Research on the Screening of Bacillus Strain Producing High-yielding Amylase

[Objective] The research on the screening of Bacillus strain with the ability in high-yielding amylase was conducted.[Method] The capacity of 10 Bacillus strains producing amylase was primarily tested with the staining method and finally determined with the chromogenic method of 3,5-dinitro-salicylic acid for the screening of the Bacillus strain with the ability in high-yielding amylase. [Results] 9 Bacillus strains had the capacity of amylase production,among which,two Bacillus subtilis strains: Pab03 and Pab02 showed the highest activity and the diameters of the chromatin circle of colony were 2.284 and 1.961,respectively.Under the premise of no fermentation as the optimal treatment,their enzyme activities were(31.331±0.985) and(21.521±1.390),respectively.As new type of digestive enzymes,they had a wide prospect in the application of feed additives.The strain coagulans Bacillus PSAF1and Bacillus subtilis PJK01 had the lowest ability in amylase-producing,which was(0.366±0.022) and(0.704±0.089),respectively.[Conclusion] Two Bacillus subtilis strains:Pab03 and Pab02 with the ability in high-yielding amylase-producing were successfully screened out.