scholarly journals Pengaruh Lama Waktu Fermentasi Terhadap Kadar Bioetanol dari Pati Ubi Jalar Kuning (Ipomea batata L)

2017 ◽  
Vol 6 (2) ◽  
pp. 86 ◽  
Author(s):  
Fika Herlina Moede ◽  
Siang Tandi Gonggo ◽  
Ratman Ratman

The sweet potato is yellow is one that the carbohydrate that is high, so it can be used as one of the alternative raw materials for bioethanol. This study aims to determine the levels of ethanol sweet potato is yellow through fermentation with the use of yeast bread with a variety of time 3, 4, 5, 6, dan 7 days at room temperature. The results of the research showed glucose levels derived from the process of hydrolysis using acid HCl 21% were of 4.54% with high levels ethanol that optimum obtained through fermentation use of yeast Saccharomyces cerevisiae of 9.70% over fermentation 5 days.

2021 ◽  
Vol 22 (22) ◽  
pp. 12410
Author(s):  
Daniel P. Brink ◽  
Celina Borgström ◽  
Viktor C. Persson ◽  
Karen Ofuji Osiro ◽  
Marie F. Gorwa-Grauslund

Extension of the substrate range is among one of the metabolic engineering goals for microorganisms used in biotechnological processes because it enables the use of a wide range of raw materials as substrates. One of the most prominent examples is the engineering of baker’s yeast Saccharomyces cerevisiae for the utilization of d-xylose, a five-carbon sugar found in high abundance in lignocellulosic biomass and a key substrate to achieve good process economy in chemical production from renewable and non-edible plant feedstocks. Despite many excellent engineering strategies that have allowed recombinant S. cerevisiae to ferment d-xylose to ethanol at high yields, the consumption rate of d-xylose is still significantly lower than that of its preferred sugar d-glucose. In mixed d-glucose/d-xylose cultivations, d-xylose is only utilized after d-glucose depletion, which leads to prolonged process times and added costs. Due to this limitation, the response on d-xylose in the native sugar signaling pathways has emerged as a promising next-level engineering target. Here we review the current status of the knowledge of the response of S. cerevisiae signaling pathways to d-xylose. To do this, we first summarize the response of the native sensing and signaling pathways in S. cerevisiae to d-glucose (the preferred sugar of the yeast). Using the d-glucose case as a point of reference, we then proceed to discuss the known signaling response to d-xylose in S. cerevisiae and current attempts of improving the response by signaling engineering using native targets and synthetic (non-native) regulatory circuits.


Author(s):  
Anna Ylinen ◽  
Hannu Maaheimo ◽  
Adina Anghelescu-Hakala ◽  
Merja Penttilä ◽  
Laura Salusjärvi ◽  
...  

Abstract Polyhydroxyalkanoates (PHA) provide biodegradable and bio-based alternatives to conventional plastics. Incorporation of 2-hydroxy acid monomers into polymer, in addition to 3-hydroxy acids, offers possibility to tailor the polymer properties. In this study, poly(D-lactic acid) (PDLA) and copolymer P(LA-3HB) were produced and characterized for the first time in the yeast Saccharomyces cerevisiae. Expression of engineered PHA synthase PhaC1437Ps6–19, propionyl-CoA transferase Pct540Cp, acetyl-CoA acetyltransferase PhaA, and acetoacetyl-CoA reductase PhaB1 resulted in accumulation of 3.6% P(LA-3HB) and expression of engineered enzymes PhaC1Pre and PctMe resulted in accumulation of 0.73% PDLA of the cell dry weight. According to NMR, P(LA-3HB) contained D-Lactic acid repeating sequences. For reference, expression of PhaA, PhaB1, and PHA synthase PhaC1 resulted in accumulation 11% poly(hydroxybutyrate) (PHB) of the cell dry weight. Weight average molecular weights of these polymers were comparable to similar polymers produced by bacterial strains, 24.6 kDa, 6.3 kDa, and 1 130 kDa, for P(LA-3HB), PDLA, and PHB, respectively. The results suggest that yeast, as a robust and acid tolerant industrial production organism, could be suitable for production of 2-hydroxy acid containing PHAs from sugars or from 2-hydroxy acid containing raw materials. Moreover, the wide substrate specificity of PHA synthase enzymes employed increases the possibilities for modifying copolymer properties in yeast in the future.


