Influence of antibiotics that inhibit macromolecular synthesis at the non-division TI feedrate of 0.18 mmol/g/h. Antibiotics were added one minute after the second pulse (yellow region). Four different ions are shown corresponding to glutamate, phenylalanine, guanine, and thymine. Chloramphenicol (blue) inhibits protein biosynthesis, rifamycin (orange) inhibits RNA polymerase, and azidothymidine (AZT; red) inhibits DNA synthesis 