scholarly journals Oenological Potential of Autochthonous Saccharomyces cerevisiae Yeast Strains from the Greek Varieties of Agiorgitiko and Moschofilero

Beverages ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 27
Author(s):  
Dimitrios Kontogiannatos ◽  
Vicky Troianou ◽  
Maria Dimopoulou ◽  
Polydefkis Hatzopoulos ◽  
Yorgos Kotseridis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcoholic Fermentation ◽  
Ethanol Tolerance ◽  
Random Amplified Polymorphic Dna ◽  
Yeast Strains ◽  
Rapd Pcr ◽  
Autochthonous Yeast ◽  
Polymerase Chain ◽  
Grape Varieties ◽  
H2s Production

Nemea and Mantinia are famous wine regions in Greece known for two indigenous grape varieties, Agiorgitiko and Moschofilero, which produce high quality PDO wines. In the present study, indigenous Saccharomyces cerevisiae yeast strains were isolated and identified from spontaneous alcoholic fermentation of Agiorgitiko and Moschofilero musts in order to evaluate their oenological potential. Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) recovered the presence of five distinct profiles from a total of 430 yeast isolates. The five obtained strains were evaluated at microvinifications trials and tested for basic oenological and biochemical parameters including sulphur dioxide and ethanol tolerance as well as H2S production in sterile grape must. The selected autochthonous yeast strains named, Soi2 (Agiorgitiko wine) and L2M (Moschofilero wine), were evaluated also in industrial (4000L) fermentations to assess their sensorial and oenological characteristics. The volatile compounds of the produced wines were determined by GC-FID. Our results demonstrated the feasibility of using Soi2 and L2M strains in industrial fermentations for Agiorgitiko and Moschofilero grape musts, respectively.

scholarly journals Recombinant Diploid Saccharomyces cerevisiae Strain Development for Rapid Glucose and Xylose Co-Fermentation

Fermentation ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 59 ◽  
Author(s):  
Tingting Liu ◽  
Shuangcheng Huang ◽  
Anli Geng
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Xylose Isomerase ◽  
Cost Effective ◽  
Xylose Utilization ◽  
Yeast Strains ◽  
Multiple Copies ◽  
Biomass Sugars ◽  
Sugar Conversion

Cost-effective production of cellulosic ethanol requires robust microorganisms for rapid co-fermentation of glucose and xylose. This study aims to develop a recombinant diploid xylose-fermenting Saccharomyces cerevisiae strain for efficient conversion of lignocellulosic biomass sugars to ethanol. Episomal plasmids harboring codon-optimized Piromyces sp. E2 xylose isomerase (PirXylA) and Orpinomyces sp. ukk1 xylose (OrpXylA) genes were constructed and transformed into S. cerevisiae. The strain harboring plasmids with tandem PirXylA was favorable for xylose utilization when xylose was used as the sole carbon source, while the strain harboring plasmids with tandem OrpXylA was beneficial for glucose and xylose cofermentation. PirXylA and OrpXylA genes were also individually integrated into the genome of yeast strains in multiple copies. Such integration was beneficial for xylose alcoholic fermentation. The respiration-deficient strain carrying episomal or integrated OrpXylA genes exhibited the best performance for glucose and xylose co-fermentation. This was partly attributed to the high expression levels and activities of xylose isomerase. Mating a respiration-efficient strain carrying the integrated PirXylA gene with a respiration-deficient strain harboring integrated OrpXylA generated a diploid recombinant xylose-fermenting yeast strain STXQ with enhanced cell growth and xylose fermentation. Co-fermentation of 162 g L−1 glucose and 95 g L−1 xylose generated 120.6 g L−1 ethanol in 23 h, with sugar conversion higher than 99%, ethanol yield of 0.47 g g−1, and ethanol productivity of 5.26 g L−1·h−1.

scholarly journals Phenotypic and Genotypic Characterization of Uromyces appendiculatus from Phaseolus vulgaris in the Americas

Plant Disease ◽  
2004 ◽  
Vol 88 (8) ◽  
pp. 830-836 ◽  
Author(s):  
C. M. Araya ◽  
A. T. Alleyne ◽  
J. R. Steadman ◽  
K. M. Eskridge ◽  
D. P. Coyne
Keyword(s):  
Phaseolus Vulgaris ◽  
Central America ◽  
Random Amplified Polymorphic Dna ◽  
Parallel Evolution ◽  
Uromyces Appendiculatus ◽  
Bean Rust ◽  
Rapd Pcr ◽  
Polymerase Chain ◽  
Clear Differentiation

