Batch, fed-batch and repeated fed-batch fermentation processes of the marine thraustochytrid Schizochytrium sp. for prod
- PDF / 444,746 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 19 Downloads / 231 Views
ORIGINAL PAPER
Batch, fed-batch and repeated fed-batch fermentation processes of the marine thraustochytrid Schizochytrium sp. for producing docosahexaenoic acid Liang Qu • Lu-Jing Ren • Guan-Nan Sun Xiao-Jun Ji • Zhi-Kui Nie • He Huang
•
Received: 15 December 2012 / Accepted: 2 May 2013 Ó Springer-Verlag Berlin Heidelberg 2013
Abstract Different fermentation processes, including batch, fed-batch and repeated fed-batch processes by Schizochytrium sp., were studied and compared for the effective DHA-rich microbial lipids production. The comparison between different fermentation processes showed that fed-batch process was a more efficient cultivation strategy than the batch process. Among the four different feeding strategies, the glucose concentration feed-back feeding strategy had achieved the highest fermentation results of final cell dry weight, total lipids content, DHA content and DHA productivity of 72.37, 48.86, 18.38 g l-1 and 138.8 mg l-1 h-1, respectively. The repeated fed-batch process had the advantages of reducing the time and cost for seed culture and inoculation between each fermentation cycles. The results of fermentation characteristics and lipid characterization of the repeated fed-batch process indicated that this repeated fed-batch process had promising industrialization prospect for the production of DHA-rich microbial lipids. Keywords Schizochytrium sp. Docosahexaenoic acid Feeding strategy Repeated fed-batch Introduction Schizochytrium sp., a kind of marine thraustochytrid, accumulated intracellular lipids in which the beneficial
L. Qu L.-J. Ren G.-N. Sun X.-J. Ji Z.-K. Nie H. Huang (&) State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, No. 5 Xinmofan Road, Nanjing 210009, People’s Republic of China e-mail: [email protected]
dietary docosahexaenoic acid (DHA, 22:6 n-3) forms 30–40 % of the total fatty acids [1, 2]. DHA, an essential x-3 long-chain polyunsaturated fatty acid, had attracted increasing attention for its various beneficial physiological functions in both adults and infants [3–6]. DHA-rich microbial lipids produced by Schizochytrium sp. was more suitable than fish oils for the use as food additives, because as the tradition commercial sources of DHA, fish oils had the disadvantages such as the high processing cost, seasonal variation of oil composition, declining fish stocks, marine pollution and poor oxidative stability [7]. Previous researches of Schizochytrium sp. producing DHA generally focused on the use of various raw materials [8–10], modulating nutritional and environmental factors [11–13], and optimizing fermentation parameters especially oxygen supply conditions [14–18]. Only a few studies focused on the fermentation processes (such as batch, fed-batch and continuous processes) for the effective fermentation process of Schizochytrium sp. producing microbial lipids rich in DHA [1, 19]. Fed-batch fermentation process, which had been extensively em
Data Loading...
