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Application of perfluorinated oxygen carrier in microwell cultures of Crypthecodinium cohnii cells

Magdalena Chmielewska

Abstract

Crypthecodinium cohnii belongs to the marine microorganisms, which have a great potential as producers of polyunsaturated fatty acids. Docosahexaenoic acid (DHA, ω – 3, 22:6) is one of the ω – 3 polyunsaturated acids, which is significantly important for human health. DHA supplementation helps the visual and neurological development of infants. It has also relevance to a drug for adults as neural and autoimmune diseases preventive compound. Traditionally, DHA is isolated from sea fishes. However, fishes are not the most efficient source of DHA due to problems with purification and poor organoleptic abilities of DHA acquired of them. Hence, marine microorganisms have become the most valuable source of DHA. Unfortunately, at present, DHA production by microbial methods is nearly irrelevant due to high costs of production. Thereby many methods improving the DHA content in the cell of C. cohnii are being developed. In this work, well–known and previously created screening systems were used for testing the influence of many additives on DHA productivity. Microorganisms were cultivated in microscale 24 – deep well plates. In order to improve oxygen transfer into the culture broth, perfluorodecalin was applied as oxygen vector. Moreover, cultivation was carried out in a previously established buffer system; it was compared the influence of MES and TRIS buffer on C. cohnii cultivation. Sampling and optical density measurements were automated; a liquid handling robot was applied. The most suitable additive for enhanced DHA productivity in C. cohnii was identified as being sodium acetate and acetic acid. It was possible to improve the DHA yield by 10 % achieving finally 30 % (v/v). Furthermore, the behaviour of a liquid PFD phase and gas exchange phenomenon was observed. It can be concluded that the cultivation has been performed without reaching oxygen limiting conditions. The applied screening system seems to be suitable for further investigations, especially for testing the time for additions, related to the physiological conditions of the cells. However, the pH shift after the addition of volatile fatty acids has to be kept in a range so that it will not affect the DHA productivity.
Record ID
WUT21ca97dd1a2841579c7bafa0562ef775
Diploma type
Master of Science
Author
Magdalena Chmielewska Magdalena Chmielewska,, Undefined Affiliation
Title in Polish
Zastosowanie perfluorowanego nośnika tlenu w miniaturowych hodowlach komórek Crypthecodinium cohnii
Supervisor
Maciej Pilarek (FCPE/DBBE) Maciej Pilarek,, Department of Biotechnology and Bioprocess Engineering (FCPE/DBBE)Faculty of Chemical and Process Engineering (FCPE)
Certifying unit
Faculty of Chemistry (FC)
Affiliation unit
Department of Biotechnology and Bioprocess Engineering (FCPE/DBBE)
Study subject / specialization
, Biotechnologia Przemysłowa
Language
(en) English
Status
Finished
Defense Date
23-10-2012
Issue date (year)
2012
Keywords in Polish
-
Keywords in English
-
Abstract in Polish
urn:pw-repo:WUT21ca97dd1a2841579c7bafa0562ef775