scholarly journals Optimization of submerged fermentation conditions to overproduce bioethanol using two industrial and traditional Saccharomyces cerevisiae strains

2019 ◽  
Vol 8 (1) ◽  
pp. 157-162 ◽  
Author(s):  
Reza Shaghaghi-Moghaddam ◽  
Hoda Jafarizadeh-Malmiri ◽  
Parviz Mehdikhani ◽  
Reza Alijanianzadeh ◽  
Sepide Jalalian

Abstract The present study focuses on the overproduction of bioethanol through submerged fermentation. In a batch-scale submerged bioreactor using a traditional and an industrial Saccharomyces cerevisiae (NCYC 4109 and SFO6) strains, the fermentation was accomplished. The effects of the substrate brix (20.50–24.00 °Bx) and inoculum percentage in the initial fermentation solution (15%–45%) as independent variables on bioethanol production (g/l) as the dependent variable were assessed using the response surface methodology. Using the obtained experimental values for the response variable based on experiments for the fermentation parameters, a general model (second-order) with high coefficient of determination values (R2 > 95%) was generated to predict the bioethanol concentrations that were obtained using both yeast strains. The obtained results indicated that the optimum fermentation conditions to overproduce bioethanol (56.14 g/l) using the SFO6 yeast were at the substrate brix and inoculum percentage values of 24.70 °Bx and 26.35%, respectively. However, a higher concentration of bioethanol (53.1 g/l) using the NCYC 4109 yeast strain was obtained at the substrate brix and inoculum percentage values of 24.68 °Bx and 40.07%, respectively.

2018 ◽  
Vol 73 (9-10) ◽  
pp. 361-366 ◽  
Author(s):  
Reza Shaghaghi-Moghaddam ◽  
Hoda Jafarizadeh-Malmiri ◽  
Parviz Mehdikhani ◽  
Sepide Jalalian ◽  
Reza Alijanianzadeh

Abstract Efforts to produce bioethanol with higher productivity in a batch submerged fermentation were made by evaluating the bioethanol production of the five different strains of Saccharomyces cerevisiae, namely, NCYC 4109 (traditional bakery yeast), SFO6 (industrial yeast), TTCC 2956 (hybrid baking yeast) and two wild yeasts, PTCC 5052 and BY 4743. The bioethanol productivity and kinetic parameters for all five yeasts at constant fermentation conditions, during 72 h, were evaluated and monitored. The obtained results indicated that compared to the wild yeasts, both traditional bakery (NCYC 4109) and industrial (SFO6) yeasts had higher bioethanol productivity (0.9 g/L h). Significant (p<0.05) differences between biomass concentration of NCYC 4109 yeast and those of other yeasts 30 h after start of fermentation, and its high bioethanol concentration (59.19 g/L) and yield over consumed sugars (77.25%) were highlighted among all the studied yeasts. Minimum bioethanol productivity was obtained using yeasts PTCC 5052 (0.7 g/L h) and TTCC 2956 (0.86 g/L h). However, maximum yield over consumed sugar was obtained using the yeast TTCC 2956 (79.41%).


2012 ◽  
Vol 621 ◽  
pp. 259-262
Author(s):  
Mei Lin Cui ◽  
Guo Qing He

In this paper, yeast extract concentration, incubation days and inoculation was made as independent variables, the production of intracellular triterpenoids, intracellular polysaccharides and mycelia biomass were made as response values, we set up central composite design of three factors and three levels. Through the analysis of the regression model, we could see that when yeast extract concentration was 1.91%, the inoculation was 14.99% and the incubation days was 4.24d, the production of intracellular triterpenoids, intracellular polysaccharides and mycelia biomass was 100.654 mg/100ml, 58.5968 mg/100ml, 2.39258 g/100ml, respectively.


2018 ◽  
Vol 39 (4) ◽  
pp. 474-482
Author(s):  
Hoang Thi Le Thuong ◽  
Nguyen Quang Hao ◽  
Tran Thi Thuy

Eight yeast strains (denoted as D1 to D8) were isolated from samples of natural fermented pineapple. Strain D8 showed highest alcoholic production at low pH and special aroma of pineapple has been chosen for further study. Taxonomic characterization of strain D8 using morphological, biochemical and molecular biological studies confirmed that strain D8  belong to Saccharomycetaceae family, Saccharomycetales order and Saccharomyces cerevisiae species. Therefore, we named this strain as Saccharomyces cerevisiae D8 for further study on Brandy production from pineapple. Citation: Hoang Thi Le Thuong, Nguyen Quang Hao, Tran Thi Thuy, 2017. Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple. Tap chi Sinh hoc, 39(4): 474- 482. DOI: 10.15625/0866-7160/v39n4.10864.*Corresponding author: [email protected] Received 5 December 2016, accepted 12 August 2017


2019 ◽  
Author(s):  
Chem Int

The new adsorbents were prepared from Moroccan oil shale by chemical and physical process .In this study, experimental Plackett-Burman has been used as a screening method to study six factors for the development of materials to adsorbent basis of oil shale Moroccan. The factors have been identified by two levels, To Know temperature (°C), Processing time (min), mass ratio (m precursor/m acid), Pretreatment mixture the precursor with acid, origin of the raw material and type of the activating agent (H2SO4, H3PO4).And it was chosen as a response The maximum quantity of adsorption of the molecule of Methylene blue (Qads in mg/g) and the specific surface measure by the method bet (Sbet in m2/g), The predicted values were in agreement with the experimental values with a coefficient of determination (R2) of 0.98. The model has been validated by experiments subsequent to optimized conditions. The experimental data processing by software JMP 7 showed that the processing temperature The report of oil shale on the acid and activation time were the important effect on the maximal capacity of adsorption of methylene blue. The sample prepared at 237 °C during 215 min with pre-processing has a maximal capacity of adsorption equal to 54mg/g according to model of adsorption of Langmuir and SBET equal to 143 m2/g.


