Molecular Identification of Protease - and Amylase -Secreting Bacillus subtilis SDYB -1 and Characterizations of Enzymes
Yue Shousong
Bian Fei
Dai Yunzhang
Wang Cuiping
Liu Guoxia
Zhang Yan
Chen Gao
Abstract：The complete 1 6S rDNA sequence of strain SDYB -1 with 1 548 bp was amplified and se-quenced.BLAST indicated that SDYB -1 was homology to Bacillus subtilis.A phylogenetic tree was construc-ted based on the homologies of 1 6S rDNA sequence of the strain with those of other relative bacteria species in the GenBank database.SDYB -1 gathered to one group with Bacillus subtilis.According to its morphological, physiological and biochemical characteristics and 1 6S rDNA sequence,the microorganism was identified and named as Bacillus subtilis SDYB -1 .The activity of protease increased rapidly after inoculating for 4 hours, and the value reached its maximum at 1 6 h then decreased sharply.The amylase activity increased continuous-ly with time,and reached the maximum value at 24 h then declined rapidly.The protease had the optimum temperature of 60℃,and was stable at 50℃.The optimum pH of protease was 8.5,and was stable at the same pH value.The amylase had the optimum temperature of 70℃,and showed high stability at 50℃,which maintained 97% activity after 50 minutes.The optimum pH of amylase was 5.6,and was stable at pH 4.6 ~7.0.
Keywords：Bacillus subtilis1 6s rDNAProteaseAmylase
Publication Date：2015-01-01
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：6( 54-59 )