Alteromonas sp. SH-1균 유래의 α-agarase의 특성조사

• Published in: KSBB Journal Vol. 31; no. 2; pp. 113 - 119
• Main Authors: 이솔지(Sol-Ji Lee), 신다영(Da-Young Shin), 김재덕(Jae-Deog Kim), 이동근(Dong-Geun Lee), 이상현(Sang-Hyeon Lee)
• Format: Journal Article
• Language: Korean
• Published: 한국생물공학회 2016
• Subjects: 생물공학; Alteromonas sp. SH-1; agaropentaose; marine derived bacterium; α-Agarase; agarooligosaccharide; {\alpha}$-Agarase; Alteromonas sp; SH-1
• ISSN: 1225-7117; 2288-8268
• DOI: 10.7841/ksbbj.2016.31.2.113

A novel agar-degrading marine bacterium, SH-1 strain, was isolated from seashore of Namhae at Gyeongnam province, Korea. The SH-1 strain exhibited 98% similarity with Alteromonas species based on 16S rDNA sequencing and named as Alteromonas sp. SH-1. Alteromonas sp. SH-1 showed agarase activity of 348.3 U/L (1.67 U/mg protein). The molecular masses of the enzymes were predicted as about 85 kDa and 110 kDa by SDS-PAGE and zymogram. The enzymatic activity was optimal at $30^{\circ}C$ and the relative agarase activity was decreased as temperature increase from $30^{\circ}C$ and thus about 90% and 70% activities were shown at $40^{\circ}C$ and $50^{\circ}C$, respectively. The optimum pH was 6.0 for agarase activity in 20 mM Tris-HCl buffer and activities were less than 70% and 85% activity at pH 5.0 and pH 7.0, respectively, compared with that at pH 6. Agarase activity has remained over 90% at $20^{\circ}C$ after 1.5 hour exposure at this temperature. However, its activity was less than 60% at $30^{\circ}C$ after 0.5 h exposure at this temperature. The enzymes produced agarooligosaccharides such as agaropentaose and agarotriose from agarose, indicating that the agarases are ${\alpha}$-agarases. Thus, Alteromonas sp. SH-1 and its agarases would be useful for the industrial production of agarooligosaccharides which are known as having anticancer and antioxidation activities.