Effects of different concentrations of amino acids that are abundant in ELPs such as glycine (G), proline (P), alanine (A), and valine (V), as well as ammonia (NH3), on cell density (A), the amount of protein expressed per cell (B), and protein yield per ml of culture (C) in 50 ml uninduced cultures of E. coli expressing GFP-ELP after 24 hours (two replicates total). Data for various conditions were normalized to the control (LB + PBG). For the control, OD600, mean FI/cell, and total FI/ml are 10.66, 185.8, and 32049, respectively.