Fig. 5.

Library construction and screening strategies. a Plasmid and part of the CtAAAH-F gene were amplified with phosphorothioate primers and (b) cleavage with I₂/EtOH solution leaving sticky ends. The amplicon was hybridized with (c) synthetic phosphorylated oligos and (d) transformed into an E. coli strain which contains an intracellular tryptophan fluorescent sensor. e Tryptophan consumers can be distinguished by the lack or diminished formation of fluorescence