Application of airlift bioreactor for the cultivation of aerobic oleaginous yeast Rhodotorula glutinis with different aeration rates.

PubMed

Yen, Hong-Wei; Liu, Yi Xian

2014-08-01

The high cost of microbial oils produced from oleaginous microorganisms is the major obstacle to commercial production. In this study, the operation of an airlift bioreactor is examined for the cultivation of oleaginous yeast-Rhodotorula glutinis, due to the low process cost. The results suggest that the use of a high aeration rate could enhance cell growth. The maximum biomass concentration of 25.40 g/L was observed in the batch with a 2.0 vvm aeration rate. In addition, a higher aeration rate of 2.5 vvm could achieve the maximum growth rate of 0.46 g/L h, about twice the 0.22 g/L h obtained in an agitation tank. However, an increase in tank pressure instead of the aeration rate did not enhance cell growth. The operation of airlift bioreactor described in this work has the advantages of simple operation and low energy consumption, thus making it suitable for the accumulation of microbial oils. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Optimization of oligomeric enzyme activity in ionic liquids using Rhodotorula glutinis yeast phenylalanine ammonia lyase.

PubMed

Barron, Christiaan C; Sponagle, Brandon J D; Arivalagan, Pugazhendhi; D'Cunha, Godwin B

2017-01-01

Phenylalanine ammonia lyase (E.C.4.3.1.24, PAL) activity of Rhodotorula glutinis yeast has been demonstrated in four commonly used ionic liquids. PAL forward reaction was carried out in 1-butyl-3-methylimidazolium methyl sulfate ([BMIM][MeSO 4 ]), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF 4 ]), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF 6 ]) and 1-butyl-3-methylimidazolium lactate ([BMIM][lactate]). Our experiments have revealed that PAL is catalytically active in ionic liquids and the enzyme activity in ([BMIM][PF 6 ]) is comparable to that obtained in aqueous buffer medium. Different conditions were optimized for maximal PAL forward activity including time of incubation (30.0min) L -phenylalanine substrate concentration (30.0mM), nature of buffer (50.0mM Tris-HCl), pH (9.0), temperature (37°C), and speed of agitation (100 rev min -1 ). Under these optimized conditions, about 83% conversion of substrate to product was obtained for the PAL forward reaction that was determined using UV spectroscopy at 290nm. PAL reverse reaction in ([BMIM][PF 6 ]) was determined spectrophotometrically at 520nm; and about 59% substrate conversion was obtained. This data provides further knowledge in enzyme biocatalysis in non-aqueous media, and may be of importance when studying the function of other oligomeric/multimeric proteins and enzymes in ionic liquids. Copyright © 2016 Elsevier Inc. All rights reserved.

Utilization of Exocellular Mannan from Rhodotorula glutinis as an Immunoreactive Antigen in Diagnosis of Leptospirosis

PubMed Central

Matsuo, Kouki; Isogai, Emiko; Araki, Yoshio

2000-01-01

Previously, Rhodotorula glutinis was reported to produce a large amount of exocellular mannan, having a repeating unit of →3)-d-Manp-(1→4)-d-Manp-(1→. Recently, we found that antigenic polysaccharides of Leptospira biflexa serovar patoc strain Patoc I have the same repeating unit and cross-react with antisera raised against extended strains of other leptospires (K. Matsuo, E. Isogai, and Y. Araki, Carbohydr. Res., in press). This structural identity and the difficulty of producing and isolating antigens led us to confirm the usefulness of Rhodotorula mannan as an immunoreactive antigen in a serological diagnosis of leptospirosis. In the present investigation, we confirmed the structural identity of an exocellular mannan isolated from R. glutinis AHU 3479 and tried to use it as an immunoreactive antigen in a serological diagnosis of leptospirosis. From its chemical analysis and 1H- and 13C-labeled nuclear magnetic resonance spectrometry, the Rhodotorula mannan was confirmed to consist of the same disaccharide units. Furthermore, such a preparation was shown to immunoreact to various sera from patients suffering with leptospirosis as well as to most rabbit antiserum preparations obtained from immunization with various strains of pathogenic leptospires. Therefore, the Rhodotorula mannan preparation is useful as an immunoreactive antigen in the serological diagnosis for leptospirosis. PMID:11015396

Systematic development of a two-stage fed-batch process for lipid accumulation in Rhodotorula glutinis.

PubMed

Lorenz, Eric; Runge, Dennis; Marbà-Ardébol, Anna-Maria; Schmacht, Maximilian; Stahl, Ulf; Senz, Martin

2017-03-20

The application of oleaginous yeast cells as feed supplement, for instance in aqua culture, can be a meaningful alternative for fish meal and oil additives. Therefore, a two-stage fed-batch process split into growth and lipogenesis phase was systematically developed to enrich the oleaginous yeast Rhodotorula glutinis Rh-00301 with high amounts of lipids at industrial relevant biomasses. Thereby, the different carbon sources glucose, sucrose and glycerol were investigated concerning their abilities to serve as a suited raw material for growth and/or lipid accumulation. With the background of economic efficiency C/N ratios of 40, 50 and 70 were investigated as well. It became apparent that glycerol is an improper carbon source most likely because of the passive diffusion of this compound caused by absence of active transporters. The opposite was observed for sucrose, which is the main carbon source in molasses. Finally, an industrially applicable process was successfully established that ensures biomasses of 106±2gL -1 combined with an attractive lipid content of 63±6% and a high lipid-substrate yield (Y L/S ) of 0.18±0.02gg -1 in a short period of time (84h). Furthermore, during these studies a non-negligible formation of the by-product glycerol was detected. This characteristic of R. glutinis is discussed related to other oleaginous yeasts, where glycerol formation is absent. Nevertheless, due to modifications in the feeding procedure, the formation of glycerol could have been reduced but not avoided. Copyright © 2017 Elsevier B.V. All rights reserved.

Co-production of tannase and pectinase by free and immobilized cells of the yeast Rhodotorula glutinis MP-10 isolated from tannin-rich persimmon (Diospyros kaki L.) fruits.

PubMed

Taskin, Mesut

2013-02-01

Hyper tannase and pectinase-producing yeast Rhodotorula glutinis MP-10 was isolated from persimmon (Diospyros kaki L.) fruits. The main pectinase activity of yeast was exo-polygalacturonase. No pectin methyl esterase and too low pectin lyase activities were detected for this yeast. The maximum exo-activities of tannase and polygalacturonase were determined as 15.2 and 26.9 U/mL for free cells and 19.8 and 28.6 U/mL for immobilized cells, respectively. Immobilized cells could be reused in 13 successive reaction cycles without any loss in the maximum tannase and polygalacturonase activities. Besides, too little decreases in activities of these enzymes were recorded between 14 and 18 cycles. At the end of 18 successive reaction cycles, total 503.1 U/mL of polygalacturonase and 349.6 U/mL of tannase could be produced using the same immobilized cells. This is the first report on the use of free and/or immobilized cells of a microorganism for the co-production of tannase and pectinase.

From crude glycerol to carotenoids by using a Rhodotorula glutinis mutant.

PubMed

Cutzu, Raffaela; Coi, Annalisa; Rosso, Fulvia; Bardi, Laura; Ciani, Maurizio; Budroni, Marilena; Zara, Giacomo; Zara, Severino; Mannazzu, Ilaria

2013-06-01

In this work eighteen red yeasts were screened for carotenoids production on glycerol containing medium. Strain C2.5t1 of Rhodotorula glutinis, that showed the highest productivity, was UV mutagenized. Mutant 400A15, that exhibited a 280 % increase in β-carotene production in respect to the parental strain, was selected. A central composite design was applied to 400A15 to optimize carotenoids and biomass productions. Regression analyses of the quadratic polynomial equations obtained (R(2) = 0.87 and 0.94, for carotenoids and biomass, respectively) suggest that the models are reliable and significant (P < 0.0001) in the prediction of carotenoids and biomass productions on the basis of the concentrations of crude glycerol, yeast extract and peptone. Accordingly, total carotenoids production achieved (14.07 ± 1.45 mg l(-1)) under optimized growth conditions was not statistically different from the maximal predicted (14.64 ± 1.57 mg l(-1)) (P < 0.05), and it was about 100 % higher than that obtained under un-optimized conditions. Therefore mutant 400A15 may represent a biocatalyst of choice for the bioconversion of crude glycerol into value-added metabolites, and a tool for the valorization of this by-product of the biodiesel industry.

Growth of oleaginous Rhodotorula glutinis in an internal-loop airlift bioreactor by using lignocellulosic biomass hydrolysate as the carbon source.

PubMed

Yen, Hong-Wei; Chang, Jung-Tzu

2015-05-01

The conversion of abundant lignocellulosic biomass (LCB) to valuable compounds has become a very attractive idea recently. This study successfully used LCB (rice straw) hydrolysate as a carbon source for the cultivation of oleaginous yeast-Rhodotorula glutinis in an airlift bioreactor. The lipid content of 34.3 ± 0.6% was obtained in an airlift batch with 60 g reducing sugars/L of LCB hydrolysate at a 2 vvm aeration rate. While using LCB hydrolysate as the carbon source, oleic acid (C18:1) and linoleic acid (C18:2) were the predominant fatty acids of the microbial lipids. Using LCB hydrolysate in the airlift bioreactor at 2 vvm achieved the highest cell mass growth as compared to the agitation tank. Despite the low lipid content of the batch using LCB hydrolysate, this low cost feedstock has the potential of being adopted for the production of β-carotene instead of lipid accumulation in the airlift bioreactor for the cultivation of R. glutinis. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Parameters and kinetics of olive mill wastewater dephenolization by immobilized Rhodotorula glutinis cells.

PubMed

Bozkoyunlu, Gaye; Takaç, Serpil

2014-01-01

Olive mill wastewater (OMW) with total phenol (TP) concentration range of 300-1200 mg/L was treated with alginate-immobilized Rhodotorula glutinis cells in batch system. The effects of pellet properties (diameter, alginate concentration and cell loading (CL)) and operational parameters (initial TP concentration, agitation rate and reusability of pellets) on dephenolization of OMW were studied. Up to 87% dephenolization was obtained after 120 h biodegradations. The utilization number of pellets increased with the addition of calcium ions into the biodegradation medium. The overall effectiveness factors calculated for different conditions showed that diffusional limitations arising from pellet size and pellet composition could be neglected. Mass transfer limitations appeared to be more effective at high substrate concentrations and low agitation rates. The parameters of logistic model for growth kinetics of R. glutinis in OMW were estimated at different initial phenol concentrations of OMW by curve-fitting of experimental data with the model.

Enhanced lipid production with undetoxified corncob hydrolysate by Rhodotorula glutinis using a high cell density culture strategy.

PubMed

Liu, Yating; Wang, Yanping; Liu, Hongjuan; Zhang, Jian'an

2015-03-01

In recent years, energy crisis and environmental issues such as greenhouse effect, global warming, etc. has roused peoples' concern. Biodiesel, as renewable energy, has attracted much attention to deal with such problems. This work studied the lipid production by Rhodotorula glutinis with undetoxified corncob hydrolysate. The results indicated that R. glutinis had high tolerance to the inhibitors in corncob hydrolysate and it could utilize undetoxified corncob hydrolysate directly for lipid production. The cell grew well with undetoxified hydrolysate in the batch culture of 5L fermentor with the optimized C/N ratio of 75, lipid titer and lipid content reached 5.5g/L and 36.4%, respectively. High cell density culture with two-stage nitrogen feeding strategy was studied to enhance the lipid production, biomass, lipid concentration and lipid content of 70.8, 33.5g/L and 47.2% were obtained. The results indicated the potential application for lipid production by R. glutinis with corncob hydrolysate directly. Copyright © 2014 Elsevier Ltd. All rights reserved.

Rhodotorula bloemfonteinensis sp. nov., Rhodotorula eucalyptica sp. nov., Rhodotorula orientis sp. nov. and Rhodotorula pini sp. nov., yeasts isolated from monoterpene-rich environments.

PubMed

Pohl, Carolina H; Smit, Martha S; Albertyn, Jacobus

2011-09-01

Recent rDNA sequencing of 25 isolates from a previous study, during which limonene-utilizing yeasts were isolated from monoterpene-rich environments by using 1,4-disubstituted cyclohexanes as sole carbon sources, led to the identification of four hitherto unknown Rhodotorula species. Analyses of the 26S rDNA D1/D2 region as well as the internal transcribed spacer (ITS) domain indicated that two isolates (CBS 8499(T) and CBS 10736) were identical and were closely related to Rhodotorula cycloclastica, a previously described limonene-utilizing yeast. These novel isolates differed from known yeast species and could be distinguished from R. cycloclastica by standard physiological tests. The other three isolates represent three novel Rhodotorula species, closely related to Sporobolomyces magnisporus. These three species could also be distinguished from other Rhodotorula species by standard physiological tests. Based on these results, we suggest that the new isolates represent novel species, for which the names Rhodotorula eucalyptica sp. nov. (type strain CBS 8499(T)  = NRRL Y-48408(T)), Rhodotorula pini sp. nov. (type strain CBS 10735(T)  = NRRL Y-48410(T)), Rhodotorula bloemfonteinensis sp. nov. (type strain CBS 8598(T)  = NRRL Y-48407(T)) and Rhodotorula orientis sp. nov. (type strain CBS 8594(T)  = NRRL Y-48719(T)) are proposed. R. eucalyptica and R. pini can also utilize limonene.

Production of beta-carotene by a Rhodotorula glutinis mutant in sea water medium.

PubMed

Bhosale, P; Gadre, R V

2001-01-01

Mutant 32, derived from Rhodotorula glutinis NCIM 3353 produced 76-fold more beta-carotene than the parent strain. In the growth medium prepared in seawater, the total carotenoid content and dry cell mass was 86 mg/l and 16 g/l, respectively, as compared to 70 mg/l and 12 g/l obtained with a medium prepared in distilled water. A 2-fold increase in beta-carotene with simultaneous 2.3-fold decrease in torulene content was also observed. When grown in seawater medium at pH 6.0, 83 +/- 5% carotenoids could be extracted from the cells without any mechanical disintegration.

Correlation of polyunsaturated fatty acids with the cold adaptation of Rhodotorula glutinis.

PubMed

He, Jing; Yang, Zhaojie; Hu, Binbin; Ji, Xiuling; Wei, Yunlin; Lin, Lianbing; Zhang, Qi

2015-11-01

This study aimed to investigate the correlation between the cold adaptation of Rhodotorula glutinis YM25079 and the membrane fluidity, content of polyunsaturated fatty acids and mRNA expression level of the Δ(12)-desaturase gene. The optimum temperature for YM25079 growth was analysed first, then the composition changes of membrane lipid in YM25079 were detected by GC-MS and membrane fluidity was evaluated by 1-anilinonaphthalene-8-sulphonate (ANS) fluorescence. Meanwhile, the encoding sequence of Δ(12)-fatty acid desaturase in YM25079 was cloned and further transformed into Saccharomyces cerevisiae INVScl for functional analysis. The mRNA expression levels of Δ(12)-fatty acid desaturase at 15°C and 25°C were analysed by real-time PCR. YM25079 could grow at 5-30°C, with the optimum temperature of 15°C. The membrane fluidity of YM25079 was not significantly reduced when the culture temperature decreased from 25°C to 15°C, but the content of polyunsaturated fatty acids (PUFAs), including linoleic acid and α-Linolenic acid increased significantly from 29.4% to 55.39%. Furthermore, a novel Δ(12)-fatty acid desaturase gene YM25079RGD12 from YM25079 was successfully identified and characterized, and the mRNA transcription level of the Δ(12)-desaturase gene was about five-fold higher in YM25079 cells grown at 15°C than that at 25°C. These results suggests that the cold adaptation of Rhodotorula glutinis YM25079 might result from higher expression of genes, especially the Δ(12)-fatty acid desaturase gene, during polyunsaturated fatty acids biosynthesis, which increased the content of PUFAs in the cell membrane and maintained the membrane fluidity at low temperature. Copyright © 2015 John Wiley & Sons, Ltd.

Oleaginous yeasts from Antarctica: Screening and preliminary approach on lipid accumulation.

PubMed

Viñarta, Silvana C; Angelicola, M Virginia; Barros, J Maximiliano; Fernández, Pablo M; Mac Cormak, Walter; Aybar, Manuel J; de Figueroa, Lucía I C

2016-12-01

The capability of 17 Rhodotorula spp. isolated from Antarctica to accumulate intracellular lipids in nitrogen-limited medium was investigated. As results, 10 isolates were selected by Nile red staining, while 12 isolates were selected as oleaginous by analysis of total lipid content (20.4-73%, w/w of dry biomass). The higher lipid production and accumulation was exhibited for six strains belonging to three species of Rhodotorula (Rhodotorula glutinis, Rhodotorula glacialis, and Rhodotorula laryngis). This is the first report where R. laryngis have been identified within oleaginous specie. Lipid accumulation was evaluated comparatively in two nitrogen-limited glucose-based media (MI and MII). MI (low C/N ratio) was more suitable for biomass and lipid production while in MII (high C/N ratio) total lipid content was improved. R. glutinis R4, R. glacialis R15, and R. glutinis R48 showed high lipid concentrations (4.65-6.93 g L -1 ) and they were able to accumulate large amounts of lipids per gram of biomass (47-77%, w/w). A similar profile in fatty acids composition and content of neutral lipids to vegetable oils was observed, indicating that lipids produced by oleaginous Antarctic yeasts can be considered an alternative feedstock for biodiesel production. Antarctica represents an important source of oleaginous yeasts with adaptive capabilities to accumulate considerable amounts of lipids with biotechnological interest at 15 °C and 25 °C. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Epidemiology of Rhodotorula: An Emerging Pathogen

PubMed Central

Wirth, Fernanda; Goldani, Luciano Z.

2012-01-01

This is an updated paper focusing on the general epidemiological aspects of Rhodotorula in humans, animals, and the environment. Previously considered nonpathogenic, Rhodotorula species have emerged as opportunistic pathogens that have the ability to colonise and infect susceptible patients. Rhodotorula species are ubiquitous saprophytic yeasts that can be recovered from many environmental sources. Several authors describe the isolation of this fungus from different ecosystems, including sites with unfavourable conditions. Compared to R. mucilaginosa, R. glutinis and R. minuta are less frequently isolated from natural environments. Among the few references to the pathogenicity of Rhodotorula spp. in animals, there are several reports of an outbreak of skin infections in chickens and sea animals and lung infections and otitis in sheep and cattle. Most of the cases of infection due to Rhodotorula in humans were fungemia associated with central venous catheter (CVC) use. The most common underlying diseases included solid and haematologic malignancies in patients who were receiving corticosteroids and cytotoxic drugs, the presence of CVC, and the use of broad-spectrum antibiotics. Unlike fungemia, some of the other localised infections caused by Rhodotorula, including meningeal, skin, ocular, peritoneal, and prosthetic joint infections, are not necessarily linked to the use of CVCs or immunosuppression. PMID:23091485

High Rhodotorula sequences in skin transcriptome of patients with diffuse systemic sclerosis

PubMed Central

Arron, Sarah T.; Dimon, Michelle T.; Li, Zhenghui; Johnson, Michael E.; Wood, Tammara; Feeney, Luzviminda; Angeles, Jorge Gil; Lafyatis, Robert; Whitfield, Michael L.

2014-01-01

Previous studies have suggested a role for pathogens as a trigger of systemic sclerosis (SSc), though neither a pathogen nor a mechanism of pathogenesis is known. Here we show enrichment of Rhodotorula sequences in the skin of patients with early, diffuse SSc compared to normal controls. RNA-seq was performed on four SSc and four controls, to a depth of 200 million reads per patient. Data were analyzed to quantify the non-human sequence reads in each sample. We found little difference between bacterial microbiome and viral read counts, but found a significant difference between the read counts for a mycobiome component, R. glutinis. Normal samples contained almost no detected R. glutinis or other Rhodotorula sequence reads (mean score 0.021 for R. glutinis, 0.024 for all Rhodotorula). In contrast, SSc samples had a mean score of 5.039 for R. glutinis (5.232 for Rhodotorula). We were able to assemble the D1–D2 hypervariable region of the 28S rRNA of R. glutinis from each of the SSc samples. Taken together, these results suggest R. glutinis may be present in the skin of early SSc patients at higher levels than normal skin, raising the possibility that it may be triggering the inflammatory response found in SSc. PMID:24608988

Assessment of β-carotene content, cell physiology and morphology of the yellow yeast Rhodotorula glutinis mutant 400A15 using flow cytometry.

PubMed

Cutzu, Raffaela; Clemente, Ana; Reis, Alberto; Nobre, Beatriz; Mannazzu, Ilaria; Roseiro, José; Lopes da Silva, Teresa

2013-08-01

Flow cytometry was used to assess β-carotene content, cell membrane permeability, cell size and granularity in Rhodotorula glutinis mutant 400A15 grown under different oxygen transfer coefficients (k L a) and carbon to nitrogen ratios (C/N). A Doehlert distribution was used in order to select the best conditions that induced the highest carotenoids production. The highest β-carotene content (0.79 mg g(-1) DCW) at the lowest k L a and C/N (5 × 10(-3) s(-1) and 11.3 respectively). Under these conditions, the biomass concentration attained 18.60 g L(-1). The highest ratio of cells with permeabilised membranes (2.6 %), and the highest cell size and granularity were also obtained under these conditions. It was observed that C/N showed a stronger influence than the k L a on the measured cell parameters.

High Rhodotorula sequences in skin transcriptome of patients with diffuse systemic sclerosis.

PubMed

Arron, Sarah T; Dimon, Michelle T; Li, Zhenghui; Johnson, Michael E; Wood, Tammara A; Feeney, Luzviminda; Angeles, Jorge G; Lafyatis, Robert; Whitfield, Michael L

2014-08-01

Previous studies have suggested a role for pathogens as a trigger of systemic sclerosis (SSc), although neither a pathogen nor a mechanism of pathogenesis is known. Here we show enrichment of Rhodotorula sequences in the skin of patients with early, diffuse SSc compared with that in normal controls. RNA-seq was performed on four SSc patients and four controls, to a depth of 200 million reads per patient. Data were analyzed to quantify the nonhuman sequence reads in each sample. We found little difference between bacterial microbiome and viral read counts, but found a significant difference between the read counts for a mycobiome component, R. glutinis. Normal samples contained almost no detected R. glutinis or other Rhodotorula sequence reads (mean score 0.021 for R. glutinis, 0.024 for all Rhodotorula). In contrast, SSc samples had a mean score of 5.039 for R. glutinis (5.232 for Rhodotorula). We were able to assemble the D1-D2 hypervariable region of the 28S ribosomal RNA (rRNA) of R. glutinis from each of the SSc samples. Taken together, these results suggest that R. glutinis may be present in the skin of early SSc patients at higher levels than in normal skin, raising the possibility that it may be triggering the inflammatory response found in SSc.

Some biological activities of pigments extracted from Micrococcus roseus (PTCC 1411) and Rhodotorula glutinis (PTCC 5257).

PubMed

Rostami, Hossein; Hamedi, Hassan; Yolmeh, Mahmoud

2016-12-01

The importance of replacing synthetic pigments with natural types is increasing day by day in the food industry due to the harmful effects of some synthetic pigments. Microorganisms are a major source of natural pigments, which nowadays have attracted the attention of researchers. In this study, carotenoid pigments were produced by Micrococcus roseus and Rhodotorula glutinis, and some of their biological properties such as antimicrobial, antioxidant, anticancer, and anti-inflammatory activities were evaluated. Given the results, bacteria, especially gram-positive bacteria, had higher sensitivity to the pigments extracted from M. roseus (PEM) and R. glutinis (PER) compared to molds so that Bacillus cereus and Alternaria citri had the highest and the lowest sensitivity, respectively. PER showed a higher antioxidant activity compared with PEM in the various methods of measuring antioxidant activity. In vitro and in vivo anti-tumor-promoting activities of PER were measured significantly more than PEM (P <0.05). Both pigment extracts remarkably inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, so that ID 50 (50% inhibitory dose) of PEM and PER were 0.22 and 0.09 mg/ear, respectively. © The Author(s) 2016.

Some biological activities of pigments extracted from Micrococcus roseus (PTCC 1411) and Rhodotorula glutinis (PTCC 5257)

PubMed Central

Rostami, Hossein; Hamedi, Hassan; Yolmeh, Mahmoud

2016-01-01

The importance of replacing synthetic pigments with natural types is increasing day by day in the food industry due to the harmful effects of some synthetic pigments. Microorganisms are a major source of natural pigments, which nowadays have attracted the attention of researchers. In this study, carotenoid pigments were produced by Micrococcus roseus and Rhodotorula glutinis, and some of their biological properties such as antimicrobial, antioxidant, anticancer, and anti-inflammatory activities were evaluated. Given the results, bacteria, especially gram-positive bacteria, had higher sensitivity to the pigments extracted from M. roseus (PEM) and R. glutinis (PER) compared to molds so that Bacillus cereus and Alternaria citri had the highest and the lowest sensitivity, respectively. PER showed a higher antioxidant activity compared with PEM in the various methods of measuring antioxidant activity. In vitro and in vivo anti-tumor-promoting activities of PER were measured significantly more than PEM (P <0.05). Both pigment extracts remarkably inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, so that ID50 (50% inhibitory dose) of PEM and PER were 0.22 and 0.09 mg/ear, respectively. PMID:27895288

Pyrene degradation by yeasts and filamentous fungi.

PubMed

Romero, M Cristina; Salvioli, Mónica L; Cazau, M Cecilia; Arambarri, A M

2002-01-01

The saprotrophic soil fungi Fusarium solani (Mart.) Sacc., Cylindrocarpon didymum (Hartig) Wollenw, Penicillium variabile Sopp. and the yeasts Rhodotorula glutinis (Fresenius) Harrison and Rhodotorula minuta (Saito) Harrison were cultured in mineral medium with pyrene. The remaining pyrene concentrations were periodically determined during 20 incubation days, using HPLC. To assess the metabolism of pyrene degradation we added 0.1 microCi of [4,5,9,10] 14C-pyrene to each fungi culture and measured the radioactivity in the volatile organic substances, extractable, aqueous phase, biomass and 14CO2 fractions. The assays demonstrated that F. solani and R. glutinis metabolized pyrene as a sole source of carbon. Differences in their activities at the beginning of the cultures disappeared by the end of the experiment, when 32 and 37% of the original pyrene concentration was detected, for the soil fungi and yeasts, respectively. Among the filamentous fungi, F. solani was highly active and oxidized pyrene; moreover, small but significant degradation rates were observed in C. didymum and P. variahile cultures. An increase in the 14CO2 evolution was observed at the 17th day with cosubstrate. R. glutinis and R. minuta cultures showed similar ability to biotransform pyrene, and that 35% of the initial concentration was consumed at the end of the assay. The same results were obtained in the experiments with or without glucose as cosubstrate.

Role of L-lysine-alpha-ketoglutarate aminotransferase in catabolism of lysine as a nitrogen source for Rhodotorula glutinis.

PubMed Central

Kinzel, J J; Winston, M K; Bhattacharjee, J K

1983-01-01

Wild-type and saccharopine dehydrogenaseless mutant strains of Rhodotorula glutinis grew in minimal medium containing lysine as the sole nitrogen source and simultaneously accumulated, in the culture supernatant, large amounts of a product identified as alpha-aminoadipic-delta-semialdehyde. The saccharopine dehydrogenase and pipecolic acid oxidase levels remained unchanged in wild-type cells grown in the presence of ammonium or lysine as the nitrogen source. Lysine-alpha-ketoglutarate aminotransferase activity was demonstrated in ammonium-grown cells. This activity was depressed in cells grown in the presence of lysine as the sole source of nitrogen. PMID:6408065

The effect of amino acids on lipid production and nutrient removal by Rhodotorula glutinis cultivation in starch wastewater.

PubMed

Liu, Meng; Zhang, Xu; Tan, Tianwei

2016-10-01

In this paper, the components of amino acids in mixed starch wastewater (corn steep water/corn gluten water=1/3, v/v) were analyzed by GC-MS. Effects of amino acids on lipid production by Rhodotorula glutinis and COD removal were studied. The results showed that mixed starch wastewater contained 9 kinds of amino acids and these amino acids significantly improved the biomass (13.63g/L), lipid yield (2.48g/L) and COD removal compared to the basic medium (6.23g/L and 1.56g/L). In a 5L fermentor containing mixed starch wastewater as substrate to culture R. glutinis, the maximum biomass, lipid content and lipid yield reached 26.38g/L, 28.90% and 7.62g/L, with the associated removal rates of COD, TN and TP reaching 77.41%, 69.12% and 73.85%, respectively. The results revealed a promising approach for lipid production with using amino acids present in starch wastewater as an alternative nitrogen source. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improved stereoselective bioreduction of t-butyl 6-cyano-(5R)-hydroxy-3-oxohexanoate by Rhodotorula glutinis through heat treatment.

PubMed

Luo, Xi; Wang, Ya-Jun; Zheng, Yu-Guo

2016-11-01

Optically pure t-butyl 6-cyano-(3R, 5R)-dihydroxyhexanoate ((R)-1b) is the key precursor for atorvastatin calcium, the most widely used cholesterol-lowering drug. In this work, a strain ZJB-09224 capable of asymmetrically reducing t-butyl 6-cyano-(5R)-hydroxy-3-oxohexanoate (1a) to corresponding optically pure (R)-1b was successfully isolated from soil sample, identified belonging to Rhodotorula glutinis based on the morphology, physiological tests, and the 18S rDNA sequence analysis. It was found that heat treatment of cell suspension at 45 °C for 25 Min significantly improved R. glutinis ZJB-09224 stereoselectivity. The asymmetric bioreduction of 1a was most efficient at pH 7.5, 35 °C, 50 mM (15.0 g L -1 ) substrate concentration, 40.0 g DCW L -1 cell loading size, 0.54 M (60.0 g L -1 ) sodium lactate acting as co-substrate. Under these optimal conditions, 0.046 M (R)-1b was produced with de (diastereomeric excess) value of 99.2% after 40 H conversion. Moreover, R. glutinis ZJB-09224 has a broad substrate spectrum, making it a potential tool for some valuable chiral alcohol pharmaceutical intermediates synthesis. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

Investigation of the simultaneous production of superoxide dismutase and catalase enzymes from Rhodotorula glutinis under different culture conditions.

PubMed

Unlü, Ayşe Ezgi; Takaç, Serpil

2012-10-01

The simultaneous production production of superoxide (SOD) and catalase (CAT) from Rhodotorula glutinis was studied. The effects of temperature, initial medium pH, and carbon source on the enzyme activities were investigated. Temperature and carbon sources were found to have significant effects on the enzyme activities. 10°C provided the highest specific CAT and SOD activities as 22.6 U/mg protein and 170 U/mg protein, respectively. Glycerol was found to be the best carbon source for enzyme activities, providing 113 U/mg protein for CAT and 125 U/mg protein for SOD, which were also the highest activities obtained in the present study.

Enhanced single cell oil production by mixed culture of Chlorella pyrenoidosa and Rhodotorula glutinis using cassava bagasse hydrolysate as carbon source.

PubMed

Liu, Lu; Chen, Junhui; Lim, Phaik-Eem; Wei, Dong

2018-05-01

The single cell oil (SCO) production by the mono and mixed culture of microalgae Chlorella pyrenoidosa and red yeast Rhodotorula glutinis was investigated using non-detoxified cassava bagasse hydrolysate (CBH) as carbon source. The results suggested that the two strains were able to tolerate and even degrade some byproducts presented in the CBH, and the mixed culture approach enhanced the degradation of certain byproducts. Biomass (20.37 ± 0.38 g/L) and lipid yield (10.42 ± 1.21 g/L) of the mixed culture achieved in the batch culture were significantly higher than that of the mono-cultures (p < 0.05). The fed-batch culture further raised the biomass and lipid yield to 31.45 ± 4.93 g/L and 18.47 ± 3.25 g/L, respectively. The lipids mainly composed of oleic acid and palmitic acid, suggesting the potential applications such as biofuel feedstock, cosmetics, food additives and lubricant. This study provided new insights for the integration of the economical SCO production with agro-industrial waste disposal. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of tung oilseed FAD2 and DGAT2 genes on unsaturated fatty acid accumulation in Rhodotorula glutinis and Arabidopsis thaliana.

PubMed

Chen, Yicun; Cui, Qinqin; Xu, Yongjie; Yang, Susu; Gao, Ming; Wang, Yangdong

2015-08-01

Genetic engineering to produce valuable lipids containing unsaturated fatty acids (UFAs) holds great promise for food and industrial applications. Efforts to genetically modify plants to produce desirable UFAs with single enzymes, however, have had modest success. The key enzymes fatty acid desaturase (FAD) and diacylglycerol acyltransferase (DGAT) are responsible for UFA biosynthesis (a push process) and assembling fatty acids into lipids (a pull process) in plants, respectively. To examine their roles in UFA accumulation, VfFAD2 and VfDGAT2 genes cloned from Vernicia fordii (tung tree) oilseeds were conjugated and transformed into Rhodotorula glutinis and Arabidopsis thaliana via Agrobacterium tumefaciens. Real-time quantitative PCR revealed variable gene expression levels in the transformants, with a much higher level of VfDGAT2 than VfFAD2. The relationship between VfFAD2 expression and linoleic acid (C18:2) increases in R. glutinis (R (2) = 0.98) and A. thaliana (R (2) = 0.857) transformants was statistically linear. The VfDGAT2 expression level was statistically correlated with increased total fatty acid content in R. glutinis (R (2) = 0.962) and A. thaliana (R (2) = 0.8157) transformants. With a similar expression level between single- and two-gene transformants, VfFAD2-VfDGAT2 co-transformants showed a higher linolenic acid (C18:3) yield in R. glutinis (174.36 % increase) and A. thaliana (14.61 % increase), and eicosatrienoic acid (C20:3) was enriched (17.10 % increase) in A. thaliana. Our data suggest that VfFAD2-VfDGAT2 had a synergistic effect on UFA metabolism in R. glutinis, and to a lesser extent, A. thaliana. These results show promise for further genetic engineering of plant lipids to produce desirable UFAs.

Modeling of process parameters for enhanced production of coenzyme Q10 from Rhodotorula glutinis.

PubMed

Balakumaran, Palanisamy Athiyaman; Meenakshisundaram, Sankaranarayanan

2015-01-01

Coenzyme Q10 (CoQ10) plays an indispensable role in ATP generation through oxidative phosphorylation and helps in scavenging superoxides generated during electron transfer reactions. It finds extensive applications specifically related to oxidative damage and metabolic dysfunctions. This article reports the use of a statistical approach to optimize the concentration of key variables for the enhanced production of CoQ10 by Rhodotorula glutinis in a lab-scale fermenter. The culture conditions that promote optimum growth and CoQ10 production were optimized and the interaction of significant variables para-hydroxybenzoic acid (PHB, 819.34 mg/L) and soybean oil (7.78% [v/v]) was studied using response surface methodology (RSM). CoQ10 production increased considerably from 10 mg/L (in control) to 39.2 mg/L in batch mode with RSM-optimized precursor concentration. In the fed-batch mode, PHB and soybean oil feeding strategy enhanced CoQ10 production to 78.2 mg/L.

Rhodotorula portillonensis sp. nov., a basidiomycetous yeast isolated from Antarctic shallow-water marine sediment.

PubMed

Laich, Federico; Vaca, Inmaculada; Chávez, Renato

2013-10-01

During the characterization of the mycobiota associated with shallow-water marine environments from Antarctic sea, a novel pink yeast species was isolated. Sequence analysis of the D1/D2 domain of the LSU rDNA gene and 5.8S-ITS regions revealed that the isolated yeast was closely related to Rhodotorula pallida CBS 320(T) and Rhodotorula benthica CBS 9124(T). On the basis of morphological, biochemical and physiological characterization and phylogenetic analyses, a novel basidiomycetous yeast species, Rhodotorula portillonensis sp. nov., is proposed. The type strain is Pi2(T) ( = CBS 12733(T)  = CECT 13081(T)) which was isolated from shallow-water marine sediment in Fildes Bay, King George Island, Antarctica.

Stabilization of Phenylalanine Ammonia Lyase from Rhodotorula glutinis by Encapsulation in Polyethyleneimine-Mediated Biomimetic Silica.

PubMed

Cui, Jiandong; Liang, Longhao; Han, Cong; Lin Liu, Rong

2015-06-01

Phenylalanine ammonia lyase (PAL) from Rhodotorula glutinis was encapsulated within polyethyleneimine-mediated biomimetic silica. The main factors in the preparation of biomimetic silica were optimized by response surface methodology (RSM). Compared to free PAL (about 2 U), the encapsulated PAL retained more than 43 % of their initial activity after 1 h of incubation time at 60 °C, whereas free PAL lost most of activity in the same conditions. It was clearly indicated that the thermal stability of PAL was improved by encapsulation. Moreover, the encapsulated PAL exhibited the excellent stability of the enzyme against denaturants and storage stability, and pH stability was improved by encapsulation. Operational stability of 7 reaction cycles showed that the encapsulated PAL was stable. Nevertheless, the K m value of encapsulated PAL in biomimetic silica was higher than that of the free PAL due to lower total surface area and increased mass transfer resistance.

Cystobasidiomycetes yeasts from Patagonia (Argentina): description of Rhodotorula meli sp. nov. from glacial meltwater.

PubMed

Libkind, Diego; Sampaio, José Paulo; van Broock, Maria

2010-09-01

A basidiomycetous yeast, strain CRUB 1032(T), which formed salmon-pink colonies, was isolated from glacial meltwater in Patagonia, Argentina. Morphological, physiological and biochemical characterization indicated that this strain belonged to the genus Rhodotorula. Molecular taxonomic analysis based on the 26S rDNA D1/D2 domain and internal transcribed spacer region sequences showed that strain CRUB 1032(T) represents an undescribed yeast species, for which the name Rhodotorula meli sp. nov. is proposed (type strain is CRUB 1032(T)=CBS 10797(T)=JCM 15319(T)). Phylogenetic analysis showed that Rhodotorula lamellibrachii was the closest known species, which, together with R. meli, formed a separate cluster related to the Sakaguchia clade within the Cystobasidiomycetes. Additional Patagonian yeast isolates of the class Cystobasidiomycetes are also investigated in the present work.

Occurrence of yeasts in psittacines droppings from captive birds in Italy.

PubMed

Mancianti, Francesca; Nardoni, Simona; Ceccherelli, Renato

2002-01-01

Three-hundred twenty five droppings from parrots raised in the premises of 4 breeders and in several private households were cultured for yeasts. One-hundred sixty droppings (49.2%) resulted positive. From these specimens 212 isolates belonging to 27 different species were obtained. Mainly Candida species such as C. albicans, C. catenulata, C. curvata, C. famata, C. glabrata, C. guilliermondi, C. holmii, C. intermedia, C. krusei, C. lambica, C. lusitaniae, C. membranaefaciens, C. parapsilosis, C. pelliculosa, C. sake and C. valida were isolated. Debarvomyces marama, D. polymorphus, Geotrichum sp., Pichia etchelsii, P. ohmeri, Rhodotorula glutinis, R. rubra, Rhodotorula sp., Saccharomyces cerevisiae, S. kluyiveri and Zygosaccharomyces sp. were also obtained. Dark colonies on Staib medium were never observed. The psittacine birds apparently serve as carriers for several Candida species or their perfect states and to a lesser extent for other opportunistic yeasts such as Rhodotorula, Trichosporon and Saccharomyces spp., which are considered part of the transient microbiota of the gastrointestinal tract. The most striking finding was the absence of Cryptococcus spp. among the isolates. The present survey confirms the role of pet birds in carrying potential zoonotic yeasts.

Induction of L-phenylalanine ammonia-lyase during utilization of phenylalanine as a carbon or nitrogen source in Rhodotorula glutinis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marusich, W.C.; Jensen, R.A.; Zamir, L.O.

Rhodotorula glutinis is a convenient source of L-phenylalanine ammonia-lyase, an enzyme that is useful as a biochemical reagent in the assay of L-phenylalanine. There have been previous descriptions of induced lyase production in complex medium where induction occurs late in exponential growth, suggesting a role in secondary metabolism such as is the case in higher plants. A higher specific activity of L-phenylalanine ammonia-lyase (sixfold higher than in complex medium) can be obtained during midexponential growth in a defined medium containing L-phenylalanine as the sole source of carbon. L-phenylalanine will also induce lyase synthesis during exponential growth in minimal medium inmore » which L-phenylalanine is the sole source of nitrogen. The appearance of lyase in complex medium supplemented with L-phenylalanine is probably triggered fortuitously by exhaustion late in growth of a prime source of nitrogen. In this study, R. glutinis appeared to express a single lyase enzyme, regardless of whether induction was nitrogen signaled or carbon signaled. Thin-layer chromatographic analysis of ether extracts prepared fom cultures induced with doubly labeled (U-/sup 14/C; ring-4-/sup 3/H) L-phenylalanine provided evidence of a catabolic sequence containing cinnamic acid, benzoic acid, and 4-hydroxybenzoic acid as degradative intermediates. 3,4-Dihydroxybenzoic acid was not identified as a catabolic intermediate.« less

Induction of L-phenylalanine ammonia-lyase during utilization of phenylalanine as a carbon or nitrogen source in Rhodotorula glutinis.

PubMed Central

Marusich, W C; Jensen, R A; Zamir, L O

1981-01-01

Rhodotorula glutinis is a convenient source of L-phenylalanine ammonia-lyase, an enzyme that is useful as a biochemical reagent in the assay of L-phenylalanine. There have been previous descriptions of induced lyase production in complex medium where induction occurs late in exponential growth, suggesting a role in secondary metabolism such as is the case in higher plants. A higher specific activity of L-phenylalanine ammonia-lyase (sixfold higher than a complex medium) can be obtained during midexponential growth in a defined medium containing L-phenylalanine as the sole source of carbon. L-Phenylalanine will also induce lyase synthesis during exponential growth in minimal in which L-phenylalanine is the sole source of nitrogen. The appearance of lyase in complex medium supplemented with L-phenylalanine is probably triggered fortuitously by exhaustion late in growth of a prime source of nitrogen. In this study, R. glutinis appeared to express a single lyase enzyme, regardless of whether induction was nitrogen signaled or carbon signaled. Thin-layer chromatographic analysis of ether extracts prepared from cultures induced with doubly labeled (U-14C; ring-4-3H) L-phenylalanine provided evidence of a catabolic sequence containing cinnamic acid, benzoic acid, and 4-hydroxybenzoic acid as degradative intermediates. 3,4-Dihydroxybenzoic acid was not identified as a catabolic intermediate. PMID:7195398

Efficacy of Rhodotorula glutinis and Spirulina platensis carotenoids in immunopotentiation of mice infected with Candida albicans SC5314 and Pseudomonas aeruginosa 35.

PubMed

El-Sheekh, M M; Mahmoud, Y A-G; Abo-Shady, A M; Hamza, W

2010-01-01

Enhancement of the immune response leading to protection against bacterial and fungal infections was shown using different schedules of immunization with microbial pigments and a polysaccharide. The group of mice given carotenoids of Rhodotorula glutinis (preparation I) and polysaccharide of Spitulina platensis (IV) survived for 2 weeks after Pseudomonas aeruginosa infection. The groups of mice given carotenoids (I), polysaccharide (IV), I+IV and with the crude phycocyanin of S. platensis (III)+IV survived for 2 weeks after Candida albicans infection. All other groups recorded a maximum level of mortality reaching 2 mice per group either after immunization or post-infection. Adding the carotenoids, phycocyanin and polysaccharides to food as additives might therefore enhance the human immune response against microbial infections.

Inhibitory effect of chromogenic culture media on the growth of Rhodotorula: relevance to the diagnosis of Rhodotorula spp. infections.

PubMed

Bellanger, Anne-Pauline; Grenouillet, Frédéric; François, Nadine; Skana, Florence; Millon, Laurence

2013-11-01

With the increasing incidence and diverse etiologies of fungal infections, chromogenic yeast culture media are increasingly used for routine diagnosis. Rhodotorula species, which are characterized by the production of carotenoid pigments, are considered as emerging opportunistic pathogens. We recently diagnosed two fungemia due to Rhodotorula spp. and noticed that in both cases, the yeast failed to grow in subculture on the chromogenic yeast culture medium. This study was thus undertaken to investigate more thoroughly the ability (or inability) of Rhodotorula species to grow on different commercially available chromogenic media for yeast. Eighteen Rhodotorula spp. were checked for their ability to grow on four chromogenic yeast culture media: CHROMagar Candida (BD), Candi 4 Select (Biorad), Brilliance Candida (Oxoid), and Candida ID 2 (BioMerieux). All the Rhodotorula spp. strains grew on Brilliance and Candida ID 2, while only six isolates grew on Candi 4, and seven on CHROMagar. Two chromogenic yeast culture media showed a significant inhibitory effect on the growth of Rhodotorula species. As all Rhodotorula species are resistant to echinocandins and fluconazole, it is essential to isolate and identify these yeast quickly to initiate appropriate amphotericin B antifungal treatment as early as possible. The choice of media for routine use should take into account the ability of different media to allow all emerging fungal pathogens to grow. © 2013 APMIS. Published by John Wiley & Sons Ltd.

Lipid and carotenoid production by Rhodotorula glutinis under irradiation/high-temperature and dark/low-temperature cultivation.

PubMed

Zhang, Zhiping; Zhang, Xu; Tan, Tianwei

2014-04-01

The capacity of lipid and carotenoid production by Rhodotorula glutinis was investigated under different irradiation conditions, temperatures and C/N ratios. The results showed that dark/low-temperature could enhance lipid content, while irradiation/high-temperature increased the yields of biomass and carotenoid. The optimum C/N ratio for production was between 80 and 100. A two-stage cultivation strategy was used for lipid and carotenoid production in a 5L fermenter. In the first stage, the maximum biomass reached 28.1g/L under irradiation/high-temperature. Then, the cultivation condition was changed to dark/low-temperature, and C/N ratio was adjusted to 90. After the second stage, the biomass, lipid content and carotenoid reached 86.2g/L, 26.7% and 4.2mg/L, respectively. More significantly, the yields of biomass and lipid were 43.1% and 11.5%, respectively. Lipids contained 79.7% 18C and 16.8% 16C fatty acids by GC analysis. HPLC quantified the main carotenoids were β-carotene (68.4%), torularhodin (21.5%) and torulene (10.1%). Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Effects of dissolved oxygen level on cell growth and total lipid accumulation in the cultivation of Rhodotorula glutinis.

PubMed

Yen, Hong-Wei; Zhang, Zhiyong

2011-07-01

The total amount of lipids produced in Rhodotorula glutinis is a subject which has attracted increasing attention due to the potential biodiesel conversion from these microbial oils. The effects of the dissolved oxygen (DO) level in lipid accumulation were examined in this study. Variations of different medium volumes (30, 40 and 50ml) and shaking speed (60, 150 and 210rpm) in the flask trials were adopted to explore the DO effects on lipid production. All of the results revealed that a low DO could retard cell growth, while enhancing lipid accumulation. The 5l-fermentor results also confirm that a low DO (25 ± 10%) batch could have higher lipid content than that of high DO batch (60 ± 10%). Nevertheless, the DO level would not obviously affect the lipid composition profile. Oleic acid (C18:1) was the primary fatty acid in both batches. Due to the slow biomass growth rate resulting from the low DO, a two-stage DO controlled strategy (consisting of a high DO stage and following a low DO stage) was performed to improve the cell growth and lipid accumulation simultaneously. However, the strategy was not successful on the enhancement of total lipid production as compared to other batches. Conclusively, even a low DO could retard cell growth; the total production of lipids in the batch with low DO was higher that of the high DO batch due to the enhancement of lipid accumulation. Therefore, the batch operation of R. glutinis at the low DO was suggested for the purpose of lipid production. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Optimization of pineapple pulp residue hydrolysis for lipid production by Rhodotorula glutinis TISTR5159 using as biodiesel feedstock.

PubMed

Tinoi, Jidapha; Rakariyatham, Nuansri

2016-08-01

The higher lipid productivity of Rhodotorula glutinis TISTR5159 was achieved by optimizing the pineapple pulp hydrolysis for releasing the high sugars content. The sequential simplex method operated by varied; solid-to-liquid ratio, sulfuric acid concentration, temperature, and hydrolysis time were successfully applied and the highest sugar content (83.2 g/L) evaluated at a solid-to-liquid ratio of 1:10.8, 3.2% sulfuric acid, 105 °C for 13.9 min. Moreover, the (NH4)2SO4 supplement enhanced the lipid productivity and gave the maximum yields of biomass and lipid of 15.2 g/L and 9.15 g/L (60.2%), respectively. The C16 and C18 fatty acids were found as main components included oleic acid (55.8%), palmitic acid (16.6%), linoleic acid (11.9%), and stearic acid (7.8%). These results present the possibility to convert the sugars in pineapple pulp hydrolysate to lipids. The fatty acid profile was also similar to vegetable oils. Thus, it could be used as potential feedstock for biodiesel production.

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

PubMed

Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

2012-07-01

To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7-23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09-93.48)% and (4.90-99.70)% v/v, respectively. This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans.

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp.

PubMed Central

Moussa, Ahmed; Noureddine, Djebli; Saad, Aissat; Abdelmelek, Meslem; Abdelkader, Benhalima

2012-01-01

Objective To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp. Methods Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains. Results The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7–23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09–93.48)% and (4.90–99.70)% v/v, respectively. Conclusions This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans. PMID:23569970

Yeasts of the genital region of patients attending the dermatology service at Hospital São Paulo, Brazil.

PubMed

Bentubo, Henri Donnarumma Levy; Mantovani, Ariane; Yamashita, Jane Tomimori; Gambale, Walderez; Fischman, Olga

2015-01-01

The knowledge of the diversity of yeasts that make up the skin microbiota of human beings is essential for the efficient monitoring of infections to which a person may be predisposed. This study identified yeasts comprising the genital skin microbiota of patients attending the Dermatology Service at the Hospital São Paulo-UNIFESP, Brazil. Samples were collected from the genital region of each patient and cultured on Sabouraud dextrose agar. Individual colonies were carefully transferred to tubes daily. Yeasts were identified based on classical methodologies and confirmed using a commercial kit. Eighty-three patients were included in the study. Approximately 80% were women and 20% were men. The average age was 55 years. Hypertension, diabetes, kidney transplant and AIDS were the main underlying diseases reported by the patients. The most prevalent yeasts were Candida parapsilosis (36.1%), Rhodotorula mucilaginosa (9.2%), Rhodotorula glutinis (8.3%), Candida tropicalis (5.5%) and Trichosporon inkin (1.8%). Approximately 78% of the isolates were obtained in pure cultures. Trichosporon inkin was isolated only from women, in contrast to literature describing a high prevalence in males. Our results suggest that Candida albicans is not the main yeast found on genital skin as previously thought, and opportunistic pathogens such as C. parapsilosis, C. tropicalis, Rhodotorula spp. and T. inkin make up the genital skin microbiota, representing a risk for infection in immunocompromised subjects. These results also indicate that women are carriers of T. inkin, the etiological agent of white piedra and trichosporonosis. Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Single cell oils of the cold-adapted oleaginous yeast Rhodotorula glacialis DBVPG 4785

PubMed Central

2010-01-01

Background The production of microbial lipids has attracted considerable interest during the past decade since they can be successfully used to produce biodiesel by catalyzed transesterification with short chain alcohols. Certain yeast species, including several psychrophilic isolates, are oleaginous and accumulate lipids from 20 to 70% of biomass under appropriate cultivation conditions. Among them, Rhodotorula glacialis is a psychrophilic basidiomycetous species capable to accumulate intracellular lipids. Results Rhodotorula glacialis DBVPG 4785 is an oleaginous psychrophilic yeast isolated from a glacial environment. Despite its origin, the strain abundantly grew and accumulated lipids between -3 to 20°C. The temperature did not influence the yield coefficients of both biomass and lipids production, but had positive effect on the growth rate and thus on volumetric productivity of lipid. In glucose-based media, cellular multiplication occurred first, while the lipogenic phase followed whenever the culture was limited by a nutrient other than glucose. The extent of the carbon excess had positive effects on triacylglycerols production, that was maximum with 120 g L-1 glucose, in terms of lipid concentration (19 g L-1), lipid/biomass (68%) and lipid/glucose yields (16%). Both glucose concentration and growth temperature influenced the composition of fatty acids, whose unsaturation degree decreased when the temperature or glucose excess increased. Conclusions This study is the first proposed biotechnological application for Rhodotorula glacialis species, whose oleaginous biomass accumulates high amounts of lipids within a wide range of temperatures through appropriate cultivation C:N ratio. Although R. glacialis DBVPG 4785 is a cold adapted yeast, lipid production occurs over a broad range of temperatures and it can be considered an interesting microorganism for the production of single cell oils. PMID:20863365

Using crude glycerol and thin stillage for the production of microbial lipids through the cultivation of Rhodotorula glutinis.

PubMed

Yen, Hong-Wei; Yang, Ya-Chun; Yu, Yi-Huan

2012-10-01

Single cell oils (SCO) produced from oleaginous microorganisms are a potential alternative oil feedstock for biodiesel production. The worldwide production of glycerol, a 10% (w/w) byproduct produced in the transesterfication process of oils converted to biodiesel, is increasing as more biodiesel is being produced. For the purposes of cost reduction, crude glycerol was regarded as a suitable carbon source for the cultivation of Rhodotorula glutinis. In addition to using renewable crude glycerol, waste solution collected from the brewing company (called thin stillage) was adopted as a substitute to replace a costly nitrogen source used in the medium. The results of using mixture of crude glycerol and thin stillage indicated about a 27% increase in total biomass as compared to that of using crude glycerol with a standard medium. Using glycerol instead of glucose as the carbon source could also alter the lipid profile, resulting in an increase in linolenic acid (C18:2) to comprise over 20% of the total lipid. Successfully using renewable crude glycerol and thin stillage for the cultivation of oleaginous microorganisms could greatly enhance the economic competition of biodiesel produced from SCO. Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Siderophores as iron storage compounds in the yeasts Rhodotorula minuta and Ustilago sphaerogena detected by in vivo Mössbauer spectroscopy

NASA Astrophysics Data System (ADS)

Matzanke, B. F.; Bill, E.; Trautwein, A. X.; Winkelmann, G.

1990-07-01

In the yeasts Rhodotorula minuta and Ustilago sphaerogena siderophores represent the main intracellular iron pool. We suggest a ferritin substituting function of these siderophores in addition to their role as iron transport agents. In Rhodotorula transport and storage siderophore is the same compound whereas in Ustilago the iron-storage siderophore is ferrichrome. Besides siderophores, merely two iron metabolites can be observed. Other iron-requiring compounds are at least one order of magnitude less abundant in these yeasts. The ferrous metabolite has been detected in many other microbial systems and seems to be of general occurence and importance.

The seasonal dynamics of yeast communities in the rhizosphere of soddy-podzolic soils

NASA Astrophysics Data System (ADS)

Golubtsova, Yu. V.; Glushakova, A. M.; Chernov, I. Yu.

2007-08-01

The annual dynamics of the number and taxonomic composition of yeast was studied in the rhizosphere of two plant species (Ajuga reptans L. and Taraxacum officinale Wigg.) in a forb-birch forest on soddy-podzolic soil. Eurybiont phyllobasidial cryptococci and red-pigmented phytobionts Rhodotorula glutinis were found to predominate in the phyllosphere of these plants, whereas the typical pedobionts Cryptococcus terricola and Cr. podzolicus occurred on the surface of roots and in the rhizosphere. The seasonal changes in the number and species composition of the yeast communities in the rhizosphere were more smooth as compared to those in the phyllosphere. In the period of active vegetation of the plants, the phytobiont yeasts develop over their whole surface, including the rhizoplane. Their number on the aboveground parts of the plants was significantly lower than that of the pedobiont forms. Thus, the above-and underground parts of the plants significantly differed in the composition of the dominant species of epiphytic yeasts.

Mimicking lichens: incorporation of yeast strains together with sucrose-secreting cyanobacteria improves survival, growth, ROS removal, and lipid production in a stable mutualistic co-culture production platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Tingting; Li, Chien-Ting; Butler, Kirk

The feasibility of heterotrophic-phototrophic symbioses was tested via pairing of yeast strains Cryptococcus curvatus, Rhodotorula glutinis, or Saccharomyces cerevisiae with a sucrose-secreting cyanobacterium Synechococcus elongatus. The phototroph S. elongatus showed no growth in standard BG-11 medium with yeast extract, but grew well in BG-11 medium alone or supplemented with yeast nitrogen base without amino acids (YNB w/o aa). Among three yeast species, C. curvatus and R. glutinis adapted well to the BG-11 medium supplemented with YNB w/o aa, sucrose, and various concentrations of NaCl needed to maintain sucrose secretion from S. elongatus, while growth of S. cerevisiae was highly dependentmore » on sucrose levels. R. glutinis and C. curvatus grew efficiently and utilized sucrose produced by the partner in co-culture. Co-cultures of S. elongatus and R. glutinis were sustained over 1 month in both batch and in semi-continuous culture, with the final biomass and overall lipid yields in the batch co-culture 40 to 60% higher compared to batch mono-cultures of S. elongatus. The co-cultures showed enhanced levels of palmitoleic and linoleic acids. Furthermore, cyanobacterial growth in co-culture with R. glutinis was significantly superior to axenic growth, as S. elongatus was unable to grow in the absence of the yeast partner when cultivated at lower densities in liquid medium. Accumulated reactive oxygen species was observed to severely inhibit axenic growth of cyanobacteria, which was efficiently alleviated through catalase supply and even more effectively with co-cultures of R. glutinis. In conclusion, the pairing of a cyanobacterium and eukaryotic heterotroph in the artificial lichen of this study demonstrates the importance of mutual interactions between phototrophs and heterotrophs, e.g., phototrophs provide a carbon source to heterotrophs, and heterotrophs assist phototrophic growth and survival by removing/eliminating oxidative stress. Our results establish

Mimicking lichens: incorporation of yeast strains together with sucrose-secreting cyanobacteria improves survival, growth, ROS removal, and lipid production in a stable mutualistic co-culture production platform

DOE PAGES

Li, Tingting; Li, Chien-Ting; Butler, Kirk; ...

2017-03-21

The feasibility of heterotrophic-phototrophic symbioses was tested via pairing of yeast strains Cryptococcus curvatus, Rhodotorula glutinis, or Saccharomyces cerevisiae with a sucrose-secreting cyanobacterium Synechococcus elongatus. The phototroph S. elongatus showed no growth in standard BG-11 medium with yeast extract, but grew well in BG-11 medium alone or supplemented with yeast nitrogen base without amino acids (YNB w/o aa). Among three yeast species, C. curvatus and R. glutinis adapted well to the BG-11 medium supplemented with YNB w/o aa, sucrose, and various concentrations of NaCl needed to maintain sucrose secretion from S. elongatus, while growth of S. cerevisiae was highly dependentmore » on sucrose levels. R. glutinis and C. curvatus grew efficiently and utilized sucrose produced by the partner in co-culture. Co-cultures of S. elongatus and R. glutinis were sustained over 1 month in both batch and in semi-continuous culture, with the final biomass and overall lipid yields in the batch co-culture 40 to 60% higher compared to batch mono-cultures of S. elongatus. The co-cultures showed enhanced levels of palmitoleic and linoleic acids. Furthermore, cyanobacterial growth in co-culture with R. glutinis was significantly superior to axenic growth, as S. elongatus was unable to grow in the absence of the yeast partner when cultivated at lower densities in liquid medium. Accumulated reactive oxygen species was observed to severely inhibit axenic growth of cyanobacteria, which was efficiently alleviated through catalase supply and even more effectively with co-cultures of R. glutinis. In conclusion, the pairing of a cyanobacterium and eukaryotic heterotroph in the artificial lichen of this study demonstrates the importance of mutual interactions between phototrophs and heterotrophs, e.g., phototrophs provide a carbon source to heterotrophs, and heterotrophs assist phototrophic growth and survival by removing/eliminating oxidative stress. Our results establish

Genome sequence of the oleaginous yeast Rhodotorula toruloides strain CGMCC 2.1609.

PubMed

Sambles, Christine; Middelhaufe, Sabine; Soanes, Darren; Kolak, Dagmara; Lux, Thomas; Moore, Karen; Matoušková, Petra; Parker, David; Lee, Rob; Love, John; Aves, Stephen J

2017-09-01

Most eukaryotic oleaginous species are yeasts and among them the basidiomycete red yeast, Rhodotorula ( Rhodosporidium ) toruloides (Pucciniomycotina) is known to produce high quantities of lipids when grown in nitrogen-limiting media, and has potential for biodiesel production. The genome of the CGMCC 2.1609 strain of this oleaginous red yeast was sequenced using a hybrid of Roche 454 and Illumina technology generating 13 × coverage. The de novo assembly was carried out using MIRA and scaffolded using MAQ and BAMBUS. The sequencing and assembly resulted in 365 scaffolds with total genome size of 33.4 Mb. The complete genome sequence of this strain was deposited in GenBank and the accession number is LKER00000000. The annotation is available on Figshare (doi:10.6084/m9.figshare.4754251).

Rhodotorula rosulata sp. nov., Rhodotorula silvestris sp. nov. and Rhodotorula straminea sp. nov., novel myo-inositol-assimilating yeast species in the Microbotryomycetes.

PubMed

Golubev, Wladyslav I; Scorzetti, Gloria

2010-10-01

Three novel species are described as Rhodotorula rosulata sp. nov. (type strain VKM Y-2962(T) =CBS 10977(T)), Rhodotorula silvestris sp. nov. (type strain VKM Y-2971(T) =CBS 11420(T)) and Rhodotorula straminea sp. nov. (type strain VKM Y-2964(T) =CBS 10976(T)) based on the study of eight isolates from needle litter. The new species, phylogenetically located within the Microbotryomycetes, are related to glucuronate-assimilating species of the genus Rhodotorula. Sequencing of the D1/D2 domains of the LSU rDNA gene and the internal transcribed spacer (ITS) region, as well as physiological characterization, revealed their distinct taxonomic positions.

Cryptococcus lacticolor sp. nov. and Rhodotorula oligophaga sp. nov., novel yeasts isolated from the nasal smear microbiota of Queensland koalas kept in Japanese zoological parks.

PubMed

Satoh, Kazuo; Maeda, Mari; Umeda, Yoshiko; Sugamata, Miho; Makimura, Koichi

2013-07-01

A total of 515 yeast strains were isolated from the nasal smears of Queensland koalas and their breeding environments in Japanese zoological parks between 2005 and 2012. The most frequent species in the basidiomycetous yeast biota isolated from koala nasal passages was Cryptococcus neoformans, followed by Rhodotorula minuta. R. minuta was the most frequent species in the breeding environments, while C. neoformans was rare. Seven strains representing two novel yeast species were identified. Analyses of the 26S rDNA (LSU) D1/D2 domain and nuclear ribosomal DNA internal transcribed spacer region sequences indicated that these strains represent new species with close phylogenetic relationships to Cryptococcus and Rhodotorula. A sexual state was not found for either of these two novel yeasts. Key phenotypic characters confirmed that these strains could be placed in Cryptococcus and Rhodotorula. The names Cryptococcus lacticolor sp. nov. (type strain TIMM 10013(T) = JCM 15449(T) = CBS 10915(T) = DSM 21093(T), DDBJ/EMBL/Genbank Accession No.; AB375774 (ITS) and AB375775 (26S rDNA D1/D2 region), MycoBank ID; MB 802688, Fungal Barcoding Database ID; 3174), and Rhodotorula oligophaga sp. nov. (type strain TIMM 10017(T) = JCM 18398(T) = CBS 12623(T) = DSM 25814(T), DDBJ/EMBL/Genbank Accession No.; AB702967 (ITS) and AB702967 (26S rDNA D1/D2 region), MycoBank ID; MB 802689, Fungal Barcoding Database ID; 3175) are proposed for these new species.

A case of cutaneous Rhodotorula infection mimicking cryptococcosis.

PubMed

George, S M C; Quante, M; Cubbon, M D; MacDiarmaid-Gordon, A R; Topham, E J

2016-12-01

Rhodotorula is a ubiquitous environmental and commensal yeast, and an emerging opportunistic pathogen, particularly in immunocompromised individuals. Clinical infections with Rhodotorula have been increasingly recognized over the past 30 years; however, infections in solid-organ transplant recipients are uncommon, and cutaneous manifestations have rarely been reported. We describe a 59-year-old male renal transplant recipient, who developed cutaneous infection with Rhodotorula upon failure of his graft and commencement of haemodialysis. © 2016 British Association of Dermatologists.

Biodegradation of lindane using a novel yeast strain, Rhodotorula sp. VITJzN03 isolated from agricultural soil.

PubMed

Abdul Salam, Jaseetha; Lakshmi, V; Das, Devlina; Das, Nilanjana

2013-03-01

Lindane is a notorious organochlorine pesticide due to its high toxicity, persistence in the environment and its tendency to bioaccumulate. A yeast strain isolated from sorghum cultivation field was able to use lindane as carbon and energy source under aerobic conditions. With molecular techniques, it was identified and named as Rhodotorula strain VITJzN03. The effects of nutritional and environmental factors on yeast growth and the biodegradation of lindane was investigated. The maximum production of yeast biomass along with 100 % lindane mineralization was noted at an initial lindane concentration of 600 mg l(-1) within a period of 10 days. Lindane concentration above 600 mg l(-1) inhibited the growth of yeast in liquid medium. A positive relationship was noted between the release of chloride ions and the increase of yeast biomass as well as degradation of lindane. The calculated degradation rate and half life of lindane were found to be 0.416 day(-1) and 1.66 days, respectively. The analysis of the metabolites using GC-MS identified the formation of seven intermediates including γ-pentachlorocyclohexane(γ-PCCH), 1,3,4,6-tetrachloro-1,4-cyclohexadiene(1,4-TCCHdiene), 1,2,4-trichlorobenzene (1,2,4 TCB), 1,4-dichlorobenzene (1,4 DCB), chloro-cis-1,2-dihydroxycyclohexadiene (CDCHdiene), 3-chlorocatechol (3-CC) and maleylacetate (MA) derivatives indicating that lindane degradation follows successive dechlorination and oxido-reduction. Based on the results of the present study, the possible pathway for lindane degradation by Rhodotorula sp. VITJzN03 has been proposed. To the best of our knowledge, this is the first report on lindane degradation by yeast which can serve as a potential agent for in situ bioremediation of medium to high level lindane-contaminated sites.

Rhodotorula taiwanensis MD1149 produces hypoacetylated PEFA compounds with increased surface activity compared to Rhodotorula babjevae MD1169

PubMed Central

Rubinfeld, Bonnee; Leif, Roald; Mulcahy, Heather; Dugan, Lawrence; Souza, Brian

2018-01-01

Biosurfactants have several desirable characteristics in the industrial sector: detergency, antimicrobial effects, skin hydration, and emulsibility. Several yeast glycolipids are currently being utilized in these capacities: sophorolipids, ustilagic acid, and mannosylerythritol lipids (MELs). An emerging class of glycolipids, termed polyol esters of fatty acids (PEFA), have recently been reported for Rhodotorula babjevae, a basidiomycetous yeast species that secretes hyperacetylated congeners of PEFA (typically with 3–6 acetylation modifications). While screening Rhodotorula species for surfactant production, we identified a new environmental isolate identified as Rhodotorula taiwanensis MD1149 that dropped the surface tension of the liquid medium, indicating that it produced a potent biosurfactant. Acid depolymerization of the purified biosurfactants, followed by gas chromatography-mass spectrometry (GC-MS) analysis revealed that the biosurfactants were composed of PEFA compounds composed mainly of mannitol and arabitol esters of 3-hydroxy fatty acid, 3-methoxy fatty acid, and fatty acids with a single double bond; chain lengths were mainly C16 and C18. Liquid chromatography-mass spectrometry (LC-MS) confirmed the predicted accurate mass of these compounds. Interestingly, PEFA compounds produced by Rhodotorula taiwanensis MD1149 were more surface active due to their hypoacetylation profile (0–4 acetylation modifications) compared to Rhodotorula babjevae MD1169. These disparate surface active properties, based on acetylation, change the hydrophilic-lipophilic balance (HLB) of these compounds, and their potential utility within industrial applications. PMID:29293588

Rhodotorula taiwanensis MD1149 produces hypoacetylated PEFA compounds with increased surface activity compared to Rhodotorula babjevae MD1169.

PubMed

Lyman, Mathew; Rubinfeld, Bonnee; Leif, Roald; Mulcahy, Heather; Dugan, Lawrence; Souza, Brian

2018-01-01

Biosurfactants have several desirable characteristics in the industrial sector: detergency, antimicrobial effects, skin hydration, and emulsibility. Several yeast glycolipids are currently being utilized in these capacities: sophorolipids, ustilagic acid, and mannosylerythritol lipids (MELs). An emerging class of glycolipids, termed polyol esters of fatty acids (PEFA), have recently been reported for Rhodotorula babjevae, a basidiomycetous yeast species that secretes hyperacetylated congeners of PEFA (typically with 3-6 acetylation modifications). While screening Rhodotorula species for surfactant production, we identified a new environmental isolate identified as Rhodotorula taiwanensis MD1149 that dropped the surface tension of the liquid medium, indicating that it produced a potent biosurfactant. Acid depolymerization of the purified biosurfactants, followed by gas chromatography-mass spectrometry (GC-MS) analysis revealed that the biosurfactants were composed of PEFA compounds composed mainly of mannitol and arabitol esters of 3-hydroxy fatty acid, 3-methoxy fatty acid, and fatty acids with a single double bond; chain lengths were mainly C16 and C18. Liquid chromatography-mass spectrometry (LC-MS) confirmed the predicted accurate mass of these compounds. Interestingly, PEFA compounds produced by Rhodotorula taiwanensis MD1149 were more surface active due to their hypoacetylation profile (0-4 acetylation modifications) compared to Rhodotorula babjevae MD1169. These disparate surface active properties, based on acetylation, change the hydrophilic-lipophilic balance (HLB) of these compounds, and their potential utility within industrial applications.

Specific features of the dynamics of epiphytic and soil yeast communities in the thickets of Indian balsam on mucky gley soil

NASA Astrophysics Data System (ADS)

Glushakova, A. M.; Kachalkin, A. V.; Chernov, I. Yu.

2011-08-01

The annual dynamics of the number and taxonomic composition of yeast communities were studied in the phyllosphere, on the flowers, and on the roots of Indian balsam ( Impatiens glandulifera Royle) and in the mucky gley soil under the thickets of this plant. It was shown that typical phyllosphere yeast communities with a predominance of the red-pigmented species Rhodotorula mucilaginosa and Rhodotorula glutinis and the typical epiphyte Cryptococcus magnus are formed on the leaves of this annual hygrophyte. However, yeast groups with a predominance of the ascosporous species Saccharomyces paradoxus, Kazachstania barnettii, and Torulaspora delbrueckii, which are not typical of soils at all, were found in the mucky gley soil under the thickets of Indian balsam. Thus, the epiphytic and soil yeast complexes under the thickets of Indian balsam are represented by two entirely discrete communities without common species. In other biogeocenoses of the forest zone, the rearrangement of the structure of yeast communities in passing from the aboveground substrates to the soil proceeds gradually, and most of the species can be isolated both from the aboveground parts of plants and from the soil. The strong difference between the yeast communities in the phyllosphere of Indian balsam and in the soil under its thickets is apparently related to the fact that the annual hygrophytes are decomposed very quickly (during several days after the first frosts). Because of this, an intermediate layer between the phyllosphere and the soil (the litter layer), in which epiphytic microorganisms can develop, is not formed under these plants.

Use of PCR-restriction fragment length polymorphism analysis for identification of yeast species isolated from bovine intramammary infection.

PubMed

Fadda, M E; Pisano, M B; Scaccabarozzi, L; Mossa, V; Deplano, M; Moroni, P; Liciardi, M; Cosentino, S

2013-01-01

This study reports a rapid PCR-based technique using a one-enzyme RFLP for discrimination of yeasts isolated from bovine clinical and subclinical mastitis milk samples. We analyzed a total of 1,486 milk samples collected over 1 yr in south Sardinia and northern Italy, and 142 yeast strains were preliminarily grouped based on their cultural morphology and physiological characteristics. Assimilation tests were conducted using the identification kit API ID 32C and APILAB Plus software (bioMérieux, Marcy l'Etoile, France). For PCR-RFLP analysis, the 18S-ITS1-5.8S ribosomal(r)DNA region was amplified and then digested with HaeIII, and dendrogram analysis of RFLP fragments was carried out. Furthermore, within each of the groups identified by the API or PCR-RFLP methods, the identification of isolates was confirmed by sequencing of the D1/D2 region using an ABI Prism 310 automatic sequencer (Applied Biosystems, Foster City, CA). The combined phenotypic and molecular approach enabled the identification of 17 yeast species belonging to the genera Candida (47.9%), Cryptococcus (21.1%), Trichosporon (19.7%), Geotrichum (7.1%), and Rhodotorula (4.2%). All Candida species were correctly identified by the API test and their identification confirmed by sequencing. All strains identified with the API system as Geotrichum candidum, Cryptococcus uniguttulatus, and Rhodotorula glutinis also produced characteristic restriction patterns and were confirmed as Galactomyces geotrichum (a teleomorph of G. candidum), Filobasidium uniguttulatum (teleomorph of Crypt. uniguttulatus), and R. glutinis, respectively, by D1/D2 rDNA sequencing. With regard to the genus Trichosporon, preliminary identification by API was problematic, whereas the RFLP technique used in this study gave characteristic restriction profiles for each species. Moreover, sequencing of the D1/D2 region allowed not only successful identification of Trichosporon gracile where API could not, but also correct identification of

Some Properties of Extracellular Acetylxylan Esterase Produced by the Yeast Rhodotorula mucilaginosa†

PubMed Central

Lee, Hung; To, Rebecca J. B.; Latta, Roger K.; Biely, Peter; Schneider, Henry

1987-01-01

The red yeast Rhodotorula mucilaginosa produced an esterase that accumulated in the culture supernatant on induction with triacetin. The enzyme was specific for substrates bearing an O-acetyl group, but was relatively nonspecific for the rest of the molecule, which could consist of a phenol, a monosaccharide, a polysaccharide, or an aliphatic alcohol. The esterase was more active against acetylxylan and glucose β-d-pentaacetate than were a number of esterases from plant and animal sources, when activities on 4-nitrophenyl acetate were compared. The enzyme exhibited Michaelis-Menten kinetics and was active over a broad pH range (5.5 to 9.2), with an optimum between pH 8 and 10. In addition, the enzyme retained its activity for 2 h at 55°C. The yeast that produced the enzyme did not produce xylanase and, hence, is of interest for the production of acetylxylan esterase that is free of xylanolytic activity. PMID:16347498

Efficient preparation of enantiopure D-phenylalanine through asymmetric resolution using immobilized phenylalanine ammonia-lyase from Rhodotorula glutinis JN-1 in a recirculating packed-bed reactor.

PubMed

Zhu, Longbao; Zhou, Li; Huang, Nan; Cui, Wenjing; Liu, Zhongmei; Xiao, Ke; Zhou, Zhemin

2014-01-01

An efficient enzymatic process was developed to produce optically pure D-phenylalanine through asymmetric resolution of the racemic DL-phenylalanine using immobilized phenylalanine ammonia-lyase (RgPAL) from Rhodotorula glutinis JN-1. RgPAL was immobilized on a modified mesoporous silica support (MCM-41-NH-GA). The resulting MCM-41-NH-GA-RgPAL showed high activity and stability. The resolution efficiency using MCM-41-NH-GA-RgPAL in a recirculating packed-bed reactor (RPBR) was higher than that in a stirred-tank reactor. Under optimal operational conditions, the volumetric conversion rate of L-phenylalanine and the productivity of D-phenylalanine reached 96.7 mM h⁻¹ and 0.32 g L⁻¹ h⁻¹, respectively. The optical purity (eeD) of D-phenylalanine exceeded 99%. The RPBR ran continuously for 16 batches, the conversion ratio did not decrease. The reactor was scaled up 25-fold, and the productivity of D-phenylalanine (eeD>99%) in the scaled-up reactor reached 7.2 g L⁻¹ h⁻¹. These results suggest that the resolution process is an alternative method to produce highly pure D-phenylalanine.

