Construction of advanced producers of first- and second-generation ethanol in Saccharomyces cerevisiae and selected species of non-conventional yeasts (Scheffersomyces stipitis, Ogataea polymorpha)

Abstract

This review summarizes progress in the construction of efficient yeast ethanol producers from glucose/sucrose and lignocellulose. Saccharomyces cerevisiae is the major industrial producer of first-generation ethanol. The different approaches to increase ethanol yield and productivity from glucose in S. cerevisiae are described. Construction of the producers of secondgeneration ethanol is described for S. cerevisiae, one of the best natural xylose fermenters, Scheffersomyces stipitis and the most thermotolerant yeast known Ogataea polymorpha. Each of these organisms has some advantages and drawbacks. S. cerevisiae is the primary industrial ethanol producer and is the most ethanol tolerant natural yeast known and, however, cannot metabolize xylose. S. stipitis can effectively ferment both glucose and xylose and, however, has low ethanol tolerance and requires oxygen for growth. O. polymorpha grows and ferments at high temperatures and, however, produces very low amounts of ethanol from xylose. Review describes how the mentioned drawbacks could be overcome.

Ethanol-Enriched Substrate Facilitates Ambrosia Beetle Fungi, but Inhibits Their Pathogens and Fungal Symbionts of Bark Beetles

“…This tolerance is close to the naturally occurring, wild-type strains of yeasts (up to 6% ethanol by certain species in the genus Saccharomyces , Candida , Fabospora , Kluyveromyces , Kloeckera ) and of specific filamentous fungi (3–7% by certain species in the genus Rhizopus and Fusarium ) used for producing ethanol and above the typical limits of alcohol tolerance in other fungal species ( Gao and Fleet, 1988 ; Singh and Kumar, 1991 ; Singh et al, 1992 ; Skory et al, 1997 ; Banat et al, 1998 ; Pina et al, 2004 ; Benjaphokee et al, 2012 ; Ferreira et al, 2014 ; Lam et al, 2014 ; Paschos et al, 2015 ; Ruchala et al, 2020 ). In biotechnology, ethanol tolerance and production of fungi can be increased by culture dependent methods (e.g., pH, temperature, medium, carbon-source), genetic modifications and artificial selection (e.g., Gao and Fleet, 1988 ; Skory et al, 1997 ; Pina et al, 2004 ; Benjaphokee et al, 2012 ; Lam et al, 2014 ; Ruchala et al, 2020 ). The extraordinary tolerance of some of our tested fungi in combination with the known ethanol production of ambrosia beetle fungi makes them quite interesting for biotechnological purposes (i.e., second-generation biofuels made from plant biomass).…”

ATPase-based implementation of enforced ATP wasting in Saccharomyces cerevisiae for improved ethanol production

“…Worldwide annual production is currently more than 100 billion L and it is expected to cross 134 billion L by 2024 [ 2 ]. Saccharomyces cerevisiae is the predominant organism used for bioethanol production and there is great interest in generating superior production strains [ 3 , 4 ] since merely a 1% increase in ethanol yield can already save the industry millions of dollars annually [ 5 ]. Some characteristics of S. cerevisiae that make it an ideal host for industrial production are efficient anaerobic ethanol production, tolerance to ethanol and other stress factors such as low pH as well as its insensitivity to bacteriophage infection.…”

Studies of Cellulose and Starch Utilization and the Regulatory Mechanisms of Related Enzymes in Fungi

“…Some of the most significant food and beverages known to humans (such as beer, wine, and bread) are made through the alcoholic fermentation process. These traditional fermentation products are produced by using yeast strains to spontaneously ferment carbon-rich substrates (e.g., bread/beer from cereals, wine from grapes) [36,[47][48][49]. Some studies have shown that despite many kinds of microbes involved in the brewing of wine and other fermentation production, S. cerevisiae has always been the dominant species [50][51][52].…”