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1

Kinetic studies on the yeast Phaffia rhodozyma.  

PubMed

The yeast Phaffia rhodozyma, a promising microbial producer of the carotenoid astaxanthin, was cultivated in batch and continuous processes in an agitated and aerated fermenter using an acid peat extract based culture medium. For the accelerated growth phase, the mean specific growth rate and doubling time were found to be 0.038 h-1, and 18.24 hours, respectively. The production of astaxanthin was found to be basically growth associated, the maximum concentrations of the pigment produced in batch culture and continuous cultivation being similar. PMID:7608862

Acheampong, E A; Martin, A M

1995-01-01

2

Astaxanthin formation by the yeast Phaffia rhodozyma on molasses  

Microsoft Academic Search

Summary Phaffia rhodozyma grown on 7–10% B or C garde molasses contained 2 to 3 times more astaxanthin than reported earlier for this red yeast. Yield of astaxanthin with 10% molasses as fermentation substrate was 15.3 µg\\/ml which was about 3 times higher than with glucose and 2 times higher than with a sugar blend representative of the molasses.

N. F. Haard

1988-01-01

3

Biotechnological potential of Phaffia rhodozyma  

Microsoft Academic Search

Pigments, anthocyanin and carotenoids are natural compounds that are attractive in color and easy to extract. Astaxanthin is the principal carotenoid pigment responsible for the distinctive orange red pigmentation in marine invertebrates, fish, birds, salmonids and crustaceans. These animals obtain the pigment through their diet, which includes various astaxanthin producing microorganisms. Among such microorganisms Phaffia rhodozyma (red yeast), produces astaxanthin

Subhasita Roy; Sandipan Chatterjee; Sukanta Kumar

4

Separation of astaxanthin from red yeast Phaffia rhodozyma by supercritical carbon dioxide extraction  

Microsoft Academic Search

The supercritical fluid extraction (SFE) behavior was investigated to extract astaxanthin from the red yeast Phaffia rhodozyma, which was disrupted and dried by bead mill and spray dryer, respectively. The effects of extraction pressure (102–500bar), temperature (40, 60 and 80°C), CO2 flow rate (superficial velocities of 0.27 and 0.54cm\\/min) and the use of ethyl alcohol as a modifier (1, 5,

Gio-Bin Lim; Sang-Yun Lee; Eun-Kyu Lee; Seung-Joo Haam; Woo-Sik Kim

2002-01-01

5

Mixed culture of Bacillus circulans WL12 and Phaffia Rhodozyma on different carbon sources: Yeast-wall lytic enzyme production and extractability of astaxanthin  

Microsoft Academic Search

Summary Lytic enzyme production byBacillus circulans WL-12 and modification of the red yeastPhaffia rhodozyma in mixed culture, is feasible on some simple sugars other than glucose. Advantages of the mixed culture are discussed.

R. N. Okagbue; M. J. Lewis

1983-01-01

6

A factorial approach for a sugarcane juice-based low cost culture medium: increasing the astaxanthin production by the red yeast Phaffia rhodozyma  

Microsoft Academic Search

A sugarcane juice-based low cost culture medium was previously explored to produce the carotenoid pigment astaxanthin in liquid culture by the red yeast Phaffia rhodozyma (1300 7g astaxanthin\\/g of dry yeast and 6500 7g\\/l whole culture medium). Two peculiar limitations in Phaffia are growth temperature (7g\\/l) obtained was 23.0% but at the expense of 16.0% pigment content decrease (7g\\/g). In

J. A. Florêncio; C. R. Soccol; L. F. Furlanetto; T. M. B. Bonfim; N. Krieger; M. Baron; J. D. Fontana

1998-01-01

7

Effect of dietary astaxanthin rich yeast, Phaffia rhodozyma, on meat quality of broiler chickens.  

PubMed

We evaluated effects of dietary supplementation with astaxanthin (Ax)-rich yeast, Phaffia rhodozyma (Xanthophyllomyces dendrorhous), on broiler chicken meat quality. Fourteen-day-old female Ross broilers were divided into three groups: control group, Ax-free diet; Ax 10 group, 10?mg/kg Ax diet; and Ax 20 group, 20?mg/kg Ax diet for 28 days. At 42 days old, chickens were slaughtered, and then growth performance, meat quality and sensory attributes were analyzed. Compared with the control, a* values increased significantly after slaughter and 48?h postmortem for Ax 20 samples (P?yeast in the diet improves broiler chicken meat quality. PMID:24840792

Perenlei, Ganzaya; Tojo, Hitomi; Okada, Toru; Kubota, Masatoshi; Kadowaki, Motoni; Fujimura, Shinobu

2014-10-01

8

Autolysis of the red yeast Phaffia rhodozyma: A potential tool to facilitate extraction of astaxanthin  

Microsoft Academic Search

Distilled water and 0.02 molar citrate buffer pH 7.0, are suitable autolysing systems for the red yeast P. rhodozyma. Autolysis renders astaxanthin extractable from the yeast. Of six strains of the yeast tested, 67–484 was most susceptible to autolysis.

R. N. Okagbue; M. J. Lewis

1984-01-01

9

Favored isolation and rapid identification of the astaxanthin-producing yeast Xanthophyllomyces dendrorhous(Phaffia rhodozyma) from environmental samples.  

PubMed

Xanthophyllomyces dendrorhous (Phaffia rhodozyma) yeasts are biotechnologically exploited as a natural source of astaxanthin for aquaculture. Based on results of recent studies, it has become clear that this species possesses a greater genetic variability generating the necessity to uncover it and assess its potential for the astaxanthin industry. However, difficulties for the isolation of the X. dendrorhous hinder extensive environmental surveys which need to be carried out to better understand the habitat, distribution and genetic diversity of this species. We extensively searched for distinctive physiological traits of X. dendrorhours by testing phenotypic properties simultaneously with a panel of common sympatric fungi. As a result we obtained a new and innovative strategy for improving X. dendrorhous recovery rate and identification from environmental samples. This strategy involved the use of trehalose-based media, and a rapid X. dendrorhous identification method based on the simultaneous spectrophotometric detection of astaxanthin and UV-absorbing compounds (mycosporines). The proposed procedures proved effective in field trials conducted in natural environments of Patagonia (Argentina) and thus represent an important tool for the discovery of new astaxanthin-producing strains of X. dendrorhous useful for the aquaculture industry. PMID:23417292

Tognetti, Celia; Moliné, Martín; van Broock, María; Libkind, Diego

2013-09-01

10

Carotenoids protect Phaffia rhodozyma against singlet oxygen damage  

Microsoft Academic Search

Summary The only known habitat of the astaxanthin-containingPhaffia rhodozyma is in slime fluxes of deciduous trees at high altitudes. In this habitat, the function of carotenoids inP. rhodozyma is probably to provide protection against photogenerated antifungal substances in the tree flux such as singlet oxygen (1O2). To investigate the role of carotenoids inP. rhodozyma, genetic selections were employed to determine

William A. Schroeder; Eric A. Johnson

1995-01-01

11

Metabolic Engineering of the Carotenoid Biosynthetic Pathway in the Yeast Xanthophyllomyces dendrorhous (Phaffia rhodozyma)  

PubMed Central

The crtYB locus was used as an integrative platform for the construction of specific carotenoid biosynthetic mutants in the astaxanthin-producing yeast Xanthophyllomyces dendrorhous. The crtYB gene of X. dendrorhous, encoding a chimeric carotenoid biosynthetic enzyme, could be inactivated by both single and double crossover events, resulting in non-carotenoid-producing transformants. In addition, the crtYB gene, linked to either its homologous or a glyceraldehyde-3-phosphate dehydrogenase promoter, was overexpressed in the wild type and a ?-carotene-accumulating mutant of X. dendrorhous. In several transformants containing multiple copies of the crtYB gene, the total carotenoid content was higher than in the control strain. This increase was mainly due to an increase of the ?-carotene and echinone content, whereas the total content of astaxanthin was unaffected or even lower. Overexpression of the phytoene synthase-encoding gene (crtI) had a large impact on the ratio between mono- and bicyclic carotenoids. Furthermore, we showed that in metabolic engineered X. dendrorhous strains, the competition between the enzymes phytoene desaturase and lycopene cyclase for lycopene governs the metabolic flux either via ?-carotene to astaxanthin or via 3,4-didehydrolycopene to 3-hydroxy-3?-4?-didehydro-?-?-caroten-4-one (HDCO). The monocylic carotenoid torulene and HDCO, normally produced as minority carotenoids, were the main carotenoids produced in these strains. PMID:12839738

Verdoes, Jan C.; Sandmann, Gerhard; Visser, Hans; Diaz, Maria; van Mossel, Minca; van Ooyen, Albert J. J.

2003-01-01

12

Cultivation of the carotenoid-hyperproducing mutant 2A2N of the red yeast Xanthophyllomyces dendrorhous (Phaffia rhodozyma) with molasses.  

PubMed

The carotenoid-hyperproducing mutant 2A2N of the yeast Xanthophyllomyces dendrorhous (Phaffia rhodozyma) was cultivated using sugar beet blackstrap molasses. This molasses was composed of 70% (w/v) total solid and 50% (w/v) total sugar. Biomass yield (biomass/carbohydrate) significantly decreased at >5% (v/v) molasses. Atomic emission spectrometry revealed that Na and P were the limiting nutrients when molasses was used. Molasses (5%, v/v) containing urea (30 g/l molasses) and sodium phosphate (NaH2PO4, 5 g/l molasses) was formulated for biomass production by the mutant. The optimal pH for carotenoid production was 4.9 during the growth phase and 2.6-3.5 during the stationary phase. The three main sugars in molasses (sucrose, glucose, and fructose) were assimilated by the mutant but fructose was consumed slowly. When the formulated medium with pH 4.5-5.5 was used, the maximal biomass yield was 36 g/l (0.18 g of yeast l(-1)h(-1) and 40 mg of carotenoid l(-1)) in fed-batch pilot-scale 100-l cultivation. PMID:16233070

An, G H; Jang, B G; Cho, M H

2001-01-01

13

Optimization of acidic extraction of astaxanthin from Phaffia rhodozyma *  

PubMed Central

Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated, regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition: concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 °C, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 ?g/g and 1516.0 ?g/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice. PMID:18196613

Ni, Hui; Chen, Qi-he; He, Guo-qing; Wu, Guang-bin; Yang, Yuan-fan

2008-01-01

14

Genetic transformation of astaxanthin mutants of Phaffia rhodozyma  

Microsoft Academic Search

Stable red astaxanthin-producing transformants were obtained after genetic transformation of two Phaffia rhodozyma mutants. A yellow mutant, accumulating ß-carotene, and an albino mutant, accumulating phytoene, from P. rhodozyma were transformed using a genomic library of wild-type strain UCD 67-385 in the pBluescript vector. Hybridization assays, using the pBluescript DNA as a radioactive probe, indicate integration of vector sequences into the

C. Martínez; G. Hermosilla; R. León; G. Pincheira; V. Cifuentes

1998-01-01

15

Optimization of Culture Conditions for Production of Astaxanthin by Phaffia rhodozyma  

Microsoft Academic Search

The effect of medium components (carbon and nitrogen sources) and environmental factors (initial pH, temperature, and working volume) on biomass and astaxanthin production in Phaffia rhodozyma was investigated. The most suitable carbon, nitrogen, working volume, temperature, and initial pH for astaxanthin production were sucrose, yeast extract, 30ml\\/500ml, 20°C, and pH 7.0, respectively. Subsequently, the optimum incubation conditions (sucrose 40 g\\/l,

Xuewu Guo; Xianyu Li; Dongguang Xiao

2010-01-01

16

In situ carbon dioxide fixation in the process of natural astaxanthin production by a mixed culture of Haematococcus pluvialis and Phaffia rhodozyma  

Microsoft Academic Search

In order to fix CO2 generated by microbial fermentation, two astaxanthin over-producing microorganisms, the green alga Haematococcus pluvialis and the red yeast Phaffia rhodozyma, were mix-cultivated in the same media. CO2 from P. rhodozyma fermentation was fixed by H. pluvialis simultaneously in the process of photosynthesis, while O2 produced by H. pluvialis in photosynthesis stimulated astaxanthin formation in P. rhodozyma.

Qing-Lin Dong; Xue-Ming Zhao

2004-01-01

17

Optimization of acidic extraction of astaxanthin from Phaffia rhodozyma  

Microsoft Academic Search

Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated, regarding several extraction factors such as acids, organic solvents, temperature and\\u000a time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically\\u000a optimal model, which corresponded to the following optimal condition: concentration of lactic acid at 5.55 mol\\/L, ratio

Hui Ni; Qi-he Chen; Guo-qing He; Guang-bin Wu; Yuan-fan Yang

2008-01-01

18

Astaxanthin production by a Phaffia rhodozyma mutant on grape juice  

Microsoft Academic Search

During fermenter cultivation of Phaffia rhodozyma on a grape juice medium, the presence of glucose initially delayed fructose utilization, although fructose was consumed before glucose depletion. Total pigment and astaxanthin production were growth associated and reached maximum values of 15.9 µg\\/ml and 9.8 µg\\/ml, respectively, after depletion of the carbon source. The total cellular pigment and astaxanthin content increased during

P. S. Meyer; J. C. Preez

1994-01-01

19

Astaxanthin production by a Phaffia rhodozyma mutant on grape juice.  

PubMed

During fermenter cultivation of Phaffia rhodozyma on a grape juice medium, the presence of glucose initially delayed fructose utilization, although fructose was consumed before glucose depletion. Total pigment and astaxanthin production were growth associated and reached maximum values of 15.9 ?g/ml and 9.8 ?g/ml, respectively, after depletion of the carbon source. The total cellular pigment and astaxanthin content increased during the stationary growth phase due to a decrease in biomass, reaching final values of 2120 ?g/g and 1350 ?g/g, respectively, without the volumetric concentration in the culture changing. The final cell yield was 0.33 g/g sugar utilized. High sugar concentrations in shake-flasks as well as O2 limitation decreased the astaxanthin content of the cells. Addition of yeast extract to a grape juice minimal medium markedly increased the maximum specific growth rate, total pigment and astaxanthin content of the cells. An excess of ammonia decreased the intracellular astaxanthin content, which reached a maximal value in cultures with no residual glucose or ammonia. PMID:24420942

Meyer, P S; du Preez, J C

1994-03-01

20

Studies on optimization of nitrogen sources for astaxanthin production by Phaffia rhodozyma.  

PubMed

Fermentation of Phaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using (NH(4))(2)SO(4), KNO(3) and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L (NH(4))(2)SO(4), 0.49 g/L KNO(3) and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively. PMID:17542066

Ni, Hui; Chen, Qi-he; Ruan, Hui; Yang, Yuan-fan; Li, Li-jun; Wu, Guang-bin; Hu, Yang; He, Guo-qing

2007-05-01

21

Studies on optimization of nitrogen sources for astaxanthin production by Phaffia rhodozyma *  

PubMed Central

Fermentation of Phaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using (NH4)2SO4, KNO3 and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L (NH4)2SO4, 0.49 g/L KNO3 and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively. PMID:17542066

Ni, Hui; Chen, Qi-he; Ruan, Hui; Yang, Yuan-fan; Li, Li-jun; Wu, Guang-bin; Hu, Yang; He, Guo-qing

2007-01-01

22

ASTAXANTHIN PRODUCTION BY PHAFFIA RHODOZYMA IN A FED BATCH CULTURE USING A LOW COST MEDIUM FEEDING PRODUCCIÓN DE ASTAXANTINA POR PHAFFIA RHODOZYMA EN UN CULTIVO POR LOTE ALIMENTADO UTILIZANDO UN MEDIO DE CULTIVO DE BAJO COSTO  

Microsoft Academic Search

The mutant strain 25-2 of Phaffia rhodozyma was grown in Yucca medium using a fed-batch culture system. The feeding control in the culture medium was carried out in response to pH changes (acid to alkaline) caused by the metabolic activity of the yeasts. This change was understood as a signal of low nutrients of the culture and, therefore, as the

Jesús Ramírez; Noemí Obledo; Melchor Arellano; Enrique Herrera

23

[Characterization and evaluation of an astaxanthin over-producing Phaffia rhodozyma].  

PubMed

We evaluated an astaxanthin overproducing Phaffia rhodozyma JMU-MVP14, and developed astaxanthin high-yielding fermentation process. We analyzed several fermentation parameters, i.e., biomass, astaxanthin and total carotenoids content to compare the characteristics of P rhodozyma JMU-MVP14 and the original strain through flask fermentation experiments. We conducted batch and fed-batch fermentation experiments in 7 L fermentor to investigate the effects of pH controlling models and feeding medium compositions on the production of astaxanthin. We further evaluated the capability and practical value of P rhodozyma JMU-MVP14 by fed-batch cultivation in the 1 m3 fermentor. Flask fermentation experiments revealed that P. rhodozyma JMU-MVP14 produced high yield of astaxanthin and carotenoids with specific productivity of astaxanthin and specific productivity of total carotenoids of 6.01 mg/g and 10.38 mg/g. Results of batch culture experiments in the 7 L fermentor showed that controlling the pH by ammonia auto-feeding was better than discontinuously adjusting pH value at 6.0 with regard to the high productivities of biomasses and astaxanthin. This P. rhodozyma strain synthesized astaxanthin partially linked to the growth with the Ks and pmax of 0.20 h ' and 21.73 g/L, respectively. Results of batch-fed fermentations in 7 L fermentor indicated that the complex feeding medium consisted of 50% glucose, 0.5% yeast extract and 0.3% corn steep syrup had lower astaxanthin productivity than the simple feeding medium containing only 50% glucose, which produced biomass, volumetric productivity of astaxanthin, volumetric productivity of total carotenoids, specific productivity of astaxanthin and total carotenoids at 32.81 g/L, 155.99 mg/L, 4.94 mg/g, 399.99 mg/L and 12.19 mg/g, respectively. As fed-batch cultured in 1 m3 fermentor, P rhodozyma JMU-MVP14 yielded 85.11 g/L of biomass, 279.96 mg/L of volumetric productivity of astaxanthin, 618.01 mg/L of volumetric productivity of total carotenoids, 3.29 mg/g of specific productivity of astaxanthin and 7.26 mg/g of specific productivity of total carotenoids. Additionally, P rhodozyma JMU-MVP14 cell contained 21.54% of protein, 41.34% of carbohydrate and 34.31% of lipid. These comprehensive results suggest that P. rhodozyma JMU-MVPl14 has great practical prosperity related to its strong ability to produce astaxanthin and good value byproducts. PMID:22016991

Ni, Hui; Hong, Qinglin; Xiao, Anfeng; Li, Lijun; Cai, Huinong; Su, Wenjin

2011-07-01

24

An improved process for cell disruption and astaxanthin extraction from Phaffia rhodozyma  

Microsoft Academic Search

Phaffia rhodozyma is one of the most important natural sources of the carotenoid astaxanthin, and the key process for extracting intracellular\\u000a astaxanthin is disrption of the thick cell wall. In this work, an improved process for cell disruption and astaxanthin extraction\\u000a from Phaffica rhodozyma was studied using an autoclave at low acid concentration. Under the optimum conditions (HCl 0.5 M and

An-Feng Xiao; Hui Ni; Hui-Nong Cai; Li-Jun Li; Wen-Jin Su; Qiu-Ming Yang

2009-01-01

25

Growth and carotenoid production by pH-stat cultures of Phaffia rhodozyma  

Microsoft Academic Search

To optimize biomass and carotenoid production by Phaffia rhodozyma in pH-stat cultures, two methods of feeding glucose were studied. In the first method, which is comparatively simple to operate, the glucose feeding set point (pH 5.02) was higher than the culture pH (5.00) and P. rhodozyma grew at a low specific growth rate (µ=0.055 h-1). In the second method, the glucose feeding set point

H. Y. Chan; K. P. Ho

1999-01-01

26

Application of derivative ratio spectrophotometry for determination of ?-carotene and astaxanthin from Phaffia rhodozyma extract  

Microsoft Academic Search

A derivative ratio spectrophotometric method was used for the simultaneous determination of ?-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490 nm demonstrated that their absorptive spectra accorded with Beer's law and that the additivity when the concentrations of ?-carotene and astaxanthin and their mixture were

NI Hui; RUAN Hui; CHEN Qi-he; CHEN Feng

27

Optimization of astaxanthin production by Phaffia rhodozyma through factorial design and response surface methodology  

Microsoft Academic Search

Sequential methodology based on the application of three types of experimental designs was used to optimize the astaxanthin production of the mutant strain 25-2 of Phaffia rhodozyma in shake flask cultures. The first design employed was a factorial design 25, where the factors studied were: pH, temperature, percent of inoculum, carbon and nitrogen concentrations, each one at two levels. This

Jesús Ram??rez; Humberto Gutierrez; Anne Gschaedler

2001-01-01

28

Citrate, a possible precursor of astaxanthin in Phaffia rhodozyma : influence of varying levels of ammonium, phosphate and citrate in a chemically defined medium  

Microsoft Academic Search

The influence of ammonium, phosphate and citrate on astaxanthin production by the yeast Phaffia rhodozyma was investigated. The astaxanthin content in cells and the final astaxanthin concentration increased upon reduction of ammonium from 61 mM to 12.9 mM (from 140 µg\\/g to 230 µg\\/g and 1.2 µg\\/ml to 2.3 µg\\/ml, respectively). Similarly, both the astaxanthin content and astaxanthin concentration increased

L. B. Flores-Cotera; R. Martín; S. Sánchez

2001-01-01

29

Astaxanthin production by Phaffia rhodozyma and Haematococcus pluvialis : a comparative study  

Microsoft Academic Search

Phaffia rhodozyma (now Xanthophyllomyces dendrorhous) and Haematococcus pluvialis are known as the major prominent microorganisms able to synthesize astaxanthin natural pigment. Important research efforts\\u000a have been made to determine optimal conditions for astaxanthin synthesis. When the focus is on astaxanthin production, the\\u000a maximal reported value of 9.2 mg\\/g cell is obtained within H. pluvialis grown on BAR medium, under continuous illumination

A. R. Domínguez-Bocanegra; T. Ponce-Noyola; J. A. Torres-Muñoz

2007-01-01

30

Selection and evaluation of astaxanthin-overproducing mutants of Phaffia rhodozyma  

Microsoft Academic Search

Mutagenesis of Phaffia rhodozyma with NTG yielded a mutant with an astaxanthin content of 1688 µg (g dry biomass)-1, a cell yield coefficient of 0.47 on glucose and a maximum specific growth rate of 0.12 h-1. Re-mutation of the mutant decreased the cell yield and maximum specific growth rate but increased the astaxanthin content. The use of mannitol or succinate

P. S. Meyer; J. C. Preez; S. G. Kilian

1993-01-01

31

Effect of Phaffia rhodozyma on performance, nutrient digestibility, blood characteristics, and meat quality in finishing pigs.  

PubMed

The red yeast, Phaffia rhodozyma (PR), has possible applications as a component of diets for use in the animal industry. Its primary value lies in its content of astaxanthin, which has been shown to be an antioxidant several times more effective than vitamin E. A total of 96 ([Landrace × Yorkshire] × Duroc) crossbred pigs with an initial BW of 58.61 ± 3.05 kg were used in this 10-wk feeding study to determine the effects of PR on growth performance, nutrient digestibility, blood characteristics, and meat quality in finishing pigs. Pigs were randomly allotted to 1 of 3 corn-soybean meal-based diets supplemented with 0, 0.1, or 0.2% PR. There were 8 replicate pens per treatment with 4 pigs (2 barrows and 2 gilts) per pen. The inclusion of PR linearly improved G:F in the phase 1 (P = 0.02), phase 2 (P = 0.02), and during the overall experimental period (P < 0.01) The DM digestibility was improved in the 0.1% PR treatment in phase 2 (quadratic, P = 0.01). The white blood cell concentration was increased in 0.1% PR group (P < 0.05) during phase 2 (quadratic, P < 0.01) and phase 2 (P = 0.04). The inclusion of graded levels of PR linearly increased (P < 0.01) the pH of LM. The 2-thiobarbituric acid reactive substances were linearly decreased (P = 0.03) by the supplementation of PR. In conclusion, the inclusion of PR could improve feed efficiency, DM digestibility, and meat quality of the finishing pig. PMID:24352965

Lei, Y; Kim, I H

2014-01-01

32

Antiproliferation and induction of cell death of Phaffia rhodozyma (Xanthophyllomyces dendrorhous) extract fermented by brewer malt waste on breast cancer cells.  

PubMed

Astaxanthin has been shown to have antiproliferative activity on breast cancer and skin cancer cells. However, the high cost of production, isolation and purification of purified astaxanthin from natural sources or chemically synthetic methods limit its usage on cancer therapy. We show that astaxanthin could be produced by fermentating the Phaffia rhodozyma (Xanthophyllomyces dendrorhous) yeast cells with brewer malt waste using a 20 L B. Braun fermentor. The percentage composition of astaxanthin from the P. rhodozyma was >70% of total pigment as estimated by the high performance liquid chromatographic analysis. Furthermore, the antiproliferative activity of this P. rhodozyma cell extract (PRE) was demonstrated on breast cancer cell lines including the MCF-7 (estrogen receptor positive) and MDA-MB231 (estrogen receptor negative) by using the [3-(4,5-dimethylthiazol-2-yl)-5-(3-arboxymethoxyphenyl)-2- (4-sulfophenyl)-2H-tetrazolium] (MTS) assay. No apoptotic cell death, but growth inhibitory effect was induced after 48 h of PRE incubation as suggested by morphological investigation. Anchorage-dependent clonogenicity assay showed that PRE could reduce the colony formation potential of both breast cancer cell lines. Cell death was observed from both breast cancer cell lines after incubation with PRE for 6 days. Taken together, our results showed that by using an economic method of brewer malt waste fermentation, we obtained P. rhodozyma with a high yield of astaxanthin and the corresponding PRE could have short-term growth inhibition and long-term cell death activity on breast cancer cells. PMID:16211266

Teo, Ivy Tuang Ngo; Chui, Chung Hin; Tang, Johnny Cheuk On; Lau, Fung Yi; Cheng, Gregory Yin Ming; Wong, Raymond Siu Ming; Kok, Stanton Hon Lung; Cheng, Chor Hing; Chan, Albert Sun Chi; Ho, Kwok Ping

2005-11-01

33

Application of derivative ratio spectrophotometry for determination of ?-carotene and astaxanthin from Phaffia rhodozyma extract*  

PubMed Central

A derivative ratio spectrophotometric method was used for the simultaneous determination of ?-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490 nm demonstrated that their absorptive spectra accorded with Beer’s law and that the additivity when the concentrations of ?-carotene and astaxanthin and their mixture were within the range of 0 to 5 µg/ml, 0 to 6 µg/ml, and 0 to 6 µg/ml, respectively. When the wavelength interval (??) at 2 nm was selected to calculate the first derivative ratio spectra values, the first derivative amplitudes at 461 nm and 466 nm were suitable for quantitatively determining ?-carotene and astaxanthin, respectively. Effect of divisor on derivative ratio spectra could be neglected; any concentration used as divisor in range of 1.0 to 4.0 µg/ml is ideal for calculating the derivative ratio spectra values of the two carotenoids. Calibration graphs were established for ?-carotene within 0–6.0 µg/ml and for astaxanthin within 0–5.0 µg/ml with their corresponding regressive equations in: y=?0.0082x?0.0002 and y=0.0146x?0.0006, respectively. R-square values in excess of 0.999 indicated the good linearity of the calibration graphs. Sample recovery rates were found satisfactory (>99%) with relative standard deviations (RSD) of less than 5%. This method was successfully applied to simultaneous determination of ?-carotene and astaxanthin in the laboratory-prepared mixtures and the extract from the Phaffia rhodozyma culture. PMID:15909336

Ni, Hui; He, Guo-qing; Ruan, Hui; Chen, Qi-he; Chen, Feng

2005-01-01

34

Effect of culture conditions on astaxanthin production by a mutant of Phaffia rhodozyma in batch and chemostat culture  

Microsoft Academic Search

Temperature and pH had only a slight effect on the astaxanthin content of a Phaffia rhodozyma mutant, but influenced the maximum specific growth rate and cell yield profoundly. The optimum conditions for astaxanthin production were 22°C at pH 5.0 with a low concentration of carbon source. Astaxanthin production was growth-associated, and the volumetric astaxanthin concentration gradually decreased after depletion of

Petrus S. Meyer; James C. Du Preez

1994-01-01

35

Extraction and quantitation of astaxanthin from Phaffia rhodozyma  

Microsoft Academic Search

The rapid, quantitative release of astaxanthin and other carotenoids from the yeast Phaffiarhodozyma is described. Hashed cells are ruptured with dimethylsulfoxide (DMSO) and carotenoids extracted into an organic solvent. Extraction and spectrophotometric quantitation of total carotenoids is rapid, reproducible and only small volumes (0.1–2 ml) of culture are required. HPLC analysis in normal phase silica gel column indicates that astaxanthin

J. James Sedmak; Deepthi K. Weerasinghe; Setsuko O. Jolly

1990-01-01

36

Genotoxicity and subacute toxicity studies of a new astaxanthin-containing Phaffia rhodozyma extract.  

PubMed

Experimental and clinical studies demonstrate that astaxanthin (AXN), a xanthophyll carotenoid, has protective effects against oxidative damage. Because most of these studies assessed AXN derived from Haematococcus pluvialis that were cultivated at industrial scales, few studies have examined the toxicity of AXN derived from Phaffia rhodozyma. To evaluate the safety of astaxanthin-containing P. rhodozymaextract (AXN-PRE), genotoxicity was assessed in bacterial reverse mutation test and mouse bone marrow micronucleus test, and general toxicity was assessed in 4-week repeated oral toxicity study in rats. AXN-PRE did not induce reverse mutations in the Salmonella typhimurium strains TA98 or TA100 at concentrations of 5,000 µg/plate with or without S9 mix, and no chromosome damage was observed at a dose of 2,000 mg/kg in mouse micronucleus test. In the subacute toxicity study, male and female Sprague-Dawley rats were given AXN-PRE at doses of 0, 500, and 1,000 mg/kg by gavage for 4 weeks. Body weights, urinalysis, hematology, serum biochemistry, organ weights, or histopathological lesions indicated no distinct toxicity. In conclusion, AXN-PRE had no effect in bacterial reverse mutation test and mouse bone marrow micronucleus test. The no-observed-adverse-effect level for AXN-PRE in 4-week repeated oral toxicity study in rats was determined to be greater than 1,000 mg/kg (corresponding to dose of 50 mg/kg AXN) regardless of gender. PMID:24849672

Tago, Yoshiyuki; Fujii, Toshihide; Wada, Jutaro; Kato, Masanori; Wei, Min; Wanibuchi, Hideki; Kitano, Mitsuaki

2014-06-01

37

Isolation of astaxanthin over-producing mutants of Phaffia rhodozyma and their fermentation kinetics.  

PubMed

Phaffia rodozyma CCRC-21346, CBS-6938, and CBS-5908 were treated with mutagenic agent NTG (N-methyl-N'-nitro-N-nitrosoguanidine) several times, then they were plated onto yeast-malt agar containing beta-ionone as a selective medium. Several isolates had increased astaxanthin content compared with the parental natural isolates. NCHU-FS301, one of the NTG treated strains, produced considerably more astaxanthin (1515.63 micrograms/g yeast) than the parent CBS-6938 (565.08 micrograms/g yeast). In studying the effects of carbon sources on the red pigment formation, it was found that glucose supported the highest total astaxanthin production (7809.3 micrograms/l). Yeast extract was the best nitrogen source in supporting the highest total astaxanthin formation (8637.5 micrograms/l). Beef extract, yeast extract, and potassium nitrate added in an equal ratio as a nitrogen source supported more pigment formation (8052.6 micrograms/l) than the rest of the mixture tested. Using kinetic parameters of specific growth rate (mu) and specific astaxanthin productivity (qp) to judge the association between growth behavior and product formation, the NCHU-FS301 showed more positive growth-associated fermentation type than the parent strain. These astaxanthin-overproducing mutants could be useful for the aquacultural industry in providing a natural source of astaxanthin. PMID:1342638

Fang, T J; Cheng, Y S

1992-11-01

38

Application of derivative ratio spectrophotometry for determination of beta-carotene and astaxanthin from Phaffia rhodozyma extract.  

PubMed

A derivative ratio spectrophotometric method was used for the simultaneous determination of beta-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490 nm demonstrated that their absorptive spectra accorded with Beer's law and that the additivity when the concentrations of beta-carotene and astaxanthin and their mixture were within the range of 0 to 5 microg/ml, 0 to 6 microg/ml, and 0 to 6 microg/ml, respectively. When the wavelength interval (lambda) at 2 nm was selected to calculate the first derivative ratio spectra values, the first derivative amplitudes at 461 nm and 466 nm were suitable for quantitatively determining beta-carotene and astaxanthin, respectively. Effect of divisor on derivative ratio spectra could be neglected; any concentration used as divisor in range of 1.0 to 4.0 microg/ml is ideal for calculating the derivative ratio spectra values of the two carotenoids. Calibration graphs were established for beta-carotene within 0-6.0 microg/ml and for astaxanthin within 0-5.0 microg/ml with their corresponding regressive equations in: y=-0.0082x-0.0002 and y=0.0146x-0.0006, respectively. R-square values in excess of 0.999 indicated the good linearity of the calibration graphs. Sample recovery rates were found satisfactory (>99%) with relative standard deviations (RSD) of less than 5%. This method was successfully applied to simultaneous determination of beta-carotene and astaxanthin in the laboratory-prepared mixtures and the extract from the Phaffia rhodozyma culture. PMID:15909336

Ni, Hui; He, Guo-qing; Ruan, Hui; Chen, Qi-he; Chen, Feng

2005-06-01

39

Analysis of proteomic changes in colored mutants of Xanthophyllomyces dendrorhous (Phaffia rhodozyma).  

PubMed

The yeast Xanthophyllomyces dendrorhous synthesizes astaxanthin as its most prevalent xanthophyll derivative. Comparisons between the protein profiles of mutant lines of this yeast can provide insight into the carotenogenic pathway. Differently colored mutants (red, orange, pink, yellow, and white) were obtained from this yeast species, and their protein profiles were determined using two-dimensional polyacrylamide gel electrophoresis (2DE). Individual proteins differentially expressed were identified using mass spectrometry. The red mutants hyperproduced total carotenoids (mainly astaxanthin), while in white and orange mutants, mutagenesis affected the phytoene dehydrogenase activity as indicated by the accumulation of phytoene. Inactivation of astaxanthin synthase after the mutagenic treatment was evident in ?-carotene accumulating mutants. Differences in the proteomic profiles of wild-type X. dendrorhous and its colored mutants were demonstrated using 2DE. Of the total number of spots detected in each gel (297-417), 128 proteins were present in all strains. The red mutant showed the greatest number of matches with respect to the wild type (305 spots), while the white and yellow mutants, which had reduced concentrations of total carotenoids, presented the highest correlation coefficient (0.6) between each other. A number of differentially expressed proteins were sequenced, indicating that tricarboxylic acid cycle and stress response proteins are closely related to the carotenogenic process. PMID:24676883

Barbachano-Torres, Alejandra; Castelblanco-Matiz, Lina M; Ramos-Valdivia, Ana C; Cerda-García-Rojas, Carlos M; Salgado, Luis M; Flores-Ortiz, César M; Ponce-Noyola, Teresa

2014-06-01

40

Stability of astaxanthin from red yeast, Xanthophyllomyces dendrorhous, during feed processing: effects of enzymatic cell wall disruption and extrusion temperature  

Microsoft Academic Search

The effect of different degrees of enzymatic cell wall disruption (45%, 70%, and 97%) of red yeast (Xanthophyllomyces dendrorhous, formerly Phaffia rhodozyma) and extruder temperatures (102, 121, and 137 °C) on astaxanthin stability and formation of astaxanthin Z-isomers was determined during extruded fish feed production. Enzymatic cell wall disruption was expressed as acetone extractable carotenoids in percent of total amount

Trond Storebakken; Mette Sørensen; Bjørn Bjerkeng; John Harris; Patrick Monahan; Stephen Hiu

2004-01-01

41

Stimulation of astaxanthin formation in the yeast Xanthophyllomyces dendrorhous by the fungus Epicoccum nigrum.  

PubMed

A fungal contaminant on an agar plate containing colonies of Xanthophyllomyces dendrorhous markedly increased carotenoid production by yeast colonies near to the fungal growth. Spent-culture filtrate from growth of the fungus in yeast-malt medium also stimulated carotenoid production by X. dendrorhous. Four X. dendrorhous strains including the wild-type UCD 67-385 (ATCC 24230), AF-1 (albino mutant, ATCC 96816), Yan-1 (beta-carotene mutant, ATCC 96815) and CAX (astaxanthin overproducer mutant) exposed to fungal concentrate extract enhanced astaxanthin up to approximately 40% per unit dry cell weight in the wild-type strain and in CAX. Interestingly, the fungal extract restored astaxanthin biosynthesis in non-astaxanthin-producing mutants previously isolated in our laboratory, including the albino and the beta-carotene mutant. The fungus was identified as Epicoccum nigrum by morphology of sporulating cultures, and the identity confirmed by genetic characterization including rDNA sequencing analysis of the large-subunit (LSU), the internal transcribed spacer, and the D1/D2 region of the LSU. These E. nigrum rDNA sequences were deposited in GenBank under accesssion numbers AF338443, AY093413 and AY093414. Systematic rDNA homology alignments were performed to identify fungi related to E. nigrum. Stimulation of carotenogenesis by E. nigrum and potentially other fungi could provide a novel method to enhance astaxanthin formation in industrial fermentations of X. dendrorhous and Phaffia rhodozyma. PMID:14734032

Echavarri-Erasun, Carlos; Johnson, Eric A

2004-01-01

42

Muscle Pigmentation of Rainbow Trout (Oncorhynchus mykiss) Fed on Oil-Extracted Pigment from Langostilla (Pleuroncodes planipes) Compared with Two Commercial Sources of Astaxanthin  

Microsoft Academic Search

A comparative study of flesh pigmentation efficiency of oil-extracted astaxanthin from langostilla (Pleumncodes planipes) a red yeast (Phaffia rhodozyma) and synthetic astaxanthin (Caro-phyll pink) on rainbow trout (Oncorhynchus mykiss) was conducted. Fish (218 ± 7 g) were allocated into three experimental groups (fed diets with 75 mg of carotenoid per kg of feed) and one control group. Weights, flesh carotenoid

Gladis Coral; Alberto Huberman; Guadalupew de la Lanza; Jose Monroy-Ruiz

1998-01-01

43

Cloning of the astaxanthin synthase gene from Xanthophyllomyces dendrorhous ( Phaffia rhodozyma ) and its assignment as a ?-carotene 3-hydroxylase\\/4ketolase  

Microsoft Academic Search

A gene has been cloned from Xanthophyllomyces dendrorhous by complementation of astaxanthin formation in a ?-carotene accumulating mutant. It consists of 3,166 bp and contains 17\\u000a introns. For the ?-carotene mutant ATCC 96815, a single point mutation in the splicing sequence of intron 8 was found. The\\u000a resulting improper splicing of the mRNA results in an inactive protein. The cDNA of

Kazuyuki Ojima; Jürgen Breitenbach; Hans Visser; Yutaka Setoguchi; Kazuyuki Tabata; Tatsuo Hoshino; Johan van den Berg; Gerhard Sandmann

2006-01-01

44

Production and optimization of carotenoid-enriched dried distiller’s grains with solubles by Phaffia rhodozyma and Sporobolomyces roseus fermentation of whole stillage  

Microsoft Academic Search

Whole stillage—a co-product of grain-based ethanol—is used as an animal feed in the form of dried distiller’s grain with solubles\\u000a (DDGS). Since animals cannot synthesize carotenoids and animal feed is generally poor in carotenoids, about 30–120 ppm of\\u000a total carotenoids are added to animal feed to improve animal health, enhance meat color and quality, and increase vitamin\\u000a A levels in milk

Nanjundaswamy Ananda; Praveen V. Vadlani

2010-01-01

45

Extractability of astaxanthin in a mixed culture of a carotenoid over-producing mutant of Xanthophyllomyces dendrorhous and Bacillus circulans in two-stage batch fermentation  

Microsoft Academic Search

The productivity and extractability of astaxanthin in a mixed culture of Xanthophyllomyces dendrorhous (formerly Phaffia rhodozyma) NCHU-FS501, an astaxanthin over-producing mutant, and Bacillus circulans CCRC 11590 was evaluated in a 1.5 l fermentor using a two-stage batch fermentation technique. The first stage was for X. dendrorhous cultivation. The second stage was the mixed fermentation of the red yeast and B.

Tony J. Fang; Joh-Ming Wang

2002-01-01

46

Yeast Infections  

MedlinePLUS

Candida is the scientific name for yeast. It is a fungus that lives almost everywhere, including in ... infection that causes white patches in your mouth Candida esophagitis is thrush that spreads to your esophagus, ...

47

Yeast 14, 14531469 (1998) Expanding Yeast Knowledge Online  

E-print Network

YEAST Yeast 14, 1453­1469 (1998) Expanding Yeast Knowledge Online KARA DOLINSKI1 , CATHERINE A in the amount of new yeast genetics and molecular biology data. Efficient organization, presentation Sequences; Yeast Protein Database CONTENTS Introduction

Botstein, David

48

Multiple improvement of astaxanthin biosynthesis in Xanthophyllomyces dendrorhous by a combination of conventional mutagenesis and metabolic pathway engineering.  

PubMed

Xanthophyllomyces dendrorhous (Phaffia rhodozyma) is the only yeast or fungus that synthesizes the commercially attractive carotenoid astaxanthin. For a suitable bioprocess, the wild type has to be modified for increasing biomass content. To achieve this, a two step strategy has been followed. At first, random mutagenesis was applied leading to colonies with substantially higher astaxanthin content. Then, the resulting strain was genetically engineered by targeting limiting reactions for further enhancement of astaxanthin biosynthesis. This combinatorial approach together with selection of an appropriate growth medium resulted in highest astaxanthin biomass contents reported to date for X. dendrorhous. In a fermenter culture, its maximum content was 9.7 mg/g dry weight. PMID:23187756

Gassel, Sören; Schewe, Hendrik; Schmidt, Isabell; Schrader, Jens; Sandmann, Gerhard

2013-04-01

49

Protein expression-yeast.  

PubMed

Yeast is an excellent system for the expression of recombinant eukaryotic proteins. Both endogenous and heterologous proteins can be overexpressed in yeast (Phan et al., 2001; Ton and Rao, 2004). Because yeast is easy to manipulate genetically, a strain can be optimized for the expression of a specific protein. Many eukaryotic proteins contain posttranslational modifications that can be performed in yeast but not in bacterial expression systems. In comparison with mammalian cell culture expression systems, growing yeast is both faster and less expensive, and large-scale cultures can be performed using fermentation. While several different yeast expression systems exist, this chapter focuses on the budding yeast Saccharomyces cerevisiae and will briefly describe some options to consider when selecting vectors and tags to be used for protein expression. Throughout this chapter, the expression and purification of yeast eIF3 is shown as an example alongside a general scheme outline. PMID:24423273

Nielsen, Klaus H

2014-01-01

50

Yeast Based Sensors  

NASA Astrophysics Data System (ADS)

Since the first microbial cell sensor was studied by Karube et al. in 1977, many types of yeast based sensors have been developed as analytical tools. Yeasts are known as facultative anaerobes. Facultative anaerobes can survive in both aerobic and anaerobic conditions. The yeast based sensor consisted of a DO electrode and an immobilized omnivorous yeast. In yeast based sensor development, many kinds of yeast have been employed by applying their characteristics to adapt to the analyte. For example, Trichosporon cutaneum was used to estimate organic pollution in industrial wastewater. Yeast based sensors are suitable for online control of biochemical processes and for environmental monitoring. In this review, principles and applications of yeast based sensors are summarized.

Shimomura-Shimizu, Mifumi; Karube, Isao

51

CLONTECHInnovative Yeast Protocols Handbook  

E-print Network

CLONTECHInnovative Tools to Accelerate Discovery Yeast Protocols Handbook PT3024-1 (PR13103 FOR RESEARCH USE ONLY #12;Yeast Protocols Handbook CLONTECH Laboratories, Inc. www.clontech.com Protocol # PT3024-1 2 Version # PR13103 I. Introduction 4 II. Introduction to Yeast Promoters 5 III. Culturing

Erickson, F. Les

52

[Yeasts contaminating salmon roe].  

PubMed

Quantitative and species compositions of yeast contaminating eggs, fry and fingerlings of Salmo gairdneri Rich under artificial breeding have been studied. Prevalence of species of genera Candida, Rhodotorula, Cryptococcus and Debaryomyces is noted. Yeast isolated from perished eggs and sick fry do not possess pathogenic properties. Certain strains of yeast make stimulating effect on the studied microorganisms. PMID:8983527

Nagornaia, S S; Ignatova, E A; Isaeva, N M; Davydov, O N; Podgorski?, V S

1996-01-01

53

YEAST GENETICS Fred Winston  

E-print Network

YEAST GENETICS Fred Winston 7.1 Introduction Key Concepts · Genetic studies of the yeast. The yeast Saccharomyces cerevisiae is an ideal experimental organism. It is a microorganism that has a fast rate of growth, with a generation time of only ninety minutes under optimal conditions. Genetic methods

Winston, Fred

54

Extraction of lipids from fermentation biomass using near-critical dimethylether  

Microsoft Academic Search

The extraction of lipids from both wet and dry biomass produced by fermentation has been carried out using near-critical dimethylether (DME) as the extraction solvent. Fermentations were carried out from a shake flask up to a 300L scale using the microorganism Mortierella alpina, and up to a 20L scale for Phaffia rhodozyma and Agrobacterium tumefaciens. The lipids extracted at a

Owen Catchpole; Jason Ryan; Yin Zhu; Kristina Fenton; John Grey; Mikhail Vyssotski; Andrew MacKenzie; Eduard Nekrasov; Kevin Mitchell

2010-01-01

55

Mitochondrial assembly in yeast  

Microsoft Academic Search

The yeast Saccharomyces cerevisiae is likely to be the first organism for which a complete inventory of mitochondrial proteins and their functions can be drawn up. A survey of the 340 or so proteins currently known to be localised in yeast mitochondria reveals the considerable investment required to maintain the organelle’s own genetic system, which itself contributes seven key components

Les A Grivell; Marta Artal-Sanz; Gertjan Hakkaart; Liesbeth de Jong; Leo G. J Nijtmans; Katinka van Oosterum; Michel Siep; Hans van der Spek

1999-01-01

56

Yeasts: Neglected Pathogens  

Microsoft Academic Search

Background: Current research on Crohn’s disease (CD) concerns molecular events related to loss of tolerance to microbes that could trigger or maintain inflammation in genetically susceptible individuals. CD is also associated with antimicrobial antibodies, including the antibodies we described against yeast oligomannosides (ASCA). This prompted us to investigate a role for another yeast, Candida albicans, a very common commensal of

Daniel Poulain; Boualem Sendid; Annie Standaert-Vitse; Chantal Fradin; Thierry Jouault; Samir Jawhara; Jean-Frederic Colombel

2009-01-01

57

Prions in Yeast  

PubMed Central

The concept of a prion as an infectious self-propagating protein isoform was initially proposed to explain certain mammalian diseases. It is now clear that yeast also has heritable elements transmitted via protein. Indeed, the “protein only” model of prion transmission was first proven using a yeast prion. Typically, known prions are ordered cross-? aggregates (amyloids). Recently, there has been an explosion in the number of recognized prions in yeast. Yeast continues to lead the way in understanding cellular control of prion propagation, prion structure, mechanisms of de novo prion formation, specificity of prion transmission, and the biological roles of prions. This review summarizes what has been learned from yeast prions. PMID:22879407

Liebman, Susan W.; Chernoff, Yury O.

2012-01-01

58

Yeast Proteome Analysis  

NASA Astrophysics Data System (ADS)

Yeast organisms, and specifically Saccharomyces cerevisiae, have become model systems for many aspects in fundamental and applied research. Consistently, many papers have been published applying proteome techniques to study these organisms. The review will give an overview on the proteome research performed on yeast systems so far; however, due to the large number of publications, only selected reports can be cited neglecting many more interesting ones in the interest of space. The review will focus on research involving mass spectrom-etry as a basic proteome technique, although many more approaches are relevant for the functional characterization of proteins in the cell, e.g. the yeast two-hybrid system. We will provide an overview on yeasts as models in the context of pro-teome analysis, and explain the basic techniques currently applied in proteome approaches. The main part of the review will deal with a survey on the current status of proteomic studies in yeasts. In a first part of this chapter, we will deal with the currently available proteome maps of yeasts, and in the following part we will discuss studies dealing with fundamental aspects, but also mention proteome studies related to applied microbiology. Finally, we will envisage future perspectives of the proteome technology for studying yeasts, and draw major conclusion on the current status reached in this field of functional genomics.

