The ingfluence of temperature, pH and aeration on the ethanolic fermentation of glucose by Pachysolen tannophilus

1989 ◽  
Vol 54 (5) ◽  
pp. 1244-1256 ◽  
Author(s):  
F. Camacho Rubio ◽  
V. Bravo Rodríguez ◽  
S. Sánchez Villasclaras ◽  
M. Castro Vico
Keyword(s):  
Ethanol Production ◽  
Ethanol Yield ◽  
Glucose Consumption ◽  
Ethanolic Fermentation ◽  
Pachysolen Tannophilus ◽  
Batch Cultures ◽  
Initial Ph ◽  
Ethanol Yields ◽  
C 30 ◽  
Rates Of Growth

The ethanolic fermentation of 25 g l-1 solutions of glucose in batch cultures of Pachysolen tannophilus has been studied experimentally in terms of three environmental variables: initial pH from 1.5 to 6.5, temperatures of 25 °C, 30 °C and 35 °C and aeration values of Q = 0.150 v/v/min, Q = 0.075 v/v/min and Q = 0 v/v/min (i.e. with air entering through the stirring vortex alone). Using the values for the concentrations of biomass, residual glucose and ethanol produced at intervals throughout the experiments, the maximum specific rates of growth, glucose consumption and ethanol production, together with the biomass and ethanol yields, have been calculated. The most favourable conditions for ethanol production are an initial pH of about 3, temperature of 30 °C and Q = 0 v/v/min. Under these conditions the ethanol yield is approximately 0.36 (g ethanol) (g glucose)-1 and the maximum specific production rate is 1.2 (g ethanol) (g biomass)-1 h-1.

The influence of the initial concentrations of glucose and yeast extract on the ethanolic fermentation by Pachysolen tannophilus

1990 ◽  
Vol 55 (3) ◽  
pp. 854-866 ◽  
Author(s):  
Rodríguez V. Bravo ◽  
Rubio F. Camacho ◽  
Villasclaras S. Sánchez ◽  
Vico M. Castro
Keyword(s):  
Cell Growth ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Culture Medium ◽  
Ethanolic Fermentation ◽  
Pachysolen Tannophilus ◽  
Significant Component ◽  
Batch Cultures

The ethanolic fermentation in batch cultures of Pachysolen tannophilus was studied experimentally varying the initial concentrations of two of the components in the culture medium: glucose between 0 and 200 g l-1 and yeast extract between 0 and 8 g l-1. The yeast extract appears to be a significant component both in cell growth and for ethanol production.

scholarly journals POTENCIAL DE CLONES EXPERIMENTAIS DE BATATA-DOCE PARA PRODUÇÃO DE ETANOL

Nativa ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 352
Author(s):  
Adriano Mendes Lourenço ◽  
Aline Torquato Tavares ◽  
Tiago Alves Ferreira ◽  
Danilo Alves da Silva Porto Lopes ◽  
João Victor Gonçalves Carline ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Ethanol Yield ◽  
Starch Content ◽  
Great Ability ◽  
Ethanol Yields ◽  
Root Starch ◽  
Breeding Selection ◽  
Starch Yield

