Microbial growth phenotype screening is a rate-limiting step facing the fields of industrial breeding, enzyme directed evolution and synthetic biology. Accurate single-cell precision growth phenotype measurement is the key to break the above bottleneck. Recently, the Single Cell Center of the CAS Qingdao Institute of Bioenergy and Processes has developed a low-cost, non-labeled microdroplet microfluidic platform. The platform can complete microbial growth phenotype screening at the single-cell level through single-cell microdroplet culture, droplet autofluorescence detection, and automatic sorting of target microdroplets, and demonstrate the accuracy and reliability of the method in E. coli, providing a powerful means for rapid screening of industrial strains. The research results were published in Sensors and Actuators B: Chemical.
The low-cost, non-labeled droplet microfluidic screening platform is based on the autofluorescence of microorganisms in droplets. The platform can be used for high-throughput screening of microbial growth phenotypes. The specific process is as follows: microbial single cells are wrapped in microdroplets by droplet microfluidics and dispersed for culture; the cultured droplets are injected into the microfluidic chip, and the microdroplet autofluorescence under 365 nm laser irradiation is collected in the detection area; the optical signal is transmitted to the PMT via optical fiber, and the automatic sorting of target droplets is realized by using programming software and high-frequency voltage control.
The previous study developed a series of Raman flow-based single-cell sorting techniques, FlowRACS, which can identify and sort out strains with high single-cell metabolite content (“high yield”) in a high-throughput and efficient manner under unlabeled conditions; by coupling the single-cell level growth phenotype rapid screening technique developed in this work, we can further By coupling the single-cell level growth phenotype rapid screening technology developed in this work, the “fast-growing” strains can be further screened to achieve the goal of industrial microbial selection and breeding. The researchers will further develop key technologies and equipment for single-cell level strain selection and breeding platforms to support the development of industrial biotechnology and synthetic biology industries.