Matros, Andrea; Mock, Hans-Peter

59

Yeast transcription factors Kevin Struhl  

E-print Network

Yeast transcription factors Kevin Struhl Harvard Medical School, Boston, USA Studies of yeast Transcriptional regulatory mechanisms are fundamentally similar in eukaryotic organisms from yeasts to humans (for reviews of yeast transcription, see [1,2]). Compo- nents of the chromatin template and the basic RNA

60

Yeast ecology of Kombucha fermentation  

Microsoft Academic Search

Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and

Ai Leng Teoh; Gillian Heard; Julian Cox

2004-01-01

61

RNAi in Budding Yeast  

E-print Network

RNA interference (RNAi), a gene-silencing pathway triggered by double-stranded RNA, is conserved in diverse eukaryotic species but has been lost in the model budding yeast Saccharomyces cerevisiae. Here, we show that RNAi ...

Drinnenberg, Ines A.

62

RNAi in budding yeast.  

PubMed

RNA interference (RNAi), a gene-silencing pathway triggered by double-stranded RNA, is conserved in diverse eukaryotic species but has been lost in the model budding yeast Saccharomyces cerevisiae. Here, we show that RNAi is present in other budding yeast species, including Saccharomyces castellii and Candida albicans. These species use noncanonical Dicer proteins to generate small interfering RNAs, which mostly correspond to transposable elements and Y' subtelomeric repeats. In S. castellii, RNAi mutants are viable but have excess Y' messenger RNA levels. In S. cerevisiae, introducing Dicer and Argonaute of S. castellii restores RNAi, and the reconstituted pathway silences endogenous retrotransposons. These results identify a previously unknown class of Dicer proteins, bring the tool of RNAi to the study of budding yeasts, and bring the tools of budding yeast to the study of RNAi. PMID:19745116

Drinnenberg, Ines A; Weinberg, David E; Xie, Kathleen T; Mower, Jeffrey P; Wolfe, Kenneth H; Fink, Gerald R; Bartel, David P

2009-10-23

63

[Penicillium-inhibiting yeasts].  

PubMed

The objective of this work was to establish the in vitro and in vivo inhibition of post-harvest pathogenic moulds by yeasts in order to make a biocontrol product. Post-harvest pathogenic moulds Penicillium digitatum, P. italicum, P. ulaiense, Phyllosticta sp., Galactomyces geotrichum and yeasts belonging to genera Brettanomyces, Candida, Cryptococcus, Kloeckera, Pichia, Rhodotorula were isolated from citrus fruits. Some yeasts strains were also isolated from other sources. The yeasts were identified by their macro and micro-morphology and physiological tests. The in vitro and in vivo activities against P. digitatum or P. ulaiense were different. Candida cantarellii and one strain of Pichia subpelliculosa produced a significant reduction of the lesion area caused by the pathogenic moulds P. digitatum and P. ulaiense, and could be used in a biocontrol product formulation. PMID:15786872

Benítez Ahrendts, M R; Carrillo, L

2004-01-01

64

Nitrile Metabolizing Yeasts  

NASA Astrophysics Data System (ADS)

Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing enzymes of yeasts.

Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

65

Mapping Yeast Transcriptional Networks  

PubMed Central

The term “transcriptional network” refers to the mechanism(s) that underlies coordinated expression of genes, typically involving transcription factors (TFs) binding to the promoters of multiple genes, and individual genes controlled by multiple TFs. A multitude of studies in the last two decades have aimed to map and characterize transcriptional networks in the yeast Saccharomyces cerevisiae. We review the methodologies and accomplishments of these studies, as well as challenges we now face. For most yeast TFs, data have been collected on their sequence preferences, in vivo promoter occupancy, and gene expression profiles in deletion mutants. These systematic studies have led to the identification of new regulators of numerous cellular functions and shed light on the overall organization of yeast gene regulation. However, many yeast TFs appear to be inactive under standard laboratory growth conditions, and many of the available data were collected using techniques that have since been improved. Perhaps as a consequence, comprehensive and accurate mapping among TF sequence preferences, promoter binding, and gene expression remains an open challenge. We propose that the time is ripe for renewed systematic efforts toward a complete mapping of yeast transcriptional regulatory mechanisms. PMID:24018767

Hughes, Timothy R.; de Boer, Carl G.

2013-01-01

66

Oxygen requirements of yeasts.  

PubMed Central

Type species of 75 yeast genera were examined for their ability to grow anaerobically in complex and mineral media. To define anaerobic conditions, we added a redox indicator, resazurin, to the media to determine low redox potentials. All strains tested were capable of fermenting glucose to ethanol in oxygen-limited shake-flask cultures, even those of species generally regarded as nonfermentative. However, only 23% of the yeast species tested grew under anaerobic conditions. A comparative study with a number of selected strains revealed that Saccharomyces cerevisiae stands out as a yeast capable of rapid growth at low redox potentials. Other yeasts, such as Torulaspora delbrueckii and Candida tropicalis, grew poorly mu max, 0.03 and 0.05 h-1, respectively) under anaerobic conditions in mineral medium supplemented with Tween 80 and ergosterol. The latter organisms grew rapidly under oxygen limitation and then displayed a high rate of alcoholic fermentation. It can be concluded that these yeasts have hitherto-unidentified oxygen requirements for growth. Images PMID:2082825

Visser, W; Scheffers, W A; Batenburg-van der Vegte, W H; van Dijken, J P

1990-01-01

67

Yeast killer systems.  

PubMed Central

The killer phenomenon in yeasts has been revealed to be a multicentric model for molecular biologists, virologists, phytopathologists, epidemiologists, industrial and medical microbiologists, mycologists, and pharmacologists. The surprisingly widespread occurrence of the killer phenomenon among taxonomically unrelated microorganisms, including prokaryotic and eukaryotic pathogens, has engendered a new interest in its biological significance as well as its theoretical and practical applications. The search for therapeutic opportunities by using yeast killer systems has conceptually opened new avenues for the prevention and control of life-threatening fungal diseases through the idiotypic network that is apparently exploited by the immune system in the course of natural infections. In this review, the biology, ecology, epidemiology, therapeutics, serology, and idiotypy of yeast killer systems are discussed. PMID:9227858

Magliani, W; Conti, S; Gerloni, M; Bertolotti, D; Polonelli, L

1997-01-01

68

L-arabinose fermenting yeast  

DOEpatents

An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. Methods of producing ethanol include utilizing these modified yeast strains. ##STR00001##

Zhang, Min (Lakewood, CO); Singh, Arjun (Lakewood, CO); Knoshaug, Eric (Golden, CO); Franden, Mary Ann (Centennial, CO); Jarvis, Eric (Boulder, CO); Suominen, Pirkko (Maple Grove, MN)

2010-12-07

69

Mitochondrial assembly in yeast.  

PubMed

The yeast Saccharomyces cerevisiae is likely to be the first organism for which a complete inventory of mitochondrial proteins and their functions can be drawn up. A survey of the 340 or so proteins currently known to be localised in yeast mitochondria reveals the considerable investment required to maintain the organelle's own genetic system, which itself contributes seven key components of the electron transport chain. Translation and respiratory complex assembly are particularly expensive processes, together requiring around 150 of the proteins so far known. Recent developments in both areas are reviewed and approaches to the identification of novel mitochondrial proteins are discussed. PMID:10376678

Grivell, L A; Artal-Sanz, M; Hakkaart, G; de Jong, L; Nijtmans, L G; van Oosterum, K; Siep, M; van der Spek, H

1999-06-01

70

Increased carotenoid production in Xanthophyllomyces dendrorhous G276 using plant extracts.  

PubMed

The red yeast Xanthophyllomyces dendrorhous (previously named Phaffia rhodozyma) produces astaxanthin pigment among many carotenoids. The mutant X. dendrorhous G276 was isolated by chemical mutagenesis. The mutant produced about 2.0 mg of carotenoid per g of yeast cell dry weight and 8.0 mg/L of carotenoid after 5 days batch culture with YM media; in comparison, the parent strain produced 0.66 mg/g of yeast cell dry weight and a carotenoid concentration of 4.5 mg/L. We characterized the utilization of carbon sources by the mutant strain and screened various edible plant extracts to enhance the carotenoid production. The addition of Perilla frutescens (final concentration, 5%) or Allium fistulosum extracts (final concentration, 1%) enhanced the pigment production to about 32 mg/L. In a batch fermentor, addition of Perilla frutescens extract reduced the cultivation time by two days compared to control (no extract), which usually required five-day incubation to fully produce astaxanthin. The results suggest that plant extracts such as Perilla frutescens can effectively enhance astaxanthin production. PMID:17483797

Kim, Soo-Ki; Lee, Jun-Hyeong; Lee, Chi-Ho; Yoon, Yoh-Chang

2007-04-01

71

Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi  

NASA Astrophysics Data System (ADS)

Several yeasts and yeast-like fungi are known to produce extracellular polysaccharides. Most of these contain D-mannose, either alone or in combination with other sugars or phosphate. A large chemical and structural variability is found between yeast species and even among different strains. The types of polymers that are synthesized can be chemically characterized as mannans, glucans, phosphoman-nans, galactomannans, glucomannans and glucuronoxylomannans. Despite these differences, almost all of the yeast exopolysaccharides display some sort of biological activity. Some of them have already applications in chemistry, pharmacy, cosmetics or as probiotic. Furthermore, some yeast exopolysaccharides, such as pullulan, exhibit specific physico-chemical and rheological properties, making them useful in a wide range of technical applications. A survey is given here of the production, the characteristics and the application potential of currently well studied yeast extracellular polysaccharides.

van Bogaert, Inge N. A.; de Maeseneire, Sofie L.; Vandamme, Erick J.

72

Yeast artificial chromosome cloning  

Microsoft Academic Search

Yeast artificial chromosome (YAC) cloning systems enable the cloning of DNA stretches of 50 to well over 2000 kb. This makes\\u000a it possible to study large intact regions of DNA in detail, by restriction mapping the YAC to produce a physical map and by\\u000a examining the YAC for coding sequences or genes. YACs are important for their ability to clone

Michele Ramsay

1994-01-01

73

Production of food yeast from starchy substrates  

Microsoft Academic Search

Fifteen yeast strains were selected for the production of food yeast from starchy substrates. From comparison with the amylolytic yeasts, a strain of Schwanniomyces castellii was selected and its characteristics are described.

A. Touzi; J. P. Prebois; G. Moulin; F. Deschamps; P. Galzy

1982-01-01

74

21 CFR 172.896 - Dried yeasts.  

...FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis ) and dried torula yeast (Candida utilis ) may be safely used in food provided the...

2014-04-01

75

New and emerging yeast pathogens.  

PubMed Central

The most common yeast species that act as agents of human disease are Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Cryptococcus neoformans. The incidence of infections by other yeasts has increased during the past decade. The most evident emerging pathogens are Malassezia furfur, Trichosporon beigelii, Rhodotorula species, Hansenula anomala, Candida lusitaniae, and Candida krusei. Organisms once considered environmental contaminants or only industrially important, such as Candida utilis and Candida lipolytica, have now been implicated as agents of fungemia, onychomycosis, and systemic disease. The unusual yeasts primarily infect immunocompromised patients, newborns, and the elderly. The role of central venous catheter removal and antifungal therapy in patient management is controversial. The antibiograms of the unusual yeasts range from resistant to the most recent azoles and amphotericin B to highly susceptible to all antifungal agents. Current routine methods for yeast identification may be insufficient to identify the unusual yeasts within 2 days after isolation. The recognition of unusual yeasts as agents of sometimes life-threatening infection and their unpredictable antifungal susceptibilities increase the burden on the clinical mycology laboratory to pursue complete species identification and MIC determinations. Given the current and evolving medical practices for management of seriously ill patients, further evaluations of the clinically important data about these yeasts are needed. PMID:8665465

Hazen, K C

1995-01-01

76

Brewer's yeast and sugarcane yeast as protein sources for dogs.  

PubMed

Brewer's yeast (BY), autolysed sugarcane yeast (ASCY) and integral sugar cane yeast (ISCY) were studied in two experiments as ingredients for dog diets. In the first experiment, 28 dogs were randomly assigned to four diets; one reference diet and three test diets containing 15% of BY, ASCY or ISCY and 85% of the reference diet (as-fed basis). The digestibilities of the yeasts were calculated by the substitution method. In the second experiment, 35 dogs were randomized to five diets with similar chemical composition but different levels of sugarcane yeast inclusion (0%, 7.5% ASCY, 15% ASCY, 7.5% ISCY and 15% ISCY). In both experiments, the coefficient of total tract apparent digestibility (CTTAD) of nutrients was determined through total collection of faeces. During experiment, two additional analyses of food palatability, nitrogen balance and urea postprandial responses were performed. The data were submitted to analysis of variance, and the means were compared by orthogonal or polynomial contrasts or Tukey's test (p < 0.05). In experiment 1, CTTAD of protein was lower for both sugarcane yeasts than for BY (p = 0.012), as was metabolizable energy content (p = 0.025). In experiment 2, a linear reduction in energy digestibility with ASCY inclusion (p = 0.05) was verified. Furthermore, faecal score and DM content were reduced with ISCY inclusion (p < 0.003). No effect of yeast inclusion on nitrogen balance or postprandial urea response was found. Also, the inclusion of 7.5% of ASCY or ISCY increased diet palatability (p < 0.01). Yeasts present adequate digestibility by dogs, but its effect on faecal formation needs to be considered. No clear advantage for the use of ASCY over ISCY was found. In conclusion, we find that sugarcane yeast is suitable for inclusion in dog food and can enhance the overall palatability of the diet. PMID:24304448

Martins, M S; Sakomura, N K; Souza, D F; Filho, F O R; Gomes, M O S; Vasconcellos, R S; Carciofi, A C

2014-10-01

77

Yeast ecology of Kombucha fermentation.  

PubMed

Kombucha is a traditional fermentation of sweetened tea, involving a symbiosis of yeast species and acetic acid bacteria. Despite reports of different yeast species being associated with the fermentation, little is known of the quantitative ecology of yeasts in Kombucha. Using oxytetracycline-supplemented malt extract agar, yeasts were isolated from four commercially available Kombucha products and identified using conventional biochemical and physiological tests. During the fermentation of each of the four products, yeasts were enumerated from both the cellulosic pellicle and liquor of the Kombucha. The number and diversity of species varied between products, but included Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii and Zygosaccharomyces bailii. While these yeast species are known to occur in Kombucha, the enumeration of each species present throughout fermentation of each of the four Kombucha cultures demonstrated for the first time the dynamic nature of the yeast ecology. Kombucha fermentation is, in general, initiated by osmotolerant species, succeeded and ultimately dominated by acid-tolerant species. PMID:15282124

Teoh, Ai Leng; Heard, Gillian; Cox, Julian

2004-09-01

78

Yeast Metabolism Lab Mrs. Zimmerman  

E-print Network

Energy from sunlight #12;Respiration #12;Cellular Respiration C6H12O6 + 6 O2 6 CO2 + 6 H2O + energyYeast Metabolism Lab Mrs. Zimmerman 10/22/10 #12;Photosynthesis 6 CO2 + 6 H2O C6H12O6 + 6 O2 Oxygen Glucose Carbon Dioxide Water Energy #12;Yeast · Unicellular · Eukaryotic (like us) · Kingdom Fungi

Rose, Michael R.

79

Study of amyloids using yeast  

PubMed Central

Summary Saccharomyces cerevisiae has been a useful model organism in such fields as the cell cycle, regulation of transcription, protein trafficking and cell biology, primarily because of its ease of genetic manipulation. This is no less so in the area of amyloid studies. The endogenous yeast amyloids described to date include prions, infectious proteins (Table 1), and some cell wall proteins (1). and amyloids of humans and a fungal prion have also been studied using the yeast system. Accordingly, the emphasis of this chapter will be on genetic, biochemical, cell biological and physical methods particularly useful in the study of yeast prions and other amyloids studied in yeast. We limit our description of these methods to those aspects which have been most useful in studying yeast prions, citing more detailed expositions in the literature. Volumes on yeast genetics methods (2–4), and on amyloids and prions (5, 6) are useful, and Masison has edited a volume of Methods on “Identification, analysis and characterization of fungal prions” which covers some of this territory (7). We also outline some useful physical methods, pointing the reader to more extensive and authoratative descriptions. PMID:22528100

Wickner, Reed B.; Kryndushkin, Dmitry; Shewmaker, Frank; McGlinchey, Ryan; Edskes, Herman K.

2012-01-01

80

Yeast models for amyloid disease.  

PubMed

Saccharomyces cerevisiae (baker's yeast) is a well-established eukaryotic model organism, which has significantly contributed to our understanding of mechanisms that drive numerous core cellular processes in higher eukaryotes. Moreover, this has led to a greater understanding of the underlying pathobiology associated with disease in humans. This tractable model offers an abundance of analytical capabilities, including a vast array of global genetics and molecular resources that allow genome-wide screening to be carried out relatively simply and cheaply. A prime example of the versatility and potential for applying yeast technologies to explore a mammalian disease is in the development of yeast models for amyloid diseases such as Alzheimer's, Parkinson's and Huntington's. The present chapter provides a broad overview of high profile human neurodegenerative diseases that have been modelled in yeast. We focus on some of the most recent findings that have been developed through genetic and drug screening studies using yeast genomic resources. Although this relatively simple unicellular eukaryote seems far removed from relatively complex multicellular organisms such as mammals, the conserved mechanisms for how amyloid exhibits toxicity clearly underscore the value of carrying out such studies in yeast. PMID:25131588

Panaretou, Barry; Jones, Gary W

2014-01-01

81

Yeasts preservation: alternatives for lyophilisation.  

PubMed

The aim of the study was to compare the effect of two low-cost, low technology traditional methods for drying starter cultures with standard lyophilisation. Lyophilised yeast cultures and yeast cultures preserved in dry rice cakes and dry plant fibre strands were examined for viable cell counts during 6 months storage at 4 and 25 °C. None of the yeast cultures showed a significant loss in viable cell count during 6 months of storage at 4 °C upon lyophilisation and preservation in dry rice cakes. During storage at 25 °C in the dark, yeast cultures preserved in dry rice cakes, and lyophilised cultures of Saccharomyces cerevisiae and Issatchenkia orientalis showed no significant loss of viable cells up to 4 months of storage. Yeast cultures preserved in dry plant fibre strands had the greatest loss of viable count during the 6 months of storage at 25 °C. Preservation of yeasts cultures in dry rice cakes provided better survival during storage at 4 °C than lyophilisation. The current study demonstrated that traditional methods can be useful and effective for starter culture preservation in small-scale, low-tech applications. PMID:22806747

Nyanga, Loveness K; Nout, Martinus J R; Smid, Eddy J; Boekhout, Teun; Zwietering, Marcel H

2012-11-01

82

Nuclear transport of yeast proteasomes.  

PubMed

Proteasomes are conserved protease complexes enriched in the nuclei of dividing yeast cells, a major site for protein degradation. If yeast cells do not proliferate and transit to quiescence, metabolic changes result in the dissociation of proteasomes into proteolytic core and regulatory complexes and their sequestration into motile cytosolic proteasome storage granuli. These granuli rapidly clear with the resumption of growth, releasing the stored proteasomes, which relocalize back to the nucleus to promote cell cycle progression. Here, I report on three models of how proteasomes are transported from the cytoplasm into the nucleus of yeast cells. The first model applies for dividing yeast and is based on the canonical pathway using classical nuclear localization sequences of proteasomal subcomplexes and the classical import receptor importin/karyopherin ??. The second model applies for quiescent yeast cells, which resume growth and use Blm10, a HEAT-like repeat protein structurally related to karyopherin ?, for nuclear import of proteasome core particles. In the third model, the fully-assembled proteasome is imported into the nucleus. Our still marginal knowledge about proteasome dynamics will inspire the discussion on how protein degradation by proteasomes may be regulated in different cellular compartments of dividing and quiescent eukaryotic cells. PMID:25333764

Enenkel, Cordula

2014-01-01

83

Cdc42 Oscillations in Yeasts  

NSDL National Science Digital Library

A fundamental problem in cell biology is how cells define one or several discrete sites of polarity. Through mechanisms involving positive and negative feedback, the small Rho-family guanosine triphosphatase Cdc42 breaks symmetry in round budding yeast cells to define a single site of polarized cell growth. However, it is not clear how cells can define multiple sites of polarization concurrently. We discuss a study in which rod-shaped fission yeast cells, which naturally polarize growth at their two cell ends, exhibited oscillations of Cdc42 activity between these sites. We compare these findings with similar oscillatory behavior of Cdc42 detected in budding yeast cells and discuss the possible mechanism and functional outputs of these oscillations.

Felipe O. Bendezu (Switzerland;University of Lausanne REV); Sophie G. Martin (Switzerland;University of Lausanne REV)

2012-12-04

84

The yeasts of cheese brines.  

PubMed

A total of 365 yeasts were isolated from the brines of soft, semihard and hard cheeses from different manufacturers. Identification was based on 131 characteristics, primarily employing a method with microtitration plates. Most brines exhibited a characteristic yeast flora. The predominant strains proved to be mainly Debaryomyces hansenii and Candida versatilis. In a few brines Trichosporon beigelii, C. rugosa, C. intermedia, Kluyveromyces marxianus, Saccharomyces sp. and C. tenuis/polymorpha were predominant. Also of importance were C. tropicalis, C. parapsilosis, C. zeylanoides, Issatchenkia orientalis and Geotrichum klebahnii. Not all strains could be clearly identified. Lists of characters are provided for subdividing D. hansenii and T. beigelii. The specificity of the yeast flora of brines is assumed to contribute to the sensory variety of cheeses. PMID:2282287

Seiler, H; Busse, M

1990-12-01

85

280 EXPRESSION IN YEAST [23] [23] Manipulating Yeast Genome Using Plasmid Vectors  

E-print Network

280 EXPRESSION IN YEAST [23] [23] Manipulating Yeast Genome Using Plasmid Vectors By TIM STEARNS, HONG MA, and DAVID BOTSTEIN The yeast Saccharomyces cerevisiae has proved to be a popular high status of yeast as an experimental system is in large part due to the work of the many geneticists

Botstein, David

86

APPENDIX 4LGrowth and Manipulation of Yeast PREPARATION OF SELECTED YEAST MEDIA  

E-print Network

APPENDIX 4LGrowth and Manipulation of Yeast PREPARATION OF SELECTED YEAST MEDIA Like Escherichia coli, yeast can be grown in either liquid media or on the surface of (or embedded in) solid agar plates. Yeast cells grow well on a minimal medium containing dextrose (glucose) as a carbon source and salts

Winston, Fred

87

Pre-Absorbing Antibody with Yeast Cells Preparation of Fixed Yeast  

E-print Network

106 Pre-Absorbing Antibody with Yeast Cells Preparation of Fixed Yeast 1. Plan to do steps 1-10 in the yeast immunofluorescence method. But, start with 100 mls of cells at OD600=0.2. Then, do all steps in quadruplicate. Do pretreatment, and digest cells for 10 minutes. 2. Pool all yeast in SPC + Pics in one

Aris, John P.

88

The Yeast Nuclear Pore Complex  

PubMed Central

An understanding of how the nuclear pore complex (NPC) mediates nucleocytoplasmic exchange requires a comprehensive inventory of the molecular components of the NPC and a knowledge of how each component contributes to the overall structure of this large molecular translocation machine. Therefore, we have taken a comprehensive approach to classify all components of the yeast NPC (nucleoporins). This involved identifying all the proteins present in a highly enriched NPC fraction, determining which of these proteins were nucleoporins, and localizing each nucleoporin within the NPC. Using these data, we present a map of the molecular architecture of the yeast NPC and provide evidence for a Brownian affinity gating mechanism for nucleocytoplasmic transport. PMID:10684247

Rout, Michael P.; Aitchison, John D.; Suprapto, Adisetyantari; Hjertaas, Kelly; Zhao, Yingming; Chait, Brian T.

2000-01-01

89

Chromatin and Transcription in Yeast  

PubMed Central

Understanding the mechanisms by which chromatin structure controls eukaryotic transcription has been an intense area of investigation for the past 25 years. Many of the key discoveries that created the foundation for this field came from studies of Saccharomyces cerevisiae, including the discovery of the role of chromatin in transcriptional silencing, as well as the discovery of chromatin-remodeling factors and histone modification activities. Since that time, studies in yeast have continued to contribute in leading ways. This review article summarizes the large body of yeast studies in this field. PMID:22345607

Rando, Oliver J.; Winston, Fred

2012-01-01

90

Modelling the Yeast Interactome Vuk Janjic1  

E-print Network

Modelling the Yeast Interactome Vuk Janjic´1 , Roded Sharan2 & Natasa Przulj1 1 Department of any empirical observation regarding those networks. Here, we perform a comprehensive analysis of yeast complexity (human and yeast); (3) clear topological difference is present between PPI networks

Shamir, Ron

91

Yeast communities associated with stingless bees  

Microsoft Academic Search

The yeast communities associated with the stingless bees Tetragonisca angustula, Melipona quadrifasciata and Frieseomelitta varia were studied. The bees T. angustula and F. varia showed a strong association with the yeast Starmerella meliponinorum. M. quadrifasciata more frequently carried a species related to Candida apicola, but also vectored low numbers of S. meliponinorum. Some of the yeasts isolated from adult bees

Carlos A Rosa; Marc-André Lachance; Jana??na O. C Silva; Ana Carolina P Teixeira; Marjorie M Marini; Yasmine Antonini; Rogerio P Martins

2003-01-01

92

Red yeast rice: a new hypolipidemic drug  

Microsoft Academic Search

Red yeast rice is a source of fermented pigment with possible bioactive effect. Evidence shows that fermented red yeast rice lowers cholesterol levels moderately compared to other statin drugs, but with the added advantage of causing less adverse effects. A review of the body of evidence surrounding the properties of red yeast rice underscores its potential as a new alternative

Mélanie Journoud; Peter J. H Jones

2004-01-01

93

Yeast community survey in the Tagus estuary  

Microsoft Academic Search

The yeast community in the waters of the Tagus estuary, Portugal, was followed for over a year in order to assess its dynamics. Yeast occurrence and incidence were measured and this information was related to relevant environmental data. Yeast occurrence did not seem to depend upon tides, but river discharge had a dramatic impact both on the density and diversity

João M. G. C. F. de Almeida

2005-01-01

94

Observations on the Yeast Lipomyces  

Microsoft Academic Search

IN 1946, Starkey1 isolated and described a soil yeast characterized by a peculiar method of spore formation after a relatively long period of growth on solid medium. Large, round vegetative cells containing fat globules gave rise to irregularly shaped protuberances in which were afterwards formed 4-16 or more lightly pigmented spores. Lodder and Kregervan Rij2 considered these spores to be

Catherine Roberts

1957-01-01

95

Genetically modified industrial yeast ready for application.  

PubMed

Tremendous progress in the genetic engineering of yeast had been achieved at the end of 20th century, including the complete genome sequence, genome-wide gene expression profiling, and whole gene disruption strains. Nevertheless, genetically modified (GM) baking, brewing, wine, and sake yeasts have not, as yet, been used commercially, although numerous industrial recombinant yeasts have been constructed. The recent progress of genetic engineering for the construction of GM yeast is reviewed and possible requirements for their application are discussed. 'Self-cloning' yeast will be the most likely candidate for the first commercial application of GM microorganisms in food and beverage industries. PMID:16233347

Akada, Rinji

2002-01-01

96

Occurrence and Growth of Yeasts in Yogurts  

PubMed Central

Yogurts purchased from retail outlets were examined for the presence of yeasts by being plated onto oxytetracycline malt extract agar. Of the 128 samples examined, 45% exhibited yeast counts above 103 cells per g. A total of 73 yeast strains were isolated and identified as belonging to the genera Torulopsis, Kluyveromyces, Saccharomyces, Candida, Rhodotorula, Pichia, Debaryomyces, and Sporobolomyces. Torulopsis candida and Kluyveromyces fragilis were the most frequently isolated species, followed by Saccharomyces cerevisiae, Rhodotorula rubra, Kluyveromyces lactis, and Torulopsis versatilis. The growth of yeasts in yogurts was related to the ability of the yeasts to grow at refrigeration temperatures, to ferment lactose and sucrose, and to hydrolyze milk casein. Most yeast isolates grew in the presence of 100 ?g of sorbate and benzoate preservatives per ml. Higher yeast counts from yogurts were obtained when the yogurts were plated onto oxytetracycline malt extract agar than when they were plated onto acidified malt extract agar. PMID:16345853

Suriyarachchi, V. R.; Fleet, G. H.

1981-01-01

97

Preparation of extracts from yeast.  

PubMed

Because yeast is exceptionally well suited to genetic analysis, both classical and molecular, it is an attractive system for expressing recombinant animal proteins for purification purposes. Methods available for lysing yeast cells include autolysis, pressure cells (e.g., French press), abrasives (glass bead vortexing), and enzymatic lysis (e.g., zymolase). One of the simplest methods, discussed in this protocol, involves the abrasive action of well-agitated glass beads. This is a very effective method for both low volumes (e.g., <1 mL using a microcentrifuge tube) and many liters using a specialized DynoMill apparatus. Cell breakage is typically >95%, as assessed by phase-contrast microscopy. PMID:21205845

Simpson, Richard J

2011-01-01

98

Oxidative stress responses in yeast  

Microsoft Academic Search

Yeast, and especially S. cerevisiae, is a unique eukaryotic model organism for studying oxidative stress and its cellular responses. S. cerevisiae has become a very powerful tool to decipher the complexity of these biologically important responses, because it offers the\\u000a relative simplicity of a single celled eukaryotic organism that enables the combination and integration of genetic, biochemical,\\u000a physico-chemical, cell biological,

Michel B. Toledano; Agnes Delaunay; Benoit Biteau; Daniel Spector; Dulce Azevedo

99

Yeast adaptation on softwood prehydrolysate  

Microsoft Academic Search

Several strains and genera of yeast, includingSaccharomyces cerevisiae D5A,Pachysolen tannophilus, S. cerevisiae K-l,Brettanomyces custersii, Candida shehatae, andCandida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. Selected softwood species found in forest underbrush\\u000a of the western United States, which contain predominantly hexosan hemicellulose, were studied. This phase of the work emphasized\\u000a debarked Douglas fir. The two best initial isolates

Fcred A. Keller; Delicia Bates; Ray Ruiz; Quang Nguyen

1998-01-01

100

Biodegradation of Oil Pollutants by Yeasts and Yeast-Like Fungi.  

National Technical Information Service (NTIS)

In exploring the feasibility of the use of microbial systems for the facilitated biodegradation of waste oils, yeasts and yeast-like fungi from marine, freshwater and terrestrial sources were screened for their ability to utilize hydrocarbons. Mixed cultu...

D. G. Ahearn, N. H. Berner

1978-01-01

101

Assembly of eukaryotic algal chromosomes in yeast  

PubMed Central

Background Synthetic genomic approaches offer unique opportunities to use powerful yeast and Escherichia coli genetic systems to assemble and modify chromosome-sized molecules before returning the modified DNA to the target host. For example, the entire 1 Mb Mycoplasma mycoides chromosome can be stably maintained and manipulated in yeast before being transplanted back into recipient cells. We have previously demonstrated that cloning in yeast of large (>?~?150 kb), high G?+?C (55%) prokaryotic DNA fragments was improved by addition of yeast replication origins every ~100 kb. Conversely, low G?+?C DNA is stable (up to at least 1.8 Mb) without adding supplemental yeast origins. It has not been previously tested whether addition of yeast replication origins similarly improves the yeast-based cloning of large (>150 kb) eukaryotic DNA with moderate G?+?C content. The model diatom Phaeodactylum tricornutum has an average G?+?C content of 48% and a 27.4 Mb genome sequence that has been assembled into chromosome-sized scaffolds making it an ideal test case for assembly and maintenance of eukaryotic chromosomes in yeast. Results We present a modified chromosome assembly technique in which eukaryotic chromosomes as large as ~500 kb can be assembled from cloned ~100 kb fragments. We used this technique to clone fragments spanning P. tricornutum chromosomes 25 and 26 and to assemble these fragments into single, chromosome-sized molecules. We found that addition of yeast replication origins improved the cloning, assembly, and maintenance of the large chromosomes in yeast. Furthermore, purification of the fragments to be assembled by electroelution greatly increased assembly efficiency. Conclusions Entire eukaryotic chromosomes can be successfully cloned, maintained, and manipulated in yeast. These results highlight the improvement in assembly and maintenance afforded by including yeast replication origins in eukaryotic DNA with moderate G?+?C content (48%). They also highlight the increased efficiency of assembly that can be achieved by purifying fragments before assembly. PMID:24325901

2013-01-01

102

Yeasts in floral nectar: a quantitative survey  

PubMed Central

Background and Aims One peculiarity of floral nectar that remains relatively unexplored from an ecological perspective is its role as a natural habitat for micro-organisms. This study assesses the frequency of occurrence and abundance of yeast cells in floral nectar of insect-pollinated plants from three contrasting plant communities on two continents. Possible correlations between interspecific differences in yeast incidence and pollinator composition are also explored. Methods The study was conducted at three widely separated areas, two in the Iberian Peninsula (Spain) and one in the Yucatán Peninsula (Mexico). Floral nectar samples from 130 species (37–63 species per region) in 44 families were examined microscopically for the presence of yeast cells. For one of the Spanish sites, the relationship across species between incidence of yeasts in nectar and the proportion of flowers visited by each of five major pollinator categories was also investigated. Key Results Yeasts occurred regularly in the floral nectar of many species, where they sometimes reached extraordinary densities (up to 4 × 105 cells mm?3). Depending on the region, between 32 and 44 % of all nectar samples contained yeasts. Yeast cell densities in the order of 104 cells mm?3 were commonplace, and densities >105 cells mm?3 were not rare. About one-fifth of species at each site had mean yeast cell densities >104 cells mm?3. Across species, yeast frequency and abundance were directly correlated with the proportion of floral visits by bumble-bees, and inversely with the proportion of visits by solitary bees. Conclusions Incorporating nectar yeasts into the scenario of plant–pollinator interactions opens up a number of intriguing avenues for research. In addition, with yeasts being as ubiquitous and abundant in floral nectars as revealed by this study, and given their astounding metabolic versatility, studies focusing on nectar chemical features should carefully control for the presence of yeasts in nectar samples. PMID:19208669

Herrera, Carlos M.; de Vega, Clara; Canto, Azucena; Pozo, Maria I.

2009-01-01

103

Construction of an efficient amylolytic industrial yeast strain containing DNA exclusively derived from yeast  

Microsoft Academic Search

An amylolytic industrial yeast strain of Saccharomyces cerevisiae containing the Schwanniomyces occidentalis SWA2 amylase gene was generated. The new strain contains DNA derived exclusively from yeast and expresses a high starch hydrolyzing activity. Yeast transformation was carried out by an integrative process targeted to a dispensable upstream region of the ILV2 locus, which determines sulfometuron resistance. The SWA2 enzyme was

D Mar??n; A Jiménez; M Fernández Lobato

2001-01-01

104

Networking proteins in yeast Tony R. Hazbun* and Stanley Fields  

E-print Network

of a reporter gene whose product is easily assayed, generally by growth of the yeast on a defined media. Ito et,000 predicted yeast proteins. They generated 62 pools of each type of yeast transformant, containing up to 96

Dunham, Maitreya

105

Drosophila Regulate Yeast Density and Increase Yeast Community Similarity in a Natural Substrate  

PubMed Central

Drosophila melanogaster adults and larvae, but especially larvae, had profound effects on the densities and community structure of yeasts that developed in banana fruits. Pieces of fruit exposed to adult female flies previously fed fly-conditioned bananas developed higher yeast densities than pieces of the same fruits that were not exposed to flies, supporting previous suggestions that adult Drosophila vector yeasts to new substrates. However, larvae alone had dramatic effects on yeast density and species composition. When yeast densities were compared in pieces of the same fruits assigned to different treatments, fruits that developed low yeast densities in the absence of flies developed significantly higher yeast densities when exposed to larvae. Across all of the fruits, larvae regulated yeast densities within narrow limits, as compared to a much wider range of yeast densities that developed in pieces of the same fruits not exposed to flies. Larvae also affected yeast species composition, dramatically reducing species diversity across fruits, reducing variation in yeast communities from one fruit to the next (beta diversity), and encouraging the consistent development of a yeast community composed of three species of yeast (Candida californica, C. zemplinina, and Pichia kluvyeri), all of which were palatable to larvae. Larvae excreted viable cells of these three yeast species in their fecal pools, and discouraged the growth of filamentous fungi, processes which may have contributed to their effects on the yeast communities in banana fruits. These and other findings suggest that D. melanogaster adults and their larval offspring together engage in ‘niche construction’, facilitating a predictable microbial environment in the fruit substrates in which the larvae live and develop. PMID:22860093

Stamps, Judy A.; Yang, Louie H.; Morales, Vanessa M.; Boundy-Mills, Kyria L.

2012-01-01

106

Yeast Breads: Made at Home.  

E-print Network

are developed by stirring and beating the batter I .-. combined and only enough flour is added to than by kneading. Batters are allowed tc make a thick batter. This batter is set in a warm either in the bowl or baking pan. Combining i ngre for bre rolls...- ing, since it is an accurate guide in keeping the correct temperature. Active dry yeast is dissolved in warm, not hot, water. The "feel" test may be used by experienced bread makers. Place a drop of liquid on the inside of the wrist. If the liquid...

Cox, Maeona; Harris, Jimmie Nell; Reasonover, Frances; Mason, Lousie

1957-01-01

107

Yeast Breads: Made at Home.  

E-print Network

the bread. Sugar helps give a golden brown color to the crust. fat Some type of fat or oil is included in nearly all yeast bread. It conditions the gluten, making other ingredients Eggs give extra flavor and richness and s! to the food value.... They help produce a f~r delicate texture and a golden brown crust. Rn' and breads made with egg whites and \\\\a. usually have an open grain and a somewhat tila' crisp crust. For various kinds of fancy bre;l' and rolls, fruits, nuts, spices and other...

Reasonover, Frances

1971-01-01

108

Fermentation studies using Saccharomyces diastaticus yeast strains  

SciTech Connect

The yeast species, Saccharomyces diastaticus, has the ability to ferment starch and dextrin, because of the extracellular enzyme, glucoamylase, which hydrolyzes the starch/dextrin to glucose. A number of nonallelic genes--DEX 1, DEX 2, and dextrinase B which is allelic to STA 3--have been isolated, which impart to the yeast the ability to ferment dextrin. Various diploid yeast strains were constructed, each being either heterozygous or homozygous for the individual dextrinase genes. Using 12 (sup 0) plato hopped wort (30% corn adjunct) under agitated conditions, the fermentation rates of the various diploid yeast strains were monitored. A gene-dosage effect was exhibited by yeast strains containing DEX 1 or DEX 2, however, not with yeast strains containing dextrinase B (STA 3). The fermentation and growth rates and extents were determined under static conditions at 14.4 C and 21 C. With all yeast strains containing the dextrinase genes, both fermentation and growth were increased at the higher incubation temperature. Using 30-liter fermentors, beer was produced with the various yeast strains containing the dextrinase genes and the physical and organoleptic characteristics of the products were determined. The concentration of glucose in the beer was found to increase during a 3-mo storage period at 21 C, indicating that the glucoamylase from Saccharomyces diastaticus is not inactivated by pasteurization. (Refs. 36).

Erratt, J.A.; Stewart, G.G.

1981-01-01

109

Evolutionary constraints on yeast protein size  

Microsoft Academic Search

BACKGROUND: Despite a strong evolutionary pressure to reduce genome size, proteins vary in length over a surprisingly wide range also in very compact genomes. Here we investigated the evolutionary forces that act on protein size in the yeast Saccharomyces cerevisiae utilizing a system-wide bioinformatics approach. Data on yeast protein size was compared to global experimental data on protein expression, phenotypic

Jonas Warringer; Anders Blomberg

2006-01-01

110

Can yeast transcriptomics help improve wine fermentation?  

Microsoft Academic Search

Wine fermentation is a dynamic and complex process in which the yeast cell is subjected to multiple stress conditions. A successful adaptation involves changes in gene expression profiles where a large number of genes are up- or down-regulated. Functional genomic approaches are com- monly used to obtain global gene expression profiles, providing a comprehensive view of yeast physiology. We used

C. Varela; J. Cárdenas; E. Agosin

111

Oily yeasts as oleaginous cell factories.  

PubMed

Oily yeasts have been described to be able to accumulate lipids up to 20% of their cellular dry weight. These yeasts represent a minor proportion of the total yeast population, and only 5% of them have been reported as able to accumulate more than 25% of lipids. The oily yeast genera include Yarrowia, Candida, Rhodotorula, Rhodosporidium, Cryptococcus, Trichosporon, and Lipomyces. More specifically, examples of oleaginous yeasts include the species: Lipomyces starkeyi, Rhodosporidium toruloides, Rhodotorula glutinis, and Yarrowia lipolytica. Yeast do exhibit advantages for lipid production over other microbial sources, namely, their duplication times are usually lower than 1 h, are much less affected than plants by season or climate conditions, and their cultures are more easily scaled up than those of microalgae. Additionally, some oily yeasts have been reported to accumulate oil up to 80% of their dry weight and can indeed generate different lipids from different carbon sources or from lipids present in the culture media. Thus, they can vary their lipid composition by replacing the fatty acids present in their triglycerides. Due to the diversity of microorganisms and growth conditions, oily yeasts can be useful for the production of triglycerides, surfactants, or polyunsaturated fatty acids. PMID:21465305

Ageitos, Jose Manuel; Vallejo, Juan Andres; Veiga-Crespo, Patricia; Villa, Tomas G

2011-05-01

112

Identification of yeasts isolated from poultry meat.  

PubMed

In an assessment of the potential role of yeasts in the spoilage of poultry meat, the population and species diversity of yeasts were determined on 50 commercial raw and processed chicken and turkey product samples. Initial populations (log10 cfu/g) ranged from less than 0.1 to 2.9, and increased by the expiration date to 0.4 to 5.1, respectively. 145 of 152 isolates were identified as belonging to 12 species. Yarrowia lipolytica and Candida zeylanoides were predominant, accounting for 39% and 26% of the isolates, respectively. Six different species of basidiomycetous yeasts were determined representing 24% of the isolates. The ability of the predominant yeast species to grow at refrigeration temperatures and their proteolytic and lipolytic activies suggest that yeasts may play a more significant role than previously recognised in the spoilage of poultry products. PMID:11426853

Deák, T

2001-01-01

113

Global nucleosome occupancy in yeast  

PubMed Central

Background Although eukaryotic genomes are generally thought to be entirely chromatin-associated, the activated PHO5 promoter in yeast is largely devoid of nucleosomes. We systematically evaluated nucleosome occupancy in yeast promoters by immunoprecipitating nucleosomal DNA and quantifying enrichment by microarrays. Results Nucleosome depletion is observed in promoters that regulate active genes and/or contain multiple evolutionarily conserved motifs that recruit transcription factors. The Rap1 consensus was the only binding motif identified in a completely unbiased search of nucleosome-depleted promoters. Nucleosome depletion in the vicinity of Rap1 consensus sites in ribosomal protein gene promoters was also observed by real-time PCR and micrococcal nuclease digestion. Nucleosome occupancy in these regions was increased by the small molecule rapamycin or, in the case of the RPS11B promoter, by removing the Rap1 consensus sites. Conclusions The presence of transcription factor-binding motifs is an important determinant of nucleosome depletion. Most motifs are associated with marked depletion only when they appear in combination, consistent with a model in which transcription factors act collaboratively to exclude nucleosomes and gain access to target sites in the DNA. In contrast, Rap1-binding sites cause marked depletion under steady-state conditions. We speculate that nucleosome depletion enables Rap1 to define chromatin domains and alter them in response to environmental cues. PMID:15345046

Bernstein, Bradley E; Liu, Chih Long; Humphrey, Emily L; Perlstein, Ethan O; Schreiber, Stuart L

2004-01-01

114

Cassava starch maltodextrinization/monomerization through thermopressurized aqueous phosphoric acid hydrolysis.  

PubMed

Kinetic conditions were established for the depolymerization of cassava starch for the production of maltodextrins and glucose syrups. Thin-layer chromatography and high-performance liquid chromatography analyses corroborated that the proper H3PO4 strength and thermopressurization range (e.g., 142-170 degrees C; 2.8-6.8 atm) can be successfully explored for such hydrolytic purposes of native starch granules. Because phosphoric acid can be advantageously maintained in the hydrolysate and generates, after controlled neutralization with ammonia, the strategic nutrient triplet for industrial fermentations (C, P, N), this pretreatment strategy can be easily recognized as a recommended technology for hydrolysis and upgrading of starch and other plant polysaccharides. Compared to the classic catalysts, the mandatory desalting step (chloride removal by expensive anion-exchange resin or sulfate precipitation as the calcium-insoluble salt) can be avoided. Furthermore, properly diluted phosphoric acid is well known as an allowable additive in several popular soft drinks such as colas since its acidic feeling in the mouth is compatible and synergistic with both natural and artificial sweeteners. Glycosyrups from phosphorolyzed cassava starch have also been upgraded to high-value single-cell protein such as the pigmented yeast biomass of Xanthophyllomyces dendrorhous (Phaffia rhodozyma), whose astaxanthin (diketo-dihydroxy-beta-carotene) content may reach 0.5-1.0 mg/g of dry yeast cell. This can be used as an ideal complement for animal feeding as well as a natural staining for both fish farming (meat) and poultry (eggs). PMID:11963875

Fontana, J D; Passos, M; Baron, M; Mendes, S V; Ramos, L P

2001-01-01

115

Accelerating Yeast Prion Biology using Droplet Microfluidics  

NASA Astrophysics Data System (ADS)

Prions are infectious proteins in a misfolded form, that can induce normal proteins to take the misfolded state. Yeast prions are relevant, as a model of human prion diseases, and interesting from an evolutionary standpoint. Prions may also be a form of epigenetic inheritance, which allow yeast to adapt to stressful conditions at rates exceeding those of random mutations and propagate that adaptation to their offspring. Encapsulation of yeast in droplet microfluidic devices enables high-throughput measurements with single cell resolution, which would not be feasible using bulk methods. Millions of populations of yeast can be screened to obtain reliable measurements of prion induction and loss rates. The population dynamics of clonal yeast, when a fraction of the cells are prion expressing, can be elucidated. Furthermore, the mechanism by which certain strains of bacteria induce yeast to express prions in the wild can be deduced. Integrating the disparate fields of prion biology and droplet microfluidics reveals a more complete picture of how prions may be more than just diseases and play a functional role in yeast.

Ung, Lloyd; Rotem, Assaf; Jarosz, Daniel; Datta, Manoshi; Lindquist, Susan; Weitz, David

2012-02-01

116

Original article Effect of a viable yeast culture on digestibility  

E-print Network

cultures to improve productivity in livestock husbandry. In comparison with antimicrobial agents, yeast that the effect of yeast culture on ru- men fermentation may depend on the nature of.the diet. Living yeast cell culture offers a natural alternative to manipulate animal performance. Positive effects of a yeast culture

Boyer, Edmond

117

Computational Predictions of Structures of Multichromosomes of Budding Yeast  

E-print Network

Computational Predictions of Structures of Multichromosomes of Budding Yeast (Accepted, Conf Proc of budding yeast nucleus. We successfully generated a large number of model genomes of yeast with appropriate yeast genome realistically. The model developed here provides a general computational framework

Liang, Jie

118

Yeast (in press) Published online in Wiley InterScience  

E-print Network

Yeast Yeast (in press) Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/yea.1502 Yeast Functional Analysis Report A suite of Gateway cloning vectors for high of overexpression plasmids containing the entire complement of yeast open reading frames (ORFs) have recently been

Lycan, Deborah E.

119

Original article Screening for the potential probiotic yeast strains  

E-print Network

Original article Screening for the potential probiotic yeast strains from raw milk to assimilate yeast strains, isolated from raw milk, were tested to obtain potential probiotic yeasts for assimilating cholesterol. During in vitro tests, 17 yeast strains were capable of growth in bile salt solutions, and most

Paris-Sud XI, Université de

120

Yeast adaptation on softwood prehydrolysate.  

PubMed

Several strains and genera of yeast, including Saccharomyces cerevisiae D5A, Pachysolen tannophilus, S. cerevisiae K-1, Brettanomyces custersii, Candida shehatae, and Candida acidothermophilum, are screened for growth on dilute acid-pretreated softwood prehydrolysate. Selected softwood species found in forest underbrush of the western United States, which contain predominantly hexosan hemicellulose, were studied. This phase of the work emphasized debarked Douglas fir. The two best initial isolates were gradually selected for improved growth by adaptation to increasing prehydrolysate concentrations in batch culture, with due consideration of nutrient requirements. Microaerophilic conditions were evaluated to encourage tolerance of pretreatment hydrolysate, as well as ethanol product. Adaptation and simultaneous saccharification and fermentation (SSF) results are used to illustrate improved performance with an adapted strain, compared to the wild type. PMID:9627379

Keller, F A; Bates, D; Ruiz, R; Nguyen, Q

1998-01-01

121

Extracellular Deoxyribonuclease Production by Yeasts  

PubMed Central

A total of 20 genera of yeasts and yeastlike organisms were tested for their ability to produce an extracellular deoxyribonuclease. Results indicate that ability to produce the enzyme appears to be a specific characteristic of the three genera Rhodotorula, Cryptococcus, and Tremella. A single strain of Endomycopsis fibuligera was also shown to be positive for the enzyme. In comparing the ability of the organisms to excrete extracellular deoxyribonuclease with their ability to produce urease, a surprisingly close correlation was found. With the exception of Lipomyces starkeyi, all the organisms which were deoxyribonuclease-negative were also urease-negative. Of those organisms which were deoxyribonuclease-positive, only E. fibuligera was urease-negative. The ability of cryptococci to produce extracellular deoxyribonuclease is discussed in relation to the implication which this finding may have for the taxonomy and phylogeny of the genus. PMID:5354946

Cazin, John; Kozel, Thomas R.; Lupan, David M.; Burt, Wayne R.

