Robust yeast with high inhibitor, temperature and osmotic tolerance remain a critical requirement for the sustainable production of lignocellulosic bioethanol. In this work, grape marc was selected as extreme environment to search for innately robust yeast because of its limited nutrients, exposure to solar radiation, temperature fluctuations and ethanol content. Forty newly isolated Saccharomyces cerevisiae strains gave high ethanol yields at 40 °C when inoculated in minimal media at high sugar concentrations. Moreover, the isolates showed distinct inhibitor-tolerance in defined broth supplemented with increasing levels of single inhibitors or a cocktail of inhibitory compounds. Both fermentative abilities and inhibitor resistance were greater than those exhibited by industrial and commercial S. cerevisiae benchmark yeast. The isolate Fm17, exhibiting the most promising phenotype, was then evaluated to ferment liquor from steam-exploded sugarcane bagasse, having high concentrations of weak acids, furans and aldehydes. The selected strain produced high alcohol levels with an ethanol yield equal to 89% of the theoretical. This work demonstrated that yeast with high multiple stress tolerance can be obtained from unconventional ecological niches, such as grape marc. The selected yeast represents a promising platform to develop robust engineered strains suitable for the one-step processing of biomass into ethanol.

Robust yeast for the production of bioethanol from steam-exploded sugarcane bagasse

FAVARO, LORENZO;CAGNIN, LORENZO;CASELLA, SERGIO;BASAGLIA, MARINA
2014

Abstract

Robust yeast with high inhibitor, temperature and osmotic tolerance remain a critical requirement for the sustainable production of lignocellulosic bioethanol. In this work, grape marc was selected as extreme environment to search for innately robust yeast because of its limited nutrients, exposure to solar radiation, temperature fluctuations and ethanol content. Forty newly isolated Saccharomyces cerevisiae strains gave high ethanol yields at 40 °C when inoculated in minimal media at high sugar concentrations. Moreover, the isolates showed distinct inhibitor-tolerance in defined broth supplemented with increasing levels of single inhibitors or a cocktail of inhibitory compounds. Both fermentative abilities and inhibitor resistance were greater than those exhibited by industrial and commercial S. cerevisiae benchmark yeast. The isolate Fm17, exhibiting the most promising phenotype, was then evaluated to ferment liquor from steam-exploded sugarcane bagasse, having high concentrations of weak acids, furans and aldehydes. The selected strain produced high alcohol levels with an ethanol yield equal to 89% of the theoretical. This work demonstrated that yeast with high multiple stress tolerance can be obtained from unconventional ecological niches, such as grape marc. The selected yeast represents a promising platform to develop robust engineered strains suitable for the one-step processing of biomass into ethanol.
Global Biotechnology Congress 2014: Abstracts and Conference Program
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11577/2920899
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact