scholarly journals Evaluating crude whey for bioethanol production using non-Saccharomyces yeast, Kluyveromyces marxianus

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Asmamaw Tesfaw ◽  
Ebru Toksoy Oner ◽  
Fassil Assefa
Keyword(s):  
Ethanol Production ◽  
Ammonium Sulfate ◽  
Yeast Extract ◽  
Food Production ◽  
Ethanol Productivity ◽  
Bioethanol Production ◽  
Ph Adjustment ◽  
Saccharomyces Yeast ◽  
Food Substrate ◽  
High Ethanol

AbstractEthanol production from non-food substrate is strongly recommended to avoid competition with food production. Whey, which is rich in nutrients, is one of the non-food substrate for ethanol production by Kluyveromyces spp. The purpose of this study was to optimize ethanol from different crude (non-deproteinized, non-pH adjusted, and non-diluted) whey using K. marxianus ETP87 which was isolated from traditional yoghurt. The sterilized and non-sterilized whey were employed for K. marxianus ETP87 substrate to evaluate the yeast competition potential with lactic acid and other microflora in whey. The effect of pH and temperature on ethanol productivity from whey was also investigated. Peptone, yeast extract, ammonium sulfate ((NH4)2SO4), and urea were supplemented to whey in order to investigate the requirement of additional nutrient for ethanol optimization. The ethanol obtained from non-sterilized whey was slightly and statistically lower than sterilized whey. The whey storage at 4 °C didn’t guarantee the constant lactose presence at longer preservation time. Significantly high amount of ethanol was attained from whey without pH adjustment (3.9) even if it was lower than pH controlled (5.0) whey. The thermophilic yeast, K. marxianus ETP87, yielded high ethanol between 30 and 35 °C, and the yeast was able to produce high ethanol until 45 °C, and significantly lower ethanol was recorded at 50 °C. The ammonium sulfate and peptone enhanced ethanol productivity, whereas yeast extract and urea depressed the yeast ethanol fermentation capability. The K. marxianus ETP87, the yeast isolated from traditional yoghurt, is capable of producing ethanol from non-sterilized and non-deproteinized substrates.

scholarly journals Comparison of performances of different fungal laccases in delignification and detoxification of alkali-pretreated corncob for bioethanol production

2021 ◽  
Author(s):  
Shenglong Liu ◽  
Huan Liu ◽  
Chen Shen ◽  
Wei Fang ◽  
Yazhong Xiao ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Productivity ◽  
Phenol Concentration ◽  
Control Treatment ◽  
Bioethanol Production ◽  
Fungal Laccases ◽  
Fermentation Time ◽  
Ph Adjustment ◽  
Fungal Laccase

Abstract The performance of the alkaline fungal laccase PIE5 (pH 8.5) in the delignification and detoxification of alkali-pretreated corncob to produce bioethanol was evaluated and compared with that of the neutral counterpart (rLcc9, 6.5), with the acidic laccase rLacA (4.0) was used as an independent control. Treatment with the three laccases facilitated bioethanol production compared with their respective controls. The lignin contents of alkali-pretreated corncob reduced from 4.06 per cent, 5.06 per cent, and 7.80 per cent to 3.44 per cent, 3.95 per cent, and 5.03 per cent, after PIE5, rLcc9, and rLacA treatment, respectively. However, the performances of the laccases were in the order rLacA > rLcc9 > PIE5 in terms of decreasing total phenol concentration (0.18, 0.36, and 0.67 g/L), boosting ethanol concentration (8.02, 7.51, and 7.31 g/L), and volumetric ethanol productivity (1.34, 0.94, and 0.91 g/L·h), and shortening overall fermentation time. Our results would inform future attempts to improve laccases for ethanol production. Furthermore, based on our data and the fact that additional procedures, such as pH adjustment, are needed during neutral/alkaline fungal laccase treatment, we suggest acidic fungal laccases may be a better choice than neutral/alkaline fungal laccases in bioethanol production.

scholarly journals Optimization of Yeast, Sugar and Nutrient Concentrations for High Ethanol Production Rate Using Industrial Sugar Beet Molasses and Response Surface Methodology

Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 86
Author(s):  
Jean-Baptiste Beigbeder ◽  
Julia Maria de Medeiros Dantas ◽  
Jean-Michel Lavoie
Keyword(s):  
Response Surface Methodology ◽  
Sugar Beet ◽  
Ethanol Production ◽  
Response Surface ◽  
Ethanol Productivity ◽  
Sugar Concentration ◽  
Yeast Fermentation ◽  
Beet Molasses ◽  
Sugar Beet Molasses ◽  
High Ethanol