1969-01-01

122

Extracellular deoxyribonuclease production by yeasts.  

PubMed

A total of 20 genera of yeasts and yeastlike organisms were tested for their ability to produce an extracellular deoxyribonuclease. Results indicate that ability to produce the enzyme appears to be a specific characteristic of the three genera Rhodotorula, Cryptococcus, and Tremella. A single strain of Endomycopsis fibuligera was also shown to be positive for the enzyme. In comparing the ability of the organisms to excrete extracellular deoxyribonuclease with their ability to produce urease, a surprisingly close correlation was found. With the exception of Lipomyces starkeyi, all the organisms which were deoxyribonuclease-negative were also urease-negative. Of those organisms which were deoxyribonuclease-positive, only E. fibuligera was urease-negative. The ability of cryptococci to produce extracellular deoxyribonuclease is discussed in relation to the implication which this finding may have for the taxonomy and phylogeny of the genus. PMID:5354946

Cazin, J; Kozel, T R; Lupan, D M; Burt, W R

1969-11-01

123

Biology of the pathogenic yeast Candida glabrata.  

PubMed

The yeasts, being favorite eukaryotic microorganisms used in food industry and biotechnologies for production of biomass and various substances, are also used as model organisms in genetic manipulation, molecular and biological research. In this respect, Saccharomyces cerevisiae is the best-known species but current situation in medicine and industry requires the use of other species. Here we summarize the basic taxonomic, morphological, physiological, genetic, etc. information about the pathogenic yeast Candida glabrata that is evolutionarily very closely related to baker's yeast. PMID:16821705

Bialková, A; Subík, J

2006-01-01

124

Corning and Kroger turn whey to yeast  

SciTech Connect

It is reported that Corning and Kroger intend to build a 35,000 sq. ft. plant in Winchester, Ky., that will turn whey into bakers' yeast. The plant will convert whey from Kroger's dairies into bakers' yeast, supplying about 60% of the yeast needed for nine Kroger bakeries. It will also produce syrups and whey protein concentrate for use in other food processing activities. In addition to making useful products, the project will convert the whey to glucose and galactose. The protein component of the whey will be concentrated and used in various foods and feeds.

Not Available

1981-11-16

125

Yeast Transformation (introducing plasmid vector into a yeast strain): This protocol is a modification (shortened version) of "The BEST  

E-print Network

Yeast Transformation (introducing plasmid vector into a yeast strain): This protocol://www.umanitoba.ca/medicine/biochem/gietz/Trafo.html) 1. Inoculate 5 ml of YPD with a yeast colony from plate. 2. Grow culture overnight at 300 C. 3 and centrifuging at 1750xg (high speed in clinical centrifuge) for 2 minutes. 6. Carefully pour media off of yeast

126

Kinetochore Structure: Pulling Answers from Yeast  

E-print Network

Despite the identification of multiple kinetochore proteins, their structure and organization has remained unclear. New work uses electron microscopy to visualize isolated budding yeast kinetochore particles and reveal the ...

Cheeseman, Iain M.

127

Protection from nitrosative stress by yeast flavohemoglobin  

PubMed Central

Yeast hemoglobin was discovered close to half a century ago, but its function has remained unknown. Herein, we report that this flavohemoglobin protects Saccharomyces cerevisiae from nitrosative stress. Deletion of the flavohemoglobin gene (YHB1) abolished the nitric oxide (NO)-consuming activity of yeast cells. Levels of protein nitrosylation were more than 10-fold higher in yhb1 mutant yeast than in isogenic wild-type cells after incubation with NO donors. Growth of mutant cells was inhibited by a nitrosative challenge that had little effect on wild-type cells, whereas the resistance of mutant cells to oxidative stress was unimpaired. Protection conferred by yeast flavohemoglobin against NO and S-nitrosothiols was seen under both anaerobic and aerobic conditions, consistent with a primary function in NO detoxification. A phylogenetic analysis indicated that protection from nitrosative stress is likely to be a conserved function among microorganismal flavohemoglobins. Flavohemoglobin is therefore a potential target for antimicrobial therapy. PMID:10758168

Liu, Limin; Zeng, Ming; Hausladen, Alfred; Heitman, Joseph; Stamler, Jonathan S.

2000-01-01

128

Prion formation by a yeast GLFG nucleoporin  

E-print Network

The self-assembly of proteins into higher order structures is both central to normal biology and a dominant force in disease. Certain glutamine/asparagine (Q/N)-rich proteins in the budding yeast Saccharomyces cerevisiae ...

Halfmann, Randal

129

Comparative Functional Genomics of the Fission Yeasts  

E-print Network

The fission yeast clade—comprising Schizosaccharomyces pombe, S. octosporus, S. cryophilus, and S. japonicus—occupies the basal branch of Ascomycete fungi and is an important model of eukaryote biology. A comparative ...

Regev, Aviv

130

Mitochondria, metabolism, and aging in yeast  

Microsoft Academic Search

\\u000a Quantitative and qualitative changes in metabolism take place when the lifespan is extended in yeast either by genetic or\\u000a nutritional manipulation. In particular, remodeling of mitochondrial function occurs, and the relationship between this organelle\\u000a and other cellular compartments moves to the fore. Two separate pathways, the retrograde response and calorie restriction,\\u000a operate as metabolic mechanisms for life extension in yeast.

S. Michal Jazwinski

131

Yeast flocculation: what brewers should know  

Microsoft Academic Search

For many industrial applications in which the yeast Saccharomyces cerevisiae is used, e.g. beer, wine and alcohol production, appropriate flocculation behaviour is certainly one of the most important characteristics of a good production strain. Yeast flocculation is a very complex process that depends on the expression of specific flocculation genes such as FLO1, FLO5, FLO8 and FLO11. The transcriptional activity

K. J. Verstrepen; G. Derdelinckx; H. Verachtert; F. R. Delvaux

2003-01-01

132

Cooperative regulation in yeast cell cycle network  

E-print Network

We define a measure of cooperativity for gene regulatory networks which we propose should be maximized under a demand for energy efficiency. We investigate its dependence on network size, connectivity and the fraction of repressory/activatory interactions. Next, we consider the cell-cycle regulatory network of the yeast, Saccharomyces cerevisiae, as a case study and calculate its degree of cooperativity. A comparison with random networks of similar size and composition reveals that the yeast's cell-cycle regulation is exceptionally cooperative.

Nese Aral; Alkan Kabakcioglu

2014-06-28

133

[Yeasts--biosorbents of heavy metals].  

PubMed

The sharp increase of the level of environment pollution by heavy metals caused the increase of interest to the problem of live organisms (including microorganisms) resistance to these metals. Biosorption is one of the mechanisms of microorganisms resistance to heavy metals. Yeasts as biosorbents are of special interest. An analysis of the data from literature have shown that the yeast biomass may be used successfully as biosorption material for such metals as Ag, Au, Cd, Co, Cr, Cu, Ni, Pb, U, Th, Zn. Yeasts of genera Saccharomyces, Candida, Pichia are efficient biosorbents of metals. The sorptional system estimation is based on the classic sorption isotherm obtained in the course of equilibrium experiments and depends on pH, properties of metal ions, biomass concentration, preliminary physical or chemical treatment of the biomass, presence of various organic and inorganic ions and on temperature. The yeast biomass may be obtained using numerous industrial processes, that decreases considerably the biosorbent cost. Most yeasts can sorb a wide range of metals or be strictly specific in respect of only one metal. Special attention would be paid to the cell wall which structure determines sorption proceeding mechanisms. Problems of mechanisms of heavy metal biosorption by microorganisms at molecular level are discussed. The review also deals with the newest developments on improving the biosorption processes in microorganisms, yeast in particular. PMID:15104060

Podgorski?, V S; Kasatkina, T P; Lozovaia, O G

2004-01-01

134

The one hour yeast proteome.  

PubMed

We describe the comprehensive analysis of the yeast proteome in just over one hour of optimized analysis. We achieve this expedited proteome characterization with improved sample preparation, chromatographic separations, and by using a new Orbitrap hybrid mass spectrometer equipped with a mass filter, a collision cell, a high-field Orbitrap analyzer, and, finally, a dual cell linear ion trap analyzer (Q-OT-qIT, Orbitrap Fusion). This system offers high MS(2) acquisition speed of 20 Hz and detects up to 19 peptide sequences within a single second of operation. Over a 1.3 h chromatographic method, the Q-OT-qIT hybrid collected an average of 13,447 MS(1) and 80,460 MS(2) scans (per run) to produce 43,400 (x) peptide spectral matches and 34,255 (x) peptides with unique amino acid sequences (1% false discovery rate (FDR)). On average, each one hour analysis achieved detection of 3,977 proteins (1% FDR). We conclude that further improvements in mass spectrometer scan rate could render comprehensive analysis of the human proteome within a few hours. PMID:24143002

Hebert, Alexander S; Richards, Alicia L; Bailey, Derek J; Ulbrich, Arne; Coughlin, Emma E; Westphall, Michael S; Coon, Joshua J

2014-01-01

135

Glycogenolytic enzymes in sporulating yeast.  

PubMed Central

During meiosis in Saccharomyces cerevisiae, the polysaccharide glycogen is first synthesized and then degraded during the period of spore maturation. We have detected, in sporulating yeast strains, an enzyme activity which is responsible for the glycogen catabolism. The activity was absent in vegetative cells, appeared coincidently with the beginning of glycogenolysis and the appearance of mature ascospores, and increased progressively until spourlation was complete. The specific activity of glycogenolytic enzymes in the intact ascus was about threefold higher than in isolated spores. The glycogenolysis was not due to combinations of phosphorylase plus phosphatase or amylase plus maltase. Nonsporulating cells exhibited litle or no glycogen catabolism and contained only traces of glycogenolytic enzyme, suggesting that the activity is sporulation specific. The partially purified enzyme preparation degraded amylose and glycogen, releasing glucose as the only low-molecular-weight product. Maltotriose was rapidly hydrolyzed; maltose was less susceptible. Alpha-methyl-D-glucoside, isomaltose, and linear alpha-1,6-linked dextran were not attacked. However, the enzyme hydrolyzed alpha-1,6-glucosyl-Schardinger dextrin and increased the beta-amylolysis of beta-amylase-limit dextrin. Thus, the preparation contains alpha-1,4- and alpha-1,6-glucosidase activities. Sephadex G-150 chromatography partially resolved the enzyme into two activities, one of which may be a glucamylase and the other a debranching enzyme. Images PMID:350852

Colonna, W J; Magee, P T

1978-01-01

136

Boolean Model of Yeast Apoptosis as a Tool to Study Yeast and Human Apoptotic Regulations  

PubMed Central

Programmed cell death (PCD) is an essential cellular mechanism that is evolutionary conserved, mediated through various pathways and acts by integrating different stimuli. Many diseases such as neurodegenerative diseases and cancers are found to be caused by, or associated with, regulations in the cell death pathways. Yeast Saccharomyces cerevisiae, is a unicellular eukaryotic organism that shares with human cells components and pathways of the PCD and is therefore used as a model organism. Boolean modeling is becoming promising approach to capture qualitative behavior and describe essential properties of such complex networks. Here we present large literature-based and to our knowledge first Boolean model that combines pathways leading to apoptosis (a type of PCD) in yeast. Analysis of the yeast model confirmed experimental findings of anti-apoptotic role of Bir1p and pro-apoptotic role of Stm1p and revealed activation of the stress protein kinase Hog proposing the maximal level of activation upon heat stress. In addition we extended the yeast model and created an in silico humanized yeast in which human pro- and anti-apoptotic regulators Bcl-2 family and Valosin-contain protein (VCP) are included in the model. We showed that accumulation of Bax in silico humanized yeast shows apoptotic markers and that VCP is essential target of Akt Signaling. The presented Boolean model provides comprehensive description of yeast apoptosis network behavior. Extended model of humanized yeast gives new insights of how complex human disease like neurodegeneration can initially be tested. PMID:23233838

Kazemzadeh, Laleh; Cvijovic, Marija; Petranovic, Dina

2012-01-01

137

Boolean model of yeast apoptosis as a tool to study yeast and human apoptotic regulations.  

PubMed

Programmed cell death (PCD) is an essential cellular mechanism that is evolutionary conserved, mediated through various pathways and acts by integrating different stimuli. Many diseases such as neurodegenerative diseases and cancers are found to be caused by, or associated with, regulations in the cell death pathways. Yeast Saccharomyces cerevisiae, is a unicellular eukaryotic organism that shares with human cells components and pathways of the PCD and is therefore used as a model organism. Boolean modeling is becoming promising approach to capture qualitative behavior and describe essential properties of such complex networks. Here we present large literature-based and to our knowledge first Boolean model that combines pathways leading to apoptosis (a type of PCD) in yeast. Analysis of the yeast model confirmed experimental findings of anti-apoptotic role of Bir1p and pro-apoptotic role of Stm1p and revealed activation of the stress protein kinase Hog proposing the maximal level of activation upon heat stress. In addition we extended the yeast model and created an in silico humanized yeast in which human pro- and anti-apoptotic regulators Bcl-2 family and Valosin-contain protein (VCP) are included in the model. We showed that accumulation of Bax in silico humanized yeast shows apoptotic markers and that VCP is essential target of Akt Signaling. The presented Boolean model provides comprehensive description of yeast apoptosis network behavior. Extended model of humanized yeast gives new insights of how complex human disease like neurodegeneration can initially be tested. PMID:23233838

Kazemzadeh, Laleh; Cvijovic, Marija; Petranovic, Dina

2012-01-01

138

Inhibition of spoilage yeasts in cheese by killer yeast Williopsis saturnus var. saturnus.  

PubMed

Williopsis saturnus var. saturnus is a known killer toxin-producing yeast. The effects of this yeast as a biopreservative against spoilage yeasts (galactose fermenting) were investigated in cheeses made under laboratory conditions. At an inoculation level of approximately 10(6) CFU/g of cheese, this killer yeast inhibited growth of lactose non-fermenting but galactose-fermenting yeast Saccharomyces cerevisiae VL1 inoculated at approximately 10(3) CFU/g; it also inhibited growth of lactose-fermenting and galactose-fermenting yeast Kluvyveromyces marxianus ATCC8640 inoculated at approximately 10(3)-10(4) CFU/g in the cheeses manufactured with galactose-producing starter culture Streptococcus thermophilus. In contrast, the two spoilage yeasts grew to approximately 10(6) CFU/g from the initial cell count of approximately 10(3) CFU/g without the killer yeast. This study indicated that W. saturnus var. saturnus could be an effective biopreservative for cheese spoilage control. PMID:19349088

Liu, Shao-Quan; Tsao, Marlene

2009-05-31

139

Selection in yeast I: Assessing genetic stability and relative fitness of commercial yeasts  

Microsoft Academic Search

Summary The potential for changes in allele frequencies in yeast populations by selection was examined. Cells from the wine yeastSaccharomyces cerevisiae (strain Montrachet) were grown over a large number of generations using two different culturing techniques, each with two variations: serial transfers on WLN agar plates with and without UV irradiation, and continuous culture in autoclaved and in filter-sterilized grape

Ronald E. Subden; Robert L. Charlebois; C. Kenneth Carey

1987-01-01

140

Mitochondrial membrane lipidome defines yeast longevity.  

PubMed

Our studies revealed that lithocholic acid (LCA), a bile acid, is a potent anti-aging natural compound that in yeast cultured under longevity-extending caloric restriction (CR) conditions acts in synergy with CR to enable a significant further increase in chronological lifespan. Here, we investigate a mechanism underlying this robust longevity-extending effect of LCA under CR. We found that exogenously added LCA enters yeast cells, is sorted to mitochondria, resides mainly in the inner mitochondrial membrane, and also associates with the outer mitochondrial membrane. LCA elicits an age-related remodeling of glycerophospholipid synthesis and movement within both mitochondrial membranes, thereby causing substantial changes in mitochondrial membrane lipidome and triggering major changes in mitochondrial size, number and morphology. In synergy, these changes in the membrane lipidome and morphology of mitochondria alter the age-related chronology of mitochondrial respiration, membrane potential, ATP synthesis and reactive oxygen species homeostasis. The LCA-driven alterations in the age-related dynamics of these vital mitochondrial processes extend yeast longevity. In sum, our findings suggest a mechanism underlying the ability of LCA to delay chronological aging in yeast by accumulating in both mitochondrial membranes and altering their glycerophospholipid compositions. We concluded that mitochondrial membrane lipidome plays an essential role in defining yeast longevity. PMID:23924582

Beach, Adam; Richard, Vincent R; Leonov, Anna; Burstein, Michelle T; Bourque, Simon D; Koupaki, Olivia; Juneau, Mylène; Feldman, Rachel; Iouk, Tatiana; Titorenko, Vladimir I

2013-07-01

141

A study of ethanol tolerance in yeast.  

PubMed

The ethanol tolerance of yeast and other microorganisms has remained a controversial area despite the many years of study. The complex inhibition mechanism of ethanol and the lack of a universally accepted definition and method to measure ethanol tolerance have been prime reasons for the controversy. A number of factors such as plasma membrane composition, media composition, mode of substrate feeding, osmotic pressure, temperature, intracellular ethanol accumulation, and byproduct formation have been shown to influence the ethanol tolerance of yeast. Media composition was found to have a profound effect upon the ability of a yeast strain to ferment concentrated substrates (high osmotic pressure) and to ferment at higher temperatures. Supplementation with peptone-yeast extract, magnesium, or potassium salts has a significant and positive effect upon overall fermentation rates. An intracellular accumulation of ethanol was observed during the early stages of fermentation. As fermentation proceeds, the intracellular and extracellular ethanol concentrations become similar. In addition, increases in osmotic pressure are associated with increased intracellular accumulation of ethanol. However, it was observed that nutrient limitation, not increased intracellular accumulation of ethanol, is responsible to some extent for the decreases in growth and fermentation activity of yeast cells at higher osmotic pressure and temperature. PMID:2178780

D'Amore, T; Panchal, C J; Russell, I; Stewart, G G

1990-01-01

142

Influence of pesticides on yeasts colonizing leaves.  

PubMed

The effect of nine different pesticides on the growth of yeasts isolated from the leaves of fruit and forest trees was investigated. Four insecticides (with the active ingredients: thiacloprid, deltamethrin, lambdacyhalothrin, and thiamethoxam) and five fungicides (with the effective substances: bitertanol, kresoxim-methyl, mancozeb, trifloxystrobin, and cupric oxychloride) were tested. The concentrations of chemicals were those recommended by the manufacturers for the spraying of trees. The yeast strains isolated from the leaves of fruit trees were not sensitive to any of the insecticides. The majority of yeast strains isolated from the leaves of forest trees were either not sensitive or only to a small extent. While Rhodotorula mucilaginosa and Pichia anomala were not affected by any insecticide, the strains of Cryptococcus laurentii and Rhodotorula glutinis showed the highest sensitivity. The effects of fungicides on the growth of isolated yeasts were more substantial. The fungicide Dithane DG (mancozeb) completely inhibited the growth of all yeasts. All strains isolated from fruit tree leaves were more resistant to the tested fungicides than those isolated from the leaves of forest trees. The most resistant strains from the leaves of fruit trees belonged to the species Metschnikowia pulcherrima, Pichia anomala, and Saccharomyces cerevisiae, whereas Cryptococcus albidus and C. laurentii, originating from the leaves of forest trees, showed the highest sensitivity to fungicides. PMID:22351984

Vadkertiová, Renata; Sláviková, Elena

2011-01-01

143

Ecology of pathogenic yeasts in Amazonian soil.  

PubMed Central

In an investigation of Amazonian soil as a natural reservoir for pathogenic fungi, 1,949 soil samples collected from diverse geographical and ecological settings of the Brazilian Amazon Basin were analyzed for the presence of non-keratinophilic fungi by the indirect mouse inoculation procedure and for the presence of keratinophilic fungi by the hair bait technique. All soil samples were acidic with low pH values. From 12% of the soil samples, 241 yeast and yeastlike isolates pertaining to six genera and 82 species were recovered, of which 63% were Torulopsis and 26% were Candida species. Nine fungi with known pathogenic potentials were encountered among 43% (104) of the isolates: T. glabrata, C. guilliermondii, C. albicans, C. pseudotropicalis, C. stellatoidea, C. tropicalis, Rhodotorula rubra, and Wangiella dermatitidis. The yeast flora was marked by species diversity, low frequency of each species, random geographical distribution, and an apparent lack of species clustering. The composition and distribution of the yeast flora in soil differed from those of the yeast flora harbored by bats, suggesting that the Amazonian external environment and internal bat organs act as independent natural habitats for yeasts. PMID:6538774

Mok, W Y; Luizao, R C; do Socorro Barreto da Silva, M; Teixeira, M F; Muniz, E G

1984-01-01

144

The organization of oligonucleosomes in yeast.  

PubMed Central

We have developed a method of preparing yeast chromatin that facilitates the analysis of nucleoprotein organization. Yeast chromatin, isolated as an insoluble complex, is digested with micrococcal nuclease and fractionated into major insoluble and soluble fractions. No nucleosomal repeat is seen early in digestion for the insoluble fraction. Nucleosomal complexes of the soluble fraction are excised by nuclease in a distinctive non-random pattern; they are markedly depleted in mononucleosomes. When we analyze the soluble material by high resolution native electrophoresis, we find that the nucleoproteins resolve into two bands for each DNA multimer of the nucleosomal repeat. Our results suggest that there are structural similarities between bulk yeast chromatin and chromatin configurations found in transcribing genes of complex eukaryotes. Images PMID:6344013

Szent-Gyorgyi, C; Isenberg, I

1983-01-01

145

Biofuels. Altered sterol composition renders yeast thermotolerant.  

PubMed

Ethanol production for use as a biofuel is mainly achieved through simultaneous saccharification and fermentation by yeast. Operating at ?40°C would be beneficial in terms of increasing efficiency of the process and reducing costs, but yeast does not grow efficiently at those temperatures. We used adaptive laboratory evolution to select yeast strains with improved growth and ethanol production at ?40°C. Sequencing of the whole genome, genome-wide gene expression, and metabolic-flux analyses revealed a change in sterol composition, from ergosterol to fecosterol, caused by mutations in the C-5 sterol desaturase gene, and increased expression of genes involved in sterol biosynthesis. Additionally, large chromosome III rearrangements and mutations in genes associated with DNA damage and respiration were found, but contributed less to the thermotolerant phenotype. PMID:25278608

Caspeta, Luis; Chen, Yun; Ghiaci, Payam; Feizi, Amir; Buskov, Steen; Hallström, Björn M; Petranovic, Dina; Nielsen, Jens

2014-10-01

146

Cytotoxic Mechanism of Selenomethionine in Yeast*  

PubMed Central

Although selenium is an essential element, its excessive uptake is detrimental to living organisms. The significance of selenium for living organisms has been exploited for various purposes. However, the molecular basis of selenium toxicity is not completely understood. Here, we applied a capillary electrophoresis time-of-flight mass spectrometry-based metabolomics approach to analysis of yeast cells treated with selenomethionine. The data indicated that intracellular thiol compounds are significantly decreased, and diselenide and selenosulfide compounds are increased in selenomethionine-treated cells. The growth defect induced by selenomethionine was recovered by extracellular addition of cysteine and by genetic modification of yeast cells that have an additional de novo synthetic pathway for cysteine. Because cysteine is an intermediate of thiol compounds, these results suggested that the loss of a reduced form of thiol compounds due to selenomethionine causes a growth defect of yeast cells. PMID:22311978

Kitajima, Toshihiko; Jigami, Yoshifumi; Chiba, Yasunori

2012-01-01

147

[Molecular taxonomy techniques used for yeast identification].  

PubMed

Due to the major impact of yeasts in human life based on the existence of pathogen yeast species and of species with biotechnological abilities, in the last few years new molecular techniques are performed for an accurate identification of natural isolates. Our study is aimed to review some of these techniques such as electrokariotyping by PFGE (Pulsed Field Gel Electrophoresis), estimation of the molar percentage of guanine and cytosine, the applications of PCR reaction in yeast identification using RAPD (Random amplified polymorphic DNA), UP-PCR (Universally Primed Polymerase Chain Reaction), MLST (Multilocus sequence typing) techniques, mtDNA and rDNA homology studies. Such molecular techniques complete the phenotypical characterization based on classical taxonomical tests allowing thus the polyphasic identification of the microorganisms. PMID:16938931

Ghindea, Raluca; Csutak, Ortansa; Stoica, Ileana; Ionescu, Robertina; Soare, Simona; Pelinescu, Diana; Nohit, Ana-Maria; Creang?, Oana; Vassu, Tatiana

2004-01-01

148

Metabolic cycling without cell division cycling in respiring yeast  

E-print Network

Despite rapid progress in characterizing the yeast metabolic cycle, its connection to the cell division cycle (CDC) has remained unclear. We discovered that a prototrophic batch culture of budding yeast, growing in a ...

Slavov, Nikolai G.

149

21 CFR 172.381 - Vitamin D2 bakers yeast.  

...prescribed conditions: (a) Vitamin D2 bakers yeast is the substance produced by exposing bakers yeast (Saccharomyces cerevisiae ) to ultraviolet light, resulting in the photochemical conversion of endogenous ergosterol in bakers...

2014-04-01

150

Original article Chromium yeast affects growth performance but not  

E-print Network

Original article Chromium yeast affects growth performance but not whole carcass composition the effects of supplemented trivalent chromium (Cr) from chromium yeast on growth performance, carcass vs. ad libitum in other reported experiments). (© Elsevier / Inra) chromium / pig / carcass

Paris-Sud XI, Université de

151

RESEARCH ARTICLE Open Access Histone modification pattern evolution after yeast  

E-print Network

RESEARCH ARTICLE Open Access Histone modification pattern evolution after yeast gene duplication for evolutionary innovations. Many studies evidenced that genetic regulatory network evolved rapidly shortly after gene duplication. In this study, we conducted detailed analyses on yeast histone modification (HM

Gu, Xun

152

[The yeast biofilm in human medicine].  

PubMed

In recent years, the role of Candida yeasts as causative agents of nosocomial infections has increased. One of the important virulence factors contributing to the development of such infections is biofilm production. This virulence factor enables yeast to colonize both native surfaces and artificial implants. The most common sources of infection are patients themselves, in particular the gastrointestinal tract and skin. The vectors of exogenous yeast infections are predominantly the hands of the health personnel and contaminated medical instruments. The adhesion of yeasts to the implant surfaces is determined both by implant surface and yeast characteristics. This is followed by proliferation and production of microcolonies and extracellular matrix. The final biofilm structure is also influenced by the production of hyphae and pseudohyphae. The entire process of biofilm production is controlled by numerous regulatory systems, with the key role being played by the quorum sensing system. Like the adhered bacterial cultures, candidas growing in the form of a biofilm are highly resistant to antimicrobial therapy. Resistance of yeast biofilms to antifungals is a complex process with multiple contributing factors. These are especially increased gene expression (e.g. genes encoding the so called multidrug efflux pumps), limited penetration of substances through the extracellular matrix, inhibited cell growth and altered microenvironment in deeper biofilm layers. The concentrations of antifungals able to effectively affect the biofilm cells exceed, by several orders of magnitude, the values of conventionally determined MICs. High biofilm resistance results in ineffective antifungal therapy of biofilm infections. Therefore, if possible, the colonized implant should be removed. Conservative therapy should involve antifungals with a proven effect on the biofilm (e.g. caspofungin). The most effective measure in fighting biofilm infections is prevention, especially adhering to aseptic techniques when manipulating with implants and their correct maintenance. PMID:17929219

R?zicka, Filip; Holá, Veronika; Votava, Miroslav

2007-08-01

153

[Effect of stress on the composition of yeast lipids].  

PubMed

Pigmented (Rhodotorula glutinis) and nonpigmented (Lipomyces starkeyi) yeasts were studied. Exogenous stressors (UV irradiation and methylene blue) were shown to change the composition of yeast lipids (especially the ratio of unsaturated fatty acids) and to increase the content of lipid peroxidation products formed (particularly in nonpigmented yeasts). In carotene-synthesizing yeasts, these stressors decreased the amount of carotenoids produced and did not affect the ratio between carotenoid pigments (beta-carotene, torulene, and torularhodin). PMID:10752082

Zalashko, M V; Salokhina, G A; Koroleva, I F

2000-01-01

154

[Growth of epiphytic and soil yeasts on wheat seedlings].  

PubMed

Colonization of wheat seedlings by epiphytic (Rhodotorula glutinis) and soil (Lipomyces starkeyi) yeasts was studied by scanning electron microscopy. Epiphytic yeast cells dominated on the plant surface. Soil yeast cells were randomly distributed among both the zones of a seedling and the particles of an inorganic substrate. It has been found that epiphytic yeast strains can readily grow on the surface of a plant. PMID:561879

Guzeva, I S; Guzev, V S; Bab'eva, I P; Zviagintsev, D G

1977-01-01

155

Effects of stress on the composition of yeast lipids  

Microsoft Academic Search

Pigmented(Rhodotorula glutinis) and nonpigmented(Lipomyces starkeyi) yeasts were studied. Exogenous Stressors (UV irradiation and methylene blue) were shown to change the composition of yeast\\u000a lipids (especially the ratio of unsaturated fatty acids) and to increase the content of lipid peroxidation products formed\\u000a (particularly in nonpigmented yeasts). In carotene-synthesizing yeasts, these Stressors decreased the amount of carotenoids\\u000a produced and did not affect

M. V. Zalashko; G. A. Salokhina; I. F. Koroleva

2000-01-01

156

Construction of an efficient amylolytic industrial yeast strain containing DNA exclusively derived from yeast.  

PubMed

An amylolytic industrial yeast strain of Saccharomyces cerevisiae containing the Schwanniomyces occidentalis SWA2 amylase gene was generated. The new strain contains DNA derived exclusively from yeast and expresses a high starch hydrolyzing activity. Yeast transformation was carried out by an integrative process targeted to a dispensable upstream region of the ILV2 locus, which determines sulfometuron resistance. The SWA2 enzyme was constitutively expressed under the ADH1 promoter. The growth, substrate utilization and fermentative capacity of this organism are described. PMID:11470369

Marín, D; Jiménez, A; Fernández Lobato, M

2001-07-24

157

Mitochondrial network size scaling in budding yeast.  

PubMed

Mitochondria must grow with the growing cell to ensure proper cellular physiology and inheritance upon division. We measured the physical size of mitochondrial networks in budding yeast and found that mitochondrial network size increased with increasing cell size and that this scaling relation occurred primarily in the bud. The mitochondria-to-cell size ratio continually decreased in aging mothers over successive generations. However, regardless of the mother's age or mitochondrial content, all buds attained the same average ratio. Thus, yeast populations achieve a stable scaling relation between mitochondrial content and cell size despite asymmetry in inheritance. PMID:23139336

Rafelski, Susanne M; Viana, Matheus P; Zhang, Yi; Chan, Yee-Hung M; Thorn, Kurt S; Yam, Phoebe; Fung, Jennifer C; Li, Hao; Costa, Luciano da F; Marshall, Wallace F

2012-11-01

158

Mitochondrial Network Size Scaling in Budding Yeast**  

PubMed Central

Mitochondria must grow with the growing cell to ensure proper cellular physiology and inheritance upon division. We measured the physical size of mitochondrial networks in budding yeast and found that mitochondrial network size increased with increasing cell size and that this scaling relation occurred primarily in the bud. The mitochondria to cell size ratio continually decreased in aging mothers over successive generations. However, regardless of mother age or mitochondrial content, all buds attained the same average ratio. Thus, yeast populations achieve a stable scaling relation between mitochondrial content and cell size despite asymmetry in inheritance. PMID:23139336

Rafelski, Susanne M.; Viana, Matheus P.; Zhang, Yi; Chan, Yee-Hung M.; Thorn, Kurt S.; Yam, Phoebe; Fung, Jennifer C.; Li, Hao; Costa, Luciano da F.; Marshall, Wallace F.

2013-01-01

159

Principles of chromosomal organization: lessons from yeast  

PubMed Central

The spatial organization of genes and chromosomes plays an important role in the regulation of several DNA processes. However, the principles and forces underlying this nonrandom organization are mostly unknown. Despite its small dimension, and thanks to new imaging and biochemical techniques, studies of the budding yeast nucleus have led to significant insights into chromosome arrangement and dynamics. The dynamic organization of the yeast genome during interphase argues for both the physical properties of the chromatin fiber and specific molecular interactions as drivers of nuclear order. PMID:21383075

Zimmer, Christophe

2011-01-01

160

Yeast identification in floral nectar of Mimulus aurantiacus (Invited)  

Microsoft Academic Search

Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in

C. Kyauk; M. Belisle; T. Fukami

2009-01-01

161

21 CFR 172.590 - Yeast-malt sprout extract.  

... 3 2014-04-01 2014-04-01 false Yeast-malt sprout extract. 172.590 Section 172...Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this...

2014-04-01

162

Boolean Network Model Predicts Cell Cycle Sequence of Fission Yeast  

E-print Network

Boolean Network Model Predicts Cell Cycle Sequence of Fission Yeast Maria I. Davidich, Stefan network model of the cell-cycle regulatory network of fission yeast (Schizosaccharomyces Pombe sequence being a strongly attractive trajectory. Comparing the fission yeast cell-cycle model to a similar

Bornholdt, Stefan

163

Research Focus A short history of recombination in yeast  

E-print Network

Research Focus A short history of recombination in yeast Clifford W. Zeyl1* and Sarah P. Otto2* 1 of fungal genomics, we know little about either the ecology or reproductive biology of the budding yeast of a studyofhistoricalpoutcrossingeventsand inferthe genomic positions of previous recombination events in the yeast Saccharomyces cerevisiae

Otto, Sarah

164

Robust Spatial Sensing of Mating Pheromone Gradients by Yeast Cells  

E-print Network

Robust Spatial Sensing of Mating Pheromone Gradients by Yeast Cells Travis I. Moore1,2 , Ching not degrade the pheromone input. The yeast cells exhibited good accuracy with the mating projection typically caused defects in both sensing and response. Interestingly, yeast cells employed adaptive mechanisms

Nie, Qing

165

Clustering, Communication and Environmental Oscillations in Populations of Budding Yeast  

E-print Network

Clustering, Communication and Environmental Oscillations in Populations of Budding Yeast Chris describe how simple models of communication, consistent with known yeast phys- iological mechanisms relevant variables during yeast growth and division have been reported and studied for over 40 years [8, 12

Young, Todd

166

Yeast Genes That Enhance the Toxicity of a Mutant Huntingtin  

E-print Network

Yeast Genes That Enhance the Toxicity of a Mutant Huntingtin Fragment or -Synuclein Stephen-wide screens were performed in yeast to identify genes that enhance the toxicity of a mutant huntingtin's yeast Sac- charomyces cerevisiae as a model eukaryotic organism to test the hypothesis that the down

Lindquist, Susan

167

Exploring the Yeast Genome with Generalized Singular Value  

E-print Network

Exploring the Yeast Genome with Generalized Singular Value Decomposition Andrew Ferguson Advisor courses of the yeast Saccharomyces cerevisiae under two different experimental con- ditions. In the first analysis, a comparison is performed between the yeast stress response to hydrogen peroxide (H2O2

Fonseca, Rodrigo

168

INVESTIGATION Natural Variation in the Yeast Glucose-Signaling  

E-print Network

of respiration, is a hallmark of budding yeast's glucose response and a model for the Warburg effect in humanINVESTIGATION Natural Variation in the Yeast Glucose-Signaling Network Reveals a New Role uncovered, despite numerous investigations of laboratory yeast strains. Here we studied a wild isolate

Gasch, Audrey P.

169

Global Gene Expression Analysis of Yeast Cells during Sake Brewing  

Microsoft Academic Search

During the process of brewing Japanese sake, rice starch is saccharified by enzymes produced by koji (Aspergillus oryzae), and the resultant glucose is fermented to ethanol by sake yeast (Saccharomyces cerevisiae). This process allows a highly con- densed mash to be made without accumulation of high levels of sugars, which inhibit yeast cell growth and ethanol fermenta- tion. Thus, yeast

Hong Wu; Xiaohong Zheng; Yoshio Araki; Hiroshi Sahara; Hiroshi Takagi; Hitoshi Shimoi

2006-01-01

170

New insights into treating Parkinson's from yeast, stem cell experiments  

E-print Network

problems of Parkinson's disease may seem tenuous at best, the researchers engineered the yeast for compounds that were able to reverse the problems when administered to the yeast. A number of compounds@globe.com. Follow her on Twitter @carolynyjohnson. New insights into treating Parkinson's from yeast, stem cell exp

Sabatini, David M.

171

Gene Expression in Yeast. Helsinki 1983, ed. by M.  

E-print Network

of the Alko Yeast Symposium Korhola & E. Viiisiinen, Foundation for Fermentation Research I (1983): 19Gene Expression in Yeast. Helsinki 1983, ed. by M. Biotechnical and Industrial Proceedings-29. A RELATIONSHIP BETI^IEENCHROMATIN STRUCTUREAND GENETIC ELEMENTS AT THE YEAST HIS3 LOCUS Department of Biological

172

Production of lipid compounds in the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

This review describes progress using the yeast Saccharomyces cerevisiae as a model organism for the fast and efficient analysis of genes and enzyme activities involved in the lipid biosynthetic pathways of several donor organisms. Furthermore, we assess the impact of baker's yeast on the production of novel, high-value lipid compounds. Yeast can be genetically modified to produce selected substances in

M. Veen; C. Lang

2004-01-01

173

Schizosaccharomyces japonicus: the fission yeast is a fusion of yeast and hyphae.  

PubMed

The clade of Schizosaccharomyces includes 4 species: S. pombe, S. octosporus, S. cryophilus, and S. japonicus. Although all 4 species exhibit unicellular growth with a binary fission mode of cell division, S. japonicus alone is dimorphic yeast, which can transit from unicellular yeast to long filamentous hyphae. Recently it was found that the hyphal cells response to light and then synchronously activate cytokinesis of hyphae. In addition to hyphal growth, S. japonicas has many properties that aren't shared with other fission yeast. Mitosis of S. japonicas is referred to as semi-open mitosis because dynamics of nuclear membrane is an intermediate mode between open mitosis and closed mitosis. Novel genetic tools and the whole genomic sequencing of S. japonicas now provide us with an opportunity for revealing unique characters of the dimorphic yeast. PMID:24375690

Niki, Hironori

2014-03-01

174

Dynamic changes in brewing yeast cells in culture revealed by statistical analyses of yeast morphological data.  

PubMed

The vitality of brewing yeasts has been used to monitor their physiological state during fermentation. To investigate the fermentation process, we used the image processing software, CalMorph, which generates morphological data on yeast mother cells and bud shape, nuclear shape and location, and actin distribution. We found that 248 parameters changed significantly during fermentation. Successive use of principal component analysis (PCA) revealed several important features of yeast, providing insight into the dynamic changes in the yeast population. First, PCA indicated that much of the observed variability in the experiment was summarized in just two components: a change with a peak and a change over time. Second, PCA indicated the independent and important morphological features responsible for dynamic changes: budding ratio, nucleus position, neck position, and actin organization. Thus, the large amount of data provided by imaging analysis can be used to monitor the fermentation processes involved in beer and bioethanol production. PMID:24012106

Ohnuki, Shinsuke; Enomoto, Kenichi; Yoshimoto, Hiroyuki; Ohya, Yoshikazu

2014-03-01

175

Yeast Genomic DNA Prep Sterile distilled water  

E-print Network

Auble Lab Yeast Genomic DNA Prep Reagents: Sterile distilled water -mercaptoethanol Sorbitol Buffer conical tube at 3,000 rpms for 5 minutes. 3. Resuspend in 10 ml of sterile distilled (SD) water, then spin for 5 minutes at 3,000 rpms and decant off water. 4. Resuspend in 5 ml of SD water and add 100 µl

Auble, David

176

Carbon source dependent promoters in yeasts.  

PubMed

Budding yeasts are important expression hosts for the production of recombinant proteins.The choice of the right promoter is a crucial point for efficient gene expression, as most regulations take place at the transcriptional level. A wide and constantly increasing range of inducible, derepressed and constitutive promoters have been applied for gene expression in yeasts in the past; their different behaviours were a reflection of the different needs of individual processes.Within this review we summarize the majority of the large available set of carbon source dependent promoters for protein expression in yeasts, either induced or derepressed by the particular carbon source provided. We examined the most common derepressed promoters for Saccharomyces cerevisiae and other yeasts, and described carbon source inducible promoters and promoters induced by non-sugar carbon sources. A special focus is given to promoters that are activated as soon as glucose is depleted, since such promoters can be very effective and offer an uncomplicated and scalable cultivation procedure. PMID:24401081

Weinhandl, Katrin; Winkler, Margit; Glieder, Anton; Camattari, Andrea

2014-01-01

177

Cellular functions of cardiolipin in yeast  

Microsoft Academic Search

Cardiolipin (CL), the signature lipid of mitochondria, plays a critical role in mitochondrial function and biogenesis. The availability of yeast mutants blocked in CL synthesis has facilitated studies of the biological role of this lipid. Perturbation of CL synthesis leads to growth defects not only during respiratory growth but also under conditions in which respiration is not essential. CL was

Amit S. Joshi; Jingming Zhou; Vishal M. Gohil; Shuliang Chen; Miriam L. Greenberg

2009-01-01

178

6 Oxidative stress responses in yeast  

Microsoft Academic Search

Yeast, and especially S. cerevisiae, is a unique eukaryotic model organism for studying oxidative stress and its cellular responses. S. cerevisiae has become a very powerful tool to decipher the complexity of these biologically important responses, because it offers the relative simplicity of a single celled eukaryotic organism that enables the combination and integration of genetic, biochemical, physico-chemical, cell biological,

Michel B. Toledano; Agnes Delaunay; Benoit Biteau; Daniel Spector; Dulce Azevedo

179

Yeast Idiosyncrasies From Cora Styles (Fink Lab)  

E-print Network

1 Yeast Idiosyncrasies From Cora Styles (Fink Lab) ade1 and ade2 cultures turn red. The intensity parent into the + cytoplasm brought in by the other parent. See Protocol: Curing cytoplasm of +, C. Styles 1981 (Blue Protocols Notebook). Sporulation Quality and efficiency is sensitive to many factors

Aris, John P.

180

The interaction map of yeast: terra incognita?  

PubMed Central

A systematic curation of the literature on Saccharomyces cerevisiae has yielded a comprehensive collection of experimentally observed interactions. This new resource augments current views of the topological structure of yeast's physical and genetic networks, but also reveals that existing studies cover only a fraction of the cell. PMID:16762048

Mellor, Joe; DeLisi, Charles

2006-01-01

181

Genomic Mismatch Scanning in Yeast December 2005  

E-print Network

that remains is "typical" salt/DNA precipitate. 13. Dissolve each pellet in 45 µL 1xTE. Pool each set and Matt Brauer of the Botstein lab for use with USB enzymes. A. Preparation of genomic DNA from yeast (Qiagen protocol) 3-4 days from colony Large amounts of high-quality genomic DNA are critical

Dunham, Maitreya

182

Global analysis of protein phosphorylation in yeast  

Microsoft Academic Search

Protein phosphorylation is estimated to affect 30% of the proteome and is a major regulatory mechanism that controls many basic cellular processes. Until recently, our biochemical understanding of protein phosphorylation on a global scale has been extremely limited; only one half of the yeast kinases have known in vivo substrates and the phosphorylating kinase is known for less than 160

Jason Ptacek; Geeta Devgan; Gregory Michaud; Heng Zhu; Xiaowei Zhu; Joseph Fasolo; Hong Guo; Ghil Jona; Ashton Breitkreutz; Richelle Sopko; Rhonda R. McCartney; Martin C. Schmidt; Najma Rachidi; Soo-Jung Lee; Angie S. Mah; Lihao Meng; Michael J. R. Stark; David F. Stern; Claudio de Virgilio; Mike Tyers; Brenda Andrews; Mark Gerstein; Barry Schweitzer; Paul F. Predki; Michael Snyder

2005-01-01

183

Glucose-Induced Acidification in Yeast Cultures  

ERIC Educational Resources Information Center

We present an investigation (for A-level biology students and equivalent) into the mechanism of glucose-induced extracellular acidification in unbuffered yeast suspensions. The investigation is designed to enhance understanding of aspects of the A-level curriculum that relate to the phenomenon (notably glucose catabolism) and to develop key skills…

Myers, Alan; Bourn, Julia; Pool, Brynne

2005-01-01

184

Arachidonic acid metabolites in pathogenic yeasts  

PubMed Central

Although most of what is known about the biology and function of arachidonic acid metabolites comes from the study of mammalian biology, these compounds can also be produced by lower eukaryotes, including yeasts and other fungi. It is also in this group of organisms that the least is known about the metabolic pathways leading to the production of these compounds as well as the functions of these compounds in the biology of fungi and yeasts. This review will deal with the discovery of oxylipins from polyunsaturated fatty acids, and more specifically the arachidonic acid derived eicosanoids, such as 3-hydroxy eicosatetraenoic acid, prostaglandin F2? and prostaglandin E2, in yeasts starting in the early 1990s. This review will also focus on what is known about the metabolic pathways and/or proteins involved in the production of these compounds in pathogenic yeasts. The possible roles of these compounds in the biology, including the pathology, of these organisms will be discussed. PMID:22873782

2012-01-01

185

Altered transcription in yeast expressing expanded polyglutamine  

E-print Network

, and the spinocerebellar atax- ias (SCAs), are caused by expansion in the number of glutamine- encoding CAG triplet repeats are responsible for at least eight fatal neurodegenerative diseases. In mouse models, proteins with expanded diseases and provide the potential for yeast-based screens for agents that reverse polyglu- tamine toxicity

Dunham, Maitreya

186

Antarctic Yeasts: Biodiversity and Potential Applications  

NASA Astrophysics Data System (ADS)

This review is an attempt in cataloguing the diversity of yeasts in Antarctica, highlight their biotechnological potential and understand the basis of adaptation to low temperature. As of now several psychrophilic and psychrotolerant yeasts from Antarctic soils and marine waters have been characterized with respect to their growth characteristics, ecological distribution and taxonomic significance. Interestingly most of these species belonged to basidiomycetous yeasts which as a group are known for their ability to circumvent and survive under stress conditions. Simultaneously their possible role as work horses in the biotechnological industry was recognized due to their ability to produce novel enzymes and biomolecules such as agents for the breakdown of xenobiotics, and novel pharmaceutical chemi cals. The high activity of psychrophilic enzymes at low and moderate temperatures offers potential economic benefits. As of now lipases from Pseudozyma antarctica have been extensively studied to understand their unique thermal stability at 90°C and also because of its use in the pharmaceutical, agriculture, food, cosmetics and chemical industry. A few of the other enzymes which have been studied include extracellular alpha-amylase and glucoamylase from the yeast Pseudozyma antarctica (Candida antarctica), an extra-cellular protease from Cryptococcus humicola, an aspartyl proteinase from Cryptococcus humicola, a novel extracellular subtilase from Leucosporidium antarcticum, and a xylanase from Cryptococcus adeliensis

Shivaji, S.; Prasad, G. S.

187

Molecular identification of yeasts associated with traditional Egyptian dairy products.  

PubMed

This study aimed to examine the diversity and ecology of yeasts associated with traditional Egyptian dairy products employing molecular techniques in yeast identification. A total of 120 samples of fresh and stored Domiati cheese, kariesh cheese, and "Matared" cream were collected from local markets and examined. Forty yeast isolates were cultured from these samples and identified using the restriction-fragment length polymorphism (RFLPs) of 5.8S-ITS rDNA region and sequencing of the domains D1 and D2 of the 26S rRNA gene. Yeasts were identified as Issatchenkia orientalis (13 isolates), Candida albicans (4 isolates), Clavispora lusitaniae (Candida lusitaniae) (9 isolates), Kodamaea ohmeri (Pichia ohmeri) (1 isolate), Kluyveromyces marxianus (6 isolates), and Candida catenulata (7 isolates). With the exception of C. lusitaniae, the D1/D2 26S rRNA gene sequences were 100% identical for the yeast isolates within the same species. Phylogenetic reconstruction of C. lusitaniae isolates grouped them into 3 distinguished clusters. Kariesh cheese was found to be the most diverse in its yeast floras and contained the highest total yeast count compared with other examined dairy products. This was linked to the acidic pH and lower salt content of this cheese, which favor the growth and survival of yeasts in foodstuffs. Stored Domiati cheese also contained diverse yeast species involving isolates of the pathogenic yeast C. albicans. This raises the possibility of dairy products being vehicles of transmission of pathogenic yeasts. PMID:19895478

El-Sharoud, W M; Belloch, C; Peris, D; Querol, A

2009-09-01

188

Strong static magnetic field effects on yeast proliferation and distribution.  

PubMed

The present study focuses on the effects of gradient magnetic fields on the behavior of yeast, such as its proliferation and mass distribution, and evaluates the effects of magnetism on materials in the yeast culture system. Yeast, Saccharomyces cerevisiae, was incubated in a liquid medium under magnetic fields (flux density B = 14 T). When yeast in a tube was exposed to 9-14 T magnetic fields with a maximum flux density gradient of dB/dx = 94 T/m, where x is the space coordinate, the rate of yeast proliferation under the magnetic fields decreased after 16 h of incubation compared to that of the control group. The physical properties of the yeast culture system were investigated to discover the mechanism responsible for the observed deceleration in yeast proliferation under magnetic fields. Gas pressure inside the yeast culture flask was compared with and without exposure to a magnetic field. The results suggested that the gas pressure inside a flask with 6 T, 60 T/m slowly increased in comparison to the pressure inside a control tube. Due to the diamagnetism of water (medium solution) and yeast, the liquid surface distinctly inclined under gradient magnetic fields, and the hydrostatic force in suspension was strengthened by the diamagnetic forces. In addition, magnetophoresis of the yeast cells in the medium solution exhibited localization of the yeast sedimentation pattern. The roles of magnetically changed gas-transport processes, hydrostatic pressures acting on the yeast, and changes in the distribution of the yeast sedimentation, as well as the possible effects of magnetic fields on yeast respiratory systems in the observed disturbance of the proliferation are discussed. PMID:15522694

Iwasaka, Masakazu; Ikehata, Masateru; Miyakoshi, Junji; Ueno, Shoogo

2004-12-01

189

Uncommon opportunistic yeast bloodstream infections from Qatar.  

PubMed

Eleven uncommon yeast species that are associated with high mortality rates irrespective of antifungal therapy were isolated from 17/187 (201 episodes) pediatric and elderly patients with fungemia from Qatar. The samples were taken over a 6-year period (January 2004-December 2010). Isolated species included Kluyveromyces marxianus, Lodderomyces elongisporus, Lindnera fabianii, Candida dubliniensis, Meyerozyma guilliermondii, Candida intermedia, Pichia kudriavzevii, Yarrowia lipolytica, Clavispora lusitaniae, Candida pararugosa, and Wickerhamomyces anomalus. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry provided correct identifications compared with molecular analysis testing of the same isolates. Low minimal inhibitory concentrations were found when isavuconazole and voriconazole were used for all uncommon yeast species evaluated in this study. Resistance to antifungal drugs was low and remained restricted to a few species. PMID:24934803

Taj-Aldeen, Saad J; AbdulWahab, Atqah; Kolecka, Anna; Deshmukh, Anand; Meis, Jacques F; Boekhout, Teun

2014-07-01

190

Prion formation by a yeast GLFG nucleoporin  

PubMed Central

The self-assembly of proteins into higher order structures is both central to normal biology and a dominant force in disease. Certain glutamine/asparagine (Q/N)-rich proteins in the budding yeast Saccharomyces cerevisiae assemble into self-replicating amyloid-like protein polymers, or prions, that act as genetic elements in an entirely protein-based system of inheritance. The nuclear pore complex (NPC) contains multiple Q/N-rich proteins whose self-assembly has also been proposed to underlie structural and functional properties of the NPC. Here we show that an essential sequence feature of these proteins—repeating GLFG motifs—strongly promotes their self-assembly into amyloids with characteristics of prions. Furthermore, we demonstrate that Nup100 can form bona fide prions, thus establishing a previously undiscovered ability of yeast GLFG nucleoporins to adopt this conformational state in vivo. PMID:22561191

Halfmann, Randal; Wright, Jessica R.; Alberti, Simon; Lindquist, Susan; Rexach, Michael

2012-01-01

191

Genetic activity of vinylidene chloride in yeast.  

PubMed

Vinylidene chloride (VDC) was tested for its ability to induce both point mutation and mitotic gene conversion in a diploid strain (D7) of the yeast Saccharomyces cerevisiae in a suspension test with and without a mammalian microsomal activation system, and in the intrasanguineous host-mediated assay in mice. In suspension tests with D7, VCD was toxic but not genetically active without microsomal activation. When a mouse liver 10 000 X g supernatant was included in the suspension tests, dose-related increases in both point mutation and mitotic gene conversion were seen at survival levels greater than 50%, at doses of VCD above 20 mM. In the host-mediated assay, VDC induced both point mutation and mitotic gene conversion when recovered from the liver and kidneys after both acute and sub-acute dosing. Yeasts recovered from the lungs showed little, if any, increase in either point mutation or mitotic gene conversion. PMID:7027030

Bronzetti, G; Bauer, C; Corsi, C; Leporini, C; Nieri, R; del Carratore, R

1981-06-01

192

Mapping the functional yeast ABC transporter interactome  

PubMed Central

ABC transporters are a ubiquitous class of integral membrane proteins of immense clinical interest because of their strong association with human disease and pharmacology. To improve our understanding of these proteins, we used Membrane Yeast Two-Hybrid (MYTH) technology to map the protein interactome of all non-mitochondrial ABC transporters in the model organism Saccharomy cescerevisiae, and combined this data with previously reported yeast ABC transporter interactions in the BioGRID database to generate a comprehensive, integrated interactome. We show that ABC transporters physically associate with proteins involved in a surprisingly diverse range of functions. We specifically examine the importance of the physical interactions of ABC transporters in both the regulation of one another and in the modulation of proteins involved in zinc homeostasis. The interaction network presented here will be a powerful resource for increasing our fundamental understanding of the cellular role and regulation of ABC transporters. PMID:23831759

Snider, Jamie; Hanif, Asad; Lee, Mid Eum; Jin, Ke; Yu, Analyn R.; Graham, Chris; Chuk, Matthew; Damjanovic, Dunja; Wierzbicka, Marta; Tang, Priscilla; Balderes, Dina; Wong, Victoria; Jessulat, Matthew; Darowski, Katelyn D.; Luis, Bryan-Joseph San; Shevelev, Igor; Sturley, Stephen L; Boone, Charles; Greenblatt, Jack F.; Zhang, Zhaolei; Paumi, Christian M.; Babu, Mohan; Park, Hay-Oak; Michaelis, Susan; Stagljar, Igor

2013-01-01

193

Isolation of Yeast DNA Prepare in advance  

E-print Network

. · Powdered dry ice (2-4 lbs). 1. Collect 5-10 OD units of yeast cells (e.g., 5 ml saturated SD culture at OD. Vortexing too long will shear genomic DNA into small pieces. 5. Place tubes in powdered dry ice. Allow and place on ice. · TENTS buffer: 100 mM NaCl, 10 mM Tris-HCl, pH 8, 1 mM EDTA, 2% Triton X-100, 1% SDS

Aris, John P.

194

Functional artificial free-standing yeast biofilms  

Microsoft Academic Search

Here we report fabrication of artificial free-standing yeast biofilms built using sacrificial calcium carbonate-coated templates and layer-by-layer assembly of extracellular matrix-mimicking polyelectrolyte multilayers. The free-standing biofilms are freely floating multilayered films of oppositely charged polyelectrolytes and live cells incorporated in the polyelectrolyte layers. Such biofilms were initially formed on glass substrates of circular and ribbon-like shapes coated with thin layers

Svetlana A. Konnova; Mehmet Kahraman; Alsu I. Zamaleeva; Mustafa Culha; Vesselin N. Paunov; Rawil F. Fakhrullin

2011-01-01

195

The mitochondrial pathway in yeast apoptosis  

Microsoft Academic Search

Mitochondria are not only important for the energetic status of the cell, but are also the fatal organelles deciding about\\u000a cellular life and death. Complex mitochondrial features decisive for cell death execution in mammals are present and functional\\u000a in yeast: AIF and cytochrome c release to the cytosol, mitochondrial fragmentation as well as mitochondrial hyperpolarisation followed by an oxidative burst,

Tobias Eisenberg; Sabrina Büttner; Guido Kroemer; Frank Madeo

2007-01-01

196

X-ray irradiation of yeast cells  

Microsoft Academic Search

Saccharomyces Cerevisiae yeast cells were irradiated using the soft X-ray laser-plasma source at Rutherford Laboratory. The aim was to produce a selective damage of enzyme metabolic activity at the wall and membrane level (responsible for fermentation) without interfering with respiration (taking place in mitochondria) and with nuclear and DNA activity. The source was calibrated by PIN diodes and X-ray spectrometers.

Alessandra Masini; Dimitri Batani; Fabio Previdi; Aldo Conti; Francesca Pisani; Cesare Botto; Fulvia Bortolotto; Flavia Torsiello; I. C. Edmund Turcu; Ric M. Allott; Nicola Lisi; Marziale Milani; Michele Costato; Achille Pozzi; Michel Koenig

1997-01-01

197

Fermentation of Cellodextrins by Different Yeast Strains  

PubMed Central

The fermentation of cellodextrins by eight yeast species capable of fermenting cellobiose was monitored. Only two of these species, Torulopsis molischiana and T. wickerhamii, were able to ferment ?-glucosides with a degree of polymerization between one and six. These two species showed exocellular ?-glucosidase activity. Four other species were able to ferment cellotriose, and the last two species only fermented cellobiose. These latter six species produced a ?-glucosidase capable of attacking cellodextrins, but this enzyme was endocellular. PMID:16346606

Gonde, Pierre; Blondin, Bruno; Leclerc, Marc; Ratomahenina, Robert; Arnaud, Alain; Galzy, Pierre

1984-01-01

198

Debaryomyces hansenii : An Osmotolerant and Halotolerant Yeast  

Microsoft Academic Search

The yeast Debaryomyces hansenii which was isolated from saline environments such as sea water, concentrated brines, salty food, is one of the most halotolerant\\u000a species. It can grow in media containing as high as 4 M NaCl, while the growth of Saccharomyces cerevisiae is limited in media with more than 1.7 M NaCl. This species is very important for food

Monika Aggarwal; Alok K. Mondal

2009-01-01

199

A Sampling of the Yeast Proteome  

Microsoft Academic Search

In this study, we examined yeast proteins by two-dimensional (2D) gel electrophoresis and gathered quan- titative information from about 1,400 spots. We found that there is an enormous range of protein abundance and, for identified spots, a good correlation between protein abundance, mRNA abundance, and codon bias. For each molecule of well-translated mRNA, there were about 4,000 molecules of protein.

B. FUTCHER; G. I. LATTER; P. MONARDO; C. S. MCLAUGHLIN; J. I. GARRELS

1999-01-01

200

Genetic toxicity of erythrosine in yeast.  

PubMed

The genetic activity of erythrosine, a fluorescein dye used as a color additive, was studied in assays with growing cells of different strains of Saccharomyces cerevisiae. Erythrosine induced mitotic gene conversion and reverse mutation in strains D7 and XV185-14C of yeast. It failed, however, to increase mitotic recombination in strain D5. These results show that erythrosine possesses genotoxic activity for eukaryotic cells. PMID:6096707

Matula, T I; Downie, R H

1984-01-01

201

Complete DNA sequence of yeast chromosome XI  

Microsoft Academic Search

The complete DNA sequence of the yeast Saccharomyces cerevisiae chromosome XI has been determined. In addition to a compact arrangement of potential protein coding sequences, the 666,448-base-pair sequence has revealed general chromosome patterns; in particular, alternating regional variations in average base composition correlate with variations in local gene density along the chromosome. Significant discrepancies with the previously published genetic map

B. Dujon; D. Alexandraki; B. André; W. Ansorge; V. Baladron; J. P. G. Ballesta; A. Banrevi; P. A. Bolle; M. Bolotin-Fukuhara; P. Bossier; G. Bou; J. Boyer; M. J. Buitrago; G. Cherét; L. Colleaux; B. Dalgnan-Fornier; F. Del Rey; C. Dion; H. Domdey; A. Düsterhöft; S. Düsterhus; K.-D. Entian; H. Erfle; P. F. Esteban; H. Feldmann; L. Fernandes; G. M. Fobo; C. Fritz; H. Fukuhara; C. Gabel; L. Gaillon; J. M. Carcia-Cantalejo; J. J. Garcia-Ramirez; M. E. Gent; M. Ghazvini; A. Goffeau; A. Gonzaléz; D. Grothues; P. Guerreiro; J. Hegemann; N. Hewitt; F. Hilger; C. P. Hollenberg; O. Horaitis; K. J. Indge; A. Jacquier; C. M. James; J. C. Jauniaux; A. Jimenez; H. Keuchel; L. Kirchrath; K. Kleine; P. Kötter; P. Legrain; S. Liebl; E. J. Louis; A. Maia E Silva; C. Marck; A.-L. Monnier; D. Möstl; S. Müller; B. Obermaier; S. G. Oliver; C. Pallier; S. Pascolo; F. Pfeiffer; P. Philippsen; R. J. Planta; F. M. Pohl; T. M. Pohl; R. Pöhlmann; D. Portetelle; B. Purnelle; V. Puzos; M. Ramezani Rad; S. W. Rasmussen; M. Remacha; J. L. Revuelta; G.-F. Richard; M. Rieger; C. Rodrigues-Pousada; M. Rose; T. Rupp; M. A. Santos; C. Schwager; C. Sensen; J. Skala; H. Soares; F. Sor; J. Stegemann; H. Tettelin; A. Thierry; M. Tzermia; L. A. Urrestarazu; L. van Dyck; J. C. van Vliet-Reedijk; M. Valens; M. Vandenbo; C. Vilela; S. Vissers; D. von Wettstein; H. Voss; S. Wiemann; G. Xu; J. Zimmermann; M. Haasemann; I. Becker; H. W. Mewes

1994-01-01

202

The flavoproteome of the yeast Saccharomyces cerevisiae?  

PubMed Central

Genome analysis of the yeast Saccharomyces cerevisiae identified 68 genes encoding flavin-dependent proteins (1.1% of protein encoding genes) to which 47 distinct biochemical functions were assigned. The majority of flavoproteins operate in mitochondria where they participate in redox processes revolving around the transfer of electrons to the electron transport chain. In addition, we found that flavoenzymes play a central role in various aspects of iron metabolism, such as iron uptake, the biogenesis of iron–sulfur clusters and insertion of the heme cofactor into apocytochromes. Another important group of flavoenzymes is directly (Dus1-4p and Mto1p) or indirectly (Tyw1p) involved in reactions leading to tRNA-modifications. Despite the wealth of genetic information available for S. cerevisiae, we were surprised that many flavoproteins are poorly characterized biochemically. For example, the role of the yeast flavodoxins Pst2p, Rfs1p and Ycp4p with regard to their electron donor and acceptor is presently unknown. Similarly, the function of the heterodimeric Aim45p/Cir1p, which is homologous to the electron-transferring flavoproteins of higher eukaryotes, in electron transfer processes occurring in the mitochondrial matrix remains to be elucidated. This lack of information extends to the five membrane proteins involved in riboflavin or FAD transport as well as FMN and FAD homeostasis within the yeast cell. Nevertheless, several yeast flavoproteins, were identified as convenient model systems both in terms of their mechanism of action as well as structurally to improve our understanding of diseases caused by dysfunctional human flavoprotein orthologs. PMID:24373875

Gudipati, Venugopal; Koch, Karin; Lienhart, Wolf-Dieter; Macheroux, Peter

2014-01-01

203

Mechanisms of autophagy and pexophagy in yeasts.  

PubMed

Autophagy is a process of recycling of the intracellular constituents using vacuoles (lysosomes). General autophagy occurs due to involvement of highly conservative components found in all eukaryotes, from yeasts to higher plants and humans. Autophagy also could be a selective process and be involved in regulation of the cellular number of organelles, including that of peroxisomes. The process of specific autophagic peroxisome degradation is known as pexophagy. Yeasts appear to be convenient model for studying molecular mechanisms of pexophagy, and most known ATG genes (from the term AuTophaGy) were identified in yeast studies. This review examines characteristics of general autophagy, other types of autophagy as well as pexophagy, in particular, functions of Atg proteins in general autophagy and in macro- and micropexophagy. Special attention is given to mechanisms of phagophore assembly, the role of phosphatidylinositol-3-phosphate in pexophagy, the role of peroxines (proteins involved in peroxisome biogenesis) in pexophagy, as well as properties of Atg proteins specifically involved in micropexophagy. PMID:22150273

Sibirny, A A

2011-12-01

204

Ribosome Biogenesis in the Yeast Saccharomyces cerevisiae  

PubMed Central

Ribosomes are highly conserved ribonucleoprotein nanomachines that translate information in the genome to create the proteome in all cells. In yeast these complex particles contain four RNAs (>5400 nucleotides) and 79 different proteins. During the past 25 years, studies in yeast have led the way to understanding how these molecules are assembled into ribosomes in vivo. Assembly begins with transcription of ribosomal RNA in the nucleolus, where the RNA then undergoes complex pathways of folding, coupled with nucleotide modification, removal of spacer sequences, and binding to ribosomal proteins. More than 200 assembly factors and 76 small nucleolar RNAs transiently associate with assembling ribosomes, to enable their accurate and efficient construction. Following export of preribosomes from the nucleus to the cytoplasm, they undergo final stages of maturation before entering the pool of functioning ribosomes. Elaborate mechanisms exist to monitor the formation of correct structural and functional neighborhoods within ribosomes and to destroy preribosomes that fail to assemble properly. Studies of yeast ribosome biogenesis provide useful models for ribosomopathies, diseases in humans that result from failure to properly assemble ribosomes. PMID:24190922

Woolford, John L.; Baserga, Susan J.

2013-01-01

205

Engineered yeast for enhanced CO2 mineralization†  

PubMed Central

In this work, a biologically catalyzed CO2 mineralization process for the capture of CO2 from point sources was designed, constructed at a laboratory scale, and, using standard chemical process scale-up protocols, was modeled and evaluated at an industrial scale. A yeast display system in Saccharomyces cerevisae was used to screen several carbonic anhydrase isoforms and mineralization peptides for their impact on CO2 hydration, CaCO3 mineralization, and particle settling rate. Enhanced rates for each of these steps in the CaCO3 mineralization process were confirmed using quantitative techniques in lab-scale measurements. The effect of these enhanced rates on the CO2 capture cost in an industrial scale CO2 mineralization process using coal fly ash as the CaO source was evaluated. The model predicts a process using bCA2- yeast and fly ash is ~10% more cost effective per ton of CO2 captured than a process with no biological molecules, a savings not realized by wild-type yeast and high-temperature stable recombinant CA2 alone or in combination. The levelized cost of electricity for a power plant using this process was calculated and scenarios in which this process compares favorably to CO2 capture by MEA absorption process are presented.

Barbero, Roberto; Carnelli, Lino; Simon, Anna; Kao, Albert; Monforte, Alessandra d'Arminio; Ricco, Moreno; Bianchi, Daniele; Belcher, Angela

2014-01-01

206

Wood impregnation of yeast lees for winemaking.  

PubMed

This study develops a new method to produce more complex wines by means of an indirect diffusion of wood aromas from yeast cell-walls. An exogenous lyophilized biomass was macerated with an ethanol wood extract solution and subsequently dried. Different times were used for the adsorption of polyphenols and volatile compounds to the yeast cell-walls. The analysis of polyphenols and volatile compounds (by HPLC/DAD and GC-MS, respectively) demonstrate that the adsorption/diffusion of these compounds from the wood to the yeast takes place. Red wines were also aged with Saccharomyces cerevisiae lees that had been impregnated with wood aromas and subsequently dried. Four different types of wood were used: chestnut, cherry, acacia and oak. Large differences were observed between the woods studied with regards to their volatile and polyphenolic profiles. Sensory evaluations confirmed large differences even with short-term contact between the wines and the lees, showing that the method could be of interest for red wine making. In addition, the results demonstrate the potential of using woods other than oak in cooperage. PMID:25308662

Palomero, Felipe; Bertani, Paolo; Fernández de Simón, Brígida; Cadahía, Estrella; Benito, Santiago; Morata, Antonio; Suárez-Lepe, José A

2015-03-15

207

Effects of yeast immobilization on bioethanol production.  

PubMed

The current study evaluated a newer method, which includes a dehydration step, of immobilizing Saccharomyces cerevisiae L-77 and S. cerevisiae L-73 onto hydroxylapatite and chamotte ceramic supports. The efficiency of cell immobilization on chamotte was significantly higher than hydroxylapatite. Immobilized yeast preparations were investigated for their ethanol-producing capabilities. The glucose concentration in a fermentation medium was 100 mg/mL. Immobilized preparations produced the same amount of ethanol (48 ± 0.5 mg/mL) as free cells after 36 H of fermentation. During the early stages of fermentation, immobilized yeast cells produced ethanol at a higher rate than free cells. Yeast preparations immobilized on both supports (hydroxylapatite and chamotte) were successfully used in six sequential batch fermentations without any loss of activity. The chamotte support was more stable in the fermentation medium during these six cycles of ethanol production. In addition to the high level of ethanol produced by cells immobilized on chamotte, the stability of this support and its low cost make it a promising material for biotechnologies associated with ethanol production. PMID:24180336

Borovikova, Diana; Scherbaka, Rita; Patmalnieks, Aloizijs; Rapoport, Alexander

2014-01-01

208

Yeast Exocytic v-SNAREs Confer Endocytosis  

PubMed Central

In yeast, homologues of the synaptobrevin/VAMP family of v-SNAREs (Snc1 and Snc2) confer the docking and fusion of secretory vesicles at the cell surface. As no v-SNARE has been shown to confer endocytosis, we examined whether yeast lacking the SNC genes, or possessing a temperature-sensitive allele of SNC1 (SNC1ala43), are deficient in the endocytic uptake of components from the cell surface. We found that both SNC and temperature-shifted SNC1ala43 yeast are deficient in their ability to deliver the soluble dye FM4–64 to the vacuole. Under conditions in which vesicles accumulate, FM4–64 stained primarily the cytoplasm as well as fragmented vacuoles. In addition, ?-factor–stimulated endocytosis of the ?-factor receptor, Ste2, was fully blocked, as evidenced using a Ste2-green fluorescent protein fusion protein as well as metabolic labeling studies. This suggests a direct role for Snc v-SNAREs in the retrieval of membrane proteins from the cell surface. Moreover, this idea is supported by genetic and physical data that demonstrate functional interactions with t-SNAREs that confer endosomal transport (e.g., Tlg1,2). Notably, Snc1ala43 was found to be nonfunctional in cells lacking Tlg1 or Tlg2. Thus, we propose that synaptobrevin/VAMP family members are engaged in anterograde and retrograde protein sorting steps between the Golgi and the plasma membrane. PMID:11029060

Gurunathan, Sangiliyandi; Chapman-Shimshoni, Daphne; Trajkovic, Selena; Gerst, Jeffrey E.

2000-01-01

209

Evolution of the genetic code in yeasts.  

PubMed

During the last 30 years, a number of genetic code alterations have been uncovered in bacteria and in the mitochondria and cytoplasm of various eukaryotes, invalidating the hypothesis that the genetic code is universal and frozen. In the mitochondria of most yeasts, the UGA stop codon is decoded as tryptophan and the four leucine codons of the CUN family (N = any nucleotide) are decoded as threonine. Recently, a unique genetic code change involving the decoding of the leucine CUG codon as serine was discovered in the cytoplasm of Candida and Debaryomyces species, indicating that the genetic code of yeasts may be under specific evolutionary pressures whose molecular nature is not yet fully understood. This genetic code alteration is mediated by a novel serine-tRNA that acquired a leucine 5'-CAG-3' anticodon (ser-tRNACAG) through insertion of an adenosine in the intron of its gene. This event, which occurred 272 +/- 25 million years ago, reprogrammed the identity of approximately 30 000 CUG codons existent in the ancestor of these yeasts and had a profound impact on the evolution of the genus Candida and of other species. Here, we review the most recent results and concepts arising from the study of this genetic code change and highlight how its study is changing our views of the evolution of the genetic code. PMID:16498697

Miranda, Isabel; Silva, Raquel; Santos, Manuel A S

2006-02-01

210

YeastMed: an XML-Based System for Biological Data Integration of Yeast  

E-print Network

A key goal of bioinformatics is to create database systems and software platforms capable of storing and analysing large sets of biological data. Hundreds of biological databases are now available and provide access to huge amount of biological data. SGD, Yeastract, CYGD-MIPS, BioGrid and PhosphoGrid are five of the most visited databases by the yeast community. These sources provide complementary data on biological entities. Biologists are brought systematically to query these data sources in order to analyse the results of their experiments. Because of the heterogeneity of these sources, querying them separately and then manually combining the returned result is a complex and laborious task. To provide transparent and simultaneous access to these sources, we have developed a mediator-based system called YeastMed. In this paper, we present YeastMed focusing on its architecture.

Briache, Abdelaali; Kerzazi, Amine; Navas-Delgado, Ismael; Montes, Jose F Aldana; Hassani, Badr D Rossi; Lairini, Khalid

2010-01-01

211

Frontiers of yeast metabolic engineering: diversifying beyond ethanol and Saccharomyces.  

PubMed

Microbial systems provide an attractive, renewable route to produce desired organic molecules such as fuels and chemicals. While attention within the field of metabolic engineering has mostly focused on Escherichia coli, yeast is a potent host and growing host for industrial products and has many outstanding, biotechnologically desirable native traits. Thus, there has been a recent shift in focus toward yeast as production hosts to replace E. coli. As such, products have diversified in yeast beyond simply ethanol. Additionally, nonconventional yeasts have been considered to move beyond Saccharomyces cerevisiae. This review highlights recent advances in metabolic engineering of yeasts for producing value-added chemical compounds including alcohols, sugar derivatives, organic acids, fats, terpenes, aromatics, and polyketides. Furthermore, we will also discuss the future direction of metabolic engineering of yeasts. PMID:23541504

Liu, Leqian; Redden, Heidi; Alper, Hal S

2013-12-01

212

Ecology and Biodiversity of Yeasts with Potential Value in Biotechnology  

NASA Astrophysics Data System (ADS)

In the latest edition of the standard treatise of yeasts, in 1998, 700 species were described. Since then, the number of recognized yeast species has doubled, with a steep increase particularly in the number of the basidiomycetous yeasts. Of all these yeast species, only about a dozen is used at industrial scale, and some 70 - 80 species have been shown at laboratory scale to possess potential value in biotechnology; their ratio is, in the best case, 5 - 10 %. If it is accepted, that according to a modest estimate, the known yeast species represent only 5 % of the total number which may inhabit the Earth, then there is ample room to search for new species with novel potential to exploit. Where could these yeasts be discovered?

Deak, T.

213

Isolation and characterization of ethanol tolerant yeast strains.  

PubMed

Yeast strains are commonly associated with sugar rich environments. Various fruit samples were selected as source for isolating yeast cells. The isolated cultures were identified at Genus level by colony morphology, biochemical characteristics and cell morphological characters. An attempt has been made to check the viability of yeast cells under different concentrations of ethanol. Ethanol tolerance of each strain was studied by allowing the yeast to grow in liquid YEPD (Yeast Extract Peptone Dextrose) medium having different concentrations of ethanol. A total of fifteen yeast strains isolated from different samples were used for the study. Seven strains of Saccharomyces cerevisiae obtained from different fruit sources were screened for ethanol tolerance. The results obtained in this study show a range of tolerance levels between 7%-12% in all the stains. Further, the cluster analysis based on 22 RAPD (Random Amplified polymorphic DNA) bands revealed polymorphisms in these seven Saccharomyces strains. PMID:23750092

Tikka, Chiranjeevi; Osuru, Hari Prasad; Atluri, Navya; Raghavulu, Praveen Chakravarthi Veera; Yellapu, Nanda Kumar; Mannur, Ismail Shaik; Prasad, Uppu Venkateswara; Aluru, Sudheer; K, Narasimha Varma; Bhaskar, Matcha

2013-01-01

214

Not your ordinary yeast: non-Saccharomyces yeasts in wine production uncovered.  

PubMed

Saccharomyces cerevisiae and grape juice are 'natural companions' and make a happy wine marriage. However, this relationship can be enriched by allowing 'wild' non-Saccharomyces yeast to participate in a sequential manner in the early phases of grape must fermentation. However, such a triangular relationship is complex and can only be taken to 'the next level' if there are no spoilage yeast present and if the 'wine yeast' - S. cerevisiae - is able to exert its dominance in time to successfully complete the alcoholic fermentation. Winemakers apply various 'matchmaking' strategies (e.g. cellar hygiene, pH, SO2 , temperature and nutrient management) to keep 'spoilers' (e.g. Dekkera bruxellensis) at bay, and allow 'compatible' wild yeast (e.g. Torulaspora delbrueckii, Pichia kluyveri, Lachancea thermotolerans and Candida/Metschnikowia pulcherrima) to harmonize with potent S. cerevisiae wine yeast and bring the best out in wine. Mismatching can lead to a 'two is company, three is a crowd' scenario. More than 40 of the 1500 known yeast species have been isolated from grape must. In this article, we review the specific flavour-active characteristics of those non-Saccharomyces species that might play a positive role in both spontaneous and inoculated wine ferments. We seek to present 'single-species' and 'multi-species' ferments in a new light and a new context, and we raise important questions about the direction of mixed-fermentation research to address market trends regarding so-called 'natural' wines. This review also highlights that, despite the fact that most frontier research and technological developments are often focussed primarily on S. cerevisiae, non-Saccharomyces research can benefit from the techniques and knowledge developed by research on the former. PMID:24164726

Jolly, Neil P; Varela, Cristian; Pretorius, Isak S

2014-03-01

215

Relative Incidence of Ascomycetous Yeasts in Arctic Coastal Environments  

Microsoft Academic Search

Previous studies of fungi in polar environments have revealed a prevalence of basidiomycetous yeasts in soil and in subglacial\\u000a environments of polythermal glaciers. Ascomycetous yeasts have rarely been reported from extremely cold natural environments,\\u000a even though they are known contaminants of frozen foods. Using media with low water activity, we have isolated various yeast\\u000a species from the subglacial ice of

Lorena Butinar; Tadeja Strmole; Nina Gunde-Cimerman

2011-01-01

216

Genetic transformation and biotechnological application of the yeast Arxula adeninivorans  

Microsoft Academic Search

The relatively unknown, non-pathogenic, dimorphic, haploid, ascomycetous yeast Arxula adeninivorans exhibits some unusual properties which are of biotechnological interest. The yeast is able to assimilate and ferment many\\u000a compounds as sole source of carbon and\\/or nitrogen, it utilises n-alkanes and degrades starch efficiently. A. adeninivorans features such as thermo- and haloresistance as well as the yeast's uncommon growth and secretion

T. Wartmann; G. Kunze

2000-01-01

217

Components of the yeast spindle and spindle pole body  

Microsoft Academic Search

Yeast spindle pole bodies (SPBs) with at- tached nuclear microtubules were enriched ,x,600-fold from yeast cell extracts. 14 mAbs prepared against this enriched SPB fraction define at least three components of the SPB and spindle. Immunofluorescent staining of yeast cells showed that throughout the cell cycle two of the components (110 and 90 kD) were localized ex- clusively to the

Michael P. Rout; John V. Kilmartin

1990-01-01

218

Prevalence of Candida dubliniensis Isolates in a Yeast Stock Collection  

Microsoft Academic Search

To establish the historical prevalence of the novel yeast species Candida dubliniensis, a survey of 2,589 yeasts originally identified as Candida albicans and maintained in a stock collection dating back to the early 1970s was undertaken. A total of 590 yeasts, including 93 (18.5%) b-glucosidase-negative isolates among 502 isolates that showed abnormal colony colors on a differential chromogenic agar and

FRANK C. ODDS; LUC VAN NUFFEL; GERY DAMS

1998-01-01

219

Detection and identification of wild yeast in Koumiss.  

PubMed

Koumiss is a slightly alcoholic fermented mare's milk beverage, originally obtained by using a natural mixed starter of lactic acid bacteria and yeasts. Yeast is an important component of Koumiss processing which can affect the aroma, texture, as well as the nutrients beneficial to human health, but few reports have examined the yeast ecology of local ecosystems. The purpose of this study was to isolate and identify the yeast present in Koumiss from three representative regions of China using a polyphasic method. A total of 655 yeast isolates were obtained from 96 Koumiss samples collected from three regions in China. Koumiss harbored yeast populations at 5-7 log CFU/ml. Twelve different yeast species belonging to nine genera were detected in the Koumiss samples tested, including Candida pararugosa, Dekkera anomala, Geotrichum sp., Issatchenkia orientalis, Kazachstania unispora, Kluyveromyces marxianus, Pichia deserticola, Pichia fermentans, Pichia manshurica, Pichia membranaefaciens, Saccharomyces cerevisiae and Torulaspora delbrueckii. Kluyveromyces marxianus, Kazachstania unispora and Saccharomyces cerevisiae were the dominant species present in this traditional fermented dairy product. This study is the first to identify the yeast communities associated with Koumiss in China. The results enrich our knowledge of yeast in Koumiss, give us a more complete picture of the microbial diversity in Koumiss and can be used to promote the development of the local dairy industry. PMID:22608237

Mu, Zhishen; Yang, XuJin; Yuan, Hongli

2012-09-01

220

Yeast Methylotrophy: Metabolism, Gene Regulation and Peroxisome Homeostasis  

PubMed Central

Eukaryotic methylotrophs, which are able to obtain all the carbon and energy needed for growth from methanol, are restricted to a limited number of yeast species. When these yeasts are grown on methanol as the sole carbon and energy source, the enzymes involved in methanol metabolism are strongly induced, and the membrane-bound organelles, peroxisomes, which contain key enzymes of methanol metabolism, proliferate massively. These features have made methylotrophic yeasts attractive hosts for the production of heterologous proteins and useful model organisms for the study of peroxisome biogenesis and degradation. In this paper, we describe recent insights into the molecular basis of yeast methylotrophy. PMID:21754936

Yurimoto, Hiroya; Oku, Masahide; Sakai, Yasuyoshi

2011-01-01

221

Variation in yeast mitochondrial activity associated with asci.  

PubMed

An increase in mitochondrial membrane potential (DeltaPsim) and mitochondrially produced 3-hydroxy (3-OH) oxylipins was experienced in asci of the nonfermentative yeasts Galactomyces reessii and Lipomyces starkeyi and the fermentative yeasts Pichia farinosa and Schizosaccharomyces octosporus. Strikingly, asci of Zygosaccharomyces bailii showed no increase in mitochondrial activity (DeltaPsim and oxylipin production). As expected, oxygen deprivation only inhibited ascus formation in those yeasts with increased ascus mitochondrial activity. We conclude that ascus formation in yeasts is not always dependent on mitochondrial activity. In this case, fermentation may provide enough energy for ascus formation in Z. bailii. PMID:18641699

Swart, Chantel W; van Wyk, Pieter W J; Pohl, Carolina H; Kock, Johan L F

2008-07-01

222

[Biotherapeutic use of yeasts--importance of probiotic products].  

PubMed

Besides their important biotechnological and industrial applications, yeasts have been used during the last years, in obtaining probiotic products, along with lactic acid bacteria and various enzymes. Our study deals with some aspects regarding the use of yeasts as animal and human probiotics, and their possible mechanisms of action. Also, we present information on probiotic products synthesized by international and national companies. Finally, there are described future prospective of research concerning the applications of recombinant yeast strains as basis for obtaining new bio-drugs. In conclusion, the data comprised in this paper, presents an interesting argument for using yeasts as biotherapeutic agents, an alternative to conventional treatments. PMID:19241999

Ghindea, Raluca; Csutak, Ortansa; Stoica, Ileana; Vassu, Tatiana

2008-01-01

223

Effect of fungicides on epiphytic yeasts associated with strawberry  

PubMed Central

We studied the effect of two commonly used fungicides on the epiphytic yeast community of strawberry. Greenhouse and field experiments were conducted applying Switch (cyprodinil plus fludioxonil) or Signum (boscalid plus pyraclostrobin) to strawberry plants. Yeasts on leaves and fruits were assessed on treated and untreated plants at several time points via plating and denaturing gradient gel electrophoresis (DGGE) analysis. The yeast counts on plates of the treated plants were similar to the control plants. Unripe fruits had 10 times larger yeast concentrations than ripe fruits or leaves. Some dominant yeast types were isolated and in vitro tests showed that they were at least 10 times less sensitive to Switch and Signum as compared with two important fungal strawberry pathogens Botrytis cinerea and Colletotrichum acutatum, which are the targets for the fungicide control. DGGE analysis showed that the applied fungicides had no effect on the composition of the yeast communities, while the growing system, strawberry tissue, and sampling time did affect the yeast communities. The yeast species most commonly identified were Cryptococcus, Rhodotorula, and Sporobolomyces. These results point toward the potential applicability of natural occurring yeast antagonists into an integrated disease control strategy for strawberry diseases.

Debode, Jane; Van Hemelrijck, Wendy; Creemers, Piet; Maes, Martine

2013-01-01

224

Resistance to heavy metals by some Nigerian yeast strains.  

PubMed

The heavy metal resistance of yeasts isolated from sugary substrates such as orange, palm wine and pineapple and identified as Saccharomyces carlsbergensis and S. cerevisiae was studied. The yeast isolates were tested against different concentrations of cadmium, copper, manganese, silver and zinc salts ranging from 1 to 20 mmol/L. Local yeasts showed resistance to 3-15 mmol/L cadmium, 18-20 copper, 16-20 manganese, 1-9 silver and 16-19 for zinc. The significance of the results is discussed in relation to the effects of heavy metals on growth of microorganisms and selection of yeasts for the brewing industry in Nigeria. PMID:8112693

Olasupo, N A; Scott-Emuakpor, M B; Ogunshola, R A

1993-01-01

225

Artificial Cellulosomes and Arsenic Cleanup: From Single Cell Programming to Synthetic Yeast Consortium  

E-print Network

al. , 2009). Yeast cells in fermentation media were countedthe bottle stopper. Yeast cells in fermentation media wereYeast surface display of trifunctional minicellulosomes for simultaneous saccharification and fermentation

Tsai, Shen-Long

2011-01-01

226

Comparison of the Quantum II, API Yeast Ident, and AutoMicrobic systems for identification of clinical yeast isolates.  

PubMed Central

The Quantum II Yeast Identification System (Abbott Laboratories) is a microprocessor-based spectrophotometric system for identification of clinical yeast isolates within 24 h. We compared the Quantum II system with the API Yeast Ident (Analytab Products) and the AutoMicrobic System Yeast Biochemical Card (AMS-YBC; Vitek Systems, Inc.) for the identification of 221 clinical yeast isolates, including 120 common clinical isolates (Candida albicans, C. tropicalis, C. parapsilosis, Torulopsis glabrata, and Cryptococcus neoformans) and 101 relatively uncommon clinical isolates. The API 20C (Analytab) was used as the reference system. The Quantum II and AMS-YBC systems correctly identified 181 (82%) and 184 (83%) isolates, respectively, whereas the Yeast Ident system correctly identified 132 (60%) isolates. Of the 120 common clinical isolates, 113 (94%) were correctly identified by Quantum II, 103 (86%) were correctly identified by AMS-YBC, and 83 (69%) were correctly identified by Yeast Ident. Of the 101 uncommon clinical isolates tested, 68 (67%) were correctly identified by Quantum II, 81 (80%) were correctly identified by AMS-YBC, and 49 (49%) were correctly identified by Yeast Ident. The overall accuracy of the Quantum II, AMS-YBC, and API Yeast Ident was not sufficient to recommend any of these systems for routine use in the clinical microbiology laboratory without substantial expansion of the respective data bases. PMID:3182994

Pfaller, M A; Preston, T; Bale, M; Koontz, F P; Body, B A

1988-01-01

227

Yeast and Mammalian Metallothioneins Functionally Substitute for Yeast Copper-Zinc Superoxide Dismutase  

NASA Astrophysics Data System (ADS)

Copper-zinc superoxide dismutase catalyzes the disproportionation of superoxide anion to hydrogen peroxide and dioxygen and is thought to play an important role in protecting cells from oxygen toxicity. Saccharomyces cerevisiae strains lacking copper-zinc superoxide dismutase, which is encoded by the SOD1 gene, are sensitive to oxidative stress and exhibit a variety of growth defects including hypersensitivity to dioxygen and to superoxide-generating drugs such as paraquat. We have found that in addition to these known phenotypes, SOD1-deletion strains fail to grow on agar containing the respiratory carbon source lactate. We demonstrate here that expression of the yeast or monkey metallothionein proteins in the presence of copper suppresses the lactate growth defect and some other phenotypes associated with SOD1-deletion strains, indicating that copper metallothioneins substitute for copper-zinc superoxide dismutase in vivo to protect cells from oxygen toxicity. Consistent with these results, we show that yeast metallothionein mRNA levels are dramatically elevated under conditions of oxidative stress. Furthermore, in vitro assays demonstrate that yeast metallothionein, purified or from whole-cell extracts, exhibits copper-dependent antioxidant activity. Taken together, these data suggest that both yeast and mammalian metallothioneins may play a direct role in the cellular defense against oxidative stress by functioning as antioxidants.

Tamai, Katherine T.; Gralla, Edith B.; Ellerby, Lisa M.; Valentine, Joan S.; Thiele, Dennis J.

1993-09-01

228

Yeast through the ages: A statistical analysis of genetic changes in aging yeast  

E-print Network

for a given yeast sample all the genetic information is isolated to one cell. To study the genetic effects', 6420 spots contained genetic information of interest, the remaining spots were either control genes or spots on the array that were empty of genetic information. Throughout the paper, we'll refer to 6420

Hardin, Jo

229

Genetically modified yeast species, and fermentation processes using genetically modified yeast  

DOEpatents

Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

Rajgarhia, Vineet; Koivuranta, Kari; Penttila, Merja; Ilmen, Marja; Suominen, Pirkko; Aristidou, Aristos; Miller, Christopher Kenneth; Olson, Stacey; Ruohonen, Laura

2013-05-14

230

Genetically modified yeast species and fermentation processes using genetically modified yeast  

DOEpatents

Yeast cells are transformed with an exogenous xylose isomerase gene. Additional genetic modifications enhance the ability of the transformed cells to ferment xylose to ethanol or other desired fermentation products. Those modifications', include deletion of non-specific or specific aldose reductase gene(s), deletion of xylitol dehydrogenase gene(s) and/or overexpression of xylulokinase.

Rajgarhia, Vineet (Kingsport, TN); Koivuranta, Kari (Helsinki, FI); Penttila, Merja (Helsinki, FI); Ilmen, Marja (Helsinki, FI); Suominen, Pirkko (Maple Grove, MN); Aristidou, Aristos (Maple Grove, MN); Miller, Christopher Kenneth (Cottage Grove, MN); Olson, Stacey (St. Bonifacius, MN); Ruohonen, Laura (Helsinki, FI)

2011-05-17

231

Genetic Influences on Translation in Yeast  

PubMed Central

Heritable differences in gene expression between individuals are an important source of phenotypic variation. The question of how closely the effects of genetic variation on protein levels mirror those on mRNA levels remains open. Here, we addressed this question by using ribosome profiling to examine how genetic differences between two strains of the yeast S. cerevisiae affect translation. Strain differences in translation were observed for hundreds of genes. Allele specific measurements in the diploid hybrid between the two strains revealed roughly half as many cis-acting effects on translation as were observed for mRNA levels. In both the parents and the hybrid, most effects on translation were of small magnitude, such that the direction of an mRNA difference was typically reflected in a concordant footprint difference. The relative importance of cis and trans acting variation on footprint levels was similar to that for mRNA levels. There was a tendency for translation to cause larger footprint differences than expected given the respective mRNA differences. This is in contrast to translational differences between yeast species that have been reported to more often oppose than reinforce mRNA differences. Finally, we catalogued instances of premature translation termination in the two yeast strains and also found several instances where erroneous reference gene annotations lead to apparent nonsense mutations that in fact reside outside of the translated gene body. Overall, genetic influences on translation subtly modulate gene expression differences, and translation does not create strong discrepancies between genetic influences on mRNA and protein levels. PMID:25340754

Albert, Frank W.; Muzzey, Dale; Weissman, Jonathan S.; Kruglyak, Leonid

2014-01-01

232

Visualization of yeast cells by electron microscopy.  

PubMed

In the 1970s, hydrocarbon or methanol utilizable yeasts were considered as a material for foods and ethanol production. During the course of studies into the physiology of yeasts, we found that these systems provide a suitable model for the biogenesis and ultrastructure research of microbodies (peroxisomes). Microbodies of hydrocarbon utilizing Candida tropicalis multiply profusely from the preexisting microbody. ? oxidation enzymes in the microbody were determined by means of immunoelectron microscopy. We examined the ultrastructure of Candida boidinii microbodies grown on methanol, and found a composite crystalloid of two enzymes, alcohol oxidase and catalase, by analyzing using the optical diffraction and filtering technique and computer simulation. We established methods for preparing the protoplasts of Schizosaccharomyces pombe and conditions for the complete regeneration of the cell wall. The dynamic process of cell wall formation was clarified through our study of the protoplasts, using an improved ultra high resolution (UHR) FESEM S-900 and an S-900LV. It was found that ?-1,3-glucan, ?-1,6-glucan and ?-1,3-glucan, as well as ?-galactomannan, are ingredients of the cell wall. The process of septum formation during cell division was examined after cryo-fixation by high pressure freezing (HPF). It was also found that ?-1,3- and ?-1,3-glucans were located in the invaginating nascent septum, and later, highly branched ?-1,6-glucan also appeared on the second septum. The micro-sampling method, using a focused ion beam (FIB), has been applied to our yeast cell wall research. A combination of FIB and scanning transmission electron microscopy is useful in constructing 3D images and analyzing the molecular architecture of cells, as well as for electron tomography of thick sections of biological specimens. PMID:23231852

Osumi, Masako

2012-01-01

233

Crystal structure of yeast Sco1  

SciTech Connect

The Sco family of proteins are involved in the assembly of the dinuclear CuA site in cytochrome c oxidase (COX), the terminal enzyme in aerobic respiration. These proteins, which are found in both eukaryotes and prokaryotes, are characterized by a conserved CXXXC sequence motif that binds copper ions and that has also been proposed to perform a thiol:disulfide oxidoreductase function. The crystal structures of Saccharomyces cerevisiae apo Sco1 (apo-ySco1) and Sco1 in the presence of copper ions (Cu-ySco1) were determined to 1.8- and 2.3-{angstrom} resolutions, respectively. Yeast Sco1 exhibits a thioredoxin-like fold, similar to that observed for human Sco1 and a homolog from Bacillus subtilis. The Cu-ySco1 structure, obtained by soaking apo-ySco1 crystals in copper ions, reveals an unexpected copper-binding site involving Cys181 and Cys216, cysteine residues present in ySco1 but not in other homologs. The conserved CXXXC cysteines, Cys148 and Cys152, can undergo redox chemistry in the crystal. An essential histidine residue, His239, is located on a highly flexible loop, denoted the Sco loop, and can adopt positions proximal to both pairs of cysteines. Interactions between ySco1 and its partner proteins yeast Cox17 and yeast COX2 are likely to occur via complementary electrostatic surfaces. This high-resolution model of a eukaryotic Sco protein provides new insight into Sco copper binding and function.

Abajian, Carnie; Rosenzweig, Amy C. (NWU)

2010-03-05

234

Osmotic Stress Signaling and Osmoadaptation in Yeasts  

PubMed Central

The ability to adapt to altered availability of free water is a fundamental property of living cells. The principles underlying osmoadaptation are well conserved. The yeast Saccharomyces cerevisiae is an excellent model system with which to study the molecular biology and physiology of osmoadaptation. Upon a shift to high osmolarity, yeast cells rapidly stimulate a mitogen-activated protein (MAP) kinase cascade, the high-osmolarity glycerol (HOG) pathway, which orchestrates part of the transcriptional response. The dynamic operation of the HOG pathway has been well studied, and similar osmosensing pathways exist in other eukaryotes. Protein kinase A, which seems to mediate a response to diverse stress conditions, is also involved in the transcriptional response program. Expression changes after a shift to high osmolarity aim at adjusting metabolism and the production of cellular protectants. Accumulation of the osmolyte glycerol, which is also controlled by altering transmembrane glycerol transport, is of central importance. Upon a shift from high to low osmolarity, yeast cells stimulate a different MAP kinase cascade, the cell integrity pathway. The transcriptional program upon hypo-osmotic shock seems to aim at adjusting cell surface properties. Rapid export of glycerol is an important event in adaptation to low osmolarity. Osmoadaptation, adjustment of cell surface properties, and the control of cell morphogenesis, growth, and proliferation are highly coordinated processes. The Skn7p response regulator may be involved in coordinating these events. An integrated understanding of osmoadaptation requires not only knowledge of the function of many uncharacterized genes but also further insight into the time line of events, their interdependence, their dynamics, and their spatial organization as well as the importance of subtle effects. PMID:12040128

Hohmann, Stefan

2002-01-01

235

How does yeast respond to pressure?  

PubMed

The brewing and baking yeast Saccharomyces cerevisiae has been used as a model for stress response studies of eukaryotic cells. In this review we focus on the effect of high hydrostatic pressure (HHP) on S. cerevisiae. HHP exerts a broad effect on yeast cells characteristic of common stresses, mainly associated with protein alteration and lipid bilayer phase transition. Like most stresses, pressure induces cell cycle arrest. Below 50 MPa (500 atm) yeast cell morphology is unaffected whereas above 220 MPa wild-type cells are killed. S. cerevisiae cells can acquire barotolerance if they are pretreated with a sublethal stress due to temperature, ethanol, hydrogen peroxide, or pressure. Nevertheless, pressure only leads to protection against severe stress if, after pressure pretreatment, the cells are also re-incubated at room pressure. We attribute this effect to the inhibition of the protein synthesis apparatus under HHP. The global genome expression analysis of S. cerevisiae cells submitted to HHP revealed a stress response profile. The majority of the up-regulated genes are involved in stress defense and carbohydrate metabolism while most repressed genes belong to the cell cycle progression and protein synthesis categories. However, the signaling pathway involved in the pressure response is still to be elucidated. Nitric oxide, a signaling molecule involved in the regulation of a large number of cellular functions, confers baroprotection. Furthermore, S. cerevisiae cells in the early exponential phase submitted to 50-MPa pressure show induction of the expression level of the nitric oxide synthase inducible isoform. As pressure becomes an important biotechnological tool, studies concerning this kind of stress in microorganisms are imperative. PMID:16082465

Fernandes, P M B

2005-08-01

236

Modification of yeast ribosomal proteins. Methylation.  

PubMed Central

Two-dimensional polyacrylamide-gel electrophoretic analysis of yeast ribosomal proteins uniformly labelled in vivo with [methyl-3H]methionine and [1-14C]methionine revealed that four ribosomal proteins are methylated, i.e. proteins S31, S32, L15 and L41. Lysine and arginine appear to be the predominant acceptors of the methyl groups. The degree of methylation ranges from 0.09 to 0.20 methyl group per modified ribosomal protein species. PMID:367366

Kruiswijk, T; Kunst, A; Planta, R J; Mager, W H

1978-01-01

237

Multiple dextranases from the yeast Lipomyces starkeyi  

Microsoft Academic Search

The soil yeast Lipomyces starkeyi (NCYC 1436) secretes dextranase activity into the growth medium. Resolution of a dextranase-active protein fraction by SDS-PAGE\\u000a produced three protein bands, of 66 kDa, 68 kDa and 78 kDa, and isoelectric focusing of the same fraction resulted in seven\\u000a protein bands, of pIs 3.50, 3.85, 4.20, 4.80, 4.85, 5.00 and 5.30. Dextranase activity was demonstrated for all the

Stefan H. Millson; Ivor Howell Evans

2007-01-01

238

Ascorbic acid specific utilization by some yeasts.  

PubMed

One hundred and eighty strains of yeasts belonging to 17 genus and 53 species were screened for their ability to grow on ascorbic acid and iso-ascorbic acid as the sole carbon source. Most of the tested strains (157) were unable to grow on either compound. Strains of seven species of the genus Cryptococcus, of two Candida species, of Filobasidiella neoformans, Trichosporon cutaneum, Lipomyces starkeyi, Hansenula capsulata, and one strain of Aureobasidium pullulans were able to grow on ascorbic as well as on iso-ascorbic acid. Conversely, four strains of Aureobasidium pullulans, Candida blankii, and Cryptococcus dimennae could use only ascorbic acid for growth. PMID:3779527

Costamagna, L; Rosi, I; Garuccio, I; Arrigoni, O

1986-09-01

239

Fanconi-like crosslink repair in yeast  

PubMed Central

Interstrand crosslinks covalently link complementary DNA strands, block replication and transcription, and can trigger cell death. In eukaryotic systems several pathways, including the Fanconi Anemia pathway, are involved in repairing interstrand crosslinks, but their precise mechanisms remain enigmatic. The lack of functional homologs in simpler model organisms has significantly hampered progress in this field. Two recent studies have finally identified a Fanconi-like interstrand crosslink repair pathway in yeast. Future studies in this simplistic model organism promise to greatly improve our basic understanding of complex interstrand crosslink repair pathways like the Fanconi pathway. PMID:23062727

2012-01-01

240

Molecular Complementarity of Yeast Glycoprotein Mating Factors  

PubMed Central

Cell fusion between opposite mating types 5 and 21 of the yeast Hansenula wingei is initiated by a strong sexual agglutination reaction. The mating factors responsible for the specificity of cellular recognition are complementary glycoproteins which form a physical complex in vitro. The complex is assayed by recovery of agglutination activity of the multivalent 5-factor after the univalent 21-factor has been inactivated by treatment of the complex with alkali. The 5-factor·21-factor complex, purified on Sepharose 6B, is large (several million daltons) and heterogeneous. The three peaks of 5-factor activity contain a number of combining sites proportional to molecular size. PMID:4521055

Crandall, Marjorie; Lawrence, Lawrence M.; Saunders, Robert M.

1974-01-01

241

Molecular complementarity of yeast glycoprotein mating factors.  

PubMed

Cell fusion between opposite mating types 5 and 21 of the yeast Hansenula wingei is initiated by a strong sexual agglutination reaction. The mating factors responsible for the specificity of cellular recognition are complementary glycoproteins which form a physical complex in vitro. The complex is assayed by recovery of agglutination activity of the multivalent 5-factor after the univalent 21-factor has been inactivated by treatment of the complex with alkali. The 5-factor.21-factor complex, purified on Sepharose 6B, is large (several million daltons) and heterogeneous. The three peaks of 5-factor activity contain a number of combining sites proportional to molecular size. PMID:4521055

Crandall, M; Lawrence, L M; Saunders, R M

1974-01-01

242

Exploring the Ubiquitin-Proteasome Protein Degradation Pathway in Yeast  

ERIC Educational Resources Information Center

This article describes an undergraduate biochemistry laboratory investigating the ubiquitin-proteasome pathway in yeast. In this exercise, the enzyme beta-galactosidase (beta-gal) is expressed in yeast under the control of a stress response promoter. Following exposure to heat stress to induce beta-gal expression, cycloheximide is added to halt…

Will, Tamara J.; McWatters, Melissa K.; McQuade, Kristi L.

2006-01-01

243

Medical significance of the so-called black yeasts  

Microsoft Academic Search

Infections caused by the black yeasts (leveduras pretas) are reviewed with respect to their clinical manifestations, classification under the umbrella term, phaeohyphomycosis, and differentiation from chromoblastomycosis. Data on the prevalence of black yeasts submitted to a national reference diagnostic center are provided. Cases of phaeohyphomycosis caused by Aureobasidium pullulans, Exophiala jeanselmei, E. moniliae, E. spinifera, Phaeoannelomyces werneckii, Phaeosclera dematioirles, Sarcinomyces

T. Matsumoto; A. A. Padhye; L. Ajello

1987-01-01

244

tRNA genes and retroelements in the yeast genome.  

PubMed Central

A survey of tRNA genes and retroelements (Ty) in the genome of the yeast Saccharomyces cerevisiae is presented. Aspects of genomic organization and evolution of these genetic entities and their interplay are discussed. Attention is also given to the relationship between tRNA gene multiplicity and codon selection in yeast and the role of Ty elements. PMID:9443958

Hani, J; Feldmann, H

1998-01-01

245

Yeast activator proteins and stress response: an overview  

Microsoft Academic Search

Yeast, and especially Saccharomyces cerevisiae, are continuously exposed to rapid and drastic changes in their external milieu. Therefore, cells must maintain their homeostasis, which is achieved through a highly coordinated gene expression involving a plethora of transcription factors, each of them performing specific functions. Here, we discuss recent advances in our understanding of the function of the yeast activator protein

Claudina Amélia Rodrigues-Pousada; Tracy Nevitt; Regina Menezes; Dulce Azevedo; Jorge Pereira; Catarina Amaral

2004-01-01

246

Landfill Leachate Treatment by Yeast and Bacteria Based Membrane Bioreactors  

Microsoft Academic Search

Biological treatment of medium-age landfill leachate was investigated on a membrane bioreactor. The experiments were conducted in two 5-L reactors with immersed hollow fiber microfiltration membranes. One reactor was operated with a mixed bacterial culture termed as bacteria based membrane bioreactor (BMBR) while the other with mixed yeast culture termed as yeast based membrane bioreactor (YMBR). The leachate was characterized

B. Wichitsathian; S. Sindhuja; C. Visvanathan; K. H. Ahn

2004-01-01

247

Systematic Management and Analysis of Yeast Gene Expression Data  

E-print Network

Systematic Management and Analysis of Yeast Gene Expression Data John Aach, Wayne Rindone the ExpressDB database for yeast RNA expression data and loaded it with 17.5 million pieces of data reported), which exhibit increased error, on our web site http://arep.med.harvard.edu/ExpressDB. We recommend

Church, George M.

248

Starch utilization by yeasts: mutants resistant of carbon catabolite repression  

Microsoft Academic Search

Twenty-seven yeasts were screened for starch breakdown; the three with the highest rate were strains of Filobasidium capsuligenum, Lipomyces starkeyi and Schwanniomyces occidentalis. Of these, only the last gave mutants with diminished carbon catabolite repression and, hence, enhanced amylase activity. Unlike those yeasts previously reported to break down starch rapidly, these mutants had the commercially advantageous characteristic of growing only

A. Kate McCann; J. A. Barnett

1984-01-01

249

High ethanol tolerance yeast for production of ethanol  

SciTech Connect

The subject of ethanol tolerance in yeasts has been receiving considerable attention as result of renewed interest in ethanol as a fuel source. Fermentation of sugars to ethanol is being studied in our laboratory using a genetically engineered yeast strain 1400. Results are described.

Krishnan, M.S.; Tsao, G.T.; Kasthurikrishnan, N. [Purdue Univ., West Lafayette, IN (United States)] [and others

1995-12-01

250

Dynamics of Cell Shape Inheritance in Fission Yeast  

E-print Network

form one of the strongest non-covalent bonds in nature [63], whereas lectins have been extensively documented to bind yeast cell wall mannan [64]). After three washes with YES medium, cells were incubated 10 minutes in a dilution 1:500 Fission Yeast...

Abenza, Juan F.; Chessel, Anatole; Raynaud, William G.; Carazo-Salas, Rafael E.

2014-09-11

251

A virtual lab for exploring the yeast prion  

E-print Network

A virtual lab for exploring the ¢¡¤£¦¥¨§© yeast prion Jacqueline L. Whalley , Mick F. Tuite within the cell of a prion protein in yeast. The biological background to the project is outlined for this transformation process. Abnormal forms of proteins which have this infectious property and known as prion

Kent, University of

252

Yeast Sequencing Report Identification of a Candida glabrata homologue of  

E-print Network

Yeast Sequencing Report Identification of a Candida glabrata homologue of the S. cerevisiae VRG4 from the pathogenic yeast, Candida glabrata, by functional complementation of an S. cerevisiae vrg4 John Wiley & Sons, Ltd. Keywords: glycosylation; Candida glabrata; nucleotide sugar transporter; GDP

Citovsky, Vitaly

253

ORIGINAL PAPER Candida gelsemii sp. nov., a yeast  

E-print Network

ORIGINAL PAPER Candida gelsemii sp. nov., a yeast of the Metschnikowiaceae clade isolated from+Business Media B.V. 2006 Abstract A new yeast species, Candida gelsemii, is described to accommodate three of Metschnikowia and Candida species known to occur in association with nectars and bees, as well as marine inverte

Thomson, James D.

254

Inhibition of Listeria monocytogenes by Food-Borne Yeasts  

PubMed Central

Many bacteria are known to inhibit food pathogens, such as Listeria monocytogenes, by secreting a variety of bactericidal and bacteriostatic substances. In sharp contrast, it is unknown whether yeast has an inhibitory potential for the growth of pathogenic bacteria in food. A total of 404 yeasts were screened for inhibitory activity against five Listeria monocytogenes strains. Three hundred and four of these yeasts were isolated from smear-ripened cheeses. Most of the yeasts were identified by Fourier transform infrared spectroscopy. Using an agar-membrane screening assay, a fraction of approximately 4% of the 304 red smear cheese isolates clearly inhibited growth of L. monocytogenes. Furthermore, 14 out of these 304 cheese yeasts were cocultivated with L. monocytogenes WSLC 1364 on solid medium to test the antilisterial activity of yeast in direct cell contact with Listeria. All yeasts inhibited L. monocytogenes to a low degree, which is most probably due to competition for nutrients. However, one Candida intermedia strain was able to reduce the listerial cell count by 4 log units. Another four yeasts, assigned to C. intermedia (three strains) and Kluyveromyces marxianus (one strain), repressed growth of L. monocytogenes by 3 log units. Inhibition of L. monocytogenes was clearly pronounced in the cocultivation assay, which simulates the conditions and contamination rates present on smear cheese surfaces. We found no evidence that the unknown inhibitory molecule is able to diffuse through soft agar. PMID:16391059

Goerges, Stefanie; Aigner, Ulrike; Silakowski, Barbara; Scherer, Siegfried

2006-01-01

255

Improving industrial yeast strains: exploiting natural and artificial diversity.  

PubMed

Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as 'global transcription machinery engineering' (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

Steensels, Jan; Snoek, Tim; Meersman, Esther; Nicolino, Martina Picca; Voordeckers, Karin; Verstrepen, Kevin J

2014-09-01

256

Fuel Ethanol Production from Molasses by Some Indigenous Yeast Isolates  

Microsoft Academic Search

In view of the anticipated shortage of the traditional supplies of fossil fuels there is a great deal of interest in production of ethanol as an alternative biofuel in recent years. The present report describes the search for potential yeast isolates from various ferments capable of producing ethanol. Twenty-one indigenous yeast isolates were recovered from various sources. Thirteen of them

Sabera Hasibe Sheela; M Firoz Ahmed; Donald James Gomes

2008-01-01

257

BIOCONTROL ACTIVITY OF ANTAGONISTIC YEASTS AGAINST PENICILLIUM EXPANSUM ON APPLE  

Microsoft Academic Search

SUMMARY Penicillium expansum causes severe rots on apple fruit during storage and shelf life. Aiming at the devel- opment of new antagonistic yeast active in controlling postharvest pathogens of fruit, several isolates were ob- tained from fig (Ficus carica) and cactus pear (Opuntia ficus-indica) grown in untreated orchards in Northern Sardinia (Italy). Two yeast strains of Candida guiller- mondii were

B. Scherm; G. Ortu; A. Muzzu; M. Budroni; G. Arras; Q. Migheli

258

Analysis of the RNA Content of the Yeast "Saccharomyces Cerevisiae"  

ERIC Educational Resources Information Center

In this article, the authors describe an interconnected set of relatively simple laboratory experiments in which students determine the RNA content of yeast cells and use agarose gel electrophoresis to separate and analyze the major species of cellular RNA. This set of experiments focuses on RNAs from the yeast "Saccharomyces cerevisiae", a…

Deutch, Charles E.; Marshall, Pamela A.

2008-01-01

259

Tolerance of budding yeast Saccharomyces cerevisiae to ultra high pressure  

NASA Astrophysics Data System (ADS)

Our studies on the tolerance of plants and animals against very high pressure of several GPa have been extended to a smaller sized fungus, the budding yeast Saccharomyces cerevisiae. Several pieces of budding yeast (dry yeast) were sealed in a small teflon capsule with a liquid pressure medium fluorinate, and exposed to 7.5 GPa by using a cubic anvil press. The pressure was kept constant for various duration of time from 2 to 24 h. After the pressure was released, the specimens were brought out from the teflon capsule, and they were cultivated on a potato dextrose agar. It was found that the budding yeast exposed to 7.5 GPa for up to 6 h showed multiplication. However, those exposed to 7.5 GPa for longer than 12 h were found dead. The high pressure tolerance of budding yeast is a little weaker than that of tardigrades.

Shibata, M.; Torigoe, M.; Matsumoto, Y.; Yamamoto, M.; Takizawa, N.; Hada, Y.; Mori, Y.; Takarabe, K.; Ono, F.

2014-05-01

260

Yeast cell factories for fine chemical and API production  

PubMed Central

This review gives an overview of different yeast strains and enzyme classes involved in yeast whole-cell biotransformations. A focus was put on the synthesis of compounds for fine chemical and API (= active pharmaceutical ingredient) production employing single or only few-step enzymatic reactions. Accounting for recent success stories in metabolic engineering, the construction and use of synthetic pathways was also highlighted. Examples from academia and industry and advances in the field of designed yeast strain construction demonstrate the broad significance of yeast whole-cell applications. In addition to Saccharomyces cerevisiae, alternative yeast whole-cell biocatalysts are discussed such as Candida sp., Cryptococcus sp., Geotrichum sp., Issatchenkia sp., Kloeckera sp., Kluyveromyces sp., Pichia sp. (including Hansenula polymorpha = P. angusta), Rhodotorula sp., Rhodosporidium sp., alternative Saccharomyces sp., Schizosaccharomyces pombe, Torulopsis sp., Trichosporon sp., Trigonopsis variabilis, Yarrowia lipolytica and Zygosaccharomyces rouxii. PMID:18684335

Pscheidt, Beate; Glieder, Anton

2008-01-01

261

Stationary phase in the yeast Saccharomyces cerevisiae.  

PubMed Central

Growth and proliferation of microorganisms such as the yeast Saccharomyces cerevisiae are controlled in part by the availability of nutrients. When proliferating yeast cells exhaust available nutrients, they enter a stationary phase characterized by cell cycle arrest and specific physiological, biochemical, and morphological changes. These changes include thickening of the cell wall, accumulation of reserve carbohydrates, and acquisition of thermotolerance. Recent characterization of mutant cells that are conditionally defective only for the resumption of proliferation from stationary phase provides evidence that stationary phase is a unique developmental state. Strains with mutations affecting entry into and survival during stationary phase have also been isolated, and the mutations have been shown to affect at least seven different cellular processes: (i) signal transduction, (ii) protein synthesis, (iii) protein N-terminal acetylation, (iv) protein turnover, (v) protein secretion, (vi) membrane biosynthesis, and (vii) cell polarity. The exact nature of the relationship between these processes and survival during stationary phase remains to be elucidated. We propose that cell cycle arrest coordinated with the ability to remain viable in the absence of additional nutrients provides a good operational definition of starvation-induced stationary phase. PMID:8393130

Werner-Washburne, M; Braun, E; Johnston, G C; Singer, R A

1993-01-01

262

Yeast lipid metabolism at a glance.  

PubMed

During the last decades, lipids have gained much attention due to their involvement in health and disease. Lipids are required for the formation of membranes and contribute to many different processes such as cell signaling, energy supply, and cell death. Various organelles such as the endoplasmic reticulum, mitochondria, peroxisomes, and lipid droplets are involved in lipid metabolism. The yeast Saccharomyces cerevisiae has become a reliable model organism to study biochemistry, molecular biology, and cell biology of lipids. The availability of mutants bearing defects in lipid metabolic pathways and the ease of manipulation by culture conditions facilitated these investigations. Here, we summarize the current knowledge about lipid metabolism in yeast. We grouped this large topic into three sections dealing with (1) fatty acids; (2) membrane lipids; and (3) storage lipids. Fatty acids serve as building blocks for the synthesis of membrane lipids (phospholipids, sphingolipids) and storage lipids (triacylglycerols, steryl esters). Phospholipids, sterols, and sphingolipids are essential components of cellular membranes. Recent investigations addressing lipid synthesis, degradation, and storage as well as regulatory aspects are presented. The role of enzymes governing important steps of the different lipid metabolic pathways is described. Finally, the link between lipid metabolic and dynamic processes is discussed. PMID:24520995

Klug, Lisa; Daum, Günther

2014-05-01

263

Copper exposure effects on yeast mitochondrial proteome.  

PubMed

Mitochondria play an important role on the entire cellular copper homeostatic mechanisms. Alteration of cellular copper levels may thus influence mitochondrial proteome and its investigation represents an important contribution to the general understanding of copper-related cellular effects. In these study we have performed an organelle targeted proteomic investigation focusing our attention on the effect of non-lethal 1mM copper concentration on Saccharomyces cerevisiae mitochondrial proteome. Functional copper effects on yeast mitochondrial proteome were evaluated by using both 2D electrophoresis (2-DE) and liquid chromatography coupled with tandem mass spectrometry. Proteomic data have been then analyzed by different unsupervised meta-analysis approaches that highlight the impairment of mitochondrial functions and the activation of oxidative stress response. Interestingly, our data have shown that stress response generated by 1mM copper treatment determines the activation of S. cerevisiae survival pathway. To investigate these findings we have treated yeast cells responsiveness to copper with hydrogen peroxide and observed a protective role of this metal. These results are suggestive of a copper role in the protection from oxidative stress possibly due to the activation of mechanisms involved in cellular survival and growth. PMID:21549866

Banci, Lucia; Bertini, Ivano; Ciofi-Baffoni, Simone; D'Alessandro, Annamaria; Jaiswal, Deepa; Marzano, Valeria; Neri, Sara; Ronci, Maurizio; Urbani, Andrea

2011-10-19

264

Nanomechanics of Yeast Surfaces Revealed by AFM  

NASA Astrophysics Data System (ADS)

Despite the large and well-documented characterization of the microbial cell wall in terms of chemical composition, the determination of the mechanical properties of surface molecules in relation to their function remains a key challenge in cell biology.The emergence of powerful tools allowing molecular manipulations has already revolutionized our understanding of the surface properties of fungal cells. At the frontier between nanophysics and molecular biology, atomic force microscopy (AFM), and more specifically single-molecule force spectroscopy (SMFS), has strongly contributed to our current knowledge of the cell wall organization and nanomechanical properties. However, due to the complexity of the technique, measurements on live cells are still at their infancy.In this chapter, we describe the cell wall composition and recapitulate the principles of AFM as well as the main current methodologies used to perform AFM measurements on live cells, including sample immobilization and tip functionalization.The current status of the progress in probing nanomechanics of the yeast surface is illustrated through three recent breakthrough studies. Determination of the cell wall nanostructure and elasticity is presented through two examples: the mechanical response of mannoproteins from brewing yeasts and elasticity measurements on lacking polysaccharide mutant strains. Additionally, an elegant study on force-induced unfolding and clustering of adhesion proteins located at the cell surface is also presented.

Dague, Etienne; Beaussart, Audrey; Alsteens, David

265

Speciation of chromium in chromium yeast.  

PubMed

High-performance liquid chromatography was used to separate Cr(III) and Cr(VI) in samples with detection by inductively coupled plasma mass spectrometry(ICP-MS). The separation was achieved on a weak anion exchange column. The mobile phase was pH 7.0 ammonium nitrate solution. The redox reaction between Cr(III) and Cr(VI) was avoided during separation and determination. This separation method could be used to separate the samples with large concentration differences between Cr(III) and Cr(VI). The alkaline digestion was used to extract chromium in solid sample, which had no effect on the retention time and the peak area of the Cr(VI). However, the conversion of Cr(VI) from Cr(III) was observed during alkaline digestion, which displayed positive relation with the ratio of Cr(III) and Cr(VI) in samples. Both Cr(III) and Cr(VI) contents of chromium yeasts cultured in media with different chromium additions were determined. The spike recoveries of Cr(VI) for chromium yeasts were in the range of 95-108 %. PMID:25269546

Guo, Xuena; Liu, Wei; Bai, Xuejing; He, Xiuping; Zhang, Borun

2014-12-01

266

The architecture of yeast DNA polymerase ?  

PubMed Central

Summary DNA polymerase ? (Pol?) is specialized for the extension step of translesion DNA synthesis (TLS). Despite its central role in maintaining genome integrity, little is known about its overall architecture. Initially identified as a homodimer of the catalytic subunit Rev3 and the accessory subunit Rev7, yeast Pol? has recently been shown to form a stable four-subunit enzyme (Pol?-d) upon incorporation of Pol31 and Pol32, the accessory subunits of yeast Pol?. To understand the 3-D architecture and assembly of Pol? and Pol?-d we employed electron microscopy. We show here how the catalytic and accessory subunits of Pol? and Pol?-d are organized relative to each other. In particular, we show that Pol?-d has a bilobal architecture resembling the replicative polymerases, and that Pol32 lies in proximity to Rev7. Collectively, our study provides the first views of Pol? and Pol?-d, and a structural framework for understanding their roles in DNA damage bypass. PMID:24120860

Gomez-Llorente, Yacob; Malik, Radhika; Jain, Rinku; Choudhury, Jayati Roy; Johnson, Robert E.; Prakash, Louise; Prakash, Satya; Ubarretxena-Belandia, Iban; Aggarwal, Aneel K.

2013-01-01

267

Quantitative analysis of colony morphology in yeast  

PubMed Central

Microorganisms often form multicellular structures such as biofilms and structured colonies that can influence the organism’s virulence, drug resistance, and adherence to medical devices. Phenotypic classification of these structures has traditionally relied on qualitative scoring systems that limit detailed phenotypic comparisons between strains. Automated imaging and quantitative analysis have the potential to improve the speed and accuracy of experiments designed to study the genetic and molecular networks underlying different morphological traits. For this reason, we have developed a platform that uses automated image analysis and pattern recognition to quantify phenotypic signatures of yeast colonies. Our strategy enables quantitative analysis of individual colonies, measured at a single time point or over a series of time-lapse images, as well as the classification of distinct colony shapes based on image-derived features. Phenotypic changes in colony morphology can be expressed as changes in feature space trajectories over time, thereby enabling the visualization and quantitative analysis of morphological development. To facilitate data exploration, results are plotted dynamically through an interactive Yeast Image Analysis web application (YIMAA; http://yimaa.cs.tut.fi) that integrates the raw and processed images across all time points, allowing exploration of the image-based features and principal components associated with morphological development. PMID:24447135

Ruusuvuori, Pekka; Lin, Jake; Scott, Adrian C.; Tan, Zhihao; Sorsa, Saija; Kallio, Aleksi; Nykter, Matti; Yli-Harja, Olli; Shmulevich, Ilya; Dudley, Aimee M.

2014-01-01

268

Nucleotide degradation and ribose salvage in yeast  

PubMed Central

Nucleotide degradation is a universal metabolic capability. Here we combine metabolomics, genetics and biochemistry to characterize the yeast pathway. Nutrient starvation, via PKA, AMPK/SNF1, and TOR, triggers autophagic breakdown of ribosomes into nucleotides. A protein not previously associated with nucleotide degradation, Phm8, converts nucleotide monophosphates into nucleosides. Downstream steps, which involve the purine nucleoside phosphorylase, Pnp1, and pyrimidine nucleoside hydrolase, Urh1, funnel ribose into the nonoxidative pentose phosphate pathway. During carbon starvation, the ribose-derived carbon accumulates as sedoheptulose-7-phosphate, whose consumption by transaldolase is impaired due to depletion of transaldolase's other substrate, glyceraldehyde-3-phosphate. Oxidative stress increases glyceraldehyde-3-phosphate, resulting in rapid consumption of sedoheptulose-7-phosphate to make NADPH for antioxidant defense. Ablation of Phm8 or double deletion of Pnp1 and Urh1 prevent effective nucleotide salvage, resulting in metabolite depletion and impaired survival of starving yeast. Thus, ribose salvage provides means of surviving nutrient starvation and oxidative stress. PMID:23670538

Xu, Yi-Fan; Letisse, Fabien; Absalan, Farnaz; Lu, Wenyun; Kuznetsova, Ekaterina; Brown, Greg; Caudy, Amy A; Yakunin, Alexander F; Broach, James R; Rabinowitz, Joshua D

2013-01-01

269

[PSI+] Prion Variant Establishment in Yeast  

PubMed Central

Summary Differences in the clinical pathology of mammalian prion diseases reflect distinct heritable conformations of aggregated PrP proteins, called prion strains. Here, using the yeast [PSI+] prion, we examine the de novo establishment of prion strains (called variants in yeast). The [PSI+] prion protein, Sup35, is efficiently induced to take on numerous prion variant conformations following transient overexpression of Sup35 in the presence of another prion, e.g. [PIN+]. One hypothesis is that the first [PSI+] prion seed to arise in a cell causes propagation of only that seed’s variant, but that different variants could be initiated in different cells. However, we now show that even within a single cell, Sup35 retains the potential to fold into more than one variant type. When individual cells segregating different [PSI+] variants were followed in pedigrees, establishment of a single variant phenotype generally occurred in daughters, granddaughters or great granddaughters—but in 5% of the pedigrees cells continued to segregate multiple variants indefinitely. The data is consistent with the idea that many newly formed prions go through a maturation phase before they reach a single specific variant conformation. These findings may be relevant to mammalian PrP prion strain establishment and adaptation. PMID:22998111

Sharma, Jaya; Liebman, Susan W.

2012-01-01

270

Conservation of recombination hotspots in yeast  

PubMed Central

Meiotic recombination does not occur randomly along a chromosome, but instead tends to be concentrated in small regions, known as “recombination hotspots.” Recombination hotspots are thought to be short-lived in evolutionary time due to their self-destructive nature, as gene conversion favors recombination-suppressing alleles over recombination-promoting alleles during double-strand repair. Consistent with this expectation, hotspots in humans are highly dynamic, with little correspondence in location between humans and chimpanzees. Here, we identify recombination hotspots in two lineages of the yeast Saccharomyces paradoxus, and compare their locations to those found previously in Saccharomyces cerevisiae. Surprisingly, we find considerable overlap between the two species, despite the fact that they are at least 10 times more divergent than humans and chimpanzees. We attribute this unexpected result to the low frequency of sex and outcrossing in these yeasts, acting to reduce the population genetic effect of biased gene conversion. Traces from two other signatures of recombination, namely high mutagenicity and GC-biased gene conversion, are consistent with this interpretation. Thus, recombination hotspots are not inevitably short-lived, but rather their persistence through evolutionary time will be determined by the frequency of outcrossing events in the life cycle. PMID:20385822

Tsai, Isheng J.; Burt, Austin; Koufopanou, Vassiliki

2010-01-01

271

Alcohol-mediated haemolysis in yeast.  

PubMed

Although yeast are generally non-haemolytic, we have found that addition of alcohol vapour confers haemolytic properties on many strains of yeast and other fungi. We have called this phenomenon 'microbial alcohol-conferred haemolysis' (MACH). MACH is species- and strain-specific: whereas all six Candida tropicalis strains tested were haemolytic in the presence of ethanol, none among 10 C. glabrata strains tested exhibited this phenomenon. Among 27 C. albicans strains and 11 Saccharomyces cerevisiae strains tested, ethanol-mediated haemolysis was observed in 11 and 4 strains, respectively. Haemolysis is also dependent on the alcohol moiety: n-butanol and n-pentanol could also confer haemolysis, whereas methanol and 2-propanol did not. Haemolysis was found to be dependent on initial oxidation of the alcohol. Reduced haemolysis was observed in specific alcohol dehydrogenase mutants of both Aspergillus nidulans and S. cerevisiae. MACH was not observed during anaerobic growth, and was reduced in the presence of pararosaniline, an aldehyde scavenger. Results suggest that initial oxidation of the alcohol to the corresponding aldehyde is an essential step in the observed phenomenon. PMID:15565638

Shuster, Amir; Osherov, Nir; Rosenberg, Mel

2004-12-01

272

Yeast species associated with wine grapes in China.  

PubMed

Having more information on the yeast ecology of grapes is important for wine-makers to produce wine with high quality and typical attributes. China is a significant wine-consuming country and is becoming a serious wine-producer, but little has been reported about the yeast ecology of local ecosystems. This study provides the first step towards the exploitation of the yeast wealth in China's vine-growing regions. The aim of this study was to investigate the yeast population density and diversity on three grape varieties cultivated in four representative vine-growing regions of China. Yeast species diversity was evaluated by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis of the 5.8S internal transcribed spacer (ITS) ribosomal DNA (rDNA) region of cultivable yeasts. The grapes harbored yeast populations at 10(2)-10(6)CFU/mL, consisting mostly of non-Saccharomyces species. Seventeen different yeast species belonging to eight genera were detected on the grape samples tested, including Hanseniaspora uvarum, Cryptococcus flavescens, Pichia fermentans, Candida zemplinina, Cryptococcus carnescens, Candida inconpicua, Zygosaccharomyces fermentati, Issatchenkia terricola, Candida quercitrusa, Hanseniaspora guilliermondii, Candida bombi, Zygosaccharomyces bailii, Sporidiobolus pararoseus, Cryptococcus magnus, Metschnikowia pulcherrima, Issatchenkia orientalis and Pichia guilliermondii. H. uvarum and C. flavescens were the dominant species present on the grapes. For the first time Sporidiobolus pararoseus was discovered as an inhabitant of the grape ecosystem. The yeast community on grape berries was influenced by the grape chemical composition, vine-variety and vine-growing region. This study is the first to identify the yeast communities associated with grapes in China using molecular methods. The results enrich our knowledge of wine-related microorganisms, and can be used to promote the development of the local wine industry. PMID:20116124

Li, Shuang-Shi; Cheng, Chao; Li, Zheng; Chen, Jing-Yu; Yan, Bin; Han, Bei-Zhong; Reeves, Malcolm

2010-03-31

273

Carrier DNA For Yeast Transformation Preparation of high molecular weight single stranded carrier DNA for yeast transformations.  

E-print Network

with an equal volume of phenol:CHCl3. Centrifuge for 5 minutes to separate layers. 6. Precipitate DNA. Add 1Carrier DNA For Yeast Transformation Preparation of high molecular weight single stranded carrier DNA for yeast transformations. 1. Dissolve 100 mg DNA in 10 ml TE, pH 8 in a sterile 50 ml plastic

Aris, John P.

274

[Historic development of yeast genetics from the beginning to the first gene transformation in brewing yeast strains].  

PubMed

A more intensive use of the potential of brewing yeasts in the biotechnological process of brewing is based on the knowledge of the genetic background of these microorganisms. It is given a review on the stages of genetic manipulation of brewing yeasts including recombinant DNA technology which has proved to be the most successful method for a further improvement of strains. PMID:2672680

Schulz, R

1989-01-01

275

Introducing a New Breed of Wine Yeast: Interspecific Hybridisation between a Commercial Saccharomyces cerevisiae Wine Yeast and Saccharomyces mikatae  

PubMed Central

Interspecific hybrids are commonplace in agriculture and horticulture; bread wheat and grapefruit are but two examples. The benefits derived from interspecific hybridisation include the potential of generating advantageous transgressive phenotypes. This paper describes the generation of a new breed of wine yeast by interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast strain and Saccharomyces mikatae, a species hitherto not associated with industrial fermentation environs. While commercially available wine yeast strains provide consistent and reliable fermentations, wines produced using single inocula are thought to lack the sensory complexity and rounded palate structure obtained from spontaneous fermentations. In contrast, interspecific yeast hybrids have the potential to deliver increased complexity to wine sensory properties and alternative wine styles through the formation of novel, and wider ranging, yeast volatile fermentation metabolite profiles, whilst maintaining the robustness of the wine yeast parent. Screening of newly generated hybrids from a cross between a S. cerevisiae wine yeast and S. mikatae (closely-related but ecologically distant members of the Saccharomyces sensu stricto clade), has identified progeny with robust fermentation properties and winemaking potential. Chemical analysis showed that, relative to the S. cerevisiae wine yeast parent, hybrids produced wines with different concentrations of volatile metabolites that are known to contribute to wine flavour and aroma, including flavour compounds associated with non-Saccharomyces species. The new S. cerevisiae x S. mikatae hybrids have the potential to produce complex wines akin to products of spontaneous fermentation while giving winemakers the safeguard of an inoculated ferment. PMID:23614011

Bellon, Jennifer R.; Schmid, Frank; Capone, Dimitra L.; Dunn, Barbara L.; Chambers, Paul J.

2013-01-01

276

Creation of a novel peptide endowing yeasts with acid tolerance using yeast cell-surface engineering  

Microsoft Academic Search

The cell wall of Saccharomyces cerevisiae plays an essential role in the biophysical characteristics of the cell surface. The modification of the cell wall property\\u000a is an important factor for cellular adaptation to a stressful environment. In this study, we randomly modified the cell wall\\u000a by displaying combinatorial random peptides on the yeast cell surface, and by screening, we successfully

Ken Matsui; Kouichi Kuroda; Mitsuyoshi Ueda

2009-01-01

277

Biosynthesis of Crystalline Silver and Gold Nanoparticles by Extremophilic Yeasts  

PubMed Central

The biosynthesis of Ag and Au nanoparticles (NPs) was investigated using an extremophilic yeast strain isolated from acid mine drainage in Portugal. Three distinct studies were performed, namely, the growth of yeast strain in presence of metal ions, the use of yeast biomass for the metal nanoparticles synthesis, and of the supernatant obtained after 24-hour incubation of yeast biomass in water. The extremophilic strain under study was able to grow up to an Ag ion concentration of 1.5?mM whereas an increase of Au ion concentration over 0.09?mM caused a strong inhibitory effect. A successful route for the metal NPs synthesis was obtained using the yeast biomass. When the washed yeast cells were in contact with Ag or Au solutions, AgNPs smaller than 20?nm were produced, as for the AuNPs diameter ranged from 30 to 100?nm, as determined through transmission electron microscopy and confirmed by energy-dispersive X-ray spectra. The supernatant-based strategy provided evidence that proteins were released to the medium by the yeasts, which could be responsible for the formation and stabilisation of the Ag NPs, although the involvement of the cell wall seems fundamental for AuNPs synthesis. PMID:21912532

Mourato, Ana; Gadanho, Mário; Lino, Ana R.; Tenreiro, Rogério

2011-01-01

278

The beetle gut: a hyperdiverse source of novel yeasts  

PubMed Central

We isolated over 650 yeasts over a three year period from the gut of a variety of beetles and characterized them on the basis of LSU rDNA sequences and morphological and metabolic traits. Of these, at least 200 were undescribed taxa, a number equivalent to almost 30% of all currently recognized yeast species. A Bayesian analysis of species discovery rates predicts further sampling of previously sampled habitats could easily produce another 100 species. The sampled habitat is, thereby, estimated to contain well over half as many more species as are currently known worldwide. The beetle gut yeasts occur in 45 independent lineages scattered across the yeast phylogenetic tree, often in clusters. The distribution suggests that the some of the yeasts diversified by a process of horizontal transmission in the habitats and subsequent specialization in association with insect hosts. Evidence of specialization comes from consistent associations over time and broad geographical ranges of certain yeast and beetle species. The discovery of high yeast diversity in a previously unexplored habitat is a first step toward investigating the basis of the interactions and their impact in relation to ecology and evolution. PMID:15912941

SUH, Sung-Oui; McHUGH, Joseph V.; POLLOCK, David D.; BLACKWELL, Meredith

2010-01-01

279

Characterization of isolated yeast growth response to methionine analogs.  

PubMed

Methionine is one of the first limiting amino acids in poultry nutrition. The use of methionine-rich natural feed ingredients, such as soybean meal or rapeseed meal may lead to negative environmental consequences. Amino acid supplementation leads to reduced use of protein-rich ingredients. The objectives of this study were isolation of potentially high content methionine-containing yeasts, quantification of methionine content in yeasts and their respective growth response to methionine analogs. Minimal medium was used as the selection medium and the isolation medium of methionine-producing yeasts from yeast collection and environmental samples, respectively. Two yeasts previously collected along with six additional strains isolated from Caucasian kefir grains, air-trapped, cantaloupe, and three soil samples could grow on minimal medium. Only two of the newly isolated strains, K1 and C1, grew in minimal medium supplied with either methionine analogs ethionine or norleucine at 0.5% (w/v). Based on large subunit rRNA sequences, these isolated strains were identified as Pichia udriavzevii/Issatchenkia orientalis. P. kudriavzevii/I. orentalis is a generally recognized as a safe organism. In addition, methionine produced by K1 and C1 yeast hydrolysate yielded 1.3 ± 0.01 and 1.1 ± 0.01 mg g(-1) dry cell. Yeast strain K1 may be suitable as a potential source of methionine for dietary supplements in organic poultry feed but may require growth conditions to further increase their methionine content. PMID:24007489

Saengkerdsub, Suwat; Lingbeck, Jody M; Wilkinson, Heather H; O'Bryan, Corliss A; Crandall, Philip G; Muthaiyan, Arunachalam; Biswas, Debabrata; Ricke, Steven C

2013-01-01

280

Fission Yeast Hotspot Sequence Motifs Are Also Active in Budding Yeast  

PubMed Central

In most organisms, including humans, meiotic recombination occurs preferentially at a limited number of sites in the genome known as hotspots. There has been substantial progress recently in elucidating the factors determining the location of meiotic recombination hotspots, and it is becoming clear that simple sequence motifs play a significant role. In S. pombe, there are at least five unique sequence motifs that have been shown to produce hotspots of recombination, and it is likely that there are more. In S. cerevisiae, simple sequence motifs have also been shown to produce hotspots or show significant correlations with hotspots. Some of the hotspot motifs in both yeasts are known or suspected to bind transcription factors (TFs), which are required for the activity of those hotspots. Here we show that four of the five hotspot motifs identified in S. pombe also create hotspots in the distantly related budding yeast S. cerevisiae. For one of these hotspots, M26 (also called CRE), we identify TFs, Cst6 and Sko1, that activate and inhibit the hotspot, respectively. In addition, two of the hotspot motifs show significant correlations with naturally occurring hotspots. The conservation of these hotspots between the distantly related fission and budding yeasts suggests that these sequence motifs, and others yet to be discovered, may function widely as hotspots in many diverse organisms. PMID:23300865

Steiner, Walter W.; Steiner, Estelle M.

2012-01-01

281

Yeast Sequencing Report A 38 kb segment containing the cdc2 gene from the  

E-print Network

Yeast Sequencing Report A 38 kb segment containing the cdc2 gene from the left arm of ®ssion yeast-8566, Japan. E-mail: machida@nibh.go.jp YEAST Yeast 2000; 16: 71±80. Received 3 May 1999 Accepted 18 September

282

Yeast RNase III as a Key Processing Enzyme in Small Nucleolar RNAs Metabolism  

E-print Network

Yeast RNase III as a Key Processing Enzyme in Small Nucleolar RNAs Metabolism Guillaume Chanfreau searched for yeast snoRNAs which are affected by the depletion of the yeast ortholog of bacterial RNase III, Rnt1. In a yeast strain inactivated for RNT1, almost half of the snoRNAs tested are depleted

Chanfreau, Guillaume

283

Production of Dairy-Based, Natural Sulphur Flavor Concentrate by Yeast Fermentation  

Microsoft Academic Search

Production of sulphur flavor concentrate by yeast fermentation was investigated using dairy media (milk and cream) spiked with L-methionine. The yeasts studied included so-called dairy yeasts Candida kefyr, Kluyveromyces marxianus, Debaryomyces hansenii, Geotrichum candidum, and Yarrowia lipolytica as well as wine yeasts Saccharomyces cerevisiae and Saccharomyces bayanus. Methionol was produced as the predominant volatile sulphur flavor compound. Other volatile sulphur

S.-Q. Liu; V. L. Crow

2010-01-01

284

The yeast spectrum of the 'tea fungus Kombucha'.  

PubMed

The tea fungus 'Kombucha' is a symbiosis of Acetobacter, including Acetobacter xylinum as a characteristic species, and various yeasts. A characteristic yeast species or genus has not yet been identified. Kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. In addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, as well as some antibiotic substances. To characterize the yeast spectrum with special consideration given to facultatively pathogenic yeasts, two commercially available specimens of tea fungus and 32 from private households in Germany were analysed by micromorphological and biochemical methods. Yeasts of the genera Brettanomyces, Zygosaccharomyces and Saccharomyces were identified in 56%, 29% and 26% respectively. The species Saccharomycodes ludwigii and Candida kefyr were only demonstrated in isolated cases. Furthermore, the tests revealed pellicle-forming yeasts such as Candida krusei or Issatchenkia orientalis/occidentalis as well as species of the apiculatus yeasts (Kloeckera, Hanseniaspora). Thus, the genus Brettanomyces may be a typical group of yeasts that are especially adapted to the environment of the tea fungus. However, to investigate further the beneficial effects of tea fungus, a spectrum of the other typical genera must be defined. Only three specimens showed definite contaminations. In one case, no yeasts could be isolated because of massive contamination with Penicillium spp. In the remaining two samples (from one household), Candida albicans was demonstrated. The low rate of contamination might be explained by protective mechanisms, such as formation of organic acids and antibiotic substances. Thus, subjects with a healthy metabolism do not need to be advised against cultivating Kombucha. However, those suffering from immunosuppression should preferably consume controlled commercial Kombucha beverages. PMID:8559192

Mayser, P; Fromme, S; Leitzmann, C; Gründer, K

1995-01-01

285

Sporulation in the Budding Yeast Saccharomyces cerevisiae  

PubMed Central

In response to nitrogen starvation in the presence of a poor carbon source, diploid cells of the yeast Saccharomyces cerevisiae undergo meiosis and package the haploid nuclei produced in meiosis into spores. The formation of spores requires an unusual cell division event in which daughter cells are formed within the cytoplasm of the mother cell. This process involves the de novo generation of two different cellular structures: novel membrane compartments within the cell cytoplasm that give rise to the spore plasma membrane and an extensive spore wall that protects the spore from environmental insults. This article summarizes what is known about the molecular mechanisms controlling spore assembly with particular attention to how constitutive cellular functions are modified to create novel behaviors during this developmental process. Key regulatory points on the sporulation pathway are also discussed as well as the possible role of sporulation in the natural ecology of S. cerevisiae. PMID:22084423

Neiman, Aaron M.

2011-01-01

286

Stability of immobilized yeast alcohol dehydrogenase  

SciTech Connect

The effects of substrate on stabilities of native (NA) and three kinds of immobilized yeast alcohol dehydrogenase (IMA), namely PGA (the carrier; porous glass), SEA (agarose gel) prepared covalently, and AMA (anion-exchange resin) prepared ionically, were studied. The following results were obtained. 1) The deactivations of NA and IMA free from the substrate or in the presence of ethanol obey the first-order kinetics, whereas, in the presence of butyraldehyde, their deactivation behaviors are explained on the basis of coexistence of two components of YADHs, namely the labile E1 and the comparatively stable E2, with different first-order deactivation constants. (2) A few attempts for stabilization of IMA were carried out from the viewpoint of the effects of crosslinkages among the subunits of YADH for PGA and the multibonding between the carrier and enzyme for SEA. The former is effective for the stabilization, whereas the latter is not. (Refs. 19).

Ooshima, H.; Genko, Y.; Harano, Y.

1981-12-01

287

Cell population modelling of yeast glycolytic oscillations.  

PubMed Central

We investigated a cell-population modelling technique in which the population is constructed from an ensemble of individual cell models. The average value or the number distribution of any intracellular property captured by the individual cell model can be calculated by simulation of a sufficient number of individual cells. The proposed method is applied to a simple model of yeast glycolytic oscillations where synchronization of the cell population is mediated by the action of an excreted metabolite. We show that smooth one-dimensional distributions can be obtained with ensembles comprising 1000 individual cells. Random variations in the state and/or structure of individual cells are shown to produce complex dynamic behaviours which cannot be adequately captured by small ensembles. PMID:12206713

Henson, Michael A; Müller, Dirk; Reuss, Matthias

2002-01-01

288

Chromosome Dynamics in the Yeast Interphase Nucleus  

NASA Astrophysics Data System (ADS)

Little is known about the dynamics of chromosomes in interphase nuclei. By tagging four chromosomal regions with a green fluorescent protein fusion to lac repressor, we monitored the movement and subnuclear position of specific sites in the yeast genome, sampling at short time intervals. We found that early and late origins of replication are highly mobile in G1 phase, frequently moving at or faster than 0.5 micrometers/10 seconds, in an energy-dependent fashion. The rapid diffusive movement of chromatin detected in G1 becomes constrained in S phase through a mechanism dependent on active DNA replication. In contrast, telomeres and centromeres provide replication-independent constraint on chromatin movement in both G1 and S phases.

Heun, Patrick; Laroche, Thierry; Shimada, Kenji; Furrer, Patrick; Gasser, Susan M.

2001-12-01

289

Modification of yeast ribosomal proteins. Phosphorylation.  

PubMed Central

Two-dimensional polyacrylamide-gel electrophoretic analysis of yeast ribosomal proteins labelled in vivo with 32PO43- revealed that the proteins S2 and S10 of the 40S ribosomal subunit, and the proteins L9, L30, L44 and L45 of the 60S ribosomal subunit, are phosphorylated in vivo. Most of the phosphate groups appeared to be linked to serine residues. Teh number of phosphate groups per molecule of phosphorylated protein species ranged from 0.01 to 0.79. Since most of the phosphorylated ribosomal proteins appear to associate with the pre-ribosomal particles at a very late stage of ribosome assembly, phosphorylation is more likely to play a role in the functioning of the ribosome than in its assembly. Images Fig. 1. Fig. 2. Fig. 3. PMID:367365

Kruiswijk, T; de Hey, J T; Planta, R J

1978-01-01

290

Phyllosphere yeasts rapidly break down biodegradable plastics  

PubMed Central

The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands. PMID:22126328

2011-01-01

291

Debaryomyces hansenii: An Osmotolerant and Halotolerant Yeast  

NASA Astrophysics Data System (ADS)

The yeast Debaryomyces hansenii which was isolated from saline environments such as sea water, concentrated brines, salty food, is one of the most halotolerant species. It can grow in media containing as high as 4 M NaCl, while the growth of Saccharomyces cerevisiae is limited in media with more than 1.7 M NaCl. This species is very important for food industry as it is used for surface ripening of cheese and meat products. In the recent past, there is growing interest in understanding the molecular mechanisms of high halotolerance exhibited by D. hansenii. Availability of genome sequence of D. hansenii has opened up new vistas in this direction

Aggarwal, Monika; Mondal, Alok K.

292

Biofuels. Engineering alcohol tolerance in yeast.  

