Bacterial Sexuality at the Nanoscale

Area of Science:

• Microbiology
• Biotechnology
• Nanotechnology

Background:

• Bacterial gene transfer mechanisms are crucial in microbiology and biotechnology.
• Classical methods analyze cell populations, limiting insights into individual bacterial interactions.
• Nanotechnology offers novel approaches to study single-cell behaviors during gene transfer.

Purpose of the Study:

• To develop and utilize an atomic force microscopy (AFM) platform for studying DNA transfer between individual bacteria.
• To mechanically control and analyze plasmid transfer in Bacillus thuringiensis.
• To investigate the forces and molecular mechanisms underlying bacterial mating.

Main Methods:

• Development of an innovative atomic force microscopy (AFM) platform.
• Mechanical control and observation of DNA transfer between single donor and recipient bacteria.
• Analysis of adhesion forces and cell surface changes during plasmid transfer.

Main Results:

• Demonstrated strong adhesion forces (∼2 nN) between single Bacillus thuringiensis cells.
• Identified a pXO16 aggregation locus with two large surface protein genes mediating high adhesion forces.
• Showed that AFM can mechanically induce rapid plasmid transfer (<15 min) and cause significant cell surface alterations in transconjugant cells.

Conclusions:

• The developed single-cell AFM technology enables mechanical control of gene transfer in various bacterial species.
• This method provides insights into the molecular forces governing bacterial mating.
• The technology has potential applications in nanomedicine for designing antiadhesion compounds to combat bacterial pathogens.