2019 ◽  
Vol 12 (4) ◽  
Author(s):  
L. Levandovsky ◽  
М. Kravchenko

The article presents the results of investigating how the intensity of aerating the medium effects on the cultivation process and the metabolic activity of alcoholic yeast Saccharomyces cerevisiae, strain U-563, in the modern technology of alcohol and baking yeast from molasses. The chemical and technological parameters of media at the aerobic and anaerobic stages of the process, the level of accumulation of the major and secondary products of yeast metabolism, and their enzymatic activity have been determined by methods commonly employed in science and in the practice of alcohol biotechnology. The objects of research were the yeast Saccharomyces cerevisiae, molasses wort, the medium in the process of yeast cultivation, and fermented wash. It has been established that two factors are the most important in the accumulation of alcoholic yeast biomass: the intensity of aerating the medium, and the staged introduction of the substrate during biomass cultivation. The more aerated the medium, the more intensively secondary metabolites of yeast Saccharomyces cerevisiae are formed (glycerol, aldehydes, higher alcohols, volatile acids, and esters) – both at the yeast generation stage and during anaerobic fermentation. When yeast Saccharomyces cerevisiae is grown in a gradient-continuous manner in a battery of series-connected apparatuses, with undiluted substrate (molasses) added by degrees, yeast biosynthesis is significantly enhanced compared to the traditional homogeneous-continuous method. The results obtained indicate the active metabolism of carbohydrates in the Krebs cycle, when the medium is intensively aerated. Besides, the results reveal the high reactivity of aldehydes and esters that results in their transformation into other compounds, and in a great decrease in their amount at the anaerobic stage of the process. However, a progressive increase is observed in glycerol, higher alcohols, and volatile acids, starting from the first yeast generator and up to the last fermentation apparatus, irrespective of the level of aerating the medium during yeast cultivation. These findings can be effectively used to manufacture food, technical, and fuel ethanol industrially from sugar-based raw materials in the course of co-production of alcohol and baking yeast.


Author(s):  
T. S. Kovaleva ◽  
G. V. Agafonov ◽  
A. N. Yakovlev ◽  
S. F. Yakovleva

Saccharomyces cerevisiae yeast is used in the production of ethyl alcohol. The main requirements for yeast used in the production of ethyl alcohol from starch-containing raw materials: alcohol yeast used in the processing of starchy raw materials must have high fermentation activity; complete fermentability of sugars, resistance to metabolic products, resistance to the development of extraneous microflora. Proteolytic enzyme preparation Prolive BS Liquid was used as a source of protease. Kingphos enzyme preparation was used as a source of phytase. The effect of the enzyme preparations of the neutral protease Prolive BS Liquid and Phytase Kingphos on the fermentation activity of alcohol yeast Saccharomyces cerevisiae race XII was studied. The maximum fermentation activity is possessed by yeast cultivated on the wort, obtained using protease and phytase. The duration of the exponential growth phase in the experiment is 14–16 hours, in the control -18–20 hours. The exponential phase is described by the Mono equation. Compared to the yeast in the control, the yeast in the experiment multiplies more intensively, and by 14–16 hours of growth, about 170 million yeast cells accumulate in the culture medium, and the yeast in the control-about 95 million yeast cells by 18–20 h of growth. The specific growth rate was maximum in the logarithmic phase and amounted to 0.35 million cells / cm3 • h in the experimental samples and 0.25 million cells / cm3 • h in the control. It was found that the maximum accumulation of yeast cells was observed when the neutral enzyme Prolive BS Liquid was added to the wort with a dosage of 0.2 units. PS/g of starch and enzyme preparation Phytase Kingfos with a dosage of 0.5 units. FS/g of starch, the yeast cell content in mature yeast reached 170 million cells / cm3 by 16-18 hours of cultivation, the yeast has a high fermentation activity.


