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2 April - June 2015 |
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High cell density cultivation for docosahexanoic acid production
of Schizochytrium sp. BCC 25505
Wai Prathumpai*, Nuntida Sahoch-atiraklap and Kanokarn Kocharin
National Center for Genetic Engineering and Biotechnology, National Science and Technology
Development Agency, 113 Thailand Science Park, Paholyothin Rd., KlongNueng, KlongLuang,
PathumThani 12120, Thailand
*Corresponding author: wai.pra@biotec.or.th
Abstract
Docosahexanoic acid (22:6 n-3; DHA) is a polyunsaturated fatty acid that is essential
for functional development and maintenance of human brain and is also involved in the
prevention of cardiovascular diseases, improving neural and retinal development in infants.
Schizochytrium sp. BCC 25505, a marine protist, can produce DHA at high yield.In this
study, biomass and DHA production of this marine protist were carried out to avoid glucose
repression and nitrogen limitation using high cell density cultivation technique. The use
of high glucose concentration resulted in a slow growth rate and low biomass concentration.
By employing central composite design and by pulsing 40 g.L-1 glucose at a time yielded
maximum biomass (77.3 g.L-1) and DHA (18.5 g.L-1) productions.Theoptimal conditions
for maximizing DHA production ofSchizochytrium sp. BCC 25505 calculated using Design
expert software were validated in a 5L bioreactor cultivation, yielding at 97 h a maximum
concentration of biomass and docosahexanoic acid of 70.8 and 14.1 g?L-1 respectively.
This was further scaled up in 300 L bioreactor and 115.9 g.L-1 biomass, 15.0 g.L-1 DHA at
119 h were obtained. This optimal fermentation process can provide a low cost production
of DHA, which can be used in industrial scale.
Keywords: docosahexanoic acid, Schizochytrium sp, Plackett-Burman design, Central
composite design, Single cell oil.