Populations of 90 Uromyces appendiculatus isolates were collected from throughout the Americas and evaluated for virulence on 19 standard bean rust differentials, and also on 12 landraces of Phaseolus vulgaris from South and Central America. The landrace differentials represented geographical centers of bean domestication. Three groups were observed. Two groups were isolates from centers of bean domestication and a third heterogeneous group comprised isolates from countries in South and Central America. Molecular analysis using random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was also conducted on these isolates. Cluster analysis of the molecular profiles showed three groups that corresponded to those obtained by virulence tests. These results show a clear differentiation of the pathogen population along similar lines as its host and suggest parallel evolution in the bean rust pathosystem.

scholarly journals Vacuolar H+-ATPase Protects Saccharomyces cerevisiae Cells against Ethanol-Induced Oxidative and Cell Wall Stresses

2016 ◽  
Vol 82 (10) ◽  
pp. 3121-3130 ◽  
Author(s):  
Sirikarn Charoenbhakdi ◽  
Thanittra Dokpikul ◽  
Thanawat Burphan ◽  
Todsapol Techo ◽  
Choowong Auesukaree
Keyword(s):  
Cell Wall ◽  
Alcoholic Fermentation ◽  
Ethanol Tolerance ◽  
Wall Stress ◽  
Yeast Cells ◽  
Intracellular Acidification ◽  
Straight Chain ◽  
Cell Wall Stress ◽  
Yeast Strains ◽  
Vacuolar Acidification

ABSTRACTDuring fermentation, increased ethanol concentration is a major stress for yeast cells. Vacuolar H+-ATPase (V-ATPase), which plays an important role in the maintenance of intracellular pH homeostasis through vacuolar acidification, has been shown to be required for tolerance to straight-chain alcohols, including ethanol. Since ethanol is known to increase membrane permeability to protons, which then promotes intracellular acidification, it is possible that the V-ATPase is required for recovery from alcohol-induced intracellular acidification. In this study, we show that the effects of straight-chain alcohols on membrane permeabilization and acidification of the cytosol and vacuole are strongly dependent on their lipophilicity. These findings suggest that the membrane-permeabilizing effect of straight-chain alcohols induces cytosolic and vacuolar acidification in a lipophilicity-dependent manner. Surprisingly, after ethanol challenge, the cytosolic pH in Δvma2and Δvma3mutants lacking V-ATPase activity was similar to that of the wild-type strain. It is therefore unlikely that the ethanol-sensitive phenotype ofvmamutants resulted from severe cytosolic acidification. Interestingly, thevmamutants exposed to ethanol exhibited a delay in cell wall remodeling and a significant increase in intracellular reactive oxygen species (ROS). These findings suggest a role for V-ATPase in the regulation of the cell wall stress response and the prevention of endogenous oxidative stress in response to ethanol.IMPORTANCEThe yeastSaccharomyces cerevisiaehas been widely used in the alcoholic fermentation industry. Among the environmental stresses that yeast cells encounter during the process of alcoholic fermentation, ethanol is a major stress factor that inhibits yeast growth and viability, eventually leading to fermentation arrest. This study provides evidence for the molecular mechanisms of ethanol tolerance, which is a desirable characteristic for yeast strains used in alcoholic fermentation. The results revealed that straight-chain alcohols induced cytosolic and vacuolar acidification through their membrane-permeabilizing effects. Contrary to expectations, a role for V-ATPase in the regulation of the cell wall stress response and the prevention of endogenous oxidative stress, but not in the maintenance of intracellular pH, seems to be important for protecting yeast cells against ethanol stress. These findings will expand our understanding of the mechanisms of ethanol tolerance and provide promising clues for the development of ethanol-tolerant yeast strains.

DNA FINGERPRINTING OF SINGLE APHID EMBRYOS BY RANDOM AMPLIFIED POLYMORPHIC DNA POLYMERASE CHAIN REACTION (RAPD–PCR)

1999 ◽  
Vol 131 (2) ◽  
pp. 229-230 ◽  
Author(s):  
C.K. Chan ◽  
D.J. Petersen ◽  
T.C. Vrain
Keyword(s):  
Polymerase Chain Reaction ◽  
Dna Polymerase ◽  
Acyrthosiphon Pisum ◽  
Random Amplified Polymorphic Dna ◽  
Aphis Gossypii ◽  
Aphis Fabae ◽  
Chain Reaction ◽  
Rapd Pcr ◽  
Laboratory Colonies ◽  
Polymerase Chain

Extraction of DNA from whole aphids, in combination with random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) (Williams et al. 1990) markers can detect interspecific and intraspecific genetic variation (Black et al. 1992; Cenis et al. 1993). However, these techniques entail destructive sampling of fresh or preserved specimens. To allow experimental replication from a single sample while preserving the same aphid for morphometrical or karyotyping analyses, we describe a technique for RAPD-PCR using DNA from single aphid embryos. We evaluated the usefulness and reliability of single-embryo analysis, using four species of our laboratory colonies, namely Acyrthosiphon pisum (Harris), Aphis fabae Scopoli, Aphis frangulae group, and Aphis gossypii Glover.

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