scholarly journals Fermentation of irradiated sugarcane must

2003 ◽  
Vol 60 (4) ◽  
pp. 677-681 ◽  
Author(s):  
André Ricardo Alcarde ◽  
Júlio Marcos Melges Walder ◽  
Jorge Horii

Bacillus and Lactobacillus are bacteria that usually contaminate the ethanolic fermentation by yeasts and may influence yeast viability. As microorganisms can be killed by ionizing radiation, the efficacy of gamma radiation in reducing the population of certain contaminating bacteria from sugarcane must was examined and, as a consequence, the beneficial effect of lethal doses of radiation on some parameters of yeast-based ethanolic fermentation was verified. Must from sugarcane juice was inoculated with bacteria of the genera Bacillus and Lactobacillus. The contaminated must was irradiated with 2.0, 4.0, 6.0, 8.0 and 10.0 kGy of gamma radiation. After ethanolic fermentation by the yeast (Saccharomyces cerevisiae) the total and volatile acidity produced during the process were evaluated; yeast viability and ethanol yield were also recorded. Treatments of gamma radiation reduced the population of the contaminating bacteria in the sugarcane must. The acidity produced during the fermentation decreased as the dose rate of radiation increased. Conversely, the yeast viability increased as the dose rate of radiation increased. Gamma irradiation was an efficient treatment to decontaminate the must and improved its parameters related to ethanolic fermentation, including ethanol yield, which increased 1.9%.

2011 ◽  
Vol 347-353 ◽  
pp. 2541-2544
Author(s):  
Benjarat Laobussararak ◽  
Warawut Chulalaksananukul ◽  
Orathai Chavalparit

This study was to investigate the fermentation of rice straw using various microorganisms, i.e., the bacterium Zymomonas mobilis, a distillery yeast Saccharomyces cerevisiae and a co-culture of Zymomonas mobilis and Saccharomyces cerevisiae. Rice straw was pretreated with alkaline and followed by enzymatic hydrolysis using cellulase before fermentation by the bacterium and a distillery yeast. Results show that alkali pretreatment is appropriate for rice straw since this pretreatment condition can produce the maximum cellulose of 88.96% and reducing sugar content of 9.18 g/l. Furthermore, the ethanol yield after enzymatic hydrolysis (expressed as % theoretical yield) was 15.94-19.73% for the bacterium, 20.48-35.70% for yeast and 21.56-29.89% for co-culture. Therefore, the distillery yeast was a suitable microorganism for ethanol production from rice straw.


Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 67
Author(s):  
Fatma Bouaziz ◽  
Amal Ben Abdeddayem ◽  
Mohamed Koubaa ◽  
Francisco J. Barba ◽  
Khawla Ben Jeddou ◽  
...  

This study investigates the feasibility of producing ethanol from date palm seeds. The chemical compositions of three varieties of date seeds were first studied, showing mainly the presence of cellulose and hemicellulose. Ethanol was produced after a pre-treatment of date seeds using acid hydrolysis to extract the cellulosic fraction and to remove the lignin. Producing ethanol by fermentation was performed using the yeast Saccharomyces cerevisiae for 24 h, during which ethanol yield, biomass concentration, and total reducing sugars were recorded. The results obtained showed that the sugar content decreased over time, while ethanol production increased. Indeed, date seeds gave the highest ethanol concentration of 21.57 g/L after 6 h of alcoholic fermentation. These findings proved the feasibility of producing ethanol from date seeds.


2010 ◽  
Vol 156-157 ◽  
pp. 266-271
Author(s):  
Da Wei Zhang ◽  
Wenbin Dong ◽  
Lei Jin ◽  
Jie Zhang ◽  
Yuan Chang Jin

