# Photovoltaic Microorganism Hybrid Systems for Enhanced Polyhydroxybutyrate Synthesis Through Material Design and Energy Mass Transfer Mechanisms

## TL;DR

This review explores how combining photosensitive materials with microorganisms can improve the production of a biodegradable polymer called PHB, which could replace traditional plastics.

## Contribution

The paper provides a systematic review of photosensitive materials and their role in enhancing PHB synthesis through efficient electron transfer and microbial interactions.

## Key findings

- Photosensitive materials like g-C3N4 and CdS can boost intracellular reducing power in microorganisms, enhancing PHB synthesis.
- Material composition and structure significantly influence electron transfer efficiency and biocompatibility in hybrid systems.
- Current challenges include optimizing light energy conversion and transmembrane electron transport in these systems.

## Abstract

Polyhydroxybutyrate (PHB), as a biodegradable and green polymer, holds significant potential for replacing traditional petroleum-based plastics. However, its production efficiency and cost remain bottlenecks limiting large-scale application. In recent years, hybrid systems constructed from photosensitive nanomaterials and microorganisms have provided a novel pathway for enhancing PHB synthesis efficiency. These systems augment the supply of intracellular reducing power through efficient photo-generated electron injection, thereby driving microbial carbon fixation and PHB anabolic metabolism. This review systematically summarizes the mechanisms and performance of various types of photosensitive materials (including g-C3N4, CdS, polymer dots, etc.) in regulating PHB synthesis in microorganisms, such as Cupriavidus necator H16. It focuses on the influence of material composition, structure, energy band characteristics, and their interfacial interactions with microorganisms on electron transfer efficiency and biocompatibility. Furthermore, the article outlines the current challenges faced by these hybrid systems in key energy and mass transfer processes, including light energy conversion, transmembrane electron transport, and NADPH regeneration. It also prospects the design principles of novel bio-inspired multi-level heterojunction materials and their application potential in constructing efficient “material microbe” collaborative synthesis systems. This review aims to provide a material-level theoretical foundation and design strategies for developing high-performance and sustainable light-driven biomanufacturing technologies for PHB.