The Screening Of Aspergillus Oryzae And Application Of Using Multi-strains During Koji Making

In this paper, soy sauce koji of Aspergillus oryzae strain as the research object, to a large domestic soy sauce production, and equipment based on the experimental conditions, the enterprise soy sauce koji of Aspergillus oryzae strains were screened and studied more strains of koji and single strain compared to the advantages of soy sauce koji, soy sauce fermentation stage, for businesses to choose koji bacteria in its actual production provides the basis and noted that a more detailed study of koji strains in the future direction.The main contents and conclusions are as follows:(1)Through enterprise koji of Aspergillus oryzae strain rejuvenation process colony morphology, casein plate transparent ring test, stability test and other screening passage, and when koji protease, amylase, cellulase enzyme activity and the size of soy sauce fermentation amino nitrogen, reducing sugar content of the small test screening process, as more excellent breeding a strain.(2)We studied the relationship between music into acidic protease, neutral protease, aminopeptidase, amylase, cellulase enzymes and fermented soy sauce index of amino nitrogen and reducing sugars. The results show that, in the course of koji acid protease, neutral protease, aminopeptidase activity and fermented soy sauce amino nitrogen content was positively correlated; amylase, cellulase content of reducing sugars and fermented soy sauce was positively correlated.The correlation between amino acid protease activity and amino nitrogen content of soy sauce:y= 0.0027x+0.5677(R2= 0.8765);The correlation between neutral protease activity and amino nitrogen content of soy sauce:y= 0.0002x+0.5292(R2= 0.9329);The correlation between aminopeptidase activity and amino nitrogen content of soy sauce:y= 0.0008x+0.7655(R2= 0.7794):The correlation between amylase activity and reducing sugar content of soy sauce:y= 0.0848x+4.2214(R2= 0.9496);The correlation between cellulase activity and reducing sugar content of soy sauce:y= 0.0096x+0.5294(R2= 0.7924);(3)Considering protease, amylase, cellulase enzyme called soy sauce made of amino nitrogen and reducing sugar and other indicators,The C, E and F Aspergillus strains were selected from the six strains,and the combination strains in koji making were carried out. The results show that the double strain mixing koji various enzymatic activity was significantly higher than the activity of a variety of single strain koji, wherein the acid protease activity of the double combination of strains in a single strain of more than 2 times, the most was 3.58 times;The activity of neutral protease in Double strains were a 1.26 times respectively to Single,and 1.5 times of aminopeptidase activity,1.04 times of cellulase activity. The protein utilization were all improved, the most was about 3.8 % compared with Single strains.(4)The conclusion of the bigger of the diameter of the circle of transparent than colony diameter,the better of the ability to produce the enzyme was not entirely correct,need further studies.