Breeding of Aspergillus Oryzae Strain for Producing Fructosyltransferase

In order to obtain Aspergillus oryzae strains that with a high of fructosyltransferase activity, Aspergillus oryzae SBB201 as the original strain was used to breed with genome shuffling technique. A candidate library had been built-up through the uv-lithium chloride compound mutation at conidia of Aspergillus oryzae. Mutant strains were chosen from the library as the initial strains for protoplast preparation and fusion mediated by PEG.After three rounds of genome recombination, a fusion mutant was obtained with its enzyme activity reached to178.90U/g. Compared with the ones of original strain (105.09U/g) , the enzyme activity of the fusion mutant had increased by 70.24%. From the assay results of fructosyltransferase activity in different generation, it was found that the fusion mutant RIII-7 showed a good of genetic stability.