Isolation,Identification and Enzymatic characteristics of a Alkaline High-temperature α-amylase-producing Strain

【Objective】To obtain the α-amylase producing strains,the samples were selected from brewhouse,flourmill and catsup-vinegar factory of Urumqi in 2007.【Method】The screening method used selected soluble starch plate and K-KI dyed,and enzyme activity was tested using the Dinitrosalicylic acid,and the identification of strain used VITEK-AMS.【Result】Nine α-amylase producing strains with relatively high enzyme activity were obtained.The enzyme activity of the strain A-1 is the highest among the 9 α-amylase-producing strains,which is 28.17 U/mL.The A-1 was identified as B.subtilis by VITEK-AMS.The enzymatic characteristics of the strain A-1 were studied and the result showed that the optimum temperature of the strain is 90℃ and the optimum pH value is 8.0.The optimum C source is the powder of corn,the optimum N source is the powder of soybean.【Conclusion】A-1 is a alkaline high-temperature α-amylase-producing strain.