茂原链霉菌谷氨酰胺转氨酶合成与菌体形态分化的关系

目的：研究茂原链霉菌（Streptomyces mobaraensis）合成谷氨酰胺转氨酶（transglutaminase，TGase）与菌体分化之间的关系，以及TGase的生理功能。方法：以S. mobaraensis为出发菌株，通过向培养基中添加乙二胺四乙酸（ethylenediaminetetraacetic acid，EDTA）抑制TGase激活关键蛋白酶的活性从而调控成熟TGase的合成，同时利用激光共聚焦显微镜和扫描电镜观察发酵过程中菌体的活力和形态变化。结果：对照组随着TGase产量的升高，菌体生存活力呈先上升后下降的趋势，并且菌体表现出复杂的形态变化；实验组自加入EDTA后TGase产量不再升高，菌体生存活力也逐渐减弱，菌体形态分化滞后。结论：TGase的合成会影响茂原链霉菌生存活力及其形态分化。

XUE Hui,FU Ling,LI Hongbo,WANG Shumei,LIU Ning,ZHANG Lili

The purposes of the present study were to clarify the relationship between the morphological differentiation and transglutaminase (TGase) production Streptomyces mobaraensis, and to explore the physiological role of TGase in S. mobaraensis development. EDTA was added into the fermentation medium to inhibit the activities of the key proteases for TGase biosynthesis, and then the viability and morphological differentiation of the pellets were investigated using a confocal laser scanning microscope (CLSM) and a scanning electron microscope (SEM). The viability of S. mobaraensis pellets in the control group increased initially and decreased afterwards as the TGase activity increased, and the mycelia showed complex morphological changes. In the experimental group, a significant inhibition effect of EDTA was observed on TGase production, and the viability of S. mobaraensis pellets was decreased upon the addition of EDTA. In addition, mycelial morphological differentiation was delayed. These results suggest that TGase biosynthesis affects the viability of pellets and mycelial morphological differentiation of S. mobaraensis.