[2017.3.9]To reduce fermentation-associated wastewater discharge and the cost of wastewater treatment, which further reduces the total cost of DHA and ARA production, we first analyzed the composition of wastewater fromAurantiochytrium(DHA) andMortierella alpina(ARA) fermentation, after which wastewater recycling technology for these fermentation processes was developed. No negative effects of DHA and ARA production were observed when the two fermentation wastewater methods were cross-recycled. DHA and ARA yields were significantly inhibited when the wastewater from the fermentation process was directly reused. In 5-L fed-batch fermentation experiments, using this cross-recycle technology, the DHA and ARA yields were 30.4 and 5.13 g L−1, respectively, with no significant changes (P > 0.05) compared to the control group, and the water consumption was reduced by half compared to the traditional process. Therefore, this technology has great potential in industrial fermentation for polyunsaturated fatty acid production.

This research was financially supported by the National Key Research and Development Program, the National Natural Science Foundation of China, and the National High Technology Research and Development Program of China.

Figure: The route of the new wastewater cross-recycle technology for DHA and ARA fermentation

See the paper:

Xiaojin Song, Zengxin Ma, Yanzhen Tan, Huidan Zhang, Qiu Cui* (2017) Wastewater recycling technology for fermentation in polyunsaturated fatty acid production.Bioresour. Technol. 235,79-86. [PMID:28365352] [Full text (Publisher website)]