PubMed

Ethanol toxicity in the yeast Saccharomyces cerevisiae limits titer and productivity in the industrial production of transportation bioethanol. We show that strengthening the opposing potassium and proton electrochemical membrane gradients is a mechanism that enhances general resistance to multiple alcohols. The elevation of extracellular potassium and pH physically bolsters these gradients, increasing tolerance to higher alcohols and ethanol fermentation in commercial and laboratory strains (including a xylose-fermenting strain) under industrial-like conditions. Production per cell remains largely unchanged, with improvements deriving from heightened population viability. Likewise, up-regulation of the potassium and proton pumps in the laboratory strain enhances performance to levels exceeding those of industrial strains. Although genetically complex, alcohol tolerance can thus be dominated by a single cellular process, one controlled by a major physicochemical component but amenable to biological augmentation. PMID:25278607

Lam, Felix H; Ghaderi, Adel; Fink, Gerald R; Stephanopoulos, Gregory

2014-10-01

293

Genotoxicity of selenite in diploid yeast.  

PubMed

Selenite, a chemical of industrial importance and also an antimutagenic/anticarcinogenic agent, was tested for mutagenic and recombinogenic effects in 2 diploid yeast strains, Saccharomyces cerevisiae BZ 34 and D7. Selenite induced gene conversion and toxicity in BZ 34 and a variety of genetic events, viz. back-mutation, gene conversion, mitotic crossing-over, aberrant colony formation and also toxicity in the D7 strain. In both strains, the genetic effects of selenite showed a peak and a decline during 5 h of treatment while its toxicity increased marginally during 1-5 h. In the BZ 34 strain, the presence of glutathione (GSH) during selenite treatment greatly enhanced the convertogenic and toxic effects of selenite. PMID:3280994

Anjaria, K B; Madhvanath, U

1988-04-01

294

Ordering the Final Events in Yeast Exocytosis  

PubMed Central

In yeast, assembly of exocytic soluble N-ethylmaleimide–sensitive fusion protein (NSF) attachment protein receptor (SNARE) complexes between the secretory vesicle SNARE Sncp and the plasma membrane SNAREs Ssop and Sec9p occurs at a late stage of the exocytic reaction. Mutations that block either secretory vesicle delivery or tethering prevent SNARE complex assembly and the localization of Sec1p, a SNARE complex binding protein, to sites of secretion. By contrast, wild-type levels of SNARE complexes persist in the sec1-1 mutant after a secretory block is imposed, suggesting a role for Sec1p after SNARE complex assembly. In the sec18-1 mutant, cis-SNARE complexes containing surface-accessible Sncp accumulate in the plasma membrane. Thus, one function of Sec18p is to disassemble SNARE complexes on the postfusion membrane. PMID:11038189

Grote, Eric; Carr, Chavela M.; Novick, Peter J.

2000-01-01

295

Unsuspected pyocyanin effect in yeast under anaerobiosis.  

PubMed

The blue-green phenazine, Pyocyanin (PYO), is a well-known virulence factor produced by Pseudomonas aeruginosa, notably during cystic fibrosis lung infections. It is toxic to both eukaryotic and bacterial cells and several mechanisms, including the induction of oxidative stress, have been postulated. However, the mechanism of PYO toxicity under the physiological conditions of oxygen limitation that are encountered by P. aeruginosa and by target organisms in vivo remains unclear. In this study, wild-type and mutant strains of the yeast Saccharomyces cerevisiae were used as an effective eukaryotic model to determine the toxicity of PYO (100-500 ?mol/L) under key growth conditions. Under respiro-fermentative conditions (with glucose as substrate), WT strains and certain H2 O2 -hypersensitive strains showed a low-toxic response to PYO. Under respiratory conditions (with glycerol as substrate) all the strains tested were significantly more sensitive to PYO. Four antioxidants were tested but only N-acetylcysteine was capable of partially counteracting PYO toxicity. PYO did not appear to affect short-term respiratory O2 uptake, but it did seem to interfere with cyanide-poisoned mitochondria through a complex III-dependent mechanism. Therefore, a combination of oxidative stress and respiration disturbance could partly explain aerobic PYO toxicity. Surprisingly, the toxic effects of PYO were more significant under anaerobic conditions. More pronounced effects were observed in several strains including a 'petite' strain lacking mitochondrial DNA, strains with increased or decreased levels of ABC transporters, and strains deficient in DNA damage repair. Therefore, even though PYO is toxic for actively respiring cells, O2 may indirectly protect the cells from the higher anaerobic-linked toxicity of PYO. The increased sensitivity to PYO under anaerobic conditions is not unique to S. cerevisiae and was also observed in another yeast, Candida albicans. PMID:24307284

Barakat, Rana; Goubet, Isabelle; Manon, Stephen; Berges, Thierry; Rosenfeld, Eric

2014-02-01

296

Unsuspected pyocyanin effect in yeast under anaerobiosis  

PubMed Central

The blue–green phenazine, Pyocyanin (PYO), is a well-known virulence factor produced by Pseudomonas aeruginosa, notably during cystic fibrosis lung infections. It is toxic to both eukaryotic and bacterial cells and several mechanisms, including the induction of oxidative stress, have been postulated. However, the mechanism of PYO toxicity under the physiological conditions of oxygen limitation that are encountered by P. aeruginosa and by target organisms in vivo remains unclear. In this study, wild-type and mutant strains of the yeast Saccharomyces cerevisiae were used as an effective eukaryotic model to determine the toxicity of PYO (100–500??mol/L) under key growth conditions. Under respiro-fermentative conditions (with glucose as substrate), WT strains and certain H2O2-hypersensitive strains showed a low-toxic response to PYO. Under respiratory conditions (with glycerol as substrate) all the strains tested were significantly more sensitive to PYO. Four antioxidants were tested but only N-acetylcysteine was capable of partially counteracting PYO toxicity. PYO did not appear to affect short-term respiratory O2 uptake, but it did seem to interfere with cyanide-poisoned mitochondria through a complex III-dependent mechanism. Therefore, a combination of oxidative stress and respiration disturbance could partly explain aerobic PYO toxicity. Surprisingly, the toxic effects of PYO were more significant under anaerobic conditions. More pronounced effects were observed in several strains including a ‘petite’ strain lacking mitochondrial DNA, strains with increased or decreased levels of ABC transporters, and strains deficient in DNA damage repair. Therefore, even though PYO is toxic for actively respiring cells, O2 may indirectly protect the cells from the higher anaerobic-linked toxicity of PYO. The increased sensitivity to PYO under anaerobic conditions is not unique to S. cerevisiae and was also observed in another yeast, Candida albicans. PMID:24307284

Barakat, Rana; Goubet, Isabelle; Manon, Stephen; Berges, Thierry; Rosenfeld, Eric

2014-01-01

297

[Isolation and characterization of lactose-fermenting yeasts Candida kefyr].  

PubMed

The search for lactose-fermenting yeast strains has been conducted among 162 strains isolated from various plants and 28 yeast strains isolated from cheese. Four yeast strains have been shown to ferment lactose. They have been identified as Candida kefyr. Specific beta-galactosidase activity of the studied strains grown on lactose-containing medium was 1501-2113 U/g cell. The ethanol production by strains C. kefyr C24 and C30 was significantly inhibited by the increase in substrate concentration (100 g/l). PMID:24437197

Ianieva, O D; Voronina, H O; Pidhors'ky?, V S

2013-01-01

298

Charcoal-Yeast Extract Agar: Primary Isolation Mediumfor Legionella pneumophila  

Microsoft Academic Search

Charcoal-yeast extract agar isa new bacteriological mediumthatsupports excellent growth oftheLegionella pneumophila. Itresults frommodifications madeinan existing L.pneumophila medium,F-Gagar.Yeastextract, instead of an acidhydrolysate ofcasein, servesastheprotein source.Beefextractives and starch are notadded. Activated charcoal (Norit A or Norit SG)isincluded at 0.20%(wt\\/vol). Comparison ofcharcoal-yeast extract andF-Gagars showedthat a greater numberofcolony-forming units ofL.pneumophila was recovered from astandardized tissue inoculum on charcoal-yeast extract agar(4.35 x 106colony- forning

JAMES C. FEELEY; ROBERT J. GIBSON; GEORGE W. GORMAN; NANCY C. LANGFORD; J. KAMILE RASHEED; DON C. MACKEL; WILLIAM B. BAINE

1979-01-01

299

Expression of the Maize Mnsod (Sod3) Gene in Mnsod-Deficient Yeast Rescues the Mutant Yeast under Oxidative Stress  

PubMed Central

Superoxide dismutases (SOD) are ubiquitous in aerobic organisms and are believed to play a significant role in protecting cells against the toxic, often lethal, effect of oxygen free radicals. However, direct evidence that SOD does in fact participate in such a protective role is scant. The MnSOD-deficient yeast strain (Sod2d) offered an opportunity to test the functional role of one of several SOD isozymes from the higher plant maize in hopes of establishing a functional bioassay for other SODs. Herein, we present evidence that MnSOD functions to protect cells from oxidative stress and that this function is conserved between species. The maize Sod3 gene was introduced into the yeast strain Sod2d where it was properly expressed and its product processed into the yeast mitochondrial matrix and assembled into the functional homotetramer. Most significantly, expression of the maize Sod3 transgene in yeast rendered the transformed yeast cells resistant to paraquat-induced oxidative stress by complementing the MnSOD deficiency. Furthermore, analyses with various deletion mutants of the maize SOD-3 transit peptide in the MnSOD-deficient yeast strain indicate that the initial portion (about 8 amino acids) of the maize transit peptide is required to direct the protein into the yeast mitochondrial matrix in vivo to function properly. These findings indicate that the functional role of maize MnSOD is conserved and dependent on its proper subcellular location in the mitochondria of a heterologous system. PMID:1516816

Zhu, D.; Scandalios, J. G.

1992-01-01

300

Construction of a large synthetic human Fab antibody library on yeast cell surface by optimized yeast mating.  

PubMed

Yeast surface-displayed antibody libraries provide an efficient and quantitative screening resource for given antigens, but suffer from typically modest library sizes owing to low yeast transformation efficiency. Yeast mating is an attractive method for overcoming the limit of yeast transformation to construct a large, combinatorial antibody library, but the optimal conditions have not been reported. Here, we report a large synthetic human Fab (antigen binding fragment) yeast surface-displayed library generated by stepwise optimization of yeast mating conditions. We first constructed HC (heavy chain) and LC (light chain) libraries, where all of the six CDRs (complementarity-determining regions) of the variable domains were diversified mimicking the human germline antibody repertoires by degenerate codons, onto single frameworks of VH3-23 and Vkappa1-16 germline sequences, in two haploid cells of opposite mating types. Yeast mating conditions were optimized in the order of cell density, media pH, and cell growth phase, yielding a mating efficiency of ~58% between the two haploid cells carrying HC and LC libraries. We constructed two combinatorial Fab libraries with CDR-H3 of 9 or 11 residues in length with colony diversities of more than 10(9) by one round of yeast mating between the two haploid HC and LC libraries, with modest diversity sizes of ~10(7). The synthetic human Fab yeast-displayed libraries exhibited relative amino acid compositions in each position of the six CDRs that were very similar to those of the designed repertoires, suggesting that they are a promising source for human Fab antibody screening. PMID:24394194

Baek, Du-San; Kim, Yong-Sung

2014-03-28

301

Plating Yeast Colonies 1. Swirl 1 colony (0.5 -2 mm diameter) into 1 ml sterile dH2O with toothpick (faintly turbid).  

E-print Network

78 Plating Yeast Colonies 1. Swirl 1 colony (0.5 - 2 mm diameter) into 1 ml sterile dH2O. Undiluted Cells (2nd column from left is best) Yeast Strain #1 Yeast Strain #2 Yeast Strain #3 Yeast Strain #4 Yeast Strain #5 Yeast Strain #6 10X Dilution Series Replica plating samples without serial

Aris, John P.

302

Organoleptic Analysis of Doughs Fermented with Yeasts From A Nigerian Palm Wine (Elaeis guineensis) and Certain Commercial Yeasts  

PubMed Central

Yeasts isolated from a freshly tapped palm wine obtained from Akure, Nigeria were identified as Schizosaccharomyces pombe, Saccharomyces cerevisiae, Debaryomyces hansenii, Geotrichum lactis and Zygosaccharomyces rouxii. Each of the isolates was used to ferment wheat flour dough and baked. Sensory analysis of the doughs was carried out on leavening, texture, aroma, taste and appearance. Saccharomyces cerevisiae performed best in leavening the dough while Debaryomyces hansenii produced doughs with the best taste and aroma. Appearances of the doughs made with all the isolated yeasts did not differ significantly (P<0.05) from that of the dough that lacked yeast. PMID:19088921

B, Boboye; I, Dayo-Owoyemi; F. A, Akinyosoye

2008-01-01

303

The influence of exogenous nutrients on the abundance of yeasts on the phylloplane of turfgrass.  

PubMed

Four experiments were conducted to assess the effect of foliar applications of various nutrient solutions on the phylloplane yeast community of tall fescue (Festuca arundinacea Schreb.). In the first three experiments, increasing concentrations of sucrose (2-16%), yeast extract (0.5-2.5%), and sucrose plus yeast extract (2.5-18.5% total) were applied and the yeast colony forming units (cfu) enumerated 14 h later by dilution plating. Significant positive linear relationships were observed between the number of yeast cfu and applications of both yeast extract and sucrose plus yeast extract. Foliar applications of sucrose alone had no significant effect on yeast community abundance, indicating that phylloplane yeasts of turfgrass are not limited by the amount or availability of carbohydrates. In the fourth experiment, five different solutions were applied to tall fescue to investigate the response of the yeast community to organic and inorganic nitrogen sources. Tryptone or yeast extract, both with considerable amino acid composition, significantly increased the yeast population, while yeast nitrogen base (with or without amino acids) and ammonium sulfate had no affect on yeast abundance. These results suggest that organic nitrogen stimulate yeast community growth and development on the phylloplane of tall fescue, while carbohydrates, inorganic nitrogen, and non-nitrogenous nutrients have little positive effect. PMID:17487523

Nix-Stohr, Shannon; Burpee, Leon L; Buck, James W

2008-01-01

304

21 CFR 172.898 - Bakers yeast glycan.  

Code of Federal Regulations, 2010 CFR

...the yeast, Saccharomyces cerevisiae. It is composed principally of long chain carbohydrates, not less than 85 percent on a dry solids basis. The carbohydrate is composed of glycan and mannan units in approximately a 2:1 ratio....

2010-04-01

305

21 CFR 172.898 - Bakers yeast glycan.  

Code of Federal Regulations, 2013 CFR

...the yeast, Saccharomyces cerevisiae. It is composed principally of long chain carbohydrates, not less than 85 percent on a dry solids basis. The carbohydrate is composed of glycan and mannan units in approximately a 2:1 ratio....

2013-04-01

306

21 CFR 172.898 - Bakers yeast glycan.  

Code of Federal Regulations, 2012 CFR

...the yeast, Saccharomyces cerevisiae. It is composed principally of long chain carbohydrates, not less than 85 percent on a dry solids basis. The carbohydrate is composed of glycan and mannan units in approximately a 2:1 ratio....

2012-04-01

307

21 CFR 172.898 - Bakers yeast glycan.  

Code of Federal Regulations, 2011 CFR

...the yeast, Saccharomyces cerevisiae. It is composed principally of long chain carbohydrates, not less than 85 percent on a dry solids basis. The carbohydrate is composed of glycan and mannan units in approximately a 2:1 ratio....

2011-04-01

308

21 CFR 172.898 - Bakers yeast glycan.  

...the yeast, Saccharomyces cerevisiae. It is composed principally of long chain carbohydrates, not less than 85 percent on a dry solids basis. The carbohydrate is composed of glycan and mannan units in approximately a 2:1 ratio....

2014-04-01

309

Architecture and evolutionary stability of yeast signaling pathways  

E-print Network

I have researched the effect that selection for the function of the High Osmolarity Glycerol (HOG) pathway has on the evolutionary stability of the pheromone response pathway in the yeast Saccharomyces cerevisiae. I first ...

Gritton, Jeffrey S

2006-01-01

310

Oxidative Stress and Programmed Cell Death in Yeast  

PubMed Central

Yeasts, such as Saccharomyces cerevisiae, have long served as useful models for the study of oxidative stress, an event associated with cell death and severe human pathologies. This review will discuss oxidative stress in yeast, in terms of sources of reactive oxygen species (ROS), their molecular targets, and the metabolic responses elicited by cellular ROS accumulation. Responses of yeast to accumulated ROS include upregulation of antioxidants mediated by complex transcriptional changes, activation of pro-survival pathways such as mitophagy, and programmed cell death (PCD) which, apart from apoptosis, includes pathways such as autophagy and necrosis, a form of cell death long considered accidental and uncoordinated. The role of ROS in yeast aging will also be discussed. PMID:22737670

Farrugia, Gianluca; Balzan, Rena

2012-01-01

311

Transcriptional regulatory network for sexual differentiation in fission yeast  

E-print Network

Abstract Background Changes in gene expression are hallmarks of cellular differentiation. Sexual differentiation in fission yeast (Schizosaccharomyces pombe) provides a model system for gene expression programs accompanying and driving cellular...

Mata, Juan; Wilbrey, Anna; Bahler, Jurg

2007-10-10

312

Supplementary information for: Gene Expression Divergence in Yeast is Coupled  

E-print Network

-axis). Figure S2. The DNA-encoded nucleosome organization of cellular respiration promoters has diverged between1 Supplementary information for: Gene Expression Divergence in Yeast is Coupled to Evolution of DNA

Lieb, Jason

313

PHYLOGENY OF PHOSPHOMANNAN-PRODUCING YEASTS I. The Genera  

PubMed Central

Wickerham, Lynferd J. (U. S. Department of Agriculture, Peoria, Ill.), and Kermit A. Burton. Phylogeny of phosphomannan-producing yeasts. I. The genera. J. Bacteriol. 82:265–268. 1961.—Primitive yeasts of the genera Hansenula, Pichia, and Pachysolen produce extracellular phosphorylated mannans. The phosphomannans cause adherence of the cells to bark beetles that transport the yeasts from the sap-conducting tissues of one tree to another. Two yeasts that produce phosphomannans most abundantly are the most primitive species of Hansenula; H. holstii is heterothallic, and H. capsulata is homothallic. From these two species issued lines of species developing toward independence from trees as their habitat and other lines that developed toward greater dependence upon trees. Most of the primitive species of Pichia are very similar to those species of Hansenula that are highly dependent upon trees. The one available species of Pachysolen resembles species of the less dependent lines. PMID:13785001

Wickerham, Lynferd J.; Burton, Kermit A.

1961-01-01

314

Evolutionary principles of modular gene regulation in yeasts  

E-print Network

Divergence in gene regulation can play a major role in evolution. Here, we used a phylogenetic framework to measure mRNA profiles in 15 yeast species from the phylum Ascomycota and reconstruct the evolution of their modular ...

Thompson, Dawn A.

315

Variable flocculation profiles of yeast strains isolated from cachaça distilleries.  

PubMed

In cachaça production, the use of yeast cells as starters with predictable flocculation behavior facilitates the cell recovery at the end of each fermentation cycle. Therefore, the aim of this work was to explain the behavior of cachaça yeast strains in fermentation vats containing sugarcane through the determination of biochemical and molecular parameters associated with flocculation phenotypes. By analyzing thirteen cachaça yeast strains isolated from different distilleries, our results demonstrated that neither classic biochemical measurements (e.g., percentage of flocculation, EDTA sensitivity, cell surface hydrophobicity, and sugar residues on the cell wall) nor modern molecular approaches, such as polymerase chain reaction (PCR) and real-time PCR (q-PCR), were sufficient to distinctly classify the cachaça yeast strains according to their flocculation behavior. It seems that flocculation is indeed a strain-specific phenomenon that is difficult to explain and/or categorize by the available methodologies. PMID:25209588

Alvarez, Florencia; Correa, Lygia Fátima da Mata; Araújo, Thalita Macedo; Mota, Bruno Eduardo Fernandes; da Conceição, Luís Eduardo F Ribeiro; Castro, Ieso de Miranda; Brandão, Rogelio Lopes

2014-11-01

316

An Analysis of Interference in the Fission Yeast Schizosaccharomyces Pombe  

PubMed Central

The evaluation of three-point crosses at the tetrad and random spore level leads to the conclusion that both chiasma and chromatid interference are absent in the fission yeast Schizosaccharomyces pombe. PMID:8088515

Munz, P.

1994-01-01

317

THE UPTAKE OF AROMATIC AND BRANCHED CHAIN HYDROCARBONS BY YEAST  

EPA Science Inventory

Studies of the hydrocarbon utilizing yeasts, Candida maltosa and C. lipolytica, have shown that both were capable of reducing recoverable amounts of branched chain and aromatic hydrocarbons in a mixture of naphthalene, tetradecane, hexadecane, pristane (tetra-methylpentadecane). ...

318

Dissecting the spatial structure of overlapping transcription in budding yeast  

E-print Network

This thesis presents a computational and algorithmic method for the analysis of high-resolution transcription data in the budding yeast Saccharomyces cerevisiae. We begin by describing a computational system for storing ...

Danford, Timothy W. (Timothy William), 1979-

2010-01-01

319

Comparative study on the identification of food-borne yeasts.  

PubMed Central

Morphologically distinct yeast colonies from partially and fully processed fruits and vegetables were isolated over a 3-year period. Identification of 239 strains was achieved by using standard methods, commercial identification kits (API 20C and API YEAST-IDENT), and a simplified system for food-borne yeasts. The identified strains of fruit origin represented 36 species belonging to 19 genera. Among strains of vegetable origin, 34 species representing 17 genera were identified. The simplified identification system and the conventional method provided the same results in 80% of the cases. The commercial identification kits were easy to use but were not appropriate for food-borne yeast species. Computer-assisted identification was helpful. PMID:2059042

Torok, T; King, A D

1991-01-01

320

Integrative selection of human chromosome-specific yeast artificial chromosomes  

SciTech Connect

Human specific integrative selection vectors (ISVs) were designed to optimize integration of a yeast-selectable marker specifically into yeast artificial chromosomes (YACs) derived from human but not mouse DNA. ISVs were transformed into a YAC genomic library constructed from DNA of a human-mouse somatic cell hybrid containing chromosome 21 (HSA21) as the only human chromosome. One percent of the yeast in the original library contained HSA21-derived YACs; between 45% and 54% of the yeast recovered after transformation with ISV vectors contained human YACs. Integrative selection provides a rapid means of obtaining a highly enriched population of human chromosome-specific YACs by eliminating the labor-intensive steps of isolating and screening primary transformants. The procedure is biased toward the selection of YACs that contain a large number of targets for homologous recombination; thus, libraries constructed by this procedure will be composed primarily of the largest YACs in the population.

Pavan, W.J.; Reeves, R.G. (Johns Hopkins Univ., Baltimore, MD (United States))

1991-09-01

321

Revision of the oligosaccharide structures of yeast carboxypeptidase Y  

SciTech Connect

The N-linked oligosaccharides from baker's yeast carboxypeptidase Y were analyzed by {sup 1}H NMR and specific mannosidase digestion and found to be identical to those from the Saccharomyces cerevisiae mnn9 mutant bulk mannoprotein. The results support the view that the mnn mutants make oligosaccharides that are a true reflection of the normal biosynthetic pathway and confirm that a recently revised yeast oligosaccharide structure is applicable to wild-type mannoproteins.

Ballou, L.; Hernandez, L.M.; Alvarado, E.; Ballou, C.E. (Univ. of California, Berkeley (USA))

1990-05-01

322

Comparison of spontaneous and adaptive mutation spectra in yeast  

Microsoft Academic Search

Adaptive mutations occur in nongrowing populations of cells to overcome strong, nonlethal selection conditions. Several models\\u000a have been proposed for the molecular mechanism(s) for this phenomenon inEscherichia coli, but the mechanisms involved in adaptive mutagenesis in the yeastSaccharomyces cerevisiae are largely unknown. We present here a comparison of the mutational spectra of spontaneous and adaptive frameshift reversion\\u000a events in yeast.

Christopher N. Greene; Sue Jinks-Robertson

1999-01-01

323

Yeast as a model for ageing and apoptosis research  

Microsoft Academic Search

\\u000a Apoptosis is a form of programmed cell death with a crucial role in health and disease in metazoans. Recent findings demonstrate\\u000a the existence of an apoptotic program also in unicellular eukaryotes. Oxygen stress as well as the expression of several conserved\\u000a proapoptotic genes induce the apoptotic pathway in mammalian cells and yeast cells. The dying yeast cells show diagnostic\\u000a markers

Michael Breitenbach; Frank Madeo; Peter Laun; Gino Heeren; Stefanie Jarolim; Kai-Uwe Fröhlich; Silke Wissing; Alena Pichova

324

Diversity of Soil Yeasts Isolated from South Victoria Land, Antarctica  

Microsoft Academic Search

Unicellular fungi, commonly referred to as yeasts, were found to be components of the culturable soil fungal population in\\u000a Taylor Valley, Mt. Discovery, Wright Valley, and two mountain peaks of South Victoria Land, Antarctica. Samples were taken\\u000a from sites spanning a diversity of soil habitats that were not directly associated with vertebrate activity. A large proportion\\u000a of yeasts isolated in

L. Connell; R. Redman; S. Craig; G. Scorzetti; M. Iszard; R. Rodriguez

2008-01-01

325

Mitochondrial DNA size diversity in the Dekkera\\/Brettanomyces yeasts  

Microsoft Academic Search

Restriction endonuclease digestion of mitocondrial DNAs from the nine Dekkera\\/Brettanomyces yeasts have revealed that three separate pairs of species, namely D. bruxellensis\\/B. lambicus; B. abstinens\\/B. custersii and B. anomalus\\/B. clausenii have identical genomes. This observation suggests that such analysis of mtDNA could be an important procedure for yeast taxonomy. Sizes of mtDNAs showed a graded range from the 28 kbp

C. R. McArthur; G. D. Clark-Walker

1983-01-01

326

Exploration of sulfur metabolism in the yeast Kluyveromyces lactis  

Microsoft Academic Search

Hemiascomycetes are separated by considerable evolutionary distances and, as a consequence, the mechanisms involved in sulfur\\u000a metabolism in the extensively studied yeast, Saccharomyces cerevisiae, could be different from those of other species of the phylum. This is the first time that a global view of sulfur metabolism\\u000a is reported in the biotechnological yeast Kluyveromyces lactis. We used combined approaches based

Agnès Hébert; Marie-Pierre Forquin-Gomez; Aurélie Roux; Julie Aubert; Christophe Junot; Valentin Loux; Jean-François Heilier; Pascal Bonnarme; Jean-Marie Beckerich; Sophie Landaud

327

Production of volatile organic sulfur compounds (VOSCs) by basidiomycetous yeasts  

Microsoft Academic Search

Thirty-seven basidiomycetous yeasts belonging to 30 species of seven genera were grown on media containing l-cysteine or l-methionine as sole nitrogen sources with the objective of evaluating volatile organic sulfur compound (VOSC) production. The headspace of yeast cultures was analyzed by the solid-phase microextraction (SPME) sampling method, and volatile compounds were quantified and identified by GC-MS techniques. Ten strains assimilating

Pietro Buzzini; Sergio Romano; Benedetta Turchetti; Ann Vaughan; Ugo Maria Pagnoni; Paolo Davoli

2005-01-01

328

Sterol Esterification in Yeast: A Two-Gene Process  

Microsoft Academic Search

Unesterified sterol modulates the function of eukaryotic membranes. In human cells, sterol is esterified to a storage form by acyl-coenzyme A (CoA): cholesterol acyl transferase (ACAT). Here, two genes are identified, ARE1 and ARE2, that encode ACAT-related enzymes in yeast. The yeast enzymes are 49 percent identical to each other and exhibit 23 percent identity to human ACAT. Deletion of

Hongyuan Yang; Martin Bard; Debora A. Bruner; Anne Gleeson; Richard J. Deckelbaum; Gordana Aljinovic; Thomas M. Pohl; Rodney Rothstein; Stephen L. Sturley

1996-01-01

329

Reduction of volatile acidity of wines by selected yeast strains  

Microsoft Academic Search

Herein, we isolate and characterize wine yeasts with the ability to reduce volatile acidity of wines using a refermentation\\u000a process, which consists in mixing the acidic wine with freshly crushed grapes or musts or, alternatively, in the incubation\\u000a with the residual marc. From a set of 135 yeast isolates, four strains revealed the ability to use glucose and acetic acid

A. Vilela-Moura; D. Schuller; A. Mendes-Faia; M. Côrte-Real

2008-01-01

330

Biochemical characterization and growth patterns of new yeast isolates.  

PubMed

African sorghum opaque beers play a vital role in the diet of millions of consumers. In the current study we investigated the growth profiles of yeast strains isolated from kpete-kpete, a traditional starter used to produce tchoukoutou, an opaque sorghum beer in Benin. 10 yeast strains were isolated from sorghum beer starters and cultivated under both liquid and solid media for phenotypic growth characterization. All yeast isolates were able to grow both on solid and liquid media. Based on their growth profiles, the isolates were clustered into three groups: (i) the aggressive growth pattern (30%), (ii) the moderate growth pattern (50%), and (iii) the slow growth pattern (20%). Based on gene expression pattern, absorbance (A(600 nm)) and diameter of growth in both liquid and solid media respectively, yeast strains YK34, YK15 and YK48 were clustered in the first group, and referred to as the most aggressive growth strains, followed by group 2 (YK24, YK5, YK12, YK20, YK2) and group 3 (YK37, YK41). This growth pattern was confirmed by Invertase gene expression profiling of the yeasts showing group 1 with high level of Invertase gene expression followed by group 2 and group 3 respectively. Our results suggest that YK34, YK15 and YK48 and YK2 yeast strains constitute the best candidates in fermentation of sorghum beer production based on growth rate and assimilation of carbon and nitrogen sources. PMID:24802797

Djegui, Kadjogbé Y; Gachomo, Emma W; Hounhouigan, Djidjoho J; Kayodé, Adéchola P P; Kotchoni, Simeon O

2014-08-01

331

Plant farnesyltransferase can restore yeast Ras signaling and mating  

SciTech Connect

Farnesyltransferase (FTase) is a heterodimeric enzyme that modifies a group of proteins, including Ras, in mammals and yeasts. Plant FTase {alpha} and {beta} subunits were cloned from tomato and expressed in the yeast Saccharomyces cerevisiae to assess their functional conservation in farnesylating Ras and a-factor proteins, which are important for cell growth and mating. The tomato FTase {beta} subunit (LeFTB) alone was unable to complement the growth defect of ram1{del} mutant yeast strains in which the chromosomal FTase {beta} subunit gene was deleted, but coexpression of LeFTB with the plant {alpha} subunit gene (LeFTA) restored normal growth, Ras membrane association, and mating. LeFTB contains a novel 66-amino-acid sequence domain whose deletion reduces the efficiency of tomato FTase to restore normal growth to yeast ram1{del} strains. Coexpression of LeFTA and LeFTB in either yeast or insect cells yielded a functional enzyme that correctly farnesylated CaaX-motif-containing peptides. Despite their low degree of sequence homology, yeast and plant FTases shared similar in vivo and in vitro substrate specificities, demonstrating that this enzymatic modification of proteins with intermediates from the isoprenoid biosynthesis pathway is conserved in evolutionarily divergent eukaryotes. 56 refs., 7 figs., 1 tab.

Yalovsky, S.; Callan, K.L.; Narita, J.O. [Univ. of California, Berkeley, CA (United States)] [and others

1997-04-01

332

Electric field-induced effects on yeast cell wall permeabilization.  

PubMed

The permeability of the yeast cells (Saccharomyces cerevisiae) to lipophilic tetraphenylphosphonium cations (TPP(+) ) after their treatment with single square-shaped strong electric field pulses was analyzed. Pulsed electric fields (PEF) with durations from 5 to 150?µs and strengths from 0 to 10?kV/cm were applied to a standard electroporation cuvette filled with the appropriate buffer. The TPP(+) absorption process was analyzed using an ion selective microelectrode (ISE) and the plasma membrane permeability was determined by measurements obtained using a calcein blue dye release assay. The viability of the yeast and the inactivation of the cells were determined using the optical absorbance method. The experimental data taken after yeasts were treated with PEF and incubated for 3?min showed an increased uptake of TPP(+) by the yeast. This process can be controlled by setting the amplitude and pulse duration of the applied PEF. The kinetics of the TPP(+) absorption process is described using the second order absolute rate equation. It was concluded that the changes of the charge on the yeast cell wall, which is the main barrier for TPP(+) , is due to the poration of the plasma membrane. The applicability of the TPP(+) absorption measurements for the analysis of yeast cells electroporation process is also discussed. PMID:24203648

Stirke, Arunas; Zimkus, Aurelijus; Ramanaviciene, Almira; Balevicius, Saulius; Zurauskiene, Nerija; Saulis, Gintautas; Chaustova, Larisa; Stankevic, Voitech; Ramanavicius, Arunas

2014-02-01

333

Viricidal Effects of Lactobacillus and Yeast Fermentation  

PubMed Central

The survival of selected viruses in Lactobacillus- and yeast-fermented edible waste material was studied to determine the feasibility of using this material as a livestock feed ingredient. Five viruses, including Newcastle disease virus, infectious canine hepatitis virus, a porcine picornavirus, frog virus 3, and bovine virus diarrhea, were inoculated into a mixture of ground food waste (collected from a school lunch program) containing Lactobacillus acidophilus. Mixtures were incubated at 20, 30, and 40°C for 216 h. In a second trial, four viruses, including Newcastle disease virus, infectious canine hepatitis virus, frog virus 3, and a porcine picornavirus, were inoculated into similar edible waste material containing Saccharomyces cerevisiae. Mixtures were incubated at 20 and 30°C for 216 h. Samples were obtained daily for quantitative (trial 1) and qualitative (trial 2) virus isolation. Temperature, pH, and redox potential were monitored. Controlled pH and temperature studies were also done and compared with the inactivation rates in the fermentation processes. In trial 1 (Lactobacillus fermentation), infectious canine hepatitis virus survived the entire test period in the fermentation process but was inactivated below pH 4.5 in the controlled studies. Newcastle disease virus was inactivated by day 8 in the fermentation process and appeared to be primarily heat sensitive and secondarily pH sensitive in the controlled studies. The porcine picornavirus survived the fermentation process for 8 days at 20°C but was inactivated more rapidly at 30 and 40°C. The controlled studies verified these findings. Frog virus 3 was inactivated by day 3 in the fermentation process and appeared to be sensitive to low pH in the controlled studies. Bovine virus diarrhea was rapidly inactivated in the fermentation process (less than 2 h) and was pH and temperature sensitive. In trial 2 (yeast fermentation), infectious hepatitis virus survived the entire test period in the fermentation process. Newcastle disease virus was inactivated by day 7 at 20°C and day 6 at 30°C. The porcine picornavirus was inactivated by day 7 at 30°C but survived the entire test period at 20°C. Frog virus 3 was inactivated by day 3 at 20°C and day 2 at 30°C. PMID:6414372

Gilbert, Jeannine P.; Wooley, Richard E.; Shotts, Emmett B.; Dickens, J. Andra

1983-01-01

334

YEAST VOL.10 1211-1216 (1994) o0 IV '00 Yeast SequencingReports  

E-print Network

. Yeast strains. Strain Genotype DBY1707 DBY1918 MATa sad-1 ura3-52 DBY5381 MATa leu2-3,112 lys2-801 Asac2::LEU2 DBY5393 DBY5395 MATala leu2-3,112lleu2-3,112ura3-52lura3-52 lys2-8011+ MATala leu2-3,I12lleu2-3,112ura3-52lura3-52 lys2-801/+ Asac2::LEU21+ MATa actl-1 ade2 leu2-3,112 TUB2::URA3 ura3-52 (1974). Cold

Botstein, David

335

Cellular functions of cardiolipin in yeast.  

PubMed

Cardiolipin (CL), the signature lipid of mitochondria, plays a critical role in mitochondrial function and biogenesis. The availability of yeast mutants blocked in CL synthesis has facilitated studies of the biological role of this lipid. Perturbation of CL synthesis leads to growth defects not only during respiratory growth but also under conditions in which respiration is not essential. CL was shown to play a role in mitochondrial protein import, cell wall biogenesis, aging and apoptosis, ceramide synthesis, and translation of electron transport chain components. The genetic disorder Barth syndrome (BTHS) is caused by mutations in the tafazzin gene resulting in decreased total CL levels, accumulation of monolysocardiolipin (MLCL), and decreased unsaturated fatty acyl species of CL. The variation in clinical presentation of BTHS indicates that other physiological factors play a significant role in modifying the phenotype resulting from tafazzin deficiency. Elucidating the functions of CL is expected to shed light on the role of this important lipid in BTHS and other disorders of mitochondrial dysfunction. PMID:18725250

Joshi, Amit S; Zhou, Jingming; Gohil, Vishal M; Chen, Shuliang; Greenberg, Miriam L

2009-01-01

336

Pulsatile dynamics in the yeast proteome.  

PubMed

The activation of transcription factors in response to environmental conditions is fundamental to cellular regulation. Recent work has revealed that some transcription factors are activated in stochastic pulses of nuclear localization, rather than at a constant level, even in a constant environment [1-12]. In such cases, signals control the mean activity of the transcription factor by modulating the frequency, duration, or amplitude of these pulses. Although specific pulsatile transcription factors have been identified in diverse cell types, it has remained unclear how prevalent pulsing is within the cell, how variable pulsing behaviors are between genes, and whether pulsing is specific to transcriptional regulators or is employed more broadly. To address these issues, we performed a proteome-wide movie-based screen to systematically identify localization-based pulsing behaviors in Saccharomyces cerevisiae. The screen examined all genes in a previously developed fluorescent protein fusion library of 4,159 strains [13] in multiple media conditions. This approach revealed stochastic pulsing in ten proteins, all transcription factors. In each case, pulse dynamics were heterogeneous and unsynchronized among cells in clonal populations. Pulsing is the only dynamic localization behavior that we observed, and it tends to occur in pairs of paralogous and redundant proteins. Taken together, these results suggest that pulsatile dynamics play a pervasive role in yeast and may be similarly prevalent in other eukaryotic species. PMID:25220054

Dalal, Chiraj K; Cai, Long; Lin, Yihan; Rahbar, Kasra; Elowitz, Michael B

2014-09-22

337

Genetic Landscape of Open Chromatin in Yeast  

PubMed Central

Chromatin regulation underlies a variety of DNA metabolism processes, including transcription, recombination, repair, and replication. To perform a quantitative genetic analysis of chromatin accessibility, we obtained open chromatin profiles across 96 genetically different yeast strains by FAIRE (formaldehyde-assisted isolation of regulatory elements) assay followed by sequencing. While 5?10% of open chromatin region (OCRs) were significantly affected by variations in their underlying DNA sequences, subtelomeric areas as well as gene-rich and gene-poor regions displayed high levels of sequence-independent variation. We performed quantitative trait loci (QTL) mapping using the FAIRE signal for each OCR as a quantitative trait. While individual OCRs were associated with a handful of specific genetic markers, gene expression levels were associated with many regulatory loci. We found multi-target trans-loci responsible for a very large number of OCRs, which seemed to reflect the widespread influence of certain chromatin regulators. Such regulatory hotspots were enriched for known regulatory functions, such as recombinational DNA repair, telomere replication, and general transcription control. The OCRs associated with these multi-target trans-loci coincided with recombination hotspots, telomeres, and gene-rich regions according to the function of the associated regulators. Our findings provide a global quantitative picture of the genetic architecture of chromatin regulation. PMID:23408895

Kim, Kwoneel; Seo, Jungmin; Lee, Heun-Sik; Bogu, Gireesh K.; Kim, Dongsup; Lee, Sanghyuk; Lee, Byungwook; Choi, Jung Kyoon

2013-01-01

338

Yeast mutants overproducing iso-cytochromes c  

SciTech Connect

For over 15 years, the iso-cytochrome c system in the yeast Saccharomyces cerevisiae has been used to investigate a multitude of problems in genetics and molecular biology. More recently, attention has been focused on using mutants for examining translation and transcriptional processes and for probing regulatory regions governing gene expression. In an effort to explore regulatory mechanisms and to investigate mutational alterations that lead to increased levels of gene products, we have isolated and characterized mutants that overproduce cytochrome c. In this paper we have briefly summarized background information of some essential features of the iso-cytochrome c system and we have described the types of mutants that overproduce iso-1-cytochrome c or iso-2-cytochrome c. Genetic procedures and recombinant DNA procedures were used to demonstrate that abnormally high amounts of gene products occur in mutants as result of duplications of gene copies or of extended alteration of regulatory regions. The results summarized in this paper point out the requirements of gross mutational changes or rearrangements of chromosomal segments for augmenting gene products.

Sherman, F.; Cardillo, T.S.; Errede, B.; Friedman, L.; McKnight, G.; Stiles, J.I.

1980-01-01

339

Chlamydomonas reinhardtii as the photosynthetic yeast.  

PubMed

The green unicellular alga Chlamydomonas reinhardtii has long been used as a model system for studying photosynthesis, chloroplast biogenesis, and flagellar function and assembly because of its well-defined genetics. The value of this organism has been greatly increased recently by the development of efficient methods for nuclear and chloroplast transformation. While homologous recombination appears to occur at a low frequency in the nuclear genome, random integrations can be exploited to tag genes of interest by insertional mutagenesis. Cloning of the nuclear genes by genomic complementation is also possible. Chloroplast genetic engineering has provided new and important insights into the molecular mechanisms of chloroplast gene expression and into the function of chloroplast proteins. C. reinhardtii is probably the best organism in which to perform chloroplast DNA surgery because of the ease of chloroplast transformation in this alga. C. reinhardtii might be described as the photosynthetic yeast. However, it offers additional new promising areas of research, such as chloroplast-mitochondrial interactions, phototransduction, and the behavioral response to light. PMID:8825474

Rochaix, J D

1995-01-01

340

Multiple dextranases from the yeast Lipomyces starkeyi.  

PubMed

The soil yeast Lipomyces starkeyi (NCYC 1436) secretes dextranase activity into the growth medium. Resolution of a dextranase-active protein fraction by SDS-PAGE produced three protein bands, of 66 kDa, 68 kDa and 78 kDa, and isoelectric focusing of the same fraction resulted in seven protein bands, of pIs 3.50, 3.85, 4.20, 4.80, 4.85, 5.00 and 5.30. Dextranase activity was demonstrated for all the isoelectric forms, and for the 78 kDa species in the presence of SDS. Amino acid compositions of the 66 kDa, 68 kDa and 78 kDa protein bands were determined, and the N-termini of the 66 kDa and 78 kDa protein bands were sequenced: the first two amino acids at the N-terminus of each protein were alanine and valine, respectively; an alanine-valine pair is seen early in the N-terminal coding sequences of the dextranases and the isopullulanase produced by the phylogenetically disparate organisms contributing to glycosyl hydrolase family 49. PMID:17558545

Millson, Stefan H; Evans, Ivor Howell

2007-11-01

341

Producing aglycons of ginsenosides in bakers' yeast  

PubMed Central

Ginsenosides are the primary bioactive components of ginseng, which is a popular medicinal plant that exhibits diverse pharmacological activities. Protopanaxadiol, protopanaxatriol and oleanolic acid are three basic aglycons of ginsenosides. Producing aglycons of ginsenosides in Saccharomyces cerevisiae was realized in this work and provides an alternative route compared to traditional extraction methods. Synthetic pathways of these three aglycons were constructed in S. cerevisiae by introducing ?-amyrin synthase, oleanolic acid synthase, dammarenediol-II synthase, protopanaxadiol synthase, protopanaxatriol synthase and NADPH-cytochrome P450 reductase from different plants. In addition, a truncated 3-hydroxy-3-methylglutaryl-CoA reductase, squalene synthase and 2,3-oxidosqualene synthase genes were overexpressed to increase the precursor supply for improving aglycon production. Strain GY-1 was obtained, which produced 17.2?mg/L protopanaxadiol, 15.9?mg/L protopanaxatriol and 21.4?mg/L oleanolic acid. The yeast strains engineered in this work can serve as the basis for creating an alternative way for producing ginsenosides in place of extractions from plant sources. PMID:24424342

Dai, Zhubo; Wang, Beibei; Liu, Yi; Shi, Mingyu; Wang, Dong; Zhang, Xianan; Liu, Tao; Huang, Luqi; Zhang, Xueli

2014-01-01

342

Genetic Basis of Metabolome Variation in Yeast  

PubMed Central

Metabolism, the conversion of nutrients into usable energy and biochemical building blocks, is an essential feature of all cells. The genetic factors responsible for inter-individual metabolic variability remain poorly understood. To investigate genetic causes of metabolome variation, we measured the concentrations of 74 metabolites across 100 segregants from a Saccharomyces cerevisiae cross by liquid chromatography-tandem mass spectrometry. We found 52 quantitative trait loci for 34 metabolites. These included linkages due to overt changes in metabolic genes, e.g., linking pyrimidine intermediates to the deletion of ura3. They also included linkages not directly related to metabolic enzymes, such as those for five central carbon metabolites to ira2, a Ras/PKA pathway regulator, and for the metabolites, S-adenosyl-methionine and S-adenosyl-homocysteine to slt2, a MAP kinase involved in cell wall integrity. The variant of ira2 that elevates metabolite levels also increases glucose uptake and ethanol secretion. These results highlight specific examples of genetic variability, including in genes without prior known metabolic regulatory function, that impact yeast metabolism. PMID:24603560

Breunig, Jeffrey S.; Hackett, Sean R.; Rabinowitz, Joshua D.; Kruglyak, Leonid

2014-01-01

343

Functional distinctions between yeast TATA elements.  

PubMed Central

Although the yeast his3 promoter region contains two functional TATA elements, TR and TC, the GCN4 and GAL4 upstream activator proteins stimulate transcription only through TR. In combination with GAL4, an oligonucleotide containing the sequence TATAAA is fully sufficient for TR function, whereas almost all single-base-pair substitutions of this sequence abolish the ability of this element to activate transcription. Further analysis of these and other mutations of the TR element led to the following conclusions. First, sequences downstream of the TATAAA sequence are important for TR function. Second, a double mutant, TATTTA, can serve as a TR element even though the corresponding single mutation, TATTAA, is unable to do so. Third, three mutations have the novel property of being able to activate transcription in combination with GCN4 but not with GAL4; this finding suggests that activation by GCN4 and by GAL4 may not occur by identical mechanisms. From these observations, we address the question of whether there is a single TATA-binding factor required for the transcription of all genes. Images PMID:2685558

Harbury, P A; Struhl, K

1989-01-01

344

Isolating potentiated hsp104 variants using yeast proteinopathy models.  

PubMed

Many protein-misfolding disorders can be modeled in the budding yeast Saccharomyces cerevisiae. Proteins such as TDP-43 and FUS, implicated in amyotrophic lateral sclerosis, and ?-synuclein, implicated in Parkinson's disease, are toxic and form cytoplasmic aggregates in yeast. These features recapitulate protein pathologies observed in patients with these disorders. Thus, yeast are an ideal platform for isolating toxicity suppressors from libraries of protein variants. We are interested in applying protein disaggregases to eliminate misfolded toxic protein conformers. Specifically, we are engineering Hsp104, a hexameric AAA+ protein from yeast that is uniquely capable of solubilizing both disordered aggregates and amyloid and returning the proteins to their native conformations. While Hsp104 is highly conserved in eukaryotes and eubacteria, it has no known metazoan homologue. Hsp104 has only limited ability to eliminate disordered aggregates and amyloid fibers implicated in human disease. Thus, we aim to engineer Hsp104 variants to reverse the protein misfolding implicated in neurodegenerative disorders. We have developed methods to screen large libraries of Hsp104 variants for suppression of proteotoxicity in yeast. As yeast are prone to spontaneous nonspecific suppression of toxicity, a two-step screening process has been developed to eliminate false positives. Using these methods, we have identified a series of potentiated Hsp104 variants that potently suppress the toxicity and aggregation of TDP-43, FUS, and ?-synuclein. Here, we describe this optimized protocol, which could be adapted to screen libraries constructed using any protein backbone for suppression of toxicity of any protein that is toxic in yeast. PMID:25407485

Jackrel, Meredith E; Tariq, Amber; Yee, Keolamau; Weitzman, Rachel; Shorter, James

2014-01-01

345

Solving ethanol production problems with genetically modified yeast strains.  

PubMed

The current world demand for bioethanol is increasing as a consequence of low fossil fuel availability and a growing number of ethanol/gasoline flex-fuel cars. In addition, countries in several parts of the world have agreed to reduce carbon dioxide emissions, and the use of ethanol as a fuel (which produces fewer pollutants than petroleum products) has been considered to be a good alternative to petroleum products. The ethanol that is produced in Brazil from the first-generation process is optimized and can be accomplished at low cost. However, because of the large volume of ethanol that is produced and traded each year, any small improvement in the process could represent a savings of billions dollars. Several Brazilian research programs are investing in sugarcane improvement, but little attention has been given to the improvement of yeast strains that participate in the first-generation process at present. The Brazilian ethanol production process uses sugarcane as a carbon source for the yeast Saccharomyces cerevisiae. Yeast is then grown at a high cellular density and high temperatures in large-capacity open tanks with cells recycle. All of these culture conditions compel the yeast to cope with several types of stress. Among the main stressors are high temperatures and high ethanol concentrations inside the fermentation tanks during alcohol production. Moreover, the competition between the desired yeast strains, which are inoculated at the beginning of the process, with contaminants such as wild type yeasts and bacteria, requires acid treatment to successfully recycle the cells. This review is focused on describing the problems and stressors within the Brazilian ethanol production system. It also highlights some genetic modifications that can help to circumvent these difficulties in yeast. PMID:24516432

Abreu-Cavalheiro, A; Monteiro, G

2013-01-01

346

In vitro antimycotic activity of some plant extracts towards yeast and yeast-like strains.  

