E. coli barcoded library screen for auxotrophs benefitting from conditioned media

An E. coli barcoded library was used for a genetic screen of single-gene knockout strains that can benefit from metabolites secreted by other cells. Minimal media conditioned by different density cultures of a wild type E. Coli strain was prepared for this purpose. The parent strain of the library is BW38028. This library consists of 3,680 individual knockout strains with their own unique 20 bp sequence serving as an identification barcode. The screen using the pooled library was performed with biological triplicates for the control minimal media condition and biological duplicates for the conditioned media conditions. The barcoded regions were amplified in each screen sample, and this barcode amplicon product was used for Illumina NGS.