Fototrofni uzgoj dijatomeje Nitzschia sp.

master's thesis

• Title (english): Phototrophic cultivation of diatom Nitzschia sp.
• Author: Marija Kuzmić
• Mentor: Mirela Ivančić - Šantek (mentor)
• Committee member: Ksenija Markov (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); (Laboratory for Biochemical Engineering, Industrial Microbiology and Malting and Brewing Technology); Zagreb
• Defense date and country: 2020-11-06, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Dijatomeje su eukariotski jednostanični mikroorganizmi koji sintetiziraju različite bioaktivne tvari i proizvode s dodanom vrijednošću, kao i lipide koji se mogu koristiti kao alternativna sirovina za proizvodnju biodizela. Većina morskih dijatomeja može rasti samo fototrofno pri čemu koriste svjetlosnu energiju i asimiliraju CO2. Međutim produktivnost i koncentracija biomase fototrofno uzgojene kulture je vrlo mala. U ovom istraživanju, optimirana je hranjiva podloga f/2 za uzgoj dijatomeje Nitzschia sp. tako da su mijenjane koncentracije tri limitirajuća makroelemenata (silicij, dušik i fosfor). Najveći prinos biomase od 0,7611 g Lˉ¹ i produktivnost od 0,0544 g Lˉ¹ danˉ¹ postignuti su na modificiranoj f/2 hranjivoj podlozi s deseterostruko većom koncentracijom silicija, te četverostruko većom koncentracijom dušika i fosfora u odnosu na izvornu f/2 hranjivu podlogu. Također je istražen utjecaj sastava modificirane f/2 hranjive podloge na sastav biomase. Stanična biomasa sadržavala je povećanu količinu proteina i višestruko nezasićenih masnih kiselina. Šaržni uzgoj s pritokom supstrata proveden je u f/2 optimiranoj hranjivoj podlozi. Najveća produktivnost biomase od 0,7150 g Lˉ¹danˉ¹ zabilježena je između 7. i 8. dana uzgoja. Najzastupljenije makromolekule u biomasi su bili proteini, a zatim ugljikohidrati i lipidi.

Abstract (english)

Diatoms are eukaryotic unicellular microorganisms which produce a variety of bioactive compounds and value-added products as well as lipids which can be used as an alternative feedstock for the production of biodiesel. Most of the marine diatoms grow only photothrophically by harvesting sunlight and assimilating CO2. However, the productivity and biomass concentration in phototrophically grown culture is very low. In this research, growth medium f/2 for the cultivation of diatom Nitzschia sp. was optimized by changing concentrations of three limiting macroelements (silica, nitrogen and phosphorus). The highest biomass yield of 0,7611 g Lˉ¹ and productivity of 0,0544 g Lˉ¹ dayˉ¹ was achieved with modified f/2 growth medium, which had a tenfold higher concentration of silica and fourfold higher concentrations of nitrogen and phosphorus, compare to original f/2 medium. Effect of modified f/2 growth medium on the composition of cell biomass was also determined. Cell biomass contained increased content of proteins and polyunsaturated fatty acids. Phototrophic fed-batch cultivation was conducted using optimized f/2 growth media. The highest biomass productivity of 0,7150 g Lˉ¹ dayˉ¹ was accomplished between 7. and 8. day of cultivation. The most abundant macromolecule in cell biomass were proteins, followed by carbohydrate and lipid.

• Keywords: Nitzschia sp.; f/2 hranjiva podloga; fototrofni uzgoj; proteini; lipidi
• Keywords (english): Nitzschia sp.; f/2 growth medium; phototrophic cultivation; proteins; lipids
• Language: croatian
• URN:NBN: urn:nbn:hr:159:383111
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2021-01-20 12:17:32