2021 ◽  
Vol 15 (3) ◽  
Author(s):  
S. Kovalchuk ◽  
T. Mudrak

Bioethanol production is a key issue that helps meet the growing demand for energy resources and ensure a sustainable economy. A promising direction is producing bioethanol by using the technology of fermentation of high-concentration wort obtained from the dry matter of grain raw materials. The purpose of this work is researching osmophilic races of distiller’s yeast under the conditions of fermentation of high-concentration wort at increased acidity. Selective breeding of a new strain of the yeast Saccharomyces cerevisiae DO-16 has allowed obtaining ethanol producers able to ferment grain wort with the dry matter concentration 24–34% at pH 6.0–3.0, with alcohol accumulation in the fermented wash up to 17% vol.  It has been studied how the pH of wort affects the dynamics of yeast cell synthesis by the distiller’s yeast races Saccharomyces cerevisiae DO-11 and Saccharomyces cerevisiae DO-16. It has been established that at the pH values 2.5, 3.0, 3.5, and 4.0, the concentration of yeast cells in the race Saccharomyces cerevisiae DO-16 was higher by 2.6, 1.7, 1.5, and 1.4 times respectively, as compared with Saccharomyces cerevisiae DO-11. It has been found that culturing industrial yeast of these races at low pH values ​​will provide not only the required sterility of the substrate, but also a high content of yeast cells, which is 250–320 million/cm³. The chemical and technological parameters of the fermented wash obtained by using the yeast races Saccharomyces cerevisiae DO-11 and DO-16 at the wort concentration 20–34% DM have been studied. It has been found that under all research conditions, the yeast of the race Saccharomyces cerevisiae DO-16 synthesised more ethanol than the strain Saccharomyces cerevisiae DO-11 did. The use of a new high-productive strain of Saccharomyces cerevisiae DO-16 will allow fermenting wort with a high ethanol concentration in the wash. It will also reduce the consumption of heat expended on isolating alcohol from the wash and of water expended on cooling, and lessen the amount of post-alcohol stillage.


2016 ◽  
Vol 13 (1) ◽  
pp. 93
Author(s):  
Titin Yulinery ◽  
Ratih M.Dewi

Tes kemampuan adalah salah satu kegiatan penting dalam pengendalian mutu dan jaminan kualitas mikrobiologi laboratorium untuk mengukur kompetensi analis dan analisis uji profisiensi membutuhkan persiapan Model mikroorganisme adalah kualitas standar dan validitas. Mikrobiologi uji kualitas produk kedelai utama diarahkan pada kehadiran Saccharomyces cerevisiae ragi (S. cerevisiae), S. Bailli, S. rouxii dankontaminan bakteri seperti Bacillus dan Deinococcus. Jenis ragi dan bakteri yang terlibat dalam proses dan dapat menjadi salah satu parameter kualitas penting dalam persiapan yang dihasilkan. Jumlah dan viabilitas bakteri dan ragi menjadi parameter utama dalam proses persiapan bahan uji. Jumlah tersebut adalah jumlah minimum yang berlaku dapat dianalisis. Jumlah ini harus dibawah 10 CFU diperlukan untuk menunjukkan tingkat hygienitas proses dan tingkat minimal kontaminasi. Viabilitas bakteri dan bahan tes ragi persiapan untuk tes kemahiran kecap yang diawetkan dengan L-pengeringan adalah teknik Deinococcus radiodurans (D. radiodurans) 16 tahun, 58 tahun S. cerevisiae, dan S. roxii 13 tahun. kata kunci: Viabilitas, Deinococcus, khamir, L-pengeringan, Proficiency AbstractProficiency test is one of the important activities in quality control and quality assurance microbiology laboratory for measuring the competence of analysts and analysis Proficiency test requires a model microorganism preparations are standardized quality and validity. Microbiological test of the quality of the main soy products aimed at thepresence of yeast Saccharomyces cerevisiae (S. cerevisiae), S. bailli, S. rouxii and bacterial contaminants such as Bacillus and Deinococcus. Types of yeasts and bacteria involved in the process and can be one of the important quality parameters in the preparation produced. The number and viability of bacteria and yeasts become themain parameters in the process of test preparation materials. The amount in question is the minimum number that is valid can be analyzed. This amount must be below 10 CFU required to indicate the level of hygienitas process and the minimum level of contamination. Viability of bacteria and yeast test preparation materials for proficiencytest of soy sauce that preserved by L-drying technique is Deinococcus radiodurans ( D. radiodurans ) 16 years, 58 years S. cerevisiae, and S. roxii 13 years. key words : Viability, Deinococcus, Khamir, L-drying, Proficiency


Tsitologiya ◽  
2018 ◽  
Vol 60 (7) ◽  
pp. 555-557 ◽  
Author(s):  
E. A. Alekseeva ◽  
◽  
T. A. Evstyukhina ◽  
V. T. Peshekhonov ◽  
V. G. Korolev ◽  
...  

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