Passive Droplet Microfluidic Platform for High-Throughput Screening of Microbial Proteolytic Activity

Traditional bacterial isolation methods are often costly,
have
limited throughput, and may not accurately reflect the true microbial
community composition. Consequently, identifying rare or slow-growing
taxa becomes challenging. Over the past decade, a new approach has
been proposed to replace traditional flasks or multiwell plates with
ultrahigh-throughput droplet microfluidic screening assays. In this
study, we present a novel passive droplet-based method designed for
isolating proteolytic microorganisms, which are crucial in various
biotechnology industries. Following the encapsulation of single cells
in gelatin microgel compartments and their subsequent clonal cultivation,
microcultures are passively sorted at high throughput based on the
deformability of droplets. Our novel chip design offers a 50-fold
improvement in throughput compared to a previously developed deformability-based
droplet sorter. This method expands an array of droplet-based microbial
enrichment assays and significantly reduces the time and resources
required to isolate proteolytic bacteria strains.