Culture condition

Glutamine synthetase (GS) U mg∙prot−1

O-acetylserine(thiol)lyase (OASTL) U mg∙prot−1

Sufficient

2.1 ± 0.4

3.1 ± 0.28

N-starved

4.3 ± 0.5

0.3 ± 0.04

S-starved

2.4 ± 0.5

15.8 ± 1.62