Efficient Preparation of Enantiopure D-Phenylalanine through Asymmetric Resolution Using Immobilized Phenylalanine Ammonia-Lyase from Rhodotorula glutinis JN-1 in a Recirculating Packed-Bed Reactor

PubMed Central

Huang, Nan; Cui, Wenjing; Liu, Zhongmei; Xiao, Ke; Zhou, Zhemin

2014-01-01

An efficient enzymatic process was developed to produce optically pure D-phenylalanine through asymmetric resolution of the racemic DL-phenylalanine using immobilized phenylalanine ammonia-lyase (RgPAL) from Rhodotorula glutinis JN-1. RgPAL was immobilized on a modified mesoporous silica support (MCM-41-NH-GA). The resulting MCM-41-NH-GA-RgPAL showed high activity and stability. The resolution efficiency using MCM-41-NH-GA-RgPAL in a recirculating packed-bed reactor (RPBR) was higher than that in a stirred-tank reactor. Under optimal operational conditions, the volumetric conversion rate of L-phenylalanine and the productivity of D-phenylalanine reached 96.7 mM h−1 and 0.32 g L−1 h−1, respectively. The optical purity (ee D) of D-phenylalanine exceeded 99%. The RPBR ran continuously for 16 batches, the conversion ratio did not decrease. The reactor was scaled up 25-fold, and the productivity of D-phenylalanine (ee D>99%) in the scaled-up reactor reached 7.2 g L−1 h−1. These results suggest that the resolution process is an alternative method to produce highly pure D-phenylalanine. PMID:25268937

Hg tolerance and biouptake of an isolated pigmentation yeast Rhodotorula mucilaginosa.

PubMed

Liu, Bing; Wang, Chaogang; Liu, Danxia; He, Ning; Deng, Xu

2017-01-01

A pigmented yeast R1 with strong tolerance to Hg2+ was isolated. Phylogenetic identification based on the analysis of 26S rDNA and ITS revealed R1 is a Rhodotorula mucilaginosa species. R1 was able to grow in the presence of 80 mg/L Hg2+, but the lag phase was much prolonged compared to its growth in the absence of Hg2+. The maximum Hg2+ binding capacity of R1 was 69.9 mg/g, and dead cells could bind 15% more Hg2+ than living cells. Presence of organic substances drastically reduced bioavailability of Hg2+ and subsequently decreased Hg2+ removal ratio from aqueous solution, but this adverse effect could be remarkably alleviated by the simultaneous process of cell propagation and Hg2+ biouptake with actively growing R1. Furthermore, among the functional groups involved in Hg2+ binding, carboxyl group contributed the most, followed by amino & hydroxyl group and phosphate group. XPS analysis disclosed the mercury species bound on yeast cells was HgCl2 rather than HgO or Hg0.

Hg tolerance and biouptake of an isolated pigmentation yeast Rhodotorula mucilaginosa

PubMed Central

Liu, Bing; Wang, Chaogang; Liu, Danxia; He, Ning; Deng, Xu

2017-01-01

A pigmented yeast R1 with strong tolerance to Hg2+ was isolated. Phylogenetic identification based on the analysis of 26S rDNA and ITS revealed R1 is a Rhodotorula mucilaginosa species. R1 was able to grow in the presence of 80 mg/L Hg2+, but the lag phase was much prolonged compared to its growth in the absence of Hg2+. The maximum Hg2+ binding capacity of R1 was 69.9 mg/g, and dead cells could bind 15% more Hg2+ than living cells. Presence of organic substances drastically reduced bioavailability of Hg2+ and subsequently decreased Hg2+ removal ratio from aqueous solution, but this adverse effect could be remarkably alleviated by the simultaneous process of cell propagation and Hg2+ biouptake with actively growing R1. Furthermore, among the functional groups involved in Hg2+ binding, carboxyl group contributed the most, followed by amino & hydroxyl group and phosphate group. XPS analysis disclosed the mercury species bound on yeast cells was HgCl2 rather than HgO or Hg0. PMID:28253367

Mechanism-based site-directed mutagenesis to shift the optimum pH of the phenylalanine ammonia-lyase from Rhodotorula glutinis JN-1.

PubMed

Zhu, Longbao; Zhou, Li; Cui, Wenjing; Liu, Zhongmei; Zhou, Zhemin

2014-09-01

Phenylalanine ammonia-lyase ( Rg PAL) from Rhodotorula glutinis JN-1 stereoselectively catalyzes the conversion of the l-phenylalanine into trans -cinnamic acid and ammonia, and was used in chiral resolution of dl-phenylalanine to produce the d-phenylalanine under acidic condition. However, the optimum pH of Rg PAL is 9 and the Rg PAL exhibits low catalytic efficiency at acidic side. Therefore, a mutant Rg PAL with a lower optimum pH is expected. Based on catalytic mechanism and structure analysis, we constructed a mutant Rg PAL-Q137E by site-directed mutagenesis, and found that this mutant had an extended optimum pH 7-9 with activity of 1.8-fold higher than that of the wild type at pH 7. As revealed by Friedel-Crafts-type mechanism of Rg PAL, the improvement of the Rg PAL-Q137E might be due to the negative charge of Glu137 which could stabilize the intermediate transition states through electrostatic interaction. The Rg PAL-Q137E mutant was used to resolve the racemic dl-phenylalanine, and the conversion rate and the ee D value of d-phenylalanine using Rg PAL-Q137E at pH 7 were increased by 29% and 48%, and achieved 93% and 86%, respectively. This work provides an effective strategy to shift the optimum pH which is favorable to further applications of Rg PAL.

Rhodotorula fungemia of an intensive care unit patient and review of published cases.

PubMed

Spiliopoulou, Anastasia; Anastassiou, Evangelos D; Christofidou, Myrto

2012-10-01

Rhodotorula species are commensal yeasts that have emerged as a cause of life-threatening fungemia in severely immunocompromised patients. A case of Rhodotorula mucilaginosa fungemia in a 48-year-old woman that had undergone consecutive abdominal surgeries due to ovarian cancer and bowel necrosis while she was receiving fluconazole prophylaxis is presented. Several risk factors were identified such as presence of central venous catheters, solid organ neoplasm, abdominal surgery and administration of antibiotics. Identification was performed using commercial systems. The yeast was resistant to fluconazole, posaconazole and voriconazole and to echinocandins, whereas MIC to amphotericin B was 1.5 mg/L. Furthermore, published cases of Rhodotorula spp fungemia during the last decade are reviewed. In conclusion, Rhodotorula spp must be considered a potential pathogen in patients with immunosupression and central venous catheters. Correct identification is mandatory for appropriate management, as Rhodotorula spp are resistant to antifungal agents, such as fluconazole and echinocandins.

Early changes in shoot transcriptome of rice in response to Rhodotorula mucilaginosa JGTA-S1

PubMed Central

Saha, Chinmay; Seal, Anindita

2015-01-01

Yeasts of Rhodotorula genus have been reported to show endophytic colonization in different plants. Some of the Rhodotorula species are found to exhibit plant growth promoting activities and also have been reported to protect plants against invading pathogens. A yeast strain closely related to Rhodotorula mucilaginosa was isolated from the endosphere of Typha angustifolia collected from a Uranium mine. A microarray analysis was performed to investigate the early changes in rice shoot transcripts in response to this yeast (R. mucilaginosa JGTA-S1). Transcriptional changes were monitored in 6 h and 24 h treated rice plant shoots as compared to 0 h control. The microarray data has been submitted to the NCBI GEO repository under the accession number of GSE64321. PMID:26697384

Yeast diversity and dynamics in the production processes of Norwegian dry-cured meat products.

PubMed

Asefa, Dereje T; Møretrø, Trond; Gjerde, Ragnhild O; Langsrud, Solveig; Kure, Cathrine F; Sidhu, Maan S; Nesbakken, Truls; Skaar, Ida

2009-07-31

This study investigate the diversity and dynamics of yeasts in the production processes of one unsmoked and two smoked dry-cured meat products of a Norwegian dry-cured meat production facility. A longitudinal observational study was performed to collect 642 samples from the meat, production materials, room installations and indoor and outdoor air of the production facility. Nutrient rich agar media were used to isolate the yeasts. Morphologically different isolates were re-cultivated in their pure culture forms. Both classical and molecular methods were employed for species identification. Totally, 401 yeast isolates belonging to 10 species of the following six genera were identified: Debaryomyces, Candida, Rhodotorula, Rhodosporidium, Cryptococcus and Sporidiobolus. Debaryomyces hansenii and Candida zeylanoides were dominant and contributed by 63.0% and 26.4% respectively to the total isolates recovered from both smoked and unsmoked products. The yeast diversity was higher at the pre-salting production processes with C. zeylanoides being the dominant. Later at the post-salting stages, D. hansenii occurred frequently. Laboratory studies showed that D. hansenii was more tolerant to sodium chloride and nitrite than C. zeylanoides. Smoking seems to have a killing or a temporary growth inhibiting effect on yeasts that extend to the start of the drying process. Yeasts were isolated only from 31.1% of the environmental samples. They belonged to six different species of which five of them were isolated from the meat samples too. Debaryomyces hansenii and Rhodotorula glutinis were dominant with a 62.6% and 22.0% contribution respectively. As none of the air samples contained D. hansenii, the production materials and room installations used in the production processes were believed to be the sources of contamination. The dominance of D. hansenii late in the production process replacing C. zeylanoides should be considered as a positive change both for the quality and safety

Phenylalanine ammonia-lyase. Induction and purification from yeast and clearance in mammals.

PubMed

Fritz, R R; Hodgins, D S; Abell, C W

1976-08-10

Yeast phenylalanine ammonia-lyase (EC 4.3.1.5) catalyzes the deamination of L-phenylalanine to form trans-cinnamic acid and tyrosine to trans-coumaric acid. Maximal enzyme activity in Rhodotorula glutinis (2 units/g, wet weight, of yeast) was induced in late-log phase (12 to 14 hours) of growth in a culture medium containing 1.0% malt extract, 0.1% yeast extract, and 0.1% L-phenylalanine. A highly purified enzyme was obtained by fractionation with ammonium sulfate and sodium citrate followed by chromatography on DEAE-cellulose and Sephadex G-200. The active preparation yielded a major component on three different polyacrylamide gel electrophoretic systems. Antisera to phenylalanine ammonia-lyase was raised in rabbits and detected by double immunodiffusion. The antigen-antibody complex was enzymatically active in vitro. The biological half-life of the enzyme was approximately 21 hours in several mammalian species (mice without and with BW10232 adenocarcinoma and B16 melanoma, rats, and monkeys) after a single injection; however, upon repeated administration, phenylalanine ammonia-lyase had a much shorter biological half-life. The onset of rapid clearance occurred earlier in tumor-bearing than in nontumor-bearing mice indicating a direct or indirect influence by the tumor on the biological half-life of phenylalanine ammonia-lyase.

Bioprospecting microbes for single-cell oil production from starchy wastes.

PubMed

Chaturvedi, Shivani; Kumari, Arti; Nain, Lata; Khare, Sunil K

2018-03-16

Production of lipid from oleaginous yeast using starch as a carbon source is not a common practice; therefore, the purpose of this investigation was to explore the capability of starch assimilating microbes to produce oil, which was determined in terms of biomass weight, productivity, and lipid yield. Saccharomyces pastorianus, Rhodotorula mucilaginosa, Rhodotorula glutinis, and fungal isolate Ganoderma wiiroense were screened for the key parameters. The optimization was also performed by one-factor-at-a-time approach. Considering the specific yield of lipid and cell dry weight yield, R. glutinis and R. mucilaginosa showed superiority over other strains. G. wiiroense, a new isolate, would also be a promising strain for starch waste utilization in terms of extracellular and intracellular specific yield of lipids. Extracellular specific yield of lipid was highest in R. glutinis culture (0.025 g g -1 of biomass) followed by R. mucilaginosa (0.022 g g -1 of biomass) and G. wiiroense (0.020 g g -1 of biomass). Intracellular lipid was again highest in R. glutinis (0.048 g g -1 of biomass). The most prominent fatty acid methyl esters among the lipid as detected by GC-MS were saturated lipids mainly octadecanoic acid, tetradecanoate, and hexadecanoate. Extracellular lipid produced on starch substrate waste would be a cost-effective alternative for energy-intensive extraction process in biodiesel industry.

Developing a set of strong intronic promoters for robust metabolic engineering in oleaginous Rhodotorula (Rhodosporidium) yeast species.

PubMed

Liu, Yanbin; Yap, Sihui Amy; Koh, Chong Mei John; Ji, Lianghui

2016-11-25

Red yeast species in the Rhodotorula/Rhodosporidium genus are outstanding producers of triacylglyceride and cell biomass. Metabolic engineering is expected to further enhance the productivity and versatility of these hosts for the production of biobased chemicals and fuels. Promoters with strong activity during oil-accumulation stage are critical tools for metabolic engineering of these oleaginous yeasts. The upstream DNA sequences of 6 genes involved in lipid biosynthesis or accumulation in Rhodotorula toruloides were studied by luciferase reporter assay. The promoter of perilipin/lipid droplet protein 1 gene (LDP1) displayed much stronger activity (4-11 folds) than that of glyceraldehyde-3-phosphate dehydrogenase gene (GPD1), one of the strongest promoters known in yeasts. Depending on the stage of cultivation, promoter of acetyl-CoA carboxylase gene (ACC1) and fatty acid synthase β subunit gene (FAS1) exhibited intermediate strength, displaying 50-160 and 20-90% levels of GPD1 promoter, respectively. Interestingly, introns significantly modulated promoter strength at high frequency. The incorporation of intron 1 and 2 of LDP1 (LDP1in promoter) enhanced its promoter activity by 1.6-3.0 folds. Similarly, the strength of ACC1 promoter was enhanced by 1.5-3.2 folds if containing intron 1. The intron 1 sequences of ACL1 and FAS1 also played significant regulatory roles. When driven by the intronic promoters of ACC1 and LDP1 (ACC1in and LDP1in promoter, respectively), the reporter gene expression were up-regulated by nitrogen starvation, independent of de novo oil biosynthesis and accumulation. As a proof of principle, overexpression of the endogenous acyl-CoA-dependent diacylglycerol acyltransferase 1 gene (DGA1) by LDP1in promoter was significantly more efficient than GPD1 promoter in enhancing lipid accumulation. Intronic sequences play an important role in regulating gene expression in R. toruloides. Three intronic promoters, LDP1in, ACC1in and FAS1in, are

Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

NASA Astrophysics Data System (ADS)

Wang, Jufang; Lu, Dong; Wu, Xin; Sun, Haining; Ma, Shuang; Li, Renmin; Li, Wenjian

2010-09-01

To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV μm -1) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV μm -1. The mutation cross section saturated when LET was higher than 58.2 keV μm -1. Meanwhile, the highest RBE i for inactivation located at 120.0 keV μm -1 and the highest RBE m for mutation was at 58.2 keV μm -1. The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

Whole genome sequencing of Rhodotorula mucilaginosa isolated from the chewing stick (Distemonanthus benthamianus): insights into Rhodotorula phylogeny, mitogenome dynamics and carotenoid biosynthesis.

PubMed

Gan, Han Ming; Thomas, Bolaji N; Cavanaugh, Nicole T; Morales, Grace H; Mayers, Ashley N; Savka, Michael A; Hudson, André O

2017-01-01

In industry, the yeast Rhodotorula mucilaginosa is commonly used for the production of carotenoids. The production of carotenoids is important because they are used as natural colorants in food and some carotenoids are precursors of retinol (vitamin A). However, the identification and molecular characterization of the carotenoid pathway/s in species belonging to the genus Rhodotorula is scarce due to the lack of genomic information thus potentially impeding effective metabolic engineering of these yeast strains for improved carotenoid production. In this study, we report the isolation, identification, characterization and the whole nuclear genome and mitogenome sequence of the endophyte R. mucilaginosa RIT389 isolated from Distemonanthus benthamianus, a plant known for its anti-fungal and antibacterial properties and commonly used as chewing sticks. The assembled genome of R. mucilaginosa RIT389 is 19 Mbp in length with an estimated genomic heterozygosity of 9.29%. Whole genome phylogeny supports the species designation of strain RIT389 within the genus in addition to supporting the monophyly of the currently sequenced Rhodotorula species. Further, we report for the first time, the recovery of the complete mitochondrial genome of R. mucilaginosa using the genome skimming approach. The assembled mitogenome is at least 7,000 bases larger than that of Rhodotorula taiwanensis which is largely attributed to the presence of large intronic regions containing open reading frames coding for homing endonuclease from the LAGLIDADG and GIY-YIG families. Furthermore, genomic regions containing the key genes for carotenoid production were identified in R. mucilaginosa RIT389, revealing differences in gene synteny that may play a role in the regulation of the biotechnologically important carotenoid synthesis pathways in yeasts.

Whole genome sequencing of Rhodotorula mucilaginosa isolated from the chewing stick (Distemonanthus benthamianus): insights into Rhodotorula phylogeny, mitogenome dynamics and carotenoid biosynthesis

PubMed Central

Thomas, Bolaji N.; Cavanaugh, Nicole T.; Morales, Grace H.; Mayers, Ashley N.; Savka, Michael A.

2017-01-01

In industry, the yeast Rhodotorula mucilaginosa is commonly used for the production of carotenoids. The production of carotenoids is important because they are used as natural colorants in food and some carotenoids are precursors of retinol (vitamin A). However, the identification and molecular characterization of the carotenoid pathway/s in species belonging to the genus Rhodotorula is scarce due to the lack of genomic information thus potentially impeding effective metabolic engineering of these yeast strains for improved carotenoid production. In this study, we report the isolation, identification, characterization and the whole nuclear genome and mitogenome sequence of the endophyte R. mucilaginosa RIT389 isolated from Distemonanthus benthamianus, a plant known for its anti-fungal and antibacterial properties and commonly used as chewing sticks. The assembled genome of R. mucilaginosa RIT389 is 19 Mbp in length with an estimated genomic heterozygosity of 9.29%. Whole genome phylogeny supports the species designation of strain RIT389 within the genus in addition to supporting the monophyly of the currently sequenced Rhodotorula species. Further, we report for the first time, the recovery of the complete mitochondrial genome of R. mucilaginosa using the genome skimming approach. The assembled mitogenome is at least 7,000 bases larger than that of Rhodotorula taiwanensis which is largely attributed to the presence of large intronic regions containing open reading frames coding for homing endonuclease from the LAGLIDADG and GIY-YIG families. Furthermore, genomic regions containing the key genes for carotenoid production were identified in R. mucilaginosa RIT389, revealing differences in gene synteny that may play a role in the regulation of the biotechnologically important carotenoid synthesis pathways in yeasts. PMID:29158974

Rhodotorula mucilaginosa Fungemia and Pleural Tuberculosis in an Immunocompetent Patient: An Uncommon Association.

PubMed

Pereira, Cláudia; Ribeiro, Sofia; Lopes, Virgínia; Mendonça, Teresa

2016-02-01

We report an atypical case of Rhodotorula mucilaginosa fungemia coexisting with pleural tuberculosis, in an immunocompetent host. The patient was an inhaled drug abuser and worked in a fruit market. The diagnosis of Rhodotorula mucilaginosa infection was established by the isolation of the yeast in two blood cultures followed by a good response to amphotericin B treatment. Persistent evening fever and pleural effusion led to the second diagnosis-pleural tuberculosis. In the last 5 years, this was the only case of Rhodotorula mucilaginosa fungemia in our hospital and the first case in the literature that documents Rhodotorula mucilaginosa fungemia associated with pleural tuberculosis.

Heterotrophic cultivation of Chlorella pyrenoidosa using sucrose as the sole carbon source by co-culture with Rhodotorula glutinis.

PubMed

Wang, Shikai; Wu, Yong; Wang, Xu

2016-11-01

Heterotrophic cultivation of microalgae is a feasible alternative strategy to avoid the light limitation of photoautotrophic culture, but the heterotrophic utilization of disaccharides is difficult for microalgae. Aimed at this problem, a co-culture system was developed by mix culture of C. pyrenoidosa and R. glutinis using sucrose as the sole carbon source. In this system, C. pyrenoidosa could utilize glucose and fructose which were hydrolyzed from sucrose by R. glutinis. The highest specific growth rate and final cell number proportion of algae was 1.02day(-1) and 45%, respectively, when cultured at the initial algal cell number proportion of 95.24% and the final algal cell density was 111.48×10(6)cells/mL. In addition, the lipid content was also promoted due to the synergistic effects in mix culture. This study provides a novel approach using sucrose-riched wastes for the heterotrophic culture of microalgae and may effectively decrease the cost of carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular Identification, Antifungal Susceptibility Profile, and Biofilm Formation of Clinical and Environmental Rhodotorula Species Isolates

PubMed Central

Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona e

2013-01-01

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC50/MIC90, 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species

Molecular identification, antifungal susceptibility profile, and biofilm formation of clinical and environmental Rhodotorula species isolates.

PubMed

Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona E; Colombo, Arnaldo Lopes

2013-01-01

Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC(50)/MIC(90), 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula

Beneficial Effects of Rhodotorula sp. C11 on Growth and Disease Resistance of Juvenile Japanese Spiky Sea Cucumber Apostichopus japonicus.

PubMed

Yang, ZhiPing; Sun, JianMing; Xu, Zhe

2015-06-01

The purpose of this study was to evaluate the effects of dietary administration of the live yeast, Rhodotorula sp. C11, on growth and disease resistance against Vibrio splendidus infection in juvenile Japanese spiky sea cucumber Apostichopus japonicus. Sea cucumbers were fed diets containing Rhodotorula sp. C11 at 0 (control), 10⁴, 10⁵, and 10⁶ CFU/g of feed for 45 d. There were three replicate tanks per dietary treatment. The specific growth rates were higher in all sea cucumbers treated with Rhodotorula sp. C11 than in the controls. Following a challenge with V. splendidus NB13, the cumulative prevalence and mortality of sea cucumbers fed diets supplemented with Rhodotorula sp. C11 were lower than in animals fed the basal diet. In sea cucumbers fed diets supplemented with Rhodotorula sp. C11 for 42 d, the only viable yeast found in the intestine was Rhodotorula sp. C11, which had counts of 1.58-1.98 × 10⁴CFU/g. No yeast was isolated from the intestine of animals fed the basal diet. For the colonization study, 20 sea cucumbers from each dietary treatment were removed to separate tanks and fed the control diet from day 16 to day 46. The viable yeast (Rhodotorula sp. C11) counts in the intestine decreased to 60-80 CFU/g by day 37. Moreover, as demonstrated by denaturing gradient gel electrophoresis, Rhodotorula sp. C11 colonization of the intestine could be detected until day 46. The differences in culture and PCR-denaturing gradient gel electrophoresis may be due to differences in the sensitivity of both methods. The present result showed that Rhodotorula sp. C11 was able to successfully colonize the intestine of juvenile Japanese spiky sea cucumbers by dietary supplementation, which improved its growth and disease resistance.

Rhodotorula mucilaginosa Keratitis: a rare fungus from Eastern India.

PubMed

Saha, Suman; Sengupta, Jayangshu; Chatterjee, Debapriya; Banerjee, Debdulal

2014-03-01

Rhodotorula mucilaginosa rarely cause keratitis in immunocompromised individuals. A 30 year old male with history of minor trauma presented with cotton wool like stromal infiltration and hypopyon in left eye. Microbiological examination of corneal scraping showed fungal hyphae and yeast cells in direct smear. Molecular identification of the organism was performed which showed 100% homology with Rhodotorula mucilaginosa. Management of these cases is difficult often necessitating surgical procedures. However further reports are necessary to understand the disease and establish a treatment protocol.

Fungemia due to Rhodotorula mucilaginosa after allogeneic hematopoietic stem cell transplantation.

PubMed

Mori, T; Nakamura, Y; Kato, J; Sugita, K; Murata, M; Kamei, K; Okamoto, S

2012-02-01

Rhodotorula species have been increasingly recognized as emerging pathogens, particularly in immunocompromised patients. We herein report on a patient with myelodysplastic syndrome who developed fungemia due to Rhodotorula mucilaginosa after allogeneic hematopoietic stem cell transplantation (HSCT) from an unrelated donor. He developed severe acute graft-versus-host disease requiring high-dose steroids, and had serially been administered fluconazole and micafungin for the prophylaxis of fungal infection. Although several cases of Rhodotorula infection after HSCT have been reported, all of them were recipients of autologous HSCT, not allogeneic HSCT. A review of all the reported cases of Rhodotorula infection after HSCT revealed that all patients had received fluconazole or echinocandins before the onset of infection. The findings suggest that Rhodotorula species could be causative yeasts, particularly in patients receiving fluconazole or echinocandins, both of which are inactive against the species. © 2011 John Wiley & Sons A/S.

Simultaneous production of intracellular triacylglycerols and extracellular polyol esters of fatty acids by Rhodotorula babjevae and Rhodotorula aff. paludigena.

PubMed

Garay, Luis A; Sitepu, Irnayuli R; Cajka, Tomas; Cathcart, Erin; Fiehn, Oliver; German, J Bruce; Block, David E; Boundy-Mills, Kyria L

2017-10-01

Microbial oils have been analyzed as alternatives to petroleum. However, just a handful of microbes have been successfully adapted to produce chemicals that can compete with their petroleum counterparts. One of the reasons behind the low success rate is the overall economic inefficiency of valorizing a single product. This study presents a lab-scale analysis of two yeast species that simultaneously produce multiple high-value bioproducts: intracellular triacylglycerols (TG) and extracellular polyol esters of fatty acids (PEFA), two lipid classes with immediate applications in the biofuels and surfactant industries. At harvest, the yeast strain Rhodotorula aff. paludigena UCDFST 81-84 secreted 20.9 ± 0.2 g L -1 PEFA and produced 8.8 ± 1.0 g L -1 TG, while the yeast strain Rhodotorula babjevae UCDFST 04-877 secreted 11.2 ± 1.6 g L -1 PEFA and 18.5 ± 1.7 g L -1 TG. The overall glucose conversion was 0.24 and 0.22 g (total lipid) g (glucose) -1 , respectively. The results present a stable and scalable microbial growth platform yielding multiple co-products.

Rhodotorula mucilaginosa Keratitis: A rare fungus from Eastern India

PubMed Central

Saha, Suman; Sengupta, Jayangshu; Chatterjee, Debapriya; Banerjee, Debdulal

2014-01-01

Rhodotorula mucilaginosa rarely cause keratitis in immunocompromised individuals. A 30 year old male with history of minor trauma presented with cotton wool like stromal infiltration and hypopyon in left eye. Microbiological examination of corneal scraping showed fungal hyphae and yeast cells in direct smear. Molecular identification of the organism was performed which showed 100% homology with Rhodotorula mucilaginosa. Management of these cases is difficult often necessitating surgical procedures. However further reports are necessary to understand the disease and establish a treatment protocol. PMID:23619486

Proteomic study of the yeast Rhodotorula mucilaginosa RCL-11 under copper stress.

PubMed

Irazusta, Verónica; Estévez, Cristina; Amoroso, María Julia; de Figueroa, Lucía I C

2012-06-01

In order to understand the mechanism involved in Rhodotorula mucilaginosa RCL-11 resistance to copper a proteomic study was conducted. Atomic absorption spectroscopy showed that the copper concentration in the medium decreased from 0.5 to 0.19 mM 48 h after inoculation of the yeast. Analysis of one-dimensional gel electrophoresis of crude cell extracts revealed expression of differential bands between cells with and without copper. In order to study this difference, two-dimensional electrophoresis of R. mucilaginosa RCL-11 exposed to Cu for 16, 24, and 48 h was carried out. Identification of differentially expressed proteins was performed by MALDI-TOF/TOF. Ten of the 16 spots identified belonged to heat shock proteins. Superoxide dismutase, methionine synthase and beta-glucosidase were also found over-expressed at high copper concentrations. The results obtained in the present work show that when R. mucilaginosa RCL-11 is exposed to 0.5 mM copper, differential proteins, involved in cell resistance mechanisms, are expressed.

Tinea capitis-like infection caused by Rhodotorula mucilaginosa in a shelter for African Refugee Children in Northern Israel.

PubMed

Peretz, Avi; Nitzan, Orna; Freidus, Victoria; Kassem, Riad

2018-03-01

Rhodotorula is a genus of unicellular pigmented yeasts, part of the division Basidiomycota. In this article, we report three cases of refugee children in a day care shelter in northern Israel who were clinically diagnosed and treated empirically as with ringworm infection but with clean and exclusive growth of Rhodotorula mucilaginosa in repeated cultures of several skin samples. Skin infections caused by this yeast are rare and there are few reports in the literature, mainly in patients who are immunocompromised. Here we report an infectious process of the scalp in immunocompetent children, caused by Rhodotorula mucilaginosa mimicking tinea capitis. Copyright © 2017 Elsevier B.V. All rights reserved.

Rhodotorula fungemia: Report of two cases in Sfax (Tunisia).

PubMed

Guidara, R; Trabelsi, H; Neji, S; Cheikhrouhou, F; Sellami, H; Makni, F; Ayadi, A

2016-06-01

Rhodotorula is emerging as an important cause of nosocomial and opportunistic infections. We present two cases of Rhodotorula mucilaginosa fungemia diagnosed at our hospital during the last decade. The first case was of a term neonate who presented congenital heart disease (interventricular communication) and body dysmorphic disorder. He was admitted for respiratory failure and sepsis. The second case involved in a 33-year-old woman that had Hodgkinien lymphoma associated to tuberculosis. Identification was performed using commercial systems and confirmed by PCR sequencing of internal transcribed spacer, ITS1 and ITS2 regions of rDNA. Antifungal susceptibility tested by sensititre yeast revealed susceptibility to amphotericin B and resistance to fluconazole for the two strains. These cases emphasize the emerging importance of Rhodotorula sp. as a pathogen and it must be considered a potential pathogen in patients with immunosupression and with central venous catheters. Correct identification is mandatory for appropriate management, as Rhodotorula spp. are resistant to antifungal agents, such as fluconazole. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Occurrence and diversity of marine yeasts in Antarctica environments

NASA Astrophysics Data System (ADS)

Zhang, Xue; Hua, Mingxia; Song, Chunli; Chi, Zhenming

2012-03-01

A total of 28 yeast strains were obtained from the sea sediment of Antarctica. According to the results of routine identification and molecular characterization, the strains belonged to species of Yarrowia lipolytica, Debaryomyces hansenii, Rhodotorula slooffiae, Rhodotorula mucilaginosa, Sporidiobolus salmonicolor, Aureobasidium pullulans, Mrakia frigida and Guehomyces pullulans, respectively. The Antarctica yeasts have wide potential applications in biotechnology, for some of them can produce β-galactosidase and killer toxins.

Improvement in extracellular protease production by the marine antarctic yeast Rhodotorula mucilaginosa L7.

PubMed

Chaud, Luciana C S; Lario, Luciana D; Bonugli-Santos, Rafaella C; Sette, Lara D; Pessoa Junior, Adalberto; Felipe, Maria das Graças de A

2016-12-25

Microorganisms from extreme and restrictive eco systems, such as the Antarctic continent, are of great interest due to their ability to synthesize products of commercial value. Among these, enzymes from psychrotolerant and psychrophilic microorganisms offer potential economical benefits due to their high activity at low and moderate temperatures. The cold adapted yeast Rhodotorula mucilaginosa L7 was selected out of 97 yeasts isolated from Antarctica as having the highest extracellular proteolytic activity in preliminary tests. The present study was aimed at evaluating the effects of nutrient composition (peptone, rice bran extract, ammonium sulfate, sodium chloride) and physicochemical parameters (temperature and pH) on its proteolytic activity. A 2 6-2 fractional factorial design experiment followed by a central composite design (CCD 2 3 ) was performed to optimize the culture conditions and improve the extracellular proteolytic activity. The results indicated that the presence of peptone in the medium was the most influential factor in protease production. Enzymatic activity was enhanced by the interaction between low glucose and peptone concentrations. The optimization of culture conditions with the aid of mathematical modeling enabled a c. 45% increase in proteolytic activity and at the same time reduced the amount of glucose and peptone required for the culture. Thus culture conditions established in this work may be employed in the biotechnological production of this protease. Copyright © 2016 Elsevier B.V. All rights reserved.

[Groups and sources of yeasts in house dust].

PubMed

Glushakova, A M; Zheltikova, T M; Chernov, I Iu

2004-01-01

House dust contains bacteria, mycelial fungi, microarthropods, and yeasts. The house dust samples collected in 25 apartments in Moscow and the Moscow region were found to contain yeasts belonging to the genera Candida, Cryptococcus, Debaryomyces, Rhodotorula, Sporobolomyces, and Trichosporon. The most frequently encountered microorganisms were typical epiphytic yeasts, such as Cryptococcus diffluens and Rhodotorula mucilaginosa, which are capable of long-term preservation in an inactive state. The direct source of epiphytic yeasts occurring in the house dust might be the indoor plants, which were contaminated with these yeasts, albeit to a lesser degree than outdoor plants. Along with the typical epiphytic yeasts, the house dust contained the opportunistic yeast pathogens Candida catenulata, C. guillermondii, C. haemulonii, C. rugosa, and C. tropicalis, which are known as the causal agents of candidiasis. We failed to reveal any correlation between the abundance of particular yeast species in the house dust, residential characteristics, and the atopic dermatitis of the inhabitants.

Multiplatform Mass Spectrometry-Based Approach Identifies Extracellular Glycolipids of the Yeast Rhodotorula babjevae UCDFST 04-877.

PubMed

Cajka, Tomas; Garay, Luis A; Sitepu, Irnayuli R; Boundy-Mills, Kyria L; Fiehn, Oliver

2016-10-28

A multiplatform mass spectrometry-based approach was used for elucidating extracellular lipids with biosurfactant properties produced by the oleaginous yeast Rhodotorula babjevae UCDFST 04-877. This strain secreted 8.6 ± 0.1 g/L extracellular lipids when grown in a benchtop bioreactor fed with 100 g/L glucose in medium without addition of hydrophobic substrate, such as oleic acid. Untargeted reversed-phase liquid chromatography-quadrupole/time-of-flight mass spectrometry (QTOFMS) detected native glycolipid molecules with masses of 574-716 Da. After hydrolysis into the fatty acid and sugar components and hydrophilic interaction chromatography-QTOFMS analysis, the extracellular lipids were found to consist of hydroxy fatty acids and sugar alcohols. Derivatization and chiral separation gas chromatography-mass spectrometry (GC-MS) identified these components as d-arabitol, d-mannitol, (R)-3-hydroxymyristate, (R)-3-hydroxypalmitate, and (R)-3-hydroxystearate. In order to assemble these substructures back into intact glycolipids that were detected in the initial screen, potential structures were in-silico acetylated to match the observed molar masses and subsequently characterized by matching predicted and observed MS/MS fragmentation using the Mass Frontier software program. Eleven species of acetylated sugar alcohol esters of hydroxy fatty acids were characterized for this yeast strain.

Clinical and microbiological characteristics of Rhodotorula mucilaginosa infections in a tertiary-care facility.

PubMed

Capoor, M R; Aggarwal, S; Raghvan, C; Gupta, D K; Jain, A K; Chaudhary, R

2014-01-01

Rhodotorula spp. are an emergent opportunistic pathogen, particularly in immunocompromised individuals. The aim of the study was to review reported cases of Rhodotorula infection over a period of 9 years to determine epidemiology, risk factors, treatment and outcome. The Rhodotorula spp. were isolated from cerebrospinal fluid (9) and blood (5). The most common pre-disposing factors were prolonged hospital stay (>1 month) and prolonged usage of broad-spectrum antibiotics (>1 month). All the isolates were identified as R. mucilaginosa by conventional methods. Amphotericin B demonstrated lowest minimum inhibitory concentration (MIC) as compared with other anti-fungal agents (fluconazole, itraconazole and voriconazole). The recognition of unusual yeasts as an agent of life-threatening infection and their intrinsic resistance increases the burden on the mycology laboratory for complete species identification and to determine minimum inhibitory concentration.

Draft Genome Sequence of Rhodotorula mucilaginosa, an Emergent Opportunistic Pathogen

PubMed Central

Deligios, Massimo; Fraumene, Cristina; Abbondio, Marcello; Mannazzu, Ilaria; Tanca, Alessandro; Addis, Maria Filippa

2015-01-01

Rhodotorula mucilaginosa, a yeast with valuable biotechnological features, has also been recorded as an emergent opportunistic pathogen that might cause disease in both immunocompetent and immunocompromised individuals. Here, we report the draft genome sequence of R. mucilaginosa strain C2.5t1, which was isolated from cacao seeds in Cameroon. PMID:25858834

Novel endophytic yeast Rhodotorula mucilaginosa strain PTD3 II: production of xylitol and ethanol in the presence of inhibitors.

PubMed

Vajzovic, Azra; Bura, Renata; Kohlmeier, Kevin; Doty, Sharon L

2012-10-01

A systematic study was conducted characterizing the effect of furfural, 5-hydroxymethylfurfural (5-HMF), and acetic acid concentration on the production of xylitol and ethanol by a novel endophytic yeast, Rhodotorula mucilaginosa strain PTD3. The influence of different inhibitor concentrations on the growth and fermentation abilities of PTD3 cultivated in synthetic nutrient media containing 30 g/l xylose or glucose were measured during liquid batch cultures. Concentrations of up to 5 g/l of furfural stimulated production of xylitol to 77 % of theoretical yield (10 % higher compared to the control) by PTD3. Xylitol yields produced by this yeast were not affected in the presence of 5-HMF at concentrations of up to 3 g/l. At higher concentrations of furfural and 5-HMF, xylitol and ethanol yields were negatively affected. The higher the concentration of acetic acid present in a media, the higher the ethanol yield approaching 99 % of theoretical yield (15 % higher compared to the control) was produced by the yeast. At all concentrations of acetic acid tested, xylitol yield was lowered. PTD3 was capable of metabolizing concentrations of 5, 15, and 5 g/l of furfural, 5-HMF, and acetic acid, respectively. This yeast would be a potent candidate for the bioconversion of lignocellulosic sugars to biochemicals given that in the presence of low concentrations of inhibitors, its xylitol and ethanol yields are stimulated, and it is capable of metabolizing pretreatment degradation products.

