School of Food Science and Engineering, Harbin Institute of Technology, Harbin, China.
Appl Microbiol Biotechnol. 2012 Mar;93(6):2335-43. doi: 10.1007/s00253-011-3790-5. Epub 2011 Dec 15.
In this study, we first tested the capacity for eight different salts as stress-mediated bioprocesses in the production of transglutaminase (TGase). A significant effect on the cell growth and TGase production was obtained with the highest yield of TGase being observed at 96 h of incubation (4.3 U/ml) when the basic medium was supplemented 0.10 M MgCl(2), as opposed to that observed with the basic medium control (2.1 U/ml at 120 h). Data from Western blot assays showed that transformation of pro-TGase to its mature enzyme occurred more rapidly in MgCl(2) medium. Furthermore, total protease, metalloprotease, and serine protease were also synthesized at a faster rate in the medium containing MgCl(2). The results demonstrate that MgCl(2) enhanced the production of key proteases involved in the activation of TGase biosynthesis. To explore the mechanism, viability assay was performed. The results show that MgCl(2) induced the mycelia differentiation, decreased cell growth rate, and stimulated cell death. We argue that TGase production was promoted by the stimulation of mycelium differentiation induced by MgCl(2) stress.
在这项研究中，我们首先测试了八种不同盐作为应激介导的生物过程在转谷氨酰胺酶（TGase）生产中的能力。当基本培养基中补充 0.10 M MgCl(2)时，与基本培养基对照（120 小时时为 2.1 U/ml）相比，观察到细胞生长和 TGase 生产有显著影响，孵育 96 小时时 TGase 的最高产量为 4.3 U/ml。Western blot 分析表明，在 MgCl(2)培养基中，原 TGase 向其成熟酶的转化发生得更快。此外，含 MgCl(2)的培养基中也更快地合成了总蛋白酶、金属蛋白酶和丝氨酸蛋白酶。结果表明，MgCl(2)增强了参与 TGase 生物合成激活的关键蛋白酶的产生。为了探讨其机制，进行了活力测定。结果表明，MgCl(2)诱导菌丝分化，降低细胞生长速度，刺激细胞死亡。我们认为，MgCl(2)应激诱导的菌丝分化刺激促进了 TGase 的产生。
