Enzymatic Hydrolysis of Sodium Dodecyl Sulphate (SDS)—Pretreated Newspaper for Cellulosic Ethanol Production by Saccharomyces cerevisiae and Pichia stipitis

NaOH/urea (NU) pretreatment at lower than 0 °C has been frequently applied for improving bio-conversion of lignocellulose, but the wastewater generated from the pretreatment process is hard to dispose. KOH/urea (KU) pretreatment for enhancing bioconversion of lignocellulose has recently attracted researchers’ attention due to the recycling of wastewater for facilitating crops’ growth. This study compared the effects of NU and KU pretreatments at cold conditions on the enzymatic hydrolysis and bioethanol yield from wheat straw (WS). By using response surface methodology an optimal pretreatment with an equal ratio of alkali/urea (4% w/v) at −20 °C for 3 h was established. The enzymatic hydrolysis of KU-treated WS was 81.17%, which was similar to that of NU-treated WS (83.72%) under the same condition. It means that KU pretreatment has equal ability to NU pretreatment to improve enzymatic saccharification of lignocellulose. KU pretreatment has the promising potential to replace NU pretreatment for facilitating bioconversion of lignocellulose in cold conditions due to the clean way to recycle its wastewater as fertilizer for crop growth. Hence, KU pretreatment combined with enzymatic hydrolysis and fermentation could be a promising green way to cellulosic ethanol production with zero waste emission.

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Enzymatic hydrolysis of microwave alkali pretreated rice husk for ethanol production by Saccharomyces cerevisiae, Scheffersomyces stipitis and their co-culture

Fuel ◽

10.1016/j.fuel.2013.08.072 ◽

2014 ◽

Vol 116 ◽

pp. 699-702 ◽

Cited By ~ 45

Author(s):

Anita Singh ◽

Somvir Bajar ◽

Narsi R. Bishnoi

Keyword(s):

Saccharomyces Cerevisiae ◽

Enzymatic Hydrolysis ◽

Ethanol Production ◽

Rice Husk ◽

Scheffersomyces Stipitis ◽

Hydrolysis Of

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Process optimization for deep eutectic solvent pretreatment and enzymatic hydrolysis of sugar cane bagasse for cellulosic ethanol fermentation

Renewable Energy ◽

10.1016/j.renene.2021.05.131 ◽

2021 ◽

Author(s):

Yao Liu ◽

Xiaojie Zheng ◽

Shunhui Tao ◽

Lei Hu ◽

Xiaodong Zhang ◽

...

Keyword(s):

Enzymatic Hydrolysis ◽

Process Optimization ◽

Sugar Cane ◽

Ethanol Fermentation ◽

Cellulosic Ethanol ◽

Deep Eutectic Solvent ◽

Sugar Cane Bagasse ◽

Hydrolysis Of

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Effects of Biosurfactants on Enzymatic Saccharification and Fermentation of Pretreated Softwood

Molecules ◽

10.3390/molecules25163559 ◽

2020 ◽

Vol 25 (16) ◽

pp. 3559 ◽

Cited By ~ 1

Author(s):

Alfredo Oliva-Taravilla ◽

Cristhian Carrasco ◽

Leif J. Jönsson ◽

Carlos Martín

Keyword(s):

Saccharomyces Cerevisiae ◽

Pseudomonas Aeruginosa ◽

Enzymatic Hydrolysis ◽

Enzymatic Saccharification ◽

Horse Chestnut ◽

Yeast Growth ◽

Cellulose Conversion ◽

Enzymatic Hydrolysis Of Cellulose ◽

Hydrolysis Of Cellulose ◽

Hydrolysis Of

The enzymatic hydrolysis of cellulose is inhibited by non-productive adsorption of cellulases to lignin, and that is particularly problematic with lignin-rich materials such as softwood. Although conventional surfactants alleviate non-productive adsorption, using biosurfactants in softwood hydrolysis has not been reported. In this study, the effects of four biosurfactants, namely horse-chestnut escin, Pseudomonas aeruginosa rhamnolipid, and saponins from red and white quinoa varieties, on the enzymatic saccharification of steam-pretreated spruce were investigated. The used biosurfactants improved hydrolysis, and the best-performing one was escin, which led to cellulose conversions above 90%, decreased by around two-thirds lignin inhibition of Avicel hydrolysis, and improved hydrolysis of pretreated spruce by 24%. Red quinoa saponins (RQS) addition resulted in cellulose conversions above 80%, which was around 16% higher than without biosurfactants, and it was more effective than adding rhamnolipid or white quinoa saponins. Cellulose conversion improved with the increase in RQS addition up to 6 g/100 g biomass, but no significant changes were observed above that dosage. Although saponins are known to inhibit yeast growth, no inhibition of Saccharomyces cerevisiae fermentation of hydrolysates produced with RQS addition was detected. This study shows the potential of biosurfactants for enhancing the enzymatic hydrolysis of steam-pretreated softwood.

