Study On Mixed Fermentation By Multi-strains Of Aspergillus Oryzae And Aspergillus Niger

As Aspergillus niger sprouts quickly compared with Aspergillus oyzae, cultured at 38℃for 4.5 hours by adding 0.4% of activating agent, the spore germination state of Aspergillus oyzae could be consistent with that of Aspergillus niger .The spore germination time of activating agent was1.5 hours shorter than that of non- activating agent at 32℃.The ability of soy sauce brewing of different Aspergillus oryzae and Aspergillus niger strains were analyzed. the protease activity of mature koji of Aspergillus oryzae 3.042 reached 0.9057 g/100g dry basis, its amino nitrogen renched 0.9131 g/100g fermentation, red index reached 2.35.all the three indexs were the best among the tested strains. The protease activity of tested strains were increased when adding activating agent during the koji making,as well as amino nitrogen and red index Both of the neutral and acid protease activity of Aspergillus niger 3.350 were higher thanthat of Aspergillus niger DF.In the combination of double strains of different strains, enzymatic activity of koji and amino nitrogen of Aspergillus oryzae 3.042: Aspergillus niger 3.350=8.5:1.5 reached 1.4294 g/100g dry basis and 0.7600 g/100g fermentation.It increased 18.80% and 9.48%. compared with Aspergillus oryzae 3.042 cultured alone. After adding activator,enzymatic activity of koji and amino nitrogen of Aspergillus oryzae 3.042:Aspergillus niger 3.350=8.5:1.5 reached 1.5922 g/100g dry basis and 0.7929 g/100g fermentation .It enhanced 15.52% and 10.55% more than Aspergillus oryzae 3.042 cultured alone.In the combination of double strains and three strains of the koji, compared with Aspergillus oryzae 3.042 added activator and cultured alone, enzymatic activity of koji and amino nitrogen of Aspergillus oryzae 3.042: Aspergillus niger 3.350=8.5:1.5 were enhanced by 15.52% and 10.55%, respectively.The results showed that enzymatic activity of koji and amino nitrogen reached 1.9470 g/100g dry basis and 0.5340 g/100g fermentation in soybean:wheat bran:water = 7.5:2.5:9 by adding 0.4% activator. At this ratio of material of Aspergillus oryzae 3.042:Aspergillus niger 3.350=9:1, amino nitrogen was the highest for 0.5885 g/100g fermentation after 5d fermentation by un-adding activator, In Aspergillus oryzae 3.042:Aspergillus niger 3.350=8.5:1.5, amino nitrogen was the highest for 0.5987 g/100g fermentation after 5d fermentation by adding activator...