Assessing Normandy Soil Microbial Diversity for Antibacterial Activities Using Traditional Culture and iChip Methods

Area of Science:

• Microbiology
• Natural Products Chemistry
• Antimicrobial Resistance Research

Background:

• Uncultured microorganisms are a vital, yet underexplored, reservoir for novel antibacterial agents.
• Antimicrobial resistance (AMR) necessitates the discovery of new therapeutic compounds.
• Soil ecosystems harbor diverse microbial communities with potential for producing bioactive molecules.

Purpose of the Study:

• To enhance the recovery and identification of microorganisms from French soils.
• To screen recovered isolates for antibacterial activity against pathogenic bacteria.
• To explore the potential of these microorganisms as a source of new antibacterial natural products.

Main Methods:

• Employed both traditional culturing and isolation chip (iChip) techniques for microbial recovery.
• Identified isolates using 16S rDNA/ITS sequencing and MALDI-TOF mass spectrometry.
• Conducted antibacterial screening assays against target bacteria.

Main Results:

• Recovered 386 isolates across 6 phyla and 65 genera; 11 potentially novel species identified.
• The iChip method recovered a higher diversity of genera (47) compared to traditional methods (38).
• 85 isolates (22%) demonstrated antibacterial activity, with Streptomyces, Pseudomonas, and Bacillaceae being prominent producers.

Conclusions:

• The microbial collection from Normandy soils is a rich source of potential new antibacterial compounds.
• Both traditional and iChip methods are effective, with iChip showing advantages in microbial diversity.
• Further investigation of active isolates, including less common producers, could yield novel therapeutics.