Expression of different levels of enzymes from the Pichia stipitis XYL1 and XYL2 genes in Saccharomyces cerevisiae and its effects on product formation during xylose utilisation

1997 ◽  
Vol 48 (2) ◽  
pp. 218-224 ◽  
Author(s):  
M. Walfridsson ◽  
M. Anderlund ◽  
X. Bao ◽  
B. Hahn-Hägerdal
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pichia Stipitis ◽  
Product Formation ◽  
Different Levels

scholarly journals Food Grade Ethanol Production Process of Sorghum Stem Juice Using Immobilized Cells Technique

2015 ◽  
Vol 9 (7) ◽  
pp. 8 ◽  
Author(s):  
Tri Widjaja ◽  
Ali Altway ◽  
Arief Widjaja ◽  
Umi Rofiqah ◽  
Rr Whiny Hardiyati Erlian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Sieve ◽  
Zymomonas Mobilis ◽  
Immobilized Cells ◽  
Ethanol Yield ◽  
Continuous Fermentation ◽  
Continuous Process ◽  
Pichia Stipitis ◽  
Batch Process ◽  
Food Grade

One form of economic development efforts for waste utilization in rural communities is to utilize stem sorghum to produce food grade ethanol. Sorghum stem juice with 150 g/L of sugar concentration was fermented using conventional batch process and cell immobilization continuous process with K-carrageenan as a supporting matrix. The microorganism used was Mutated Zymomonas Mobilis to be compared with a mixture of Saccharomyces Cerevisiae and Pichia Stipitis, and a mixture of Mutated Zymomonas Mobilis and Pichia Stipitis. Ethanol in the broth, result of fermentation process, was separated in packed distillation column. Distilate of the column, still contain water and other impurities, was flown into molecular sieve for dehydration and activated carbon adsorption column to remove the other impurities to meet food grade ethanol specification. The packing used in distillation process was steel wool. For batch fermentation, the fermentation using a combination of Saccharomyces Cerevisiae and Pichia Stipitis produced the best ethanol with 12.07% of concentration, where the yield and the productivity were 63.49%, and 1.06 g/L.h, respectively. And for continuous fermentation, the best ethanol with 9.02% of concentration, where the yield and the productivity were 47.42% and 174.27 g/L.h, respectively, is obtained from fermentation using a combination of Saccharomyces Cerevisiae and Pichia Stipitis also. Fermentation using combination microorganism of Saccharomyces Cerevisiae and Pichia Stipitis produced higher concentration of ethanol, yield, and productivity than other microorganisms. Distillation, molecular sieve dehydration and adsorption process is quite successful in generating sufficient levels of ethanol with relatively low amount of impurities.

scholarly journals Effect of the diet with commercial dry yeast (Saccharomyces cerevisiae) on organoleptic qualities, chemical and biological parameters of common carp (Cyprinus carpio L.)

2019 ◽  
Vol 11 (1) ◽  
pp. 84-89
Author(s):  
N.M. Abdulrahman ◽  
I.H. Al-Refaiee ◽  
H. Ali Mutter
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Common Carp ◽  
Cyprinus Carpio ◽  
Yeast Saccharomyces Cerevisiae ◽  
Fish Flesh ◽  
Common Carp Cyprinus Carpio ◽  
Significant Difference ◽  
Carp Cyprinus Carpio ◽  
Experimental Treatments ◽  
Different Levels

Abstract. The purpose of the present study was to evaluate the replacement of different levels of animal protein concentrate (APC) with a commercial dry yeast Saccharomyces cerevisiae in diets on common carp performance. The experiment was conducted in the fish laboratory of the Department of Animal Production, College of Agricultural Sciences, University of Sulaimani in Kurdistan region of Iraq for the period from 25.07.2015 to 15.10.2015. Starting with a period of acclimatization for 21 days, to test the efficiency of using commercial dry yeast S. cerevisiae as alternative protein source to APC used in the manufacturing of diets for common carp (Cyprinus carpio L.) by using 90 fish at weights ranged 22-42g divided into 15 groups distributed randomly on 15 plastic containers by five treatments with three replicates per each variant. The treatments contain different levels of APC and yeast S. cerevisiae as follows: first treatment (Control T1): 100% APC / 0.00% yeast S. cerevisiae; second treatment (T2): 75% APC / 25% yeast S. cerevisiae; third treatment (T3): 50% APC / 50% yeast S. cerevisiae; fourth treatment (T4): 25% APC / 75% yeast S. cerevisiae and fifth treatment (T5): 0.00% APC / 100% yeast S. cerevisiae. There was no significant difference observed in the value of biological indices for some physiological organs, spleen and Hepatic pancreases and also in the value of the condition factor (CF) between carps from different treatments. The results of the chemical composition of the fish flesh showed significant difference in the moisture of individuals from T4 as compared with these from T2 and T5, T2 was significantly increased in crude protein as compared with other treatments, T5 had significant differences in fat crude as compared with other treatments, T1 and T2 were significantly different in ash as compared with other treatments, T1 was significantly different in carbohydrates as compared with other treatments. The results showed no significant differences observed among experimental treatments in Panel test of tenderness, color, juiciness, flavor and overall acceptance for fish meat.

scholarly journals Influence of the nitrogen source on Saccharomyces cerevisiae anaerobic growth and product formation.

