Valorization of Pinus taeda hemicellulosic hydrolysate for the production of value-added compounds in an ethanol biorefinery

Production of cellulosic ethanol from lignocellulosic biomass leads to the generation a hemicellulosic hydrolysate during feedstock pretreatment. This is rich in sugars, but also contains inhibitory compounds (mainly acetic acid and phenolic compounds) concentrations that may be toxic microbial growth. Currently, this side-stream production process processed as waste, due lack feasible alternatives for tackling complexity wood hydrolysate. Thus, work evaluated ability six microorganisms metabolize raw detoxified produced Pinus taeda lactic acid, ethanol, xylitol, single-cell protein, lipids carotenoids, with aim selecting potential alternative valorization side stream generated contributing implementation sustainable advanced biorefinery. The tested included bacterium, Bacillus coagulans; probiotic Lactobacillus salivarius; two oleaginous yeasts, Rhodosporidium toruloides Saitoella coloradoensis; thermotolerant yeast, Kluyveromyces marxianus; methylotrophic Hansenula polymorpha. L. salivarius, K. marxianus, H. polymorpha showed promising partially (composed (g/L): mannose, 29.27; glucose, 17.25; galactose, 6.18; xylose, 4.94; arabinose, 1.23; 7.99; formic 4.86; levulinic 4.04; 5-hydroxymethylfurfural, 0.74; total compounds, 0.40). On other hand, yeasts B. coagulans presented high sensitivity compounds. salivarius yield (1.1 g/g), which was limited by product inhibition. marxianus xylitol at 0.37 g/g xylose 0.19 hexoses. Finally, converted hexoses into protein 0.27 g/g. proved an