Characterization of a Fibrinolytic Enzyme Secreted by Bacillus velezensis BS2 Isolated from Sea Squirt Jeotgal

• Published in: Journal of microbiology and biotechnology Vol. 29; no. 3; pp. 347 - 356
• Main Authors: Yao, Zhuang, Kim, Jeong A, Kim, Jeong Hwan
• Format: Journal Article
• Language: English
• Published: Korea (South) 한국미생물·생명공학회 28.03.2019
• Subjects: 생물학; salt tolerance; sea squirt jeotgal; fibrinolytic activity; Bacillus velezensis
• ISSN: 1017-7825; 1738-8872
• DOI: 10.4014/jmb.1810.10053

sp. BS2 showing strong fibrinolytic activity was isolated from sea squirt (munggae) jeotgal, a traditional Korean fermented seafood. BS2 was identified as by molecular biological methods. BS2 grows well at 15% NaCl and at 10oC. When B. velezensis BS2 was cultivated in TSB broth for 96 h at 37°C, the culture showed the highest fibrinolytic activity (131.15 mU/µl) at 96 h. Three bands of 27, 35 and 60 kDa were observed from culture supernatant by SDS-PAGE, and fibrin zymography showed that the major fibrinolytic protein was the 27 kDa band. The gene ( ) encoding the major fibrinolytic protein was cloned, and overexpressed in heterologous hosts, WB600 and BL21 (DE3). transformant showed 1.5-fold higher fibrinolytic activity than BS2. Overproduced AprEBS2 in was purified by affinity chromatography. The optimum pH and temperature were pH 8.0 and 37°C, respectively. K and V were 0.15 mM and 39.68 µM/l/min, respectively, when N- -Ala-Ala-Pro-Phe-pNA was used as the substrate. AprEBS2 has strong α-fibrinogenase and moderate β-fibrinogenase activity. Considering its high fibrinolytic activity, significant salt tolerance, and ability to grow at 10°C, BS2 can be used as a starter for jeotgal.