Exploring grape marc as trove for new thermotolerant and inhibitor-tolerant Saccharomyces cerevisiae strains for second-generation bioethanol production

The present study aims to valorize the Typha australis stems, through second-generation bioethanol production using enzymatic hydrolysis and fermentation. The monitoring of fermentation kinetics parameters, such as pH, density, length of fermentation, and the Brix, indicated a great variability of these parameters during the fermentation process of the must with three Saccharomyces cerevisiae strains, such as Angel brand Thermal-tolerant alcohol active dry yeast, Angel brand super alcohol active dry yeast and Angel super alcohol active dry yeast in the presence of urea (CON2H4) used as a growth factor. The distillation of musts after fermentation has yielded ethanol extraction rate (% v / v at 20 ° C) between 4.95and 44.93 after fractional distillation. The best performance in ethanolic bioconversion was recorded with Angel brand super alcohol active dry yeast. This Saccharomyces cerevisiae strains could be used as effective ferments, in perspective of intensive production of second-generation bioethanol with Typha australis stems.

Download Full-text

Cell-recycle batch process of Scheffersomyces stipitis and Saccharomyces cerevisiae co-culture for second generation bioethanol production

Biotechnology Letters ◽

10.1007/s10529-015-1919-9 ◽

2015 ◽

Vol 37 (11) ◽

pp. 2213-2218 ◽

Cited By ~ 6

Author(s):

Selim Ashoor ◽

Francesca Comitini ◽

Maurizio Ciani

Keyword(s):

Saccharomyces Cerevisiae ◽

Second Generation ◽

Batch Process ◽

Bioethanol Production ◽

Scheffersomyces Stipitis ◽

Cell Recycle ◽

Second Generation Bioethanol

Download Full-text

Flocculation Causes Inhibitor Tolerance in Saccharomyces cerevisiae for Second-Generation Bioethanol Production

Applied and Environmental Microbiology ◽

10.1128/aem.01906-14 ◽

2014 ◽

Vol 80 (22) ◽

pp. 6908-6918 ◽

Cited By ~ 39

Author(s):

Johan O. Westman ◽

Valeria Mapelli ◽

Mohammad J. Taherzadeh ◽

Carl Johan Franzén

Keyword(s):

Saccharomyces Cerevisiae ◽

Second Generation ◽

Raw Materials ◽

Defined Medium ◽

Bioethanol Production ◽

Dilute Acid ◽

Fermentation Inhibitors ◽

Inhibitor Tolerance ◽

Content Type ◽

Second Generation Bioethanol

ABSTRACTYeast has long been considered the microorganism of choice for second-generation bioethanol production due to its fermentative capacity and ethanol tolerance. However, tolerance toward inhibitors derived from lignocellulosic materials is still an issue. Flocculating yeast strains often perform relatively well in inhibitory media, but inhibitor tolerance has never been clearly linked to the actual flocculation abilityper se. In this study, variants of the flocculation geneFLO1were transformed into the genome of the nonflocculating laboratory yeast strainSaccharomyces cerevisiaeCEN.PK 113-7D. Three mutants with distinct differences in flocculation properties were isolated and characterized. The degree of flocculation and hydrophobicity of the cells were correlated to the length of the gene variant. The effect of different strength of flocculation on the fermentation performance of the strains was studied in defined medium with or without fermentation inhibitors, as well as in media based on dilute acid spruce hydrolysate. Strong flocculation aided against the readily convertible inhibitor furfural but not against less convertible inhibitors such as carboxylic acids. During fermentation of dilute acid spruce hydrolysate, the most strongly flocculating mutant with dense cell flocs showed significantly faster sugar consumption. The modified strain with the weakest flocculation showed a hexose consumption profile similar to the untransformed strain. These findings may explain why flocculation has evolved as a stress response and can find application in fermentation-based biorefinery processes on lignocellulosic raw materials.

Download Full-text

Optimization of Bioethanol Production from Enzymatic Treatment of Argan Pulp Feedstock

Molecules ◽

10.3390/molecules26092516 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2516

Author(s):

Jihane Zeghlouli ◽

Gwendoline Christophe ◽

Amine Guendouz ◽

Cherkaoui El Modafar ◽

Abdeljalil Belkamel ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Enzymatic Hydrolysis ◽

Second Generation ◽

Enzymatic Treatment ◽

Grinding Process ◽

Sugar Solution ◽

Bioethanol Production ◽

Second Generation Bioethanol ◽

Argan Oil ◽

First Time

Argan pulp is an abundant byproduct from the argan oil process. It was investigated to study the feasibility of second-generation bioethanol production using, for the first time, enzymatic hydrolysis pretreatment. Argan pulp was subjected to an industrial grinding process before enzymatic hydrolysis using Viscozyme L and Celluclast 1.5 L, followed by fermentation of the resulting sugar solution by Saccharomyces cerevisiae. The argan pulp, as a biomass rich on carbohydrates, presented high saccharification yields (up to 91% and 88%) and an optimal ethanol bioconversion of 44.82% and 47.16% using 30 FBGU/g and 30 U/g of Viscozyme L and Celluclast 1.5 L, respectively, at 10%w/v of argan biomass.

Download Full-text