A batata-doce (Ipomoea batatas (L.) Lam.) tem sido reportada como uma das espécies de planta com grande capacidade de converter biomassa em matéria prima para produção de etanol. O objetivo do trabalho foi avaliar o potencial de clones de batata-doce para produção de etanol. Foram avaliados 60 clones de batata-doce para produtividade de raízes, teor de amido nas raízes, produtividade de amido, coloração da casca e da polpa e o rendimento de etanol. O clone BDTO#122,32 e as cultivares Ana Clara e Carolina Vitória com média de 46,77; 42,75 e 41,25 t ha-¹, respectivamente, foram os que mais conseguiram acumular biomassa na forma de raiz. Os clones que apresentam as maiores médias de produtividade de amido por hectare foram BDTO#144.22 e BDTO#100.23, com valores de 15,46 e 14,16% t ha-1, com rendimentos de etanol de 8,33 e 7,63 m³ ha-¹. Os clones BDTO#144.22 e BDTO#100.23 apresentaram as maiores médias de produtividade de amido por hectare e rendimento de etanol, sendo, portanto, os mais promissores para a produção de etanol.Palavras-chave: Ipomoea batatas (L.) Lam, melhoramento genético, seleção, biocombustível. POTENTIAL OF EXPERIMENTAL CLONES OF SWEET POTATO FOR ETHANOL PRODUCTION ABSTRACT:Sweet potato (Ipomoea batatas (L.) Lam.) Has been reported as one of the plant species with great ability to convert biomass into feedstock for ethanol production. The objective of this work was to evaluate the potential of sweet potato clones for ethanol production. Twenty-six sweet potato clones were evaluated for root productivity, root starch content, starch yield, bark and pulp color, and ethanol yield. Clone BDTO # 122.32 and cultivars Ana Clara and Carolina Vitória averaging 46.77; 42.75 and 41.25 t ha-1, respectively, were the ones that were able to accumulate biomass in the root form. The clones presenting the highest starch productivity per hectare were BDTO # 144.22 and BDTO # 100.23, with values of 15.46 and 14.16% t ha-1, with ethanol yields of 8.33 and 7.63 m³ ha-¹. The clones BDTO # 144.22 and BDTO # 100.23 showed the highest averages of starch productivity per hectare and yield of ethanol, thus being the most promising for the production of ethanol.Keywords: Ipomoea potatoes (L.) Lam, breeding, selection, biofuel.

Construction of Yeast Strain Capable of Co-Fermenting Pentose and Hexose by Protoplast Fusion

2013 ◽  
Vol 781-784 ◽  
pp. 847-851
Author(s):  
Jin Ling Guo ◽  
Da Chun Gong ◽  
Zhi Jun Li ◽  
Zhou Zheng
Keyword(s):  
Ethanol Production ◽  
Protoplast Fusion ◽  
Genetic Stability ◽  
Parental Strain ◽  
Conversion Rate ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Production Capacity ◽  
Pachysolen Tannophilus ◽  
Alcohol Conversion

Saccharomyces cerevisiae R40 and Pachysolen tannophilus P01 were used as the parental strain to construct an engineering strain capable of co-fermenting pentose and hexose by protoplast fusion. A fusant F202 was obtained through inactivating parental protoplasts, screening with YPX solid medium and high glucose liquid medium, ethanol production capacity detecting and identification with PCR-SSR technique. Subsequently, the fermentation performance and genetic stability of F202 was studied. The maximum ethanol production capacity from glucose was 1.47 ml/100 ml with a sugar and alcohol conversion rate 47% which was 11% higher than the parental strain P01. By fermenting xylose the ethanol concentration could achieve to 0.58 ml/100 ml with a sugar and alcohol conversion rate 12%. An ethanol concentration of 1.2 ml/100 ml was obtained by fermenting the mixture of xylose and glucose (mass ratio 1:2). Moreover, no decrease in ethanol yield after 8 generations propagation suggested fustant 202 possessed good genetic stability.

scholarly journals Bioconversion process of source-separated organic waste for ethanol production

2021 ◽  
Author(s):  
Valeriy Bekmuradov
Keyword(s):  
Kinetic Model ◽  
Ethanol Production ◽  
Lignocellulosic Biomass ◽  
Substrate Concentration ◽  
Ethanol Yield ◽  
Ethanol Conversion ◽  
Ethanol Yields ◽  
Environmental Goals ◽  
Ethanol Washing ◽  
Experimental Values

Production of biofuel such as ethanol from lignocellulosic biomass is a beneficial way to meet sustainability, energy security, and environmental goals. Lignocellulosic biomass such as source-separated organic (SSO) waste is particularly attractive since it is widely available, often at a negative cost, reduce the land depletion from using food-based biomass for ethanol production and reduce the amount of generated waste. Therefore, in order to meet the future fuel demands and cope with increasing volume of municipal waste this study was a first attempt to use SSO as a feedstock for ethanol production. The main objectives of the study were: a) to compare standard and modified celluloseorganic- solvent-based lignocellulosic fractionation (COSLIF) pretreatment of SSO waste for ethanol production in terms of enzyme savings, sugar formation and ethanol yields; b) to produce ethanol from SSO by using modified COSLIF pretreatment and fermentation with two different recombinant strains: Z. mobilis 8b and S. cerevisiae DA2416; and c) to develop experimental kinetic model capable of predicting behavior of batch SSCF on SSO waste with different SSO substrate concentrations using Berkeley Madonna program. Based on the obtained results, it was found that SSO is an excellent feedstock material for ethanol conversion. The efficiency of modified COSLIF pretreatment was improved by 20% compared to standard method using ethanol washing of pretreated SSO samples during the experimental procedures instead of acetone. On average, glucose yield from SSO samples pretreated by modified COSLIF was about 90% compared to 10% for untreated samples. S. cerevisiae DA2416 outperformed Z. mobilis 8b on ethanol yields during the fermentation process, with 0.50 g ethanol/g potential sugar fed on SSO in less than 5 days, with a 96% cellulose conversion, totalling in 150 g/L ethanol produced. A kinetic model with newly integrated values of experimentally defined SSO feedstock constants was proven to predict the ethanol yield accurately with substrate concentration ranges of 20 g/L - 50 g/L. Model prediction at higher substrate concentration (e.g. 100 g/L) deviated from the experimental values, suggesting that ethanol inhibition is a major factor in bioethanol conversion.

Changes in ethanol production potential due to species, cultivar and location on the Canadian prairie

2010 ◽  
Vol 90 (2) ◽  
pp. 163-171 ◽  
Author(s):  
J G McLeod ◽  
W E May ◽  
D F Salmon ◽  
K. Sosulski ◽  
J B Thomas ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Ethanol Yield ◽  
Starch Content ◽  
Species Selection ◽  
Western Canada ◽  
Canadian Prairie ◽  
Spring Triticale ◽  
Ethanol Yields ◽  
Small Grains ◽  
Selection Of

In recent years there has been a rapid growth in the fuel ethanol industry, increasing the need for a consistent supply of feedstock. This study was conducted to evaluate the potential of small grains in western Canada to supply feedstock to the ethanol industry. Thirty-one lines and cultivars of Canadian small grains were evaluated: eleven cultivars comprising five classes spring wheat, six cultivars of two and six row barley of feed, malting and hulless classes, eight cultivars of spring triticale and six cultivars of oat were grown at seven locations in western Canada and evaluated as feedstock for ethanol production. Starch concentrations and, for certain grains, β-glucan and pentosans were determined and used to estimate ethanol yields in L t-1 and L ha-1. On average, ethanol yield in L t-1 was wheat > triticale > barley > oat; however, for yield in L ha-1, only oat was inferior. This ranking was consistent across all locations tested. Estimates of ethanol yields indicated that certain cultivars within classes of grains were superior, such as CDC Buck, SWS 109, HY 617 and Pronghorn in the hulless barley, CWSWS, CPS-R and Triticale classes, respectively. Locations that produced the highest level of ethanol in one species tended to produce grain with the highest ethanol yields in the other species. Selection of cultivars with greater starch content, different starch quality and reduced pentosans as well as the advancements in and adoption of new fermentation technologies may lead to greater estimates of ethanol yields of small grain cereals in the future.Key words: Cereal grains, starch, pentosans, β-glucans, ethanol yield

scholarly journals Production of Ethanol from Sugars and Lignocellulosic Biomass byThermoanaerobacterJ1 Isolated from a Hot Spring in Iceland

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jan Eric Jessen ◽  
Johann Orlygsson
Keyword(s):  
Ethanol Production ◽  
Lignocellulosic Biomass ◽  
Hot Spring ◽  
Thermophilic Bacteria ◽  
Product Formation ◽  
Initial Glucose Concentration ◽  
Batch Cultures ◽  
Ethanol Yields ◽  
High Ethanol ◽  
Pretreated Biomass

Thermophilic bacteria have gained increased attention as candidates for bioethanol production from lignocellulosic biomass. This study investigated ethanol production byThermoanaerobacterstrain J1 from hydrolysates made from lignocellulosic biomass in batch cultures. The effect of increased initial glucose concentration and the partial pressure of hydrogen on end product formation were examined. The strain showed a broad substrate spectrum, and high ethanol yields were observed on glucose (1.70 mol/mol) and xylose (1.25 mol/mol). Ethanol yields were, however, dramatically lowered by adding thiosulfate or by cocultivating strain J1 with a hydrogenotrophic methanogen with acetate becoming the major end product. Ethanol production from 4.5 g/L of lignocellulosic biomass hydrolysates (grass, hemp stem, wheat straw, newspaper, and cellulose) pretreated with acid or alkali and the enzymes Celluclast and Novozymes 188 was investigated. The highest ethanol yields were obtained on cellulose (7.5 mM·g−1) but the lowest on straw (0.8 mM·g−1). Chemical pretreatment increased ethanol yields substantially from lignocellulosic biomass but not from cellulose. The largest increase was on straw hydrolysates where ethanol production increased from 0.8 mM·g−1to 3.3 mM·g−1using alkali-pretreated biomass. The highest ethanol yields on lignocellulosic hydrolysates were observed with hemp hydrolysates pretreated with acid, 4.2 mM·g−1.

