Ethanol fermentation using macroporous monolithic hydrogels as yeast cell scaffolds

2021 ◽  
pp. 105075
Author(s):  
Hideaki Tokuyama ◽  
Ryo Aoyagi ◽  
Kazuto Fujita ◽  
Yuki Maekawa ◽  
Shohei Riya
Keyword(s):  
Yeast Cell ◽  
Ethanol Fermentation ◽  
Cell Scaffolds

scholarly journals Intensive Multiple Sequential Batch Simultaneous Saccharification and Cultivation of Kluyveromyces marxianus SS106 Thermotolerant Yeast Strain for Single-Step Ethanol Fermentation from Raw Cassava Starch

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 898 ◽  
Author(s):  
Kwanruthai Malairuang ◽  
Morakot Krajang ◽  
Rapeepong Rotsattarat ◽  
Saethawat Chamsart
Keyword(s):  
Yeast Cell ◽  
Cell Density ◽  
Ethanol Fermentation ◽  
High Cell Density ◽  
Batch Process ◽  
Cassava Starch ◽  
Single Step ◽  
Thermotolerant Yeast ◽  
High Cell ◽  
Simultaneous Saccharification

We developed the intensive multiple sequential batch simultaneous saccharification and cultivation of the selected thermotolerant yeast strain for single-step ethanol production. The selection and high-cell-density inoculum production of thermotolerant yeast able to produce ethanol under the optimal conditions for single-step ethanol fermentation has become a necessity. In this study, the newly isolated Kluyveromyces marxianus SS106 could tolerate high temperatures (35–45 °C) and grow under a wide range of pH values (3.0–5.5), which are the optimum conditions of raw cassava starch hydrolyzing enzyme used in single-step ethanol fermentation. The high-cell-density concentration of K. marxianus SS106 was produced by a single batch and an intensive multiple sequential batch process in a 5-L stirred tank bioreactor using the simultaneous saccharification and cultivation (SSC) method. The single SSC process yielded the yeast cell biomass at a concentration of 39.30 g/L with a productivity of 3.28 g/L/h and a specific growth rate of 0.49 h−1. However, the yeast cell density concentration was higher in the intensive multiple sequential batch SSC than in the single batch process. This process yielded yeast cell biomass at concentrations of 36.09–45.82 g/L with productivities of 3.01–3.82 g/L/h and specific growth rates of 0.29–0.44 h−1 in the first six batch cycle. The results suggested that the intensive multiple sequential batch simultaneous saccharification and cultivation of K. marxianus SS106 would be a promising process for high-cell-density yeast production for use as the inoculum in single-step ethanol fermentation. Furthermore, we also experimented with single-step ethanol production from raw cassava starch by K. marxianus SS106 in a 5-L stirred tank fermenter. This produced ethanol at a concentration of 61.72 g/L with a productivity of 0.86 g/L/h.

scholarly journals Physiological mechanism of improved tolerance of Saccharomyces cerevisiae to lignin-derived phenolic acids in lignocellulosic ethanol fermentation by short-term adaptation

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Hanqi Gu ◽  
Yuyong Zhu ◽  
Yanfang Peng ◽  
Xiujun Liang ◽  
Xiaoguang Liu ◽  
...  
Keyword(s):  
Yeast Cell ◽  
Lignocellulosic Biomass ◽  
Phenolic Acids ◽  
Ethanol Fermentation ◽  
Parental Strain ◽  
Cytoplasmic Membrane ◽  
Membrane Integrity ◽  
Adaptation Strategies ◽  
Short Term ◽  
Short Term Adaptation

Abstract Background Phenolic acids are lignin-derived fermentation inhibitors formed during many pretreatment processes of lignocellulosic biomass. In this study, vanillic, p-hydroxybenzoic, and syringic acids were selected as the model compounds of phenolic acids, and the effect of short-term adaptation strategies on the tolerance of S. cerevisiae to phenolic acids was investigated. The mechanism of phenolic acids tolerance in the adapted yeast strains was studied at the morphological and physiological levels. Results The multiple phenolic acids exerted the synergistic inhibitory effect on the yeast cell growth. In particular, a significant interaction between vanillic and hydroxybenzoic acids was found. The optimal short-term adaptation strategies could efficiently improve the growth and fermentation performance of the yeast strain not only in the synthetic media with phenolic acids, but also in the simultaneous saccharification and ethanol fermentation of corncob residue. Morphological analysis showed that phenolic acids caused the parental strain to generate many cytoplasmic membrane invaginations with crack at the top of these sites and some mitochondria gathered around. The adapted strain presented the thicker cell wall and membrane and smaller cell size than those of the parental strain. In particular, the cytoplasmic membrane generated many little protrusions with regular shape. The cytoplasmic membrane integrity was analyzed by testing the relative electrical conductivity, leakage of intracellular substance, and permeation of fluorescent probe. The results indicated that the short-term adaptation improved the membrane integrity of yeast cell. Conclusion The inhibition mechanism of phenolic acid might be attributed to the combined effect of the cytoplasmic membrane damage and the intracellular acidification. The short-term adaptation strategy with varied stressors levels and adaptive processes accelerated the stress response of yeast cell structure to tolerate phenolic acids. This strategy will contribute to the development of robust microbials for biofuel production from lignocellulosic biomass.

scholarly journals Rapid ethanol fermentation in immobilized yeast cell reactor

1980 ◽  
Vol 22 (7) ◽  
pp. 1489-1496 ◽  
Author(s):  
T. K. Ghose ◽  
K. K. Bandyopadhyay
Keyword(s):  
Yeast Cell ◽  
Ethanol Fermentation ◽  
Immobilized Yeast ◽  
Cell Reactor

Drinking Animals: Sobriety, Intoxication and Interspecies Assemblages

2018 ◽  
Author(s):  
Gary Genosko
Keyword(s):  
American Literature ◽  
Ethanol Fermentation ◽  
Pure Form ◽  
Biological Factors ◽  
Multiple Species ◽  
Wine Bottle

While Deleuze explored the temporalities of alcoholism in American literature in The Logic of Sense, and Jean Clet Martin, among others, has extended this inquiry by further extracting the alcoholic’s lines of flight from the same literature, this chapter breaks the mould by understanding alcohol, distilled and in its pure form of ethanol, as well as its imbibition, as a question of a component that passes through anthropocentric, and across multiple non-anthropocentric assemblages. The exploitation of ethanol fermentation, for example, exists across species. Indeed, as we entertain more overtly human cultural examples, such as ‘wine’ for cats, a recent Japanese pet trend, the metabolic communion of interspecies companionship requires that the material expressivity of the substance is overcoded because the ‘wine’ is not only non-alcoholic but liquid catnip in a ‘wine’ bottle. Indeed, theorization of the pursuit of shared pleasures – using Guattari’s ethological terms, we might say deterritorializing from deterministic biological factors yet also modifying these in some measure as well (Machinic Unconscious) – and engaging multiple species is this chapter’s goal, achievable by plotting the passages of alcohol and its related components across assemblages and their material and socio-cultural expressive trajectories beyond strictly anthropocentric and Western prerogatives.

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