Screening Of An Acid α-amylase Producing Strain And The Study On Its Enzymology Properties

Along with the raw materials of starch for industrial development, acidα-amylase industrial value of the constant attention of the people. There are more fungi than bacteria in the current screening results of acidα-amylase product strains . This topic wants to screening a bacteria strain to produce the acidicα- amylase . Three strongα- amylase vigor strains under the acidic condition were screenedfrom sewage sludge of starch factory and vinegar factory residue: B-1,B-5,B-6.Determines three strains crude enzyme optimum pH,only B-5 optimum pH in the acidic scope, belongs to acidα-amylase. The result of raw-starch hydrolysis show thatα-Amylase of B-5 has raw-starch hydrolysis ability. We chose B-5 for further study.B-5 was identified as Bacteria. Macerans from studying its cell shape, physiological and biochemical characteristics. B-5 produced acidα-amylase's zymology nature research demonstrated that the optimum temperature and optimum pH of the acidα-amylase is 70℃and pH 5.0. It has the very high stability between pH4.0-6.0,.But it's thermostability was not good enough.The raw enzyme liquor of B-5 was found only had one type of acidα-amylase after zymogram analysis. Purification of the crude enzyme ,detected by SDS-PAGE electrophoresis analysis showed that it has signal band. The molecular weight of the purified acidα-amylase is about 46.7 kD.