Biorefining problematic macroalgae for the production of high-value products

  • Angelos Fotiadis

Traethawd ymchwil myfyriwr: Traethawd Ymchwil DoethurolDoethur mewn Athroniaeth

Crynodeb

Macroalgal blooms are a global occurrence that have been affecting the stability of marine ecosystems with increasing frequency over the last decades. The genus of Ulva is characterised by annual blooms and rapid growth rate, commonly observed during the summer season. Although this phenomenon has serious environmental and socio-economic impacts, it could also provide sufficient quantities of potential feedstock for the production of multiple high-value added products. In this study, biomass consisting of bloom-forming species of Ulva, harvested from the site of Milford Haven, in south Wales, UK, has been evaluated as a source of high-value added products such as carotenoids, phenolic compounds, and polysaccharides. These natural products have been extracted from biomass harvested throughout the growing season using a range of hydrophobic and hydrophilic natural deep eutectic solvents (NADES) and characterised by spectrophotometric and chromatographic techniques. A novel model for sequential extraction of the selected high-value products has been proposed. Hydrophobic terpenoid-based NADES thymol-coumarin 2:1 (molar ratio) and hydrophilic choline chloride-lactic acid 1:2 (molar ratio) exhibited superior extraction efficiencies compared to conventional, reference organic solvents (e.g., methanol, water, and hexane) for the extraction of carotenoids and phenolic compounds/polysaccharides respectively. Highest carotenoid content was exhibited in biomass harvested in May (380 ± 0.01 μg g-1 dry weight) with three xanthophylls (lutein, neoxanthin, and lactucaxanthin) tentatively identified in the sample. Highest phenolic content was exhibited in biomass harvested in June (7.99 ± 0.07 mg GAE g-1 dry weight) quantified spectrophotometrically. Gravimetric quantification of purified extracts of ulvan polysaccharides indicated highest polysaccharide yields obtained from biomass harvested in July (39.05 ± 2.0 % dry weight). Fluctuations in the compositional profile of Ulva extracts were attributed to adaptation mechanisms of the biomass as a response to the changing environmental conditions. The findings of this project could provide information regarding the exploitation of macroalgal bloom biomass and the efficient incorporation of Ulva species into seaweed biorefineries, as well as the use of NADES for the optimisation of extraction processes.
Dyddiad Dyfarnu2022
Iaith wreiddiolSaesneg
Sefydliad Dyfarnu
  • Prifysgol Aberystwyth
GoruchwyliwrJessica Adams (Goruchwylydd) & Ana Winters (Goruchwylydd)

Dyfynnu hyn

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