Identification of the major fermentation inhibitors of recombinant 2G yeasts in diverse lignocellulose hydrolysates

Table 3 Overview of ethanol yield, ethanol productivity, percentage of the theoretical maximum yield and sugar conversion by GSE16-T18 and MD4 in bagasse hydrolysate BH 31B spiked with different inhibitors

	Ethanol yield (g/g) by GSE16-T18	Ethanol yield (g/g) by MD4	Ethanol productivity (g/L/h) by GSE16-T18	Ethanol productivity (g/L/h) by MD4	% of theoretical maximum yield by GSE16-T18	% of theoretical maximum yield by MD4	Glucose conversion (%) by GSE16-T18	Xylose conversion (%) by GSE16-T18	Glucose conversion (%) by MD4	Xylose conversion (%) by MD4
No inhibitor	0.30	0.34	0.41	0.47	58	66	99	84	99	99
2% EtOH	0.19	0.19	0.26	0.26	37	37	99	59	98	64
3 g/L Levulinic Acid	0.30	0.33	0.42	0.46	59	65	99	80	99	98
6 g/L Levulinic Acid	0.31	0.32	0.43	0.45	60	63	99	85	99	95
3 g/L Formic Acid	0.26	0.33	0.37	0.46	52	66	99	63	99	99
6 g/L Formic Acid	0.25	0.30	0.35	0.41	50	58	99	50	99	72
3 g/L Furfural	0.23	0.18	0.32	0.25	45	35	98	32	54	17
6 g/L Furfural	0.17	0.11	0.24	0.16	34	22	73	4	7	9
3 g/L 5′-HMF	0.30	0.34	0.42	0.47	59	67	99	81	99	96
6 g/L 5′-HMF	0.29	0.34	0.40	0.48	56	67	99	72	99	96
0.03 g/L Vanillin	0.30	0.35	0.42	0.48	60	68	99	89	99	99
0.10 g/L Vanillin	0.28	0.36	0.40	0.50	56	71	99	89	99	99
0.30 g/L Vanillin	0.29	0.36	0.40	0.50	57	70	99	93	99	98
0.001 g/L 4-Hydroxy benzoic acid	0.32	0.35	0.45	0.48	63	68	99	95	99	99
0.003 g/L 4-Hydroxy benzoic acid	0.32	0.34	0.44	0.47	62	67	99	93	99	99
0.010 g/L 4-Hydroxy benzoic acid	0.33	0.32	0.46	0.44	65	62	99	93	99	99
0.1% Acetic Acid	0.30	0.31	0.42	0.44	59	62	99	80	99	95
0.3% Acetic Acid	0.30	0.31	0.42	0.43	59	60	99	88	99	93
0.003 g/L 4-Hydroxy benzaldehyde	0.32	0.32	0.45	0.45	63	64	99	90	99	99
0.010 g/L 4-Hydroxy benzaldehyde	0.33	0.34	0.45	0.47	64	67	99	94	99	99
0.030 g/L 4-Hydroxy benzaldehyde	0.32	0.34	0.45	0.47	63	67	99	95	99	99

In the fermentation where 2% ethanol was added as inhibitor, this addition was subtracted from the final ethanol yield reached after 72 h

ISSN: 2731-3654