Microbial production of medium chain fructooligosaccharides by recombinant yeast secreting bacterial inulosucrase

• Published in: Enzyme and microbial technology 2019-11, Vol.130, p.109364-109364, Article 109364
• Main Authors: Ko, Hyunjun, Bae, Jung-Hoon, Sung, Bong Hyun, Kim, Mi-Jin, Park, Hyun-Ju, Sohn, Jung-Hoon
• Format: Article
• Language: English
• Subjects: Direct fermentation; Fermentation; Fructooligosaccharides; Hexosyltransferases - metabolism; Industrial Microbiology; Inulosucrase; Lactobacillus reuteri - enzymology; Lactobacillus reuteri - genetics; Medium chain; Oligosaccharides - metabolism; Recombination, Genetic; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Sucrose - metabolism
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2019.109364

•A recombinant yeast strain was developed for production of fructooligosaccharides.•Truncated inulosucrase was secreted by recruiting an optimal secretion signal.•The highest conversion yield was 85.6% from 300 g/L sucrose by direct fermentation.•The highest titer was 152.6 g/L from 400 g/L sucrose by direct fermentation.•Medium chain FOS with DP around 2–20 was mainly produced. A high yielding and straightforward production system of fructooligosaccharide (FOS) was developed for industrial production of prebiotics. To increase conversion yield of FOS from sucrose, recombinant yeast secreting inulosucrase from Lactobacillus reuteri (LrInu) were constructed. Efficient secretion of LrInu was achieved by truncation of both amino- and carboxy-termini (LrInuΔNC) and by introducing an optimal secretion signal. The recombinant yeast produced 220 U/mL of recombinant LrInuΔNC into culture medium during fed-batch fermentation. By direct fermentation of recombinant yeast in medium containing sucrose, 128.4 g/L of FOS was produced with 85.6% conversion yield from 300 g/L sucrose, and the highest titer was 152.6 g/L from 400 g/L sucrose. The degree of polymerization of generated FOS was 2–20 indicating medium chain (mcFOS) range. This is the first report of industrially applicable production of mcFOS by recombinant yeast secreting bacterial inulosucrase.