Unraveling continuous 2G ethanol production from xylose using hemicellulose hydrolysate and immobilized superior recombinant yeast in fixed-bed bioreactor

Autor(es)

Perez, Caroline L. ^[1] ; Milessi, Thais S. ^{[2, 3]} ; Sandri, Juliana P. ^[1] ; Foulquie-Moreno, Maria R. ^{[4, 5]} ; Giordano, Roberto C. ^{[6, 1]} ; Thevelein, Johan M. ^{[4, 5]} ; Camargo Giordano, Raquel de Lima ^{[6, 1]} ; Zangirolami, Teresa C. ^{[6, 1]}

Afiliação do(s) autor(es)

^[1] Fed Univ Sao Carlos PPGEQ UFSCar, Grad Program Chem Engn, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Itajuba, Inst Nat Resources, Av Benedito Pereira Santos 1303, BR-37500903 Itajuba, MG - Brazil

^[3] Univ Fed Itajuba, Grad Program Energy Engn, Av Benedito Pereira Santos 1303, BR-37500903 Itajuba, MG - Brazil

^[4] Katholieke Univ Leuven, Lab Mol Cell Biol, Inst Bot & Microbiol, Kasteelpk Arenberg 31, B-3001 Leuven, Flanders - Belgium

^[5] VIB, Ctr Microbiol, Kasteelpk Arenberg 31, B-3001 Leuven, Flanders - Belgium

^[6] Univ Fed Sao Carlos, Dept Chem Engn, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Biochemical Engineering Journal; v. 169, MAY 2021.
• Citações Web of Science: 1

Resumo

Development of a robust and competitive process for second generation (2G) ethanol production requires efficient fermentation of both glucose and xylose fractions generated after biomass pretreatment and saccharification, using industrial media containing high sugars concentration and inhibitors, under prolonged exposure to high ethanol titers. Thus, it is important to study the influence of these industrial operation conditions on yeast fermentation performance, which has been little addressed in the literature. In this work we evaluated the steady-state stability of continuous 2G ethanol production from xylose in a fixed bed reactor. The bioreactor was packed with recombinant, xylose-utilizing Saccharomyces cerevisiae cells entrapped in calcium alginate and it was operated with different inlet xylose concentrations and dilution rates. Medium supplementation with nutrients and scheduled washing steps were effective in maintaining high xylose conversion levels during continuous fermentation for more than 15 days with an ethanol productivity of 5.0 g/L.h. Effects of prolonged exposure to ethanol and inhibitors present in undetoxified hydrolysate were further investigated in repeated batches. Overall, the results show that improved ethanol tolerance in recombinant yeasts and innovative solutions to increase sugar concentration in the hydrolysates are the main challenges to achieve a feasible industrial process for 2 G ethanol production. (AU)

• Processo FAPESP: 16/10636-8 - Da fábrica celular à biorrefinaria integrada Biodiesel-Bioetanol: uma abordagem sistêmica aplicada a problemas complexos em micro e macroescalas
• Beneficiário: Roberto de Campos Giordano
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático