Definition of optimum basic nutrients ratio in media for bioethanol production with immobilised yeast cells

2017 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Zorana Rončević ◽  
Jelena Dodić ◽  
Jovana Grahovac ◽  
Siniša Dodić ◽  
Bojana Bajić ◽  
...  
Keyword(s):  
Yeast Cells ◽  
Bioethanol Production ◽  
Definition Of ◽  
Immobilised Yeast

Definition of optimum basic nutrients ratio in media for bioethanol production with immobilised yeast cells

2017 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Damjan Vučurović ◽  
Bojana Bajić ◽  
Siniša Dodić ◽  
Jovana Grahovac ◽  
Jelena Dodić ◽  
...  
Keyword(s):  
Yeast Cells ◽  
Bioethanol Production ◽  
Definition Of ◽  
Immobilised Yeast

Bioethanol production from corn cob using immobilised yeast cells

2010 ◽  
Vol 150 ◽  
pp. 151-151 ◽  
Author(s):  
T. Samuel ◽  
S.E. Iyuke ◽  
C.S. Yah ◽  
K. Rumbold
Keyword(s):  
Yeast Cells ◽  
Bioethanol Production ◽  
Corn Cob ◽  
Immobilised Yeast

scholarly journals Candida albicansdispersed cells signify a developmental state distinct from biofilm and planktonic phases

2018 ◽  
Author(s):  
Priya Uppuluri ◽  
Maikel Acosta Zaldivar ◽  
Matthew Z Anderson ◽  
Matthew J. Dunn ◽  
Judith Berman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Carbon Sources ◽  
Developmental State ◽  
Yeast Cells ◽  
Direct Access ◽  
Biofilm Model ◽  
Definition Of ◽  
Biofilm Development ◽  
External Signals ◽  
Dispersed Cells

AbstractCandida albicanssurface-attached biofilms are sites of amplification of an infection through continuous discharge of cells capable of initiating new infectious foci. Yeast cells released from biofilms on intravenous catheters have direct access to the bloodstream. We previously reported that dispersed cells are largely lateral yeast cells that originate from the hyphal layers of the biofilm. Compared to their planktonic counterparts, these biofilm-dispersed yeast cells displayed enhanced virulence-associated gene expression and drug resistance. Little is known about the molecular properties of dispersed cells. We found that the inducer of dispersal,PES1, genetically interacts with the repressor of filamentation,NRG1, in a manner that supports a genetic definition of dispersed cells as yeast. We combined a flow biofilm model with RNA sequencing technology, to identify transcriptomic characteristics of freshly dispersed yeast cells versus biofilms or age-matched planktonic yeast cells growing in glucose-rich medium. Dispersed cells largely inherited a biofilm-like mRNA profile but with one stark difference: dispersed cells were transcriptionally reprogrammed to metabolize alternative carbon sources, while their sessile parents expressed glycolytic genes, despite exposure to the same nutritional signals. Our studies hence define dispersal cell production as an intrinsic step of biofilm development which generates propagules capable of colonizing distant host sites. This developmental step anticipates the need for virulence-associated gene expression before experiencing the associated external signals.

scholarly journals Stability Studies of Immobilized Saccharomyces Cerevisiae in Calcium Alginate and Carrageenan Beads

2017 ◽  
Vol 2 (4) ◽  
pp. 10 ◽  
Author(s):  
Rahmath Abdulla ◽  
Warda Abdul Ajak ◽  
Siti Hajar ◽  
Eryati Derman
Keyword(s):  
Calcium Alginate ◽  
Alternative Fuels ◽  
Fossil Fuels ◽  
Alginate Beads ◽  
Yeast Cells ◽  
Bioethanol Production ◽  
Stability Studies ◽  
Fuel Prices ◽  
The Stability ◽  
Liquid Biofuel

