scholarly journals Bioethanol-Producing Yeast Isolated from Fermented Cocoa

2021 ◽  
Vol 913 (1) ◽  
pp. 012060
Author(s):  
A. Thontowi ◽  
A.P. Ramadhan ◽  
H. Saputra ◽  
L.N. Kholida ◽  
Fahrurrozi ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Sources ◽  
Culture Collection ◽  
Sugarcane Juice ◽  
Bioethanol Production ◽  
Fermentation Products ◽  
26S Rdna ◽  
Yeast Strains ◽  
The Media ◽  
Optimum Production

Abstract Corn and sugarcane-base bioethanol dominantly contributes to the 25 billion gallons of bioethanol worldwide. Recent researches focused on the potential microbes and biomasses for optimum production. This study is, therefore, aimed to screen the bioethanol generating yeast strains of Biotechnology Culture Collection (BTCC), isolated from chocolate fermentation in several medium containing various carbon sources. A total of 72 yeast strains were grown in the media containing sugarcane juice, sorghum juice, and molasses, which served as carbon sources. Based on 26S rDNA gene analysis, these species were included in 9 genera, encompassing Saccharomyces (63.9%), Hanseniaspora (9.7%), Candida (0.7%), Torulaspora (0.4%), Pichia (0.8%), Issatchenkia (0.1%), Wickerhamomyces (0.3%), Metschnikowia (0.1%), and Rhodotorula (0.1%). Therefore, spectrophotometer UV-Vis was used to analyze cell growth, while the fermentation products (sugars and ethanol) were evaluated using the HPLC, and about 70 strains produced bioethanol. The highest yields were obtained during fermentation, using sugarcane juice, molasses, molasses waste, and sorghum juice, at concentrations of 43, 50, and 7 g/L, respectively. Furthermore, the Saccharomyces cerevisiae strain were the most significant producers, as the genus was able to generate various concentrations from several carbon sources. However, the only genus without the ability to yield any related products during fermentation was Pichia (0.8%). Based on these results, it is necessary to further develop the yeast strains from chocolate fermentation, due to the potential for bioethanol production from biomasses.

scholarly journals A tester system for detecting each of the six base-pair substitutions in Saccharomyces cerevisiae by selecting for an essential cysteine in iso-1-cytochrome c.

Genetics ◽  
1991 ◽  
Vol 128 (1) ◽  
pp. 59-67
Author(s):  
M Hampsey
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sequence Analysis ◽  
Cytochrome C ◽  
Dna Sequence ◽  
Base Pair ◽  
Carbon Sources ◽  
Methyl Methanesulfonate ◽  
Low Frequencies ◽  
Yeast Strains ◽  
Selection Medium

Abstract A collection of isogenic yeast strains that is specifically diagnostic for the six possible base-pair substitutions is described. Each strain contains a single, unique base-pair substitution at the Cys-22 codon of the CYC1 gene, which codes for iso-1-cytochrome c. These mutations encode replacements of the functionally critical Cys-22 and render each strain unable to grow on media containing nonfermentable carbon sources (Cyc-). Specific base-pair substitutions, which restore the Cys-22 codon, can be monitored simply by scoring for reversion to the Cyc+ phenotype. These strains revert spontaneously at very low frequencies and exhibit specific patterns of reversion in response to different mutagens. Only true (CYC1+) revertants were recovered after 7 days on selection medium. The following mutagen specificities were observed: ethyl methanesulfonate and N-methyl-N'-nitro-N-nitrosoguanidine, G.C----A.T; 4-nitroquinoline-1-oxide, G.C----T.A and G.C----A.T; diepoxybutane, A.T----T.A, A.T----G.C and G.C----T.A; 5-azacytidine, G.C----C.G. Methyl methanesulfonate induced all six mutations, albeit at relatively low frequencies, with preference for A.T----T.A and A.T----G.C. Ultraviolet light was the most inefficient mutagen used in this study, consistent with its preference for transition mutations at dipyrimidine sequences reported in other systems. This tester system is valuable as a simple and reliable assay for specific mutations without DNA sequence analysis.

scholarly journals INHIBITION OF THE GROWTH OF TOLERANT YEAST Saccharomyces cerevisiae STRAIN I136 BY A MIXTURE OF SYNTHETIC INHIBITORS

2017 ◽  
Vol 18 (1) ◽  
pp. 17
Author(s):  
Eny Ida Riyanti ◽  
Edy Listanto
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Carbon Sources ◽  
Resistance Mechanism ◽  
Lag Phase ◽  
Cell Factory ◽  
Yeast Saccharomyces Cerevisiae ◽  
Fermentation Products ◽  
Hydroxymethyl Furfural ◽  
Cell Biomass

<p>Biomass from lignocellulosic wastes is a potential source for biobased products.  However, one of the constraints in utilization of biomass hydrolysate is the presence of inhibitors. Therefore, the use of inhibitor-tolerant microorganisms in the fermentation is required. The study aimed to investigate the effect of a mixture of inhibitors on the growth of Saccharomyces cerevisiae strain I136 grown in medium containing synthetic inhibitors (acetic acid, formic acid, furfural, 5-hydroxymethyl furfural/5-HMF, and levulinic acid) in four different concentrations with a mixture of carbon sources, glucose  (50 g.l-1) and xylose (50 g.l-1) at 30oC. The parameters related to growth and fermentation products were observed. Results showed that the strain was able to grow in media containing natural inhibitors (BSL medium) with µmax of 0.020/h. Higher level of synthetic inhibitors prolonged the lag phase, decreased the cell biomass and ethanol production, and specific growth rate. The strain could detoxify furfural and 5-HMF and produced the highest ethanol (Y(p/s) of 0.32 g.g-1) when grown in BSL. Glucose was utilized as its level decreased in a result of increase in cell biomass, in contrast to xylose which was not consumed. The highest cell biomass was produced in YNB with Y (x/s) value of 0.25 g.g-1. The strain produced acetic acid as a dominant side product and could convert furfural into a less toxic compound, hydroxyl furfural. This robust tolerant strain provides basic information on resistance mechanism and would be useful for bio-based cell factory using lignocellulosic materials. </p>

Bioethanol production by imobilized Saccharomyces cerevisiae using sugarcane juice

2019 ◽  
Author(s):  
Leonardo Oura ◽  
◽  
Jose Rodrigues ◽  
Taciani de Jesus ◽  
Lucidio Fardelone ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sugarcane Juice ◽  
Bioethanol Production

scholarly journals Directed Evolution of Saccharomyces cerevisiae for Increased Selenium Accumulation

2018 ◽  
Vol 6 (3) ◽  
pp. 81 ◽  
Author(s):  
Masafumi Yoshinaga ◽  
Stephanie How ◽  
Damien Blanco ◽  
Ian Murdoch ◽  
Matteo Grudny ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cost Efficiency ◽  
Production Efficiency ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Selenium Yeast ◽  
Transgenic Yeast ◽  
Yeast Strains ◽  
Selenium Accumulation ◽  
Nutrient Supplements

Selenium-enriched yeast (selenium yeast) are one of the most popular sources of selenium supplementation used in the agriculture and human nutritional supplements industries. To enhance the production efficiency of selenium yeast, we sought to develop a method to identify, and ultimately select for, strains of yeast with enhanced selenium accumulation capabilities. Selenite resistance of four genetically diverse strains of Saccharomyces cerevisiae was assayed in various conditions, including varying carbon sources, nitrogen sources, and phosphate amounts, and they were correlated with selenium accumulation in a commercially relevant selenium-containing growth medium. Glycerol- and selenite-containing media was used to select for six yeast isolates with enhanced selenite resistance. One isolate was found to accumulate 10-fold greater selenium (0.13 to 1.4 mg Se g−1 yeast) than its parental strain. Glycerol- and selenium-containing medium can be used to select for strains of yeast with enhanced selenium accumulation capability. The methods identified can lead to isolation of industrial yeast strains with enhanced selenium accumulation capabilities that can result in greater cost efficiency of selenium yeast production. Additionally, the selection method does not involve the construction of transgenic yeast, and thus produces yeasts suitable for use in human food and nutrient supplements.

Selection of thermotolerant yeast strains Saccharomyces cerevisiae for bioethanol production

2008 ◽  
Vol 43 (2) ◽  
pp. 120-123 ◽  
Author(s):  
Araque Edgardo ◽  
Parra Carolina ◽  
Rodríguez Manuel ◽  
Freer Juanita ◽  
Jaime Baeza
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Thermotolerant Yeast ◽  
Bioethanol Production ◽  
Yeast Strains ◽  
Selection Of

scholarly journals Valorisation of agroindustrial residues acid hydrolyzates as carbon sources for ethanol production by native yeast strains with different fermentative capabilities//Valorización de hidrolizados ácidos de residuos agroindustriales como fuente de carbono para la producción de etanol por levaduras nativas con capacidades fermentativas diferentes

