scholarly journals Effect of various pretreatment methods on sugar and ethanol production from cellulosic water hyacinth

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 592-606

Effects of acid, alkali, ionic liquid (IL), and microwave-alkali pretreatments on cellulosic water hyacinth (WH) were investigated based on the total reducing sugars (TRS) and ethanol production. For the first time, IL pretreatment with (1-Ethyl-3-methylimidazolium acetate ([EMIM][Ac]) was used for WH, and the efficiency was compared with the other methods. Cellulase and Saccharomyces cerevisiae were fermented together for 72 h. Based on the results, all pretreatment methods effectively increased the sugar content as well as the ethanol yield. Untreated WH had 25 ± 1.5 mg/g of TRS, which was increased to 157 ± 8.2 mg/g, 95 ± 3.1 mg/g, 51 ± 4.2 mg/g, and 45 ± 2.6 mg/g via alkali, microwave-alkali, acid, and IL pretreatments, respectively. The highest TRS level of 402 mg/g was obtained in 24 h and 6.2 ± 0.4 g/L of ethanol in 48 h of fermentation with the alkali-treated WH. The ethanol production was followed by other treatment methods of WH in the order of microwave-alkali, acid, and IL. The results indicated that the ethanol production from WH was related to the type of pretreatment as well as the TRS production.

Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 67
Author(s):  
Fatma Bouaziz ◽  
Amal Ben Abdeddayem ◽  
Mohamed Koubaa ◽  
Francisco J. Barba ◽  
Khawla Ben Jeddou ◽  
...  

This study investigates the feasibility of producing ethanol from date palm seeds. The chemical compositions of three varieties of date seeds were first studied, showing mainly the presence of cellulose and hemicellulose. Ethanol was produced after a pre-treatment of date seeds using acid hydrolysis to extract the cellulosic fraction and to remove the lignin. Producing ethanol by fermentation was performed using the yeast Saccharomyces cerevisiae for 24 h, during which ethanol yield, biomass concentration, and total reducing sugars were recorded. The results obtained showed that the sugar content decreased over time, while ethanol production increased. Indeed, date seeds gave the highest ethanol concentration of 21.57 g/L after 6 h of alcoholic fermentation. These findings proved the feasibility of producing ethanol from date seeds.


2021 ◽  
Vol 34 (1) ◽  
pp. 39-49
Author(s):  
EDNA DAYANE DE BESSA ALMADA ◽  
ANTÔNIO EVAMI CAVALCANTE SOUSA ◽  
FREDERICO ANTÔNIO LOUREIRO SOARES

ABSTRACT Sugarcane is considered as one of the prominent agricultural crops in Brazil, with Goiás being the second largest national producer. During the processing of sugarcane, waste is generated, and one of these is vinasse. The objective of this study was to evaluate the biometric and technological performances of two varieties of sugarcane for different depths and vinasse parceling. Experiments were conducted at Fazenda Boa Sorte, located in the municipality of Carmo do Rio Verde-GO. A randomized block design was used with a subdivided plot containing two varieties of sugarcane (RB 86-7515 and SP 80-1816) and each subplot having three management types for the application of vinasse (M1 20-20 mm, M2 40-0 mm, and M3 30-30 mm) and four repetitions. The applications were performed in the months of May and June (dry period). The variables analyzed were the plant height, number of photosynthetically active green leaves, stem diameter, leaf area, stalk productivity, soluble solids content, broth pol, apparent sucrose content, fiber content, total reducing sugars, and reducing sugars. Analysis of variance was performed on the results obtained using the F test; subsequently, for the significant data, the test of means was performed. The SP 80-1816 variety showed superiority for both the biometric and technological variables. The ethanol yield and total recoverable sugar content were higher for the SP 80-1816 variety, with no difference between the vinasse application management. The vinasse application installment did not show viability.


Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Luis Huezo ◽  
Ajay Shah ◽  
Frederick Michel

Previous studies have shown that pretreatment of corn slurries using ultrasound improves starch release and ethanol yield during biofuel production. However, studies on its effects on the mass transfer of substrates and products during fermentation have shown that it can have both beneficial and inhibitory effects. In this study, the effects of ultrasound on mass transfer limitations during fermentation were examined. Calculation of the external and intraparticle observable moduli under a range of conditions indicate that no external or intraparticle mass transfer limitations should exist for the mass transfer of glucose, ethanol, or carbon dioxide. Fermentations of glucose to ethanol using Saccharomyces cerevisiae were conducted at different ultrasound intensities to examine its effects on glucose uptake, ethanol production, and yeast population and viability. Four treatments were compared: direct ultrasound at intensities of 23 and 32 W/L, indirect ultrasound (1.4 W/L), and no-ultrasound. Direct and indirect ultrasound had negative effects on yeast performance and viability, and reduced the rates of glucose uptake and ethanol production. These results indicate that ultrasound during fermentation, at the levels applied, is inhibitory and not expected to improve mass transfer limitations.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ping Wan ◽  
Dongmei Zhai ◽  
Zhen Wang ◽  
Xiushan Yang ◽  
Shen Tian

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.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ahmed Zahoor ◽  
Katrin Messerschmidt ◽  
Simon Boecker ◽  
Steffen Klamt

Abstract Background Enforced ATP wasting has been recognized as a promising metabolic engineering strategy to enhance the microbial production of metabolites that are coupled to ATP generation. It also appears to be a suitable approach to improve production of ethanol by Saccharomyces cerevisiae. In the present study, we constructed different S. cerevisiae strains with heterologous expression of genes of the ATP-hydrolyzing F1-part of the ATPase enzyme to induce enforced ATP wasting and quantify the resulting effect on biomass and ethanol formation. Results In contrast to genomic integration, we found that episomal expression of the αβγ subunits of the F1-ATPase genes of Escherichia coli in S. cerevisiae resulted in significantly increased ATPase activity, while neither genomic integration nor episomal expression of the β subunit from Trichoderma reesei could enhance ATPase activity. When grown in minimal medium under anaerobic growth-coupled conditions, the strains expressing E. coli’s F1-ATPase genes showed significantly improved ethanol yield (increase of 10% compared to the control strain). However, elevated product formation reduces biomass formation and, therefore, volumetric productivity. We demonstrate that this negative effect can be overcome under growth-decoupled (nitrogen-starved) operation with high and constant biomass concentration. Under these conditions, which mimic the second (production) phase of a two-stage fermentation process, the ATPase-expressing strains showed significant improvement in volumetric productivity (up to 111%) compared to the control strain. Conclusions Our study shows that expression of genes of the F1-portion of E. coli’s ATPase induces ATPase activity in S. cerevisiae and can be a promising way to improve ethanol production. This ATP-wasting strategy can be easily applied to other metabolites of interest, whose formation is coupled to ATP generation.


2011 ◽  
Vol 347-353 ◽  
pp. 2541-2544
Author(s):  
Benjarat Laobussararak ◽  
Warawut Chulalaksananukul ◽  
Orathai Chavalparit

This study was to investigate the fermentation of rice straw using various microorganisms, i.e., the bacterium Zymomonas mobilis, a distillery yeast Saccharomyces cerevisiae and a co-culture of Zymomonas mobilis and Saccharomyces cerevisiae. Rice straw was pretreated with alkaline and followed by enzymatic hydrolysis using cellulase before fermentation by the bacterium and a distillery yeast. Results show that alkali pretreatment is appropriate for rice straw since this pretreatment condition can produce the maximum cellulose of 88.96% and reducing sugar content of 9.18 g/l. Furthermore, the ethanol yield after enzymatic hydrolysis (expressed as % theoretical yield) was 15.94-19.73% for the bacterium, 20.48-35.70% for yeast and 21.56-29.89% for co-culture. Therefore, the distillery yeast was a suitable microorganism for ethanol production from rice straw.


