Year: 2019
Type: dissertation
Abstract: Contemporary societies heavily rely on fossil fuels as their major energy source.Renewable energy sources, such biofuel, are desired to displace fossil fuels owing to concerns about climate change.In this respect, alternative bio-based technologies aim to supply fuels in a costeffective and sustainable manner while contributing to the reduction of greenhouse gases.The current generation of biofuel is completely dependent upon edible crop oil, which is derived from sources such as palm oil, resulting in serious complications to universal food-chain and biodiversity.Lipids from oleaginous microorganisms have great potential for displacing cropderived oils as biofuel substrates, but many restrictions prevent their economical and industrial application.The current project primarily addressed the key technical and environmental constraints concerning single cell lipid production from oleaginous yeasts related to sustainable feedstock, time-effective biomass and lipid yield, low-energy-demand for downstream processing as well as solvent-free processing as well as fermentative CO2 emission.Additional points contributing to thesis are from collaborations with different partners.With respect to sustainable feedstock, we attempted to utilize monosaccharides from marine macrophytes (Seagrass and Macroalgae) as feedstock for MO production.Among the studied samples, P. oceanica from the Mediterranean Sea and L. digitata from the western cost of Ireland displayed the best lipid productivity, exceeding the well-documented minimal nitrogen media.Additionally, the non-lipid yeast biomass (the yeast cell-wall) was applied, for first time, as a unique sugar source.The enzymatically produced yeast hydrolysate provided a sugar/nutrition rich medium for yeast fermentation, resulting in increasing biomass and lipid productivities.Acetic acid, as a sustainable yeast feedstock, was evaluated whether solo or in jointly with sugar.The monoauxic co-fermentation system enabled the simultaneous assimilation of sugar and acetic acid in rich-based medium.Via this co-fermentation, C. oleaginosus had a significantly high cell density (245 g L -1 ), lipid content (87% w/ d wbiomass) and lipid productivity (2.4 g L -1 h -1 ).This co-fermentation freed TGs biosynthesis from nitrogen-scarce needs, which subsequently avoided the classical diauxic fermentation and paved the way to the flash (short, approximately 45 h) or continuous fermentation mode.Microalgae, as another lipid producer, might be the optimal platform to assimilate CO2 from yeast fermentation.In this respect, the fatty acid profile and productivity were evaluated in Generation of Microbial Oil A Process Engineering Approach M . A . M a s r i ,
Author: Masri, Mahmoud
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: Verbundvorhaben Advanced Biomass Value: Entwicklung einer integrierten Verwertungskette zur Konversion von Algen und Hefe basierter Biomasse der dritten Generation zur Herstellung von Flugkraftstoffen, funktionalen Schmierstoffen und neuen Baustoffen, BioIndustrie2021: BioKatalyse2021: Lipide und oberflächenaktive Stoffe aus mariner Biomasse - LIPOMAR
OpenAlex ID: W7000714376