Unlocking Cryptic Metabolites with Mass Spectrometry-Guided Transposon Mutant Selection

Area of Science:

• Microbiology and Natural Product Discovery
• Genomics and Metabolomics

Background:

• Many secondary metabolite biosynthetic gene clusters (BGCs) remain uncharacterized due to low expression in lab cultures.
• Current methods like reporter-guided mutant selection (RGMS) are limited to single pathways and specific microorganisms.

Purpose of the Study:

• To develop a more global approach for discovering cryptic metabolites from diverse bacterial species.
• To overcome limitations of existing methods for identifying compounds from unexpressed BGCs.

Main Methods:

• Utilized untargeted metabolomics and transposon mutagenesis for a broad analysis of secondary metabolism.
• Employed self-organizing map analytics and imaging mass spectrometry for metabolite identification and characterization.

Main Results:

• Successfully identified and characterized seven cryptic metabolites from two *Burkholderia* species.
• Demonstrated a global read-out of secondary metabolism across numerous mutants.

Conclusions:

• The developed methodology enables the discovery of products from cryptic BGCs in a phylogenetically diverse range of bacteria.
• This approach significantly expands the understanding of bacterial secondary metabolism and its regulation.