Beverages ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 27
Author(s):  
Dimitrios Kontogiannatos ◽  
Vicky Troianou ◽  
Maria Dimopoulou ◽  
Polydefkis Hatzopoulos ◽  
Yorgos Kotseridis

Nemea and Mantinia are famous wine regions in Greece known for two indigenous grape varieties, Agiorgitiko and Moschofilero, which produce high quality PDO wines. In the present study, indigenous Saccharomyces cerevisiae yeast strains were isolated and identified from spontaneous alcoholic fermentation of Agiorgitiko and Moschofilero musts in order to evaluate their oenological potential. Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) recovered the presence of five distinct profiles from a total of 430 yeast isolates. The five obtained strains were evaluated at microvinifications trials and tested for basic oenological and biochemical parameters including sulphur dioxide and ethanol tolerance as well as H2S production in sterile grape must. The selected autochthonous yeast strains named, Soi2 (Agiorgitiko wine) and L2M (Moschofilero wine), were evaluated also in industrial (4000L) fermentations to assess their sensorial and oenological characteristics. The volatile compounds of the produced wines were determined by GC-FID. Our results demonstrated the feasibility of using Soi2 and L2M strains in industrial fermentations for Agiorgitiko and Moschofilero grape musts, respectively.


2017 ◽  
Vol 27 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Jolanta Mierzejewska ◽  
Aleksandra Tymoszewska ◽  
Karolina Chreptowicz ◽  
Kamil Krol

2-Phenylethanol (2-PE) is an aromatic alcohol with a rosy scent which is widely used in the food, fragrance, and cosmetic industries. Promising sources of natural 2-PE are microorganisms, especially yeasts, which can produce 2-PE by biosynthesis and biotransformation. Thus, the first challenging goal in the development of biotechnological production of 2-PE is searching for highly productive yeast strains. In the present work, 5 laboratory <i>Saccharomyces cerevisiae</i> strains were tested for the production of 2-PE. Thereafter, 2 of them were hybridized by a mating procedure and, as a result, a new diploid, <i>S. cerevisiae</i> AM1-d, was selected. Within the 72-h batch culture in a medium containing 5 g/L of <smlcap>L</smlcap>-phenylalanine, AM1-d produced 3.83 g/L of 2-PE in a shaking flask. In this way, we managed to select the diploid <i>S. cerevisiae</i> AM1-d strain, showing a 3- and 5-fold increase in 2-PE production in comparison to parental strains. Remarkably, the enhanced production of 2-PE by the hybrid of 2 yeast laboratory strains is demonstrated here for the first time.


2011 ◽  
Vol 65 (2) ◽  
Author(s):  
Mário Mihaľ ◽  
Jozef Markoš ◽  
Vladimír Štefuca

Abstract1-Phenylethanol can be produced by biotransformation of acetophenone using microorganisms. The next step is the separation of biomass from the fermentation solution (e.g. using microfiltration) and then the separation of the product. Membrane extraction was studied in the presented work for this purpose. Equilibria of acetophenone and 1-phenylethanol in the equilibrium system solute-organic solvent-water were investigated for three different organic solvents (heptane, toluene, ethyl acetate). On the basis of this investigation, extraction kinetics of both solutes from the model aqueous solution to the heptane organic phase, using a hollow fiber membrane module, were studied. To simulate the extraction kinetics, mathematical model of an experimental parallel flow hollow fiber contactor is presented and verified using experimental values with good agreement. Extraction kinetics for the investigated organic solvents were simulated and compared using the verified mathematical model and the chosen membrane extraction parameters.


1991 ◽  
Vol 37 (5) ◽  
pp. 397-403 ◽  
Author(s):  
Hiroshi Kuriyama ◽  
Itaru Umeda ◽  
Harumi Kobayashi

Asexual yeast flocculation was studied using strong flocculents of Saccharomyces cerevisiae. The inhibitory effect of cations on flocculation is considered to be caused by competition between those cations and Ca2+ at the binding site of the Ca2+-requiring protein that is involved in flocculation. Inhibition of flocculation by various cations occurred in the following order: La3+, Sr2+, Ba2+, Mn2+, Al3+, and Na+. Cations such as Mg2+, Co2+, and K+ promoted flocculation. This promoting effect may be based on the reduction of electrostatic repulsive force between cells caused by binding of these cations anionic groups present on the cell surface. In flocculation induced by these cations, trace amounts of Ca2+ excreted on the cell surface may activate the corresponding protein. The ratio of Sr2+/Ca2+ below which cells flocculated varied among strains: for strains having the FLO5 gene, it was 400 to 500; for strains having the FLO1 gene, about 150; and for two alcohol yeast strains, 40 to 50. This suggests that there are several different types of cell surface proteins involved in flocculation in different yeast strains. Key words: yeast, flocculation, protein, cation, calcium.


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