Proteomic analysis of Rhodotorula mucilaginosa: dealing with the issues of a non-conventional yeast.

PubMed

Addis, Maria Filippa; Tanca, Alessandro; Landolfo, Sara; Abbondio, Marcello; Cutzu, Raffaela; Biosa, Grazia; Pagnozzi, Daniela; Uzzau, Sergio; Mannazzu, Ilaria

2016-08-01

Red yeasts ascribed to the species Rhodotorula mucilaginosa are gaining increasing attention, due to their numerous biotechnological applications, spanning carotenoid production, liquid bioremediation, heavy metal biotransformation and antifungal and plant growth-promoting actions, but also for their role as opportunistic pathogens. Nevertheless, their characterization at the 'omic' level is still scarce. Here, we applied different proteomic workflows to R. mucilaginosa with the aim of assessing their potential in generating information on proteins and functions of biotechnological interest, with a particular focus on the carotenogenic pathway. After optimization of protein extraction, we tested several gel-based (including 2D-DIGE) and gel-free sample preparation techniques, followed by tandem mass spectrometry analysis. Contextually, we evaluated different bioinformatic strategies for protein identification and interpretation of the biological significance of the dataset. When 2D-DIGE analysis was applied, not all spots returned a unambiguous identification and no carotenogenic enzymes were identified, even upon the application of different database search strategies. Then, the application of shotgun proteomic workflows with varying levels of sensitivity provided a picture of the information depth that can be reached with different analytical resources, and resulted in a plethora of information on R. mucilaginosa metabolism. However, also in these cases no proteins related to the carotenogenic pathway were identified, thus indicating that further improvements in sequence databases and functional annotations are strictly needed for increasing the outcome of proteomic analysis of this and other non-conventional yeasts. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Novel endophytic yeast Rhodotorula mucilaginosa strain PTD3 I: production of xylitol and ethanol.

PubMed

Bura, Renata; Vajzovic, Azra; Doty, Sharon L

2012-07-01

An endophytic yeast, Rhodotorula mucilaginosa strain PTD3, that was isolated from stems of hybrid poplar was found to be capable of production of xylitol from xylose, of ethanol from glucose, galactose, and mannose, and of arabitol from arabinose. The utilization of 30 g/L of each of the five sugars during fermentation by PTD3 was studied in liquid batch cultures. Glucose-acclimated PTD3 produced enhanced yields of xylitol (67% of theoretical yield) from xylose and of ethanol (84, 86, and 94% of theoretical yield, respectively) from glucose, galactose, and mannose. Additionally, this yeast was capable of metabolizing high concentrations of mixed sugars (150 g/L), with high yields of xylitol (61% of theoretical yield) and ethanol (83% of theoretical yield). A 1:1 glucose:xylose ratio with 30 g/L of each during double sugar fermentation did not affect PTD3's ability to produce high yields of xylitol (65% of theoretical yield) and ethanol (92% of theoretical yield). Surprisingly, the highest yields of xylitol (76% of theoretical yield) and ethanol (100% of theoretical yield) were observed during fermentation of sugars present in the lignocellulosic hydrolysate obtained after steam pretreatment of a mixture of hybrid poplar and Douglas fir. PTD3 demonstrated an exceptional ability to ferment the hydrolysate, overcome hexose repression of xylose utilization with a short lag period of 10 h, and tolerate sugar degradation products. In direct comparison, PTD3 had higher xylitol yields from the mixed sugar hydrolysate compared with the widely studied and used xylitol producer Candida guilliermondii.

Fermentation and aerobic metabolism of cellodextrins by yeasts. [Candida wickerhamii; C. guiliermondii; C. molischiana; Debaryomyces polymorphus; Pichia guilliermondii; Clavispora lusitaniae; Kluyveromyces lactis; Brettanomyces claussenii; Rhodotorula minuta; Dekkera intermedia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freer, S.N.

1991-03-01

The fermentation and aerobic metabolism of cellodextrins by 14 yeast species or strains was monitored. When grown aerobically, Candida wickerhamii, C. guilliermondii, and C. molischiana metabolized cellodextrins of degree of polymerization 3 to 6. C. wicherhamii and C. molischiana also fermented these substrates, while C. guilliermondii fermented only cellodextrins of degree of polymerization {<=} 3. Debaryomyces polymorphus, Pichia guilliermondii, Clavispora lusitaniae, and one of two strains of Kluyveromyces lactis metabolized glucose, cellobiose, and cellotriose when grown aerobically. These yeasts also fermented these substrates, except for K. lactis, which fermented only glucose and cellobiose. The remaining species/strains tested, K. lactis, Brettanomycesmore » claussenii, Brettanomyces anomalus, Kluyveromyces dobzhanskii, Rhodotorula minuta, and Dekkera intermedia, both fermented and aerobically metabolized glucose and cellobiose. Crude enzyme preparations from all 14 yeast species or strains were tested for ability to hydrolyze cellotriose and cellotretose. Most of the yeasts produced an enzyme(s) capable of hydrolyzing cellotriose. However, with two exceptions, R. minuta and P. guilliermondii, only the yeasts that metabolized cellodextrins of degree of polymerization >3 produced an enzyme(s) that hydrolyzed cellotretose.« less

Rhodotorula svalbardensis sp. nov., a novel yeast species isolated from cryoconite holes of Ny-Ålesund, Arctic.

PubMed

Singh, Purnima; Singh, Shiv M; Tsuji, Masaharu; Prasad, Gandham S; Hoshino, Tamotsu

2014-02-01

A psychrophilic yeast species was isolated from glacier cryoconite holes of Svalbard. Nucleotide sequences of the strains were studied using D1/D2 domain, ITS region and partial sequences of mitochondrial cytochrome b gene. The strains belonged to a clade of psychrophilic yeasts, but showed marked differences from related species in the D1/D2 domain and biochemical characters. Effects of temperature, salt and media on growth of the cultures were also studied. Screening of the cultures for amylase, cellulase, protease, lipase, urease and catalase activities was carried out. The strains expressed high amylase and lipase activities. Freeze tolerance ability of the isolates indicated the formation of unique hexagonal ice crystal structures due to presence of 'antifreeze proteins' (AFPs). FAME analysis of cultures showed a unique trend of increase in unsaturated fatty acids with decrease in temperature. The major fatty acids recorded were oleic acid, linoleic acid, linolenic acid, palmitic acid, stearic acid, myristic acid and pentadecanoic acid. Based on sequence data and, physiological and morphological properties of the strains, we propose a novel species, Rhodotorula svalbardensis and designate strains MLB-I (CCP-II) and CRY-YB-1 (CBS 12863, JCM 19699, JCM 19700, MTCC 10952) as its type strains (Etymology: sval.bar.den'sis. N.L. fem. adj. svalbardensis pertaining to Svalbard). Copyright © 2014 Elsevier Inc. All rights reserved.

Catheter-related bloodstream infection due to Rhodotorula mucilaginosa with normal serum (1→3)-β-D-glucan level.

PubMed

Kitazawa, T; Ishigaki, S; Seo, K; Yoshino, Y; Ota, Y

2018-06-01

Rhodotorula species are environmental basidiomycete yeasts that have emerged as a cause of fungemia in immunocompromised hosts. The insertion of a central venous catheter was identified as a major risk factor for Rhodotorula fungemia. Few cases reports have reported (1→3)-β-D-glucan testing at the onset of Rhodotorula mucilaginosa fungemia. We report a case of catheter-related bloodstream infection due to R. mucilaginosa. Serum β-D-glucan level was normal at the onset of the bloodstream infection. It took 5 days to culture the isolate. The patient's fever persisted after empiric treatment with micafungin, and a switch to oral voriconazole immediately resolved the fungemia. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Endocarditis caused by Rhodotorula infection.

PubMed

Simon, Matthew S; Somersan, Selin; Singh, Harjot K; Hartman, Barry; Wickes, Brian L; Jenkins, Stephen G; Walsh, Thomas J; Schuetz, Audrey N

2014-01-01

Rhodotorula is an emerging opportunistic fungal pathogen that is rarely reported to cause endocarditis. We describe a case involving a patient who developed endocarditis due to Rhodotorula mucilaginosa and Staphylococcus epidermidis, proven by culture and histopathology. The case illustrates the unique diagnostic and therapeutic challenges relevant to Rhodotorula spp.

Endocarditis Caused by Rhodotorula Infection

PubMed Central

Simon, Matthew S.; Somersan, Selin; Singh, Harjot K.; Hartman, Barry; Wickes, Brian L.; Jenkins, Stephen G.; Walsh, Thomas J.

2014-01-01

Rhodotorula is an emerging opportunistic fungal pathogen that is rarely reported to cause endocarditis. We describe a case involving a patient who developed endocarditis due to Rhodotorula mucilaginosa and Staphylococcus epidermidis, proven by culture and histopathology. The case illustrates the unique diagnostic and therapeutic challenges relevant to Rhodotorula spp. PMID:24197888

Biodegradation and detoxification of aliphatic and aromatic hydrocarbons by new yeast strains.

PubMed

Hashem, Mohamed; Alamri, Saad A; Al-Zomyh, Sharefah S A A; Alrumman, Sulaiman A

2018-04-30

Seeking new efficient hydrocarbon-degrading yeast stains was the main goal of this study. Because microorganisms are greatly affected by the environmental factors, the biodegradation potentiality of the microorganisms varies from climatic area to another. This induces research to develop and optimize the endemic organisms in bioremediation technology. In this study, 67 yeast strains were tested for their growth potentiality on both aliphatic and aromatic hydrocarbons. The most efficient six strains were identified using sequence analysis of the variable D1/D2 domain of the large subunit 26S ribosomal DNA. The identity of these strains was confirmed as Yamadazyma mexicana KKUY-0160, Rhodotorula taiwanensis KKUY-0162, Pichia kluyveri KKUY-0163, Rhodotorula ingeniosa KKUY-0170, Candida pseudointermedia KKUY-0192 and Meyerozyma guilliermondii KKUY-0214. These species are approved for their ability to degrade both aliphatic and aromatic hydrocarbons for the first time in this study. Although, all of them were able to utilize and grow on both hydrocarbons, Rhodotorula taiwanensis KKUY-0162 emerged as the best degrader of octane, and Rhodotorula ingeniosa KKUY-170 was the best degrader of pyrene. GC-MS analysis approved the presence of many chemical compounds that could be transitional or secondary metabolites during the utilization of the hydrocarbons. Our results recommend the application of these yeast species on large scale to approve their efficiency in bioremediation of oil-contamination of the environment. Using these yeasts, either individually or in consortia, could offer a practical solution for aquatic or soil contamination with the crude oil and its derivatives in situ. Copyright © 2017 Elsevier Inc. All rights reserved.

Proteomic analysis of a high aluminum tolerant yeast Rhodotorula taiwanensis RS1 in response to aluminum stress.

PubMed

Wang, Chao; Wang, Chang Yi; Zhao, Xue Qiang; Chen, Rong Fu; Lan, Ping; Shen, Ren Fang

2013-10-01

Rhodotorula taiwanensis RS1 is a high-aluminum (Al)-tolerant yeast that can survive in Al concentrations up to 200mM. The mechanisms for the high Al tolerance of R. taiwanensis RS1 are not well understood. To investigate the molecular mechanisms underlying Al tolerance and toxicity in R. taiwanensis RS1, Al toxicity-induced changes in the total soluble protein profile were analyzed using two-dimensional gel electrophoresis (2-DE) coupled with mass spectrometry. A total of 33 differentially expressed proteins responding to Al stress were identified from approximately 850 reproducibly detected proteins. Among them, the abundance of 29 proteins decreased and 4 increased. In the presence of 100mM Al, the abundance of proteins involved in DNA transcription, protein translation, DNA defense, Golgi functions and glucose metabolism was decreased. By contrast, Al treatment led to increased abundance of malate dehydrogenase, which correlated with increased malate dehydrogenase activity and the accumulation of intracellular citrate, suggesting that Al-induced intracellular citrate could play an important role in detoxification of Al in R. taiwanensis RS1. © 2013.

Effect of yeast biomass with high content of carotenoids on erythrocyte deformability, NO production and Na,K-ATPase activity in healthy and LPS treated rats.

PubMed

Radosinska, J; Mezesova, L; Okruhlicova, L; Frimmel, K; Breierova, E; Bartekova, M; Vrbjar, N

2016-11-25

Measurements of red blood cell (RBC) deformability together with estimation of NO-synthase activity and Na,K-ATPase activity were used for characterization of RBC functionality in rats subjected to single dose of Escherichia coli lipopolysaccharides (LPS) at a dose of 1 mg/kg. We hypothesized that LPS might initiate a malfunction of RBC. We also investigated the potential effect of carotenoids (10 mg/kg/day) produced in red yeast biomass of Rhodotorula glutinis on RBC in LPS-challenged rats. LPS significantly reduced the deformability of RBC (by 14%) together with decrease of NO-synthase activity by 20%. Daily supplementation of carotenoids for 10 days attenuated the LPS-induced injury, as observed by 22% increase of RBC deformability and 23% increase of NO-synthase activity. The activity of Na,K-ATPase was also improved probably due to increased number of active enzyme molecules as indicated by 66% enhancement of Vmax value, hence maintaining the activity of erythrocyte Na,K-ATPase to the level even higher as compared with healthy control animals. It may be concluded that administration of yeast biomass with high content of carotenoids resulted in advanced function of erythrocytes as concerns their ability to squeeze through narrow capillaries of the circulation, better intrinsic production of NO and improvement of intracellular homeostasis of sodium.

Isolation and characterization of an acrylamide-degrading yeast Rhodotorula sp. strain MBH23 KCTC 11960BP.

PubMed

Rahim, M B H; Syed, M A; Shukor, M Y

2012-10-01

As well as for chemical and environmental reasons, acrylamide is widely used in many industrial applications. Due to its carcinogenicity and toxicity, its discharge into the environment causes adverse effects on humans and ecology alike. In this study, a novel acrylamide-degrading yeast has been isolated. The isolate was identified as Rhodotorula sp. strain MBH23 using ITS rRNA analysis. The results showed that the best carbon source for growth was glucose at 1.0% (w/v). The optimum acrylamide concentration, being a nitrogen source for cellular growth, was at 500 mg l(-1). The highest tolerable concentration of acrylamide was 1500 mg l(-1) whereas growth was completely inhibited at 2000 mg l(-1). At 500 mg l(-1), the strain MBH completely degraded acrylamide on day 5. Acrylic acid as a metabolite was detected in the media. Strain MBH23 grew well between pH 6.0 and 8.0 and between 27 and 30 °C. Amides such as 2-chloroacetamide, methacrylamide, nicotinamide, acrylamide, acetamide, and propionamide supported growth. Toxic heavy metals such as mercury, chromium, and cadmium inhibited growth on acrylamide. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Endocarditis due to Rhodotorula mucilaginosa in a kidney transplanted patient: case report and review of medical literature.

PubMed

Cabral, Andrea Maria; da Siveira Rioja, Suzimar; Brito-Santos, Fabio; Peres da Silva, Juliana Ribeiro; MacDowell, Maria Luíza; Melhem, Marcia S C; Mattos-Guaraldi, Ana Luíza; Hirata Junior, Raphael; Damasco, Paulo Vieira

2017-11-01

Introduction. Endocarditis caused by yeasts is currently an emerging cause of infective endocarditis and, when accompanied byfever of unknown origin, is more severe since interferes with proper diagnosis and endocarditis treatment. Case presentation. The Rio de Janeiro Infective Endocarditis Study Group reports a case of infectious endocarditis (IE) with negative blood cultures in a 45-year-old white female resident in Rio de Janeiro, Brazil, previously submitted to kidney transplantation. After diagnosis and intervention, the valve culture revealed Rhodotorula mucilaginosa . The clinical aspects and overview of endocarditis caused by Rhodotorula spp. demonstrated that R. muscilaginosa have been isolated from the last IE cases from kidney transplanted patients. Conclusion. Though most of the patients (in literature) recovered well from endocarditis caused by Rhodotorula spp., physicians must be aware for diagnosis of fungemia and fungal treatment in kidney transplanted patients suffering of fever of unknown origin in the modern immunosuppressive treatment.

Endocarditis due to Rhodotorula mucilaginosa in a kidney transplanted patient: case report and review of medical literature

PubMed Central

Cabral, Andrea Maria; da Siveira Rioja, Suzimar; Brito-Santos, Fabio; Peres da Silva, Juliana Ribeiro; MacDowell, Maria Luíza; Melhem, Marcia S. C.; Mattos-Guaraldi, Ana Luíza; Hirata Junior, Raphael

2017-01-01

Introduction. Endocarditis caused by yeasts is currently an emerging cause of infective endocarditis and, when accompanied byfever of unknown origin, is more severe since interferes with proper diagnosis and endocarditis treatment. Case presentation. The Rio de Janeiro Infective Endocarditis Study Group reports a case of infectious endocarditis (IE) with negative blood cultures in a 45-year-old white female resident in Rio de Janeiro, Brazil, previously submitted to kidney transplantation. After diagnosis and intervention, the valve culture revealed Rhodotorula mucilaginosa. The clinical aspects and overview of endocarditis caused by Rhodotorula spp. demonstrated that R. muscilaginosa have been isolated from the last IE cases from kidney transplanted patients. Conclusion. Though most of the patients (in literature) recovered well from endocarditis caused by Rhodotorula spp., physicians must be aware for diagnosis of fungemia and fungal treatment in kidney transplanted patients suffering of fever of unknown origin in the modern immunosuppressive treatment. PMID:29255609

Diversity of yeasts associated with the sea surface microlayer and underlying water along the northern coast of Taiwan.

PubMed

Chang, Chin-Feng; Lee, Ching-Fu; Lin, Kao-Yung; Liu, Shiu-Mei

2016-01-01

Yeast communities inhabiting the sea surface microlayer (SSML) on the northern coast of Taiwan were examined using a cultivation method and compared with those inhabiting the underlying water (UW) at a 50-cm depth. Culturable yeasts were recovered from the SSML and UW samples collected in the morning during 4 field campaigns, and 420 strains were isolated. The 420 isolates were grouped into 43 species using a polyphasic molecular approach, including sequence analysis of the 26S rDNA D1/D2 domain and 5.8S-ITS region. From the SSML samples, 12 genera and 39 species, including 7 new species of Cryptococcus sp. (1), Candida spp. (4), and Rhodotorula spp. (2), were isolated. From the UW samples, 10 genera and 21 species, including one new species of Rhodotorula sp. (1), were isolated. Rhodotorula mucilaginosa was the most abundant species present in the yeast community in SSML (37.6%) and UW (21.6%) samples. Basidiomycetous yeasts (63.6%) and pigmented yeasts (64.5%) comprised the major yeast population. The yeast community in the SSML had a higher species number and abundance than the UW. Moreover, although the majority of yeast community species were from the SSML, individual species distribution in the SSML was unequal. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Improved High-Quality Draft Genome Sequence of the Eurypsychrophile Rhodotorula sp. JG1b, Isolated from Permafrost in the Hyperarid Upper-Elevation McMurdo Dry Valleys, Antarctica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goordial, Jacqueline; Raymond-Bouchard, Isabelle; Riley, Robert

Here, we report the draft genome sequence of Rhodotorula sp. strain JG1b, a yeast that was isolated from ice-cemented permafrost in the upper-elevation McMurdo Dry Valleys, Antarctica. The sequenced genome size is 19.39 Mb, consisting of 156 scaffolds and containing a total of 5,625 predicted genes. This is the first known cold-adapted Rhodotorula sp. sequenced to date.

Improved High-Quality Draft Genome Sequence of the Eurypsychrophile Rhodotorula sp. JG1b, Isolated from Permafrost in the Hyperarid Upper-Elevation McMurdo Dry Valleys, Antarctica

DOE PAGES

Goordial, Jacqueline; Raymond-Bouchard, Isabelle; Riley, Robert; ...

2016-03-17

Here, we report the draft genome sequence of Rhodotorula sp. strain JG1b, a yeast that was isolated from ice-cemented permafrost in the upper-elevation McMurdo Dry Valleys, Antarctica. The sequenced genome size is 19.39 Mb, consisting of 156 scaffolds and containing a total of 5,625 predicted genes. This is the first known cold-adapted Rhodotorula sp. sequenced to date.

Discovery of synthesis and secretion of polyol esters of fatty acids by four basidiomycetous yeast species in the order Sporidiobolales.

PubMed

Garay, Luis A; Sitepu, Irnayuli R; Cajka, Tomas; Fiehn, Oliver; Cathcart, Erin; Fry, Russell W; Kanti, Atit; Joko Nugroho, Agustinus; Faulina, Sarah Asih; Stephanandra, Sira; German, J Bruce; Boundy-Mills, Kyria L

2017-06-01

Polyol esters of fatty acids (PEFA) are amphiphilic glycolipids produced by yeast that could play a role as natural, environmentally friendly biosurfactants. We recently reported discovery of a new PEFA-secreting yeast species, Rhodotorula babjevae, a basidiomycetous yeast to display this behavior, in addition to a few other Rhodotorula yeasts reported on the 1960s. Additional yeast species within the taxonomic order Sporidiobolales were screened for secreted glycolipid production. PEFA production equal or above 1 g L -1 were detected in 19 out of 65 strains of yeast screened, belonging to 6 out of 30 yeast species tested. Four of these species were not previously known to secrete glycolipids. These results significantly increase the number of yeast species known to secrete PEFA, holding promise for expanding knowledge of PEFA synthesis and secretion mechanisms, as well as setting the groundwork towards commercialization.

Peripheral blood and bone marrow cells cultivated in Novy-Mcneal-Nicolle medium for visceral leishmaniosis diagnosis revealed Rhodotorula fungemia in an AIDS patient with lymphoma.

PubMed

Paugam, Andre; Lebuisson, Agathe; Lortholary, Olivier; Baixench, Marie-Therese; Lanternier, Fanny

2013-01-01

Rhodotorula is a ubiquitous yeast that can infect immunocompromised patients. Here, we present the case of a 45-year-old patient with AIDS who developed a Rhodotorula mucilaginosa fungemia. The patient had a past history of visceral leishmaniasis (VL) and was hospitalised to receive chemotherapy for a B-cell lymphoma of the sinonasal cavities. The patient had no fever and no signs of VL. A systematic research for Leishmania by blood and bone marrow cultures was made and he received liposomal amphtotericin B (3 mg/kg in a single dose) to prevent a VL relapse. Rhodotorula fungemia was accidentally detected after 17 days of blood culture using a specific medium for leishmaniasis diagnosis. This long culture incubation time was probably facilitated by amphotericin B treatment. Rhodotorula is an emerging pathogen that may escape detection due its slow growth in culture.

Rhodotorula minuta as onychomycosis agent in a Chinese patient: first report and literature review.

PubMed

Zhou, Jie; Chen, Min; Chen, Hongduo; Pan, Weihua; Liao, Wanqing

2014-03-01

Onychomycosis is a common superficial fungal infection, which usually caused by dermatophytes, yeast and non-dermatophytic moulds. Recently, we isolated a Rhodotorula minuta isolate from a 15-year-old immunocompetent girl student in Hangzhou (China) that was identified using microscopy, culture morphology, histological diagnosis, API 20C AUX Yeast Identification Kit and sequencing of the Internal Transcribed Spacer region. In vitro, antifungal susceptibility tests showed that this yeast isolate was susceptible to low concentrations of amphotericin B, itraconazole, voriconazole and 5-flvoriconaz but that it appeared to be dose-dependent susceptible to fluconazole(MIC = 16 μg/ml). Furthermore, the effective result of therapy with itraconazole against R. minuta was consistent with that of susceptibility tests. © 2013 Blackwell Verlag GmbH.

Isolation of oligotrophic yeasts from supraglacial environments of different altitude on the Gulkana Glacier (Alaska).

PubMed

Uetake, Jun; Yoshimura, Yoshitaka; Nagatsuka, Naoko; Kanda, Hiroshi

2012-11-01

Psychrophilic yeasts have been isolated from supra- and subglacial ice at many sites worldwide. To understand the ecology of psychrophilic yeasts on glaciers, we focused on their adaptation to wide range of nutrient concentrations and their distribution with altitude on the Gulkana Glacier in Alaska. We found various culturable psychrophilic yeasts on the ice surfaces of the glacier, and 11 species were isolated with incubation at 4 °C in four different dilutions of agar medium. Some of our isolated species (Rhodotorula psychrophenolica, Rhodotorula aff. psychrophenolica, Rhodotorula glacialis, and Basidiomycota sp. 1) can grow on the low dissolved organic matter (DOC) concentrations medium (7.6 mg L(-1)) which is close to the typical level of supraglacial melt water, suggesting that these species can inhabit in any supraglacial meltwater. Otherwise, most of other species were isolated only from higher DOC concentration medium (183 mg L(-1) -18.3 g L(-1)), suggesting that these are inhabitant around the cryoconite, because DOC concentrations in melted surface-ice contained cryoconite is much higher than in melted water. Similarity of altitudinal distribution between culturable yeast and algal biomass suggests that the ecological role played by the cold-adapted yeasts is as organic matter decomposers and nutrient cyclers in glacier ecosystem. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Yeast microbiota of natural cavities of manatees (Trichechus inunguis and Trichechus manatus) in Brazil and its relevance for animal health and management in captivity.

PubMed

Sidrim, José Júlio Costa; Carvalho, Vitor Luz; Castelo-Branco, Débora de Souza Collares Maia; Brilhante, Raimunda Sâmia Nogueira; Bandeira, Tereza de Jesus Pinheiro Gomes; Cordeiro, Rossana de Aguiar; Guedes, Gláucia Morgana de Melo; Barbosa, Giovanna Riello; Lazzarini, Stella Maris; Oliveira, Daniella Carvalho Ribeiro; de Meirelles, Ana Carolina Oliveira; Attademo, Fernanda Löffler Niemeyer; Freire, Augusto Carlos da Bôaviagem; Moreira, José Luciano Bezerra; Monteiro, André Jalles; Rocha, Marcos Fábio Gadelha

2015-10-01

The aim of this study was to characterize the yeast microbiota of natural cavities of manatees kept in captivity in Brazil. Sterile swabs from the oral cavity, nostrils, genital opening, and rectum of 50 Trichechus inunguis and 26 Trichechus manatus were collected. The samples were plated on Sabouraud agar with chloramphenicol and incubated at 25 °C for 5 days. The yeasts isolated were phenotypically identified by biochemical and micromorphological tests. Overall, 141 strains were isolated, of which 112 were from T. inunguis (Candida albicans, Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, Candida guilliermondii, Candida pelliculosa, Candida tropicalis, Candida glabrata, Candida famata, Candida krusei, Candida norvegensis, Candida ciferri, Trichosporon sp., Rhodotorula sp., Cryptococcus laurentii) and 29 were from T. manatus (C. albicans, C. tropicalis, C. famata, C. guilliermondii, C. krusei, Rhodotorula sp., Rhodotorula mucilaginosa, Rhodotorula minuta, Trichosporon sp.). This was the first systematic study to investigate the importance of yeasts as components of the microbiota of sirenians, demonstrating the presence of potentially pathogenic species, which highlights the importance of maintaining adequate artificial conditions for the health of captive manatees.

Possible role of Rhodotorula sp. in the formation of jarosite in the AMD environment of Muskau Arch, Poland

NASA Astrophysics Data System (ADS)

Jakus, Natalia; Chlebicki, Andrzej; Bożęcki, Piotr; Manecki, Maciej

2016-04-01

The Muskau Arch is situated in the west of Poland and in the east of Germany. This region is a belt formed by push and frontal moraines during the Middle-Polish (Riss) glaciation, especially during the Wartanian glaciation. The occurrence of glacier caused folding and forming the glacitectonic type of lignit deposits which were mined for over 150 years. Both open pit and underground mining methods has exposed metal sulfides (mainly pyrite) to air and water causing bio-oxidation. Due to this process the acidity of many reservoirs have increased significantly (pH values between 2 and 4). As a consequence of changes in the environment, new mineral phases precipitated from highly acid waters rich in, among others, various forms of Fe and S. Precipitation of ochreous minerals such as schwertmannite, goethite and jarosite was partly catalyzed by many various acidophilic and acid-tolerant microorganisms: bacteria, archaea and probably yeasts. Jarosite KFe33+(OH)6(SO4)2 can be precipitated both in abiotic conditions and as a by-product of the activity of living organisms. The example of biomineralization induced by fungi Purpureocillium lilacinum in similar AMD environment of Rio Tinto is reported (Oggerin et al, 2014). Recently, jarosite is also considered as a possible biosignature of life on Mars. The assessment of microbial participation in formation of jarosite is an elementary step in geomicrobiological and astrobiological research. Isolated by us Rhodotorula sp. is an unicellular pigmented yeast. Fungi from the genus Rhodotorula F.C. Harrison belong to Sporidiobolalas part of phylum Basidiomycota. They are common environmental inhabitants. Some species, known from Rio Tinto, can live in extreme acidic soils at pH of about 2 (Lopez-Archila et al, 2004). For the first time, authors isolated strain Rhodotorula sp. from surface precipitates in Ł ęknica region (Muskau Arch). This ochreous precipitate contains jarosite. The yeast might be an important factor in indirect

Yeast and Macroinvertebrate Communities Associated with Leaf Litter Decomposition in a Second Order Stream

NASA Astrophysics Data System (ADS)

Sampaio, Ana; Cortes, Rui; Leão, Cecília

2004-11-01

The composition of yeast and macroinvertebrate communities was studied on black alder, blue gum eucalyptus and English oak leaves decaying in a stream during a six-month period. ANOVA analysis showed significantly different values (p < 0.0001) of yeast and macroinvertebrate densities among the three leaf litters. Some yeast species such as Cryptococcus albidus (Saito), C. laurentii (Kufferath), Rhodothorula glutinis (Fresenius), R. colostri (Castelli), and Debaryomyces hansenii (Lodder and Kreger-van Rij) were present in all litter types. Other yeasts were restricted to a specific type of litter. Macroinvertebrates were dominated by collectors-gatherers on oak and eucalyptus leaves. Shredders reached highest densities in alder leaves. (

Risk of Fungemia Due to Rhodotorula and Antifungal Susceptibility Testing of Rhodotorula Isolates

PubMed Central

Zaas, Aimee K.; Boyce, Molly; Schell, Wiley; Lodge, Barbara Alexander; Miller, Jackie L.; Perfect, John R.

2003-01-01

Rhodotorula infections occur among patients with immunosuppression and/or central venous catheters. Using standardized methods (NCCLS M27-A), we determined the antifungal susceptibilities of 10 Rhodotorula bloodstream infection isolates. Patient information was collected for clinical correlation. The MICs of amphotericin B and posaconazole were the lowest, and the MICs of triazoles and echinocandins were higher than those of other antifungal agents. PMID:14605170

Cloning and characterization of iron-superoxide dismutase in Antarctic yeast strain Rhodotorula mucilaginosa AN5.

PubMed

Kan, Guangfeng; Wen, Hua; Wang, Xiaofei; Zhou, Ting; Shi, Cuijuan

2017-08-01

A novel superoxide dismutase gene from Antarctic yeast Rhodotorula mucilaginosa AN5 was cloned, sequenced, and then expressed in Escherichia coli. The R. mucilaginosa AN5 SOD (RmFeSOD) gene was 639 bp open reading frame in length, which encoded a protein of 212 amino acids with a deduced molecular mass of 23.5 kDa and a pI of 7.89. RmFeSOD was identified as iron SOD type with a natural status of homodimer. The recombinant RmFeSOD showed good pH stability in the pH 1.0-9.0 after 1 h incubation. Meanwhile, it was found to behave relatively high thermostability, and maintained more than 80% activity at 50 °C for 1 h. By addition of 1 mM metal ions, the enzyme activity increased by Zn 2+ , Cu 2+ , Mn 2+ , and Fe 3+ , and inhibited only by Mg 2+ . RmFeSOD showed relatively low tolerance to some compounds, such as PMSF, SDS, Tween-80, Triton X-100, DMSO, β-ME, and urea. However, DTT showed no inhibition to enzyme activity. Using copper stress experiment, the RmFeSOD recombinant E. coli exhibited better growth than non-recombinant bacteria, which revealed that RmFeSOD might play an important role in the adaptability of heavy metals. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improvement of carotenoid-synthesizing yeast Rhodotorula rubra by chemical mutagenesis.

PubMed

Frengova, Ginka I; Simova, Emilina D; Beshkova, Dora M

2004-01-01

A mutant Rhodotorula rubra with enhanced carotenoid-synthesizing activity for synthesizing total carotenoids and beta-carotene was obtained by N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. When co-cultivated with yogurt starter bacteria (Lactobacillus bulgaricus + Streptococcus thermophilus) in whey ultrafiltrate it produced 15.7 mg total carotenoids l(-1) culture fluid or 946 microg total carotenoids g(-1) dry cells of which 71% was beta-carotene. Grown as a monoculture in glucose substrate, the mutant shown 1.4 times lower carotenoid-synthesizing activity, and the relative share of beta-carotene in the total carotenoids was lower (63%). The individual pigments torulene and torularhodin were identified, whose mass fractions were (29% and 7%) and (24% and 4%), respectively, for the mutant grown as a monoculture and as a mixed culture with the yogurt bacteria.

Evidence for propagation of cold-adapted yeast in an ice core from a Siberian Altai glacier

NASA Astrophysics Data System (ADS)

Uetake, Jun; Kohshima, Shiro; Nakazawa, Fumio; Takeuchi, Nozomu; Fujita, Koji; Miyake, Takayuki; Narita, Hideki; Aizen, Vladimir; Nakawo, Masayoshi

2011-03-01

Cold environments, including glacier ice and snow, are known habitats for cold-adapted microorganisms. We investigated the potential for cold-adapted yeast to have propagated in the snow of the high-altitude Belukha glacier. We detected the presence of highly concentrated yeast (over 104 cells mL-1) in samples of both an ice core and firn snow. Increasing yeast cell concentrations in the same snow layer from July 2002 to July 2003 suggests that the yeast cells propagated in the glacier snow. A cold-adapted Rhodotorula sp. was isolated from the snow layer and found to be related to psychrophilic yeast previously found in other glacial environments (based on the D1/D2 26S rRNA domains). 26S rRNA clonal analysis directly amplified from meltwater within the ice core also revealed the presence of genus Rhodotorula. Analyses of the ice core showed that all peaks in yeast concentration corresponded to the peaks in indices of surface melting. These results support the hypothesis that occasional surface melting in an accumulation area is one of the major factors influencing cold-adapted yeast propagation.

Statistical optimisation of cell growth and carotenoid production by rhodotorula mucilaginosa

PubMed Central

Maldonade, Iriani R.; Rodriguez-Amaya, Delia B.; Scamparini, Adilma R. P.

2012-01-01

Sequential statistical methods were used to maximise carotenoid production by a strain of Rhodotorula mucilaginosa, isolated from the Brazilian ecosystem. Initially, a factorial 25–1 experimental design was used, and the variables were pH and the levels of glucose, yeast extract, MgSO4.7H2O and KH2PO4. The nitrogen source (yeast extract) was the most important variable in enhancing carotenoid production; MgSO4.7H2O and KH2PO4 had a negative influence. The initial pH had no significant effect on carotenoid and cell productions. We further investigated the effects of glucose and yeast extract effects, using a second-order central composite design (CCD) to optimise carotenoid production, which was adequately approximated with a full quadratic equation obtained from a two-factor-2-level design. The analysis of quadratic surfaces showed that after 5 days of cultivation at 25 °C, the maximum carotenoid concentration (745 µg l-1) was obtained with 15 g l-1 of yeast extract and 20 g l-1 of glucose. The maximum carotenoid production (152 µg g-1) was obtained with 5 g l-1 yeast extract and 10 g l-1 glucose. Carotenoid formation was more sensitive to changes in yeast extract concentration than to changes in glucose concentration. Maximum cell production was achieved with 15–17 g l-1 of yeast extract and 15–20 g l-1 of glucose. PMID:24031809

Aeration controls the reduction and methylation of tellurium by the aerobic, tellurite-resistant marine yeast Rhodotorula mucilaginosa.

PubMed

Ollivier, Patrick R L; Bahrou, Andrew S; Church, Thomas M; Hanson, Thomas E

2011-07-01

We previously described a marine, tellurite-resistant strain of the yeast Rhodotorula mucilaginosa that both precipitates intracellular Te0 and volatilizes methylated Te compounds when grown in the presence of the oxyanion tellurite. The uses of microbes as a "green" route for the production of Te0-containing nanostructures and for the remediation of Te-oxyanion wastes have great potential, and so a more thorough understanding of this process is required. Here, Te precipitation and volatilization catalyzed by R. mucilaginosa were examined in continuously aerated and sealed (low oxygen concentration) batch cultures. Continuous aeration was found to strongly promote Te volatilization while inhibiting Te0 precipitation. This differs from the results in sealed batch cultures, for which tellurite reduction to Te0 was found to be very efficient. We show also that volatile Te species may be degraded rapidly in medium and converted to the particulate form by biological activity. Further experiments revealed that Te0 precipitates produced by R. mucilaginosa can be further transformed to volatile and dissolved Te species. However, it was not clearly determined whether Te0 is a required intermediate for Te volatilization. Based on these results, we conclude that low oxygen concentrations will be the most efficient for production of Te0 nanoparticles while limiting the production of toxic volatile Te species, although the production of these compounds may never be completely eliminated.

