环境因子对鳗弧菌生长和胞外蛋白酶表达的影响

Effect of culture conditions on the growth and extracellular protease expression of Vibrio anguillarum W1

鳗弧菌(Vibrio anguillarum)是一种水产动物的重要致病菌,鳗弧菌分泌的胞外蛋白酶是该菌的致病因子之一。研究了环境因子对鳗弧菌W-1生长及胞外蛋白酶表达的影响。结果表明,鳗弧菌的最适生长温度为28℃,菌体生长量在21h达到最高,胞外蛋白酶的活力在24h最高。在37℃培养时,菌体生长和酶活力显著降低;添加葡萄糖、蔗糖、麦芽糖等碳源物质均能显著促进菌体的生长,但对于胞外蛋白酶表达有明显抑制作用;1mmol/LEGTA对菌体的生长和胞外蛋白酶表达没有明显影响,而1mmol/L的EDTA强烈抑制鳗弧菌的生长及其胞外蛋白酶的表达。添加不同浓度的氨苄青霉素对菌体的生长及其胞外蛋白酶表达有明显的抑制作用。

Vibrio anguillarum is a pathogen of aquacutic animals. The extracellular protease has been considered as a putative virulence factor involved in pathogenic mechanism of the bacterium.In this study, the effects of culture conditions on the growth and extracellular protease production of V. anguillarum W1 were studied. The optimal temperature for bacterial growth and protease production was at 28℃. When the bacterium was cultured at 37℃, both cell growth and protease secretion were greatly reduced. Addition of glucose, sucrose, and maltose to the medium greatly increased the bacterial growth, but decreased secretion of the extracellular protease. 1mmol/L of EDTA could obviously prevent bacterial growth and protease activity, while addition of EGTA did not have obvious effect on the cell growth. The bacterial growth and secretion of the proteases were also inhabited by different amounts of ampicillin.