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

Table 1 Inhibitor composition of different lignocellulose hydrolysates as reported in the literature

Hydrolysate	Acetic Acid (g/L)	Formic Acid (g/L)	Levulinic acid (g/L)	Furfural (g/L)	HMF (g/L)	References
Agave bagasse	7.8–8.3	2.0–3.6	N.D	N.D	N.D	[30]
Alder	9.1–11.2	N.D	N.D	0.2–1.4	2.6–4.5	[34]
Aspen hardwood	8.2–10.1	0.0	0.0	2.1–3.5	1.3–6.8	[34]
Bark	0.0–6.2	N.D	N.D	0.5–1.0	0.4–4.3	[34]
Barley straw	N.D	N.D	N.D	2.9	1.0	[32]
Biowaste	2.0	N.D	N.D	0.0	N.D	[29]
Birch hardwood	2.0–11.5	4.6	0.0	0.2–4.6	0.1–5.8	[29, 34, 53]
Cardboard	0.5	N.D	N.D	0.1	N.D	[29]
Coffee husks	2.9	N.D	N.D	0.0	0.3	[54]
Corn cob	6.0	N.D	N.D	0.4	N.D	[29]
Corn stover	0.0–2.2	0.0–6.8	0.0–2.2	0.6–11.0	0.1–5.3	[35, 55]
Oil palm	5.0–9.0	N.D	N.D	1.0–1.2	N.D	[29]
Pine	0.0–3.7	0.0	0.0	0.7–6.9	1.0–8.6	[34]
Rice husks	1.8–2.1	2.5–2.7	N.D	N.D	N.D	[30]
Rice straw	2.3	N.D	N.D	0.1	0.3	[33]
Sorghum bagasse	1.0	0.16	0.2	0.0	1.6	[31]
Spruce	0.0.–4.7	0.6–3.1	0.2–3.2	0.2–1.4	0.5–8.4	[17, 21, 32, 34, 56]
Sugar cane bagasse	N.D.–4.9	N.D.–2.5	N.D.–2.7	0.1–3.1	0.1–3.0	[17, 29, 54]
Wheat straw	3.0–7.0	0.0–1.3	0.0	0.4–1.4	0.1–0.3	[29, 32, 40]
Willow	N.D	N.D	N.D	0.3–3.2	0.6–3.9	[34]

The hydrolysates listed were made with different types of biomass and different pre-treatment methods, resulting in broad variation in the levels of some inhibitors. The level of phenolic compounds was only determined in a limited number of studies and these data are not included in the table
ND not determined, EFB empty fruit bunch

ISSN: 2731-3654