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EVALUATION OF ALKALINE PRETREATMENT ON THE ENZYMATIC HYDROLYSIS OF CARNAUBA STRAW RESIDUE

Revista Brasileira de Energias Renováveis ◽

10.5380/rber.v8i3.65666 ◽

2019 ◽

Vol 8 (3) ◽

Author(s):

Alan De Oliveira Campos ◽

Francinaldo Leite Da Silva ◽

Emilianny Rafaely Batista Magalhães ◽

Gorete Ribeiro De Macedo ◽

Everaldo Silvino Dos Santos

Keyword(s):

Enzymatic Hydrolysis ◽

Cellulosic Ethanol ◽

Chemical Characterization ◽

Crystallinity Index ◽

Biomass Pretreatment ◽

Cellulose Conversion ◽

Hydrolysis Of ◽

Potential Use ◽

Second Generation Ethanol

Carnauba (Copernicia prunifera) straw residue generated from production of its wax is rich in cellulose, thus showing a potential use in the production of second generation ethanol. However, the high lignin and hemicellulose load associated with cellulose makes it difficult the enzymatic attack, thus having the need of an adequate pretreatment of this material. The objective of this study was to optimize the enzymatic hydrolysis of carnauba straw residue, focusing on the alkaline biomass pretreatment. Therefore, NaOH solutions at concentrations of 1.0% (w/v) (PA1), 2.0% (w/v) (PA2), 3.0% (w/v) (PA3) and 4.0% (w/v) (PA4) were used. The chemical and physical characterization of natural and pre-treated carnauba straw were according to the NREL, and DRX and FTIR performed analyzes. The materials chemical characterization showed that all the used pretreatments were able to remove a significant amount of lignin and hemicellulose, which can improve the enzymes access, favoring the increase of cellulose conversion. In relation to DRX analysis an increase in crystallinity index happens reaching up to 55.15% after the pretreatment PA4, which may be associated to the removal of hemicellulose and amorphous lignin, related to cellulose. After a period of 96 hours of enzymatic hydrolysis, the PA4 pretreated residue showed the best performance with a cellulosic conversion of 78%. Spite of a slightly lower performance of the residue that presented higher cellulose conversion, the pretreated material PA2 is an alternative to reduce costs in the cellulosic ethanol production.

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Enhanced Enzymatic Hydrolysis of Waste Paper for Ethanol Production Using Separate Saccharification and Fermentation

Applied Biochemistry and Biotechnology ◽

10.1007/s12010-014-1243-1 ◽

2014 ◽

Vol 175 (1) ◽

pp. 25-42 ◽

Cited By ~ 29

Author(s):

Mohamed Guerfali ◽

Adel Saidi ◽

Ali Gargouri ◽

Hafedh Belghith

Keyword(s):

Enzymatic Hydrolysis ◽

Ethanol Production ◽

Waste Paper ◽

Hydrolysis Of

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Ethanol Production from Nondetoxified Dilute-Acid Lignocellulosic Hydrolysate by Cocultures of Saccharomyces cerevisiae Y5 and Pichia stipitis CBS6054

Biotechnology Research International ◽

10.1155/2012/656371 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 13

Author(s):

Ping Wan ◽

Dongmei Zhai ◽

Zhen Wang ◽

Xiushan Yang ◽

Shen Tian

Keyword(s):

Saccharomyces Cerevisiae ◽

Ethanol Production ◽

Ethanol Concentration ◽

Ethanol Yield ◽

Synthetic Medium ◽

Pichia Stipitis ◽

Dilute Acid ◽

Acid Hydrolysate ◽

Issatchenkia Orientalis ◽

Final Ethanol Concentration

Saccharomyces cerevisiae Y5 (CGMCC no. 2660) and Issatchenkia orientalis Y4 (CGMCC no. 2159) were combined individually with Pichia stipitis CBS6054 to establish the cocultures of Y5 + CBS6054 and Y4 + CBS6054. The coculture Y5 + CBS6054 effectively metabolized furfural and HMF and converted xylose and glucose mixture to ethanol with ethanol concentration of 16.6 g/L and ethanol yield of 0.46 g ethanol/g sugar, corresponding to 91.2% of the maximal theoretical value in synthetic medium. Accordingly, the nondetoxified dilute-acid hydrolysate was used to produce ethanol by co-culture Y5 + CBS6054. The co-culture consumed glucose along with furfural and HMF completely in 12 h, and all xylose within 96 h, resulting in a final ethanol concentration of 27.4 g/L and ethanol yield of 0.43 g ethanol/g sugar, corresponding to 85.1% of the maximal theoretical value. The results indicated that the co-culture of Y5 + CBS6054 was a satisfying combination for ethanol production from non-detoxified dilute-acid lignocellulosic hydrolysates. This co-culture showed a promising prospect for industrial application.

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p-NN′-phenylenebismaleimide, a specific cross-linking agent for F-actin

Biochemical Journal ◽

10.1042/bj1751023 ◽

1978 ◽

Vol 175 (3) ◽

pp. 1023-1032 ◽

Cited By ~ 72

Author(s):

P Knight ◽

G Offer

Keyword(s):

Quantitative Analysis ◽

Sodium Dodecyl Sulphate ◽

Actin Filaments ◽

Sodium Dodecyl ◽

Cysteine Residue ◽

Cross Linking ◽

Maximum Value ◽

Cross Links ◽

The Cross ◽

Hydrolysis Of

Covalent cross-links can be inserted between the subunits of F-actin by using p-NN′-phenylenebismaleimide. Cross-linking reaches its maximum value when one molecule of reagent has reacted with each actin subunit. p-NN′-Phenylenebismaleimide reacts initially with a cysteine residue on one subunit, the slower cross-linking reaction involving a lysine residue on a neighbouring subunit. Hydrolysis of the actin-bound reagent limits the extent of cross-linking. Quantitative analysis of the amounts of cross-linked oligomers seen on polyacrylamide gels containing sodium dodecyl sulphate suggests that neither the binding of the reagent to actin nor the formation of cross-links introduces strain into the structure. The cross-links do not join together different F-actin filaments, and evidence is presented that suggests that the cross-links join subunits of the same long-pitched helix.

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