Five preponderant yeast strains (YDJ01, YDJ02, YDJ03, YDJ04 and YDJ05) were isolated from the spontaneous fermentation pear wine as source of yeast for wine making from pear. Ethanol yield of YDJ05 was the highest and its using rapidity of the sugar was the most quickly. YDJ05 was identified as Saccharomyces cerevisiae and named Saccharomyces cerevisiae YDJ05. In addition, the fermentation dynamics of three yeast strains (Saccharomyces cerevisiae YDJ05, “Angle” yeast and Saccharomyces cerevisiae GIM2.39) were studied including single fermentation and associated fermentation. The fermentative behavior of three strains changed in association fermentations (Saccharomyces cerevisiae YDJ05 and “Angle” yeast, Saccharomyces cerevisiae YDJ05 and Saccharomyces cerevisiae GIM2.39). Results indicated that the qualities of pear wines made from association fermentations were better than that of single fermentations. The pear wine fermented associated by Saccharomyces cerevisiae YDJ05 and Saccharomyces cerevisiae GIM2.39 was the best in quality by sensory evaluation among all pear wines whose ethanol concentration was 10.3% (v/v). Saccharomyces cerevisiae YDJ05 and mai could be excellent potential source of strains.


Author(s):  
Pujoyuwono Martosuyono

The objective of this research are to determine the Saccharification and fermentation efficiency of seaweed solid waste hydrolysate by S. cerevisiae in anaerobic condition. The optimum saccharification yield of acid pretreated waste (40.93+1.72%) was obtained after 48 h with a saccharification rate of 0.51±0.02 g/L/h. Higher yield was showed by NaOH pretreated waste (67.29+1.24%) at 24 hours with a saccharification rate of 0.81±0.06 g/L/h. . Fermentation of enzymatic hydrolysates of acid and base pretreated samples with S. cerevisiae produced maximum ethanol 7.52±0.24 g/L and 14.5+0.54 g/L respectively after 72 hours fermentation. Maximum ethanol yield of 0.31±0.03 g/g and 0.40+0.02 g/g sugar respectively for acid and base pretreated samples. The ethanol yields showing that base pretreated sample was producing higher conversion ratio of substrate (80% of theoretical yield) compared to acid pretreated sample (62% of theoretical yield).  


Bioethanol ◽  
2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Kostyantyn V. Dmytruk ◽  
Barbara V. Kshanovska ◽  
Charles A. Abbas ◽  
Andriy Sibirny

AbstractFuel ethanol is an environmentally friendly alternative liquid fuel to the widely used petroleum derived transportation liquid fuels. Since 2007, worldwide fuel ethanol production has increased. Currently ethanol is primarily produced from carbohydrates such as sucrose and starch by fermentation using the yeast Saccharomyces cerevisiae. In this work, new approaches for the selection of S. cerevisiae strains with increased ethanol production from hydrolyzed corn meal are described. An industrial production strain of Saccharomyces cerevisiae AS400 was subjected to positive selection of mutants resistant to toxic concentrations of oxythiamine, trehalose, 3-bromopyruvate, glyoxylic acid, and glucosamine. The selected mutants are characterized by 5-8% increase in ethanol yield (g g-1 of consumed glucose) as compared to the parental industrial ethanol-producing strain. A three-step selection approach that consisted of the use of glyoxylic acid, glucosamine and bromopyruvate resulted in a 12% increase in ethanol yield during fermentation on industrial media. These results indicate that the selected strains are promising candidates for industrial ethanol production.


2019 ◽  
Vol 186 (2-3) ◽  
pp. 191-195
Author(s):  
Barbora Neužilová ◽  
Lukáš Ondrák ◽  
Václav Čuba ◽  
Viliam Múčka

ABSTRACT The protection of Escherichia coli bacteria and the yeast Saccharomyces cerevisiae against UV-C radiation by ethanol was studied. It was found that the fraction of surviving cells increases with increasing ethanol concentration. The specific protection depends on the dose rate, concentration range of ethanol, and it is higher for yeast compared to the bacteria.