Among the various agro-industrial by-products, sugar beet molasses produced by sugar refineries appear as a potential feedstock for ethanol production through yeast fermentation. A response surface methodology (RSM) was developed to better understand the effect of three process parameters (concentration of nutrient, yeast and initial sugar) on the ethanol productivity using diluted sugar beet molasses and Saccharomyces cerevisiae yeast. The first set of experiments performed at lab-scale indicated that the addition of 4 g/L of nutrient combined with a minimum of 0.2 g/L of yeast as well as a sugar concentration lower than 225 g/L was required to achieve high ethanol productivities (<15 g/L/d). The optimization allowed to considerably reduce the amount of yeast initially introduced in the fermentation substrate while still maximizing both ethanol productivity and yield process responses. Finally, scale-up assays were carried out in 7.5 and 100 L bioreactors using the optimal conditions: 150 g/L of initial sugar concentration, 0.27 g/L of yeast and 4 g/L of nutrient. Within 48 h of incubation, up to 65 g/L of ethanol were produced for both scales, corresponding to an average ethanol yield and sugar utilization rate of 82% and 85%, respectively. The results obtained in this study highlight the use of sugar beet molasses as a low-cost food residue for the sustainable production of bioethanol.

scholarly journals Development of High-Productivity Continuous Ethanol Production using PVA-Immobilized Zymomonas mobilis in an Immobilized-Cells Fermenter

2014 ◽  
Vol 10 (2) ◽  
Author(s):  
Nurhayati Nurhayati ◽  
Chieh-Lun Cheng ◽  
Jo-Shu Chang
Keyword(s):  
Ethanol Production ◽  
Dilution Rate ◽  
Ethanol Fermentation ◽  
Zymomonas Mobilis ◽  
Immobilized Cells ◽  
Ethanol Productivity ◽  
Glucose Loading ◽  
Continuous Ethanol Fermentation ◽  
Residual Glucose ◽  
High Ethanol

Ethanol as one of renewable energy was being considered an excellent alternative clean-burning fuel to replace gasoline. Continuous ethanol fermentation systems had offered important economic advantages compared to traditional systems. Fermentation rates were significantly improved, especially when continuous fermentation was integrated with cell immobilization techniques to enrich the cells concentration in fermentor. Growing cells of Zymomonas mobilis immobilized in polyvinyl alcohol (PVA) gel beads were employed in an immobilized-cells fermentor for continuous ethanol fermentation from glucose. The glucose loading, dilution rate, and cells loading were varied in order to determine which best condition employed in obtaining both high ethanol production and low residual glucose with high dilution rate. In this study, 20 g/L, 100 g/L, 125 g/L and 150 g/L of glucose concentration and 20% (w/v), 40% (w/v) and 50% (w/v) of cells loading were employed with range of dilution rate at 0.25 to 1 h-1. The most stable production was obtained for 25 days by employing 100 g/L of glucose loading. Meanwhile, the results also exhibited that 125 g/L of glucose loading as well as 40% (w/v) of cells loading yielded high ethanol concentration, high ethanol productivity, and acceptable residual glucose at 62.97 g/L, 15.74 g/L/h and 0.16 g/L, respectively. Furthermore, the dilution rate of 4 hour with 100 g/L and 40% (w/v) of glucose and cells loading was considered as the optimum condition with ethanol production, ethanol productivity and residual glucose obtained were 49.89 g/L, 12.47 g/L/h, and 2.04 g/L, respectively. This recent study investigated ethanol inhibition as well. The present research had proved that high sugar concentration was successfully converted to ethanol. These achieved results were promising for further study.

The influence of the initial concentrations of glucose and yeast extract on the ethanolic fermentation by Pachysolen tannophilus

1990 ◽  
Vol 55 (3) ◽  
pp. 854-866 ◽  
Author(s):  
Rodríguez V. Bravo ◽  
Rubio F. Camacho ◽  
Villasclaras S. Sánchez ◽  
Vico M. Castro
Keyword(s):  
Cell Growth ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Culture Medium ◽  
Ethanolic Fermentation ◽  
Pachysolen Tannophilus ◽  
Significant Component ◽  
Batch Cultures

The ethanolic fermentation in batch cultures of Pachysolen tannophilus was studied experimentally varying the initial concentrations of two of the components in the culture medium: glucose between 0 and 200 g l-1 and yeast extract between 0 and 8 g l-1. The yeast extract appears to be a significant component both in cell growth and for ethanol production.

scholarly journals Factorial Design to Optimize Biosurfactant Production byYarrowia lipolytica

