Fermentation strategy for second generation ethanol production from sugarcane bagasse hydrolyzate by Spathaspora passalidarum and Scheffersomyces stipitis

Abstract

Alcoholic fermentation of released sugars in pretreatment and enzymatic hydrolysis of biomass is a central feature for second generation ethanol (E2G) production. Saccharomyces cerevisiae used industrially in the production of first generation ethanol (E1G) convert sucrose, fructose, and glucose into ethanol. However, these yeasts have no ability to ferment pentose (xylose). Therefore, the present work has focused on E2G production by Scheffersomyces stipitis and Spathaspora passalidarum. The fermentation strategy with high pitch, cell recycle, fed-batch mode, and temperature decrease for each batch were performed in a hydrolyzate obtained from a pretreatment at 130°C with NaOH solution (1.5% w/v) added with 0.15% (w/w) of anthraquinone (AQ) and followed by enzymatic hydrolysis. The process strategy has increased volumetric productivity from 0.35 to 0.38 g · L · h (first to third batch) for S. stipitis and from 0.38 to 0.81 g · L · h for S. passalidarum (first to fourth batch). Mass balance for the process proposed in this work showed the production of 177.33 kg ethanol/ton of sugar cane bagasse for S. passalidarum compared to 124.13 kg ethanol/ton of sugar cane bagasse for S. stipitis fermentation. The strategy proposed in this work can be considered as a promising strategy in the production of second generation ethanol. Biotechnol. Bioeng. 2017;114: 2211-2221. © 2017 Wiley Periodicals, Inc.

The yeasts of the genus Spathaspora: potential candidates for second‐generation biofuel production

“…passalidarum can ferment these sugars simultaneously, with ethanol yields of up to 0.42 g g −1 (Hou, ; Long et al ., ; Su et al ., ). Additionally, in a recent study, this yeast was able to consume all of the glucose and >90% of the xylose when cultured in sugarcane bagasse hydrolysate (Nakanishi et al ., ). In this work, the glucose content in the hydrolysate was nearly 3‐fold higher than that of xylose, and no inhibitors such acetic acid, furfural and hydroxymethylfurfural were detected.…”

A Bibliometric Study of Scientific Publications regarding Hemicellulose Valorization during the 2000–2016 Period: Identification of Alternatives and Hot Topics

“…This trend has recently changed after studies describing the isolation, description and application of new xylose-fermenting yeasts from particular habitats, such as wood-boring insects and rotting wood [185]. These new species belong to the xylose-fermenting clades Spathaspora and Scheffersomyces [186].…”

The Xylose Metabolizing Yeast Spathaspora passalidarum is a Promising Genetic Treasure for Improving Bioethanol Production

“…Such directed high flux rates to glycolytic routes and pentose phosphate pathway was the cause for high levels of bioethanol production in S. passalidarum [31]. In large scale fed-batch fermentation study, S. passalidarum was able metabolize around 90% of xylose sugar and all of glucose of sugarcane bagasse hydrolysate, even so glucose had approximately three-fold higher xylose content; and produced a high ethanol yield of 0.46 g/g with volumetric productivity of 0.81 g/L/h in contrast to P. stipitis which produced 0.32 g/g ethanol with productivity of 0.36 g/L/h [32]. In follow up study, S. passalidarum UFMG-CM-Y473 strain was able to simultaneously utilize and co-ferment about 78% of the released sugars (xylose, glucose, and cellobiose) of pretreated sugarcane bagasse hydrolysate (delignified and enzymatically hydrolyzed) to yield up to 0.32 g/g bioethanol with productivity of 0.34 g/L/h without any nutritional supplementation [33].…”