Evolved strains of Scheffersomyces stipitis achieving high ethanol productivity on acid- and base-pretreated biomass hydrolyzate at high solids loading

Table 5 Comparative average resistances of superior isolates to 6, 10, and 15 g/L acetic acid in ODM with 50 g/L sugar ^a,b

Adaptation stress	Isolate		Average μ _o (h ⁻¹ ) ^c				Average ratio μ _i /μ _o ^c
			Glucose		Xylose		Glucose		Xylose
AFEX CSH	33	Colony 5	0.23	AB	0.23	A	0.86	AB	0.90	B
AFEX CSH > E	27	2A.1.53R-E20-C1	0.28	A	0.26	A	0.72	AB	0.80	B
AFEX CSH > E	28	2A.1.53R-E30-C3	0.26	AB	0.24	A	0.75	AB	0.68	B
AFEX CSH > E (UV)	30	2A.1.30R2-E40-C5	0.24	AB	0.21	A	0.93	AB	1.10	A
AFEX CSH > E > PSGHL	13	2A.1.53R S100E40-1	0.26	AB	0.25	A	0.84	AB	0.79	B
AFEX CSH > E > PSGHL	16	2A.1.53R-1	0.25	AB	0.24	A	0.88	AB	0.75	B
AFEX CSH > PSGHL	11	Colony 5-GP6	0.22	B	0.25	A	1.02	A	0.84	B
PSGHL	3	Y-7124 S90E40-1	0.25	AB	0.22	A	0.66	B	0.83	B
PSGHL	15	Y-7124-10	0.25	AB	0.24	A	0.97	A	0.85	B
PSGHL	14	Y-7124-6	0.23	AB	0.23	A	0.84	AB	0.81	B
Wild	1	Y-7124	0.24	AB	0.25	A	0.96	AB	0.87	B
Significance			P = 0.039		P = 0.223		P < 0.01		P < 0.001
Acetic acid (g/L)	Average ratio μ _i /μ _o ^d
Acetic acid (g/L)	Glucose		Xylose
6	0.98	A	0.98	A
10	0.80	B	0.89	B
15	0.79	B	0.64	C
Significance	P < 0.001		P < 0.001

^aAbbreviations are the following: μ_o = initial specific growth rate in the absence of acetic acid; μ_i = the specific growth rate in the presence of the inhibitory acetic acid.
^bWithin columns, values with no letters in common are significantly different at P < 0.05 (Student-Newman-Keuls pairwise comparison method).
^cAverage across acetic acid concentrations for a particular isolate.
^dAverage across isolates for a particular acetic acid concentration.

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