Advances in biotechnological methods for genetic and metabolic engineering in Methylomonas sp. DH-1

Methylomonas sp. DH-1 is a Gram-negative methanotrophic bacterium that utilizes methane as a carbon source and presents a potential chassis for sustainable production of value-added metabolites from this greenhouse gas. Realizing this potential requires the development of reliable and tailored genetic engineering methodologies. Recent progress has expanded the molecular toolbox for this strain, including optimized transformation methods to overcome host restriction barriers and plasmid-free genome engineering using cell-penetrating Cre recombinase. In addition, a tunable promoter library for tunable transcriptional control and a synthetic small regulatory RNA platform for post-transcriptional modulation of gene expression have been established. Promising complementary engineering strategies, including adaptive laboratory evolution, synthetic consortia, and systems biology approaches can be used to improve strain robustness and metabolic performance. The review highlights these advances, along with metabolic engineering efforts that have enabled the synthesis of diverse value-added chemicals in Methylomonas sp. DH-1. Collectively, these developments provide the foundation for metabolic engineering and synthetic biology in Methylomonas sp. DH-1 and may inform the design of genetic tools in other methanotrophs.