Using Molecular Networking for Microbial Secondary Metabolite Bioprospecting

Area of Science:

• Marine microbiology
• Natural product chemistry
• Biogeography

Background:

• Oceans are underexplored sources of bacteria producing novel secondary metabolites.
• Actinomycetes are known for diverse metabolites with broad biological activities.
• Investigating geographic influence on bacterial secondary metabolism is crucial.

Purpose of the Study:

• Characterize spore-forming bacteria from Scottish and Antarctic sediments.
• Assess the impact of isolation location on secondary metabolite profiles.
• Identify potential novel bioactive compounds from marine bacteria.

Main Methods:

• Isolation and characterization of 85 bacterial strains from marine sediments.
• Chemical investigation of 38 morphologically distinct isolates.
• High-resolution mass spectrometry/mass spectrometry (HR-MS/MS) based molecular networking of fermentation extracts.

Main Results:

• Bacterial isolates belonged to Firmicutes and Actinobacteria phyla, primarily Bacillus and Streptomyces genera.
• Antarctic and Scottish isolates produced distinct metabolite profiles, with only 8% shared compounds.
• Molecular networking revealed over 3500 parent ions, with 40-42% unique to each location.
• Seven extracts exhibited bioactivity against colon adenocarcinoma cells.

Conclusions:

• Bacterial secondary metabolite production is significantly influenced by geographic origin.
• Marine sediments, particularly from understudied regions, harbor diverse and novel chemical entities.
• These findings underscore the potential of marine bacteria for discovering new bioactive compounds.