Table 1.

2² Complete factorial design experiment for yeastolate and FBS supplements, including three replicates of the central point plus a set of tests in star configuration

Medium formulation	Independent variables		Dependent variables
	Yeastolate ultrafiltrate (g L−1)	FBS (%)	Maximum cell concentration (cells mL−1)	Viability (%)	μmax (h−1)	Maximum cell productivity (cells mL−1 h−1)
1A	4	1	25 × 105	97	0.0106	0.17 × 105
2A	8	1	90 × 105	99	0.0155	0.18 × 105
3A	4	3	37 × 105	99	0.0114	0.24 × 105
4A	8	3	100 × 105	99	0.0169	0.23 × 105
5A	3.2	2	18 × 105	99	0.0062	0.13 × 105
6A	8.8	2	79 × 105	n.d	n.d.	n.d.
7A	6	0.59	110 × 105	99	0.0220	0.18 × 105
8A	6	3.4	110 × 105	99	0.0144	0.16 × 105
9A	6	2	91 × 105	99	0.0244	0.42 × 105
10A	6	2	80 × 105	99	0.0238	0.38 × 105
11A	6	2	95 × 105	99	0.0153	0.35 × 105
TC100 + 10%FBS	n.a.	10	35 × 105	99	0.0134	0.18 × 105
Sf900 II	n.a.	n.a.	91 × 105	99	0.0201	0.58 × 105

Formulations 5A–8A correspond to the star points, and 9A to 11A, to the central points; n.a.: Not added; n.d.: Not determined