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Gizele Cardoso Fontes ◽  
Priscilla Filomena Fonseca Amaral ◽  
Marcio Nele ◽  
Maria Alice Zarur Coelho
Keyword(s):  
Surface Tension ◽  
Factorial Design ◽  
Ammonium Sulfate ◽  
Yeast Extract ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Biosurfactant Production ◽  
Standard Process ◽  
Emulsification Index ◽  
Full Factorial

In order to improve biosurfactant production byYarrowia lipolyticaIMUFRJ 50682, a factorial design was carried out. A24full factorial design was used to investigate the effects of nitrogen sources (urea, ammonium sulfate, yeast extract, and peptone) on maximum variation of surface tension (ΔST) and emulsification index (EI). The best results (67.7% of EI and 20.9 mNm−1ofΔST) were obtained in a medium composed of 10 g 1−1of ammonium sulfate and 0.5 g 1−1of yeast extract. Then, the effects of carbon sources (glycerol, hexadecane, olive oil, and glucose) were evaluated. The most favorable medium for biosurfactant production was composed of both glucose (4% w/v) and glycerol (2% w/v), which provided an EI of 81.3% and aΔST of 19.5 mN m−1. The experimental design optimization enhancedΔEI by 110.7% andΔST by 108.1% in relation to the standard process.

scholarly journals Effect of Yeast Extract and Vitamin B12 on Ethanol Production from Cellulose by Clostridium thermocellum I-1-B

1992 ◽  
Vol 58 (2) ◽  
pp. 734-736 ◽  
Author(s):  
Kanji Sato ◽  
Shingo Goto ◽  
Sotaro Yonemura ◽  
Kenji Sekine ◽  
Emiko Okuma ◽  
...  
Keyword(s):  
Vitamin B12 ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Clostridium Thermocellum

Bioethanol Production From High Sugary Corn Genotypes by Decreasing Enzyme Consumption

2019 ◽  
pp. 216-240 ◽  
Author(s):  
Hossain Zabed
Keyword(s):  
Biological Sciences ◽  
Literature Review ◽  
Product Quality ◽  
Ethanol Production ◽  
Comparative Evaluation ◽  
Field Experiments ◽  
Bioethanol Production ◽  
Research Questions ◽  
The University ◽  
Expected Outcomes

This is a PhD proposal defended in a 2012-2013 session at the Institute of Biological Sciences, Faculty of Science, University of Malaya, Malaysia. The proposal has been written in accordance with the requirements of the university under the sub-headings: background, problem statement, rationale, hypothesis and research questions, research objectives, literature review, methodology, scope, expected outcomes and concluding remarks, work schedule, and references. This proposal provides a comprehensive study on bioethanol production from corn. First, it discusses development and field experiments of high sugary genotypes (HSGs). Secondly, it provides a comparative evaluation of enzyme consumptions and ethanol production between normal and HSG corn genotypes. Finally, this proposal provides evaluation of the co-product quality for both groups of genotypes. The readers who are interested to conduct any further study on corn-based bioethanol would be benefited from this proposal.

scholarly journals Experimental Design to Improve Cell Growth and Ethanol Production in Syngas Fermentation by Clostridium carboxidivorans

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 59 ◽  
Author(s):  
Carolina Benevenuti ◽  
Alanna Botelho ◽  
Roberta Ribeiro ◽  
Marcelle Branco ◽  
Adejanildo Pereira ◽  
...  
Keyword(s):  
Cell Growth ◽  
Ethanol Production ◽  
Yeast Extract ◽  
Biomass Gasification ◽  
Culture Collection ◽  
Medium Composition ◽  
Syngas Fermentation ◽  
The Cost ◽  
Clostridium Carboxidivorans ◽  
Peptone Yeast Extract Glucose

Fermentation of gases from biomass gasification, named syngas, is an important alternative process to obtain biofuels. Sequential experimental designs were used to increase cell growth and ethanol production during syngas fermentation by Clostridium carboxidivorans. Based on ATCC (American Type Culture Collection) 2713 medium composition, it was possible to propose a best medium composition for cell growth, herein called TYA (Tryptone-Yeast extract-Arginine) medium and another one for ethanol production herein called TPYGarg (Tryptone-Peptone-Yeast extract-Glucose-Arginine) medium. In comparison to ATCC® 2713 medium, TYA increased cell growth by 77%, reducing 47% in cost and TPYGarg increased ethanol production more than four-times, and the cost was reduced by 31%. In 72 h of syngas fermentation in TPYGarg medium, 1.75-g/L of cells, 2.28 g/L of ethanol, and 0.74 g/L of butanol were achieved, increasing productivity for syngas fermentation.

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