Using nanomaterials to increase the efficiency of chemical production in microbial cell factories: A comprehensive review

Microbes have proven to be robust workhorses for the large-scale production of many chemicals. Especially, high-value biochemicals (e.g., natural pigments, unsaturated fatty acids) that cannot be derived from fossil fuels, can be produced by engineered microbes. There is a growing interest in both academia and industry to find new technologies that can enhance the efficiencies of microbial cell factories and boost the circular bioeconomy. Rapid technological innovations, such as microbial genome editing and synthetic biology, have greatly advanced the production of chemicals in engineered microbes. Nanomaterial-based technologies that exploit the unique physiochemical properties of nano-scale materials (e.g., large surface area, excellent catalytic activity, tunable optical and electrical performance) have demonstrated great potential and attracted increasing attention. There are many studies showing that nanomaterials can assist microbes in the synthesis of chemicals by providing micronutrients, inducing anti-ROS responses, promoting gas-liquid mass transfer, immobilizing microbial cells and promoting electron transfer in electrosynthesis. Furthermore, the latest studies demonstrate that nanomaterials can be used to construct photocatalyst-microbe hybrids and achieve solar driven chemical production. In this review, we comprehensively summarize these advances and discuss the current gaps as well as future perspectives. With the rapid development of synthetic biology and nanotechnology, we believe more nanomaterial-based technologies will be developed and used to improve the productivity of microbial cell factories.