麻豆淫院

Chinese researchers have developed an advanced, high-throughput single-cell sorting platform that enables direct isolation of living cells with targeted metabolic profiles from large mutant libraries.

The technology鈥攏ow commercialized as FlowRACS 3.0鈥攄ramatically shortens the traditionally labor-intensive, colony-by-colony screening process for identifying high-value microbial strains. What once took months or even years can now be accomplished in hours or days.

The research was led by Profs. Ma Bo, Xu Jian, and Feng Yingang from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) at the Chinese Academy of Sciences, and was recently in the Proceedings of the National Academy of Sciences.

The breakthrough process鈥攑ositive dielectrophoresis-induced deterministic lateral displacement-based Raman-activated cell sorting (pDEP-DLD-RACS)鈥攍everages Raman spectroscopy to enable noninvasive, label-free, and high-throughput analysis of metabolic traits in hundreds of single cells per minute. This advance allows for real-time identification and recovery of metabolically distinct cells without the need for staining or compromising cell health.

The pDEP-DLD-RACS platform integrates three critical advancements: high signal fidelity for extracting a wide range of cellular metabolic phenotypes, rapid sorting speed of up to 600 events per minute, and robust operational stability, enabling continuous operation for more than 10 hours.

By integrating wide microfluidic channels, precise dielectrophoretic control, and optimized Raman detection, the system efficiently recovers rare cells from genetically diverse populations while preserving high levels of cell viability.

To demonstrate its industrial potential, the researchers applied pDEP-DLD-RACS to a genome-wide random mutagenesis library of Aurantiochytrium sp., a microorganism critical for docosahexaenoic acid (DHA) production. In two days, the platform screened more than 250,000 cells, isolating a mutant strain that produces 58% more DHA than the wild type.

The strain also exhibited 34% higher lipid content and 21% greater DHA purity鈥攌ey metrics for the DHA industry鈥攃ompared to the baseline strain. By contrast, the team's previous lead strain required years of traditional colony-based screening to develop.

"This platform redefines microbial screening by shifting from reliance on fluorescent markers or prolonged culturing to real-time chemical phenotyping," said Prof. Feng. "It's akin to using a metabolic 'fingerprint' to instantly identify top-performing cells."

Prof. Ma added, "This work marks a milestone in live-cell phenotypic screening, demonstrating that Raman flow cytometry can transition from basic research to a practical engine for industrial strain optimization in biotechnology."

Transcriptome analysis of the high-performing mutant revealed comprehensive metabolic reprogramming, including enhanced carbon flux into lipid synthesis and a shifted redox balance favoring polyunsaturated fatty acid production. These findings confirm pDEP-DLD-RACS's screening accuracy and provide a roadmap for future metabolic engineering.

"Beyond a sorting tool, this is a 'living gem' discovery engine," said Prof. Xu. "Its ability to preserve cell viability while rapidly and cost-effectively selecting for complex metabolic traits positions it as an ideal tool for ecological monitoring and functional cell mining in diverse environments鈥攆rom industrial bioreactors to oceans and health care settings."

By integrating microfluidics, dielectrophoresis, and Raman spectroscopy, the study addresses long-standing bottlenecks in biotechnological screening, paving the way for faster development of microbial cell factories and innovative applications in synthetic biology, pharmaceuticals, and environmental science.