scholarly journals Fermentation alcoolique : observations cinétiques

OENO One ◽  
1979 ◽  
Vol 13 (4) ◽  
pp. 281
Author(s):  
Pierre Strehaiano ◽  
Marc Moreno ◽  
Gérard Goma
Keyword(s):  
Ethanol Production ◽  
Cell Density ◽  
Alcoholic Fermentation ◽  
Initial Level ◽  
Cell Concentration ◽  
Experimental Results ◽  
Initial Concentration ◽  
Mise En Œuvre ◽  
Cette Observation ◽  
Nous Montrons

<p style="text-align: justify;">Dans un premier temps, les concepts cinétiques nécessaires à la compréhension et à la mise en œuvre de la fermentation alcoolique sont discutés.</p><p style="text-align: justify;">Dans un deuxième temps, à la lumière des résultats expérimentaux, nous montrons l'influence de la concentration initiale en sucre (glucose) sur les rendements en biomasse et en éthanol, sur la densité cellulaire et la vitesse moyenne de production d'éthanol. La concentration cellulaire est relativement faible (1,5 à 3 gl<sup>-1</sup>) et ce, quelle que soit la concentration initiale en substrat.</p><p style="text-align: justify;">Après avoir discuté cette observation, nous montrons qu'il n'existe pas de phase exponentielle de croissance et que, lorsque la concentration initiale en sucre augmente, la fraction de temps de fermentation qui s'effectue à un taux de croissance supérieur à 10<sup>-2</sup> µm diminue très sensiblement.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">In that work, kinetic concepts concerning understanding and process of alcoholic fermentation are discussed. Refering to experimental results, it is shown that yield of biomass and of ethanol, cell density and mean speed of ethanol production are in connection with the initial level of glucose. Cell concentration is relatively low without any correlation with the initial concentration of substrate.</p><p style="text-align: justify;">It is shown that exponential growing phase does not exist; when increases the initial level of glucose decreases strongly the time of fermentation occuring with a level growing higher than 10<sup>-2</sup> µm.</p>

scholarly journals Enzymatic Process for Cystoseira barbata Valorization: Ethanol Production and Additional By-Products

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 741
Author(s):  
Doinita-Roxana Cioroiu Tirpan ◽  
Ancaelena Eliza Sterpu ◽  
Claudia Irina Koncsag ◽  
Alina Georgiana Ciufu ◽  
Tănase Dobre
Keyword(s):  
Ethanol Production ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Product Yield ◽  
Liquid Ratio ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Cystoseira Barbata ◽  
Main Factors ◽  
Process Factors

The aim of this study is to evaluate the potential of dried Cystoseira barbata alga for ethanol production through alcoholic fermentation. The influence of the main factors affecting the fermentation are studied in the frame of a 23 factorial experimental plan. The main factors influencing the process are the fermentation temperature (t from 25 °C to 35 °C), the solid to liquid ratio (S/L from 0.040 g/g to 0.080 g/g), and the cellulase ratio (R from 8 U/g d.m to 16 U/g d.m.). The maximum volatile compounds yield of 0.2808 g/g d.m and ethanol yield of 0.0158 g/g d.m were favored by the following experimental conditions: process temperature of 35 °C, solid to liquid ratio of 0.0415, and enzyme ratio of 16 U/g d.m. A statistical model was used to correlate the product yield with the process factors. Additionally, 19 interesting bioactive compounds were found in the enzymatic hydrolysis and alcoholic fermentation broths which seem likely to maintain natural defence mechanisms against diseases and physical disorders.

Process Optimization of Cefradine/ Montmorillionite in Solution Intercalation

2011 ◽  
Vol 306-307 ◽  
pp. 831-834
Author(s):  
Yan Zhao Zhao ◽  
Wen Ji Guo ◽  
Lan Wang
Keyword(s):  
Experimental Design ◽  
Process Optimization ◽  
Reaction Temperature ◽  
Drug Concentration ◽  
Orthogonal Design ◽  
Experimental Results ◽  
Mass Ratio ◽  
Drug Load ◽  
Solution Intercalation ◽  
Initial Concentration

One-factor-at-a-time design and orthogonal design were used in the experimental design to optimize the process of preparation for Cefradine /Montmorillionite composites in solution intercalation. Experimental results indicate that drug initial concentration was the most significant condition for optimal preparation of composites, intercalation time and reaction temperature were not so significant. In our paper, the maximum drug load occurred at reaction temperature of 60°C with the intercalation time of 2h when the drug concentration (mass ratio of cefradine to MMT) was 2:1.