2017 ◽  
Vol 16 (3) ◽  
pp. 388
Author(s):  
CRISTÓBAL SOTO SOLANO ◽  
NIRALDO JOSÉ PONCIANO ◽  
ROGÉRIO FIGUEIREDO DAHER ◽  
RAFAEL AUGUSTO DA COSTA ◽  
PAULO MARCELO DE SOUZA ◽  
...  

 RESUMO - O sorgo sacarino tem potencial de uso como fonte de matéria-prima para a produção de bioetanol. Objetivou-se, com este estudo, analisar o efeito da adubação nitrogenada de cobertura na qualidade do caldo para produção de etanol de quatro cultivares de sorgo sacarino. O experimento foi conduzido em Campos dos Goytacazes- RJ, de janeiro a maio de 2014. Foram estudadas quatro cultivares de sorgo sacarino: BRS 506, BRS 508, BRS 509 e BRS 511 e cinco de doses de nitrogênio (0, 80, 160, 240 e 320 Kg ha-1), aplicadas aos 25 e 45 dias após semeadura. Os resultados mostraram que valor Brix, açúcares redutores totais, açúcares totais recuperáveis, volume do caldo e rendimento de etanol foram afetados pela adubação nitrogenada. Para todas as características, o valor máximo foi obtido pela dose de 240 kg de N ha-1. Entre as cultivares, a BRS 506 mostrou-se superior em produção de caldo e rendimento de etanol. Enquanto a BRS 511 destacou-se nos atributos ART e ATR, e a cultivar BRS 508 sobressaiu-se no valor Brix. A cultivar BRS 506 apresentou melhor resultado combinado, com maior volume de caldo e rendimento de etanol com as doses de 204 e 212 kg N ha-1, respectivamente. Palavras-chave: biocombustíveis, rendimento de álcool carburante, atributos industriais, caracterização da matéria prima, genótipos. QUALITY OF BROTH FOR ETHANOL PRODUCTION IN CULTIVARS OF SACARINE SORGHUM UNDER NITROGEN FERTILIZATION  ABSTRACT - Sweet sorghum has potential as a source of raw material for the production of bioethanol. The objective of this study was to analyze the effect of nitrogen topdressing on the quality of the juice for ethanol production from four cultivars of sorghum. The experiment was conducted in Campos, State of Rio de Janeiro, Brazil, from January to May 2014. Four cultivars of sorghum: BRS 506, BRS 508, BRS 509 and BRS 511 were studied, and five nitrogen rates (0, 80, 160, 240 and 320 kg ha-1), applied to 25 and 45 days after sowing. The results showed that the value Brix, total reducing sugars, total recoverable sugars, broth volume and ethanol yield were affected by nitrogen fertilization. For all features, the maximum value was obtained for the dose of 240 kg N ha-1. Among cultivars, BRS 506 was superior in production of broth and ethanol yield. BRS 511 stood out in the attributes ART and ATR, and BRS 508, in value Brix. BRS 506 had better combined result of higher volume of juice and ethanol yield with doses of 204 and 212 kg N ha-1, respectively Keywords: biofuels, fuel ethanol output, industrial attributes, characterization of raw materials, genotypes.   


Author(s):  
Anuj Kumar Chandel ◽  
Mangamoori Lakshmi Narasu ◽  
Ravinder Rudravaram ◽  
Ravindra Pogaku ◽  
Linga Venkateswar Rao

In the present paper, parametric optimization studies were performed to determine the most influential range of process parameters for maximum ethanol production from Pichia stipitis NCIM3499 by one-at-a-time method under submerged fermentation conditions. Various parameters, such as agitation, pH of medium, temperature and different carbon sources, etc., were taken into consideration. The optimum values of these process parameters were as follows: agitation (200 rpm), pH (5.5), temperature (30°C), and semi-aerobic conditions (150 ml fermentation media in 250 ml Erlenmeyer flask). Among the different carbon substrates tested, glucose and xylose (20±0.21 g/l) showed same ethanol production (8.8±0.35 g/l) with a yield of 0.44±0.11g/g sugar utilized. These process parameters were applied for the ethanol production from de-oiled rice bran (DORB), the left over residue after extraction of oil. It was thermochemically saccharified using sulfuric acid (0.5-5.5% v/v) at 120°C for a fixed residence time of 1h. A maximum of 38.50±0.45 g/l total reducing sugars was obtained at 3.5% v/v H2SO4. This sugar syrup was detoxified by overliming with calcium hydroxide and subsequently fermented with P. stipitis NCIM3499 under the optimized conditions. After 72 h of incubation, DORB hydrolysate (33.50±0.44g/l total reducing sugars) showed maximum ethanol production (12.47±0.26g/l) with the yield 0.42±0.021g/g and fermentation efficiency of 81.74±0.55%. To the best of our knowledge, this is the first report on ethanol production from de-oiled rice bran using P. stipitis NCIM3499.


