Studies On Mutation Breeding And Application Of Enzyme Preparation Of Aspergillus Oryzae

The Aspergillus oryzae 3.4383 start strain mutated multiply by UV and EMS, a mutant strain UV-2'was obtained by separation, purification and cultivation.The mutant strains'activity of proteinase and cellulase was increased 3250 U/g and 1145 U/g to compare with the original (2526 U/g and 1145 U/g), the strain of UV-2'Aspergillus oryzae has good hereditary stability by inoculating 20 times.The mutation conditions:the distance is 28 cm,the time of irradiation is 60s with 30W ultraviolet lamp,the concentration of lithium chloide solution was 0.8%. The strain of UV-2'Aspergillus Oryzae was screened with high proteinase and cellulase activity. the proteinase and cellulase activity activity have improved 29% and 16% than the original strain.To determine the effect of the fermentation conditions and medium ingredinents on enzyme production,flask solid-state fermentation experiments were carried out.It was found that C/N source,activator,powder and water retio of the medium,fermentation temperature,fermentation time,pH,inorganic salt etc affected the enzymes formation in various degrees.The optimal medium compositionand fermentation conditions on proteinase and cellulase production were determined as: tween-80 0.24%, compounding ratio of solid state and water 5:3,pH7.5,as a result,high enzyme activity of 4572 U/g and 1923U/g was obtained after 84h culture at 40℃. Have probed out FeSO4 being able to restrain bacterial strain intensely producing enzyme , and KNO3 bacterial strain produce an enzyme improve greatly the effects of different nitrogen source and carbon source on the activity of proteinase and cellulose produced by Aspergillus oryzae UV-2 has been studied.Definited the best nitrogen source and carbon source were beancake and wheat bran,moreover the ratio of wheat bran:beancake in culture medium was 1:5 has been studied. Finally, test result does the effect coming to ascertain the synthetical factor producing an enzyme to bacterial strain the experiment consulting , designing orthogonal experiment with as said or narrated above respectively single factor. From this orthogonal experiment result we konow the most suit condition of the fermentation culture: beancake 60%,wheat bran 10%,KNO3 0.2%,tween-80 0.24%, compounding ratio of solid state and water 5:3,pH7.5,as a result,high enzyme activity of 4572 U/g and 1923U/g was obtained after 84h culture at 40℃.An experiment was conducted to study the effects of crude enzyme preparation supplementation on the performance of broilers fed corn-soybean diets and corn-wheat-soybean diets. Crude enzyme preparation supplementation reduced feed conversion rate (FCR) (P < 0.05). Average daily gain (ADG) and body weight (BW) wuggested that crude enere numerically increased (P < 0.10) for broilers fed the diet supplemented with Crude enzyme preparation. The digesta viscosity of corn-wheat-soybean diets decreased with the addition of crude enzyme preparation (P<0.05). Crude enzyme preparation supplementation increased the activity of protease significantly in intestinal content of broilers (P < 0.05), and the apparent ileal digestibility of protein tended to increase (P<0.10). Crude enzyme preparation supplementation had no effect on the activity of amylase in intestinal content of broilers and the apparent ileal digestibility of starch (P > 0.05).The results szyme preparation can improve growth performance in broilers.