Optimizacija rasta mikroalge Picochlorum sp. i proizvodnje lipida u stresnim uvjetima

master's thesis

• Title (english): Optimization of the growth of microalgae Picochlorum sp. and lipid production in stress conditions
• Author: Lucija Mlakić
• Mentor: Mirela Ivančić - Šantek (mentor)
• Mentor: Marina Grubišić (pomoć pri izradi, neposredni voditelj)
• Committee member: Ksenija Markov (predsjednik povjerenstva)
• Committee member: Jasna Novak (član povjerenstva)
• Committee member: Blaženka Kos (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: 2023-09-22, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

U ovome radu proveden je uzgoj mikroalge Picochlorum sp. s ciljem optimizacije rasta i proizvodnje lipida u stresnim uvjetima izazvanih dodatkom NaCl (0 - 100 g L -1 ) i izostavljanjem izvora dušika i fosfora u hranjivoj podlozi. U istraživanju učinka rastućih koncentracija NaCl utvrđen je najveći udio lipida u suhoj tvari biomase (12,59 %) narasloj u hranjivoj podlozi sa 10 g L-1 NaCl, a najveća produktivnost rasta biomase mikroalge postignuta je uzgojem u podlozi sa 20 g L-1 NaCl (0,0211 g L-1 dan-1 ). U dvofaznom šaržnom uzgoju istražen je učinak stresa (2. faza rasta) izazvanog nakon rasta mikroalge u optimalnim uvjetima (1. faza rasta). Najveći udjel lipida (14,15 %) postignut je u kontrolnoj hranjivoj podlozi (f/2), dok je nedostatak izvora dušika rezultirao najslabijim rastom biomase. Također je proveden i fototrofni šaržni uzgoj mikroalge u barbotirajućoj koloni uz propuhivanje smjesom zraka i ugljikovog dioksida. Prihranom limitirajućim nutrijentima u prvoj fazi uzgoja omogućen je brz rast i nakupljanje biomase, dok je udrugoj fazi iscrpljivanje izvora dušika i fosfora potaknulo sintezu i nakupljanje lipida. Uz lipide (73,77 %) najzastupljenija makromolekula u suhoj tvari biomase su bili proteini (20,93 %).

Abstract (english)

In this paper, experiments were perfomed with the aim of optimising growth and lipid accumulation of microalgae Picochlorum sp. in stressful conditions via addition of NaCl (0 – 100 g L - 1 ) and phosphorus and nitrogen limitation. The culture grown in medium with 10 g L-1 NaCl resulted in the highest lipid (12.59 %) accumulation, while the highest productivity of biomass was achieved in the medium with 20 g L-1 NaCl (0.0211 g L-1 day-1 ). In the two-stage batch cultivation, the effect of stress (2nd phase) induced after providing optimal growth conditions (1st phase) for the microalgae was investigated. The control - f/2 medium resulted in the highest lipid content (14.15 %), while the nitrogen deficient medium had the most inhibitory effect on growth. Phototrophic batch cultivation in bubble column photobioreactor aerated with a mixture of air and carbon dioxide was also performed. Supplementation with limiting nutrients in the first phase of cultivation enabled rapid growth and accumulation of biomass, while the depletion of nitrogen and phosphorus sources in the second phase stimulated synthesis and accumulatuon of lipids. The most abundant macromolecules in the biomass were lipids (73,77 %), followed by proteins (20,93 %).

• Keywords: mikroalge; Picochlorum sp.; nutrijenti; salinitet; barbotirajuća kolona
• Keywords (english): microalgae; Picochlorum sp.; nutrients; salinity; bubble column bioreactor
• Language: croatian
• URN:NBN: urn:nbn:hr:159:972570
• 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: 2024-06-27 13:37:36