From: Optimization of glutathione production in Saccharomyces cerevisiae HBSD-W08 using Plackett–Burman and central composite rotatable designs
Factor
Level
−1
0
+ 1
KH2PO4
0.25
0.5
0.75
Glutamate
0.1%
0.15%
0.2%
Peptone
3%
4%
5%