The isolation of novel yeast strains for bioethanol 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.

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Feasibility and Sustainability of Bioethanol Production from Starchy restaurants’ Bio-wastes by New Yeast Strains

Waste and Biomass Valorization ◽

10.1007/s12649-017-0184-7 ◽

2018 ◽

Vol 10 (6) ◽

pp. 1617-1626 ◽

Cited By ~ 2

Author(s):

M. Hashem ◽

Tahani Y. A. Asseri ◽

S. A. Alamri ◽

S. A. Alrumman

Keyword(s):

Bioethanol Production ◽

Yeast Strains ◽

New Yeast

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On the Optimization of Fermentation Conditions for Enhanced Bioethanol Yields from Starchy Biowaste via Yeast Co-Cultures

Sustainability ◽

10.3390/su13041890 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1890

Author(s):

Mohamed Hashem ◽

Saad A. Alamri ◽

Tahani A. Y. Asseri ◽

Yasser S. Mostafa ◽

Gerasimos Lyberatos ◽

...

Keyword(s):

Ethanol Yield ◽

Inoculum Size ◽

Small Scale ◽

Bioethanol Production ◽

Fermentation Time ◽

Fermentation Conditions ◽

Batch Cultures ◽

Yeast Strains ◽

Optimization Of Fermentation ◽

The Impact

The present study aims to assess the impact of the type of yeast consortium used during bioethanol production from starchy biowastes and to determine the optimal fermentation conditions for enhanced bioethanol production. Three different yeast strains, Saccharomyces cerevisiae, Pichia barkeri, and Candida intermedia were used in mono- and co-cultures with pretreated waste-rice as substrate. The optimization of fermentation conditions i.e., fermentation time, temperature, pH, and inoculum size, was investigated in small-scale batch cultures and subsequently, the optimal conditions were applied for scaling-up and validation of the process in a 7-L fermenter. It was shown that co-culturing of yeasts either in couples or triples significantly enhanced the fermentation efficiency of the process, with ethanol yield reaching 167.80 ± 0.49 g/kg of biowaste during experiments in the fermenter.

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Selection of thermotolerant yeast strains Saccharomyces cerevisiae for bioethanol production

Enzyme and Microbial Technology ◽

10.1016/j.enzmictec.2008.02.007 ◽

2008 ◽

Vol 43 (2) ◽

pp. 120-123 ◽

Cited By ~ 72

Author(s):

Araque Edgardo ◽

Parra Carolina ◽

Rodríguez Manuel ◽

Freer Juanita ◽

Jaime Baeza

Keyword(s):

Saccharomyces Cerevisiae ◽

Thermotolerant Yeast ◽

Bioethanol Production ◽

Yeast Strains ◽

Selection Of

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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 ◽

10.18633/biotecnia.v22i2.1248 ◽

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.

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Fermented Parkia biglobosa seeds as a nitrogen source supplementation for bioethanol production from cashew apple juice

International Journal of Biological and Chemical Sciences ◽

10.4314/ijbcs.v14i9.37 ◽

2021 ◽

Vol 14 (9) ◽

pp. 3441-3454

Author(s):

Svitlana Nitiema-Yefanova ◽

Cokou Pascal Agbangnan Dossa ◽

Virginie Gbohaïda ◽

Rose Estelle Kanfon ◽

Issiakou Mossi ◽

...

Keyword(s):

Ethanol Production ◽

Apple Juice ◽

Control Sample ◽

Titratable Acidity ◽

Cost Effective ◽

Bioethanol Production ◽

Parkia Biglobosa ◽

Cashew Apple Juice ◽

Yeast Strains ◽

Cashew Apple

Nutritional requirements in the fermentation process are key parameters for optimal yeast development and ethanol production. Natural nutritional supplements rich in nitrogen, phosphorus, sulfur, and micro-elements can improve the performance of yeasts and offer a sustainable, cost-effective, and environmentally friendly alternative to synthetic chemicals. This study aimed at investigating the effect of a natural yeast nutrient (fermented Parkia biglobosa seeds) on bioethanol production from cashew apple juice by Saccharomyces cerevisiae. The proximate and mineral compositions of fermented seeds were evaluated. Their powder was added to yeast medium at a concentration of 4–12 g/L. The behavior of two yeast strains (Angel brand super alcohol (S1) and Angel brand thermal-tolerant alcohol (S2)) was inspected. Titratable acidity, pH, °Brix, and density were evaluated during 144 h of fermentation. Sugar consumption was maximal after 72 and 48 h of fermentation for S1 and S2 yeast strains, respectively. The best ethanol yields of 0.19 and 0.22 g/g were obtained with S1 and S2 yeast strains, respectively, using 12 g/L of nutrients for the first and without nutrient supplementation for the second (control sample). The non-conventional nutrients from fermented P. biglobosa seeds seem to be favorablefor ethanol production using only S1 yeast strain.

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