Biotecnia ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 78-87
Author(s):  
Laura Ivonne Beltrán-Arredondo ◽  
Sandy Rocío Hernández-Leyva ◽  
Ignacio Eduardo Maldonado-Mendoza ◽  
Cuauhtémoc Reyes-Moreno ◽  
Ignacio Contreras-Andrade ◽  
...  
Keyword(s):  
Biomass Yield ◽  
Specific Growth ◽  
Carbon Sources ◽  
Maximum Specific Growth Rate ◽  
Bioethanol Production ◽  
Hemicellulose Hydrolysis ◽  
Yeast Strains ◽  
Agroindustrial Residues ◽  
Attractive Candidate

A profitable, second-generation (2G) bioethanol production process requires the use of the maximum amountof sugars present in the lignocellulosic biomass; among them are those obtained from hemicellulose hydrolysis. An alternative is the search and kinetic characterization of yeasts capable of fermenting xylose to ethanol. In this study, 161 yeasts were isolated from agroindustrial residues, and selected according to best growth in glucose and xylose. Five strains belonging to the genera Candida (C. intermedia and C. parapsilosis), and Wickerhamomyces (W. anomalus) were molecularly identified. The kinetic parameters indicate that C. intermedia CBE002 had the best biomass yield in glucose and xylose (0.21 and 0.35 g/g of substrate), maximum specific growth rate (0.15 and 0.12 h-1) and metabolized both sugars simultaneously, desirable characteristics and rarely found together in other yeasts. Bioethanol production was made possible by C. intermedia (CBE002) from acid hydrolysates of corn stover and mango residues, with yields of 0.31 and 0.26 g/g of substrate, respectively. From the results obtained, this yeast is an attractive candidate to be used in bioethanol 2G production, and to take advantage of the large amount of agroindustrial residues available.RESUMENUn proceso de producción de bioetanol de segunda generación (2G) rentable, requiere el uso del máximo número de azúcares presentes en la biomasa lignocelulósica, como son los obtenidos por hidrólisis de hemicelulosa; para obtenerlo, una alternativa es encontrar levaduras capaces de fermentar eficientemente xilosa a etanol. En el presente trabajo se realizó el aislamiento de 161 levaduras a partir de residuos agroindustriales, se evaluó su capacidad de crecimiento en glucosa y xilosa. Se seleccionaron e identificaron molecularmente cinco de estas cepas pertenecientes a los géneros Candida (C. intermedia, C. parapsilosis) y Wickerhamomyces (W. anomalus). Los parámetros cinéticos demostraron que C. intermedia CBE002 obtuvo el mejor rendimiento de biomasa en glucosa y xilosa (0.21 y 0.35 g/g), la máxima velocidad específica de crecimiento (0.15 y 0.12 h-1) y fue capaz de metabolizar ambos azúcares simultáneamente, característica deseable y poco encontrada en otras levaduras. Fue posible la producción de bioetanol por C. intermedia CBE002 a partir de hidrolizados ácidos de rastrojo de maíz y residuos de mango, con rendimientos de 0.31 y 0.26 g/g de sustrato, respectivamente. Por lo anterior, esta levadura es atractiva para ser empleada en la producción de bioetanol 2G y aprovechar la gran cantidad de residuos agroindustriales disponibles.

The utilization of carbon sources by certain yeast strains

1951 ◽  
Vol 209 (1096) ◽  
pp. 142-142
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Sources ◽  
Tricarboxylic Acid ◽  
Growth Characteristics ◽  
Acid Cycle ◽  
Yeast Strains ◽  
Carbon Substrates ◽  
Optimum Utilization

The growth characteristics of strains of Saccharomyces cerevisiae with different carbon substrates have been studied. The strains examined were able to grow with all the substrates tested, except for one aneurin-exacting strain which failed to metabolize oxalacetic, aconitic, citric and a -ketoglutaric acids. A daptation takes place upon successive subculturing in these substrates. The behaviour observed is compared with that of a typical bacterium, Bact. lactis aerogenes , in the same substrates. Training to some of the substrates may afford adaptation to certain other substrates. The relations found are not all in accordance with expectations based upon the tricarboxylic acid cycle. Some of the strains required training for optimum utilization of glucose. The effect of this training upon their behaviour in a first subculture into acids of the tricarboxylic acid fcycle has been examined. The use of the tricarboxylic acid cycle as a route for glucose metabolism in yeast is con­sidered in the light of the experimental evidence, and the conclusion is reached that this cycle is only one of two or more routes forming an interlocking network by means of which carbon sources can be metabolized in the organism.

