Investigation of the enhancement for Echinocandin B fermentation with methyl oleate from transcription level

Abstract

Echinocandin B (ECB) is the key precursor compound of the antifungal drug Anidulafungin. The effects of the five precursor amino acids on ECB biosynthesis were firstly investigated. It showed that although L-threonine was a main compound of the hexapeptide scaffold of ECB, exogenous addition of L-threonine had no significant effect on the increase of ECB fermentation titer. Meanwhile, the ECB fermentation titer with methyl oleate showed two times higher than that of the other carbon sources. Transcription level analysis of the key genes for ECB biosynthesis indicated that the gene an655543 related to L-threonine biosynthesis showed higher value during the fermentation process, therefore, the exogenous addition of L-threonine had no obvious affection. Furthermore, it indicated that the transcription level of gene ecdA might be the main restriction factor for the ECB biosynthesis. The study provided the research foundation for the modification of the ECB producing strains in the following work.