Ultra-high throughput droplet microfluidics for cultivation and functional screening of environmental microbial strains and consortia

Screening of microbial diversity is critical for discovering novel strains with enhanced biocatalytic capabilities. Traditional cultivation techniques often miss rare or slow-growing microorganisms, limiting our understanding of environmental microbiomes and their practical applications. Droplet-based microfluidics has emerged as a powerful platform for ultra-high-throughput screening of single cells or microbial consortia, encapsulated within microscale droplets that act as precisely controlled bioreactors. This tutorial review focuses on the application of droplet microfluidics for microbial cultivation and isolation, emphasizing advantages such as high throughput and the ability to perform functional assays on cultures originated from individual cells. Unlike previous reviews that broadly address microfluidic technologies or target specific applications like antibiotic resistance or enzyme discovery, we concentrate on protocols specifically designed for the clonal and parallel cultivation of microorganisms from environmental samples. Droplet microfluidics has already shown significant potential in environmental biotechnology, bioremediation, and microbial ecology. Reducing assay volumes and costs while increasing screening efficiency, positions droplet microfluidics as a key technology for the future of environmental microbiology research.