Light-harvesting in bacteria exploits a critical interplay between transport and trapping dynamics

TL;DR

This paper analyzes how bacteria optimize light-harvesting by balancing excitation transfer and reaction center cycling, revealing different strategies under varying light conditions to maximize energy efficiency and protection.

Contribution

It provides a combined analytic and numerical framework explaining the adaptive architectures of bacterial light-harvesting membranes based on illumination intensity.

Findings

High light-intensity membranes use dissipation for protection.

Low light-intensity membranes channel unused light to reaction centers.

The study quantifies trade-offs in natural solar energy networks.

Abstract

Light-harvesting bacteria Rhodospirillum Photometricum were recently found to adopt strikingly different architectures depending on illumination conditions. We present analytic and numerical calculations which explain this observation by quantifying a dynamical interplay between excitation transfer kinetics and reaction center cycling. High light-intensity membranes (HLIM) exploit dissipation as a photo-protective mechanism, thereby safeguarding a steady supply of chemical energy, while low light-intensity membranes (LLIM) efficiently process unused illumination intensity by channelling it to open reaction centers. More generally, our analysis elucidates and quantifies the trade-offs in natural network design for solar energy conversion.