2018 ◽  
Vol 35 (1) ◽  
pp. 217-224
Author(s):  
B. Acharya ◽  
B. Dhital

A study was carried out to assess the effect of live yeast Saccharomyces cerevisiae (Nutriferm™) on milk production at National Cattle Research Program Khumaltar Lalitpur from 19 March 2015 to 15 April 2015. Twenty crossbred cattle were selected randomly and divided into five treatment groups. Each group had four animals arranged in Complete Randomized Design (CRD). Among five treatment groups, treatment (T1) was treated with 0.5 kg/MT of live yeast Saccharomyces cerevisiae (SC) incorporated feed, treatment (T2) with 1 kg/MT SC, treatment (T3) with 1.5 kg/MT SC, treatment (T4) with 2 kg/MT SC and treatment (T5) as control without any live yeast inclusion in feed. Supplementation of the live yeast up to seventh day of the trial had statistically non-significant (P>0.05) effect on average milk yield per cattle between the treatments. Response of the yeast on mean milk yield per cattle between the treatments was found statistically different (P<0.05) on fourteenth day and twenty-eight day of the trial. On fourteenth day mean milk yield of control group (T4) was statistically significant with highest dose rate inclusion T4 only but remained non-significant with the rest of the lower dose rate treatments. With further supplementation of the yeast up to 28th day of the trial results showed the statistically significant effect with lower dose rate T2 as well with respect to control group besides T4. Hence, the result of this experiment indicates that supplementation of live yeast for at least 14 days has role in the enhancement of milk production in crossbred dairy cattle with faster effect by dose rate of T4 treatment.


Author(s):  
Karelen Araujo ◽  
Ana Cáceres ◽  
Maria Berradre ◽  
Zulay Mármol ◽  
Johanna Raga ◽  
...  

  El sector vitivinícola mundial se encuentra inmerso en un importante proceso de actualización y renovación. En este contexto es interesante resaltar la actividad y la innovación de muchas bodegas que experimentan con nuevas variedades de uva, la utilización de uvas y levaduras autóctonas, así como con nuevas tecnologías para producir vinos más adaptados al gusto del consumidor. Todos estos cambios conllevan al desarrollo de nuevos productos con propiedades únicas que requieren de un estricto control de calidad. El objetivo del presente trabajo es determinar el perfil fisicoquímico de un vino blanco producido mediante fermentación alcohólica de cepas resultantes de la fusión intergénica de protoplastos de la levadura autóctona Saccharomyces cerevisiae SCVMLUZ 2008 y la levadura comercial Hanseniaspora guilliermondii CECT 11102 (Colección Española de Cultivos Tipo). Se realizaron vinificaciones en blanco con mosto de uva de la variedad Malvasía. Se realizaron los siguientes análisis físico-químicos como sólidos solubles, azúcares, pH, densidad relativa, acidez titulable y volátil, dióxido de azufre total, dióxido de azufre libre y etanol. La cinética de consumo de los azúcares fue más rápida en los bioprocesos realizados con S. cerevisiae y la levadura híbrida (SCHLUZ2014). Todas las levaduras de estudio consumieron glucosa a mayor velocidad que fructosa.  Los resultados obtenidos indican que el vino obtenido con la cepa híbrida cumple con los estándares establecidos por las Organizaciones Nacionales e Internacionales.   Palabras clave: vino blanco, levadura hibrida, consumo de azucares, características fisicoquímicas.   Abstract The world wine sector is immersed in an important process of updating and renewal. In this context, it is interesting to highlight the activity and innovation of many wineries experimenting with new grape varieties, the use of native grapes and yeasts, as well as new technologies to produce wines more adapted to the taste of the consumer. All these changes lead to the development of new products with unique properties that require a strict quality control. The objective of this work is to determine the physicochemical profile of white wine produced by alcoholic fermentation of strains resulting from the intergenic fusion of protoplasts of the indigenous yeast Saccharomyces cerevisiae SCVMLUZ 2008 and the commercial yeast Hanseniaspora guilliermondii CECT 11102 (Colección Española de Cultivos Tipo) White vinifications were made with grape must of the Malvasia variety. The following physical-chemical analyzes were carried out: soluble solids, sugars, pH, relative density, titratable and volatile acidity, total and free sulfur dioxide and ethanol. The kinetics of sugar consumption was faster in the bioprocesses performed with S. cerevisiae and the hybrid yeast (SCHLUZ2014). All the study yeasts consumed glucose at a faster rate than fructose. The results obtained indicate that the wine obtained with the hybrid strain complies with the standards established by the National and International Organizations.   Key words: Key words: white wine, hybrid yeast, consumption of sugars, physicochemical characteristics.


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