Enhanced production of fructosyltransferase in Aspergillus oryzae by genome shuffling

Biotechnol Lett. 2017 Mar;39(3):391-396. doi: 10.1007/s10529-016-2254-5. Epub 2016 Nov 16.

Abstract

Objective: To breed Aspergillus oryzae strains with high fructosyltransferase (FTase) activity using intraspecific protoplast fusion via genome-shuffling.

Results: A candidate library was developed using UV/LiCl of the conidia of A. oryzae SBB201. By screening for enzyme activity and cell biomass, two mutants (UV-11 and UV-76) were chosen for protoplast fusion and subsequent genome shuffling. After three rounds of genome recombination, a fusion mutant RIII-7 was obtained. Its FTase activity was 180 U g-1, approximately double that of the original strain, and RIII-7 was genetically stable. In fermentation culture, FTase activity of the genome-shuffled strain reached a maximum of 353 U g-1 using substrate-feeding method, and this value was approximately 3.4-times higher than that of the original strain A. oryzae SBB201.

Conclusions: Intraspecific protoplast fusion of A. oryzae significantly enhanced FTase activity and generated a potentially useful strain for industrial production.

Keywords: Aspergillus oryzae; Fructo-oligosaccharides; Fructosyltransferase; Genome shuffling; Protoplast fusion.

MeSH terms

  • Aspergillus oryzae / drug effects
  • Aspergillus oryzae / enzymology*
  • DNA Shuffling / methods*
  • Fermentation / drug effects
  • Genome, Fungal*
  • Genomic Instability
  • Hexosyltransferases / biosynthesis*
  • Membrane Fusion / drug effects
  • Mutagenesis / genetics
  • Mutation / genetics
  • Protoplasts / drug effects
  • Protoplasts / metabolism
  • Regeneration / drug effects
  • Sucrose / pharmacology

Substances

  • Sucrose
  • Hexosyltransferases
  • inulosucrase