1996 ◽  
Vol 62 (9) ◽  
pp. 3187-3195 ◽  
Author(s):  
E Albers ◽  
C Larsson ◽  
G Lidén ◽  
C Niklasson ◽  
L Gustafsson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nitrogen Source ◽  
Product Formation ◽  
Anaerobic Growth

scholarly journals Microhomology Selection for Microhomology Mediated End Joining in Saccharomyces cerevisiae

Genes ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 284 ◽  
Author(s):  
Kihoon Lee ◽  
Jae-Hoon Ji ◽  
Kihoon Yoon ◽  
Jun Che ◽  
Ja-Hwan Seol ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Budding Yeast ◽  
Product Formation ◽  
Dna Breaks ◽  
End Joining ◽  
Base Pairs ◽  
Circular Chromosome ◽  
Proximal Side ◽  
Selection For ◽  
Insight Into

Microhomology-mediated end joining (MMEJ) anneals short, imperfect microhomologies flanking DNA breaks, producing repair products with deletions in a Ku- and RAD52-independent fashion. Puzzlingly, MMEJ preferentially selects certain microhomologies over others, even when multiple microhomologies are available. To define rules and parameters for microhomology selection, we altered the length, the position, and the level of mismatches to the microhomologies flanking homothallic switching (HO) endonuclease-induced breaks and assessed their effect on MMEJ frequency and the types of repair product formation. We found that microhomology of eight to 20 base pairs carrying no more than 20% mismatches efficiently induced MMEJ. Deletion of MSH6 did not impact MMEJ frequency. MMEJ preferentially chose a microhomology pair that was more proximal from the break. Interestingly, MMEJ events preferentially retained the centromere proximal side of the HO break, while the sequences proximal to the telomere were frequently deleted. The asymmetry in the deletional profile among MMEJ products was reduced when HO was induced on the circular chromosome. The results provide insight into how cells search and select microhomologies for MMEJ in budding yeast.

scholarly journals Ethanol Production from Nondetoxified Dilute-Acid Lignocellulosic Hydrolysate by Cocultures of Saccharomyces cerevisiae Y5 and Pichia stipitis CBS6054

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Ping Wan ◽  
Dongmei Zhai ◽  
Zhen Wang ◽  
Xiushan Yang ◽  
Shen Tian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ethanol Production ◽  
Ethanol Concentration ◽  
Ethanol Yield ◽  
Synthetic Medium ◽  
Pichia Stipitis ◽  
Dilute Acid ◽  
Acid Hydrolysate ◽  
Issatchenkia Orientalis ◽  
Final Ethanol Concentration

Saccharomyces cerevisiae Y5 (CGMCC no. 2660) and Issatchenkia orientalis Y4 (CGMCC no. 2159) were combined individually with Pichia stipitis CBS6054 to establish the cocultures of Y5 + CBS6054 and Y4 + CBS6054. The coculture Y5 + CBS6054 effectively metabolized furfural and HMF and converted xylose and glucose mixture to ethanol with ethanol concentration of 16.6 g/L and ethanol yield of 0.46 g ethanol/g sugar, corresponding to 91.2% of the maximal theoretical value in synthetic medium. Accordingly, the nondetoxified dilute-acid hydrolysate was used to produce ethanol by co-culture Y5 + CBS6054. The co-culture consumed glucose along with furfural and HMF completely in 12 h, and all xylose within 96 h, resulting in a final ethanol concentration of 27.4 g/L and ethanol yield of 0.43 g ethanol/g sugar, corresponding to 85.1% of the maximal theoretical value. The results indicated that the co-culture of Y5 + CBS6054 was a satisfying combination for ethanol production from non-detoxified dilute-acid lignocellulosic hydrolysates. This co-culture showed a promising prospect for industrial application.

scholarly journals Metabolic Engineering of Saccharomyces cerevisiae for Conversion of d-Glucose to Xylitol and Other Five-Carbon Sugars and Sugar Alcohols

2007 ◽  
Vol 73 (17) ◽  
pp. 5471-5476 ◽  
Author(s):  
Mervi H. Toivari ◽  
Laura Ruohonen ◽  
Andrei N. Miasnikov ◽  
Peter Richard ◽  
Merja Penttilä
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Metabolic Engineering ◽  
Growth Medium ◽  
Fold Increase ◽  
Pichia Stipitis ◽  
Xylitol Dehydrogenase ◽  
Sugar Alcohols ◽  
Pentose Sugar ◽  
Encoding Gene ◽  
Pentose Sugars

ABSTRACT Recombinant Saccharomyces cerevisiae strains that produce the sugar alcohols xylitol and ribitol and the pentose sugar d-ribose from d-glucose in a single fermentation step are described. A transketolase-deficient S. cerevisiae strain accumulated d-xylulose 5-phosphate intracellularly and released ribitol and pentose sugars (d-ribose, d-ribulose, and d-xylulose) into the growth medium. Expression of the xylitol dehydrogenase-encoding gene XYL2 of Pichia stipitis in the transketolase-deficient strain resulted in an 8.5-fold enhancement of the total amount of the excreted sugar alcohols ribitol and xylitol. The additional introduction of the 2-deoxy-glucose 6-phosphate phosphatase-encoding gene DOG1 into the transketolase-deficient strain expressing the XYL2 gene resulted in a further 1.6-fold increase in ribitol production. Finally, deletion of the endogenous xylulokinase-encoding gene XKS1 was necessary to increase the amount of xylitol to 50% of the 5-carbon sugar alcohols excreted.

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