Supervisors info:
Α. ΟΙΚΟΝΟΜΟΥ-ΑΜΙΛΛΗ, Ομότιμη Καθηγήτρια, Τμήμα Βιολογίας ΕΚΠΑ
Μ.ΚΡΟΚΙΔΑ, Καθηγήτρια, Χημικών Μηχανικών ΕΜΠ
Δ.ΧΑΤΖΗΝΙΚΟΛΑΟΥ, Αναπληρωτής Καθηγητής, Τμήμα Βιολογίας ΕΚΠΑ
Summary:
The purpose of this study is to maximize β-carotene production by Greek strains of the genus Dunaliella using photobioreactors. The main objective of this effortis to select strains from Greece suitable for use in the carotenoid industry, able to replace imported strains, and improve the productivity and the cost of production.
Seven Greek strains of the genus Dunaliella isolated from the Mesolongi salt ponds and the Great Emvolon salt lake of Thessaloniki, which are kept in monocultures at the Strain Bank of the Department of Taxonomy and Ecology of the Faculty of Biology of NKUA. These strains (D2, D5, D6, D8, D30, D31, D32) were tested for their β-carotene productivity in small scale cultures (250mL), the most efficient ones being tested on a larger scale using photobioreactors. Lastly, mass culture protocols were developed for their sustainable industrial exploitation in large scale crops, thus contributing to the development of know-how in our country.
During this study four main stages were executed:
1. Usage of four different formulations of nutrients and three different concentrations in the final culture.
2. Application of the most efficient combinations of strains and nutrients on a larger scale using photobioreactors to confirm their efficacy.
3. Usage of increased salinity and different concentrations of nitrogen in nutrients as mechanisms of increasing the stress of microalgae so as to maximize β-carotene production.
4. Application of two different approaches in order to develop a protocol for the most efficient cultivation of studied microalgae for the production of β-carotene.
Two strains (D31 and D30) stood out in terms of productivity during all phases as mentioned above, which were even comparable and in many cases larger than those reported in the literature. Moreover, the protocols developed and tested in these two strains gave very promising results for their use in the industry on large scale crops.
Finally, this work opens up new perspectives for the exploitation of these strains at the industrial level but also for further investigation of both the mechanism of carotenogenesis in the targeted genus and strains, photobioreactors and protocols used by the industry. These results could play a crucial role in the development of this industry in our country.
Keywords:
Algae, β-carotene, photobioreactors, biotechnology, applied phycology
