Efficient production of levan using a recombinant yeast Saccharomyces cerevisiae hypersecreting a bacterial levansucrase. (1st November 2019)

• Record Type: Journal Article
• Authors: Ko, Hyunjun; Bae, Jung-Hoon; Sung, Bong Hyun; Kim, Mi-Jin; Kim, Chul-Ho; Oh, Baek-Rock; Sohn, Jung-Hoon
• Is Part Of: Journal of industrial microbiology & biotechnology. Volume 46:Number 11(2019)
• Page Start: 1611
• Page End: 1620
• Publication Date: 2019-11-01
• Subjects: Levan -- Saccharomyces cerevisiae -- Levansucrase -- Recombinant protein expression -- Direct fermentation; Industrial microbiology -- Periodicals; 660.62
• DOI: 10.1007/s10295-019-02206-1
• Languages: English
• ISSNs: 1367-5435

Abstract

Abstract: Levan is a fructose polymer with diverse applications in the food and medical industries. In this study, levansucrase from Rahnella aquatilis (RaLsrA) was hyper-secreted using a Saccharomyces cerevisiae protein secretion system. An optimal secretion signal, a translation fusion partner (TFP) containing an N-terminal 98 amino acid domain from a mitochondrial inner membrane protein, UTH1, was employed to secrete approximately 50 U/mL of bioactive RaLsrA into culture media with 63% secretion efficiency by fed-batch fermentation. Although the purified RaLsrA was useful for enzymatic conversion of high-molecular-weight levan of approximately 3.75 × 10 6 Da, recombinant yeast secreting RaLsrA could produce levan more efficiently by microbial fermentation. In a 50-L scale fermenter, 76-g/L levan was directly converted from 191-g/L sucrose by recombinant yeast cells, attaining an 80% conversion yield and 3.17-g/L/h productivity. Thus, we developed a cost-effective and industrially applicable production system for food-grade levan.