Liberti, Davide (2023) Microalgae as biorefinery: development of processes for the green extraction of high added value antioxidants. [Tesi di dottorato]

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Item Type: Tesi di dottorato
Resource language: English
Title: Microalgae as biorefinery: development of processes for the green extraction of high added value antioxidants
Creators:
Creators
Email
Liberti, Davide
davide.liberti@unina.it
Date: 7 March 2023
Number of Pages: 308
Institution: Università degli Studi di Napoli Federico II
Department: Biologia
Dottorato: Biotecnologie
Ciclo di dottorato: 35
Coordinatore del Corso di dottorato:
nome
email
Moracci, Marco
marco.moracci@unina.it
Tutor:
nome
email
Monti, Daria Maria
UNSPECIFIED
Date: 7 March 2023
Number of Pages: 308
Keywords: Microalgae; Biorefinery; Antioxidant activity
Settori scientifico-disciplinari del MIUR: Area 05 - Scienze biologiche > BIO/10 - Biochimica
Date Deposited: 20 Mar 2023 10:49
Last Modified: 10 Apr 2025 14:11
URI: http://www.fedoa.unina.it/id/eprint/15187

Collection description

Nowadays, the strategy of biorefinery perfectly fits with the circular bioeconomy concept and microalgae can be considered excellent candidates for their use in biorefinery approaches. Indeed, microalgae are a reliable source of natural compounds with different biological activities, they perform carbon capture and can grow in lands which do not compete with food production. The aim of the present PhD project was the complete exploitation of Porphyridium cruentum culture to obtain different high value products in a cascade approach. Sulphated exopolysaccharides (s-EPSs) were isolated from the culture medium and a chemical characterization was obtained. Different procedures to harvest the biomass were compared, and biomass storage was analyzed in the context of phycoerythrin (PE) yield. Phycoerythrin isolation was defined upon evaluation of different techniques. The obtained purity grade of the protein was so high that its X-ray structure was determined at 1.60 Å resolution and the protein sequence was determined. Then, carotenoids and lipids were extracted from the residual biomass in two sequential steps and a complete chemical characterization was achieved. In-vitro and cell-based assays were performed to assess the biological activities of these compounds. The s-EPSs, thanks to the presence of sulphate groups, showed biocompatibility on immortalized eukaryotic cell lines and a high antioxidant activity on cell-based systems. PE showed powerful antioxidant activity both in vitro and on cell-based systems, but its purification is mandatory for its safe use. Finally, both molecules showed anti-inflammatory activity comparable to that of Ibuprofen and helped tissue regeneration. The obtained results could boost the industrial utilization of P. cruentum offsetting the high downstream processes cost. Moreover, the simultaneous microalgae culture valorization and carbon capture can contribute to the sustainable expansion of microalgae market.

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