Secondary Metabolite Analysis of Phomopsis sp. LGT-5 Based on the Dual Guidance of Whole-Genome Sequencing and HPLC-Q-ToF-MS/MS

Abstract

Microorganisms produce a wealth of structurally diverse specialized metabolites with a remarkable range of biological activities. The Phomopsis sp. LGT-5 was obtained through tissue block and repeatedly crossed methods from Tripterygium wilfordii Hook. F. The antibacterial experiments of LGT-5 showed that it has high inhibitory activity against Staphylococcus aureus and Pseudomonas aeruginosa, and moderate inhibitory activity against Candida albicans. To research the generation of the antibacterial phenomenon of LGT-5 and provide support for further research and application, the whole genome sequencing (WGS) of LGT-5 was obtained by single-molecule real-time DNA sequencing platform Pacific Biosciences (PacBio) sequencing and Illumina paired-end sequencing. The final assembled LGT-5 genome is 54.79 Mb with a contig N50 of 290.07 kb; in addition, its secondary metabolites were detected through HPLC-Q-ToF-MS/MS. By comparing its MS/MS data, the secondary metabolites were analyzed based on visual network maps obtained on the Global Natural Products Social Molecular Networking (GNPS). The analysis results showed that the secondary metabolites of LGT-5 were triterpenes and various cyclic dipeptides.

Keywords: GNPS; Phomopsis sp. LGT-5; antibacterial; terpenoids; whole-genome sequencing.