Saccharomyces cerevisiae strains for second-generation ethanol production: from academic exploration to industrial implementation

Abstract

The recent start-up of several full-scale ‘second generation’ ethanol plants marks a major milestone in the development of Saccharomyces cerevisiae strains for fermentation of lignocellulosic hydrolysates of agricultural residues and energy crops. After a discussion of the challenges that these novel industrial contexts impose on yeast strains, this minireview describes key metabolic engineering strategies that have been developed to address these challenges. Additionally, it outlines how proof-of-concept studies, often developed in academic settings, can be used for the development of robust strain platforms that meet the requirements for industrial application. Fermentation performance of current engineered industrial S. cerevisiae strains is no longer a bottleneck in efforts to achieve the projected outputs of the first large-scale second-generation ethanol plants. Academic and industrial yeast research will continue to strengthen the economic value position of second-generation ethanol production by further improving fermentation kinetics, product yield and cellular robustness under process conditions.

Unraveling the genetic basis of fast l‐arabinose consumption on top of recombinant xylose‐fermenting Saccharomyces cerevisiae

“…Previous studies proved that combining the introduction of the bacterial L-arabinose metabolic pathway and evolutionary engineering gives rise to superior S. cerevisiae strains (Jansen et al, 2017; Supporting Information Table S5). Previous studies proved that combining the introduction of the bacterial L-arabinose metabolic pathway and evolutionary engineering gives rise to superior S. cerevisiae strains (Jansen et al, 2017; Supporting Information Table S5).…”

d‐Xylose consumption by nonrecombinant Saccharomyces cerevisiae: A review

“…Industrial strains have high ethanol productivity both aerobically and anaerobically, high tolerance to elevated concentration of ethanol and low pH, and are resistant to many of the harmful compounds present on typical biomass hydrolysates (Albergaria & Arneborg, ; Della‐Bianca, Basso, Stambuk, Basso, & Gombert, ; Hagman & Piškur, ; Nandy & Srivastava, ; Piskur, Rozpedowska, Polakova, Merico, & Compagno, ; Snoek, Verstrepen, & Voordeckers, ). This yeast has been generally recognized as unable to metabolize xylose naturally; therefore, a lot of research has been directed to the use heterologous genes through recombinant technology to enable it to ferment this carbon source (Hahn‐Hägerdal, Karhumaa, Fonseca, Spencer‐Martins, & Gorwa‐Grauslund, ; Jansen et al, ; Kwak & Jin, ; Turner et al, ; Yaguchi, Spagnuolo, & Blenner, ). Nevertheless, the legislations, definitions, labelling, or even commercial use of genetically modified organisms (GMOs) differ significantly between countries (Aldemita, Reaño, Solis, & Hautea, ; Ishii & Araki, ; Lusser & Davies, ; Ramessar, Capell, Twyman, Quemada, & Christou, ), restricting in many cases the use of recombinant yeasts for second‐generation fuel ethanol production.…”

“…research has been directed to the use heterologous genes through recombinant technology to enable it to ferment this carbon source (Hahn-Hägerdal, Karhumaa, Fonseca, Spencer-Martins, & Gorwa-Grauslund, 2007;Jansen et al, 2017;Kwak & Jin, 2017;Turner et al, 2018;Yaguchi, Spagnuolo, & Blenner, 2018). Nevertheless, the legislations, definitions, labelling, or even commercial use of genetically modified organisms (GMOs) differ significantly between countries (Aldemita, Reaño, Solis, & Hautea, 2015;Ishii & Araki, 2017;Lusser & Davies, 2013;Ramessar, Capell, Twyman, Quemada, & Christou, 2008), restricting in many cases the use of recombinant yeasts for second-generation fuel ethanol production.…”

“…need to be characterized (through gene deletion and/or over-expression). Readers interested in the development of recombinant S. cerevisiae for xylose fermentation, including other yeasts, should refer to recently published reviews (Jansen et al, 2017;Kwak & Jin, 2017;Moysés, Reis, de Almeida, de Moraes, & Torres, 2016;Turner et al, 2018;Yaguchi et al, 2018).…”

The renaissance of yeasts as microbial factories in the modern age of biomanufacturing

“…Genetically engineered yeasts have been used for several decades as cell factories to manufacture diverse products including amino acids (Liu, Yu, Campbell, Nielsen, & Chen, 2018), lipids (Xue et al, 2013), heterologous enzymes (Ahmad, Hirz, Pichler, & Schwab, 2014;Graf, Dragosits, Gasser, & Mattanovich, 2009), nutraceuticals and food ingredients such as resveratrol and lycopene (Ye, Sharpe, & Zhu, 2012;Vos, de la Torre Cortes, van Gulik, Pronk, & Daran-Lapujade, 2015), and proteins for the biopharmaceutical industry (reviewed in Nielsen, 2013). Wild-type and genetically engineered yeast strains are widely used to produce ethanol as a biofuel from corn, cassava, and sugar cane (Petrovic, 2015) and or from cellulosic feedstocks (Jansen et al, 2017). The ability to heterologously generate high value products in engineered yeast factories has several advantages to the traditional methods of plant extraction and chemical synthesis.…”