The utilization of carbon sources by certain yeast strains

1951 ◽  
Vol 138 (892) ◽  
pp. 375-385 ◽  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Metabolism ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Sources ◽  
Tricarboxylic Acid ◽  
Growth Characteristics ◽  
Acid Cycle ◽  
Yeast Strains ◽  
Carbon Substrates ◽  
Optimum Utilization

The growth characteristics of strains of Saccharomyces cerevisiae with different carbon substrates have been studied. The strains examined were able to grow with all the substrates tested, except for one aneurin-exacting strain which failed to metabolize oxalacetic, aconitic, citric and α -ketoglutaric acids. Adaptation takes place upon successive subculturing in these substrates. The behaviour observed is compared with that of a typical bacterium, Bact. lactis aerogenes , in the same substrates. Training to some of the substrates may afford adaptation to certain other substrates. The relations found are not all in accordance with expectations based upon the tricarboxylic acid cycle. Some of the strains required training for optimum utilization of glucose. The effect of this training upon their behaviour in a first subculture into acids of the tricarboxylic acid cycle has been examined. The use of the tricarboxylic acid cycle as a route for glucose metabolism in yeast is considered in the light of the experimental evidence, and the conclusion is reached that this cycle is only one of two or more routes forming an interlocking network by means of which carbon sources can be metabolized in the organism.

scholarly journals Balance of Activities of Alcohol Acetyltransferase and Esterase in Saccharomyces cerevisiae Is Important for Production of Isoamyl Acetate

1998 ◽  
Vol 64 (10) ◽  
pp. 4076-4078 ◽  
Author(s):  
Kiyoshi Fukuda ◽  
Nagi Yamamoto ◽  
Yoshifumi Kiyokawa ◽  
Toshiyasu Yanagiuchi ◽  
Yoshinori Wakai ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Enzyme Activities ◽  
Isoamyl Alcohol ◽  
Isoamyl Acetate ◽  
Small Scale ◽  
Alcohol Acetyltransferase ◽  
Yeast Strains ◽  
Acetate Accumulation ◽  
Esterase Gene ◽  
Optimum Production

ABSTRACT Isoamyl acetate is synthesized from isoamyl alcohol and acetyl coenzyme A by alcohol acetyltransferase (AATFase) inSaccharomyces cerevisiae and is hydrolyzed by esterases at the same time. We hypothesized that the balance of both enzyme activities was important for optimum production of isoamyl acetate in sake brewing. To test this hypothesis, we constructed yeast strains with different numbers of copies of the AATFase gene (ATF1) and the isoamyl acetate-hydrolyzing esterase gene (IAH1) and used these strains in small-scale sake brewing. Fermentation profiles as well as components of the resulting sake were largely alike; however, the amount of isoamyl acetate in the sake increased with an increasing ratio of AATFase/Iah1p esterase activity. Therefore, we conclude that the balance of these two enzyme activities is important for isoamyl acetate accumulation in sake mash.

scholarly journals Alternative Media Based on Papaya and Fish Extract for Glutathione Production in Saccharomyces cerevisiae

2019 ◽  
Vol 62 (3) ◽  
pp. 178-182
Author(s):  
Nurul Dluha ◽  
Sri Widyarti ◽  
Widodo W
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Alternative Media ◽  
Production Costs ◽  
Harvest Time ◽  
Alternative Source ◽  
Yeast Saccharomyces Cerevisiae ◽  
The Media ◽  
The Cost ◽  
Optimum Production

Glutathione (GSH) is an antioxidant that functions to protect cells from oxidative stress. It is used for medical purposes, as an additive in foods and cosmetics industry. The magnitude of these applications results in increased demand for glutathione every year, however, the cost of glutathione is high. The production of glutathione using an alternative source for the medium and the amino acids used in the media might be the solution for managing the high cost of glutathione production in yeast. This study uses an alternative media based on papaya and fish extract to reduce production costs. The fish extract contains glutamate, cysteine and glycine that can be utilised as a source of amino acid. This study suggested that media based on papaya extract could be employed to produce glutathione in yeast Saccharomyces cerevisiae. Moreover, administration of 5 mg/mL of fish extract could increase the glutathione production up to 36.36% as compared to a control. The optimum production of glutathione was obtained in a harvest time of 44 h culture. Therefore, further investigation by modifying the medium is warranted to produce glutathione in a cost friendly manner in the S. cerevisiae.  

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