ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-02252009-160954


Tipo di tesi
Tesi di dottorato di ricerca
Autore
FARALONI, CECILIA
URN
etd-02252009-160954
Titolo
Physiology of photosynthetic microorganisms, analysis and extraction of carotenoids with antioxidant activity
Settore scientifico disciplinare
CHIM/08
Corso di studi
SCIENZA DEL FARMACO E DELLE SOSTANZE BIOATTIVE
Relatori
Relatore Prof. Pistelli, Luisa
Relatore Dott. Torzillo, Giuseppe
Parole chiave
  • carotenoid
  • antioxidant microalgae
  • physiology
Data inizio appello
11/03/2009
Consultabilità
Non consultabile
Data di rilascio
11/03/2049
Riassunto
Carotenoids act as potential anti-oxidant, quenching excited energy of singlet oxygen and scavenging free radicals. It is well-known that under stress conditions photosynthetic organisms are able to synthesize large amount of carotenoids, which ca be considered as a natural source of antioxidant and anti-aging substances, i.e. astaxanthin, zeaxanthin, lutein, considered very powerful antioxidants. The microalgae Haematococcus pluvialis and Chlamydomonas reinhardtii are able to synthesize large amount of carotenoids and represent both a suitable source of antioxidant compounds. Under high light exposure and nutrient starvation both H. pluvialis and C. reinhardtii exhibited an increased capability to synthesize antioxidant carotenoids, such as astaxanthin, lutein and zeaxanhtin. In addition the screening of C. reinhardtii D1 protein mutants evidenced how the functionality of this protein was implicate in the photosynthetic activity of this microalga, promoting photoprotective responses at different level. In particular the mutant strains exhibited a strong induction of the xanthophylls cycle and lutein synthtesis under sulfur starvation and anaerobic conditions. The algal extracts exhibited an anti-inflammatory activity. The results indicated that these microalgae can represent a useful source of antioxidant compounds for application in human health.
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