Screening of a high-temperature α-amylase-producing strains and optimization of its fermentable condition

16 α-amylase-producing strains were screened from soil and waste water.C-1 has the highest enzyme activity among such 16 strains.This strain can grow well under high temperature of 50 ℃.The activity of α-amylase produced by of C-1 strain is about 20 U/mL under liquid fermentation under 40 ℃,pH 6.0.C-1 was identified as B.subtilis C-1 through normal screening and analysis of 16S rDNA gene.Subsequently,the fermentation condition of B.subtilis C-1 were optimized and it's enzymology property were studied.