Metabolomic analysis in Amycolatopsis keratiniphila disrupted the competing ECO0501 pathway for enhancing the accumulation of vancomycin.

Vancomycin is a clinically important glycopeptide antibiotic against Gram-positive pathogenic bacteria, especially methicillin-resistant Staphylococcus aureus. In the mutant strain of Amycolatopsis keratiniphila HCCB10007 Δeco-cds4-27, the production of ECO-0501 was disrupted, but enhanced vancomycin yield by 55% was observed compared with the original strain of A. keratiniphila HCCB10007. To gain insights into the mechanism of the enhanced production of vancomycin in the mutant strain, comparative metabolomics analyses were performed between the mutant strain and the original strain, A. keratiniphila HCCB10007 via GC-TOF-MS and UPLC-HRMS. The results of PCA and OPLS-DA revealed a significant distinction of the intracellular metabolites between the two strains during the fermentation process. 64 intracellular metabolites, which involved in amino acids, fatty acids and central carbon metabolism, were identified as differential metabolites. The high-yield mutant strain maintained high levels of glucose-1-phosphate and glucose-6-phosphate and they declined with the increases of vancomycin production. Particularly, a strong association of fatty acids accumulation as well as 3,5-dihydroxyphenylacetic acid and non-proteinogenic amino acid 3,5-dihydroxyphenylglycine (Dpg) with enhancement of vancomycin production was observed in the high-yield mutant strain, indicating that the consumption of fatty acid pools might be beneficial for giving rise to 3,5-dihydroxyphenylacetic acid and Dpg which further lead to improve vancomycin production. In addition, the lower levels of glyoxylic acid and lactic acid and the higher levels of sulfur amino acids might be beneficial for improving vancomycin production. These findings proposed more advanced elucidation of metabolomic characteristics in the high-yield strain for vancomycin production and could provide potential strategies to enhance the vancomycin production.