Currently the resources for fossil fuels are depleting together with increase in fuel prices. This has urged the need for cheaper alternative fuels especially biofuels. The production of the most common liquid biofuel which is bioethanol using immobilized yeast cells is an approach taken to increase its demand in the world’s market. There are various methods for the immobilization of yeast cells; however before they can be applied in the industry the stability of the immobilization technology must be investigated. This research aims to study the stabilities of immobilized S. cerevisiae in calcium alginate and carrageenan beads for bioethanol production. The S. cerevisiae was immobilized in calcium alginate and carrageenan beads using entrapment method. Next, screening for the optimal concentration of sodium alginate and semi refined carrageenan matrices were determined by employing fermentation and bioethanol quantification using GC-MS. Concentrations of 2% (w/v) calcium alginate and 2% (w/v) semi refined carrageenan beads were identified to produce the highest bioethanol yield which were 0.286 g/mL and 0.065 g/mL respectively. The two beads were then chosen to be tested in various stability studies with respect to bioethanol production such as storage stability, reusability, pH, thermaland permeability test. It was found out that a concentration of 2% (w/v) calcium alginate beads were more stable as immobilization matrix for S. cerevisiae  as compared to 2% (w/v) semi refined carrageenan.

Reactors for ethanol production using immobilised yeast cells

2007 ◽  
Vol 39 (2) ◽  
pp. 75-84 ◽  
Author(s):  
Nasibuddin Qureshi ◽  
J. S. Pai ◽  
D. V. Tamhane
Keyword(s):  
Ethanol Production ◽  
Yeast Cells ◽  
Immobilised Yeast

A Novel Immobilization Method of Saccharomyces cerevisiae on Fermentation of Nipa Palm Sap for Fuel Grade Bioethanol Production

2020 ◽  
Vol 849 ◽  
pp. 53-57
Author(s):  
Chairul ◽  
Evelyn ◽  
Syaiful Bahri ◽  
Ella Awaltanova
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Sugar Content ◽  
Yeast Cells ◽  
Eastern Coast ◽  
Bioethanol Production ◽  
Fermentation Time ◽  
Immobilized Yeast ◽  
Immobilized Yeast Cells ◽  
Nipa Palm

Nipa palm (Nypa fruticans) spreads abundantly in the mangrove forests of eastern coast of Sumatera Island, Indonesia. Nipa palm sap can be used as a very high-gravity (VHG) substrate for fermentation. In this research, batch fermentation of nipa sap with initial sugar content of 262.713 mg/ml using immobilized Saccharomyces cerevisiae yeast cells was studied. Immobilization of the yeasts in Na-alginate by droplet method and addition of 0.2% v/v Tween 80 and 0.5g/l ergosterol to the immobilized cells were first carried out. Then, the effect of cells weight percentage (5, 10, 15, and 20% w/v) and fermentation time (24, 36, 48, 60, 72, 84, and 96 hrs) on the bioethanol production were investigated. After, the analysis of bioethanol concentration was investigated using Gas Chromatography. The bioethanol production increased with the fermentation time until reaching a maximum value at all cell weights. Except with the 20% w/v, this peak was followed by a decrease in the bioethanol production at cell weights of 5, 10, and 15% w/v. This phenomenon may be explained by degradation of bioethanol into acetic acid resulting in the decreased concentration at the end of fermentation. The formation of acetic acid was characterized by decreases in the pH values of the fermentation medium. On the contrary, the bioethanol level tended to increase until the end of fermentation with the immobilized yeast cells of 20% w/v. High number of available immobilized yeast cells at the end of fermentation, accumulation of bioethanol produced at earlier times, and no further conversion of bioethanol to acetic acid could be the reasons for this increase. The optimum conditions for bioethanol production were 20% w/v cell weight and 96 hr fermentation time, at bioethanol concentration of 17.57% v/v.

scholarly journals Optimization of an Industrial Medium from Molasses for Bioethanol Production Using the Taguchi Statistical Experimental-Design Method

Fermentation ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 14 ◽  
Author(s):  
Farshad Darvishi ◽  
Nooshin Abolhasan Moghaddami
Keyword(s):  
Experimental Design ◽  
Taguchi Method ◽  
Yeast Strain ◽  
Design Method ◽  
Yeast Cells ◽  
Statistical Experimental Design ◽  
Bioreactor Culture ◽  
Bioethanol Production ◽  
Anaerobic Conditions ◽  
Experimental Design Method

