Simultaneous saccharification and fermentation of steam exploded duckweed: Improvement of the ethanol yield by increasing yeast titre

Abstract

HighlightsSteam explosion of duckweed enhances SSF at low (2% w/v) substrate concentrations.High substrate concentrations (20% w/v) result in much lower ethanol yields.Ethanol yields can be considerably increased with higher yeast inoculum.Or by preconditioning yeasts in steam explosion liquor containing inhibitors.The extra/preconditioned yeast metabolise fermentation inhibitors.

Structural Analysis of Alkaline Pretreated Rice Straw for Ethanol Production

“…The yeast S. cerevisiae was activated to the exponential growth phase prior to SSF and the relatively high amount of yeast cells was used, thus resulting in no lag phase over 96 h SSF ( Figure 6) and improving ethanol yield [30,32]. In addition, the yeast strain has been reported to tolerate towards fermentation inhibitors and efficiently ferments glucose to ethanol [33].…”

“…The pretreated substrate used for SSF was washed with water for several times after pretreatment, thereby lowering concentration of inhibitors, which can reduce yeast performance. In terms of substrate loading, the 10% loadings of the pretreated substrate allow mass transfer, making the system less viscous [32]. Thus, this substrate loading enables the diffusion of enzymes and hydrolysis products and may not decrease the fermentation capability of the yeast.…”

Duckweed (Lemnaceae): Its Molecular Taxonomy

“…Lemnaceae (commonly known as water lens or duckweed) is a family of monocotyledonous water plants (Landolt, 1986;Landolt and Kandeler, 1987;Sree et al, 2016) characterized by the fastest growth rates among flowering plants (Sree et al, 2015b;Ziegler et al, 2015). As a consequence, the rate of biomass production is high, which provides the basis for different practical applications of duckweeds in the areas of food and feed sustainability (Landolt and Kandeler, 1987;Appenroth et al, 2017Appenroth et al, , 2018Sonta et al, 2019) and biotechnology (Zhao et al, 2015;Chen et al, 2018;Kaur et al, 2018;Ren et al, 2018).…”

Optimization of the laccase detoxification step in hybrid hydrolysis and fermentation processes from wheat straw by K. marxianus CECT 10875

“…In our work, the initial acetic acid concentration in the slurry was 2.5 g/L demonstrating that K. marxianus CECT 10875 was more resistant to acetic acid than others K. marxianus strains. It is known that robustness of yeast strain is favored when the size of the inoculum is maximized [33,34]. In this context, the development of robust inocula becomes crucial in ethanol production processes.…”