On-chip analysis, indexing and screening for chemical producing bacteria in a microfluidic static droplet array.
Economic production of chemicals from microbes necessitates development of high-producing strains and an efficient screening technology is crucial to maximize the effect of the most popular strain improvement method, the combinatorial approach. However, high-throughput screening has been limited for assessment of diverse intracellular metabolites at the single-cell level. Herein, we established a screening platform that couples a microfluidic static droplet array (SDA) and an artificial riboswitch to analyse intracellular metabolite concentration from single microbial cells. Using this system, we entrapped single Escherichia coli cells in SDA to measure intracellular l-tryptophan concentrations. It was validated that intracellular l-tryptophan concentration can be evaluated by the fluorescence from the riboswitch. Moreover, high-producing strains were successfully screened from a mutagenized library, exhibiting up to 145% productivity compared to its parental strain. This platform will be widely applicable to strain improvement for diverse metabolites by developing new artificial riboswitches.
Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 790-784, Korea. gyjung@postech.ac.kr.
Sungho
S
Jang
Byungjin
B
Lee
Heon-Ho
HH
Jeong
Si Hyung
SH
Jin
Sungyeon
S
Jang
Seong Gyeong
SG
Kim
Gyoo Yeol
GY
Jung
Chang-Soo
CS
Lee
D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005453:Fluorescence; D057166:High-Throughput Screening Assays / Q000295:instrumentation* / Q000379:methods*; D056656:Lab-On-A-Chip Devices; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D009154:Mutation; D015203:Reproducibility of Results; D058928:Riboswitch; D014364:Tryptophan / Q000378:metabolism
D058928:Riboswitch; D014364:Tryptophan