Portal de Periódicos da CAPES

Ethanol production by Escherichia coli from detoxified lignocellulosic teak wood hydrolysates with high concentration of phenolic compounds

2021; Springer Science+Business Media; Volume: 49; Issue: 2 Linguagem: Inglês

10.1093/jimb/kuab077

1476-5535

Estefanía Sierra-Ibarra, Jorge Alcaraz‐Cienfuegos, Alejandra Vargas‐Tah, Alberto Rosas‐Aburto, Ángeles Valdivia-López, Martín G. Hernández-Luna, Eduardo Vivaldo‐Lima, Alfredo Martı́nez,

Catalysis for Biomass Conversion

Teak wood residues were subjected to thermochemical pretreatment, enzymatic saccharification, and detoxification to obtain syrups with a high concentration of fermentable sugars for ethanol production with the ethanologenic Escherichia coli strain MS04. Teak is a hardwood, and thus a robust deconstructive pretreatment was applied followed by enzymatic saccharification. The resulting syrup contained 60 g l-1 glucose, 18 g l-1 xylose, 6 g l-1 acetate, less than 0.1 g l-1 of total furans, and 12 g l-1 of soluble phenolic compounds (SPCs). This concentration of SPC is toxic to E. coli, and thus two detoxification strategies were assayed: (1) treatment with Coriolopsis gallica laccase followed by addition of activated carbon and (2) overliming with Ca(OH)2. These reduced the phenolic compounds by 40% and 76%, respectively. The detoxified syrups were centrifuged and fermented with E. coli MS04. Cultivation with the overlimed hydrolysate showed a 60% higher volumetric productivity (0.45 gETOH l-1 hr-1). The bioethanol/sugar yield was over 90% in both strategies.