Author(s):  
José Duarte ◽  
Vera Lourenço ◽  
Belina Ribeiro ◽  
Maria Céu Saagua ◽  
Joana Pereira ◽  
...  

During the last years there has been an increasing interest in using ethanol as a substitute for fossil fuels. The bioethanol used today is mainly produced from sugar cane and cereals, but reducing the production costs of ethanol is still crucial for a viable economic process. Cellulose from vegetable biomass will be the next cheap raw material for second generation fuel ethanol production and agricultural by-products with a low commercial value, as corn stover, corn fiber and cane bagasses would become an attractive feedstock for bioethanol production.In this study, different strains of Saccharomyces cerevisiae have been screened for the ability of bioethanol production. Yeasts were grown in a synthetic liquid medium containing sucrose in batch regime and the growth rates, ethanol and biomass productions were determined as well as their growth ability in cane molasses.The results indicate that a flocculent yeast, isolated in our lab and designated by strain F, was the most promising yeast strain among those tested for continuous ethanol production. This strain was isolated from corn hydrolysates, obtained from a Portuguese distillery facility (DVT, Torres Novas, Portugal) showing highest growth rate (0.49h-1), highest ethanol yield (0.35g/g) and high flocculation capacity.The study on ethanol production in continuous reactor process with the selected yeast strain (strain F) was made on sucrose and cane molasses at different dilution rates (0.05-0.42 h-1). A steady flocculating yeast fluidized bed reactor system was established allowing the functioning of the reactor for 1000 h. Data shows that when the dilution rate rose to 0.42h-1, the highest productivity (20g/Lh) was obtained attaining an ethanol concentration in the reactor of 47g/L for sucrose and molasses media.


2013 ◽  
Vol 15 (2) ◽  
pp. 94-98 ◽  
Author(s):  
Shengdong Zhu ◽  
Pei Yu ◽  
Mingke Lei ◽  
Yanjie Tong ◽  
Lu Zheng ◽  
...  

Ionic liquid (IL) pretreatment of lignocellulosic materials has provided a new technical tool to improve lignocellulosic ethanol production. To evaluate the influence of the residual IL in the fermentable sugars from enzymatic hydrolysis of IL pretreatment of lignocellulosic materials on the subsequent ethanol fermentation, the toxicity of the IL 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) to Saccharomyces cerevisiae AY93161 was investigated. Firstly, the morphological structure, budding and metabolic activity of Saccharomyces cerevisiae AY93161 at different [BMIM]Cl concentrations were observed under an optical microscope. The results show that its single cell morphology remained unchanged at all [BMIM]Cl concentrations, but its reproduction rate by budding and its metabolic activity decreased with the [BMIM]Cl concentration increasing. The half effective concentration (EC50) and the half inhibition concentration (IC50) of [BMIM]Cl to Saccharomyces cerevisiae AY93161 were then measured using solid and liquid suspension culture and their value were 0.53 and 0.39 g.L-1 respectively. Finally, the influence of [BMIM]Cl on ethanol production was investigated. The results indicate that the [BMIM]Cl inhibited the growth and ethanol production of Saccharomyces cerevisiae AY93161. This toxicity study provides useful basic data for further development in lignocellulosic ethanol production by using IL technology and it also enriches the IL toxicity data.


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