Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, No.18, Chaowang Road, Hangzhou, 310014, People's Republic of China.
Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, People's Republic of China.
Bioprocess Biosyst Eng. 2020 Oct;43(10):1801-1811. doi: 10.1007/s00449-020-02371-z. Epub 2020 May 13.
This study aimed to express an inulinase gene from the yeast Kluyveromyces marxianus (KmINU) in Aurantiochytrium sp. and realized one-step utilization of inulin resource for DHA production without any chemical pretreatment. An expression cassette with a length of 6052 bp for expressing the inulinase gene was constructed by a fast two-step PCR method and then was transferred into the Aurantiochytrium sp. cells. The Aurantiochytrium sp. recombinant T39 was selected with an inulinase activity up to 50.1 U/mL in 72 h. In a 5-l fed-batch fermentation, as high as 148.9 g/L of inulin was directly used within 120 h, and only 1.2 g/L of total sugar was left in the medium at the end of fermentation. The biomass of 51.4 g/L with a lipid content of 69.2% DCW and a DHA yield of 14.9 g/L was obtained.
本研究旨在通过酵母克鲁维酵母（KmINU）中的菊粉酶基因在雨生红球藻中表达，并实现一步利用菊粉资源生产 DHA，无需任何化学预处理。通过快速两步 PCR 方法构建了一个长 6052 bp 的表达盒，用于表达菊粉酶基因，然后将其转入雨生红球藻细胞中。雨生红球藻重组菌 T39 在 72 h 内的菊粉酶活性高达 50.1 U/mL。在 5 L 补料分批发酵中，在 120 h 内直接使用了高达 148.9 g/L 的菊粉，发酵结束时培养基中仅残留 1.2 g/L 的总糖。获得了 51.4 g/L 的生物量，其干重（DCW）的脂质含量为 69.2%，DHA 产量为 14.9 g/L。