Aeration Controls the Reduction and Methylation of Tellurium by the Aerobic, Tellurite-Resistant Marine Yeast Rhodotorula mucilaginosa▿

PubMed Central

Ollivier, Patrick R. L.; Bahrou, Andrew S.; Church, Thomas M.; Hanson, Thomas E.

2011-01-01

We previously described a marine, tellurite-resistant strain of the yeast Rhodotorula mucilaginosa that both precipitates intracellular Te(0) and volatilizes methylated Te compounds when grown in the presence of the oxyanion tellurite. The uses of microbes as a “green” route for the production of Te(0)-containing nanostructures and for the remediation of Te-oxyanion wastes have great potential, and so a more thorough understanding of this process is required. Here, Te precipitation and volatilization catalyzed by R. mucilaginosa were examined in continuously aerated and sealed (low oxygen concentration) batch cultures. Continuous aeration was found to strongly promote Te volatilization while inhibiting Te(0) precipitation. This differs from the results in sealed batch cultures, for which tellurite reduction to Te(0) was found to be very efficient. We show also that volatile Te species may be degraded rapidly in medium and converted to the particulate form by biological activity. Further experiments revealed that Te(0) precipitates produced by R. mucilaginosa can be further transformed to volatile and dissolved Te species. However, it was not clearly determined whether Te(0) is a required intermediate for Te volatilization. Based on these results, we conclude that low oxygen concentrations will be the most efficient for production of Te(0) nanoparticles while limiting the production of toxic volatile Te species, although the production of these compounds may never be completely eliminated. PMID:21602387

Utilization of hydrothermally pretreated wheat straw for production of bioethanol and carotene-enriched biomass.

PubMed

Petrik, Siniša; Kádár, Zsófia; Márová, Ivana

2013-04-01

In this work hydrothermally pretreated wheat straw was used for production of bioethanol by Saccharomyces cerevisiae and carotene-enriched biomass by red yeasts Rhodotorula glutinis, Cystofilobasidium capitatum and Sporobolomyces roseus. To evaluate the convertibility of pretreated wheat straw into ethanol, simultaneous saccharification and fermentation of S. cerevisiae was performed under semi-anaerobic conditions. The highest ethanol production efficiency of 65-66% was obtained following pretreatment at 200°C without the catalytic action of acetic acid, and at 195 and 200°C respectively in the presence of catalyst. Red yeast strain S. roseus produced 1.73-2.22 mg g(-1) of ergosterol on the filter cake, 1.15-4.17 mg g(-1) of ergosterol and 1.23-1.56 mg g(-1) of β-carotene on pretreated wheat straw hydrolysates and also the highest amount of carotenoids and ergosterol on untreated wheat straw (1.70 and 4.17 mg g(-1), respectively). Copyright © 2013 Elsevier Ltd. All rights reserved.

Separation, hydrolysis and fermentation of pyrolytic sugars to produce ethanol and lipids.

PubMed

Lian, Jieni; Chen, Shulin; Zhou, Shuai; Wang, Zhouhong; O'Fallon, James; Li, Chun-Zhu; Garcia-Perez, Manuel

2010-12-01

This paper describes a new scheme to convert anhydrosugars found in pyrolysis oils into ethanol and lipids. Pyrolytic sugars were separated from phenols by solvent extraction and were hydrolyzed into glucose using sulfuric acid as a catalyst. Toxicological studies showed that phenols and acids were the main species inhibiting growth of the yeast Saccharomyces cerevisiae. The sulfuric acids, and carboxylic acids from the bio-oils, were neutralized with Ba(OH)(2). The phase rich in sugar was further detoxified with activated carbon. The resulting aqueous phase rich in glucose was fermented with three different yeasts: S. cerevisiae to produce ethanol, and Cryptococcus curvatus and Rhodotorula glutinis to produce lipids. Yields as high as 0.473 g ethanol/g glucose and 0.167 g lipids/g sugar (0.266 g ethanol equivalent/g sugar), were obtained. These results confirm that pyrolytic sugar fermentation to produce ethanol is more efficient than for lipid production. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Similar Mutation Rates but Highly Diverse Mutation Spectra in Ascomycete and Basidiomycete Yeasts.

PubMed

Long, Hongan; Behringer, Megan G; Williams, Emily; Te, Ronald; Lynch, Michael

2016-12-01

Yeast species are extremely diverse and not monophyletic. Because the majority of yeast research focuses on ascomycetes, the mutational determinants of genetic diversity across yeast species are not well understood. By combining mutation-accumulation techniques with whole-genome sequencing, we resolved the genomic mutation rate and spectrum of the oleaginous (oil-producing) ‘red yeast’ Rhodotorula toruloides, the first such study in the fungal phylum Basidiomycota. We find that the mutation spectrum is quite different from what has been observed in all other studied unicellular eukaryotes, but similar to that in most bacteria—a predominance of transitions relative to transversions. Rhodotorula toruloides has a significantly higher A:T→G:C transition rate—possibly elevated by the abundant flanking G/C nucleotides in the GC-rich genome, as well as a much lower G:C→T:A transversion rate. In spite of these striking differences, there are substantial consistencies between R. toruloides and the ascomycete model yeasts: a spontaneous base-substitution mutation rate of 1.90 × 10 −10 per site per cell division as well as an elevated mutation rate at non-methylated 5'CpG3' sites. These results imply the evolution of variable mutation spectra in the face of similar mutation rates in yeasts.

Femoral Prosthesis Infection by Rhodotorula mucilaginosa▿

PubMed Central

Savini, Vincenzo; Sozio, Federica; Catavitello, Chiara; Talia, Marzia; Manna, Assunta; Febbo, Fabio; Balbinot, Andrea; Di Bonaventura, Giovanni; Piccolomini, Raffaele; Parruti, Giustino; D'Antonio, Domenico

2008-01-01

This case report is a case history of a femoral prosthesis infection caused by Rhodotorula mucilaginosa in a human immunodeficiency virus patient. Though the pathogenicity of this organism for bone tissue has been previously reported, this is the first reported case of an orthopedic prosthesis infection by this species of the genus Rhodotorula. PMID:18753353

Red yeasts and carotenoid production: outlining a future for non-conventional yeasts of biotechnological interest.

PubMed

Mannazzu, Ilaria; Landolfo, Sara; Lopes da Silva, Teresa; Buzzini, Pietro

2015-11-01

Carotenoids are one of the most common classes of pigments that occur in nature. Due to their biological properties, they are widely used in phytomedicine and in the chemical, pharmaceutical, cosmetic, food and feed industries. Accordingly, their global market is continuously growing, and it is expected to reach about US$1.4 billion in 2018. Carotenoids can be easily produced by chemical synthesis, although their biotechnological production is rapidly becoming an appealing alternative to the chemical route, partly due to consumer concerns against synthetic pigments. Among the yeasts, and apart from the pigmented species Phaffia rhodozyma (and its teleomorph Xanthophyllomyces dendrorhous), a handful of species of the genera Rhodosporidium, Rhodotorula, Sporobolomyces and Sporidiobolus are well known carotenoid producers. These are known as 'red yeasts', and their ability to synthesize mixtures of carotenoids from low-cost carbon sources has been broadly studied recently. Here, in agreement with the renewed interest in microbial carotenoids, the recent literature is reviewed regarding the taxonomy of the genera Rhodosporidium, Rhodotorula, Sporobolomyces and Sporidiobolus, the stress factors that influence their carotenogenesis, and the most advanced analytical tools for evaluation of carotenoid production. Moreover, a synopsis of the molecular and "-omic" tools available for elucidation of the metabolic pathways of the microbial carotenoids is reported.

Lipids, hemoproteins and carotenoids in alive Rhodotorula mucilaginosa cells under pesticide decomposition - Raman imaging study.

PubMed

Pacia, Marta Z; Pukalski, Jan; Turnau, Katarzyna; Baranska, Malgorzata; Kaczor, Agnieszka

2016-12-01

Various species of yeasts are gaining attention as producers of nutraceuticals and biofuels and due to their capacity to biodegrade chemical waste. Rhodotorula mucilaginosa is one of the most oleaginous species of yeast, an efficient de novo carotenoid producer and was reported to be capable of decomposing of organic pesticides. In this work we studied the influence of a toxic pesticide, diazinone, on production of storage (lipids) and protective (carotenoids, hemoproteins) compounds by Rh. mucilaginosa alive cells with the help of Raman imaging. It occurred that the yeast in non-oleaginous phase and aerobic environment was rich in carotenoids and their level increased significantly under incubation with diazinone, while anaerobic environment resulted in production of both carotenoids and hemoproteins and the level of the latter decreased under the influence of the pesticide. For yeasts in oleaginous phase, it was concluded that lipid production (via triggering of NAD + accumulation and increase of the NO level) resulted in nitrosative stress leading to flavohemoprotein synthesis and was associated with the increase of the mitochondrial activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Occurrence of killer yeasts in leaf-cutting ant nests.

PubMed

Carreiro, S C; Pagnocca, F C; Bacci, M; Bueno, O C; Hebling, M J A; Middelhoven, W J

2002-01-01

Killer activity was screened in 99 yeast strains isolated from the nests of the leaf-cutting ant Atta sexdens against 6 standard sensitive strains, as well as against each other. Among this yeast community killer activity was widespread since 77 strains (78%) were able to kill or inhibit the growth of at least one standard strain or nest strain. Toxin production was observed in representatives of all the studied genera including Aureobasidium, Rhodotorula, Tremella and Trichosporon, whose killer activity has not yet been described.

Rhodotorula fungemia: two cases and a brief review.

PubMed

Duggal, Shalini; Jain, Hemant; Tyagi, Amit; Sharma, Anuradha; Chugh, T D

2011-11-01

Rhodotorula is emerging as an important cause of nosocomial and opportunistic infections. We present two cases of Rhodotorula mucilaginosa fungemia diagnosed over a period of 3 months at our hospital. The first case was of a pre-term neonate in the neonatal ICU who presented with respiratory failure and sepsis. The second involved an adult female who had been injured in a road traffic accident requiring an operation for a hematoma and was later shifted to the medical ICU. For a new hospital like ours, finding two cases of Rhodotorula fungemia within a span of 3 months prompted us to describe them in this report. These cases emphasize the emerging importance of Rhodotorula mucilaginosa as a pathogen and the importance of identification and MIC testing for all fungal isolates recovered from the blood stream.

Rhodotorula Keratitis: A Rarely Encountered Ocular Pathogen

PubMed Central

Giovannini, Joseph; Lee, Rick; Zhang, Sean X.; Jun, Albert S.; Bower, Kraig S.

2014-01-01

Purpose To describe a case of fungal keratitis involving an atypical organism with confirmatory in vivo confocal microscopy and to review the literature on Rhodotorula keratitis. Methods Case report and review of the medical literature. Results A 22-year-old college student was struck in the left eye with a tree branch and subsequently developed pain, redness and photophobia. Upon presentation, visual acuity was 20/200 and there was a large epithelial defect with diffuse stromal inflammation involving the anterior one-third of the cornea. Cultures of the infiltrate were performed for bacterial, viral and fungal organisms that resulted in a positive culture for Rhodotorula mucilaginosa. Fungal elements were confirmed in vivo by confocal microscopy. The patient was treated with voriconazole initially and had amphotericin added once Rhodotorula infection was confirmed. The patient responded well clinically, and one month after therapy was initiated, the corneal infiltrate had resolved leaving mild anterior stromal haze. Upon completion of therapy at three months, the patient was asymptomatic, had a clear cornea and had a best corrected visual acuity of 20/20 in the involved eye. There was no measurable change in his manifest refraction. Conclusions Prior cases of Rhodotorula keratitis most often required surgical intervention and were associated with poor outcomes. This case shows that Rhodotorula keratitis can be successfully treated with topical antifungal agents if diagnosed early and appropriate treatment is initiated promptly. We report the first case of Rhodotorula keratitis confirmed by in vivo confocal microscopy. This is also the first description of pseudomycelium formation that has not been previously described in vivo, a morphological structure that this organism rarely demonstrates. Finally, this case shows that confocal microscopy may aid in the early diagnosis and management of fungal keratitis involving this rare but potentially damaging organism. PMID

Prospects for Fungal Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome Sequence of Rhodotorula taiwanensis MD1149.

PubMed

Tkavc, Rok; Matrosova, Vera Y; Grichenko, Olga E; Gostinčar, Cene; Volpe, Robert P; Klimenkova, Polina; Gaidamakova, Elena K; Zhou, Carol E; Stewart, Benjamin J; Lyman, Mathew G; Malfatti, Stephanie A; Rubinfeld, Bonnee; Courtot, Melanie; Singh, Jatinder; Dalgard, Clifton L; Hamilton, Theron; Frey, Kenneth G; Gunde-Cimerman, Nina; Dugan, Lawrence; Daly, Michael J

2017-01-01

Highly concentrated radionuclide waste produced during the Cold War era is stored at US Department of Energy (DOE) production sites. This radioactive waste was often highly acidic and mixed with heavy metals, and has been leaking into the environment since the 1950s. Because of the danger and expense of cleanup of such radioactive sites by physicochemical processes, in situ bioremediation methods are being developed for cleanup of contaminated ground and groundwater. To date, the most developed microbial treatment proposed for high-level radioactive sites employs the radiation-resistant bacterium Deinococcus radiodurans . However, the use of Deinococcus spp. and other bacteria is limited by their sensitivity to low pH. We report the characterization of 27 diverse environmental yeasts for their resistance to ionizing radiation (chronic and acute), heavy metals, pH minima, temperature maxima and optima, and their ability to form biofilms. Remarkably, many yeasts are extremely resistant to ionizing radiation and heavy metals. They also excrete carboxylic acids and are exceptionally tolerant to low pH. A special focus is placed on Rhodotorula taiwanensis MD1149, which was the most resistant to acid and gamma radiation. MD1149 is capable of growing under 66 Gy/h at pH 2.3 and in the presence of high concentrations of mercury and chromium compounds, and forming biofilms under high-level chronic radiation and low pH. We present the whole genome sequence and annotation of R. taiwanensis strain MD1149, with a comparison to other Rhodotorula species. This survey elevates yeasts to the frontier of biology's most radiation-resistant representatives, presenting a strong rationale for a role of fungi in bioremediation of acidic radioactive waste sites.

Prospects for Fungal Bioremediation of Acidic Radioactive Waste Sites: Characterization and Genome Sequence of Rhodotorula taiwanensis MD1149

PubMed Central

Tkavc, Rok; Matrosova, Vera Y.; Grichenko, Olga E.; Gostinčar, Cene; Volpe, Robert P.; Klimenkova, Polina; Gaidamakova, Elena K.; Zhou, Carol E.; Stewart, Benjamin J.; Lyman, Mathew G.; Malfatti, Stephanie A.; Rubinfeld, Bonnee; Courtot, Melanie; Singh, Jatinder; Dalgard, Clifton L.; Hamilton, Theron; Frey, Kenneth G.; Gunde-Cimerman, Nina; Dugan, Lawrence; Daly, Michael J.

2018-01-01

Highly concentrated radionuclide waste produced during the Cold War era is stored at US Department of Energy (DOE) production sites. This radioactive waste was often highly acidic and mixed with heavy metals, and has been leaking into the environment since the 1950s. Because of the danger and expense of cleanup of such radioactive sites by physicochemical processes, in situ bioremediation methods are being developed for cleanup of contaminated ground and groundwater. To date, the most developed microbial treatment proposed for high-level radioactive sites employs the radiation-resistant bacterium Deinococcus radiodurans. However, the use of Deinococcus spp. and other bacteria is limited by their sensitivity to low pH. We report the characterization of 27 diverse environmental yeasts for their resistance to ionizing radiation (chronic and acute), heavy metals, pH minima, temperature maxima and optima, and their ability to form biofilms. Remarkably, many yeasts are extremely resistant to ionizing radiation and heavy metals. They also excrete carboxylic acids and are exceptionally tolerant to low pH. A special focus is placed on Rhodotorula taiwanensis MD1149, which was the most resistant to acid and gamma radiation. MD1149 is capable of growing under 66 Gy/h at pH 2.3 and in the presence of high concentrations of mercury and chromium compounds, and forming biofilms under high-level chronic radiation and low pH. We present the whole genome sequence and annotation of R. taiwanensis strain MD1149, with a comparison to other Rhodotorula species. This survey elevates yeasts to the frontier of biology's most radiation-resistant representatives, presenting a strong rationale for a role of fungi in bioremediation of acidic radioactive waste sites. PMID:29375494

A new pullulan-producing yeast and medium optimization for its exopolysaccharide production

NASA Astrophysics Data System (ADS)

Zhao, Shuangzhi; Chi, Zhenming

2003-04-01

Yeast strain Y68 producing high level of pullulan was isolated from the phyton collected in Toulouse, France. This strain was identified to be Rhodotorula bacarum by BIOLOG analysis. This is the first report that pullulan was produced by Rhodotorula bacarum. The optimal medium (g L-1) for pullulan production by this strain was 80 glucose, 20 soybean cake hydrolysate, 5 K2HPO4, 1 NaCl, 0.2 MgSO4·7H2O, 0.6 (NH4)2SO4, pH 7.0. Under this condition, 54 gL-1 pullulan was produced within 60 h at 30°C. Pullulan is a better starting material for producing marine prodrugs.

[Invasive yeast infections in neutropenic patients].

PubMed

Ruiz Camps, Isabel; Jarque, Isidro

2016-01-01

Invasive fungal diseases caused by yeasts still play an important role in the morbidity and mortality in neutropenic patients with haematological malignancies. Although the overall incidence of invasive candidiasis has decreased due to widespread use of antifungal prophylaxis, the incidence of non-Candida albicans Candida species is increasing compared with that of C.albicans, and mortality of invasive candidiasis continues to be high. In addition, there has been an increase in invasive infections caused by an array of uncommon yeasts, including species of the genus Malassezia, Rhodotorula, Trichosporon and Saprochaete, characterised by their resistance to echinocandins and poor prognosis. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

Phylogenetic classification of yeasts and related taxa within Pucciniomycotina.

PubMed

Wang, Q-M; Yurkov, A M; Göker, M; Lumbsch, H T; Leavitt, S D; Groenewald, M; Theelen, B; Liu, X-Z; Boekhout, T; Bai, F-Y

2015-06-01

Most small genera containing yeast species in the Pucciniomycotina (Basidiomycota, Fungi) are monophyletic, whereas larger genera including Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces are polyphyletic. With the implementation of the "One Fungus = One Name" nomenclatural principle these polyphyletic genera were revised. Nine genera, namely Bannoa, Cystobasidiopsis, Colacogloea, Kondoa, Erythrobasidium, Rhodotorula, Sporobolomyces, Sakaguchia and Sterigmatomyces, were emended to include anamorphic and teleomorphic species based on the results obtained by a multi-gene phylogenetic analysis, phylogenetic network analyses, branch length-based methods, as well as morphological, physiological and biochemical comparisons. A new class Spiculogloeomycetes is proposed to accommodate the order Spiculogloeales. The new families Buckleyzymaceae with Buckleyzyma gen. nov., Chrysozymaceae with Chrysozyma gen. nov., Microsporomycetaceae with Microsporomyces gen. nov., Ruineniaceae with Ruinenia gen. nov., Symmetrosporaceae with Symmetrospora gen. nov., Colacogloeaceae and Sakaguchiaceae are proposed. The new genera Bannozyma, Buckleyzyma, Fellozyma, Hamamotoa, Hasegawazyma, Jianyunia, Rhodosporidiobolus, Oberwinklerozyma, Phenoliferia, Pseudobensingtonia, Pseudohyphozyma, Sampaiozyma, Slooffia, Spencerozyma, Trigonosporomyces, Udeniozyma, Vonarxula, Yamadamyces and Yunzhangia are proposed to accommodate species segregated from the genera Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces. Ballistosporomyces is emended and reintroduced to include three Sporobolomyces species of the sasicola clade. A total of 111 new combinations are proposed in this study.

Pilot-scale production and liquid formulation of Rhodotorula minuta, a potential biocontrol agent of mango anthracnose.

PubMed

Patiño-Vera, M; Jiménez, B; Balderas, K; Ortiz, M; Allende, R; Carrillo, A; Galindo, E

2005-01-01

To develop a pilot-plant fermentation process for the production of the yeast Rhodotorula minuta, to be used as a biocontrol agent of mango anthracnose, using a low-cost culture medium. To develop a stable liquid formulation that preserve high viability of the yeast stored at 4 degrees C. Keeping constant the volumetric power input, a fermentation process was scaled-up from shake flasks to a 100 l bioreactor. Preharvest applications of the yeast resulted in postharvest anthracnose severity equal or lower than that observed with a chemical fungicide. Glycerol was added to the formulation as water activity reducer and xanthan gum as a viscosity-enhancing agent. Yeast initial concentration of 10(10) CFU ml(-1) resulted in 4-5 orders of magnitude decrease after 1 month of storage at 4 degrees C, whereas when it was formulated at 10(9) CFU ml(-1), the decrease was of two orders of magnitude in 6 months. The fermentation process was successfully scaled-up using a low-cost culture medium. Postharvest anthracnose severity could be considerably reduced using this yeast. Formulating the yeast at 10(9) CFU ml(-1) and adding glycerol (20%) and xanthan (5 g l(-1)) avoided both contamination and yeast sedimentation and it was able to preserve up to 10(7) CFU ml(-1) after 6 months at 4 degrees C. The yeast R. minuta is reported as a novel antagonistic micro-organism against the pathogen Colletotrichum gloeosporioides. Pilot plant production of this yeast allowed us to conduct field tests in commercial orchards during three harvest seasons. Yeast suspensions applied to mango trees reduced the fruit anthracnose severity in levels similar or better than chemical fungicides.

Effects of Cd, Pb, Zn, Cu-resistant endophytic Enterobacter sr CBSB1 and Rhodotorula sp. CBSB79 on the growth and phytoextraction of Brassica plants in multimetal contaminated soils.

PubMed

Wang, Wenfeng; Deng, Zujun; Tan, Hongming; Cao, Lixiang

2013-01-01

To survey the effects of endophytic Enterobacter sp. CBSB1 and Rhodotorula sp. CBSB79 resistant to Cd2+, Pb2+, Zn2+, and Cu2+ on the growth and phytoextraction of Brassica, the endophytes were isolated by surface- sterilized methods and characterized. The CBSB1 significantly increased 44.2% of the dry weight of Brassica napus in the multimetal contaminated soil (P < 0.05) and showed no effect or declined the dry weight of B. alboglabra, B. campestris ssp. chinensis var. cummunis, B. campestris ssp. chinensis var. utilis cv. Youqing12, B. campestris ssp. chinensis var. utilis cv. Lvbao701 plants. The dry weights of B. napus, B. campestris ssp. chinensis var. utilis, and B. alboglabra showed a significant increase when the CBSB79 was inoculated (P < 0.05). In general, inoculation with bacteria and yeast did not greatly alter the metal concentration in plant tissues. Compared to Enterobacter sp. CBSB1, the yeast Rhodotorula sp CBSB79 showed higher potentials to improve extraction efficacy of Cd, Pb, Zn, and Cu by Brassica seedlings in the field.

The anatomical distribution and antimicrobial susceptibility of yeast species isolated from healthy dogs.

PubMed

Brito, Erika H S; Fontenelle, Raquel O S; Brilhante, Raimunda S N; Cordeiro, Rossana A; Monteiro, André J; Sidrim, José J C; Rocha, Marcos F G

2009-11-01

The aim of this work was to identify the predominant yeast species present at different anatomical sites in healthy dogs and to determine their in vitro antimicrobial susceptibility using a broth microdilution assay. Samples were collected from the preputial, vaginal, oral and perianal mucosae and the isolates cultured were identified according to their morphological characteristics and biochemical profile. Malassezia pachydermatis was the most commonly isolated yeast, followed by Candida parapsilosis, Candida tropicalis, Candida albicans, Saccharomyces cerevisiae and Rhodotorula spp. Minimum inhibitory concentrations of the azole derivatives ketoconazole, itraconazole and fluconazole against Candida spp. were 0.03-16 microg/mL, 0.06 to >16 microg/mL and 0.5-64 microg/mL, respectively and Candida isolates were sensitive to caspofungin and amphotericin B. Although all isolates of M. pachydermatis were sensitive to itraconazole, fluconazole, ketoconazole and amphotericin B, they were found to be resistant to caspofungin. The study has highlighted that Candida spp., M. pachydermatis, S. cerevisiae and Rhodotorula spp. are part of the normal canine surface microbiota and some of these organisms exhibit in vitro resistance to commonly used antimicrobials.

Identification, antifungal susceptibility and scanning electron microscopy of a keratinolytic strain of Rhodotorula mucilaginosa: a primary causative agent of onychomycosis.

PubMed

da Cunha, Marcel M L; dos Santos, Luana P B; Dornelas-Ribeiro, Marcos; Vermelho, Alane B; Rozental, Sonia

2009-04-01

Onychomycosis is a dermatological problem of high prevalence that mainly affects the hallux toenail. Onychomycosis caused by the yeast Rhodotorula mucilaginosa was identified using colony morphology, light microscopy, urease and carbohydrate metabolism in a 57-year-old immunocompetent patient from Rio de Janeiro, Brazil. High-resolution scanning electron microscopy of nail fragments, processed by a noncoating method, led to the observation with fine detail of the structures of both nail and fungus involved in the infection. Yeasts were mainly found inside grooves in the nail. Budding yeasts presented a spiral pattern of growth and blastoconidia were found in the nail groove region. Keratinase assays and keratin enzymography revealed that this isolate was highly capable of degrading keratin. Antifungal susceptibility tests showed that the fungus was susceptible to low concentrations of amphotericin B and 5-flucytosine and resistant to high concentrations of fluconazole, itraconazole, voriconazole and terbinafine. These findings showed data for the first time concerning the interaction of R. mucilaginosa in toenail infection and suggest that this emerging yeast should also be considered an opportunistic primary causative agent of onychomycosis.

Nail psoriasis masqueraded by secondary infection with Rhodotorula mucilaginosa.

PubMed

Martini, K; Müller, H; Huemer, H P; Höpfl, R

2013-11-01

A 38-year-old man presented with whitish nail changes on all fingers as the sole symptom. The condition had developed within a few days and led to dystrophy of the proximal part of the nail plates. As microscopic examination of nail scrapings demonstrated budding hyphae and the patient working as a teacher reported frequent use of a wet sponge, antifungal therapy was initiated. Subsequent cultures and molecular typing identified Rhodotorula mucilaginosa (formerly R. rubra). This environmental yeast was repeatedly isolated despite of therapy with itraconazole. As no improvement was achieved and testing of the biological activity of the fungus revealed only marginal keratolytic activity, it was considered as a coloniser of a destructed nail matrix. Finally, a biopsy of the nail bed confirmed the diagnosis of nail psoriasis, which rapidly responded to treatment with acitretin and topical calcipotriol/betamethasone cream. Fungal growth in destructed nails masqueraded the underlying disease and may have triggered the psoriatic nail reaction. © 2013 Blackwell Verlag GmbH.

Evaluation of pectinolytic activities for oenological uses from psychrotrophic yeasts.

PubMed

Sahay, S; Hamid, B; Singh, P; Ranjan, K; Chauhan, D; Rana, R S; Chaurse, V K

2013-08-01

Of the twenty-three morphotypes of yeasts isolated from soil capable of utilizing pectin as sole carbon source at 6°C, two yeast isolates, one psychrotolerant (PT1) and one psychrophilic (SPY11), were selected according to their ability to secrete pectinolytic enzymes under some oenological conditions (temperature 6 and 12°C and pH 3.5) and ability or inability to grow above 20°C, respectively. As compared to their optimal activity, the three pectinolytic enzymes viz., pectin methyl esterase (PME), endopolygalacturonase (endo-PG) and exopolygalacturonase (exo-PG) isolated and assayed at pH 3.5 from PT1 were found to retain 39, 60 and 60% activity at 12°C and 40, 79 and 74% activity at 28°C, respectively. Likewise, the enzymes PME and endo-PG at pH 3.5 from SPY11 displayed 46 and 86% activity at 12°C and 50 and 60% activity at 28°C, respectively. All these enzymes showed 20-90% of residual activity at pH 3.5 and 6°C. The yeast isolates PT1 and SPY11 were identified as Rhodotorula mucilaginosa and Cystofilobasidium capitatum, respectively, on the basis of morphological, physiological and molecular characteristics. This study presents the first report on pectinolytic activities under major oenological conditions from psychrotolerant isolate R. mucilaginosa PT1 and psychrophilic isolate C. capitatum SPY11. The cold-active pectinolytic enzymes (PME, endo-PG and exo-PG) from the newly isolated and identified psychrophilic yeast Cystofilobasidium capitatum SPY11 and psychrotolerant yeast Rhodotorula mucilaginosa PT1that exhibited 50-80% of their optimum activity under some major oenological conditions pH (3.5) and temperatures (6 and 12°C) could be applied to wine production and juice clarification at low temperature. The psychrotrophic yeasts themselves could be applied to cold process for the production of enzymes thus saving cost of energy and protecting process from contamination. © 2013 The Society for Applied Microbiology.

[Biosorption ability of mutants of Rhodotorula mucilaginosa UCM Y-1776].

PubMed

Mamieieva, O H; Kasatkina, T P; Lavrinchuk, V Ia

2007-01-01

Twenty stable mutants with various coloration intensity have been allocated in carotene-synthesizing natural strain Rhodotorula mucilaginosa UCM Y-1776 (wild type) after nitrosoguanidine action. Two brightly orange mutants 4L and 11 and one non-pigmented mutant 2 were chosen for the further researches. The ultraviolet was inefficient as a mutagen. Resistance to high concentration of copper ions (up to 200 mg/g), high sorption ability (Qmax = 9.1 mmol/g) was characteristic of R. mucilaginosa UCM Y-1776. Concentration of copper ions 50 mg/l was toxic for mutants 4L, 11 and 2, which sorption ability was lower in comparison with carotene pigmented R. mucilaginosa UCM Y-1776. It was shown, for the first time that there was a direct dependence between the presence of carotenoid pigments, resistance to high concentration of copper ions and sorption ability for yeast R. mucilaginosa UCM Y-1776.

Phylogenetic classification of yeasts and related taxa within Pucciniomycotina

PubMed Central

Wang, Q.-M.; Yurkov, A.M.; Göker, M.; Lumbsch, H.T.; Leavitt, S.D.; Groenewald, M.; Theelen, B.; Liu, X.-Z.; Boekhout, T.; Bai, F.-Y.

2016-01-01

Most small genera containing yeast species in the Pucciniomycotina (Basidiomycota, Fungi) are monophyletic, whereas larger genera including Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces are polyphyletic. With the implementation of the “One Fungus = One Name” nomenclatural principle these polyphyletic genera were revised. Nine genera, namely Bannoa, Cystobasidiopsis, Colacogloea, Kondoa, Erythrobasidium, Rhodotorula, Sporobolomyces, Sakaguchia and Sterigmatomyces, were emended to include anamorphic and teleomorphic species based on the results obtained by a multi-gene phylogenetic analysis, phylogenetic network analyses, branch length-based methods, as well as morphological, physiological and biochemical comparisons. A new class Spiculogloeomycetes is proposed to accommodate the order Spiculogloeales. The new families Buckleyzymaceae with Buckleyzyma gen. nov., Chrysozymaceae with Chrysozyma gen. nov., Microsporomycetaceae with Microsporomyces gen. nov., Ruineniaceae with Ruinenia gen. nov., Symmetrosporaceae with Symmetrospora gen. nov., Colacogloeaceae and Sakaguchiaceae are proposed. The new genera Bannozyma, Buckleyzyma, Fellozyma, Hamamotoa, Hasegawazyma, Jianyunia, Rhodosporidiobolus, Oberwinklerozyma, Phenoliferia, Pseudobensingtonia, Pseudohyphozyma, Sampaiozyma, Slooffia, Spencerozyma, Trigonosporomyces, Udeniozyma, Vonarxula, Yamadamyces and Yunzhangia are proposed to accommodate species segregated from the genera Bensingtonia, Rhodosporidium, Rhodotorula, Sporidiobolus and Sporobolomyces. Ballistosporomyces is emended and reintroduced to include three Sporobolomyces species of the sasicola clade. A total of 111 new combinations are proposed in this study. PMID:26951631

The effectiveness of photocatalytic ionisation disinfection of filter materials.

PubMed

Pietrzak, Katarzyna; Gutarowska, Beata

2013-01-01

The purpose of this study was to determine the effectiveness of photocatalytic ionisation as a disinfection method for filter materials contaminated by microorganisms, and to assess how air relative humidity (RH), time and microbe type influence the effectiveness of this disinfection. In the quantitative analysis of a used car air filter, bacterial contamination equalled 1.2 x 10(5) cfu/cm2, fungal contamination was 3.8 x 10(6) cfu/cm2, and the isolated microorganisms were Aspergillus niger, Bacillus megaterium, Cladosporium herbarum, Cryptococcus laurenti, Micrococcus sp., Rhodotorula glutinis and Staphylococcus cohnii. In the model experiment, three isolates (C. herbarum, R. glutinis, S. cohnii) and 3 ATCC species (A. niger, E. coli, S. aureus) were used for photocatalytic ionisation disinfection. The conditions of effective photocatalytic ionisation disinfection (R > or = 99.9%) were established as 2-3 h at RH = 77% (bacteria) and 6-24 h at RH = 53% (fungi). RH has an influence on the effectiveness of the photocatalytic disinfection process; the highest effectiveness was obtained for bacteria at RH = 77%, with results 5% higher than for RH = 49%. The studies show that the sensitivity of microorganisms to photocatalytic ionisation disinfection is ordered as follows: Gram-positive bacteria (S. cohnii, S. aureus), Gram-negative bacteria (E. coli), yeasts (R. glutinis), and moulds (C. herbarum, A. niger). Of all the mathematical models used for the description of death dynamics after photocatalytic ionisation disinfection, the Chick-Watson model is the most useful, but for more resistant microorganisms, the delayed Chick-Watson model is highly recommended. It therefore seems, that the presented disinfection method of photocatalytic ionisation can be successfully used to clean filtration materials.

Activities of Available and Investigational Antifungal Agents against Rhodotorula Species

PubMed Central

Diekema, D. J.; Petroelje, B.; Messer, S. A.; Hollis, R. J.; Pfaller, M. A

2005-01-01

Rhodotorula species are emerging pathogens in immunocompromised patients. We report the in vitro activities of eight antifungals against 64 Rhodotorula isolates collected in surveillance programs between 1987 and 2003. Rhodotorula strains are resistant in vitro to fluconazole (MIC at which 50% of the isolates tested are inhibited [MIC50], >128 μg/ml) and caspofungin (MIC50, >8 μg/ml). Amphotericin B (MIC50,1 μg/ml) and flucytosine (MIC50, 0.12 μg/ml) are both active in vitro, and the new and investigational triazoles all have some in vitro activity, with ravuconazole being the most active (MIC50, 0.25 μg/ml). PMID:15635020

Isolation of clinically relevant fungal species from solid waste and environment of dental health services.

PubMed

Vieira, C D; de Carvalho, M A R; de Resende, M A; de Menezes Cussiol, N A; Alvarez-Leite, M E; dos Santos, S G; de Oliveira, M B; de Magalhães, T F F; Silva, M X; Nicoli, J R; de Macêdo Farias, L

2010-10-01

This study was undertaken to detect, identify and determine antifungal susceptibility of yeast strains isolated from dental solid waste and to evaluate airborne fungi in the Brazilian dental health care environment and in the waste storage room. A group of 17 yeast strains were identified by macroscopic and microscopic characteristics, API 20C Aux system and Multiplex PCR. All 104 airborne fungal colonies were identified by macroscopic and microscopic morphology. The CLSI broth microdilution method was utilized as the susceptibility test. Candida parapsilosis was the prevailing yeast species recovered from waste, followed by Rhodotorula glutinis. Three strains of Candida guilliermondii presented minimal inhibitory concentration values considered to be susceptible dose dependent (2 μg ml(-1)) to voriconazole. Of all airborne fungal species, 69% were recovered from the waste storage room and 31% were recovered from the clinical/surgical environment. Most of them were identified as Cladosporium spp. These findings reinforce the potential risk of waste handling and point out the need for safe management to minimize the spread of these agents to the environment. Filamentous fungi isolation in almost all sampled environments indicates that a periodic monitoring of airborne microbiota in the dental health care service environment is required. The survival of yeast strains for 48 h suggests that dental waste should be carefully controlled and monitored. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Chitin enhances biocontrol of Rhodotorula mucilaginosa to postharvest decay of peaches.

PubMed

Zhang, Hongyin; Yang, Qiya; Ge, Lingling; Zhang, Guochao; Zhang, Xiaoli; Zhang, Xiaoyun

2016-07-01

Biological control using microbial antagonists is a promising alternative approach to synthetic fungicides. However, effective biological control requires enhancing the consistency and efficacy of the antagonists used to control postharvest diseases. This study investigated the effect of chitin on the biocontrol efficacy of Rhodotorula mucilaginosa against blue mold and Rhizopus decay of peaches and on the protein expression profiles of R. mucilaginosa. The antagonistic activity of R. mucilaginosa harvested from the nutrient yeast dextrose broth (NYDB) with 0.5% chitin added was significantly improved compared with culture in NYDB without chitin. The R. mucilaginosa population cultured in chitin-supplement NYDB and nutrient yeast chitin borth (NYCB) harvested from peach wounds was more than that of R. mucilaginosa cultured in NYDB without chitin throughout the storage period except at 1 d. The protein expression profiles findings revealed that there were several differentially expressed proteins of R. mucilaginosa in the 0.5% chitin-supplemented NYDB and NYCB compared with that of R. mucilaginosa in NYDB. Most of these were cellular proteomes relating to the primary metabolic reactions such as glycoside hydrolases, phosphoribosyl pyrophosphate, and NADH dehydrogenases. Some proteins were also related to signal transmission and stress response. Copyright © 2016 Elsevier B.V. All rights reserved.

