雪白白僵菌红色素的初步鉴定及其与环孢菌素A对底物缬氨酸的竞争

Identification of red pigment and it’s biosynthesis depending on co-substrate valine in cyclosporine A production

摘要:

【目的】分离鉴定雪白白僵菌红色素，分析红色素与环孢菌素A对底物缬氨酸的竞争和相互影响。【方法】对红色素进行分离纯化，利用UV、IR和ESI-MS对红色素进行初步鉴定。采用缬氨酸分批补料培养，通过控制溶氧水平，以及添加红色素，分析红色素与环孢菌素A合成之间的竞争关联及相互影响。【结果】经鉴定，雪白白僵菌红色素分子式为C15H10O5，推测为含有芳环结构的蒽醌类化合物。在补加缬氨酸和高DO条件下，环孢菌素的产量高于低DO水平，相反红色素在低DO条件下合成量大于高DO水平。在不补加缬氨酸条件下，实验结果与补加缬氨酸培养一致，但是红色素和环孢菌素A的产量都显著降低。进一步添加外源纯化的红色素时，随着添加量的增加出现了环孢菌素A合成先减弱后增加的变化。【结论】发现并证实了雪白白僵菌红色素与环孢菌素A合成都以缬氨酸为共同底物，但两者的途径又相互 独立。

Abstract:

[Objective] To identify red pigment produced by Beauveria nivea and further research the relationship between red pigment and cyclosporine A (CysA). [Methods] the red pigment was separated and identified by spectrum analysis including UV, IR and ESI-MS. the yield of red pigment and CysA was measured at different cultivation conditions, respectively. the internal relationship between the biosynthesis of red pigment and CysA was examined by adding the purified red pigment. [Results] The molecular formula of red pigment was confirmed as C15H10O5 which contains benzene ring and aromatic ring ketone structure and belongs to anthraquinones. The further experiments revealed that the negative relationship dominated in the biosynthesis between CysA and red pigment. The case with higher productivity of CysA due to valine feeding and high DO must be lower red pigment yield. Especially, the foreign red pigment added during the cultivation would result in down first and then up for CysA production. [Conclusion] The red pigment produced by Beauveria nivea was firstly separated and identified. Importantly, the research results verified that the red pigment and CysA had independent biosynthesis pathways which shared with the same substrate valine.