Protoplast preparation and regeneration of Aspergillus oryzae 3.042

The factors affecting protoplast formation and regeneration of Aspergillus oryzae 3.042 were studied including composition of enzyme mixture,enzymolysis temperature,enzymolysis time,osmotic pressure stabilizer,medium composition,culture methods and so on.The appropriate method for protoplast formation and regeneration were developed.A.oryzae 3.042 was cultured in Czapek liquid medium for 10 h,then the mycelia were gathered by centrifugation and digested by enzyme mixture consisting of 0.8 mol/L NaCl,3% lywallzyme,1% cellulase,1% snailase and 0.5% lysozyme at 30℃ for 4~6 h,followed by the regeneration on solid medium containing 0.8 mol/L NaCl by double-layers cultivation.A regeneration rate of 70% was achieved.This study provided a new method to screen good strains for sauce production by protoplast technology.