Culturable yeasts in meltwaters draining from two glaciers in the Italian Alps

NASA Astrophysics Data System (ADS)

Buzzini, Pietro; Turchetti, Benedetta; Diolaiuti, Guglielmina; D'Agata, Carlo; Martini, Alessandro; Smiraglia, Claudio

The meltwaters draining from two glaciers in the Italian Alps contain metabolically active yeasts isolable by culture-based laboratory procedures. The average number of culturable yeast cells in the meltwaters was 10 20 colony-forming units (CFU) L-1, whereas supraglacial stream waters originating from overlying glacier ice contained <1 CFU L-1. Yeast cell number increased as the suspended-sediment content of the water samples increased. Basidiomycetous yeasts represent >80% of isolated strains (Cryptococcus spp. and Rhodotorula spp. were 33.3% and 17.8% of total strains, respectively). Culturable yeasts were psychrotolerant, predominantly obligate aerobes and able to degrade organic macromolecules (e.g. starch, esters, lipids, proteins). To the authors' knowledge, this is the first study to report the presence of culturable yeasts in meltwaters originating from glaciers. On the basis of these results, it is reasonable to suppose that the viable yeasts observed in meltwaters derived predominantly from the subglacial zone and that they originated from the subglacial microbial community. Their metabolic abilities could contribute to the microbial activity occurring in subglacial environments.

Reverse Osmosis Water Purification Unit: Efficacy of Cartridge Filters for Removal of Bacteria and Protozoan Cysts when Ro Elements are Bypassed

DTIC Science & Technology

1993-04-01

were Klebsiella terrigena, Cryptosporidium parvum oocysts, Rhodotorula rubra, and 3.7 pm latex beads. Challenge waters were dechlorinated tap water and...The morphological and size characteristics of Rhodotorula rubra (ATCC 36053) made the yeast suitable as a protozoan cyst simulant. The yeast cells...representative enteric bacterium), Cryptosporidium parvum (an enteric protozoan pathogen) oocysts, Rhodotorula rubra (a yeast, used to test prefilters only

Lipids of Rhodotorula mucilaginosa IIPL32 with biodiesel potential: Oil yield, fatty acid profile, fuel properties.

PubMed

Khot, Mahesh; Ghosh, Debashish

2017-04-01

This study analyzes the single cell oil (SCO), fatty acid profile, and biodiesel fuel properties of the yeast Rhodotorula mucilaginosa IIPL32 grown on the pentose fraction of acid pre-treated sugarcane bagasse as a carbon source. The yeast biomass from nitrogen limiting culture conditions (15.3 g L -1 ) was able to give the SCO yield of 0.17 g g -1 of xylose consumed. Acid digestion, cryo-pulverization, direct in situ transesterification, and microwave assisted techniques were evaluated in comparison to the Soxhlet extraction for the total intracellular yeast lipid recovery. The significant differences were observed among the SCO yield of different methods and the in situ transesterification stood out most for effective yeast lipid recovery generating 97.23 mg lipid as FAME per gram dry biomass. The method was fast and consumed lesser solvent with greater FAME yield while accessing most cellular fatty acids present. The yeast lipids showed the major presence of monounsaturated fatty esters (35-55%; 18:1, 16:1) suitable for better ignition quality, oxidative stability, and cold-flow properties of the biodiesel. Analyzed fuel properties (density, kinematic viscosity, cetane number) of the yeast oil were in good agreement with international biodiesel standards. The sugarcane bagasse-derived xylose and the consolidated comparative assessment of lab scale SCO recovery methods highlight the necessity for careful substrate choice and validation of analytical method in yeast oil research. The use of less toxic co-solvents together with solvent recovery and recycling would help improve process economics for sustainable production of biodiesel from the hemicellulosic fraction of cheap renewable sources. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The influence of Aster x salignus Willd. Invasion on the diversity of soil yeast communities

NASA Astrophysics Data System (ADS)

Glushakova, A. M.; Kachalkin, A. V.; Chernov, I. Yu.

2016-07-01

The annual dynamics of yeast communities were studied in the soddy-podzolic soil under the thickets of Aster x salignus Willd., one of the widespread invasive plant species in central Russia. Yeast groups in the soils under continuous aster thickets were found to differ greatly from the yeast communities in the soils under the adjacent indigenous meadow vegetation. In both biotopes the same species ( Candida vartiovaarae, Candida sake, and Cryptococcus terreus) are dominants. However, in the soils under indigenous grasses, eurybiontic yeasts Rhodotorula mucilaginosa, which almost never occur in the soil under aster, are widespread. In the soil under aster, the shares of other typical epiphytic and pedobiontic yeast fungi (ascomycetic species Wickerhamomyces aniomalus, Barnettozyma californica and basidiomycetic species Cystofilobasidium macerans, Guehomyces pullulans) significantly increase. Thus, the invasion of Aster x salignus has a clear effect on soil yeast complexes reducing their taxonomic and ecological diversity.

Spores of the mycorrhizal fungus Glomus mosseae host yeasts that solubilize phosphate and accumulate polyphosphates.

PubMed

Mirabal Alonso, Loreli; Kleiner, Diethelm; Ortega, Eduardo

2008-04-01

The present paper reports the presence of bacteria and yeasts tightly associated with spores of an isolate of Glomus mosseae. Healthy spores were surface disinfected by combining chloramine-T 5%, Tween-40, and cephalexin 2.5 g L(-1) (CTCf). Macerates of these spores were incubated on agar media, microorganisms were isolated, and two yeasts were characterized (EndoGm1, EndoGm11). Both yeasts were able to solubilize low-soluble P sources (Ca and Fe phosphates) and accumulate polyphosphates (polyPs). Sequence analysis of 18S ribosomal deoxyribonucleic acid showed that the yeasts belong to the genera Rhodotorula or Rhodosporidium (EndoGm1) and Cryptococcus (EndoGm11). Results from inoculation experiments showed an effect of the spore-associated yeasts on the root growth of rice, suggesting potential tripartite interactions with mycorrhizal fungi and plants.

Rare opportunistic (non-Candida, non-Cryptococcus) Yeast Bloodstream Infections in Patients with Cancer

PubMed Central

Chitasombat, Maria N.; Kofteridis, Diamantis P.; Jiang, Ying; Tarrand, Jeffrey; Lewis, Russell E.; Kontoyiannis, Dimitrios P.

2013-01-01

Background Rare opportunistic (non-Candida, non-Cryptococcus) yeast bloodstream infections (ROYBSIs) are rare, even in cancer patients. Methods We retrospectively reviewed all episodes of ROYBSIs occurring from 1998 to 2010 in our cancer center. Results Of 2984 blood cultures positive for Candida and non-Candida yeasts, 94 (3.1%) were positive for non-Candida yeasts, representing 41 ROYBSIs (incidence, 2.1 cases/100,000 patient-days). Catheter-associated fungemia occurred in 21 (51%) patients. Breakthrough ROYBSIs occurred in 20 (49%) patients. The yeast species distribution was Rhodotorula in 21 (51%) patients, Trichosporon in 8 (20%) patients, Saccharomyces cerevisiae in 8 (20%) patients, Geotrichum in 2 (5%) patients, Pichia anomala, and Malassezia furfur in 1 patient each. All tested Trichosporon, Geotrichum, and Pichia isolates were azole-susceptible, whereas the Rhodotorula isolates were mostly azole-resistant. We noted echinocandin nonsusceptibility (minimal inhibitory concentration ≥ 2 mg/L) in all but the S. cerevisiae isolates. Most of the isolates (28/33 [85%]) were susceptible to amphotericin B. The mortality rate in all patients at 30 days after ROYBSIs diagnosis was 34%. Multivariate survival analysis revealed increased risk of death in patients with S. cerevisiae infections (hazard ratio, 3.7), Geotrichum infections (hazard ratio, 111.3), or disseminated infections (hazard ratio, 33.4) and reduced risk in patients who had catheter removal (hazard ratio, 0.1). Conclusions ROYBSIs are uncommon in patients with cancer, and catheters are common sources of them. Half of the ROYBSIs occurred as breakthrough infections, and in vitro species-specific resistance to echinocandins and azoles was common. Disseminated infections resulted in the high mortality rate. PMID:22101079

Anti-Rhodotorula activity of mycophenolic acid enhanced in the presence of polyene antibiotic nystatin.

PubMed

Kinoshita, H; Wongsuntornpoj, S; Ihara, F; Nihira, T

2017-02-01

Rhodotorula species are opportunistic pathogens, which cause not only systemic fungaemia but also other localized infections. Despite serious side effects such as nephrotoxicity and hypokalemia, amphotericin B (a polyene antifungal) has been commonly prescribed for Rhodotorula infection because Rhodotorula species are resistant against a candin family of antifungal agents. In this study, novel active compounds against Rhodotorula species were screened from the extracts of entomopathogenic fungi based on the synergistic effect of polyene nystatin (NYS), which causes efficient targeting of compounds due to increased permeability through the fungal cell membrane. Around 37% of culture extracts from 31 entomopathogenic fungal strains showed anti-Rhodotorula activity in the synergistic bioassay system, suggesting that the coexistence assay with NYS enhanced the discovery of anti-Rhodotorula compounds. Judging from various physicochemical data, the active component from strain HF763 was identified as an immunosuppressant drug, mycophenolic acid (MPA). The minimum inhibitory concentration of MPA against three pathogenic Rhodotorula strains was determined, focusing on the synergistic effect with NYS. The results revealed that the values decreased by at least 87% in the presence of NYS, indicating that MPA showed a synergistic effect with NYS. This study aimed to screen active compounds against Rhodotorula species that are resistant to a candin family of antifungal agents, from entomopathogenic fungi. Assuming that most of the latent antifungal compounds do not exert their activity due to their inability to penetrate the membrane, we took advantage of polyene nystatin in the screening to increase permeability through the fungal cell membrane. The result of the screening revealed hidden antifungal activity of mycophenolic acid, demonstrating that the method applied in this study unlocks the potentials of bioresources, and proposes a new remedy for mycosis. © 2016 The

Tolerance to Ultraviolet Radiation of Psychrotolerant Yeasts and Analysis of Their Carotenoid, Mycosporine, and Ergosterol Content.

PubMed

Villarreal, Pablo; Carrasco, Mario; Barahona, Salvador; Alcaíno, Jennifer; Cifuentes, Víctor; Baeza, Marcelo

2016-01-01

Yeasts colonizing the Antarctic region are exposed to a high ultraviolet radiation evolving mechanisms to minimize the UV radiation damages, such as the production of UV-absorbing or antioxidant compounds like carotenoid pigments and mycosporines. Ergosterol has also been suggested to play a role in this response. These compounds are also economically attractive for several industries such as pharmaceutical and food, leading to a continuous search for biological sources of them. In this work, the UV-C radiation tolerance of yeast species isolated from the sub-Antarctic region and their production of carotenoids, mycosporines, and ergosterol were evaluated. Dioszegia sp., Leuconeurospora sp. (T27Cd2), Rhodotorula laryngis, Rhodotorula mucilaginosa, and Cryptococcus gastricus showed the highest UV-C radiation tolerance. The yeasts with the highest content of carotenoids were Dioszegia sp. (OHK torulene), Rh. laryngis (torulene and lycopene), Rh. mucilaginosa, (torulene, gamma carotene, and lycopene), and Cr. gastricus (2-gamma carotene). Probable mycosporine molecules and biosynthesis intermediates were found in Rh. laryngis, Dioszegia sp., Mrakia sp., Le. creatinivora, and Leuconeurospora sp. (T27Cd2). Ergosterol was the only sterol detected in all yeasts, and M. robertii and Le. creatinivora showed amounts higher than 4 mg g−1. Although there was not a well-defined relation between UV-C tolerance and the production of these three kinds of compounds, the majority of the yeasts with lower amounts of carotenoids showed lower UV-C tolerance. Dioszegia sp., M. robertii, and Le. creatinivora were the greatest producers of carotenoids, ergosterol, and mycosporines, respectively, representing good candidates for future studies intended to increase their production for large-scale applications.

Enhanced biocontrol activity of Rhodotorula mucilaginosa cultured in media containing chitosan against postharvest diseases in strawberries: possible mechanisms underlying the effect.

PubMed

Zhang, Hongyin; Ge, Lingling; Chen, Keping; Zhao, Lina; Zhang, Xiaoyun

2014-05-07

The effect of Rhodotorula mucilaginosa cultured in media containing chitosan on its antogonistic activity against postharvest diseases of strawberries and the possible mechanisms involved are discussed. Two-dimensional gel electrophoresis were applied in the analysis of the proteins of R. mucilaginosa in response to chitosan. Compared with the application of R. mucilaginosa alone, the biocontrol efficacy of the yeast combined with 0.5% chitosan was enhanced greatly, with significant increase in chitinase activity of antagonistic yeast, polyphenoloxidase, peroxidase, phenylalanine ammonia lyase, chitinase and β-1,3-glucanase activity, and with an inhibition of lipid peroxidation of strawberries. The population of R. mucilaginosa harvested from NYDB amended with chitosan at 0.5% increased rapidly in strawberry wounds compared with those harvested from NYDB without chitosan. In the cellular proteome, several differentially expressed proteins were identified, most of which were related to basic metabolism.

Characterization of butter spoiling yeasts and their inhibition by some spices.

PubMed

Sagdic, Osman; Ozturk, Ismet; Bayram, Okan; Kesmen, Zulal; Yilmaz, Mustafa Tahsin

2010-01-01

This study was designed to identify the yeasts in packaged and unpackaged butters and screen antiyeast activity of spices, including marjoram (Origanum majorana L.), summer savory (Satureja hortensis L.), and black cumin (Nigella sativa L.) against the most dominant yeast species in the packaged and unpackaged butters. Mean total yeast populations were 5.40 log CFU/g in unpackaged butter samples and 2.22 log CFU/g in packaged butter samples, indicating better hygienic quality of packaged samples. Forty-nine yeast species were isolated and identified from butter samples with the most prevalent isolates belonging to genera Candida-C. kefyr, C. zeylanoides, and C. lambica-and with moderate number of isolates belonging to genera Cryptococcus, Rhodotorula, Saccharomyces, and Zygosaccharomyces. Black cumin exhibited the highest antiyeast activity against C. zeylanoides and C. lambica species, even inhibited these species, while summer savory inhibited C. kefyr. The results of this study revealed clear antimicrobial potential of black cumin against the yeast species isolated from butters. Marjoram, summer savory, and black cumin could be used as natural antimicrobial agents against spoilage yeasts in food preservation, especially in butter. © 2010 Institute of Food Technologists®

Rhodotorula mucilaginosa, a quorum quenching yeast exhibiting lactonase activity isolated from a tropical shoreline.

PubMed

Ghani, Norshazliza Ab; Sulaiman, Joanita; Ismail, Zahidah; Chan, Xin-Yue; Yin, Wai-Fong; Chan, Kok-Gan

2014-04-09

Two microbial isolates from a Malaysian shoreline were found to be capable of degrading N-acylhomoserine lactones. Both Matrix Assisted Laser Desorption Ionization-Time of Flight-Mass Spectrometry and 18S rDNA phylogenetic analyses confirmed that these isolates are Rhodotorula mucilaginosa. Quorum quenching activities were detected by a series of bioassays and rapid resolution liquid chromatography analysis. The isolates were able to degrade various quorum sensing molecules namely N-hexanoyl-L-homoserine lactone (C6-HSL), N-(3-oxo-hexanoyl)-L-homoserine lactone (3-oxo-C6-HSL) and N-(3-hydroxyhexanoyl)-L-homoserine lactone (3-hydroxy-C6-HSL). Using a relactonisation assay to verify the quorum quenching mechanism, it is confirmed that Rh. mucilaginosa degrades the quorum sensing molecules via lactonase activity. To the best of our knowledge, this is the first documentation of the fact that Rh. mucilaginosa has activity against a broad range of AHLs namely C6-HSL, 3-oxo-C6-HSL and 3-hydroxy-C6-HSL.

Rhodotorula Mucilaginosa, a Quorum Quenching Yeast Exhibiting Lactonase Activity Isolated from a Tropical Shoreline

PubMed Central

Ghani, Norshazliza Ab; Sulaiman, Joanita; Ismail, Zahidah; Chan, Xin-Yue; Yin, Wai-Fong; Chan, Kok-Gan

2014-01-01

Two microbial isolates from a Malaysian shoreline were found to be capable of degrading N-acylhomoserine lactones. Both Matrix Assisted Laser Desorption Ionization-Time of Flight-Mass Spectrometry and 18S rDNA phylogenetic analyses confirmed that these isolates are Rhodotorula mucilaginosa. Quorum quenching activities were detected by a series of bioassays and rapid resolution liquid chromatography analysis. The isolates were able to degrade various quorum sensing molecules namely N-hexanoyl-L-homoserine lactone (C6-HSL), N-(3-oxo-hexanoyl)-L-homoserine lactone (3-oxo-C6-HSL) and N-(3-hydroxyhexanoyl)-L-homoserine lactone (3-hydroxy-C6-HSL). Using a relactonisation assay to verify the quorum quenching mechanism, it is confirmed that Rh. mucilaginosa degrades the quorum sensing molecules via lactonase activity. To the best of our knowledge, this is the first documentation of the fact that Rh. mucilaginosa has activity against a broad range of AHLs namely C6-HSL, 3-oxo-C6-HSL and 3-hydroxy-C6-HSL. PMID:24721765

Industrially Important Carbohydrate Degrading Enzymes from Yeasts: Pectinases, Chitinases, and β-1,3-Glucanases

NASA Astrophysics Data System (ADS)

Gummadi, Sathyanarayana N.; Kumar, D. Sunil; Dash, Swati S.; Sahu, Santosh Kumar

Polysaccharide degrading enzymes are hydrolytic enzymes, which have a lot of industrial potential and also play a crucial role in carbon recycling. Pectinases, chitinases and glucanases are the three major polysaccharide degrading enzymes found abundantly in nature and these enzymes are mainly produced by fungal strains. Production of these enzymes by yeasts is advantageous over fungi, because the former are easily amenable to genetic manipulations and time required for growth and production is less than that of the latter. Several yeasts belonging to Saccharomyces, Pichia, Rhodotorula and Cryptococcus produce extracellular pectinases, glucanases and chitinases. This chapter emphasizes on the biological significance of these enzymes, their production and their industrial applications.

Interactions between yeasts and bacteria in the smear surface-ripened cheeses.

PubMed

Corsetti, A; Rossi, J; Gobbetti, M

2001-09-19

In the initial phase of ripening, the microflora of bacterial smear surface-ripened cheeses such as Limburger, Taleggio, Brick, Münster and Saint-Paulin and that of surface mould-ripened cheeses such as Camembert and Brie may be similar, but at the end of the ripening, bacteria such as Brevibacterium spp., Arthrobacter spp., Micrococcus spp., Corynebacterium spp. and moulds such as Penicillium camemberti are, respectively, the dominant microorganisms. Yeasts such as Candida spp., Cryptococcus spp., Debaryomyces spp., Geotrichum candidum, Pichia spp., Rhodotorula spp., Saccharomyces spp. and Yarrowia lipolytica are often and variably isolated from the smear surface-ripened cheeses. Although not dominant within the microorganisms of the smear surface-ripened cheeses, yeasts establish significant interactions with moulds and especially bacteria, including surface bacteria and lactic acid bacteria. Some aspects of the interactions between yeasts and bacteria in such type of cheeses are considered in this paper.

Isolation and characterization of yeasts associated with plants growing in heavy-metal- and arsenic-contaminated soils.

PubMed

Ramos-Garza, Juan; Bustamante-Brito, Rafael; Ángeles de Paz, Gabriela; Medina-Canales, Ma Gabriela; Vásquez-Murrieta, María Soledad; Wang, En Tao; Rodríguez-Tovar, Aída Verónica

2016-04-01

Yeasts were quantified and isolated from the rhizospheres of 5 plant species grown at 2 sites of a Mexican region contaminated with arsenic, lead, and other heavy metals. Yeast abundance was about 10(2) CFU/g of soil and 31 isolates were obtained. On the basis of the phylogenetic analysis of 26S rRNA and internal transcribed spacer fragment, 6 species were identified within the following 5 genera: Cryptococcus (80.64%), Rhodotorula (6.45%), Exophiala (6.45%), Trichosporon (3.22%), and Cystobasidium (3.22%). Cryptococcus spp. was the predominant group. Pectinases (51.6%), proteases (51.6%), and xylanases (41.9%) were the enzymes most common, while poor production of siderophores (16.1%) and indole acetic acid (9.67%) was detected. Isolates of Rhodotorula mucilaginosa and Cystobasidium sloffiae could promote plant growth and seed germination in a bioassay using Brassica juncea. Resistance of isolates by arsenic and heavy metals was as follows: As(3+) ≥ 100 mmol/L, As(5+) ≥ 30 mmol/L, Zn(2+) ≥ 2 mmol/L, Pb(2+) ≥ 1.2 mmol/L, and Cu(2+) ≥ 0.5 mmol/L. Strains of Cryptococcus albidus were able to reduce arsenate (As(5+)) into arsenite (As(3+)), but no isolate was capable of oxidizing As(3+). This is the first study on the abundance and identification of rhizosphere yeasts in a heavy-metal- and arsenic-contaminated soil, and of the reduction of arsenate by the species C. albidus.

The ability of a cold-adapted Rhodotorula mucilaginosa strain from Tibet to control blue mold in pear fruit.

PubMed

Hu, Hao; Yan, Fujie; Wilson, Charles; Shen, Qing; Zheng, Xiaodong

2015-12-01

Cold-adapted yeasts were isolated from soil samples collected in Tibet and evaluated as potential biocontrol agents against blue mold (Penicillium expansum) of pear fruit in cold storage. YC1, an isolate identified as Rhodotorula mucilaginosa, was found to exhibit the greatest biocontrol activity among the different isolates that were screened. A washed cell suspension of YC1 exhibited the best biocontrol activity among three different preparations that were used in the current study. A concentration of 10(8) cells/ml reduced the incidence of decay to 35 %, compared to the control where decay incidence was 100 %. A higher intracellular level of trehalose and a higher proportion of polyunsaturated acids present in YC1, was associated with increased the tolerance of this strain to low temperatures, relative to the other strains that were evaluated. The increased tolerance to low temperature allowed the YC1 strain of yeast to more effectively compete for nutrients and space in wounded pear fruit that had been inoculated with spores of P. expansum and placed in cold storage. The present study demonstrated the ability to select cold-adapted yeasts from cold climates and use them as biocontrol agents of postharvest diseases of fruit placed in cold storage.

Recycling of food waste for fuel precursors using an integrated bio-refinery approach.

PubMed

Karthikeyan, O P; Nguyen Hao, H T; Razaghi, Ali; Heimann, Kirsten

2018-01-01

The main aim was to integrate FW-recycling with cultivation of Rhodotorula glutinis and anaerobic digestion (AD) for bio-energy and -fuel recovery. Mixed FW was mechanically macerated (Pcon) and hydrolysed (at 250gL -1 water) via chemical (Ch), thermal (Th) and TCh (combined Ch and Th) treatments. Cleared hydrolysates from individual pre-treatment processes were used as culture medium for cultivation of R. glutinis, while the residual solids (RS) were subjected to AD. Pcon cultivation yielded maximal R. glutinis dry weight biomass (5.18gL -1 ) and total fatty acid contents (1.03gg -1 DW biomass ). Dominant fatty acid methyl esters (FAME) were Palmitic - (C 16:0 -26%); Stearic - (C 18:0 -17%) and Oleic acids (C 18:1 -38%), ideal for bio-diesel production. Highest methane yields (actual ∼0.139m 3 kg -1 volatile solids) were measured from AD of Th-derived RS. Thus integrated FW recycling approaches will be more feasible for generating energy and economic incentives. Copyright © 2017 Elsevier Ltd. All rights reserved.

MALDI-TOF MS as a tool to identify foodborne yeasts and yeast-like fungi.

PubMed

Quintilla, Raquel; Kolecka, Anna; Casaregola, Serge; Daniel, Heide M; Houbraken, Jos; Kostrzewa, Markus; Boekhout, Teun; Groenewald, Marizeth

2018-02-02

Since food spoilage by yeasts causes high economic losses, fast and accurate identifications of yeasts associated with food and food-related products are important for the food industry. In this study the efficiency of the matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify food related yeasts was evaluated. A CBS in-house MALDI-TOF MS database was created and later challenged with a blinded test set of 146 yeast strains obtained from food and food related products. Ninety eight percent of the strains were correctly identified with log score values>1.7. One strain, Mrakia frigida, gained a correct identification with a score value<1.7. Two strains could not be identified at first as they represented a mix of two different species. These mixes were Rhodotorula babjevae with Meyerozyma caribbica and Clavispora lusitaniae with Debaryomyces hansenii. After separation, all four species could be correctly identified with scores>1.7. Ambiguous identifications were observed due to two incorrect reference mass spectra's found in the commercial database BDAL v.4.0, namely Candida sake DSM 70763 which was re-identified as Candida oleophila, and Candida inconspicua DSM 70631 which was re-identified as Pichia membranifaciens. MALDI-TOF MS can distinguish between most of the species, but for some species complexes, such as the Kazachstania telluris and Mrakia frigida complexes, MALDI-TOF MS showed limited resolution and identification of sibling species was sometimes problematic. Despite this, we showed that the MALDI-TOF MS is applicable for routine identification and validation of foodborne yeasts, but a further update of the commercial reference databases is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schneider, Teresa; Graeff-Honninger, Simone; French, William Todd

The production of biodiesel has notably increased over the past decade. Currently, plant oil is the main feedstock for biodiesel production, but, due to concerns related to the competition with food production, alternative oil feedstocks have to be found. Oleaginous yeasts are known to produce high amounts of lipids, but no integrated process from microbial fermentation to final biodiesel production has reached commercial realization yet due to economic constraints. Therefore, growth and lipid production of red yeast Rhodotorula glutinis was tested on low-cost substrates, namely, wastewaters from potato, fruit juice, and lettuce processing. Additionally, the production of carotenoids as high-valuemore » by-products was examined. All evaluated wastewaters met the general criteria for microbial lipid production. However, no significant increase in lipid content was observed, probably due to lack of available carbon in wastewaters from fruit juice and lettuce processing, and excess of available nitrogen in potato processing wastewater, respectively. During growth on wastewaters from fruit juice and lettuce processing the carotenoid content increased significantly in the first 48 hours. The relations between carbon content, nitrogen content, and carotenoid production need to be further assessed. For economic viability, lipid and carotenoid production needs to be increased significantly. Lastly, the screening of feedstocks should be extended to other wastewaters.« less

Screening of industrial wastewaters as feedstock for the microbial production of oils for biodiesel production and high-quality pigments

DOE PAGES

Schneider, Teresa; Graeff-Honninger, Simone; French, William Todd; ...

2012-01-01

The production of biodiesel has notably increased over the past decade. Currently, plant oil is the main feedstock for biodiesel production, but, due to concerns related to the competition with food production, alternative oil feedstocks have to be found. Oleaginous yeasts are known to produce high amounts of lipids, but no integrated process from microbial fermentation to final biodiesel production has reached commercial realization yet due to economic constraints. Therefore, growth and lipid production of red yeast Rhodotorula glutinis was tested on low-cost substrates, namely, wastewaters from potato, fruit juice, and lettuce processing. Additionally, the production of carotenoids as high-valuemore » by-products was examined. All evaluated wastewaters met the general criteria for microbial lipid production. However, no significant increase in lipid content was observed, probably due to lack of available carbon in wastewaters from fruit juice and lettuce processing, and excess of available nitrogen in potato processing wastewater, respectively. During growth on wastewaters from fruit juice and lettuce processing the carotenoid content increased significantly in the first 48 hours. The relations between carbon content, nitrogen content, and carotenoid production need to be further assessed. For economic viability, lipid and carotenoid production needs to be increased significantly. Lastly, the screening of feedstocks should be extended to other wastewaters.« less

Yeasts from sub-Antarctic region: biodiversity, enzymatic activities and their potential as oleaginous microorganisms.

PubMed

Martinez, A; Cavello, I; Garmendia, G; Rufo, C; Cavalitto, S; Vero, S

2016-09-01

Various microbial groups are well known to produce a range of extracellular enzymes and other secondary metabolites. However, the occurrence and importance of investment in such activities have received relatively limited attention in studies of Antarctic soil microbiota. Sixty-one yeasts strains were isolated from King George Island, Antarctica which were characterized physiologically and identified at the molecular level using the D1/D2 region of rDNA. Fifty-eight yeasts (belonging to the genera Cryptococcus, Leucosporidiella, Rhodotorula, Guehomyces, Candida, Metschnikowia and Debaryomyces) were screened for extracellular amylolytic, proteolytic, esterasic, pectinolytic, inulolytic xylanolytic and cellulolytic activities at low and moderate temperatures. Esterase activity was the most common enzymatic activity expressed by the yeast isolates regardless the assay temperature and inulinase was the second most common enzymatic activity. No cellulolytic activity was detected. One yeast identified as Guehomyces pullulans (8E) showed significant activity across six of seven enzymes types tested. Twenty-eight yeast isolates were classified as oleaginous, being the isolate 8E the strain that accumulated the highest levels of saponifiable lipids (42 %).

Yeast diversity associated to sediments and water from two Colombian artificial lakes

PubMed Central

Silva-Bedoya, L.M.; Ramírez-Castrillón, M.; Osorio-Cadavid, E.

2014-01-01

In Colombia, knowledge of the yeast and yeast-like fungi community is limited because most studies have focused on species with clinical importance. Sediments and water represent important habitats for the study of yeast diversity, especially for yeast species with industrial, biotechnological, and bioremediation potential. The main purpose of this study was to identify and compare the diversity of yeast species associated with sediment and water samples from two artificial lakes in Universidad del Valle (Cali-Colombia). Yeast samplings were performed from fifteen sediment samples and ten water samples. Grouping of similar isolates was initially based on colony and cell morphology, which was then complemented by micro/mini satellite primed PCR banding pattern analysis by using GTG5 as single primer. A representative isolate for each group established was chosen for D1/D2 domain sequencing and identification. In general, the following yeast species were identified: Candida albicans, Candida diversa, Candida glabrata, Candida pseudolambica, Cryptococcus podzolicus, Cryptococcus rajasthanensis, Cryptococcus laurentii, Williopsis saturnus, Hanseniaspora thailandica, Hanseniaspora uvarum, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, Torulaspora delbrueckii, Torulaspora pretoriensis, Tricosporon jirovecii, Trichosporon laibachii and Yarrowia lypolitica. Two possible new species were also found, belonging to the Issatchenkia sp. and Bullera sp. genera. In conclusion, the lakes at the Universidad del Valle campus have significant differences in yeast diversity and species composition between them. PMID:24948924

Screening and identification of a cutinase-producing Rhodotorula mucilaginosa and properties of the cutinase.

PubMed

Zhang, Xiao-Ning; Ran, Qin-Qin; Zhang, Xuejun

2015-01-01

Eucommia leaf contains large amounts of natural active products. In extracting the substances, the most important is the removal of the cuticle layer on the leaves and the cell wall in the leaves of Eucommia ulmoides. But the removal of the cuticle layer is a technical difficulty now. Cutinase (EC3.1.1.74) is a multifunctional enzyme with a common alpha/beta fold structure belonging to hydroplane that can make a substantial degradation of horny fatty acids. So this study isolated bacteria capable of producing cutinase from the lesion of Eucommia leaves and identified the bacteria. The identification using PCR-RFLP method confirmed that the strain belongs to Rhodotorula mucilaginosa. The fermentation conditions of the strain-producing cutinase were optimized in this study. The finding of cutinase-producing R. mucilaginosa is significant because the yeast is more secure than plant pathogens, being suitable for mass production.

Meningitis caused by Rhodotorula mucilaginosa in human immunodeficiency virus seropositive patient

PubMed Central

Baradkar, V. P.; Kumar, S.

2008-01-01

Rhodotorula species may be responsible for systemic infection in immunocompromised patients. Meningitis by Rhodotorula species in human immunodeficiency virus (HIV) infected persons has been reported previously. We report a case of meningitis caused by Rhodotorula mucilaginosa in a 36-year-old HIV seropositive male patient who presented with fever, altered sensorium and features of meningeal irritation i.e. neck rigidity. The Cerebrospinal fluid (CSF) cell counts were high, showing 150 cells/mm3, with 60% lymphocytes and 40% polymorphs, and protein content of 100 mg%; glucose was 60 mg%. The diagnosis was confirmed by culture on Sabouraud's Dextrose agar. The patient was treated successfully with intensive Amphotericin B (1 mg/kg), for two weeks, followed by oral Itraconazole (400 mg daily), for a period of two months. The patient was started on anti retroviral therapy. He did not show any relapse of the symptoms when the last follow up was done six months after the date of discharge. PMID:19893682

[Effect of Invasive Herb Species on the Structure of Soil Yeast Complexes in Mixed Forests Exemplified by Impatiens parviflora DC].

PubMed

Glushakova, A M; Kachalkin, A V; Chernov, I Yu

2015-01-01

Yeast abundance and diversity in a mixed forest sod-podzol soil under Impatiens parviflora DC plants was studied in comparison with unimpaired aboriginal herbaceous plants typical of the Mid-Russian secondary, after-forest meadow. The study was carried out throughout the vegetation period. Standard microbiological plating techniques revealed 36 yeast species. Typical pedobiotic (Cryptococcus podzolicus, Wickerhamomyces anomalus) and eurybiotic yeast species (Rhodotorula mucilaginosa) predominated in both biotopes. The relative abundance of the autochthonous soil yeast species Cryptococcus podzolicus was higher in the soil under aboriginal herbs than under Impatiens parviflora. Sites with aboriginal vegetation were also characterized by high abundance of the pedogamous species Schwanniomyces castelli and Torulaspora delbrueckii. The share of yeastlike Trichosporon fungi with high hydrolytic activity was considerably higher under adventitious plants Impatiens parviflora, as well as in the previously studied soil under Heracleum sosnowskyi.

Immobilized Rhodotorula mucilaginosa: a novel urethanase-producing strain for degrading ethyl carbamate.

PubMed

Wu, Qun; Zhao, Yamin; Wang, Dong; Xu, Yan

2013-12-01

Rhodotorula mucilaginosa, producing the ethyl carbamate (EC)-degrading enzyme, urethanase, was newly isolated from the Chinese rice wine making process. It removed 80 % of EC when it was incubated with 5.0 g/L EC. It grew and stably produced urethanase, with pH ranging from 7.0 to 3.0. In addition, urethanase production by R. mucilaginosa was systematically optimized. Glucose, yeast extract, peptone, and inoculum size were selected with the Plackett-Burman design. They were further optimized via uniform design and determined to be 24.6 g/L, 2.5 g/L, 23.1 g/L, and 65.8 mL/500 mL, respectively. Urethanase activity reached 4,340.0 U/L in the optimal fermentation condition. Furthermore, cell immobilization of R. mucilaginosa in calcium alginate/chitosan was applied to improve cell resistance to environmental stresses. The immobilized cells removed 51.6 % of EC in commercial rice wine, which was 10 times more than that of the free cells. It indicated that the immobilized R. mucilaginosa was effective for degrading EC.

Mixed Infection of Respiratory Tract in a Dog Caused by Rhodotorula mucilaginosa and Trichosporon jirovecii: A Case Report.

PubMed

Biegańska, Małgorzata J; Rzewuska, Magdalena; Dąbrowska, Iwona; Malewska-Biel, Bożena; Ostrzeszewicz, Magdalena; Dworecka-Kaszak, Bożena

2018-06-01

This report describes the isolation of two environmental fungi: Rhodotorula mucilaginosa and Trichosporon jirovecii accompanied by Pseudomonas aeruginosa and Escherichia coli from a dog with bronchotracheitis. All microorganisms were isolated routinely from a mucopurulent discharge, obtained during bronchoscopy from laryngotracheal area. The initial identification of yeasts was confirmed by API Candida and by molecular analysis of internal transcribed spacer region. Administered antimicrobial treatment with Marbofloxacin and Canizol has brought the improvement in the dogs' health status. The final results of control mycological culture were negative. Most probably underlying hypothyroidism and the use of steroids were the factors predisposing this patient to opportunistic infection of mixed aetiology. As far as we are concerned, this is the first case of dogs' respiratory tract infection caused by R. mucilaginosa and T. jirovecii.

Characterization and Dynamic Behavior of Wild Yeast during Spontaneous Wine Fermentation in Steel Tanks and Amphorae

PubMed Central

Díaz, Cecilia; Molina, Ana María; Nähring, Jörg; Fischer, Rainer

2013-01-01

We studied the dynamic behavior of wild yeasts during spontaneous wine fermentation at a winery in the Valais region of Switzerland. Wild yeasts in the winery environment were characterized using a PCR-RFLP method. Up to 11 different yeast species were isolated from the vineyard air, whereas only seven were recovered from the grapes surface. We initially investigated a cultureindependent method in pilot-scale steel fermentation tanks and found a greater diversity of yeasts in the musts from two red grape varieties compared to three white grape varieties. We found that the yeasts Metschnikowia pulcherrima, Rhodotorula mucilaginosa, Pichia kluyveri, P. membranifaciens and Saccharomyces cerevisiae remained active at the end of the fermentation. We also studied the dynamic behavior of yeasts in Qvevris for the first time using a novel, highlysensitive quantitative real-time PCR method. We found that non-Saccharomyces yeasts were present during the entire fermentation process, with R. mucilaginosa and P. anomala the most prominent species. We studied the relationship between the predominance of different species and the output of the fermentation process. We identified so-called spoilage yeasts in all the fermentations, but high levels of acetic acid accumulated only in those fermentations with an extended lag phase. PMID:23738327

The assessment of epiphytic yeast diversity in sugarcane phyllosphere in Thailand by culture-independent method.

