Droplet-based microfluidic platform for high-throughput screening of Streptomyces

• Published in: Communications biology 2021-05, Vol.4 (1), p.647-647, Article 647
• Main Authors: Tu, Ran, Zhang, Yue, Hua, Erbing, Bai, Likuan, Huang, Huamei, Yun, Kaiyue, Wang, Meng
• Format: Article
• Language: English
• Subjects: 13/62; 14/35; 14/63; 631/1647/2163; 631/61/318; Biology; Biomedical and Life Sciences; Cellulase; Flow cytometry; High-throughput screening; Life Sciences; Microfluidics; Protoplasts; Spores; Stationary phase; Streptomyces
• ISSN: 2399-3642; 2399-3642
• DOI: 10.1038/s42003-021-02186-y

Streptomyces are one of the most important industrial microorganisms for the production of proteins and small-molecule drugs. Previously reported flow cytometry-based screening methods can only screen spores or protoplasts released from mycelium, which do not represent the filamentous stationary phase Streptomyces used in industrial cultivation. Here we show a droplet-based microfluidic platform to facilitate more relevant, reliable and rapid screening of Streptomyces mycelium, and achieved an enrichment ratio of up to 334.2. Using this platform, we rapidly characterized a series of native and heterologous constitutive promoters in Streptomyces lividans 66 in droplets, and efficiently screened out a set of engineered promoter variants with desired strengths from two synthetic promoter libraries. We also successfully screened out several hyperproducers of cellulases from a random S. lividans 66 mutant library, which had 69.2–111.4% greater cellulase production than the wild type. Our method provides a fast, simple, and powerful solution for the industrial engineering and screening of Streptomyces in more industry-relevant conditions. Streptomyces are an important filamentous bacterium genus in industry, but most of the high-throughput techniques so far can only separate spores or protoplasts. Tu et al. develop an encapsulating method that allows screening of Streptomyces in the filamentous, stationary phase.