CIEMAT

URI permanente para esta comunidad

https://emimasd.consorciomadrono.es/handle/11034/35

Filtrar

Organizando CIEMAT por Autor "Ibarra, David"

Mostrando1 - 2 de 2
  • Artículo
    Acceso Abierto
    Comparing cell viability and ethanol fermentation of the thermotolerant yeast Kluyveromyces marxianus and Saccharomyces cerevisiae on steam-exploded biomass treated with laccase
    (2013-12-12) Moreno, David; Ibarra, David; Ballesteros, Mercedes; Ballesteros, Ignacio; González, Alberto
    In this study, the thermotolerant yeast Kluyveromyces marxianus CECT 10875 was compared to Saccharomyces cerevisae Ethanol Red for lignocellulosic ethanol production. For it, whole slurry from steam-exploded wheat straw was used as raw material, and two process configurations, simultaneous saccharification and fermentation (SSF) and presaccharification and simultaneous saccharification and fermentation (PSSF), were evaluated. Compared to S. cerevisiae, which was able to produce ethanol in both process configurations, K. marxianus was practically inhibited, and neither growth nor ethanol production occurred during the processes. However, the prior laccase treatment of the whole slurry, which removed specifically the lignin phenols content from the overall inhibitory compounds present in slurry, triggered the fermentation by k. marxianus, attaining ethanol concentrations and yields comparable to those obtained by S. cerevisiae.
  • Artículo
    Acceso Abierto
    Improving the fermentation performance of Saccharomyces cerevisiae by laccase during ethanol production from steamexploded wheat straw at high substrate loadings
    (2013-12-12) Alvira, Pablo; Moreno, David; Ibarra, David; Saez, Felicia; Ballesteros, Mercedes
    Operating the saccharification and fermentation processes at high substrate loadings is a key factor for making ethanol production from lignocellulosic biomass economically profitable. However, increasing the substrate loading presents some disadvantages, among them larger generation of inhibitors, which negatively affect fermentation performance. In this study, laccase enzymatic treatment was evaluated as a method to reduce these inhibitory effects. The laccase efficiency was analyzed in a presaccharification and simultaneous saccharification and fermentation process (PSSF) at different high substrate loadings. Water insoluble fraction (WIS) from steam-exploded wheat straw was used as substrate and Saccharomyces cerevisiae as fermenting organism. Laccase supplementation reduced strongly the phenolics content in the media, without affecting weak acids and furan derivates. It resulted in an improved yeast performance during simultaneous saccharification and fermentation process, increasing significantly ethanol productivity.