PubMed

Nasanit, Rujikan; Tangwong-O-Thai, Apirat; Tantirungkij, Manee; Limtong, Savitree

2015-12-01

The diversity of epiphytic yeasts from sugarcane (Saccharum officinarum Linn.) phyllospheres in Thailand was investigated by culture-independent method based on the analysis of the D1/D2 domains of the large subunit rRNA gene sequences. Forty-five samples of sugarcane leaf were collected randomly from ten provinces in Thailand. A total of 1342 clones were obtained from 45 clone libraries. 426 clones (31.7 %) were closely related to yeast strains in the GenBank database, and they were clustered into 31 operational taxonomic units (OTUs) with a similarity threshold of 99 %. All OTU sequences were classified in phylum Basidiomycota which were closely related to 11 yeast species in seven genera including Cryptococcus flavus, Hannaella coprosmaensis, Rhodotorula taiwanensis, Jaminaea angkoreiensis, Malassezia restricta, Pseudozyma antarctica, Pseudozyma aphidis, Pseudozyma hubeiensis, Pseudozyma prolifica, Pseudozyma shanxiensis, and Sporobolomyces vermiculatus. The most predominant yeasts detected belonged to Ustilaginales with 89.4 % relative frequency and the prevalent yeast genus was Pseudozyma. However, the majority were unable to be identified as known yeast species and these sequences may represent the sequences of new yeast taxa. In addition, The OTU that closely related to P. prolifica was commonly detected in sugarcane phyllosphere. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Engineering an efficient and tight D-amino acid-inducible gene expression system in Rhodosporidium/Rhodotorula species.

PubMed

Liu, Yanbin; Koh, Chong Mei John; Ngoh, Si Te; Ji, Lianghui

2015-10-26

Rhodosporidium and Rhodotorula are two genera of oleaginous red yeast with great potential for industrial biotechnology. To date, there is no effective method for inducible expression of proteins and RNAs in these hosts. We have developed a luciferase gene reporter assay based on a new codon-optimized LUC2 reporter gene (RtLUC2), which is flanked with CAR2 homology arms and can be integrated into the CAR2 locus in the nuclear genome at >90 % efficiency. We characterized the upstream DNA sequence of a D-amino acid oxidase gene (DAO1) from R. toruloides ATCC 10657 by nested deletions. By comparing the upstream DNA sequences of several putative DAO1 homologs of Basidiomycetous fungi, we identified a conserved DNA motif with a consensus sequence of AGGXXGXAGX11GAXGAXGG within a 0.2 kb region from the mRNA translation initiation site. Deletion of this motif led to strong mRNA transcription under non-inducing conditions. Interestingly, DAO1 promoter activity was enhanced about fivefold when the 108 bp intron 1 was included in the reporter construct. We identified a conserved CT-rich motif in the intron with a consensus sequence of TYTCCCYCTCCYCCCCACWYCCGA, deletion or point mutations of which drastically reduced promoter strength under both inducing and non-inducing conditions. Additionally, we created a selection marker-free DAO1-null mutant (∆dao1e) which displayed greatly improved inducible gene expression, particularly when both glucose and nitrogen were present in high levels. To avoid adding unwanted peptide to proteins to be expressed, we converted the original translation initiation codon to ATC and re-created a translation initiation codon at the start of exon 2. This promoter, named P DAO1-in1m1 , showed very similar luciferase activity to the wild-type promoter upon induction with D-alanine. The inducible system was tunable by adjusting the levels of inducers, carbon source and nitrogen source. The intron 1-containing DAO1 promoters coupled with a DAO1 null

Degradation of hop bitter acids by fungi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huszcza, Ewa; Bartmanska, Agnieszka; Aniol, Miroslaw

2008-07-01

Nine fungal strains related to: Trametes versicolor, Nigrospora oryzae, Inonotus radiatus, Crumenulopsis sororia, Coryneum betulinum, Cryptosporiopsis radicicola, Fusarium equiseti, Rhodotorula glutinis and Candida parapsilosis were tested for their ability to degrade humulones and lupulones. The best results were obtained for T. versicolor culture, in which humulones and lupulones were fully degraded after 4 days of incubation in the dark or after 36 h in the light. The experiments were performed on a commercial hop extract and on sterilized spent hops.

Rhodotorula minuta fungemia in a ewe lamb.

PubMed

Chitko-McKown, C G; Leymaster, K A; Heaton, M P; Griffin, D D; Veatch, J K; Jones, S A; Clawson, M L

2014-12-01

An 8-month-old crossbred ewe, normal upon physical examination, was humanely euthanized for tissue collection. After approximately 3 weeks in tissue culture, fungi began budding out of cells obtained from the choroid plexus. After an additional 3 weeks, budding was observed in kidney cell cultures and eventually in monocyte cultures as well. Serum from the lamb was submitted to the Veterinary Diagnostic Laboratory at Colorado State University for fungal diagnosis and was found negative for Aspergillus, Blastomyces, Coccidioidomycosis and Histoplasmosis. DNA was isolated from fungi collected from tissue culture supernatants and used in a set of pan-fungal PCR assays with DNA from Candida acting as a positive control. PCR products were sequenced and BLAST analysis performed. The unknown fungal sequence aligned with 100% identity to Rhodotorula minuta an emerging opportunistic pathogen. Samples were submitted to The Fungal Testing Laboratory at The University of Texas Health Science Center at San Antonio for additional validation. We believe this to be the first report of Rhodotorula fungemia in a sheep in the United States. © 2013 Blackwell Verlag GmbH.

Study on the effects of near-future ocean acidification on marine yeasts: a microcosm approach

NASA Astrophysics Data System (ADS)

Krause, Evamaria; Wichels, Antje; Erler, René; Gerdts, Gunnar

2013-12-01

Marine yeasts play an important role in biodegradation and nutrient cycling and are often associated with marine flora and fauna. They show maximum growth at pH levels lower than present-day seawater pH. Thus, contrary to many other marine organisms, they may actually profit from ocean acidification. Hence, we conducted a microcosm study, incubating natural seawater from the North Sea at present-day pH (8.10) and two near-future pH levels (7.81 and 7.67). Yeasts were isolated from the initial seawater sample and after 2 and 4 weeks of incubation. Isolates were classified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and representative isolates were identified by partial sequencing of the large subunit rRNA gene. From the initial seawater sample, we predominantly isolated a yeast-like filamentous fungus related to Aureobasidium pullulans, Cryptococcus sp., Candida sake, and various cold-adapted yeasts. After incubation, we found more different yeast species at near-future pH levels than at present-day pH. Yeasts reacting to low pH were related to Leucosporidium scottii, Rhodotorula mucilaginosa, Cryptococcus sp., and Debaryomyces hansenii. Our results suggest that these yeasts will benefit from seawater pH reductions and give a first indication that the importance of yeasts will increase in a more acidic ocean.

Inactivation of bacterial quorum sensing signals N-acyl homoserine lactones is widespread in yeasts.

PubMed

Leguina, Ana Carolina Del V; Nieto, Carolina; Pajot, Hipólito M; Bertini, Elisa V; Mac Cormack, Walter; Castellanos de Figueroa, Lucía I; Nieto-Peñalver, Carlos G

2018-01-01

The inactivation of quorum sensing signals, a phenomenon known as quorum quenching, has been described in diverse microorganisms, though it remains almost unexplored in yeasts. Beyond the well-known properties of these microorganisms for the industry or as eukaryotic models, the role of yeasts in soil or in the inner tissues of a plant is largely unknown. In this report, the wider survey of quorum quenching activities in yeasts isolated from Antarctic soil and the inner tissues of sugarcane, a tropical crop, is presented. Results show that, independently of their niche, quorum quenching activities are broadly present in unicellular fungi. Although yeasts showing a broad range of quorum quenching activity are present in the two niches, at the same time specific AHL inactivation profiles can also be found. Furthermore, yeasts from both sampling sites show quorum quenching activities compatible with lactonase-like and acylase-like inactivations of AHLs. Interestingly, the characterization of Rhodotorula mucilaginosa 7Apo1 showed that the presence of a particular AHL does not interfere with the quenching of a second molecule. Evidence suggests that yeasts could play a role in the modulation of the quorum sensing activity of bacteria. The relationship among phylogeny, sampling sites and yeast quorum quenching activities of the isolates is analyzed. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Optimizing pressurized liquid extraction of microbial lipids using the response surface method.

PubMed

Cescut, J; Severac, E; Molina-Jouve, C; Uribelarrea, J-L

2011-01-21

Response surface methodology (RSM) was used for the determination of optimum extraction parameters to reach maximum lipid extraction yield with yeast. Total lipids were extracted from oleaginous yeast (Rhodotorula glutinis) using pressurized liquid extraction (PLE). The effects of extraction parameters on lipid extraction yield were studied by employing a second-order central composite design. The optimal condition was obtained as three cycles of 15 min at 100°C with a ratio of 144 g of hydromatrix per 100 g of dry cell weight. Different analysis methods were used to compare the optimized PLE method with two conventional methods (Soxhlet and modification of Bligh and Dyer methods) under efficiency, selectivity and reproducibility criteria thanks to gravimetric analysis, GC with flame ionization detector, High Performance Liquid Chromatography linked to Evaporative Light Scattering Detector (HPLC-ELSD) and thin-layer chromatographic analysis. For each sample, the lipid extraction yield with optimized PLE was higher than those obtained with referenced methods (Soxhlet and Bligh and Dyer methods with, respectively, a recovery of 78% and 85% compared to PLE method). Moreover, the use of PLE led to major advantages such as an analysis time reduction by a factor of 10 and solvent quantity reduction by 70%, compared with traditional extraction methods. Copyright © 2010 Elsevier B.V. All rights reserved.

Beta-carotene-rich carotenoid-protein preparation and exopolysaccharide production by Rhodotorula rubra GED8 grown with a yogurt starter culture.

PubMed

Frengova, Ginka I; Simova, Emilina D; Beshkova, Dora M

2006-01-01

The underlying method for obtaining a beta-carotene-rich carotenoid-protein preparation and exopolysaccharides is the associated cultivation of the carotenoid-synthesizing lactose-negative yeast strain Rhodotorula rubra GED8 with the yogurt starter culture (Lactobacillus bulgaricus 2-11 + Streptococcus thermophilus 15HA) in whey ultrafiltrate (45 g lactose/l) with a maximum carotenoid yield of 13.37 mg/l culture fluid on the 4.5th day. The chemical composition of the carotenoid-protein preparation has been identified. The respective carotenoid and protein content is 497.4 microg/g dry cells and 50.3% per dry weight, respectively. An important characteristic of the carotenoid composition is the high percentage (51.1%) of beta-carotene (a carotenoid pigment with the highest provitamin A activity) as compared to 12.9% and 33.7%, respectively, for the other two individual pigments--torulene and torularhodin. Exopolysaccharides (12.8 g/l) synthesized by the yeast and lactic acid cultures, identified as acid biopolymers containing 7.2% glucuronic acid, were isolated in the cell-free supernatant. Mannose, produced exclusively by the yeast, predominated in the neutral carbohydrate biopolymer component (76%). The mixed cultivation of R. rubra GED8 with the yogurt starter (L. bulgaricus 2-11 + S. thermophilus 15HA) in ultrafiltrate under conditions of intracellular production of maximum amount of carotenoids and exopolysaccharides synthesis enables combined utilization of the culture fluid from the fermentation process.

Rhodotorula mucilaginosa associacted meningitis: A subacute entity with high mortality. Case report and review

PubMed Central

Tsiodras, Sotirios; Papageorgiou, Sotirios; Meletiadis, Joseph; Tofas, Polydoros; Pappa, Vasiliki; Panayiotides, John; Karakitsos, Petros; Armaganidis, Apostolos; Petrikkos, George

2014-01-01

A fatal case of meningitis due to Rhodotorula mucilaginosa in a 28 year-old HIV-negative male with a history of Hodgkin lymphoma who underwent salvage chemotherapy is presented. Reviewing the literature we identified 13 cases with central nervous system infection due Rhodotorula spp. The disease usually occurs in HIV negative immunosupressed middle-aged males. It takes the form of subacute or chronic meningitis accompanied by fever with an overall mortality of 46.2% despite antifungal therapy. PMID:25379400

Yeasts from Marine and Estuarine Waters with Different Levels of Pollution in the State of Rio de Janeiro, Brazil

PubMed Central

Hagler, Allen N.; Mendonça-Hagler, Leda C.

1981-01-01

Yeast counts were made at 24 marine and estuarine sites in the vicinity of Rio de Janeiro, Brazil. Mean salinities of estuarine sites ranged from 14.2 to 27.4‰, and mean temperatures ranged from 25 to 28°C. Total coliform counts varied from 80% above 100,000 colony-forming units (CFU)/100 ml at heavily polluted sites to 100% below 100 CFU/100 ml at unpolluted sites. Total yeast counts above 100 CFU/100 ml were typical of heavily and moderately polluted water but atypical of lightly polluted and unpolluted water. Mean total yeast counts were 2,880 CFU/100 ml for heavily polluted sites, 202 CFU/100 ml for moderately polluted sites, and 3 CFU/100 ml for lightly polluted and unpolluted sites. Total yeast counts had a positive response to increased pollution levels, and Candida krusei and phenotypically similar yeasts as a group were prevalent in polluted estuarine water but rare in unpolluted seawater. The 549 strains of yeasts and yeast-like organisms isolated were grouped into 67 species, of which the 21 most prevalent made up 86% of the total yeast population. The prevalent genera in the polluted estuary were Candida, Rhodotorula, Torulopsis, Hanseniaspora, Debaryomyces, and Trichosporon. PMID:16345683

Virulence and antifungal therapy of murine disseminated infection by Rhodotorula mucilaginosa.

PubMed

Thomson, Pamela; López-Fernández, Loida; Guarro, Josep; Capilla, Javier

2017-09-01

Rhodotorula infections have emerged in recent years causing mainly fungemia associated to high mortality. We have evaluated the in vitro activity of nine antifungal drugs against four clinical strains of Rhodotorula mucilaginosa, being amphotericin B, voriconazole and posaconazole the most active compounds. The experimental virulence of this fungus and the efficacy of the three mentioned drugs were evaluated in disseminated infections in neutropenic mice. Infection resulted in a high fungal load in all the organs studied without evident particular tropism. All treated animals showed reduced burden respect to the control in a strain dependent manner being voriconazole slightly superior to posaconazole and amphotericin B. Copyright © 2017 Elsevier Inc. All rights reserved.

Catheter-Associated Rhodotorula mucilaginosa Fungemia in an Immunocompetent Host

PubMed Central

Kim, Hyun Ah; Hyun, Miri

2013-01-01

Rhodotorula species live in the environment, but can also colonize human epithelium, as well as respiratory, and gastrointestinal tracts. Reports of infection, especially in the past 2 decades, have noted increasing numbers of Rhodotorula infections, particularly in immunocompromised hosts, leading it to be considered emerging opportunistic pathogen. The major risk factors for infection were prolonged use of central venous catheters in patients with hematological and solid malignancies who are taking corticosteroids or cytotoxic drugs. Herein, we report a case of catheter-associated fungemia due to R. mucilaginosa in an immunocompetent host. The patient was admitted to the intensive care unit with mechanical ventilation for treatment of community-acquired pneumonia. After 10 days, the patient developed new-onset fever confirmed to be a result of catheter-associated blood-stream infection by R. mucilaginosa. It was successfully treated by catheter removal and intravenous amphotericin B. PMID:24396637

The Marine Fungi Rhodotorula sp. (Strain CNYC4007) as a Potential Feed Source for Fish Larvae Nutrition

PubMed Central

Barra, M.; Llanos-Rivera, A.; Cruzat, F.; Pino-Maureira, N.; González-Saldía, R. R.

2017-01-01

Fish oil is used in the production of feed for cultured fish owing to its high polyunsaturated fatty acid content (PUFA). The over-exploitation of fisheries and events like “El Niño” are reducing the fish oil supply. Some marine microorganisms are considered potentially as alternative fatty acid sources. This study assesses a strain of Rhodotorula sp. (strain CNYC4007; 27% docosahexaenoic acid (DHA) of total fatty acids), as feed for fish larvae. The total length and ribonucleic acid (RNA)/deoxyribonucleic acid (DNA) ratio of Danio rerio larvae was determined at first feeding at six and 12 days old (post-yolk absorption larvae). Larvae fed with microencapsulated Rhodotorula sp. CNYC4007 had a significantly higher RNA/DNA ratio than control group (C1). At six days post-yolk absorption group, the RNA/DNA ratio of larvae fed with Rhodotorula sp. bioencapsulated in Brachionus sp. was significantly higher than control group fed with a commercial diet high in DHA (C2-DHA). Finally, at 12 days post-yolk absorption, the RNA/DNA ratio was significantly higher in larvae fed with Rhodotorula sp. CNYC4007 and C2-DHA (both bioencapsulated in Artemia sp. nauplii) than in control group (C1). These results suggest that Rhodotorula sp. CNYC4007 can be an alternative source of DHA for feeding fish at larval stage, providing a sustainable source of fatty acids. PMID:29194350

Polyphenolic substrates and dyes degradation by yeasts from 25 de Mayo/King George Island (Antarctica).

PubMed

Rovati, José I; Pajot, Hipólito F; Ruberto, Lucas; Mac Cormack, Walter; Figueroa, Lucía I C

2013-11-01

Antarctica offers a range of extreme climatic conditions, such as low temperatures, high solar radiation and low nutrient availability, and constitutes one of the harshest environments on Earth. Despite that, it has been successfully colonized by ’cold-loving’ fungi, which play a key role in decomposition cycles in cold ecosystems. However, knowledge about the ecological role of yeasts in nutrient or organic matter recycling/mineralization remains highly fragmentary. The aim of this work was to study the yeast microbiota in samples collected on 25 de Mayo/King George Island regarding the scope of their ability to degrade polyphenolic substrates such as lignin and azo dyes. Sixty-one yeast isolates were obtained from 37 samples, including soil, rocks, wood and bones. Molecular analyses based on rDNA sequences revealed that 35 yeasts could be identified at the species level and could be classified in the genera Leucosporidiella, Rhodotorula, Cryptococcus, Bullera and Candida. Cryptococcus victoriae was by far the most ubiquitous species. In total, 33% of the yeast isolates examined showed significant activity for dye decolorization, 25% for laccase activity and 38% for ligninolytic activity. Eleven yeasts did not show positive activity in any of the assays performed and no isolates showed positive activity across all tested substrates. A high diversity of yeasts were isolated in this work, possibly including undescribed species and conspicuous Antarctic yeasts, most of them belonging to oligotrophic, slow-growing and metabolically diverse basidiomycetous genera.

Characterization of pectinase activity for enology from yeasts occurring in Argentine Bonarda grape.

PubMed

Merín, María Gabriela; Martín, María Carolina; Rantsiou, Kalliopi; Cocolin, Luca; de Ambrosini, Vilma Inés Morata

2015-01-01

Pectinolytic enzymes are greatly important in winemaking due to their ability to degrade pectic polymers from grape, contributing to enhance process efficiency and wine quality. This study aimed to analyze the occurrence of pectinolytic yeasts during spontaneous fermentation of Argentine Bonarda grape, to select yeasts that produce extracellular pectinases and to characterize their pectinolytic activity under wine-like conditions. Isolated yeasts were grouped using PCR-DGGE and identified by partial sequencing of 26S rRNA gene. Isolates comprised 7 genera, with Aureobasidium pullulans as the most predominant pectinolytic species, followed by Rhodotorula dairenensis and Cryptococcus saitoi. No pectinolytic activity was detected among ascomycetous yeasts isolated on grapes and during fermentation, suggesting a low occurrence of pectinolytic yeast species in wine fermentation ecosystem. This is the first study reporting R. dairenensis and Cr. saitoi species with pectinolytic activity. R. dairenensis GM-15 produced pectinases that proved to be highly active at grape pH, at 12 °C, and under ethanol and SO2 concentrations usually found in vinifications (pectinase activity around 1.1 U/mL). This strain also produced cellulase activity at 12 °C and pH 3.5, but did not produce β-glucosidase activity under these conditions. The strain showed encouraging enological properties for its potential use in low-temperature winemaking.

Characterization of pectinase activity for enology from yeasts occurring in Argentine Bonarda grape

PubMed Central

Merín, María Gabriela; Martín, María Carolina; Rantsiou, Kalliopi; Cocolin, Luca; de Ambrosini, Vilma Inés Morata

2015-01-01

Pectinolytic enzymes are greatly important in winemaking due to their ability to degrade pectic polymers from grape, contributing to enhance process efficiency and wine quality. This study aimed to analyze the occurrence of pectinolytic yeasts during spontaneous fermentation of Argentine Bonarda grape, to select yeasts that produce extracellular pectinases and to characterize their pectinolytic activity under wine-like conditions. Isolated yeasts were grouped using PCR-DGGE and identified by partial sequencing of 26S rRNA gene. Isolates comprised 7 genera, with Aureobasidium pullulans as the most predominant pectinolytic species, followed by Rhodotorula dairenensis and Cryptococcus saitoi. No pectinolytic activity was detected among ascomycetous yeasts isolated on grapes and during fermentation, suggesting a low occurrence of pectinolytic yeast species in wine fermentation ecosystem. This is the first study reporting R. dairenensis and Cr. saitoi species with pectinolytic activity. R. dairenensis GM-15 produced pectinases that proved to be highly active at grape pH, at 12 °C, and under ethanol and SO2 concentrations usually found in vinifications (pectinase activity around 1.1 U/mL). This strain also produced cellulase activity at 12 °C and pH 3.5, but did not produce β-glucosidase activity under these conditions. The strain showed encouraging enological properties for its potential use in low-temperature winemaking. PMID:26413065

Differentiation of Erwinia amylovora and Erwinia pyrifoliae strains with single nucleotide polymorphisms and by synthesis of dihydrophenylalanine.

PubMed

Gehring, I; Geider, K

2012-07-01

Fire blight has spread from North America to New Zealand, Europe, and the Mediterranean region. We were able to differentiate strains from various origins with a novel PCR method. Three Single Nucleotide Polymorphisms (SNPs) in the Erwinia amylovora genome were characteristic of isolates from North America and could distinguish them from isolates from other parts of the world. They were derived from the galE, acrB, and hrpA genes of strains Ea273 and Ea1/79. These genes were analyzed by conventional PCR (cPCR) and quantitative PCR (qPCR) with differential primer annealing temperatures. North-American E. amylovora strains were further differentiated according to their production of L: -2,5-dihydrophenylalanine (DHP) as tested by growth inhibition of the yeast Rhodotorula glutinis. E. amylovora fruit tree (Maloideae) and raspberry (rubus) strains were also differentiated by Single Strand Conformational Polymorphism analysis. Strains from the related species Erwinia pyrifoliae isolated in Korea and Japan were all DHP positive, but were differentiated from each other by SNPs in the galE gene. Differential PCR is a rapid and simple method to distinguish E. amylovora as well as E. pyrifoliae strains according to their geographical origin.

Bioprospection of cold-adapted yeasts with biotechnological potential from Antarctica.

PubMed

Martorell, María Martha; Ruberto, Lucas Adolfo Mauro; Fernández, Pablo Marcelo; Castellanos de Figueroa, Lucía Inés; Mac Cormack, Walter Patricio

2017-06-01

The aim of this study was to investigate the ability to produce extracellular hydrolytic enzymes at low temperature of yeasts isolated from 25 de Mayo island, Antarctica, and to identify those exhibiting one or more of the evaluated enzymatic activities. A total of 105 yeast isolates were obtained from different samples and 66 were identified. They belonged to 12 basidiomycetous and four ascomycetous genera. Most of the isolates were ascribed to the genera Cryptococcus, Mrakia, Cystobasidium, Rhodotorula, Gueomyces, Phenoliferia, Leucosporidium, and Pichia. Results from enzymes production at low temperatures revealed that the Antarctic environment contains metabolically diverse cultivable yeasts, which represent potential tools for biotechnological applications. While most the isolates proved to produce 2-4 of the investigated exoenzymes, two of them evidenced the six evaluated enzymatic activities: Pichia caribbica and Guehomyces pullulans, which were characterized as psycrotolerant and psycrophilic, respectively. In addition, P. caribbica could assimilate several n-alkanes and diesel fuel. The enzyme production profile and hydrocarbons assimilation capacity, combined with its high level of biomass production and the extended exponential growth phase make P. caribbica a promising tool for cold environments biotechnological purposes in the field of cold-enzymes production and oil spills bioremediation as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The diversity and antifungal susceptibility of the yeasts isolated from coconut water and reconstituted fruit juices in Brazil.

PubMed

Maciel, Natália O P; Piló, Fernanda B; Freitas, Larissa F D; Gomes, Fátima C O; Johann, Susana; Nardi, Regina M D; Lachance, Marc-André; Rosa, Carlos A

2013-01-01

The aims of this study were to characterise the yeasts present in the reconstituted fruit juices and coconut water extracted with "coconut machines", both collected from commercial outlets in a Brazilian city, and to investigate the antifungal resistance of isolates from these beverages that were able to grow at 37°C. The yeast population counts in the coconut water samples ranged from 1.7 to >6.5logcfu/ml, and in the reconstituted fruit juices, the counts ranged from 1.5 to >5.5logcfu/ml. Aureobasidium pullulans, Candida boidinii, Candidaintermedia, Candidaoleophila, Candidaparapsilosis, Candidasantamariae, Candidatropicalis, Clavispora lusitaniae, Kloeckera apis, Lachancea fermentati, Pichia fermentans and Rhodotorula mucilaginosa were the most frequent species isolated from these beverages. At least 18 yeast species isolated from these beverages have been reported as opportunistic pathogens. Eight yeast isolates were resistant to fluconazole, seven were resistant to itraconazole, and 26 to amphotericin B. Some yeast species were resistant to more than one of the antifungal drugs tested. Two isolates of C. tropicalis from the reconstituted fruit juices exhibited resistance to all three drugs. The presence of yeast strains that are resistant to commonly used antifungal drugs suggests a potential risk, at least to immunocompromised individuals who consume these beverages. Copyright © 2012 Elsevier B.V. All rights reserved.

Diversity of endophytic yeasts from sweet orange and their localization by scanning electron microscopy.

PubMed

Gai, Cláudia Santos; Lacava, Paulo Teixeira; Maccheroni, Walter; Glienke, Chirlei; Araújo, Welington Luiz; Miller, Thomas Albert; Azevedo, João Lúcio

2009-10-01

Endophytes are microorganisms that colonize plant tissues internally without causing harm to the host. Despite the increasing number of studies on sweet orange pathogens and endophytes, yeast has not been described as a sweet orange endophyte. In the present study, endophytic yeasts were isolated from sweet orange plants and identified by sequencing of internal transcribed spacer (ITS) rRNA. Plants sampled from four different sites in the state of São Paulo, Brazil exhibited different levels of CVC (citrus variegated chlorosis) development. Three citrus endophytic yeasts (CEYs), chosen as representative examples of the isolates observed, were identified as Rhodotorula mucilaginosa, Pichia guilliermondii and Cryptococcus flavescens. These strains were inoculated into axenic Citrus sinensis seedlings. After 45 days, endophytes were re-isolated in populations ranging from 10(6) to 10(9) CFU/g of plant tissue, but, in spite of the high concentrations of yeast cells, no disease symptoms were observed. Colonized plant material was examined by scanning electron microscopy (SEM), and yeast cells were found mainly in the stomata and xylem of plants, reinforcing their endophytic nature. P. guilliermondii was isolated primarily from plants colonized by the causal agent of CVC, Xylella fastidiosa. The supernatant from a culture of P. guilliermondii increased the in vitro growth of X. fastidiosa, suggesting that the yeast could assist in the establishment of this pathogen in its host plant and, therefore, contribute to the development of disease symptoms. Copyright 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Monitoring of Yeast Communities and Volatile Flavor Changes During Traditional Korean Soy Sauce Fermentation.

PubMed

Song, Young-Ran; Jeong, Do-Youn; Baik, Sang-Ho

2015-09-01

Flavor development in soy sauce is significantly related to the diversity of yeast species. Due to its unique fermentation with meju, the process of making Korean soy sauce gives rise to a specific yeast community and, therefore, flavor profile; however, no detailed analysis of the identifying these structure has been performed. Changes in yeast community structure during Korean soy sauce fermentation were examined using both culture-dependent and culture-independent methods with simultaneous analysis of the changes in volatile compounds by GC-MS analysis. During fermentation, Candida, Pichia, and Rhodotorula sp. were the dominant species, whereas Debaryomyces, Torulaspora, and Zygosaccharomyces sp. were detected only at the early stage. In addition, Cryptococcus, Microbotryum, Tetrapisispora, and Wickerhamomyces were detected as minor strains. Among the 62 compounds identified in this study, alcohols, ketones, and pyrazines were present as the major groups during the initial stages, whereas the abundance of acids with aldehydes increased as the fermentation progressed. Finally, the impacts of 10 different yeast strains found to participate in fermentation on the formation of volatile compounds were evaluated under soy-based conditions. It was revealed that specific species produced different profiles of volatile compounds, some of which were significant flavor contributors, especially volatile alcohols, aldehydes, esters, and ketones. © 2015 Institute of Food Technologists®

Cocoa butter-like lipid production ability of non-oleaginous and oleaginous yeasts under nitrogen-limited culture conditions.

PubMed

Wei, Yongjun; Siewers, Verena; Nielsen, Jens

2017-05-01

Cocoa butter (CB) extracted from cocoa beans is the main raw material for chocolate production. However, growing chocolate demands and limited CB production has resulted in a shortage of CB supply. CB is mainly composed of three different kinds of triacylglycerols (TAGs), POP (C16:0-C18:1-C16:0), POS (C16:0-C18:1-C18:0), and SOS (C18:0-C18:1-C18:0). The storage lipids of yeasts, mainly TAGs, also contain relative high-level of C16 and C18 fatty acids and might be used as CB-like lipids (CBL). In this study, we cultivated six different yeasts, including one non-oleaginous yeast strain, Saccharomyces cerevisiae CEN.PK113-7D, and five oleaginous yeast strains, Trichosporon oleaginosus DSM11815, Rhodotorula graminis DSM 27356, Lipomyces starkeyi DSM 70296, Rhodosporidium toruloides DSM 70398, and Yarrowia lipolytica CBS 6124, in nitrogen-limited medium and compared their CBL production ability. Under the same growth conditions, we found that TAGs were the main lipids in all six yeasts and that T. oleaginosus can produce more TAGs than the other five yeasts. Less than 3% of the total TAGs were identified as potential SOS in the six yeasts. However, T. oleaginosus produced 27.8% potential POP and POS at levels of 378 mg TAGs/g dry cell weight, hinting that this yeast may have potential as a CBL production host after further metabolic engineering in future.

Lipid production by pure and mixed cultures of Chlorella pyrenoidosa and Rhodotorula mucilaginosa isolated in Nuevo Leon, Mexico.

PubMed

Reyna-Martínez, Raúl; Gomez-Flores, Ricardo; López-Chuken, Ulrico J; González-González, Rosario; Fernández-Delgadillo, Sergio; Balderas-Rentería, Isaias

2015-01-01

Given the well-known environmental drawbacks of using fossil fuels, advances in the field of alternative energy have become a worldwide technological priority. Special interest has been focused on the production of biodiesel obtained from oleaginous microorganisms. In the present research, lipid production by two species, microalgae Chlorella pyrenoidosa and yeast Rhodotorula mucilaginosa was assessed, independently and in mixed culture to evaluate a possible synergy. Fatty acid analysis was performed by gas chromatography. Among pure and mixed cultures of both strains and several culturing conditions, the highest biomass and lipid productivity was obtained by C. pyrenoidosa (8.05 and 1.62 g/L, respectively). The results of this study showed that both strains used are in fact oleaginous strains as they were found to reach up to 20 % of lipids, in addition, lipids in both pure and mixed cultures were mainly of triglycerides (>90 %), composed of fatty acid chains between 16 and 18 carbons.

Microbial colonization of irradiated pathogenic yeast to catheter surfaces: Relationship between adherence, cell surface hydrophobicity, biofilm formation and antifungal susceptibility. A scanning electron microscope analysis.

PubMed

Farrag, Hala Abdallah; A-Karam El-Din, Alzahraa; Mohamed El-Sayed, Zeinab Galal; Abdel-Latifissa, Soheir; Kamal, Mona Mohamed

2015-06-01

Technological advances such as long-term indwelling catheters have created milieu in which infections are a major complication. Thus it is essential to be able to recognize, diagnose, and treat infections occurring in immunocompromised patients. Adherence assay and quantitation of biofilms was performed by a spectrophotometric method, hydrophobicity was evaluated by adhesion to p-xylene. The minimum inhibitory concentration (MIC) of Nystatin was carried out by a well dilution method. Out of 100 bladder cancer patients, 23 pathogenic yeast isolates were identified. The samples were taken from urinary catheters and urine collected from their attached drainage bags. Pathogenic yeast identified were species of Candida, Cryptococcus, Saccharomyces, Blastoschizomyces, Trichosporn, Hansenula, Prototheca and Rhodotorula. With the exception of Rhodotorula minuta, the yeast were sensitive to the antimycotic agent (Nystatin) used before and after in vitro gamma irradiation at 24.41 Gy as measured by a disc diffusion method. All tested yeast strains were slime producers and showed positive adherence reactions. There were considerable differences in adherence measurements after irradiation. An increase in adherence measurement values (using a spectrophotometric method) after irradiation were detected in four strains whereas eight other strains showed a reduction in their adherence reaction. The cell surface hydrophobicity (CSH) was evaluated by adhesion to p-xylene. Candida tropicalis showed a hydrophobic reaction with an increase in the cell surface hydrophobicity after irradiation. Scanning electron microscopy of irradiated C. tropicalis showed marked abnormalities in cell shape and size with significant reduction in adherence ability at the MIC level of Nystatin (4 μg/ml). More basic research at the level of pathogenesis and catheter substance is needed to design novel strategies to prevent fungal adherence and to inhibit biofilm formation.

Isolation and identification of yeast flora from genital tract in healthy female camels (Camelus dromedarius).

PubMed

Shokri, Hojjatollah; Khosravi, Alireza; Sharifzadeh, Aghil; Tootian, Zahra

2010-07-29

Yeasts are commensal organisms found in the skin, genital and gastrointestinal tracts, and other mucosal sites in mammalians. The purposes of this study were to identify yeast flora and to determine the number of colony forming units (CFUs) in genital tract of healthy female dromedary camels, establishing their connection in both mated and unmated conditions. The samples were taken from different parts of genital tract including vestibule, vagina, cervix, uterine body, and uterine horns of 50 camels using sterilized cotton swabs. They were cultured onto Sabouraud glucose agar containing chloramphenicol and incubated at 30 degrees C for 7-10 days. A total of 454 yeast colonies were obtained from genital tract. Yeast isolates belonged to 8 genera: Candida (73.1%), Trichosporon (10.1%), Geotrichum (7.5%), Kluyveromyces (3.5%), Rhodotorula (2.4%), Aureobasidium (1.4%), Cryptococcus (1.1%) and Prototheca (0.8%). Among different Candida species, C. zeylanoides was the most common isolated species, representing significant difference with other Candida species (P<0.05). The mean number of yeasts found in the vestibule (46%) was significantly higher than the results obtained from other parts (P<0.05). In addition, the mean value of CFUs from unmated females (71.1%) was significantly higher than mated females (P<0.05). The results showed that C. zeylanoides was a common component of healthy camel females' genital mycoflora and the number of yeasts varied between mated and unmated females. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Yeast communities in Sphagnum phyllosphere along the temperature-moisture ecocline in the boreal forest-swamp ecosystem and description of Candida sphagnicola sp. nov.

PubMed

Kachalkin, Aleksey V; Yurkov, Andrey M

2012-06-01

The effects of the temperature-moisture factors on the phylloplane yeast communities inhabiting Sphagnum mosses were studied along the transition from a boreal forest to a swamp biotope at the Central Forest State Biosphere Reserve (Tver region, Russia). We tested the hypothesis that microclimatic parameters affect yeast community composition and structure even on a rather small spatial scale. Using a conventional plating technique we isolated and identified by molecular methods a total of 15 species of yeasts. Total yeast counts and species richness values did not depend on environmental factors, although yeast community composition and structure did. On average, Sphagnum in the swamp biotope supported a more evenly structured yeast community. Relative abundance of ascomycetous yeasts was significantly higher on swamp moss. Rhodotorula mucilaginosa dominated in the spruce forest and Cryptococcus magnus was more abundant in the swamp. Our study confirmed the low occurrence of tremellaceous yeasts in the Sphagnum phyllosphere. Of the few isolated ascomycetous yeast and yeast-like species, some were differentiated from hitherto known species in physiological tests and phylogenetic analyses. We describe one of them as Candida sphagnicola and designate KBP Y-3887(T) (=CBS 11774(T) = VKPM Y-3566(T) = MUCL 53590(T)) as the type strain. The new species was registered in MycoBank under MB 563443.

Evaluation of aroma enhancement for "Ecolly" dry white wines by mixed inoculation of selected Rhodotorula mucilaginosa and Saccharomyces cerevisiae.

PubMed

Wang, Xing-Chen; Li, Ai-Hua; Dizy, Marta; Ullah, Niamat; Sun, Wei-Xuan; Tao, Yong-Sheng

2017-08-01

To improve the aroma profile of Ecolly dry white wine, the simultaneous and sequential inoculations of selected Rhodotorula mucilaginosa and Saccharomyces cerevisiae were performed in wine making of this work. The two yeasts were mixed in various ratios for making the mixed inoculum. The amount of volatiles and aroma characteristics were determined the following year. Mixed fermentation improved both the varietal and fermentative aroma compound composition, especially that of (Z)-3-hexene-1-ol, nerol oxide, certain acetates and ethyls group compounds. Citrus, sweet fruit, acid fruit, berry, and floral aroma traits were enhanced by mixed fermentation; however, an animal note was introduced upon using higher amounts of R. mucilaginosa. Aroma traits were regressed with volatiles as observed by the partial least-square regression method. Analysis of correlation coefficients revealed that the aroma traits were the multiple interactions of volatile compounds, with the fermentative volatiles having more impact on aroma than varietal compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Screening and characterization of amylase and cellulase activities in psychrotolerant yeasts.

