Design and optimization of ethanol production from bagasse pith hydrolysate by a thermotolerant yeast Kluyveromyces sp. IIPE453 using response surface methodology

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Table 2 Factors with their coded levels

Serial number	Variable	Low (-1)	Center point (0)	High (+1)
1	pH	4.5	5	5.5
2	Fermentation time (h)	24	36	48
3	Substrate Concentration (g/L)	20	30	40
4	Yeast extract (g/L)	1	2.5	5
5	MgSO₄(g/L)	0.06	0.09	0.12
6	(NH₄)₂SO₄ (g/L)	1	3	5
7	Na₂HPO₄(g/L)	0.15	0.30	0.45
8	KH₂PO₄(g/L)	0.15	0.30	0.45
9	Inoculum volume (% v/v)	5	7.5	10