The purpose of the study is to screen and identify amylase producing bacteria in the Black Lake in Yuli county

and to optimize the conditions of enzyme production. A high amylase producing strain HM-22 was screened from 43 strains of bacteria

has carried out morphological identification

molecular identification of 16S rDNA and optimization of enzyme production conditions were carried out. 43 strains of bacteria were isolated from 30 water

soil and mud samples in the Black Lake in Yuli County

and 14 strains producing amylase were screened out. The enzyme activity was determined by Yoo method

a strain with high enzyme activity was obtained and named as HM-22. By gram staining

colony morphology observation

physiological and biochemical tests

16S rDNA sequence alignment and the similarity of Bacillus tequilensis was 99.8%

belonging to the genus Bacillus. The optimization of enzyme production conditions of strain HM-22 was determined and the best condition for producing the enzyme is: the optimum temperature of amylase production was 40 ℃

the optimal carbon source is soluble starch

the optimal nitrogen source was beef extract

the optimum reaction pH was 6.0

the optimum culture time was 24 h. After optimization

the enzyme activity of strain HM-22 reached 147.53 U/mL from the initial activity of 122.45 U/mL

enzyme activity increased by 17%. The study provides a theoretical basis and reference for the screening of strains with high amylase activity in Xinjiang salt lake bacteria