Investigation Of The Process About Fermentation, Purification And Application On A Maltogenic Amylase

Enzyme is a kind of biocatalytic activity substance which obtained from living organisms,enzymes are derived from animal and plant extraction and microbial fermentation.At present,the enzyme preparation from microorganism is the most abundant in industrialization,widely used in food,biomedicine,textile,washing,feed,bioenergy and other industries.In the field of food industry,enzymes play an important role in protein hydrolysis,flour product improvement,sugar conversion,fruit and vegetable processing,etc.In the field of flour improvement,α-amylase,xylanase,lipase,glucose oxidase,protease,glutamine transaminases and maltogenic amylase all play an important roles.By screening fermentation raw materials,three carbon sources(glucose,corn starch and glycerin),three nitrogen sources(yeast powder,corn pulp and soybean flour)and three inorganic salts(disodium hydrogen phosphate,dipotassium hydrogen phosphate and calcium chloride)were selected as a univariate gradient culture experiment.Finally,45g/L glucose,16g/L corn syrup and 6g/L calcium chloride were selected as the fermentation medium formula.On the basis of the preferred fermentation raw materials,the fermentation conditions(The optimal temperature was 41°C,p H 7.0,stirring speed 600 r/min,time 52 h,inoculation amount 9.5%)were optimized,the activity of Bacillus subtilis E619 to express maltogenic amylase reached 528 u/m L in 50 L fermenter.The powder samples were prepared by purifying the enzymatic liquid obtained from fermentation.The enzymatic characteristics and application evaluation of the enzyme showed that the optimum reaction temperature of maltogenic amylase purified from Bacillus subtilis E619 was 55-70℃,and the activity of the enzyme was completely lost when the temperature reaches 90℃.The maltogenic amylase can significantly delay the aging of bread products.Adding 200mg/kg of maltogenic amylase into bread,the softness of bread within 7days was similar to that of newly baked,and the hardness of bread without adding the enzyme was increased nearly 4.5 times on the 14 th day,the hardness of bread within 200mg/kg maltogenic amylase just increased 2 times.