PubMed

As part of screening aimed at the selection of novel antimycotic compounds of vegetable origin, leaf extracts of Camellia sinensis L., Cupressus sempervirens L. and Pistacia lentiscus L. and the seed extract of Glycine soja Sieb. et Zucc. were tested against yeast and yeast-like species implicated in human mycoses. Of the extracts only those of C. sinensis (obtained from a commercial preparation of green tea) exhibited broad activity towards Candida glabrata, Clavispora lusitatiae, Cryptococcus laurentii, Filobasidiella neoformans, Issatchenkia orientalis, Saccharomyces cerevisiae and Prototheca wickerhamii strains. MICs ranging from 300 to 4800 microg extract/mL (corresponding to 130-2010 microg/mL total polyphenols) were observed. Concentrations of the C. sinensis extract over 25 000 microg/mL caused a rapid decrease of viable cells of Fil. neoformans and its activity was dose-dependent. Tests carried out using the pure polyphenols present in C. sinensis extract composition, showed that only epicatechin-3-O-gallate (ECG) and epigallocatechin-3-O-gallate (EGCG) possess antimycotic activity. PMID:15798996

Turchetti, B; Pinelli, P; Buzzini, P; Romani, A; Heimler, D; Franconi, F; Martini, A

2005-01-01

347

Purity Control of the Production of Baker's Yeast Employing a Fluorescent Antiserum  

PubMed Central

A simple staining procedure for the rapid detection of wild yeasts contaminating baker's yeast during the course of industrial production is described. Fluorescein-labeled, specific antiserum against Saccharomyces cerevisiae is applied to smears of baker's yeast which are then examined by ultraviolet microscopy. Optimal results are obtained with the combined phase contrast and fluorescence which makes the S. cerevisiae appear green, whereas cells of wild yeasts are visible in bright red counterstain. With this method, wild yeasts could be identified in baker's yeast at a dilution of 1:10,000. Images FIG. 1 PMID:14460617

Kunz, Ch.; Klaushofer, H.

1961-01-01

348

The Yeast Copper Response Is Regulated by DNA Damage  

PubMed Central

Copper is an essential but potentially toxic redox-active metal, so the levels and distribution of this metal are carefully regulated to ensure that it binds to the correct proteins. Previous studies of copper-dependent transcription in the yeast Saccharomyces cerevisiae have focused on the response of genes to changes in the exogenous levels of copper. We now report that yeast copper genes are regulated in response to the DNA-damaging agents methyl methanesulfonate (MMS) and hydroxyurea by a mechanism(s) that requires the copper-responsive transcription factors Mac1 and AceI, copper superoxide dismutase (Sod1) activity, and the Rad53 checkpoint kinase. Furthermore, in copper-starved yeast, the response of the Rad53 pathway to MMS is compromised due to a loss of Sod1 activity, consistent with the model that yeast imports copper to ensure Sod1 activity and Rad53 signaling. Crucially, the Mac1 transcription factor undergoes changes in its redox state in response to changing levels of copper or MMS. This study has therefore identified a novel regulatory relationship between cellular redox, copper homeostasis, and the DNA damage response in yeast. PMID:23959798

Dong, Kangzhen; Addinall, Stephen G.; Lydall, David

2013-01-01

349

The yeast Saccharomyces cerevisiae- the main character in beer brewing.  

PubMed

Historically, mankind and yeast developed a relationship that led to the discovery of fermented beverages. Numerous inventions have led to improved technologies and capabilities to optimize fermentation technology on an industrial scale. The role of brewing yeast in the beer-making process is reviewed and its importance as the main character is highlighted. On considering the various outcomes of functions in a brewery, it has been found that these functions are focused on supporting the supply of yeast requirements for fermentation and ultimately to maintain the integrity of the product. The functions/processes include: nutrient supply to the yeast (raw material supply for brewhouse wort production); utilities (supply of water, heat and cooling); quality assurance practices (hygiene practices, microbiological integrity measures and other specifications); plant automation (vessels, pipes, pumps, valves, sensors, stirrers and centrifuges); filtration and packaging (product preservation until consumption); distribution (consumer supply); and marketing (consumer awareness). Considering this value chain of beer production and the 'bottle neck' during production, the spotlight falls on fermentation, the age-old process where yeast transforms wort into beer. PMID:18795959

Lodolo, Elizabeth J; Kock, Johan L F; Axcell, Barry C; Brooks, Martin

2008-11-01

350

Divergence of iron metabolism in wild Malaysian yeast.  

PubMed

Comparative genomic studies have reported widespread variation in levels of gene expression within and between species. Using these data to infer organism-level trait divergence has proven to be a key challenge in the field. We have used a wild Malaysian population of S. cerevisiae as a test bed in the search to predict and validate trait differences based on observations of regulatory variation. Malaysian yeast, when cultured in standard medium, activated regulatory programs that protect cells from the toxic effects of high iron. Malaysian yeast also showed a hyperactive regulatory response during culture in the presence of excess iron and had a unique growth defect in conditions of high iron. Molecular validation experiments pinpointed the iron metabolism factors AFT1, CCC1, and YAP5 as contributors to these molecular and cellular phenotypes; in genome-scale sequence analyses, a suite of iron toxicity response genes showed evidence for rapid protein evolution in Malaysian yeast. Our findings support a model in which iron metabolism has diverged in Malaysian yeast as a consequence of a change in selective pressure, with Malaysian alleles shifting the dynamic range of iron response to low-iron concentrations and weakening resistance to extreme iron toxicity. By dissecting the iron scarcity specialist behavior of Malaysian yeast, our work highlights the power of expression divergence as a signpost for biologically and evolutionarily relevant variation at the organismal level. Interpreting the phenotypic relevance of gene expression variation is one of the primary challenges of modern genomics. PMID:24142925

Lee, Hana N; Mostovoy, Yulia; Hsu, Tiffany Y; Chang, Amanda H; Brem, Rachel B

2013-12-01

351

Immobilized yeast bioreactor systems for continuous beer fermentation  

PubMed

Two different types of immobilized yeast bioreactors were examined for continuous fermentation of high-gravity worts. One of these is a fluidized bed reactor (FBR) that employs porous glass beads for yeast immobilization. The second system is a loop reactor containing a porous silicon carbide cartridge (SCCR) for immobilizing the yeast cells. Although there was some residual fermentable sugar in the SCCR system product, nearly complete attenuation of the wort sugars was achieved in either of the systems when operated as a two-stage process. Fermentation could be completed in these systems in only half the time required for a conventional batch process. Both the systems showed similar kinetics of extract consumption, and therefore similar volumetric productivity. As compared to the batch fermentation, total fusel alcohols were lower; total esters, while variable, were generally higher. The yeast biomass production was similar to that in a conventional fermentation process. As would be expected in an accelerated fermentation system, the levels of vicinal diketones (VDKs) were higher. To remove the VDKs, the young beer was heat-treated to convert the VDK precursors and processed through a packed bed immobilized yeast bioreactor for VDK assimilation. The finished product from the FBR system was found to be quite acceptable from a flavor perspective, albeit different from the product from a conventional batch process. Significantly shortened fermentation times demonstrate the feasibility of this technology for beer production. PMID:9933520

Tata; Bower; Bromberg; Duncombe; Fehring; Lau; Ryder; Stassi

1999-01-01

352

Evolutionary Role of Interspecies Hybridization and Genetic Exchanges in Yeasts  

PubMed Central

Summary: Forced interspecific hybridization has been used in yeasts for many years to study speciation or to construct artificial strains with novel fermentative and metabolic properties. Recent genome analyses indicate that natural hybrids are also generated spontaneously between yeasts belonging to distinct species, creating lineages with novel phenotypes, varied genetic stability, or altered virulence in the case of pathogens. Large segmental introgressions from evolutionarily distant species are also visible in some yeast genomes, suggesting that interspecific genetic exchanges occur during evolution. The origin of this phenomenon remains unclear, but it is likely based on weak prezygotic barriers, limited Dobzhansky-Muller (DM) incompatibilities, and rapid clonal expansions. Newly formed interspecies hybrids suffer rapid changes in the genetic contribution of each parent, including chromosome loss or aneuploidy, translocations, and loss of heterozygosity, that, except in a few recently studied cases, remain to be characterized more precisely at the genomic level by use of modern technologies. We review here known cases of natural or artificially formed interspecies hybrids between yeasts and discuss their potential importance in terms of genome evolution. Problems of meiotic fertility, ploidy constraint, gene and gene product compatibility, and nucleomitochondrial interactions are discussed and placed in the context of other known mechanisms of yeast genome evolution as a model for eukaryotes. PMID:23204364

Dujon, Bernard

2012-01-01

353

Relative incidence of ascomycetous yeasts in arctic coastal environments.  

PubMed

Previous studies of fungi in polar environments have revealed a prevalence of basidiomycetous yeasts in soil and in subglacial environments of polythermal glaciers. Ascomycetous yeasts have rarely been reported from extremely cold natural environments, even though they are known contaminants of frozen foods. Using media with low water activity, we have isolated various yeast species from the subglacial ice of four glaciers from the coastal Arctic environment of Kongsfjorden, Spitzbergen, including Debaryomyces hansenii and Pichia guillermondii, with counts reaching 10(4) CFU L(-1). Together with the basidiomycetes Cryptococcus liquefaciens and Rhodotorula mucilaginosa, these yeasts represent the stable core of the subglacial yeast communities. Other glacial ascomycetous species isolated included Candida parapsilosis and a putative new species that resembles Candida pseudorugosa. The archiascomycete Protomyces inouyei has seldom been detected anywhere in the world but was here recovered from ice in a glacier cave. The glacier meltwater contained only D. hansenii, whereas the seawater contained D. hansenii, Debaryomyces maramus, Pichia guilliermondii, what appears to represent a novel species resembling Candida galli and Metschnikowia bicuspidata. Only P. guilliermondii was isolated from sea ice, while snow/ice in the fjord tidal zone included C. parapsilosis, D. hansenii, P. guilliermondii and Metschnikowia zobellii. All of these isolated strains were characterized as psychrotolerant and xero/halotolerant, with the exception of P. inouyei. PMID:21221569

Butinar, Lorena; Strmole, Tadeja; Gunde-Cimerman, Nina

2011-05-01

354

Optimizing bioethanol production by regulating yeast growth energy.  

PubMed

The goal of this work is to optimize production of bio-ethanol by fermentation through regulating yeast growth energy (YGE), and provide the mechanism of ethanol production from food-waste leachate (FWL) using yeast (S. cerevisiae) as inoculums to be predictable and controllable. The wide range of reduced sugar concentration (RSC) which is commonly administered from low (35 g per liter) to very high (100 g per liter) is responsible for costs increasing besides risks of FWL contamination and death of yeast cells. A mathematical model is presented to describe yeast growth energy (YGE) due to RSC doses along with predicting the amounts of ethanol yield by each dose to identify the optimum one. Simulations of the presented model showed that YGE, energy intake (EI), and their produced ethanol energy (PEE) are always balanced during fermentation process according to the law of conservation of energy. For a better fermentation rate in a continuous process and a large-scale production; YGE should be less than half of EI and more than its quarter (i.e. [Formula: see text]) which keeps the residual energy less than YGE to avoid risks of osmotic stresses or aging of cells allowing the survival of all yeast cells as long as possible to maximize ethanol production and decrease productivity costs. PMID:24294340

Moawad, Emad Y

2012-12-01

355

Patterns of human oral yeast species distribution on Hainan Island in China.  

PubMed

Infections by yeast strains of the genus Candida are among the most prevalent fungal infections of humans. These yeasts are common residents of the oral mucosa and other body surfaces. Since most yeast infections are due to endogenous strains and that species of Candida differ in virulence properties and in intrinsic susceptibilities to antifungal drugs, understanding the human commensal yeast flora can help designing effective treatment and prevention strategies against yeast infections. Here, we report the patterns of yeast species distributions in the oral cavities of 1,799 people from Hainan Island in southern China. Based on sequence information at the fungal barcode locus ITS regions, 368 of the 415 obtained oral yeast strains were identified as belonging to 26 yeast species, while the remaining 47 strains all showed significant sequence divergence to the currently described species. The four most common yeast species were C. albicans (42 %), C. tropicalis (20 %), C. glabrata (5.5 %), and C. parapsilosis (4.1 %) and 10 of the 26 yeast species were represented by only one strain each. Our analyses identified that the gender of hosts and ethnical background showed no contribution to oral yeast species distributions. However, the health status, place of birth, current residency, and the age of hosts all showed significant contributions to the distributions of the four dominant yeast species. We compared our results with those reported previously and discussed the potential mechanisms for the observed differences in oral yeast species distributions. PMID:24085613

Wang, Huamin; Xu, Jianping; Guo, Hong; Wu, Jinyan; Yi, Guohui; Pei, Hua; Niu, Lina; Li, Yi

2013-12-01

356

Expression of the Novel Wheat Gene TM20 Confers Enhanced Cadmium Tolerance to Bakers' Yeast*S?  

PubMed Central

Cadmium causes the generation of reactive oxygen species, which in turn causes cell damage. We isolated a novel gene from a wheat root cDNA library, which conferred Cd(II)-specific tolerance when expressed in yeast (Saccharomyces cerevisiae). The gene, which we called TaTM20, for Triticum aestivum transmembrane 20, encodes a putative hydrophobic polypeptide of 889 amino acids, containing 20 transmembrane domains arranged as a 5-fold internal repeating unit of 4 transmembrane domains each. Expression of TaTM20 in yeast cells stimulated Cd(II) efflux resulting in a decrease in the content of yeast intracellular cadmium. TaTM20-induced Cd(II) tolerance was maintained in yeast even under conditions of reduced GSH. These results demonstrate that TaTM20 enhances Cd(II) tolerance in yeast through the stimulation of Cd(II) efflux from the cell, partially independent of GSH. Treatment of wheat seedlings with Cd(II) induced their expression of TaTM20, decreasing subsequent root Cd(II) accumulation and suggesting a possible role for TaTM20 in Cd(II) tolerance in wheat. PMID:18411273

Kim, Yu-Young; Kim, Do-Young; Shim, Donghwan; Song, Won-Yong; Lee, Joohyun; Schroeder, Julian I.; Kim, Sanguk; Moran, Nava; Lee, Youngsook

2008-01-01

357

Synthetic biology for engineering acetyl coenzyme a metabolism in yeast.  

PubMed

The yeast Saccharomyces cerevisiae is a widely used cell factory for the production of fuels, chemicals, and pharmaceuticals. The use of this cell factory for cost-efficient production of novel fuels and chemicals requires high yields and low by-product production. Many industrially interesting chemicals are biosynthesized from acetyl coenzyme A (acetyl-CoA), which serves as a central precursor metabolite in yeast. To ensure high yields in production of these chemicals, it is necessary to engineer the central carbon metabolism so that ethanol production is minimized (or eliminated) and acetyl-CoA can be formed from glucose in high yield. Here the perspective of generating yeast platform strains that have such properties is discussed in the context of a major breakthrough with expression of a functional pyruvate dehydrogenase complex in the cytosol. PMID:25370498

Nielsen, Jens

2014-01-01

358

Synthetic Biology for Engineering Acetyl Coenzyme A Metabolism in Yeast  

PubMed Central

ABSTRACT The yeast Saccharomyces cerevisiae is a widely used cell factory for the production of fuels, chemicals, and pharmaceuticals. The use of this cell factory for cost-efficient production of novel fuels and chemicals requires high yields and low by-product production. Many industrially interesting chemicals are biosynthesized from acetyl coenzyme A (acetyl-CoA), which serves as a central precursor metabolite in yeast. To ensure high yields in production of these chemicals, it is necessary to engineer the central carbon metabolism so that ethanol production is minimized (or eliminated) and acetyl-CoA can be formed from glucose in high yield. Here the perspective of generating yeast platform strains that have such properties is discussed in the context of a major breakthrough with expression of a functional pyruvate dehydrogenase complex in the cytosol. PMID:25370498

2014-01-01

359

Yeast PPR proteins, watchdogs of mitochondrial gene expression  

PubMed Central

PPR proteins are a family of ubiquitous RNA-binding factors, found in all the Eukaryotic lineages, and are particularly numerous in higher plants. According to recent bioinformatic analyses, yeast genomes encode from 10 (in S. pombe) to 15 (in S. cerevisiae) PPR proteins. All of these proteins are mitochondrial and very often interact with the mitochondrial membrane. Apart from the general factors, RNA polymerase and RNase P, most yeast PPR proteins are involved in the stability and/or translation of mitochondrially encoded RNAs. At present, some information concerning the target RNA(s) of most of these proteins is available, the next challenge will be to refine our understanding of the function of the proteins and to resolve the yeast PPR-RNA-binding code, which might differ significantly from the plant PPR code. PMID:24184848

Herbert, Christopher J; Golik, Pawel; Bonnefoy, Nathalie

2013-01-01

360

Breeding of a new wastewater treatment yeast by genetic engineering.  

PubMed

We previously developed a host vector system for the wastewater treatment yeast Hansenula fabianii J640. The promoter and terminator regions of the gene encoding glucoamylase from H. fabianii J640 were used for a new expression vector, pHFGE-1. The performance of pHFGE-1 was compared with that of the widely used pG-1 transformant vector. H. fabianii J640 (HF-TAMY) cells were transformed with pHFGE-1, and Saccharomyces cerevisiae YPH-499 (SC-TAMY) cells were transformed with pG-1, both of which carried the Taka-amylase. Expression of Taka-amylase by HF-TAMY showed higher than that by SC-TAMY. By using this new system, we bred the new wastewater treatment yeast that shows ?-amylase activity. This yeast appears to grow well under experimental wastewater conditions, and is effective in treating model wastewater containing soluble and insoluble starch. PMID:21906339

Kato, Miyoshi; Iefuji, Haruyuki

2011-01-01

361

Breeding of a new wastewater treatment yeast by genetic engineering  

PubMed Central

We previously developed a host vector system for the wastewater treatment yeast Hansenula fabianii J640. The promoter and terminator regions of the gene encoding glucoamylase from H. fabianii J640 were used for a new expression vector, pHFGE-1. The performance of pHFGE-1 was compared with that of the widely used pG-1 transformant vector. H. fabianii J640 (HF-TAMY) cells were transformed with pHFGE-1, and Saccharomyces cerevisiae YPH-499 (SC-TAMY) cells were transformed with pG-1, both of which carried the Taka-amylase. Expression of Taka-amylase by HF-TAMY showed higher than that by SC-TAMY. By using this new system, we bred the new wastewater treatment yeast that shows ?-amylase activity. This yeast appears to grow well under experimental wastewater conditions, and is effective in treating model wastewater containing soluble and insoluble starch. PMID:21906339

2011-01-01

362

Recombinant brewer's yeast strains suitable for accelerated brewing.  

PubMed

Four brewer's yeast strains carrying the alpha-ald gene of Klebsiella terrigena (ex. Aerobacter aerogenes) or of Enterobacter aerogenes on autonomously replicating plasmids were constructed. The alpha-ald genes were linked either to the ADC1 promoter or to the PGK1 promoter of yeast Saccharomyces cerevisiae. In pilot scale brewing (50 l) with three of these recombinant yeasts the formation of diacetyl in beer was so low during fermentation that lagering was not required. All other brewing properties of the strains were unaffected and the quality of finished beers was as good as that of finished beer prepared with the control strain. The total process time of beer production could therefore be reduced to 2 weeks, in contrast to about 5 weeks required in the conventional process. PMID:1366907

Suihko, M L; Blomqvist, K; Penttilä, M; Gisler, R; Knowles, J

1990-06-01

363

Chromatin architectures at fission yeast transcriptional promoters and replication origins  

PubMed Central

We have used micrococcal nuclease (MNase) digestion followed by deep sequencing in order to obtain a higher resolution map than previously available of nucleosome positions in the fission yeast, Schizosaccharomyces pombe. Our data confirm an unusually short average nucleosome repeat length, ?152?bp, in fission yeast and that transcriptional start sites (TSSs) are associated with nucleosome-depleted regions (NDRs), ordered nucleosome arrays downstream and less regularly spaced upstream nucleosomes. In addition, we found enrichments for associated function in four of eight groups of genes clustered according to chromatin configurations near TSSs. At replication origins, our data revealed asymmetric localization of pre-replication complex (pre-RC) proteins within large NDRs—a feature that is conserved in fission and budding yeast and is therefore likely to be conserved in other eukaryotic organisms. PMID:22573177

Givens, Robert M.; Lai, William K. M.; Rizzo, Jason M.; Bard, Jonathan E.; Mieczkowski, Piotr A.; Leatherwood, Janet; Huberman, Joel A.; Buck, Michael J.

2012-01-01

364

Saccharomyces cerevisiae STR3 and yeast cystathionine ?-lyase enzymes  

PubMed Central

Selected Saccharomyces cerevisiae strains are used for wine fermentation. Based on several criteria, winemakers often use a specific yeast to improve the flavor, mouth feel, decrease the alcohol content and desired phenolic content, just to name a few properties. Scientists at the AWRI previously illustrated the potential for increased flavor release from grape must via overexpression of the Escherichia coli Tryptophanase enzyme in wine yeast. To pursue a self-cloning approach for improving the aroma production, we recently characterized the S. cerevisiae cystathionine ?-lyase STR3, and investigated its flavor releasing capabilities. Here, we continue with a phylogenetic investigation of STR3 homologs from non-Saccharomyces yeasts to map the potential for using natural variation to engineer new strains. PMID:22572787

Holt, Sylvester; Cordente, Antonio G.; Curtin, Chris

2012-01-01

365

Saccharomyces cerevisiae: a sexy yeast with a prion problem.  

PubMed

Yeast prions are infectious proteins that spread exclusively by mating. The frequency of prions in the wild therefore largely reflects the rate of spread by mating counterbalanced by prion growth slowing effects in the host. We recently showed that the frequency of outcross mating is about 1% of mitotic doublings with 23-46% of total matings being outcrosses. These findings imply that even the mildest forms of the [PSI+], [URE3] and [PIN+] prions impart > 1% growth/survival detriment on their hosts. Our estimate of outcrossing suggests that Saccharomyces cerevisiae is far more sexual than previously thought and would therefore be more responsive to the adaptive effects of natural selection compared with a strictly asexual yeast. Further, given its large effective population size, a growth/survival detriment of > 1% for yeast prions should strongly select against prion-infected strains in wild populations of Saccharomyces cerevisiae. PMID:23764836

Kelly, Amy C; Wickner, Reed B

2013-01-01

366

Delimination of brewing yeast strains using different molecular techniques.  

PubMed

In general, the genetic characteristics, the phenotype and the microbial purity of the production brewing yeast strains are among the most important factors in maintaining a consistently good quality of products. Analysis of restriction fragment length polymorphism (RFLP) patterns of 18S rRNA-coding DNA was investigated to group ale and lager strains. All production brewing yeast strains showed the same RFLP pattern as the type strain and synonym type strains of S. cerevisiae, and were quite different from the type and synonym type strains of S. pastorianus. Based on these data, all production brewing yeast strains investigated in this study appeared to belong to S. cerevisiae. Electrophoretic karyotyping and random amplified polymorphic DNA (RAPD) analysis appeared to be suitable methods for distinguishing not only the type and synonym type strain of S. cerevisiae and S. pastorianus, but also the ale and the lager strains. PMID:11139020

Tornai-Lehoczki, J; Dlauchy, D

2000-12-01

367

The Effects of an Increased Amount of Mitochondrial DNA on the Yeast Metabolic Cycle  

E-print Network

When prototrophic yeast cells undergo continuous growth in nutrient-limited conditions, they experience robust metabolic oscillations. Additionally, the processes of metabolism in yeast cells have been shown to be coordinated with cell division...

Gajjar, Shefali Rajendra

2008-05-21

368

Confinement to Organelle-Associated Inclusion Structures Mediates Asymmetric Inheritance of Aggregated Protein in Budding Yeast  

E-print Network

The division of the S. cerevisiae budding yeast, which produces one mother cell and one daughter cell, is asymmetric with respect to aging. Remarkably, the asymmetry of yeast aging coincides with asymmetric inheritance of ...

Spokoini, Rachel

369

High-resolution x-ray diffraction microscopy of specifically labeled yeast cells  

E-print Network

High-resolution x-ray diffraction microscopy of specifically labeled yeast cells Johanna Nelsona,1 of the yeast Saccharomyces cerevisiae. Cells were plunge-frozen in liquid ethane and freeze-dried, after which

Mohseni, Hooman

370

Budding yeast cell cycle analysis and morphological characterization by automated image analysis  

E-print Network

Budding yeast Saccharomyces cerevisiae is a standard model system for analyzing cellular response as it is related to the cell cycle. The analysis of yeast cell cycle is typically done visually or by using flow cytometry. ...

Perley, Elizabeth (Elizabeth Bacher)

2011-01-01

371

Comprehensive Analysis of Combinatorial Regulation using the Transcriptional Regulatory Network of Yeast  

E-print Network

of Yeast S. Balaji1 , M. Madan Babu1 , Lakshminarayan M. Iyer1 Nicholas M. Luscombe2 and L. Aravind1 1 approach this problem by using the largest assembled transcriptional regulatory network for yeast

Zhang, Nancy R.

372

Prions are a common mechanism for phenotypic inheritance in wild yeasts  

E-print Network

The self-templating conformations of yeast prion proteins act as epigenetic elements of inheritance. Yeast prions might provide a mechanism for generating heritable phenotypic diversity that promotes survival in fluctuating ...

Halfmann, Randal

373

Stimulation of RTH1 Nuclease of the Yeast Saccharomyces cereVisiae by Replication Protein A  

E-print Network

Stimulation of RTH1 Nuclease of the Yeast Saccharomyces cereVisiae by Replication Protein A Esther-stranded circular DNA as a template. The RAD2 gene product of the yeast Saccharomyces cereVisiae has been shown

Ronquist, Fredrik

374

Associations of Yeasts with Spotted-Wing Drosophila (Drosophila suzukii; Diptera: Drosophilidae) in Cherries and Raspberries  

PubMed Central

A rich history of investigation documents various Drosophila-yeast mutualisms, suggesting that Drosophila suzukii similarly has an association with a specific yeast species or community. To discover candidate yeast species, yeasts were isolated from larval frass, adult midguts, and fruit hosts of D. suzukii. Terminal restriction fragment length polymorphism (TRFLP) technology and decimal dilution plating were used to identify and determine the relative abundance of yeast species present in fruit juice samples that were either infested with D. suzukii or not infested. Yeasts were less abundant in uninfested than infested samples. A total of 126 independent yeast isolates were cultivated from frass, midguts, and fruit hosts of D. suzukii, representing 28 species of yeasts, with Hanseniaspora uvarum predominating. This suggests an association between D. suzukii and H. uvarum that could be utilized for pest management of the highly pestiferous D. suzukii. PMID:22582060

Hernandez, Alejandro; Zalom, Frank G.

2012-01-01

375

RNA Methylation by the MIS Complex Regulates a Cell Fate Decision in Yeast  

E-print Network

For the yeast Saccharomyces cerevisiae, nutrient limitation is a key developmental signal causing diploid cells to switch from yeast-form budding to either foraging pseudohyphal (PH) growth or meiosis and sporulation. ...

Agarwala, Sundeep

376

Inventions on baker's yeast storage and activation at the bakery plant.  

PubMed

Baker's yeast is the gas-forming ingredient in bakery products. Methods have been invented to properly handle baker's yeast and optimize its activity at the bakery plant. Over the years, incentives for inventions on yeast storage and activation have greatly changed depending on trends in the baking industry. For example, retailer's devices for cutting bulk pressed yeast and techniques for activating dry yeast have now lost their importance. Review of patents for invention indicates that activation of baker's yeast activity has been a very important issue for bakers, for example, with baking ingredients called yeast foods. In the recent years and especially for highly automated bakeries, interest has moved to equipments and processes for optimized storage of liquid cream yeast to thoroughly control dough fermentation and bread quality. PMID:20653548

Gélinas, Pierre

2010-01-01

377

Associations of yeasts with spotted-wing Drosophila (Drosophila suzukii; Diptera: Drosophilidae) in cherries and raspberries.  

PubMed

A rich history of investigation documents various Drosophila-yeast mutualisms, suggesting that Drosophila suzukii similarly has an association with a specific yeast species or community. To discover candidate yeast species, yeasts were isolated from larval frass, adult midguts, and fruit hosts of D. suzukii. Terminal restriction fragment length polymorphism (TRFLP) technology and decimal dilution plating were used to identify and determine the relative abundance of yeast species present in fruit juice samples that were either infested with D. suzukii or not infested. Yeasts were less abundant in uninfested than infested samples. A total of 126 independent yeast isolates were cultivated from frass, midguts, and fruit hosts of D. suzukii, representing 28 species of yeasts, with Hanseniaspora uvarum predominating. This suggests an association between D. suzukii and H. uvarum that could be utilized for pest management of the highly pestiferous D. suzukii. PMID:22582060

Hamby, Kelly A; Hernández, Alejandro; Boundy-Mills, Kyria; Zalom, Frank G

2012-07-01

378

Heritable yeast prions have a highly organized three-dimensional architecture with interfiber structures  

E-print Network

Yeast prions constitute a “protein-only” mechanism of inheritance that is widely deployed by wild yeast to create diverse phenotypes. One of the best-characterized prions, [PSI+], is governed by a conformational change in ...

Lindquist, Susan

379

Genotyping 1000 yeast strains by next-generation sequencing  

PubMed Central

Background The throughput of next-generation sequencing machines has increased dramatically over the last few years; yet the cost and time for library preparation have not changed proportionally, thus representing the main bottleneck for sequencing large numbers of samples. Here we present an economical, high-throughput library preparation method for the Illumina platform, comprising a 96-well based method for DNA isolation for yeast cells, a low-cost DNA shearing alternative, and adapter ligation using heat inactivation of enzymes instead of bead cleanups. Results Up to 384 whole-genome libraries can be prepared from yeast cells in one week using this method, for less than 15 euros per sample. We demonstrate the robustness of this protocol by sequencing over 1000 yeast genomes at ~30x coverage. The sequence information from 768 yeast segregants derived from two divergent S. cerevisiae strains was used to generate a meiotic recombination map at unprecedented resolution. Comparisons to other datasets indicate a high conservation of recombination at a chromosome-wide scale, but differences at the local scale. Additionally, we detected a high degree of aneuploidy (3.6%) by examining the sequencing coverage in these segregants. Differences in allele frequency allowed us to attribute instances of aneuploidy to gains of chromosomes during meiosis or mitosis, both of which showed a strong tendency to missegregate specific chromosomes. Conclusions Here we present a high throughput workflow to sequence genomes of large number of yeast strains at a low price. We have used this workflow to obtain recombination and aneuploidy data from hundreds of segregants, which can serve as a foundation for future studies of linkage, recombination, and chromosomal aberrations in yeast and higher eukaryotes. PMID:23394869

2013-01-01

380

In vitro attachment of phylloplane yeasts to Botrytis cinerea, Rhizoctonia solani, and Sclerotinia homoeocarpa.  

PubMed

The ability of yeasts to attach to hyphae or conidia of phytopathogenic fungi has been speculated to contribute to biocontrol activity on plant surfaces. Attachment of phylloplane yeasts to Botrytis cinerea, Rhizoctonia solani, and Sclerotinia homoeocarpa was determined using in vitro attachment assays. Yeasts were incubated for 2 d on potato dextrose agar (PDA) prior to experimentation. A total of 292 yeasts cultured on PDA were screened for their ability to attach to conidia of B. cinerea; 260 isolates (89.1%) attached to conidia forming large aggregates of cells, and 22 isolates (7.5%) weakly attached to conidia with 1 or 2 yeast cells attached to a few conidia. Ten yeasts (3.4%), including 8 isolates of Cryptococcus laurentii, 1 isolate of Cryptococcus flavescens, and an unidentified species of Cryptococcus, failed to attach to conidia. All non-attaching yeasts produced copious extracellular polysaccharide (EPS) on PDA. Seventeen yeast isolates did not attach to hyphal fragments of B. cinerea, R. solani, and S. homoeocarpa after a 1 h incubation, but attachment was observed after 24 h. Culture medium, but not culture age, significantly affected the attachment of yeast cells to conidia of B. cinerea. The 10 yeast isolates that did not attach to conidia when grown on agar did attach to conidia (20%-57% of conidia with attached yeast cells) when cultured in liquid medium. Attachment of the biocontrol yeast Rhodotorula glutinis PM4 to conidia of B. cinerea was significantly greater at 1 x 10(7) yeast cells x mL(-1) than at lower concentrations of yeast cells. The ability of yeast cells to attach to fungal conidia or hyphae appears to be a common phenotype among phylloplane yeasts. PMID:15714235

Allen, Tom W; Burpee, Leon L; Buck, James W

2004-12-01

381

Extracellular chromate-reducing activity of the yeast cultures  

Microsoft Academic Search

This paper reports on the experimental data supporting an essential role of extra-cellular reduction in chromate detoxification\\u000a by baker’s and non-conventional yeasts. A decrease of chromate content in the yeast culture coincides with an increase of\\u000a Cr(III) content in extra-cellular liquid. At these conditions, cell-bound chromium level was insignificant and a dominant\\u000a part of extra-cellular Cr(III) species was detected in

Helena P. Ksheminska; Taras M. Honchar; Galyna Z. Gayda; Mykhailo V. Gonchar

2006-01-01

382

p -coumaroylamino acids from yeast-elicited Ephedra distachya cultures  

Microsoft Academic Search

Threep-coumaroylamino acids (p-CAAs) were isolated from the yeast-elicitedEphedra distachya cultures by consecutive purification using XAD-2, silicagel and RP-HPLC. Retention times on HPLC as well as their UV, IR,\\u000a NMR and MS spectral data indicated that the yeast-inducedp-CAAs werep-coumaroyl-D-valine,p-coumaroyl-D-serine andp-coumaroyl-D-threonine, respectively. The structures ofp-CAAs were confirmed by the comparison of their physico-chemical properties with those of synthetic ones. They were isolated

Kyung-Sik Song; Ushio Sankawa; Yutaka Ebizuka

1994-01-01

383

Crystal structure of the protein kinase domain of yeast AMP-activated protein kinase Snf1  

E-print Network

Crystal structure of the protein kinase domain of yeast AMP-activated protein kinase Snf1 Michael J of the protein kinase domain (KD) of the catalytic subunit of yeast AMPK (commonly known as SNF1). The Snf1-KD by phosphatases. AMPK is found in all eukaryotes. Yeast AMPK is more commonly known as SNF1 [1,6,7]. SNF1 has

Tong, Liang

384

Identification of Protein Complexes by Comparative Analysis of Yeast and Bacterial Protein Interaction Data  

E-print Network

conservation to find complexes that are common to yeast S. Cerevisiae and bacteria H. pylori. Our analysis this approach on the data currently available for yeast and bacteria and detected 11 significantly conserved for a variety of uncharacterized proteins. By identifying a conserved complex whose yeast proteins function

Shamir, Ron

385

Site-specific genomic (SSG) and random domain-localized (RDL) mutagenesis in yeast  

Microsoft Academic Search

BACKGROUND: A valuable weapon in the arsenal available to yeast geneticists is the ability to introduce specific mutations into yeast genome. In particular, methods have been developed to introduce deletions into the yeast genome using PCR fragments. These methods are highly efficient because they do not require cloning in plasmids. RESULTS: We have modified the existing method for introducing deletions

Misa Gray; Martin Kupiec; Saul M Honigberg

2004-01-01

386

Cloning of Aspergillus niger genes in yeast. Expression of the gene coding Aspergillus ? -glucosidase  

Microsoft Academic Search

The possibility of cloning filamentous fungal genes by expression in the yeast Saccharomyces cerevisiae has been studied. A genome bank of Aspergillus niger was made in E. coli using a yeast cosmid shuttle vector and over 10,000 different cosmid clones were individually isolated. Yeast transformants carrying Aspergillus DNA were screened for the expression of the genes for fungal secreted glycoproteins,

Meria E. Penttilä; K. M. Helena Nevalainen; Alain Raynal; Jonathan K. C. Knowles

1984-01-01

387

Structure of a Yeast RNase III dsRBD Complex with a Noncanonical RNA Substrate Provides  

E-print Network

Structure Article Structure of a Yeast RNase III dsRBD Complex with a Noncanonical RNA Substrate et al., 1999) in budding yeast. Rnt1p is also important for mRNA quality control, cleaving intronic related yeast species such as S. castellii and Kluyveromyces polysporus. Introduction of S. castellii

Chanfreau, Guillaume

388

Phenotypic Mutation Rates and the Abundance of Abnormal Proteins in Yeast  

E-print Network

Phenotypic Mutation Rates and the Abundance of Abnormal Proteins in Yeast Martin Willensdorfer1 yeast protein. For phenotypic mutation rates much above 5 3 10Ã?4 , the error-free synthesis of large rates and the abundance of abnormal proteins in yeast. PLoS Comput Biol 3(11): e203. doi:10. 1371

Nowak, Martin A.

389

YEAST VOL. 14: 409417 (1998) Identification and Analysis of Homologues of  

E-print Network

YEAST VOL. 14: 409­417 (1998) Identification and Analysis of Homologues of Saccharomyces cerevisiae­function relationships, we have identified and studied Spt3 homologues from three other yeasts: Kluyveromyces lactis conserved among distantly related yeasts. The new sequences have been entered in GenBank: AF005930 (K

Winston, Fred

390

A model of yeast cell-cycle regulation based on multisite phosphorylation  

E-print Network

A model of yeast cell-cycle regulation based on multisite phosphorylation Debashis Barik1 fluctuations on cell-cycle progression in budding yeast cells, we have constructed a new model to the level of molecular noise expected in yeast-sized cells (B50 fL volume). The model gives a quantitatively

Paul, Mark

391

Yeast Functional Genomic Screens Lead to Identification of a Role for a Bacterial  

E-print Network

Yeast Functional Genomic Screens Lead to Identification of a Role for a Bacterial Effector developed a systems biological approach using the yeast Saccharomyces cerevisiae that can expedite the viable yeast haploid deletion strain collection for mutants hypersensitive to expression of the Shigella

Starnbach, Michael

392

Classification of Yeast Cells from Image Features to Evaluate Pathogen Conditions  

E-print Network

Classification of Yeast Cells from Image Features to Evaluate Pathogen Conditions Peter van der), Leiden University, Niels Bohrweg 1, 2333 CA Leiden, The Netherlands b Yeast Research, CBS Fungal in the images. We have performed an image-features-based classification for the pathogenic yeast Cryptococcus

Putten, Peter van der

393

Growth landscape formed by perception and import of glucose in yeast  

E-print Network

ARTICLES Growth landscape formed by perception and import of glucose in yeast Hyun Youk1 key events at the cell membrane--extracellular glucose sensing and uptake--initiate the budding yeast and import are separate and pivotal modules of yeast growth, the interaction of which can be precisely tuned

van Oudenaarden, Alexander

394

The Yeast Resource Center Public Data Repository Michael Riffle, Lars Malmstrom and Trisha N. Davis*  

E-print Network

The Yeast Resource Center Public Data Repository Michael Riffle, Lars Malmstro¨m and Trisha N, 2004; Revised and Accepted October 6, 2004 ABSTRACT The Yeast Resource Center Public Data Repository- tions typically studying Saccharomyces cerevisiae (baker's yeast). The experimental data include large

Davis, Trisha N.

395

A Screen for Recessive Speciation Genes Expressed in the Gametes of F1 Hybrid Yeast  

E-print Network

A Screen for Recessive Speciation Genes Expressed in the Gametes of F1 Hybrid Yeast Duncan Greig not play a major role in yeast speciation. Citation: Greig D (2007) A screen for recessive speciation genes expressed in the gametes of F1 hybrid yeast. PLoS Genet 3(2): e21. doi:10.1371/journal.pgen.0030021

Nachman, Michael

396

Comparison of the Yeast Proteome to Other Fungal Genomes to Find Core Fungal Genes  

E-print Network

Comparison of the Yeast Proteome to Other Fungal Genomes to Find Core Fungal Genes Tom Hsiang,1 indicate what makes fungi different from other organisms. By comparing 6355 predicted or known yeast, a list of 3340 yeast genes was obtained with homologs present in at least 12 of 14 fungal genomes

Hsiang, Tom

397

YEAST VOL. 14: 701710 (1998) Pombe: A Gene-finding and Exon-intron Structure  

E-print Network

YEAST VOL. 14: 701­710 (1998) Pombe: A Gene-finding and Exon-intron Structure Prediction System for Fission Yeast TING CHEN1 * AND MICHAEL Q. ZHANG2 1 Department of Computer Science, The State University://clio.cshl.org/genefinder. 1998 John Wiley & Sons, Ltd. Yeast 14: 701­710, 1998. KEY WORDS -- gene recognition; linear

398

The Yeast Transcription Factor Mac1 Binds to DNA in a Modular Fashion*  

E-print Network

The Yeast Transcription Factor Mac1 Binds to DNA in a Modular Fashion* (Received for publication is a metalloregulatory protein that regulates ex- pression of the high affinity copper transport system in the yeast of the DNA binding domain of Mac1 (called here Mac1t) with the two CuRE sites found in the yeast CTR1

Tullius, Thomas D.

399

Structure theorems and the dynamics of nitrogen catabolite repression in yeast  

E-print Network

Structure theorems and the dynamics of nitrogen catabolite repression in yeast Erik M. Boczko catabolite repression (NCR) in yeast. A variety of mathematical ``structure'' theorems are described of nitrogen catabolite repression (NCR) in yeast, the power of the theory, its current limitations, and some

Gedeon, Tomas

400

Whole-genome Comparative Annotation and Regulatory Motif Discovery in Multiple Yeast Species  

E-print Network

Whole-genome Comparative Annotation and Regulatory Motif Discovery in Multiple Yeast Species these three yeast species to their close relative, S. cerevisiae. Genome-wide comparative analysis allowed than 90% of genes despite the large number of duplicated genes in the yeast genome, and the discovery

Kellis, Manolis

401

The yeast genome project identified approximately 6500 open reading frames (ORFs), some of which encode ubiquitous  

E-print Network

The yeast genome project identified approximately 6500 open reading frames (ORFs), some of which of the identified yeast proteins have unknown functions in mammals (Supek et al., 1996; Askwith and Kaplan, 1998). The function of many other ubiquitous proteins is still unknown, and disruption of their ORF in yeast results

Nelson, Nathan

402

Yeast and human TFIIDs are interchangeable for the response to acidic  

E-print Network

Yeast and human TFIIDs are interchangeable for the response to acidic transcriptional activators, Boston, Massachusetts 02115 USA Previous work showed that human TFIID fails to support yeast cell growth, although it is nearly identical to yeast TFIID in a carboxy-terminal region of the molecule that suffices

403

Yeast Oligo-Mediated Genome Engineering (YOGE) James E. DiCarlo,,  

E-print Network

Yeast Oligo-Mediated Genome Engineering (YOGE) James E. DiCarlo,, Andrew J. Conley,,§ Merja production host Saccharomyces cerevisiae, which we call yeast oligo-mediated genome engineering (YOGE of dozens of cells. We demonstrate the robustness of our approach in three divergent yeast strains

Church, George M.

404

Analysis of Yeast's ORF Upstream Regions by Parallel Processing, Microarrays, and Computational Methods  

E-print Network

Analysis of Yeast's ORF Upstream Regions by Parallel Processing, Microarrays, and Computational­ gions, gene regulation, DNA­microarrays, yeast, motifs, Markov models Abstract We use a network of workstations to compute all pairwise alignments of the 500 bp upstream regions of 6,225 yeast ORFs (Open

Kibler, Dennis F.

405

Yeast UCS proteins promote actomyosin interactions and limit myosin turnover in cells  

E-print Network

Yeast UCS proteins promote actomyosin interactions and limit myosin turnover in cells Matthew Lord for the conserved family of UCS proteins: helping to fold myosin motor proteins and stimulating the motor function of folded myosins. We examined both func- tions in yeast. The fission yeast UCS protein (Rng3p) concentrates

406

When transcriptome meets metabolome: fast cellular responses of yeast to sudden relief of glucose  

E-print Network

When transcriptome meets metabolome: fast cellular responses of yeast to sudden relief of glucose; Gasch and Werner-Washburne, 2002). In the yeast Saccharomyces cerevisiae, nutrient responses have been most extensively studied for glucose, the preferred carbon and energy source for this yeast (see

Shmulevich, Ilya

407

Yeasts and their possible beneficial and negative effects on the quality of dairy products  

Microsoft Academic Search

This review deals with yeasts and their potential use as starter cultures in dairy products as well as their role as spoilage organisms. The taxonomy of relevant yeasts is described, with emphasis on molecular techniques and simplified identification systems applicable to industry. Quantitative assessment of undesirable yeast contamination is discussed with regard to present requirements for quality assurance in dairies.

Mogens Jakobsen; Judy Narvhus

1996-01-01

408

In yeast, Ca 2+ and octylguanidine interact with porin (VDAC) preventing the mitochondrial permeability transition  

Microsoft Academic Search

In yeast, Ca2+ and long chain alkylguanidines interact with mitochondria modulating the opening of the yeast mitochondrial unspecific channel. Mammalians possess a similar structure, the mitochondrial permeability transition pore. The composition of these pores is under debate. Among other components, the voltage-dependent anion channel has been proposed as a component of either pore. In yeast from an industrial strain, octylguanidine

Manuel Gutiérrez-Aguilar; Victoriano Pérez-Vázquez; Odile Bunoust; Stéphen Manon; Michel Rigoulet; Salvador Uribe

2007-01-01

409

Optimal Operation of Baker's Yeast Fermenta-tion in the Presence of Uncertainty  

E-print Network

of determining the optimal feeding policy for a fed-batch fermentation for the production of Baker's yeast the simulator as if it were the real process. These two methods are implemented on a Baker's yeast fermentation (palanki@eng.fsu.edu). #12;for a fed-batch fermentation for the production of Baker's yeast in the presence

Palanki, Srinivas

410

Catabolism of benzene compounds by ascomycetous and basidiomycetous yeasts and yeastlike fungi  

Microsoft Academic Search

A literature review is given on growth of yeasts on benzene compounds and on the catabolic pathways involved. Additionally, a yeast collection was screened for assimilation of phenol and 3-hydroxybenzoic acid. Fifteen ascomycetous and thirteen basidiomycetous yeast species were selected and were tested for growth on 84 benzene compounds. It appeared that 63 of these compounds supported growth of one

Wouter J. Middelhoven; Hesselink van Suchtelenweg

1993-01-01

411

Stimulation of lactobacilli during alcoholic fermentation: action of sucrose hydrolysis by yeast  

Microsoft Academic Search

Summary Behaviour of lactic acid bacteria especially their stimulation in mixed culture with yeast was studied. In alcoholic fermentation of molasses worts, bacterial growth was stimulated as the yeast inoculum size increase. The consumption of monosaccharides (glucose and fructose) liberated during hydrolysis of sucrose by yeast is proposed as a major factor accounting for this phenomenon.

J. J. Essia Ngang; E. Wolniewicz; F. Letourneau; P. Villa

1992-01-01

412

Dry amyloid fibril assembly in a yeast prion peptide is mediated by long-lived structures  

E-print Network

Dry amyloid fibril assembly in a yeast prion peptide is mediated by long-lived structures sequences using two amyloidogenic peptides, one a polar sequence from the N terminus of the yeast prion Sup interface formation characterizes protofilament assembly in the yeast prions. Indeed, as the two sheets

Thirumalai, Devarajan

413

fluctuating structures A natively unfolded yeast prion monomer adopts an ensemble of collapsed and rapidly  

E-print Network

fluctuating structures A natively unfolded yeast prion monomer adopts an ensemble of collapsed reprints, see: Notes: #12;A natively unfolded yeast prion monomer adopts an ensemble of collapsed Lindquist, December 22, 2006 (sent for review December 5, 2006) The yeast prion protein Sup35

Lindquist, Susan

414

Pedobiologia 50 (2006) 341--345 Effect of inoculation with soil yeasts on  

E-print Network

Pedobiologia 50 (2006) 341--345 Effect of inoculation with soil yeasts on mycorrhizal symbiosis Arbuscular mycorrhizal fungi; Soil yeasts; Candida sake; Cryptococcus aerius; Williopsis californica; Maize Summary Interactions between arbuscular mycorrhizal fungi (AMF) and soil yeasts were studied in a pot

Janouskova, Martina

415

Using fungi and yeasts to manage vegetable crop diseases  

Microsoft Academic Search

Vegetable crops are grown worldwide as a source of nutrients and fiber in the human diet. Fungal plant pathogens can cause devastation in these crops under appropriate environmental conditions. Vegetable producers confronted with the challenges of managing fungal pathogens have the opportunity to use fungi and yeasts as biological control agents. Several commercially available products have shown significant disease reduction

Zamir K. Punja; Raj S. Utkhede

2003-01-01

416

'Yeast mail': a novel Saccharomyces application (NSA) to encrypt messages.  