scholarly journals Engineered Polyploid Yeast Strains Enable Efficient Xylose Utilization and Ethanol Production in Corn Hydrolysates

2021 ◽  
Vol 9 ◽  
Author(s):  
Lulu Liu ◽  
Mingjie Jin ◽  
Mingtao Huang ◽  
Yixuan Zhu ◽  
Wenjie Yuan ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Comprehensive Evaluation ◽  
Ethanol Yield ◽  
Xylose Utilization ◽  
Acid Pretreatment ◽  
Experimental Conditions ◽  
Total Sugars ◽  
Yeast Strains ◽  
Ethanol Yields ◽  
Substrate Concentrations

The reported haploid Saccharomyces cerevisiae strain F106 can utilize xylose for ethanol production. After a series of XR and/or XDH mutations were introduced into F106, the XR-K270R mutant was found to outperform others. The corresponding haploid, diploid, and triploid strains were then constructed and their fermentation performance was compared. Strains F106-KR and the diploid produced an ethanol yield of 0.45 and 0.48 g/g total sugars, respectively, in simulated corn hydrolysates within 36 h. Using non-detoxicated corncob hydrolysate as the substrate, the ethanol yield with the triploid was approximately sevenfold than that of the diploid at 40°C. After a comprehensive evaluation of growth on corn stover hydrolysates pretreated with diluted acid or alkali and different substrate concentrations, ethanol yields of the triploid strain were consistently higher than those of the diploid using acid-pretreatment. These results demonstrate that the yeast chromosomal copy number is positively correlated with increased ethanol production under our experimental conditions.

scholarly journals Ethanolic Fermentation Efficiency of Seaweed Solid Waste hydrolysates by Saccharomyces cerevisiae

2016 ◽  
Vol 11 (1) ◽  
pp. 7
Author(s):  
Pujoyuwono Martosuyono
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Solid Waste ◽  
Ethanol Yield ◽  
Conversion Ratio ◽  
Ethanolic Fermentation ◽  
Fermentation Efficiency ◽  
Theoretical Yield ◽  
Acid And Base ◽  
Ethanol Yields ◽  
Saccharification Yield

The objective of this research are to determine the Saccharification and fermentation efficiency of seaweed solid waste hydrolysate by S. cerevisiae in anaerobic condition. The optimum saccharification yield of acid pretreated waste (40.93+1.72%) was obtained after 48 h with a saccharification rate of 0.51±0.02 g/L/h. Higher yield was showed by NaOH pretreated waste (67.29+1.24%) at 24 hours with a saccharification rate of 0.81±0.06 g/L/h. . Fermentation of enzymatic hydrolysates of acid and base pretreated samples with S. cerevisiae produced maximum ethanol 7.52±0.24 g/L and 14.5+0.54 g/L respectively after 72 hours fermentation. Maximum ethanol yield of 0.31±0.03 g/g and 0.40+0.02 g/g sugar respectively for acid and base pretreated samples. The ethanol yields showing that base pretreated sample was producing higher conversion ratio of substrate (80% of theoretical yield) compared to acid pretreated sample (62% of theoretical yield).  

scholarly journals Potential of Candida glabrata from ragi as a bioethanol producer using selected carbohydrate substrates

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Micky Vincent ◽  
Queentety Johnny ◽  
Dayang Salwani Awang Adeni ◽  
Nurashikin Suhaili
Keyword(s):  
Ethanol Production ◽  
Candida Glabrata ◽  
Ethanol Yield ◽  
Fermented Food ◽  
Ethanol Conversion ◽  
Ethanolic Fermentation ◽  
Different Types ◽  
Notable Increase ◽  
Theoretical Ethanol Yield ◽  
Simultaneous Saccharification