The production of bioethanol as a clean liquid fuel in a cost-effective way is highly desired by global energetics. Sugar beet molasses is a renewable and cheap substrate for the production of biotechnological products. Therefore, the aim of the current study was the optimization of an industrial medium from molasses for bioethanol production using the Taguchi statistical experimental-design method. First, the growth rate of yeast cells and the amount of ethanol produced by the Saccharomyces cerevisiae strain sahand 101 were investigated in aerobic and aerobic–anaerobic conditions. The yeast strain produced 8% (v/v) bioethanol in a medium containing molasses with 18% Brix in aerobic–anaerobic conditions. The main factors of the medium, including molasses, ammonium sulfate, urea, and pH, were optimized for the increase of bioethanol production by the Taguchi method. Bioethanol production reached 10% (v/v) after optimization of the medium in flask culture. The yeast strain produced 11% (v/v) bioethanol in the bioreactor culture containing the optimized medium, which is an acceptable amount of bioethanol produced from molasses at the industrial scale. The results showed that the Taguchi method is an effective method for the design of experiments aiming to optimize the medium for bioethanol production by reducing the number of experiments and time.

scholarly journals Fermentation of Sweet Sorghum Syrup Under Reduced Pressure for Bioethanol Production

2020 ◽  
Vol 14 (1) ◽  
pp. 235-245
Author(s):  
Oleksii I. Volodko ◽  
Tetiana S. Ivanova ◽  
Ganna I. Kulichkova ◽  
Kostyantyn M. Lukashevych ◽  
Yaroslav B. Blume ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Sweet Sorghum ◽  
Production Efficiency ◽  
High Efficiency ◽  
Green Energy ◽  
Yeast Cells ◽  
Vacuum Extraction ◽  
Bioethanol Production ◽  
Nitrogen And Phosphorus ◽  
Reduced Pressure

Background: Production of bioethanol from sweet sorghum (Sorghum saccharatum) is a promising “green” energy source that can help to reduce energy dependence on petroleum products, to decrease greenhouse gas emissions, and fight environmental pollution. As an additional benefit, it can promote the exploitation of new uncultivated agricultural lands and favor establishing integrated agro-industrial energy independent enterprises. The alcoholic fermentation under reduced pressure may prevent the accumulation of high ethanol concentrations in the cultured broth and thus may create favorable conditions for the highest productivity of yeast Saccharomyces cerevisiae. Objective: Elaboration of optimal conditions for sweet sorghum syrup fermentation under reduced pressure. Aim: To determine the parameters of sweet sorghum syrup fermentation by S. cerevisiae under the conditions of constant and periodic reduced pressure for the highest bioethanol production efficiency. Methods: The sweet sorghum was grown in a temperate continental climate region of Northern Ukraine. The parameters of diluted stem syrup and S. cerevisiae fermentation under reduced and atmospheric pressure were established and controlled by chemical, biochemical and physicochemical methods. The yeast cells were dyed with methylene blue and counted using a microscope and a Neubauer counting chamber. The obtained data have been statistically analyzed. Results: It has been established that a periodic vacuum extraction with short-term heating of the medium to the boiling point is the most promising procedure for bioethanol production. Periodically reduced pressure fermentation of sweet sorghum diluted syrup resulted in 55% higher bioethanol productivity compared to atmospheric pressure fermentation. Such treatment enables to maintain the concentration of ethanol in the medium below 5.5% vol., which does not significantly inhibit the productivity of industrial yeast strains and allows adding a nutrient with the subsequent continuation of the cultivation process. The resulting distillate requires less energy for further dehydration. Conclusion: The sweet sorghum syrup does not contain substances that inhibit yeast cells although nitrogen and phosphorus supplements are required to support efficient S. cerevisiae growth. The optimal technology, elaborated in this research, consists of repeated cycles of fermentation under reduced pressure (to the level of vacuum) for boiling the cultured broth. This technology provides the highest bioethanol output, high efficiency, and productivity of the overall process.

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