PubMed

The universal genetic code is used by all life forms to encode biological information. It can also be used to encrypt semantic messages and convey them within organisms without anyone but the sender and recipient knowing, i.e., as a means of steganography. Several theoretical, but comparatively few experimental, approaches have been dedicated to this subject, so far. Here, we describe an experimental system to stably integrate encrypted messages within the yeast genome using a polymerase chain reaction (PCR)-based, one-step homologous recombination system. Thus, DNA sequences encoding alphabetical and/or numerical information will be inherited by yeast propagation and can be sent in the form of dried yeast. Moreover, due to the availability of triple shuttle vectors, Saccharomyces cerevisiae can also be used as an intermediate construction device for transfer of information to either Drosophila or mammalian cells as steganographic containers. Besides its classical use in alcoholic fermentation and its modern use for heterologous gene expression, we here show that baker's yeast can thus be employed in a novel Saccharomyces application (NSA) as a simple steganographic container to hide and convey messages. PMID:25238077

Rosemeyer, Helmut; Paululat, Achim; Heinisch, Jürgen J

2014-09-01

417

MAP Kinase Pathways in the Yeast Saccharomyces cerevisiae  

PubMed Central

A cascade of three protein kinases known as a mitogen-activated protein kinase (MAPK) cascade is commonly found as part of the signaling pathways in eukaryotic cells. Almost two decades of genetic and biochemical experimentation plus the recently completed DNA sequence of the Saccharomyces cerevisiae genome have revealed just five functionally distinct MAPK cascades in this yeast. Sexual conjugation, cell growth, and adaptation to stress, for example, all require MAPK-mediated cellular responses. A primary function of these cascades appears to be the regulation of gene expression in response to extracellular signals or as part of specific developmental processes. In addition, the MAPK cascades often appear to regulate the cell cycle and vice versa. Despite the success of the gene hunter era in revealing these pathways, there are still many significant gaps in our knowledge of the molecular mechanisms for activation of these cascades and how the cascades regulate cell function. For example, comparison of different yeast signaling pathways reveals a surprising variety of different types of upstream signaling proteins that function to activate a MAPK cascade, yet how the upstream proteins actually activate the cascade remains unclear. We also know that the yeast MAPK pathways regulate each other and interact with other signaling pathways to produce a coordinated pattern of gene expression, but the molecular mechanisms of this cross talk are poorly understood. This review is therefore an attempt to present the current knowledge of MAPK pathways in yeast and some directions for future research in this area. PMID:9841672

Gustin, Michael C.; Albertyn, Jacobus; Alexander, Matthew; Davenport, Kenneth

1998-01-01

418

Spatial organization and dynamics of interphase yeast chromosomes  

NASA Astrophysics Data System (ADS)

Understanding how the genome is spatially organized is an important problem in cell biology, due to its key roles in gene expression and DNA recombination. Here we report on a combined experimental and theoretical study of the organization and dynamics of yeast chromosome III which has a functional role in the yeast life cycle, in particular, it is responsible for mating type switching. By imaging two fluorescent markers, one at the spindle pole body (SPB) and the other proximal to the HML locus that is involved in DNA recombination during mating type switching, we measured the cell to cell distribution of distances and the mean square displacement between the markers as a function of time. We compared our experimental results with a random-walk polymer model that takes into account tethering and confinement of chromosomes in the nucleus, and found that the model recapitulates the observed spatial and temporal organization of chromosome III in yeast in quantitative detail. The polymer model makes specific predictions for mating-type switching in yeast, and suggests new experiments to test them.

Avsaroglu, Baris; Gordon-Messer, Susannah; Fritsche, Miriam; Ham, Jungoh; Heermann, Dieter W.; Haber, James E.; Kondev, Jane

2012-02-01

419

Trehalose in yeast, stress protectant rather than reserve carbohydrate  

Microsoft Academic Search

Trehalose and glycogen are generally regarded as the two main reserve carbohydrates in yeast. However, several lines of evidence suggest that trehalose does not primarily function as a reserve but as a highly efficient protecting agent to maintain strutural integrity of the cytoplasm under environmental stress conditions.

Andres Wiemken

1990-01-01

420

Uptake of Cobalt, Lead, and Cadmium by Baker's Yeast.  

National Technical Information Service (NTIS)

The toxicity for and the uptake by Seccharomyces cerevisias of the essential trace element Co exp 2+ and the non essential elements Cd exp 2+ and Pb exp 2+ were compared. Inhibition of yeast growth is observed 4 hrs after addition of Co at concentrations ...

R. Heldwein, H. W. Tromballa, E. Broda

1977-01-01

421

The Inside-Out Mechanism of Dicers from Budding Yeasts  

E-print Network

,5 Dinshaw J. Patel,4,* and David P. Bartel1,2,3,* 1Whitehead Institute for Biomedical Research, 9 Cambridge-Kettering Cancer Center, New York, NY 10065, USA 5These authors contributed equally to this work *Correspondence both Dicer and Argonaute homologs. Nonetheless, other budding-yeast species, including Saccharomyces

Bartel, David

422

Evolution of linear chromosomes and multipartite genomes in yeast mitochondria  

E-print Network

Evolution of linear chromosomes and multipartite genomes in yeast mitochondria Matus Valach1 mitochondria contain linear (cir- cularly permuted) concatemers that are heterogeneous in size (termed, mitochondria of numerous organisms contain multipartite genome; i.e. fragmented into multiple (from few

Brejova, Brona

423

Nuclear Envelope Fission Is Linked to Cytokinesis in Budding Yeast  

Microsoft Academic Search

We have investigated the relationship between nuclear envelope fission and cytokinesis during mitotic cell division in budding yeast. By carrying out time-lapse and optical sectioning video microscopy analysis of cells that express green fluorescent protein (GFP)-tagged nuclear envelope and actomyosin ring components, we found that nuclear division is temporally coupled to cytokinesis. Light and electron microscopy analysis also showed that

John Lippincott; Rong Li

2000-01-01

424

Lithium acetate transformation of yeast Maitreya Dunham August 2004  

E-print Network

Lithium acetate transformation of yeast Maitreya Dunham August 2004 Original protocol from Katja until the OD600 is around 0.7-0.8 (~7 hours). Spin down the cells. Resuspend in 5 ml lithium acetate mix. Spin. Resuspend in 0.5 ml lithium acetate mix. Transfer to an eppendorf tube. Incubate 60 minutes

Dunham, Maitreya

425

Pathogenic Yeasts Cryptococcus neoformans and Candida albicans Produce Immunomodulatory Prostaglandins  

PubMed Central

Enhanced prostaglandin production during fungal infection could be an important factor in promoting fungal colonization and chronic infection. Host cells are one source of prostaglandins; however, another potential source of prostaglandins is the fungal pathogen itself. Our objective was to determine if the pathogenic yeasts Cryptococcus neoformans and Candida albicans produce prostaglandins and, if so, to begin to define the role of these bioactive lipids in yeast biology and disease pathogenesis. C. neoformans and C. albicans both secreted prostaglandins de novo or via conversion of exogenous arachidonic acid. Treatment with cyclooxygenase inhibitors dramatically reduced the viability of the yeast and the production of prostaglandins, suggesting that an essential cyclooxygenase like enzyme may be responsible for fungal prostaglandin production. A PGE series lipid was purified from both C. albicans and C. neoformans and was biologically active on both fungal and mammalian cells. Fungal PGEx and synthetic PGE2 enhanced the yeast-to-hypha transition in C. albicans. Furthermore, in mammalian cells, fungal PGEx down-modulated chemokine production, tumor necrosis factor alpha production, and splenocyte proliferation while up-regulating interleukin 10 production. These are all activities previously documented for mammalian PGE2. Thus, eicosanoids are produced by pathogenic fungi, are critical for growth of the fungi, and can modulate host immune functions. The discovery that pathogenic fungi produce and respond to immunomodulatory eicosanoids reveals a virulence mechanism that has potentially great implications for understanding the mechanisms of chronic fungal infection, immune deviation, and fungi as disease cofactors. PMID:11292712

Noverr, Mairi C.; Phare, Susan M.; Toews, Galen B.; Coffey, Michael J.; Huffnagle, Gary B.

2001-01-01

426

Genetic control of cell size at cell division in yeast  

Microsoft Academic Search

A temperature-sensitive mutant strain of the fission yeast Schizosaccharomyces pombe has been isolated which divides at half the size of the wild type. Study of this strain suggests that there is a cell size control over DNA synthesis and a second control acting on nuclear division.

P. Nurse; R. K. Mortimer; J. Culotti; M. Culotti

1975-01-01

427

Modelling neurodegeneration in Saccharomyces cerevisiae: why cook with baker's yeast?  

Microsoft Academic Search

In ageing populations, neurodegenerative diseases increase in prevalence, exacting an enormous toll on individuals and their communities. Multiple complementary experimental approaches are needed to elucidate the mechanisms underlying these complex diseases and to develop novel therapeutics. Here, we describe why the budding yeast Saccharomyces cerevisiae has a unique role in the neurodegeneration armamentarium. As the best-understood and most readily analysed

Vikram Khurana; Susan Lindquist

2010-01-01

428

Redox Regulation of Yeast Flavin-Containing Monooxygenase  

E-print Network

Redox Regulation of Yeast Flavin-Containing Monooxygenase Jung-Keun Suh, Lawrence L. Poulsen 339 participate in the redox regulation. Cys 353 is the principal residue in the re- dox that is fully inhibitory. © 2000 Academic Press Key Words: yFMO; flavo-enzyme; redox regulation; mutagenesis

429

Molecular and phenotypic identification of the yeast pathogen Candida dubliniensis  

Microsoft Academic Search

Candida dubliniensis is an emerging yeast pathogen generally misclassified as Candida albicans by standard diagnostic procedures. This study examined the efficiency of molecular identification, based on a discriminative PCR test, in a prospective study on the prevalence of C. dubliniensis among 103 oropharyngeal isolates from HIV-infected individuals or transplant recipients, and 30 vaginal isolates. All of the isolates had been

Oliver Kurzai; Hans-Christian Korting; Dag Harmsen; Wilfried Bautsch; Michael Molitor; Matthias Frosch; Fritz A. Mühlschlegel

2000-01-01

430

Extrachromosomal psi+ determinant suppresses nonsense mutations in yeast.  

PubMed Central

The extrachromosomal psi+ determinant in the yeast Saccharomyces cerevisiae enhanced the expression of Mendelian UAA suppressors by 6- to 10-fold. The psi+ determinant by itself is a weak UAA suppressor that caused the production of approximately 1% of the normal level of iso-1-cytochrome c in a strain containing the UAA mutation cycl-72. PMID:225301

Liebman, S W; Sherman, F

1979-01-01

431

Glucose-sensing and -signalling mechanisms in yeast  

Microsoft Academic Search

Glucose has dramatic effects on the regulation of carbon metabolism and on many other properties of yeast cells. Several sensing and signalling pathways are involved. For many years attention has focussed on the main glucose-repression pathway which is responsible for the downregulation of respiration, gluconeogenesis and the transport and catabolic capacity of alternative sugars during growth on glucose. The hexokinase

Filip Rolland; Joris Winderickx; Johan M Thevelein

2002-01-01

432

Transcription of the yeast mitochondrial genome requires cyclic AMP  

Microsoft Academic Search

Using various mutant strains and nutritional manipulations, we investigated a potential role for cyclic AMP (cAMP) in the regulation of mitochondrial (mt) gene expression in the yeast Saccharomyces cerevisiae. In RAS mutants known to have either abnormally low or high cellular levels of this nucleotide, we show that both mt transcription rate and overall mt transcript levels vary directly with

Catherine M. McEntee; Robin Cantwell; Mahboob U. Rahman; Alan P. Hudson

1993-01-01

433

Genome Sequence of the Yeast Cyberlindnera fabianii (Hansenula fabianii)  

PubMed Central

The yeast Cyberlindnera fabianii is used in wastewater treatment, fermentation of alcoholic beverages, and has caused blood infections. To assist in the accurate identification of this species, and to determine the genetic basis for properties involved in fermentation and water treatment, we sequenced and annotated the genome of C. fabianii (YJS4271). PMID:25103752

Freel, Kelle C.; Sarilar, Veronique; Neuveglise, Cecile; Devillers, Hugo; Friedrich, Anne

2014-01-01

434

Genome Sequence of the Oleaginous Yeast Rhodotorula glutinis ATCC 204091  

PubMed Central

Rhodotorula glutinis ATCC 204091 is an oleaginous oxidative red yeast that can accumulate lipids to >50% of its biomass when grown with appropriate carbon and nitrogen ratios. It produces a red pigment consisting of useful antioxidants, such as carotenoids, torulene, and torularhodin, when cultivated under carbon-deficient conditions. PMID:24526636

Paul, Debarati; Magbanua, Zenaida; Arick, Mark; French, Todd; Bridges, Susan M.; Burgess, Shane C.

2014-01-01

435

MEIOTIC RECOMBINATION AND SPORULATION IN REPAIRDEFICIENT STRAINS OF YEAST  

Microsoft Academic Search

A genetic system designed to monitor recombination and sporulation in various repair-deficient yeast strains was constructed. Variously heterozygous at seven or eight sites distributed across the genome, the system facilitated sensitive detection of changes in frequency or pattern of meiotic recombina- tion. Ten rad mutants sensitive primarily to UV-irradiation and without ter- minal blocks in the sporulation process were studied.

ELIZABETH L. DOWLING; DANIEL H. MALONEY; SEYMOUR FOGEL

436

Quantitative Analysis of the Effective Functional Structure in Yeast Glycolysis  

E-print Network

Quantitative Analysis of the Effective Functional Structure in Yeast Glycolysis Ildefonso M. De la for the glycolytic enzymes in dissipative conditions we have analyzed different catalytic patterns using of the irreversible enzymes. In addition to the classical topological structure characterized by the specific location

Cortes, Jesus

437

A mathematical model for cell size control in fission yeast.  

PubMed

Experimental investigations of cell size control in fission yeast Schizosaccharomyces pombe have illustrated that the cell cycle features 'sizer' and 'timer' phases which are distinguished by a growth rate changing point. Based on current biological knowledge of fission yeast size control, we propose here a model of ordinary differential equations (ODEs) for a possible explanation of the facts and control mechanism which is coupled with the cell cycle. Simulation results of the ODE model are demonstrated to agree with experimental data for the wild type and the cdc2-33 mutant. We show that the coupling of cell growth to cell division by translational control may account for observed properties of size control in fission yeast. As the translational control in the expression of cycle proteins Cdc13 and Cdc25 constructs positive feedback loops, the dynamical activities of the key components undergoes a rapid rising after a preliminary stage of slow increase. The coupling of this dynamical behavior to the elongation of the cell naturally gives rise to a rate change point and to 'sizer' and 'timer' phases, which characterize the cell cycle of fission yeast. PMID:20303984

Li, Bo; Shao, Bin; Yu, Chenlu; Ouyang, Qi; Wang, Hongli

2010-06-01

438

Global Transcriptional Responses of Fission Yeast to Environmental Stress  

Microsoft Academic Search

We explored transcriptional responses of the fission yeast Schizosaccharomyces pombe to various environmental stresses. DNA microarrays were used to characterize changes in expression pro- files of all known and predicted genes in response to five stress conditions: oxidative stress caused by hydrogen peroxide, heavy metal stress caused by cadmium, heat shock caused by temperature increase to 39°C, osmotic stress caused

Dongrong Chen; W. Mark Toone; Juan Mata; Rachel Lyne; Gavin Burns; Katja Kivinen; Alvis Brazma; Nic Jones

2003-01-01

439

Biodiversity of yeasts and filamentous microfungi in terrestrial Antarctic ecosystems  

Microsoft Academic Search

Fungal biodiversity in Antarctic terrestrial ecosystems increases with the availability of water and energy, but cannot now be precisely described because of problems with identification and questions us to what organisms are truly indigenous. Yeasts probably predominate on continental Antarctica, while other microfungi usually do so in maritime and sub-Antarctica. Lists of nematophagous species and of microfungal species reported from

H. S. Vishniac

1996-01-01

440

Succinic Acid Synthesis by Ethanol-Grown Yeasts  

Microsoft Academic Search

Summary The synthesis of succinic acid in ethanol-containing media has been tested in 32 yeasts of different genera (Debaryomyces, Candida, Pichia, Saccharomyces, Torulopsis). The capability of succinic acid synthesis was revealed in 29 strains, from which two most effective produ- cers were selected. When grown in a fermentor under high aeration in mineral medium with pulsed addition of ethanol, the

Svetlana V. Kamzolova; Alsu I. Yusupova; Emiliya G. Dedyukhina; Tatiana I. Chistyakova; Tatiana M. Kozyreva; Igor G. Morgunov

2009-01-01

441

Characterization of a unique ethanologenic yeast capable of fermenting galactose  

Microsoft Academic Search

The hexose and pentose sugars common to substrate mixtures used in yeast-catalyzed industrial processes are often affected by carbon catabolite repression, in which the presence of glucose significantly delays the consumption of other sugars. Screening experiments performed with wild-type Saccharomyces cerevisiae strains have identified a strain that exhibits exceptional fermentative performance on galactose, completely exhausting the sugar in significantly less

Jeffrey D Keating; Jamie Robinson; Rodney J Bothast; John N Saddler; Shawn D Mansfield

2004-01-01

442

Key words: STREAMLINE, yeast, scale up, automation, sanitization.  

E-print Network

Key words: STREAMLINE, yeast, scale up, automation, sanitization. Abstract This application note was evaluated by performing a sanitization study in which the column and system were challenged with culture consistent throughout the different scales. Cleaning-in-place (CIP) and sanitization-in-place (SIP) were

Lebendiker, Mario

443

The fission yeast UVDR DNA repair pathway is inducible  

Microsoft Academic Search

In addition to nucleotide excision repair (NER), the fission yeast Schizosaccharomyces pombe pos- sesses a UV damage endonuclease (UVDE) for the excision of cyclobutane pyrimidine dimers and 6-4 pyrimidine pyrimidones. We have previously de- scribed UVDE as part of an alternative excision repair pathway, UVDR, for UV damage repair. The existence of two excision repair processes has long been postulated

Scott Davey; Monica L. Nass; Jasmine V. Ferrer; Khalifah Sidik; Andrew Eisenberger; David L. Mitchell; Greg A. Freyer

1997-01-01

444

Enhanced Arsenic Accumulation by Engineered Yeast Cells Expressing  

E-print Network

ARTICLE Enhanced Arsenic Accumulation by Engineered Yeast Cells Expressing Arabidopsis thaliana occurring peptides with high-binding capabilities for a wide range of heavy metals including arsenic (As As accumulation as compared to the control strain under a wide range of As concentrations. For the high-arsenic

Chen, Wilfred

445

Phenotypic and genotypic identification of yeasts from cheese  

Microsoft Academic Search

Eighty-five yeast strains isolated from different cheeses of Austria, Denmark, France, Germany, and Italy were identified using physiological methods and genotypically using random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) analysis. Good congruence was found between the phenotypic and genotypic data for 39 of the isolates. However, 26 isolates of Geotrichum could only be identified to the species level using

Hansjörg Prillinger; Orsolya Molnár; Frieda Eliskases-Lechner; Ksenija Lopandic

1999-01-01

446

Ethanol production at elevated temperatures using encapsulation of yeast.  

PubMed

The ability of macroencapsulated Saccharomyces cerevisiae CBS 8066 to produce ethanol at elevated temperatures was investigated in consecutive batch and continuous cultures. Prior to cultivation yeast was confined inside alginate-chitosan capsules composed of an outer semi-permeable membrane and an inner liquid core. The encapsulated yeast could successfully ferment 30 g/L glucose and produce ethanol at a high yield in five consecutive batches of 12 h duration at 42°C, while freely suspended yeast was completely inactive already in the third batch. A high ethanol production was observed also through the first 48 h at 40°C during continuous cultivation at D=0.2 h(-1) when using encapsulated cells. The ethanol production slowly decreased in the following days at 40°C. The ethanol production was also measured in a continuous cultivation in which the temperature was periodically increased to 42-45°C and lowered to 37°C again in periods of 12h. Our investigation shows that a non-thermotolerant yeast strain improved its heat tolerance upon encapsulation, and could produce ethanol at temperatures as high as 45°C for a short time. The possibility of performing fermentations at higher temperatures would greatly improve the enzymatic hydrolysis in simultaneous saccharification and fermentation (SSF) processes and thereby make the bioethanol production process more economically feasible. PMID:21807041

Ylitervo, Päivi; Franzén, Carl Johan; Taherzadeh, Mohammad J

2011-10-20

447

Yeast Aquaglyceroporins Use the Transmembrane Core to Restrict Glycerol Transport*  

PubMed Central

Aquaglyceroporins are transmembrane proteins belonging to the family of aquaporins, which facilitate the passage of specific uncharged solutes across membranes of cells. The yeast aquaglyceroporin Fps1 is important for osmoadaptation by regulating intracellular glycerol levels during changes in external osmolarity. Upon high osmolarity conditions, yeast accumulates glycerol by increased production of the osmolyte and by restricting glycerol efflux through Fps1. The extended cytosolic termini of Fps1 contain short domains that are important for regulating glycerol flux through the channel. Here we show that the transmembrane core of the protein plays an equally important role. The evidence is based on results from an intragenic suppressor mutation screen and domain swapping between the regulated variant of Fps1 from Saccharomyces cerevisiae and the hyperactive Fps1 ortholog from Ashbya gossypii. This suggests a novel mechanism for regulation of glycerol flux in yeast, where the termini alone are not sufficient to restrict Fps1 transport. We propose that glycerol flux through the channel is regulated by interplay between the transmembrane helices and the termini. This mechanism enables yeast cells to fine-tune intracellular glycerol levels at a wide range of extracellular osmolarities. PMID:22593571

Geijer, Cecilia; Ahmadpour, Doryaneh; Palmgren, Madelene; Filipsson, Caroline; Klein, Dagmara Medrala; Tamas, Markus J.; Hohmann, Stefan; Lindkvist-Petersson, Karin

2012-01-01

448

CLUSTER, FUNCTION AND PROMOTER: ANALYSIS OF YEAST EXPRESSION ARRAY  

E-print Network

CLUSTER, FUNCTION AND PROMOTER: ANALYSIS OF YEAST EXPRESSION ARRAY J. ZHU, M. Q. ZHANG Cold Spring Harbor Lab, P. O. Box 100 Cold Spring Harbor, NY 11724 Gene clusters could be derived based on expression profiles, function categorization and promoter regions. To obtain thorough understanding of gene expression

449

Systems-level engineering of nonfermentative metabolism in yeast.  

PubMed

We designed and experimentally validated an in silico gene deletion strategy for engineering endogenous one-carbon (C1) metabolism in yeast. We used constraint-based metabolic modeling and computer-aided gene knockout simulations to identify five genes (ALT2, FDH1, FDH2, FUM1, and ZWF1), which, when deleted in combination, predicted formic acid secretion in Saccharomyces cerevisiae under aerobic growth conditions. Once constructed, the quintuple mutant strain showed the predicted increase in formic acid secretion relative to a formate dehydrogenase mutant (fdh1 fdh2), while formic acid secretion in wild-type yeast was undetectable. Gene expression and physiological data generated post hoc identified a retrograde response to mitochondrial deficiency, which was confirmed by showing Rtg1-dependent NADH accumulation in the engineered yeast strain. Formal pathway analysis combined with gene expression data suggested specific modes of regulation that govern C1 metabolic flux in yeast. Specifically, we identified coordinated transcriptional regulation of C1 pathway enzymes and a positive flux control coefficient for the branch point enzyme 3-phosphoglycerate dehydrogenase (PGDH). Together, these results demonstrate that constraint-based models can identify seemingly unrelated mutations, which interact at a systems level across subcellular compartments to modulate flux through nonfermentative metabolic pathways. PMID:19564482

Kennedy, Caleb J; Boyle, Patrick M; Waks, Zeev; Silver, Pamela A

2009-09-01

450

Glucose depletion causes haploid invasive growth in yeast  

E-print Network

depletion. In the absence of glucose (or other fermentable sugar), individual cells adopted a nonaxial have the ability to adopt two growth forms, a vegetative (yeast) form and a pseudohyphal or filamentous vegetative growth, in which cells are round and bud in a bipolar fashion, to pseudohyphal growth, in which

Cullen, Paul J.

451

Kinetic properties of glycerophosphate oxidase isolated from dry baker's yeast  

Microsoft Academic Search

The glycerophosphate oxidase is a flavoprotein responsible for the catalysis of the oxidation of the glycerophosphate to dihydroxyacetone phosphate, through the reduction of the oxygen to hydrogen peroxide. The glycerophosphate oxidase from baker's yeast was specific for l-?-glycerol phosphate. It was estimated by monitoring the consumption of oxygen with an oxygraph. An increase of 32% in consumption of oxygen was

Luciana Amade Camargo; Maria Henriques Lourenço Ribeiro; Maristela de Freitas Sanches Peres; Edwil Aparecida de Lucca Gattás

2008-01-01

452

Evolution of protein kinase signaling from yeast to man  

Microsoft Academic Search

Protein phosphorylation controls many cellular processes, especially those involved in intercellular communication and coordination of complex functions. To explore the evolution of protein phosphorylation, we compared the protein kinase complements (‘kinomes’) of budding yeast, worm and fly, with known human kinases. We classify kinases into putative orthologous groups with conserved functions and discuss kinase families and pathways that are unique,

Gerard Manning; Gregory D Plowman; Tony Hunter; Sucha Sudarsanam

2002-01-01

453

Early Replication of Short Telomeres in Budding Yeast  

E-print Network

Early Replication of Short Telomeres in Budding Yeast Alessandro Bianchi1, * and David Shore1 1.bianchi@molbio.unige.ch DOI 10.1016/j.cell.2007.01.041 SUMMARY The maintenance of an appropriate number of telomere repeats by telomerase is essential for proper chromosome protection. The action of telomerase at the telomere terminus

Halazonetis, Thanos

454

Yeast: A General Purpose Event-Action System  

Microsoft Academic Search

Distributed networks of personal workstations are becoming the dominant computing environment for software development organizations. Many cooperative activities that are carried out in such environments are particularly well suited for automated support. Taking the point of view that such activities are modeled most naturally as the occurrence of events requiring actions to be performed, we developed a system called Yeast

Balachander Krishnamurthy; David S. Rosenblum

1995-01-01

455

A genomic analysis of chronological longevity factors in budding yeast  

PubMed Central

Chronological life span (CLS) has been studied as an aging paradigm in yeast. A few conserved aging genes have been identified that modulate both chronological and replicative longevity in yeast as well as longevity in the nematode Caenorhabditis elegans; however, a comprehensive analysis of the relationship between genetic control of chronological longevity and aging in other model systems has yet to be reported. To address this question, we performed a functional genomic analysis of chronological longevity for 550 single-gene deletion strains, which accounts for approximately 12% of the viable homozygous diploid deletion strains in the yeast ORF deletion collection. This study identified 33 previously unknown determinants of CLS. We found no significant enrichment for enhanced CLS among deletions corresponding to yeast orthologs of worm aging genes or among replicatively long-lived deletion strains, although a trend toward overlap was noted. In contrast, a subset of gene deletions identified from a screen for reduced acidification of culture media during growth to stationary phase was enriched for increased CLS. These results suggest that genetic control of CLS under the most commonly utilized assay conditions does not strongly overlap with longevity determinants in C. elegans, with the existing confined to a small number of genetic pathways. These data also further support the model that acidification of the culture medium plays an important role in survival during chronological aging in synthetic medium, and suggest that chronological aging studies using alternate medium conditions may be more informative with regard to aging of multicellular eukaryotes. PMID:21447998

Olsen, Brady

2011-01-01

456

Amperometric estimation of BOD by using living immobilized yeasts  

Microsoft Academic Search

A microbial electrode consisting of immobilized living whole cells of yeasts, porous membrane and an oxygen electrode was prepared for continuous estimation of biochemical oxygen demand (BOD). Immobilized Trichosporon cutaneum was employed for the microbial electrode sensor for BOD. When a sample solution containing the equivalent amount of glucose and glutamic acid was injected into the sensor system, the current

Motohiko Hikuma; Hiroshi Suzuki; Yakeo Yasuda; Isao Karube; Shuichi Suzuki

1979-01-01

457

Original article Effect of chromium yeast supplementation on performance,  

E-print Network

Original article Effect of chromium yeast supplementation on performance, reproduction and immune macrophages when control and Cr-supplemented sows were compared. (© Elsevier / Inra) chromium / immune. (@ Elsevier / Inra) chrome / réponse immunitaire / porc 1. INTRODUCTION Chromium (Cr) influences several

Boyer, Edmond

458

HeritableRemodelingofYeastMulticellularity by an Environmentally Responsive Prion  

E-print Network

HeritableRemodelingofYeastMulticellularity by an Environmentally Responsive Prion Daniel L. Holmes.cell.2013.02.026 SUMMARY Prion proteins undergo self-sustaining conforma- tional conversions that heritably is translated into pheno- type. But the breadth of prion influences on biology and their evolutionary

Zhang, Jianzhi

459

A molecular genetic system for the pathogenic yeast Candida dubliniensis  

Microsoft Academic Search

Candida dubliniensis is a recently described pathogenic yeast of the genus Candida that is closely related to Candida albicans but differs from it in several phenotypic and genotypic characteristics, including putative virulence traits, which may explain differences in the spectrum of diseases caused by the two species. In contrast to C. albicans, a molecular genetic system to study virulence of

Peter Staib; Sonja Michel; Gerwald Köhler; Joachim Morschhäuser

2000-01-01

460

Evaluation and Properties of the Budding Yeast Phosphoproteome*  

PubMed Central

We have assembled a reliable phosphoproteomic data set for budding yeast Saccharomyces cerevisiae and have investigated its properties. Twelve publicly available phosphoproteome data sets were triaged to obtain a subset of high-confidence phosphorylation sites (p-sites), free of “noisy” phosphorylations. Analysis of this combined data set suggests that the inventory of phosphoproteins in yeast is close to completion, but that these proteins may have many undiscovered p-sites. Proteins involved in budding and protein kinase activity have high numbers of p-sites and are highly over-represented in the vast majority of the yeast phosphoproteome data sets. The yeast phosphoproteome is characterized by a few proteins with many p-sites and many proteins with a few p-sites. We confirm a tendency for p-sites to cluster together and find evidence that kinases may phosphorylate off-target amino acids that are within one or two residues of their cognate target. This suggests that the precise position of the phosphorylated amino acid is not a stringent requirement for regulatory fidelity. Compared with nonphosphorylated proteins, phosphoproteins are more ancient, more abundant, have longer unstructured regions, have more genetic interactions, more protein interactions, and are under tighter post-translational regulation. It appears that phosphoproteins constitute the raw material for pathway rewiring and adaptation at various evolutionary rates. PMID:22286756

Amoutzias, Grigoris D.; He, Ying; Lilley, Kathryn S.; Van de Peer, Yves; Oliver, Stephen G.

2012-01-01

461

Hsp70 Structure, Function, Regulation and Influence on Yeast Prions  

PubMed Central

Heat shock proteins protect cells from various conditions of stress. Hsp70, the most ubiquitous and highly conserved Hsp, helps proteins adopt native conformation or regain function after misfolding. Various co-chaperones specify Hsp70 function and broaden its substrate range. We discuss Hsp70 structure and function, regulation by co-factors and influence on propagation of yeast prions. PMID:19519514

Sharma, D.; Masison, D. C.

2009-01-01

462

Production of folates by yeasts in Tanzanian fermented togwa.  

PubMed

We have investigated the impact of different yeasts and fermentation time on folate content and composition in a fermented maize-based porridge, called togwa, consumed in rural areas in Tanzania. The yeasts studied, originally isolated from indigenous togwa, belong to Issatchenkia orientalis, Pichia anomala, Saccharomyces cerevisiae, Klyveromyces marxianus and Candida glabrata. The main folate forms found, detected and quantified by HPLC during the fermentations were 5-methyl-tetrahydrofolate (5-CH(3)-H(4)folate) and tetrahydrofolate (H(4)folate). The content of H(4)folate, per unit togwa, remained fairly stable at a low level throughout the experiment for all strains, whereas the 5-CH(3)-H(4)folate concentration was highly dependent on yeast strain as well as on fermentation time. The highest folate concentration was found after 46 h of fermentation with C. glabrata (TY26) (6.91+/-0.14 microg 100 mL(-1)), corresponding to a 23-fold increase compared with unfermented togwa. The cell concentration per se could not predict the togwa folate level, as shown by the much higher specific folate content (g folate CFU(-1)) in the S. cerevisiae strain (TY08) compared with the other species tested. This study provides useful data when trying to maximize folate content in togwa as well as in other yeast-fermented products. PMID:18547328

Hjortmo, Sofia B; Hellström, Andreas M; Andlid, Thomas A

2008-08-01

463

Global Mapping of the Yeast Genetic Interaction Network  

Microsoft Academic Search

A genetic interaction network containing ~1000 genes and ~4000 interactions was mapped by crossing mutations in 132 different query genes into a set of ~4700 viable gene yeast deletion mutants and scoring the double mutant progeny for fitness defects. Network connectivity was predictive of function because interactions often occurred among functionally related genes, and similar patterns of interactions tended to

Amy Hin Yan Tong; Guillaume Lesage; Gary D. Bader; Huiming Ding; Hong Xu; Xiaofeng Xin; James Young; Gabriel F. Berriz; Renee L. Brost; Michael Chang; YiQun Chen; Xin Cheng; Gordon Chua; Helena Friesen; Debra S. Goldberg; Jennifer Haynes; Christine Humphries; Grace He; Shamiza Hussein; Lizhu Ke; Nevan Krogan; Zhijian Li; Joshua N. Levinson; Hong Lu; Patrice Ménard; Christella Munyana; Ainslie B. Parsons; Owen Ryan; Raffi Tonikian; Tania Roberts; Anne-Marie Sdicu; Jesse Shapiro; Bilal Sheikh; Bernhard Suter; Sharyl L. Wong; Lan V. Zhang; Hongwei Zhu; Christopher G. Burd; Sean Munro; Chris Sander; Jasper Rine; Jack Greenblatt; Matthias Peter; Anthony Bretscher; Graham Bell; Frederick P. Roth; Grant W. Brown; Brenda Andrews; Howard Bussey; Charles Boone

2004-01-01

464

The complete DNA sequence of yeast chromosome III  

Microsoft Academic Search

The entire DNA sequence of chromosome III of the yeast Saccharomyces cerevisiae has been determined. This is the first complete sequence analysis of an entire chromosome from any organism. The 315-kilobase sequence reveals 182 open reading frames for proteins longer than 100 amino acids, of which 37 correspond to known genes and 29 more show some similarity to sequences in

S. G. Oliver; Q. J. M. van der Aart; M. L. Agostoni-Carbone; M. Aigle; L. Alberghina; D. Alexandraki; G. Antoine; R. Anwar; J. P. G. Ballesta; P. Benit; G. Berben; E. Bergantino; N. Biteau; P. A. Bolle; M. Bolotin-Fukuhara; A. Brown; J. M. Buhler; C. Carcano; G. Carignani; H. Cederberg; R. Chanet; R. Contreras; M. Crouzet; B. Daignan-Fornier; E. Defoor; M. Delgado; J. Demolder; C. Doira; E. Dubois; B. Dujon; A. Dusterhoft; D. Erdmann; M. Esteban; F. Fabre; C. Fairhead; G. Faye; H. Feldmann; W. Fiers; M. C. Francingues-Gaillard; L. Franco; L. Frontali; H. Fukuhara; L. J. Fuller; P. Galland; M. E. Gent; D. Gigot; V. Gilliquet; N. Glansdorff; A. Goffeau; M. Grenson; P. Grisanti; L. A. Grivell; M. de Haan; M. Haasemann; D. Hatat; J. Hoenicka; J. Hegemann; C. J. Herbert; F. Hilger; S. Hohmann; C. P. Hollenberg; K. Huse; F. Iborra; K. J. Indje; K. Isono; C. Jacq; M. Jacquet; C. M. James; J. C. Jauniaux; Y. Jia; A. Jimenez; A. Kelly; U. Kleinhans; P. Kreisl; G. Lanfranchi; C. Lewis; C. G. Vanderlinden; G. Lucchini; K. Lutzenkirchen; M. J. Maat; L. Mallet; G. Mannhaupet; E. Martegani; A. Mathieu; C. T. C. Maurer; D. McConnell; R. A. McKee; F. Messenguy; H. W. Mewes; F. Molemans; M. A. Montague; M. Muzi Falconi; L. Navas; C. S. Newlon; D. Noone; C. Pallier; L. Panzeri; B. M. Pearson; J. Perea; P. Philippsen; A. Pierard; R. J. Planta; P. Plevani; B. Poetsch; F. Pohl; B. Purnelle; M. Ramezani Rad; S. W. Rasmussen; A. Raynal; M. Remacha; P. Richterich; A. B. Roberts; F. Rodriguez; E. Sanz; I. Schaaff-Gerstenschlager; B. Scherens; B. Schweitzer; Y. Shu; J. Skala; P. P. Slonimski; F. Sor; C. Soustelle; R. Spiegelberg; L. I. Stateva; H. Y. Steensma; S. Steiner; A. Thierry; G. Thireos; M. Tzermia; L. A. Urrestarazu; G. Valle; I. Vetter; J. C. van Vliet-Reedijk; M. Voet; G. Volckaert; P. Vreken; H. Wang; J. R. Warmington; D. von Wettstein; B. L. Wicksteed; C. Wilson; H. Wurst; G. Xu; A. Yoshikawa; F. K. Zimmermann; J. G. Sgouros

1992-01-01

465

Yeast opsonisation in children with chronic diarrhoeal states  

Microsoft Academic Search

Four patients with defective yeast opsonisation and protracted diarrhoea are reported. Plasma infusions improved the opsonising function in all 4 and the diarrhoea in 3. This immunological abnormality was assessed in 100 sequential patients with chronic diarrhoea associated with various gastrointestinal disorders; 52 with protracted diarrhoea and failure to thrive of undetermined cause, 26 with 'toddler diarrhoea', 8 with coeliac

D C Candy; V F Larcher; J H Tripp; J T Harries; B A Harvey; J F Soothill

1980-01-01

466

Cellular/Molecular Altered NMDA Receptor Trafficking in a Yeast  

E-print Network

Cellular/Molecular Altered NMDA Receptor Trafficking in a Yeast Artificial Chromosome Transgenic of Psychiatry, 3Centre for Molecular Medicine and Therapeutics, 4Department of Medical Genetics, 5Child/microsome-enrichedfraction,andcoimmunoprecipitationexperimentsdemonstratedanincreasedproportionofNR1C2 isoforms associated with NR2 subunits, which may contribute to faster forward trafficking

Contractor, Anis

467

Multiple Locus Linkage Analysis of Genomewide Expression in Yeast  

E-print Network

Multiple Locus Linkage Analysis of Genomewide Expression in Yeast John D. Storey1* , Joshua M. Akey studies have investigated the role of genetic variation in transcription by applying traditional linkage linkages, where we have allowed for epistatic interactions. Pairs of jointly linking quantitative trait

Kruglyak, Leonid

468

Metabolic Regulation and Anticancer Drug Resistance in the Yeast  

E-print Network

. It owes its specificity against neoplasms due to the higher rate of nutrient uptake, RNA and DNA synthesis in yeast 14 1.1.1 Haploinsufficiency profiling 15 1.1.2 Homozygous deletion profiling 15 1.1.3 Plasmid arrest and DNA damage 21 3.1 DNA damage and DNA breaks 21 3.2 DNA repair mechanisms and DNA damage

469

Chromosome condensation and sister chromatid pairing in budding yeast  

Microsoft Academic Search

We have developed a fluorescent in situ hy- bridization (FISH) method to examine the structure of both natural chromosomes and small artificial chromo- somes during the mitotic cycle of budding yeast. Our results suggest that the pairing of sister chromatids: (a) occurs near the centromere and at multiple places along the chromosome arm as has been observed in other eukaryotic

Vincent Guacci; Eileen Hogan; Douglas Koshland

1994-01-01

470

Two-hybrid systematic screening of the yeast proteome.  

PubMed

The yeast two-hybrid system is a genetic method that detects protein-protein interactions. One application is the detection by library screening of new interactors of a protein of known function. In the August issue of Nature Genetics, Fromont-Racine et al. showed for the first time that the construction of the protein interaction map of a complex pathway, such as that of the mRNA splicing machinery, is now possible, because of the combination of recent technical improvements elaborated in several laboratories. With a yeast cell mating procedure that increases screen efficiency, they used their complex yeast genomic library of 5 x 10(6) clones to test 700 x 10(6) interactions against 15 proteins. They identified and classified 170 potential interactors, including approximately 70 proteins of previously unknown function. More than 25% of the interactors are probably biologically relevant. The achievements of Fromont-Racine et al. have opened the way to the systematic analysis of the protein interaction networks of the 6,000 open reading frames-yeast proteome. This task requires, however, automation of the library screens and creation of a two-hybrid library database. PMID:9504041

Lecrenier, N; Foury, F; Goffeau, A

1998-01-01

471

Yeast cells expressing differential levels of human or yeast DNA topoisomerase II: a potent tool for identification and characterization of topoisomerase II-targeting antitumour agents  

Microsoft Academic Search

Purpose: To identify and characterize the specificity and potency of topoisomerase II-interacting antitumour drugs in an in vivo\\u000a model utilizing the yeast Saccharomyces cerevisiae. Methods: Four yeast transformants were selected for the expression of either human or yeast DNA topoisomerase II at different, biologically\\u000a relevant, levels under the tight control of promoters of various strengths. Results: Analyses of 24 drugs

Benoît van Hille; Bridget T. Hill

1998-01-01

472

Kefir-yeast technology: Industrial scale-up of alcoholic fermentation of whey, promoted by raisin extracts, using kefir-yeast granular biomass  

Microsoft Academic Search

Industrial scale-up of whey fermentation, promoted by raisin extracts, using free kefir-yeast cells is reported. The fermented whey would be exploited as raw material to produce kefir-like whey-based drinks, potable and fuel alcohol, as well as kefir-yeast biomass for use as baker's yeast. The scale-up process involved the development of a technology transfer scheme from lab-scale experiments to a successive

Athanasios A. Koutinas; Ilias Athanasiadis; Argyro Bekatorou; Costas Psarianos; Maria Kanellaki; Nikolaos Agouridis; Georgios Blekas

2007-01-01

473

Processing and secretion of barley (1-3,1-4)-beta-glucanase in yeast.  

PubMed

DNA segments encoding signal peptides from mouse alpha-amylase, yeast acid phosphatase, and yeast invertase were fused in frame to a barley (1-3,1-4)-beta-glucanase cDNA gene and expressed in yeast cells under the control of the phosphoglycerate kinase gene promoter. Pure beta-glucanase is obtained by gel filtration of concentrated yeast cell supernatant. It was shown that the glucanase pre-protein was specifically processed and the mature protein efficiently secreted when the yeast invertase signal sequence directed secretion. PMID:2673277

Olsen, O; Thomsen, K K

1989-01-01

474

Dynamics of indigenous yeast populations during spontaneous fermentation of wines from Mendoza, Argentina.  

PubMed

Fermentation of wine is a complex microbial reaction, which involves the sequential development of various species of yeasts and lactic acid bacteria. Of these, yeasts are the main group responsible for alcoholic fermentation. The aim of this work was to study, under industrial conditions, the evolution of yeast populations and to describe the individual evolution of the most important yeasts during three spontaneous fermentations of Malbec musts from Argentina. This work shows the significant participation of non-Saccharomyces yeasts during spontaneous fermentation of musts, with the ubiquitous presence of three main species: Kloeckera apiculata, Candida stellata and Metschnikowia pulcherrima. PMID:15808358

Combina, M; Elía, A; Mercado, L; Catania, C; Ganga, A; Martinez, C

2005-04-01

475

Effects of yeast, fermentation time, and preservation methods on tarhana.  

PubMed

The physicochemical properties of tarhana soup produced with different dough treatments, fermentation times, and preservation methods were examined. Tarhana doughs were prepared with yogurt (control) or baker's yeast (Saccharomyces cerevisiae) and fermented for 3 days. Samples were taken at 24, 48, and 72 hr. Samples were then preserved via one of four methods: sun dried, dried in the shade, vacumn dried, and frozen. Frozen samples produced lower organic acid levels after 72 hr of fermentation in both control (0.68 g/100 g) and yeast (0.61 g/100 g) applications than samples that were dried (0.94 g/100 g control samples; 0.81 g/100 g samples with yeast). Increasing fermentation time resulted in a significant effect on the formation of organic acid in the tarhana (p < .01). At 72 hr of fermentation, total acidity increased 11%, 17%, and 23% for tarhana samples vacumn-dried, sun-dried, and dried in the shade, respectively. Preservation methods also affected the moisture, ash, crude protein, total acidity, pH, salt, fat, reducing sugar levels, and the sensory assestment of tarhana soup (p < .01). Sensory characteristics were not significantly affected by baker's yeast in any of the preservation methods used (p > .01). However, sensory scores for tarhana prepared from the samples dried in a sheltered area showed a reduction in color desireablilty as the fermentation time increased. The soup prepared from frozen tarhana (72 hr fermentation, with yeast) had the highest scores with respect to color, mouth feel, flavor, and overall acceptability. Vacuum-dried samples' scores in these areas were also high in comparison to the two other drying methods. PMID:21108130

Gurbuz, Ozan; Gocmen, Duygu; Ozmen, Nese; Dagdelen, Fatih

2010-01-01

476

Aniline and its metabolites generate free radicals in yeast.  

PubMed

The carcinogen aniline is negative in the Ames Salmonella mutagenicity assay. Aniline does, however, induce intrachromosomal recombination between repeated sequences in Saccharomyces cerevisiae, resulting in deletion (DEL) of intervening sequences. We have investigated whether the generation of oxidative free radical species by aniline and/ or its metabolites may be responsible for its recombinagenic activity in yeast. The toxicity and recombinagenicity of aniline in yeast were greatly reduced in the presence of the free radical scavenger N-acetyl cysteine. Aniline cytotoxicity was many-fold increased in strains of S.cerevisiae lacking the antioxidant enzyme superoxide dismutase. Aniline also induced oxidation of the intracellular free radical-sensitive reporter compound 2,4-dichlorofluorescin diacetate to its fluorescent derivative 2,4-dichlorofluorescein in vivo in S.cerevisiae. The aniline metabolites 4-aminophenol and 2-aminophenol were significantly more potent inducers of DEL recombination in yeast than aniline. In contrast, the secondary metabolite 4-acetamidophenol (acetaminophen) was non-toxic and non-recombinagenic in yeast. 4-Aminophenol and 2-aminophenol were also significantly more toxic than aniline in a superoxide dismutase deficient yeast strain. 4-aminophenol was a significantly more potent oxidizer of 2,4-dichlorofluorescin diacetate than aniline. The Escherichia coli soxS promoter, which is induced in the presence of redox cycling agents like paraquat, was induced weakly by aniline at toxic doses. The soxS promoter was strongly induced by 4-aminophenol and 2-aminophenol. The results indicate a role for oxidative stress, mediated by generation of superoxide radical, in the toxicity and recombinagenicity of aniline. The increased activity of 4-aminophenol and 2-aminophenol suggests that ring hydroxylation may be an important activating step in this process. PMID:9237764

Brennan, R J; Schiestl, R H

1997-07-01

477

Storage of Brewing Yeasts by Liquid Nitrogen Refrigeration  

PubMed Central

Many yeast strains are difficult to maintain in culture in a stable state, and long-term preservation by lyophilization, which has proved useful for other fungi, has given poor results with brewing yeasts. As an alternative to continuous subculture, which maximizes strain variability, various methods of cryogenic storage were investigated. Yeast strains were frozen with or without cryoprotectants (such as glycerol or inositol) and stored at -196 C. Recovery after warming was estimated from plate counts, and survivors were screened to detect changes in the frequency of morphological types, respiratory-deficient mutants, and glycerol-sensitive mutants. Strains varied in their sensitivity to freezing, and survival was modified by the growth medium, the freezing munstrua, and the freezing conditions. Suspension of cells in 10% (vol/vol) glycerol, cooled at 1 C/min, warmed rapidly and plated on malt-yeast extract-glucose-peptone agar produced the highest percentage of viable colonies with a minimal change in metabolic characteristics. In two of the strains tested, no significant increase in mutation rate was detected under any of the treatments; the strains were maintained in a stable state and were metabolically comparable to unfrozen strains. In one strain of Saccharomyces uvarum after some freezing treatments, the percentage of respiratory-deficient mutants increased markedly, the fermentation rate declined, and a loss of flocculation occurred. The freezing parameters which increased the level of respiratory-deficient cells should be avoided in maintaining this strain. Maintenance of cultures of brewing yeasts by cryogenic storage has several advantages over other preservation techniques: the method is simple and reproducible, the cultures have remained stable over a 3-year test period, and the viability is high. PMID:16349973

Wellman, A. M.; Stewart, G. G.

1973-01-01

478

Chlorine dioxide against bacteria and yeasts from the alcoholic fermentation.  

PubMed

The ethanol production in Brazil is carried out by fed-batch or continuous process with cell recycle, in such way that bacterial contaminants are also recycled and may be troublesome due to the substrate competition. Addition of sulphuric acid when inoculum cells are washed can control the bacterial growth or alternatively biocides are used. This work aimed to verify the effect of chlorine dioxide, a well-known biocide for bacterial decontamination of water and equipments, against contaminant bacteria (Bacillus subtilis, Lactobacillus plantarum, Lactobacillus fermentum a