Use of n-hexadecane as an oxygen vector to improve Phaffia rhodozyma growth and carotenoid production in shake-flask cultures.
OBJECTIVE
To identify beneficial oxygen vectors for Phaffia rhodozyma in liquid cultures, and to evaluate their use to improve the oxygen transfer and carotenoid production in the yeast cultures.


RESULTS
Several liquid hydrocarbons were tested as oxygen vectors for improving the yeast growth and carotenoid production in shake-flask cultures of P. rhodozyma. While all nontoxic organic liquids (Log P: > or =5.6) showed a positive effect, n-hexadecane was proved to be the most beneficial for the yeast growth and carotenoid production. The addition of 9% (v/v) n-hexadecane to the liquid medium at the time of inoculation was found to be optimal, increasing the carotenoid yield by 58% (14.5 mg l(-1) vs 9.2 g l(-1) in the control) and the oxygen transfer rate (OTR) by 90%.


CONCLUSIONS
The addition of n-hexadecane to shake-flask cultures of P. rhodozyma significantly improved the oxygen transfer in culture, thus increasing the carotenoid production.


CONCLUSIONS
Use of organic oxygen vectors such as n-hexadecane may be a simple and useful means for enhancing oxygen transfer and carotenoid production in liquid fermentation of P. rhodozyma.
Liu
Y S
YS
Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Wu
J Y
JY
D000473:Alkanes / Q000494:pharmacology*; D018533:Biomass; D019149:Bioreactors; D002338:Carotenoids / Q000096:biosynthesis*; D003470:Culture Media; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D010101:Oxygen Consumption; D015003:Yeasts / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism
D000473:Alkanes; D003470:Culture Media; D002338:Carotenoids; D000431:Ethanol; C007932:n-hexadecane