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

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.