Optimiranje miksotrofnog i heterotrofnog uzgoja mikroalgi i ispitivanje učinkovitosti njihove bioflokulacije pomoću plijesni

master's thesis

• Title (english): Optimization of mixotrophic and heterotrophic microalgal cultivation and examination of fungal assisted bioflocculation efficiency
• Author: Ines Peremin
• Mentor: Mirela Ivančić - Šantek (mentor)
• 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: 2019-12-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Miksotrofna i heterorofna kultivacija mikroalgi temelj su aktualnih istraživanja zahvaljujući većoj produktivnosti sinteze biomase. U ovom radu proveden je niz eksperimenata s ciljem selekcije najprikladnijeg sastava podloge i uvjeta kultivacije za dobivanje vrijednih proizvoda. Istražen je rast na različitim izvorima ugljika te definiran učinak različitih molarnih omjera C:N na nakupljanje lipida i ugljikohidrata u biomasi uz različite procesne uvjete. Utvrđena je akumulacija rezervnih makromolekula pri višim omjerima C:N. Na temelju saznanja iz prethodno provedenih eksperimenata, proveden je heterotrofni šaržni uzgoj s pritokom supstrata mikroalge Chlorella vulgaris kojim je postignut prinos biomase od 20 g L-1 uz produktivnost 0,0747 g L-1 h-1. Tijekom uzgoja praćene su promjene sastava biomase. Troškovi izdvajanja biomase mikroalgi predstavljaju najveću prepreku komercijalizaciji biodizela proizvedenog ovom tehnologijom. Princip bioflokulacije kao alternativne tehnike izdvajanja stanica dokazan je uzgojem mješovite kulture s plijesnima Aspergillus niger, Aspergillus fumigatus i Mortierella isabellina.

Abstract (english)

Mixotrophic and heterotrophic microalgal cultivation is the basis of current research owing to higher biomass productivity. In this paper, a series of experiments was conducted with the aim of selecting the most suitable substrate composition and cultivation conditions to obtain valuable products. Growth on different carbon sources was investigated and the effect of different molar C:N ratios on the accumulation of lipids and carbohydrates in biomass was defined. The accumulation of storage macromolecules at higher C: N ratios were confirmed. Based on the previous findings, heterotrophic fed-batch cultivation of Chlorella vulgaris was carried out in bioreactor which yielded 20 g L-1 of biomass with productivity of 0,0747 g L-1 h-1. Changes in biomass composition were monitored during cultivation. The cost of biomass harvest is the biggest obstacle to the commercialization of microalgal biodiesel. The principle of biofloculation as an alternative cell harvesting technique has been demonstrated in the mixed culture with fungi Aspergillus niger, Aspergillus fumigatus and Mortierella isabellina.

• Keywords: mikroalge; Chlorella vulgaris; omjer C:N; lipidi; bioflokulacija
• Keywords (english): microalgae; Chlorella vulgaris; C:N ratio; lipids; bioflocculation
• Language: croatian
• URN:NBN: urn:nbn:hr:159:135791
• 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: 2019-12-31 09:31:31