization of artificial light in the cultivation of laboratory diatom cultures Achnanthes elongata and Poulinea lepidochelicola
• Author: Antonija Matek
• Mentor: Sunčica Bosak (mentor)
• Mentor: Romana Gračan (mentor)
• Committee member: Sunčica Bosak (predsjednik povjerenstva)
• Committee member: Romana Gračan (član povjerenstva)
• Committee member: Tomislav Ivanković (član povjerenstva)
• Committee member: Marija Gligora Udovič (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2020-03-06, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Dijatomeje su jednostanični fotoautotrofni eukariotski organizmi koji nastanjuju plankton i bentos slatkovodnih i morskih ekosustava. Zajednice epizojskih dijatomeja također nastanjuju površine životinja poput ptica, kitova, te slatkovodnih i morskih kornjača. Vrste Achnanthes elongata i Poulinea lepidochelicola su nedavno opisane nove vrste dijatomeja s oklopa morskih kornjača. Stoga je cilj ovog istraživanja bio utvrditi optimalno umjetno osvjetljenje za laboratorijski uzgoj monokultura dvije tek opisane vrste dijatomeja, izolirane s oklopa i kože glavate želve (Caretta caretta) iz Jadranskog mora. U eksperimentu su korištena 3 soja vrste Achnanthes elongata i 2 soja vrste Poulinea lepidochelicola. Za svaki soj inokulirana su 2 biološka replikata s poznatim brojem stanica. Kulture su smještene u zatvorenom sustavu komore za rast stanica u uvjetima LED svjetlosti dvije različite temperature: umjereno-bijele boje temperature 5000 K i bijele boje temperature 6500 K. Biološki replikati praćeni su 39-40 dana te je određivana njihova brojnost. Za sve ispitivane sojeve dobivene su krivulje rasta iz kojih su vidljive faza prilagođavanja, eksponencijalna faza, te faza mirovanja. Stope rasta svih sojeva bile su unutar intervala od 0,30 - 0,58 dioba po danu, a vremena udvostručenja populacija od 1,31-2,28 dana. Rezultati ovoga rada pokazuju da sojevi obje vrste dijatomeja postižu veću gustoću i bolji rast ukoliko se u laboratoriju uzgajaju pri umjereno-bijeloj LED svjetlosti temperature 5000 K.

Abstract (english)

Diatoms are photoautotrophic eukaryotic microorganisms that are inhabiting phytoplankton and phytobentos of freshwater and marine ecosystems. Epizoic diatom communities are found on animals such as birds, whales, freshwater and sea turtles. Species Achnanthes elongata and Poulinea lepidochelicola are newly described epizoic diatoms living on the carapaces of sea turtles. The aim of the research was to determine the optimal artificial light for the cultivation of monocultures of these recently described diatoms isolated from the carapace and skin of loggerhead sea turtle (Caretta caretta) from the Adriatic Sea. Three strains of Achanthes elongata and two strains of Poulinea lepidochelicola were chosen for the experiments, and for each strain two biological replicates were used. The experiment started with a known number of cells inoculated for each replicate. Samples were placed in the closed culture room system with two different LED light illumination: the cold white light temperature 5000 K and warm white light temperature 6500 K. Biological replicates were observed for 39-40 days and diatom cells were counted. Growth curves were obtained that show different phases of growth: lag phase, exponential phase and stationary phase. The growth rates of all strains were within range of 0,30-0,58 division per day and doubling population times ranged between 1,31 and 2,28 days. Strains from both species grow better and achieve larger cell numbers under warm white light temperature 5000 K.

• Keywords: epizojske dijatomeje; temperatura svjetlosti; stopa rasta
• Keywords (english): epizoic diatoms; light temperature; growth rate
• Language: croatian
• URN:NBN: urn:nbn:hr:217:848961
• Study programme: Title: Ecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra ekologije i zaštite prirode (magistar/magistra ekologije i zaštite prirode)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-07-13 06:55:27