Georgina Benn

Gram-negative bacteria, such as E. coli, are intrinsically resistant to many antibiotics due to their outer membrane that surrounds the cell wall and cytoplasmic membrane, preventing access to intracellular targets. This has made Gram-negative bacteria a major priority for new antibiotic development. However, the design of drugs that cross the outer membrane is difficult. The complex mixture of lipoproteins, beta-barrel proteins and unique lipids form a dense, organised and formidable permeability barrier that we do not yet understand.

The goal of my work is to understand how the outer membrane is organised, how its mechanical properties are distributed, and how it is deformed during cell division. In previous work, we have shown that the outer membrane is much denser than previously thought: the cell is filled from pole to pole with an almost immobile lattice of proteins, held together by a thin layer of lipids that bridge neighbouring proteins. We also find a specific protein organises this lattice and connects the mechanical properties of the underlying cell wall to the outer membrane.

Understanding the outer membrane requires an interdisciplinary approach to span multiple length scales. Primarily, we use atomic force microscopy, super-resolution microscopy and bacterial genetics to investigate live bacteria at single nanometre resolution, larger scale organisation and population levels.