Alcoholic fermentation with high sugar and cell concentration at moderate temperatures using flocculant yeasts

2020 ◽  
Vol 37 (10) ◽  
pp. 1717-1725
Author(s):  
Ana Carolina Tolentino Brandão ◽  
Miriam Maria de Resende ◽  
Eloízio Júlio Ribeiro
Keyword(s):  
Alcoholic Fermentation ◽  
Cell Concentration ◽  
High Sugar

scholarly journals Influence of Lactose Concentration in Bioethanol Production from Cheese Whey

2017 ◽  
Vol 39 (5) ◽  
pp. 533
Author(s):  
Cleidiane Samara Murari ◽  
Débora Cristina Moraes Niz da Silva ◽  
Bruna Lima da Silva ◽  
Vanildo Luiz Del Bianchi
Keyword(s):  
Alcoholic Fermentation ◽  
Cheese Whey ◽  
Ethanol Yield ◽  
Oxygen Demand ◽  
Bioethanol Production ◽  
Organic Substances ◽  
Promising Alternative ◽  
Renewable Source ◽  
Initial Concentration ◽  
Lactose Concentration

The present study aimed the utilization of the cheese whey as substrate for ethanol production by Kluyveromyces marxianus.  Was studied the effect of the initial concentration of cheese whey (M1 57,6 g L-1; M2 45,6 g L-1; M3 32,5 g L-1 e M4 18,8 g L-1) on the alcoholic fermentation. After sterilization, the medium were incubated at 30ºC for 48 hours, performing analysis of lactose, proteins, ethanol, cell growth and chemical oxygen demand. According to the results, the medium M1 (the highest concentration) showed a higher production and productivity of ethanol 16.9 g L-1 and 1.26 g L.h-1, respectively, and also obtained the highest production and productivity of cell of 5.8 g L-1 and 0.40 g L.h-1, respectively. However, in terms of ethanol yield, the most satisfactory result was obtained with the M3 medium with 82.30% in 12 hours of fermentation. The organic substances content has been reduced in relation to COD in the medium M4 in 82.28%, representing a promising alternative for valorization of cheese whey as an effective alternative to obtain a renewable source of biofuel.

Effects of cell density on in vitro glucose metabolism by isolated adipocytes

1993 ◽  
Vol 264 (3) ◽  
pp. E361-E366 ◽  
Author(s):  
M. Digirolamo ◽  
S. V. Thacker ◽  
S. K. Fried
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Glucose Metabolism ◽  
Cell Density ◽  
Acid Concentration ◽  
Cell Concentration ◽  
Fatty Acid Concentration ◽  
Fat Cell ◽  
Cell Concentrations

We studied the effect of variable isolated fat cell concentrations (from 0.17 to 1.25 x 10(6) cells/ml) on rate and pattern of basal and insulin-stimulated glucose metabolism by rat epididymal fat cells. Cell concentration did not affect total glucose utilization, but high cell concentrations increased the absolute and relative conversion of glucose to CO2 and glyceride-fatty acids by two- to threefold and decreased the conversion to lactate, pyruvate, and glyceride-glycerol when compared with values observed at low cell concentration. When effects of adenosine deaminase (ADA) and N-6(2-phenylisopropyl)adenosine (PIA) were examined, addition of ADA to incubated cells produced no significant changes in the rate or pattern of adipocyte glucose metabolism; PIA had a slight and uniform effect on the conversion of glucose to its metabolic products and minimal effect on insulin-stimulated glucose metabolism. Medium free fatty acid concentration did not change during the incubation at various cell density, but intracellular free fatty acids were found to be inversely related to fat cell density in the medium. Thus a variable fat cell density influences the pattern of adipocyte glucose metabolism in vitro. This effect may be due to variable rates of lipolysis and resulting changes in intracellular fatty acid concentration rather than to adenosine per se. This work has practical implications in the need to define cell density when carrying out in vitro measurements of adipocyte glucose conversion to products.

Sign in / Sign up

Export Citation Format

Share Document