Abstract. Vincent M, Johnny Q, Adeni DSA, Suhaili N. 2020. Potential of Candida glabrata from ragi as a bioethanol producer using selected carbohydrate substrates. Nusantara Bioscience 12: 1-10. The flexibility and efficiency of fermenting microorganisms to convert substrates to ethanol are important factors in achieving high bioethanol yields during ethanolic fermentation. In this study, Candida glabrata, a common yeast found in fermented food, was evaluated in terms of its capability to produce ethanol using different types of carbohydrates, which included simple saccharides (glucose, maltose, sucrose), polysaccharides (starch and cellulose) and complex carbohydrates (total sago effluent, TSE). Our results indicated that C. glabrata was able to efficiently produce ethanol from glucose at 79.84% TEY (Theoretical Ethanol Yield). The ethanol production from sucrose was low, which was only 6.44% TEY, while no ethanol was produced from maltose. Meanwhile, for complex carbohydrate substrates such as starch and cellulose, ethanol was produced only when supplementary enzymes were introduced. Simultaneous Saccharification and Fermentation (SSF) of starch dosed with amylases resulted in an ethanol yield of 55.08% TEY, whilst SSF of cellulose dosed with cellulases yielded a TEY of 31.41%. When SSF was performed on TSE dosed with amylases and cellulases, the highest ethanol production was recorded within 24 h, with a yield of 23.36% TEY. Lactic acid and acetic acid were found to be at minimal levels throughout the fermentation period, indicating an efficient ethanol conversion. A notable increase in C. glabrata biomass was observed in cultures fed with glucose, starch (with supplementary amylases), and TSE (with supplementary amylases and cellulases). The current study indicates that C. glabrata can be used for bioethanol production from glucose, polysaccharides, and complex starchy lignocellulosic substrates such as TSE via SSF.

Improvement in Ethanol Yield from Lignocellulo-Starch Biomass using Saccharomyces cerevisiae alone or its Co-culture with Scheffersomyces stipitis

2020 ◽  
Vol 9 (1) ◽  
pp. 57-76
Author(s):  
Madhanamohanan G. Mithra ◽  
Gouri Padmaja
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Ethanol Yield ◽  
Relative Advantage ◽  
Vegetable Crops ◽  
Fed Batch ◽  
Scheffersomyces Stipitis ◽  
Separate Hydrolysis And Fermentation ◽  
Ethanol Yields ◽  
Sugar Levels

Background: Literature on ethanol production from Lignocellulo-Starch Biomass (LCSB) containing starch besides cellulose and hemicellulose, is scanty. Fed-Batch Separate Hydrolysis And Fermentation (F-SHF) was earlier found more beneficial than Fed-Batch Simultaneous Saccharification and Fermentation (F-SSF). Objective: The study aimed at modification of the saccharification and fermentation strategies by including a prehydrolysis step prior to the SSF and compared the ethanol yields with co-culture fermentation using hexose-fermenting Saccharomyces cerevisiae and pentose-fermenting Scheffersomyces stipitis. Methods: Fed-batch hybrid-SSF and Fed-Batch Separate Hydrolysis and Co-culture Fermentation (F-SHCF) in improving ethanol yield from Steam (ST) or Dilute Sulfuric Acid (DSA) pretreated LCSBs (peels of root and vegetable crops) were studied. Results: There was a progressive build-up of ethanol during F-HSSF up to 72h and further production up to 120h was negligible, with no difference among pretreatments. Despite very high ethanol production in the initial 24h of fermentation by S.cerevisiae under F-SHCF, the further increase was negligible. A rapid hike in ethanol production was observed when S. stipitis was also supplemented because of xylose conversion to ethanol. Conclusion: While ST gave higher ethanol (296-323 ml/kg) than DSA under F-HSSF, the latter was advantageous under F-SHCF for certain residues. Prehydrolysis (24h; 50°C) enhanced initial sugar levels favouring fast fermentation and subsequent saccharification and fermentation occurred concurrently at 37°C for 120h, thus leading to energy saving and hence F-HSSF was advantageous. Owing to the low hemicellulose content in LCSBs, the relative advantage of co-culture fermentation over monoculture fermentation was not significant.

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