|
KMID : 0613820130230121486
|
|
Journal of Life Science
2013 Volume.23 No. 12 p.1486 ~ p.1494
|
|
|
Protease Properties of Protease-Producing Bacteria Isolated from the Digestive Tract of Octopus vulgaris
|
|
Liu Qing
Ren Pei
Piao Meizi
Yang Ji-Young
|
|
|
Abstract
|
|
|
|
A high protease-producing strain was isolated and identified from the digestive tract of octopus vulgaris by detecting a hydrolysis circle of protease and its activity. The strain was identified by morphology observation, biochemical experiments, and 16S rRNA sequence analysis. The protease obtained from the strain was purified by a three-step process involving ammonium sulfate precipitation, carboxy methyl-cellulose (CM-52) cation-exchange chromatography, and DEAE-Sephadex A50 anion-exchange chromatography. The properties of protease were characterized as well. The strain Bacillus sp. QDV-3, which produced the highest activity of protease, was isolated. On the basis of the phenotypic and biochemical characterization and 16S rRNA gene-sequencing studies, the isolate was identified as follows: domain: Bacteria; phylum: Firmicutes; class: Bacilli; order: Bacillales; family: Bacillaceae; and genus: Bacillus. The isolate was shown to have a 99.2% similarity with Bacillus flexus. A high active protease designated as QDV-E, with a molecular weight of 61.6 kDa, was obtained. The enzyme was found to be active in the pH range of 9.0-9.5 and its optimum temperature was 40℃. The protease activity retained more than 96% at the temperature of 50℃ for 60 min. Phenylmethylsulfonyl fluoride (PMSF) inhibited the enzyme activity, thus confirming that this protease isolated from Bacillus sp. QDV-3 is an alkaline serine protease. Metal ions, Mn²+ and Mg²+, were determined to enhance the protease activity, whereas Ba²+,Zn²+, and Cu²+ were found to inactivate the enzyme.
|
|
|
KEYWORD
|
|
|
Identification, intestinal bacteria, octopus vulgaris, protease, purification
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|