PubMed

Carrasco, Mario; Villarreal, Pablo; Barahona, Salvador; Alcaíno, Jennifer; Cifuentes, Víctor; Baeza, Marcelo

2016-02-19

Amylases and cellulases have great potential for application in industries such as food, detergent, laundry, textile, baking and biofuels. A common requirement in these fields is to reduce the temperatures of the processes, leading to a continuous search for microorganisms that secrete cold-active amylases and cellulases. Psychrotolerant yeasts are good candidates because they inhabit cold-environments. In this work, we analyzed the ability of yeasts isolated from the Antarctic region to grow on starch or carboxymethylcellulose, and their potential extracellular amylases and cellulases. All tested yeasts were able to grow with soluble starch or carboxymethylcellulose as the sole carbon source; however, not all of them produced ethanol by fermentation of these carbon sources. For the majority of the yeast species, the extracellular amylase or cellulase activity was higher when cultured in medium supplemented with glucose rather than with soluble starch or carboxymethylcellulose. Additionally, higher amylase activities were observed when tested at pH 5.4 and 6.2, and at 30-37 °C, except for Rhodotorula glacialis that showed elevated activity at 10-22 °C. In general, cellulase activity was high until pH 6.2 and between 22-37 °C, while the sample from Mrakia blollopis showed high activity at 4-22 °C. Peptide mass fingerprinting analysis of a potential amylase from Tetracladium sp. of about 70 kDa, showed several peptides with positive matches with glucoamylases from other fungi. Almost all yeast species showed extracellular amylase or cellulase activity, and an inducing effect by the respective substrate was observed in a minor number of yeasts. These enzymatic activities were higher at 30 °C in most yeast, with highest amylase and cellulase activity in Tetracladium sp. and M. gelida, respectively. However, Rh. glacialis and M. blollopis displayed high amylase or cellulase activity, respectively, under 22 °C. In this sense, these yeasts are interesting

Evaluation of the Relationship between the Incubation Time and Carotenoid Production in Rhodotorula Slooffiae and R. Mucilaginosa Isolated from Leather Tanning Wastewater 

PubMed Central

Sadat Naghavi, Farzaneh; Hanachi, Parichehr; Soudi, Mohammad Reza; Saboora, Azra; Ghorbani, Atefeh

2013-01-01

Objective(s): Carotenoids which are naturally synthesized by fungi such as yeasts can act as an antioxidant which is closely related to their ability to decrease the risk of a variety of degenerative diseases. In recent years, the increase of demand for carotenoids obtained from natural sources has promoted major efforts to improve carotenoid production from biological sources such as pigmented yeasts. The aim of this study was comparing incubation time and carotenoid production in Rhodotorula slooffiae and R. mucilaginosa isolated from leather tanning wastewater. Materials and Methods: To isolate the carotenoid pigment, cells were suspended in acetone and broken using a homogenizer, followed by centrifugation and separation of supernatant. In order to study the effect of incubation time, samples were held at 30 ˚С in a shaker at 150 rpm for 24, 48, 72, 96, and 120 hr. For analytical evaluation, pigments were measured spectrophotometrically at 450 nm using the extinction coefficient E1%450=2500. Results: The results showed that the content of total carotenoid in R. slooffiae was the highest when samples were incubated for 72 hr. Overall, R. mucilaginosa had more potential to produce carotenoid. The best incubation periods for R. slooffiae and R. mucilaginosa were 72 hr and 48 hr, respectively. Conclusion: It seemed that the maximum rate of total carotenoid was not directly associated with the maximum amount of cell biomass and the type of carotenoid and their relative amount may vary depending on genus of yeast. PMID:24379970

Evaluation of the Relationship between the Incubation Time and Carotenoid Production in Rhodotorula Slooffiae and R. Mucilaginosa Isolated from Leather Tanning Wastewater .

PubMed

Sadat Naghavi, Farzaneh; Hanachi, Parichehr; Soudi, Mohammad Reza; Saboora, Azra; Ghorbani, Atefeh

2013-10-01

Carotenoids which are naturally synthesized by fungi such as yeasts can act as an antioxidant which is closely related to their ability to decrease the risk of a variety of degenerative diseases. In recent years, the increase of demand for carotenoids obtained from natural sources has promoted major efforts to improve carotenoid production from biological sources such as pigmented yeasts. The aim of this study was comparing incubation time and carotenoid production in Rhodotorula slooffiae and R. mucilaginosa isolated from leather tanning wastewater. To isolate the carotenoid pigment, cells were suspended in acetone and broken using a homogenizer, followed by centrifugation and separation of supernatant. In order to study the effect of incubation time, samples were held at 30 ˚С in a shaker at 150 rpm for 24, 48, 72, 96, and 120 hr. For analytical evaluation, pigments were measured spectrophotometrically at 450 nm using the extinction coefficient E(1%) 450=2500. The results showed that the content of total carotenoid in R. slooffiae was the highest when samples were incubated for 72 hr. Overall, R. mucilaginosa had more potential to produce carotenoid. The best incubation periods for R. slooffiae and R. mucilaginosa were 72 hr and 48 hr, respectively. It seemed that the maximum rate of total carotenoid was not directly associated with the maximum amount of cell biomass and the type of carotenoid and their relative amount may vary depending on genus of yeast.

A differential medium for the enumeration of the spoilage yeast Zygosaccharomyces bailii in wine.

PubMed

Schuller, D; Côrte-Real, M; Leão, C

2000-11-01

A collection of yeasts, isolated mostly from spoiled wines, was used in order to develop a differential medium for Zygosaccharomyces bailii. The 118 selected strains of 21 species differed in their origin and resistance to preservatives and belonged to the genera Pichia, Torulaspora, Dekkera, Debaryomyces, Saccharomycodes, Issatchenkia, Kluyveromyces, Kloeckera, Lodderomyces, Schizosaccharomyces, Rhodotorula, Saccharomyces, and Zygosaccharomyces. The design of the culture medium was based on the different ability of the various yeast species to grow in a mineral medium with glucose and formic acid (mixed-substrate medium) as the only carbon and energy sources and supplemented with an acid-base indicator. By manipulating the concentration of the acid and the sugar it was possible to select conditions where only Z. bailii strains gave rise to alkalinization, associated with a color change of the medium (positive response). The final composition of the mixed medium was adjusted as a compromise between the percentage of recovery and selectivity for Z. bailii. This was accomplished by the use of pure or mixed cultures of the yeast strains and applying the membrane filtration methodology. The microbiological analysis of two samples of contaminated Vinho Verde showed that the new medium can be considered as a differential medium to distinguish Z. bailii from other contaminating yeasts, having potential application in the microbiological control of wines and probably other beverages and foods.

Presence and distribution of yeasts in the reproductive tract in healthy female horses.

PubMed

Azarvandi, A; Khosravi, A R; Shokri, H; Talebkhan Garoussi, M; Gharahgouzlou, F; Vahedi, G; Sharifzadeh, A

2017-09-01

Yeasts are commensal organisms found in the reproductive and gastrointestinal tracts, and on the skin and other mucosa in mammals. The purpose of this study was to isolate and identify yeast flora in the caudal reproductive tract in healthy female horses. Longitudinal study. A total of 453 samples were collected using double-guarded swabs from the vestibule, clitoral fossa and vagina in 151 horses. All samples were cultured on Sabouraud 4% dextrose agar and incubated at 35°C for 7-10 days. Isolates were identified according to their morphological characteristics and biochemical profiles. Yeast colonies were isolated from 60 (39.7%) of the 151 horses. The isolated yeasts belonged to nine genera, and included Candida spp. (53.2%), Cryptococcus spp. (12.2%), Saccharomyces spp. (10.5%), Geotrichum spp. (8.0%), Rhodotorula spp. (7.1%), Malassezia spp. (3.7%), Trichosporon spp. (2.6%), Kluyveromyces spp. (2.6%) and Sporothrix spp. (0.2%). Candida krusei (43.1%) was the most frequent Candida species isolated. There was a significant difference in prevalence between C. krusei and other Candida species (P<0.05). The vestibule contained more yeast isolates (48.0%) than the vagina (18.3%). The isolation of yeast colonies from multiparous females (76.8%) was significantly higher than from maiden mares (P<0.05). The study was limited by the difficulty of distinguishing between normal flora and potential pathogens. Candida spp., in particular C. krusei, represent important flora resident in the caudal reproductive tract in healthy female horses. This is particularly important in contexts that require the initiation of empirical treatment prior to the completion of culture results. © 2016 EVJ Ltd.

Biocontrol ability and putative mode of action of yeasts against Geotrichum citri-aurantii in citrus fruit.

PubMed

Ferraz, Luriany Pompeo; Cunha, Tatiane da; da Silva, Aline Caroline; Kupper, Katia Cristina

2016-01-01

Sour rot is a major postharvest disease of citrus fruit and is caused by the fungal pathogen Geotrichum citri-aurantii. A lack of chemicals certified for the control of this disease has led to the consideration of alternative methods and strategies, such as the use of yeasts as biocontrol agents. The purpose of the present study was to test the ability of yeasts isolated from leaves, flowers, fruit, and soil, and six Saccharomyces cerevisiae isolates to control citrus sour rot, to assess the mechanisms of action of the yeast isolates that were demonstrated to be effective for biocontrol, and to identify the most effective yeast isolates for the biocontrol of G. citri-aurantii. In in vivo assays, three yeast isolates (ACBL-23, ACBL-44, and ACBL-77) showed a potential for controlling sour rot in citrus fruits, both preventatively and curatively. Most of the eight yeast isolates that were assessed for a mechanism of action did not produce antifungal compounds in an amount sufficient to inhibit the growth of the pathogen. Additionally, nutrient competition among the yeast strains was not found to be a biocontrol strategy. Instead, killer activity and hydrolytic enzyme production were identified as the major mechanisms involved in the biocontrol activity of the yeasts. Isolates ACBL-23, ACBL-44, and ACBL-77, which controlled sour rot most effectively, were identified as Rhodotorula minuta, Candida azyma, and Aureobasidium pullulans, respectively. To our knowledge, this is the first report of the potential of C. azyma as a biological control agent against a postharvest pathogen and its ability to produce a killer toxin. Copyright © 2016 Elsevier GmbH. All rights reserved.

Burdock fructooligosaccharide enhances biocontrol of Rhodotorula mucilaginosa to postharvest decay of peaches.

PubMed

Zhang, Hongyin; Liu, Zhouyang; Xu, Baitian; Chen, Keping; Yang, Qiya; Zhang, Qiuyun

2013-10-15

The influence of adding burdock fructooligosaccharide (BFO) in the culture media on the efficacy of Rhodotorula mucilaginosa in controlling postharvest decay of peaches and its possible mode of action were investigated. The antagonistic activity of R. mucilaginosa to Rhizopus decay and blue mold decay of peaches was greatly enhanced through cultivation in the nutrient yeast dextrose agar (NYDA) medium amended with BFO at the concentration of 0.32%, compared with that cultivated in NYDB without BFO. R. mucilaginosa at 1×10(8) cells/mL cultivation in the NYDB media did not reduce the natural decay incidence of peaches, compared with the control after 30 d at 4 °C followed by 7d at 20 °C. However, R. mucilaginosa cultivation in the NYDB media amended with BFO at the concentration of 0.32% reduced the natural decay incidence of peaches. The population of R. mucilaginosa harvested from NYDB amended with BFO at 0.32% increased rapidly in peach wounds compared to that harvested from NYDB without BFO no matter peaches were stored at 20 °C or 4 °C. The activities of chitinase and β-1,3-glucanase of cell-free culture filtrate of R. mucilaginosa harvested from NYDB amended with BFO at 0.32% were higher than that at other concentrations and the control. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bioconversion of Xylan to triglycerides by oil-rich yeasts. [Cryptococcus albidus; Cryptococcus terricoluus; Trichosporon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fall, R.; Phelps, P.; Spindler, D.

A series of lipid-accumulating yeasts was examined for their potential to saccharify xylan and accumulate triglyceride. Of the genera tested, including Candida, Cryptococcus, Lipomyces, Rhodosporidium, Rhodotorula, and Trichosporon, only Crytococcus and Trichosporon isolates saccharified xylan. All of the strains could assimilate xylose and accumuate triglyceride under nitrogen-limiting conditions. Strains of Cryptococcus albidus were found to be especially useful for a one-step saccharification of xylan coupled to triglyceride synthesis. Crytococcus terricolus, a strain constitutive for lipid accumulation, lacked extracellular xylanase, but did assimilate xylose and xylobiose and was able to continuously convert xylan to triglyceride if the culture medium was supplementedmore » with xylanase. 22 references.« less

Evaluation of yeasts from Tibetan fermented products as agents for biocontrol of blue mold of Nashi pear fruits*

PubMed Central

Hu, Hao; Xu, Yang; Lu, Huang-ping; Xiao, Rui; Zheng, Xiao-dong; Yu, Ting

2015-01-01

A total of 20 strains of yeast isolated from Tibetan fermented products were screened for antagonism against blue mold of pear caused by Penicillium expansum. Six isolates that inhibited incidence of postharvest decay by 35% or more were selected for further screening. Among them, the most effective was Rhodotorula mucilaginosa. The results showed that washed cell suspensions of R. mucilaginosa yielded better antagonistic efficacy than unwashed cell-culture mixtures, cell-free culture filtrates, and autoclaved cell cultures. Biocontrol activity improved with increasing concentrations of incubated cells. The best concentration was 1×108 cells/ml, at which the incidence of decay was only 16.7% after 6 d of incubation. The germination of conidia of P. expansum in vitro was significantly inhibited by both washed cell-suspensions and unwashed cell-culture mixtures. Rapid colonization by yeast at different concentrations showed a relationship between yeast-cell concentration and biocontrol activity. Although the titratable acidity of pear fruits increased after treatment, R. mucilaginosa did not affect the total soluble solids or ascorbic acid content. This is the first study to report that the yeast R. mucilaginosa from Tibet Autonomous Region of China may have potential as an antagonist to control the postharvest decay of pear fruits. PMID:25845361

Evaluation of yeasts from Tibetan fermented products as agents for biocontrol of blue mold of Nashi pear fruits.

PubMed

Hu, Hao; Xu, Yang; Lu, Huang-ping; Xiao, Rui; Zheng, Xiao-dong; Yu, Ting

2015-04-01

A total of 20 strains of yeast isolated from Tibetan fermented products were screened for antagonism against blue mold of pear caused by Penicillium expansum. Six isolates that inhibited incidence of postharvest decay by 35% or more were selected for further screening. Among them, the most effective was Rhodotorula mucilaginosa. The results showed that washed cell suspensions of R. mucilaginosa yielded better antagonistic efficacy than unwashed cell-culture mixtures, cell-free culture filtrates, and autoclaved cell cultures. Biocontrol activity improved with increasing concentrations of incubated cells. The best concentration was 1×10(8) cells/ml, at which the incidence of decay was only 16.7% after 6 d of incubation. The germination of conidia of P. expansum in vitro was significantly inhibited by both washed cell-suspensions and unwashed cell-culture mixtures. Rapid colonization by yeast at different concentrations showed a relationship between yeast-cell concentration and biocontrol activity. Although the titratable acidity of pear fruits increased after treatment, R. mucilaginosa did not affect the total soluble solids or ascorbic acid content. This is the first study to report that the yeast R. mucilaginosa from Tibet Autonomous Region of China may have potential as an antagonist to control the postharvest decay of pear fruits.

Microbial cell disruption for improving lipid recovery using pressurized CO2 : Role of CO2 solubility in cell suspension, sugar broth, and spent media.

PubMed

Howlader, Md Shamim; French, William Todd; Shields-Menard, Sara A; Amirsadeghi, Marta; Green, Magan; Rai, Neeraj

2017-05-01

The study of in situ gas explosion to lyse the triglyceride-rich cells involves the solubilization of gas (e.g., carbon dioxide, CO 2 ) in lipid-rich cells under pressure followed by a rapid decompression, which allows the gas inside the cell to rapidly expand and rupture the cell from inside out. The aim of this study was to perform the cell disruption using pressurized CO 2 as well as to determine the solubility of CO 2 in Rhodotorula glutinis cell suspension, sugar broth media, and spent media. Cell disruption of R. glutinis was performed at two pressures of 2,000 and 3,500 kPa, respectively, at 295.2 K, and it was found from both scanning electron microscopy (SEM) and plate count that a substantial amount of R. glutinis was disrupted due to the pressurized CO 2 . We also found a considerable portion of lipid present in the aqueous phase after the disruption at P = 3,500 kPa compared to control (no pressure) and P = 2,000 kPa, which implied that more intracellular lipid was released due to the pressurized CO 2 . Solubility of CO 2 in R. glutinis cell suspension was found to be higher than the solubility of CO 2 in both sugar broth media and spent media. Experimental solubility was correlated using the extended Henry's law, which showed a good agreement with the experimental data. Enthalpy and entropy of dissolution of CO 2 were found to be -14.22 kJ mol -1 and 48.10 kJ mol -1  K -1 , 9.64 kJ mol -1 and 32.52 kJ mol -1  K -1 , and 7.50 kJ mol -1 and 25.22 kJ mol -1  K -1 in R. glutinis, spent media, and sugar broth media, respectively. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:737-748, 2017. © 2017 American Institute of Chemical Engineers.

High-titer production and strong antimicrobial activity of sophorolipids from Rhodotorula bogoriensis

USDA-ARS?s Scientific Manuscript database

Rhodotorula bogoriensis produces sophorolipids (SLs) that contain 13-hydroxydocosanoic acid (OH-C22) as the lipid moiety. A systematic study was conducted to further understand the fermentative production of SLs containing OH-C22 (C22-SL) by R. bogoriensis. Shake-flask studies showed that R. bogor...

Yeasts from skin colonization are able to cross the acellular dermal matrix.

PubMed

Jarros, Isabele Carrilho; Okuno, Érika; Costa, Maiara Ignacio; Veiga, Flávia Franco; de Souza Bonfim-Mendonça, Patricia; Negri, Melyssa Fernanda Norman; Svidzinski, Terezinha Inez Estivalet

2018-04-01

In recent decades, the prognosis for burn patients has improved considerably with the development of specialized care. The acellular dermal matrix (ADM) is a totally artificial acellular device that functions to control water loss, prevent penetration by bacteria and allow migration of endothelial cells and fibroblasts from patient tissues. However, little is known about its effectiveness against yeasts. The present study evaluated the capacity of colonization and migration of some human commensal yeasts. Three clinical isolates from skin scales, identified as Candida parapsilosis, Candida glabrata and Rhodotorula mucilaginosa, were used. Their ability to cross the ADM was evaluated. After three days, all isolates had crossed the ADM. C. parapsilosis showed the lowest growth, while R. mucilaginosa showed intermediate and C. glabrata the highest growth. In the plates incubated for seven days, the growth of C. parapsilosis and C. glabrata increased by 1 log over the third day. All isolates have the capacity to colonize and migrate through the matrix, increasing the potential risk to burn patients, who can develop severe and even fatal infections by invasive fungi. Copyright © 2018 Elsevier Ltd. All rights reserved.

Saccharomyces cerevisiae and non-Saccharomyces yeasts in grape varieties of the São Francisco Valley

PubMed Central

de Ponzzes-Gomes, Camila M.P.B.S.; de Mélo, Dângelly L.F.M.; Santana, Caroline A.; Pereira, Giuliano E.; Mendonça, Michelle O.C.; Gomes, Fátima C.O.; Oliveira, Evelyn S.; Barbosa, Antonio M.; Trindade, Rita C.; Rosa, Carlos A.

2014-01-01

The aims of this work was to characterise indigenous Saccharomyces cerevisiae strains in the naturally fermented juice of grape varieties Cabernet Sauvignon, Grenache, Tempranillo, Sauvignon Blanc and Verdejo used in the São Francisco River Valley, northeastern Brazil. In this study, 155 S. cerevisiae and 60 non-Saccharomyces yeasts were isolated and identified using physiological tests and sequencing of the D1/D2 domains of the large subunit of the rRNA gene. Among the non-Saccharomyces species, Rhodotorula mucilaginosa was the most common species, followed by Pichia kudriavzevii, Candida parapsilosis, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Kloeckera apis, P. manshurica, C. orthopsilosis and C. zemplinina. The population counts of these yeasts ranged among 1.0 to 19 × 105 cfu/mL. A total of 155 isolates of S. cerevisiae were compared by mitochondrial DNA restriction analysis, and five molecular mitochondrial DNA restriction profiles were detected. Indigenous strains of S. cerevisiae isolated from grapes of the São Francisco Valley can be further tested as potential starters for wine production. PMID:25242923

Saccharomyces cerevisiae and non-Saccharomyces yeasts in grape varieties of the São Francisco Valley.

PubMed

de Ponzzes-Gomes, Camila M P B S; de Mélo, Dângelly L F M; Santana, Caroline A; Pereira, Giuliano E; Mendonça, Michelle O C; Gomes, Fátima C O; Oliveira, Evelyn S; Barbosa, Antonio M; Trindade, Rita C; Rosa, Carlos A

2014-01-01

The aims of this work was to characterise indigenous Saccharomyces cerevisiae strains in the naturally fermented juice of grape varieties Cabernet Sauvignon, Grenache, Tempranillo, Sauvignon Blanc and Verdejo used in the São Francisco River Valley, northeastern Brazil. In this study, 155 S. cerevisiae and 60 non-Saccharomyces yeasts were isolated and identified using physiological tests and sequencing of the D1/D2 domains of the large subunit of the rRNA gene. Among the non-Saccharomyces species, Rhodotorula mucilaginosa was the most common species, followed by Pichia kudriavzevii, Candida parapsilosis, Meyerozyma guilliermondii, Wickerhamomyces anomalus, Kloeckera apis, P. manshurica, C. orthopsilosis and C. zemplinina. The population counts of these yeasts ranged among 1.0 to 19 × 10(5) cfu/mL. A total of 155 isolates of S. cerevisiae were compared by mitochondrial DNA restriction analysis, and five molecular mitochondrial DNA restriction profiles were detected. Indigenous strains of S. cerevisiae isolated from grapes of the São Francisco Valley can be further tested as potential starters for wine production.

Dead biomass of Amazon yeast: A new insight into bioremediation and recovery of silver by intracellular synthesis of nanoparticles.

PubMed

Salvadori, Marcia R; Ando, Rômulo A; Nascimento, Cláudio A Oller; Corrêa, Benedito

2017-09-19

This investigation was undertaken to describe a natural process for the removal of silver and the simultaneous recovery of Ag/Ag 2 O nanoparticles by dead biomass of the yeast Rhodotorula mucilaginosa. The removal of silver ions from aqueous solution and the synthesis of Ag/Ag 2 O nanoparticles were analyzed based on physicochemical factors and equilibrium concentration, combined with transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (FTIR). A successful process for the synthesis of Ag/Ag 2 O nanoparticles was obtained, following the Langmuir isotherm model, showing a high biosorption capacity of silver (49.0 mg g -1 ). The nanoparticles were spherical, had an average size of 11.0 nm, were synthesized intracellularly and capped by yeast proteins. This sustainable protocol is an attractive platform for the industrial-scale production of silver nanoparticles and of a silver nanobiosorbent.

Production, purification, and characterization of an extracellular acid protease from the marine Antarctic yeast Rhodotorula mucilaginosa L7.

PubMed

Lario, Luciana Daniela; Chaud, Luciana; Almeida, María das Graças; Converti, Attilio; Durães Sette, Lara; Pessoa, Adalberto

2015-11-01

The production, purification, and characterization of an extracellular protease released by Rhodotorula mucilaginosa L7 were evaluated in this study. This strain was isolated from an Antarctic marine alga and previously selected among others based on the capacity to produce the highest extracellular proteolytic activity in preliminary tests. R. mucilaginosa L7 was grown in Saboraud-dextrose medium at 25 °C, and the cell growth, pH of the medium, extracellular protease production and the glucose and protein consumption were determined as a function of time. The protease was then purified, and the effects of pH, temperature, and salt concentration on the catalytic activity and enzyme stability were determined. Enzyme production started at the beginning of the exponential phase of growth and reached a maximum after 48 h, which was accompanied by a decrease in the pH as well as reductions of the protein and glucose concentrations in the medium. The purified protease presented optimal catalytic activity at pH 5.0 and 50 °C. Finally, the enzyme was stable in the presence of high concentrations of NaCl. These characteristics are of interest for future studies and may lead to potential biotechnological applications that require enzyme activity and stability under acidic conditions and/or high salt concentrations. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Are the Conventional Commercial Yeast Identification Methods Still Helpful in the Era of New Clinical Microbiology Diagnostics? A Meta-Analysis of Their Accuracy

PubMed Central

Efremov, Ljupcho; Leoncini, Emanuele; Amore, Rosarita; Posteraro, Patrizia; Ricciardi, Walter

2015-01-01

Accurate identification of pathogenic species is important for early appropriate patient management, but growing diversity of infectious species/strains makes the identification of clinical yeasts increasingly difficult. Among conventional methods that are commercially available, the API ID32C, AuxaColor, and Vitek 2 systems are currently the most used systems in routine clinical microbiology. We performed a systematic review and meta-analysis to estimate and to compare the accuracy of the three systems, in order to assess whether they are still of value for the species-level identification of medically relevant yeasts. After adopting rigorous selection criteria, we included 26 published studies involving Candida and non-Candida yeasts that were tested with the API ID32C (674 isolates), AuxaColor (1,740 isolates), and Vitek 2 (2,853 isolates) systems. The random-effects pooled identification ratios at the species level were 0.89 (95% confidence interval [CI], 0.80 to 0.95) for the API ID32C system, 0.89 (95% CI, 0.83 to 0.93) for the AuxaColor system, and 0.93 (95% CI, 0.89 to 0.96) for the Vitek 2 system (P for heterogeneity, 0.255). Overall, the accuracy of studies using phenotypic analysis-based comparison methods was comparable to that of studies using molecular analysis-based comparison methods. Subanalysis of studies conducted on Candida yeasts showed that the Vitek 2 system was significantly more accurate (pooled ratio, 0.94 [95% CI, 0.85 to 0.99]) than the API ID32C system (pooled ratio, 0.84 [95% CI, 0.61 to 0.99]) and the AuxaColor system (pooled ratio, 0.76 [95% CI, 0.67 to 0.84]) with respect to uncommon species (P for heterogeneity, <0.05). Subanalysis of studies conducted on non-Candida yeasts (i.e., Cryptococcus, Rhodotorula, Saccharomyces, and Trichosporon) revealed pooled identification accuracies of ≥98% for the Vitek 2, API ID32C (excluding Cryptococcus), and AuxaColor (only Rhodotorula) systems, with significant low or null levels of

Are the Conventional Commercial Yeast Identification Methods Still Helpful in the Era of New Clinical Microbiology Diagnostics? A Meta-Analysis of Their Accuracy.

PubMed

Posteraro, Brunella; Efremov, Ljupcho; Leoncini, Emanuele; Amore, Rosarita; Posteraro, Patrizia; Ricciardi, Walter; Sanguinetti, Maurizio

2015-08-01

Accurate identification of pathogenic species is important for early appropriate patient management, but growing diversity of infectious species/strains makes the identification of clinical yeasts increasingly difficult. Among conventional methods that are commercially available, the API ID32C, AuxaColor, and Vitek 2 systems are currently the most used systems in routine clinical microbiology. We performed a systematic review and meta-analysis to estimate and to compare the accuracy of the three systems, in order to assess whether they are still of value for the species-level identification of medically relevant yeasts. After adopting rigorous selection criteria, we included 26 published studies involving Candida and non-Candida yeasts that were tested with the API ID32C (674 isolates), AuxaColor (1,740 isolates), and Vitek 2 (2,853 isolates) systems. The random-effects pooled identification ratios at the species level were 0.89 (95% confidence interval [CI], 0.80 to 0.95) for the API ID32C system, 0.89 (95% CI, 0.83 to 0.93) for the AuxaColor system, and 0.93 (95% CI, 0.89 to 0.96) for the Vitek 2 system (P for heterogeneity, 0.255). Overall, the accuracy of studies using phenotypic analysis-based comparison methods was comparable to that of studies using molecular analysis-based comparison methods. Subanalysis of studies conducted on Candida yeasts showed that the Vitek 2 system was significantly more accurate (pooled ratio, 0.94 [95% CI, 0.85 to 0.99]) than the API ID32C system (pooled ratio, 0.84 [95% CI, 0.61 to 0.99]) and the AuxaColor system (pooled ratio, 0.76 [95% CI, 0.67 to 0.84]) with respect to uncommon species (P for heterogeneity, <0.05). Subanalysis of studies conducted on non-Candida yeasts (i.e., Cryptococcus, Rhodotorula, Saccharomyces, and Trichosporon) revealed pooled identification accuracies of ≥98% for the Vitek 2, API ID32C (excluding Cryptococcus), and AuxaColor (only Rhodotorula) systems, with significant low or null levels of

A comparative study on the potential of epiphytic yeasts isolated from tropical fruits to produce flavoring compounds.

PubMed

Grondin, Eric; Shum Cheong Sing, Alain; Caro, Yanis; Raherimandimby, Marson; Randrianierenana, Ando Lalaniaina; James, Steve; Nueno-Palop, Carmen; François, Jean Marie; Petit, Thomas

2015-06-16

In recent years, there has been an increasing interest in identifying and characterizing the yeast flora associated with diverse types of habitat because of the many potential desirable technological properties of these microorganisms, especially in food applications. In this study, a total of 101 yeast strains were isolated from the skins of tropical fruits collected in several locations in the South West Indian Ocean. Sequence analysis of the D1/D2 domains of the large subunit (LSU) ribosomal RNA gene identified 26 different species. Among them, two species isolated from the skins of Cape gooseberry and cocoa beans appeared to represent putative new yeast species, as their LSU D1/D2 sequence was only 97.1% and 97.4% identical to that of the yeasts Rhodotorula mucilaginosa and Candida pararugosa, respectively. A total of 52 Volatile Organic Compounds (VOCs) were detected by Head Space Solid Phase Micro Extraction coupled to Gas Chromatography and Mass Spectroscopy (HS-SPME-GC/MS) from the 26 yeast species cultivated on a glucose rich medium. Among these VOCs, 6 uncommon compounds were identified, namely ethyl but-2-enoate, ethyl 2-methylbut-2-enoate (ethyl tiglate), ethyl 3-methylbut-2-enoate, 2-methylpropyl 2-methylbut-2-enoate, butyl 2-methylbut-2-enoate and 3-methylbutyl 2-methylbut-2-enoate, making them possible yeast species-specific markers. In addition, statistical methods such as Principal Component Analysis allowed to associate each yeast species with a specific flavor profile. Among them, Saprochaete suaveolens (syn: Geotrichum fragrans) turned to be the best producer of flavor compounds, with a total of 32 out of the 52 identified VOCs in its flavor profile. Copyright © 2015 Elsevier B.V. All rights reserved.

Complete mitochondrial genome of the aluminum-tolerant fungus Rhodotorula taiwanensis RS1 and comparative analysis of Basidiomycota mitochondrial genomes

PubMed Central

Zhao, Xue Qiang; Aizawa, Tomoko; Schneider, Jessica; Wang, Chao; Shen, Ren Fang; Sunairi, Michio

2013-01-01

The complete mitochondrial genome of Rhodotorula taiwanensis RS1, an aluminum-tolerant Basidiomycota fungus, was determined and compared with the known mitochondrial genomes of 12 Basidiomycota species. The mitochondrial genome of R. taiwanensis RS1 is a circular DNA molecule of 40,392 bp and encodes the typical 15 mitochondrial proteins, 23 tRNAs, and small and large rRNAs as well as 10 intronic open reading frames. These genes are apparently transcribed in two directions and do not show syntenies in gene order with other investigated Basidiomycota species. The average G+C content (41%) of the mitochondrial genome of R. taiwanensis RS1 is the highest among the Basidiomycota species. Two introns were detected in the sequence of the atp9 gene of R. taiwanensis RS1, but not in that of other Basidiomycota species. Rhodotorula taiwanensis is the first species of the genus Rhodotorula whose full mitochondrial genome has been sequenced; and the data presented here supply valuable information for understanding the evolution of fungal mitochondrial genomes and researching the mechanism of aluminum tolerance in microorganisms. PMID:23427135

Recovery of Fuel-Precursor Lipids from Oleaginous Yeast

DOE PAGES

Kruger, Jacob S.; Cleveland, Nicholas S.; Yeap, Rou Yi; ...

2018-01-24

Bio-derived lipids offer a potentially promising intermediate to displace petroleum-derived diesel. One of the key challenges for the production of lipids via microbial cell mass is that these products are stored intracellularly and must be extracted and recovered efficiently and economically. Thus, improved methods of cell lysis and lipid extraction are needed. In this study, we examine lipid extraction from wet oleaginous yeast in combination with seven different cell lysis approaches encompassing both physical and chemical techniques (high-pressure homogenization, microwave and conventional thermal treatments, bead beating, acid, base, and enzymatic treatments) to facilitate lipid extraction from a model oleaginous yeastmore » strain, Lipomyces starkeyi. Of the seven techniques investigated, acid treatment led to the highest lipid recovery yields. Further exploration of acid treatment and integration with an economic model revealed that treatment at 170 degrees C for 60 min at 1 wt% H 2SO 4 and 8 wt% yeast solids represents a viable option for both lipid recovery yield and process economics, enabling experimental lipid recovery yields of 88.5-93.0% to be achieved at a corresponding estimated minimum fuel selling price (MFSP) of $5.13-$5.61/gallon of gasoline equivalent (GGE). The same acid treatment conditions applied to two other strains of oleaginous yeast (Cutaneotrichosporon curvatus and Rhodotorula toruloides) resulted in similar lipid recovery yields. In pretreatment experiments scaled up to 300 mL, slightly lower temperatures or shorter pretreatment times, along with higher yeast solids loading, resulted in higher lipid yields than the conditions identified from the small-scale runs. Two replicate runs carried out at 170 degrees C for 30 min using 1 wt% H2SO4 and 19 wt% yeast solids achieved an average lipid recovery of 96.1% at a corresponding estimated MFSP of $4.89/GGE. In all cases, the lipids are primarily triglycerides and free fatty acids

Recovery of Fuel-Precursor Lipids from Oleaginous Yeast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruger, Jacob S.; Cleveland, Nicholas S.; Yeap, Rou Yi

Bio-derived lipids offer a potentially promising intermediate to displace petroleum-derived diesel. One of the key challenges for the production of lipids via microbial cell mass is that these products are stored intracellularly and must be extracted and recovered efficiently and economically. Thus, improved methods of cell lysis and lipid extraction are needed. In this study, we examine lipid extraction from wet oleaginous yeast in combination with seven different cell lysis approaches encompassing both physical and chemical techniques (high-pressure homogenization, microwave and conventional thermal treatments, bead beating, acid, base, and enzymatic treatments) to facilitate lipid extraction from a model oleaginous yeastmore » strain, Lipomyces starkeyi. Of the seven techniques investigated, acid treatment led to the highest lipid recovery yields. Further exploration of acid treatment and integration with an economic model revealed that treatment at 170 degrees C for 60 min at 1 wt% H 2SO 4 and 8 wt% yeast solids represents a viable option for both lipid recovery yield and process economics, enabling experimental lipid recovery yields of 88.5-93.0% to be achieved at a corresponding estimated minimum fuel selling price (MFSP) of $5.13-$5.61/gallon of gasoline equivalent (GGE). The same acid treatment conditions applied to two other strains of oleaginous yeast (Cutaneotrichosporon curvatus and Rhodotorula toruloides) resulted in similar lipid recovery yields. In pretreatment experiments scaled up to 300 mL, slightly lower temperatures or shorter pretreatment times, along with higher yeast solids loading, resulted in higher lipid yields than the conditions identified from the small-scale runs. Two replicate runs carried out at 170 degrees C for 30 min using 1 wt% H2SO4 and 19 wt% yeast solids achieved an average lipid recovery of 96.1% at a corresponding estimated MFSP of $4.89/GGE. In all cases, the lipids are primarily triglycerides and free fatty acids

Process Analysis of Variables for Standardization of Antifungal Susceptibility Testing of Nonfermentative Yeasts ▿

PubMed Central

Zaragoza, Oscar; Mesa-Arango, Ana C.; Gómez-López, Alicia; Bernal-Martínez, Leticia; Rodríguez-Tudela, Juan Luis; Cuenca-Estrella, Manuel

2011-01-01

Nonfermentative yeasts, such as Cryptococcus spp., have emerged as fungal pathogens during the last few years. However, standard methods to measure their antifungal susceptibility (antifungal susceptibility testing [AST]) are not completely reliable due to the impaired growth of these yeasts in standard media. In this work, we have compared the growth kinetics and the antifungal susceptibilities of representative species of nonfermentative yeasts such as Cryptococcus neoformans, Cryptococcus gattii, Cryptococcus albidus, Rhodotorula spp., Yarrowia lipolytica, Geotrichum spp., and Trichosporon spp. The effect of the growth medium (RPMI medium versus yeast nitrogen base [YNB]), glucose concentration (0.2% versus 2%), nitrogen source (ammonium sulfate), temperature (30°C versus 35°C), shaking, and inoculum size (103, 104, and 105 cells) were analyzed. The growth rate, lag phase, and maximum optical density were obtained from each growth experiment, and after multivariate analysis, YNB-based media demonstrated a significant improvement in the growth of yeasts. Shaking, an inoculum size of 105 CFU/ml, and incubation at 30°C also improved the growth kinetics of organisms. Supplementation with ammonium sulfate and with 2% glucose did not have any effect on growth. We also tested the antifungal susceptibilities of all the isolates by the reference methods of the CLSI and EUCAST, the EUCAST method with shaking, YNB under static conditions, and YNB with shaking. MIC values obtained under different conditions showed high percentages of agreement and significant correlation coefficient values between them. MIC value determinations according to CLSI and EUCAST standards were rather complicated, since more than half of isolates tested showed a limited growth index, hampering endpoint determinations. We conclude that AST conditions including YNB as an assay medium, agitation of the plates, reading after 48 h of incubation, an inoculum size of 105 CFU/ml, and incubation at 30�

Hydroxy-Al and cell-surface negativity are responsible for the enhanced sensitivity of Rhodotorula taiwanensis to aluminum by increased medium pH.

PubMed

Zhao, Xue Qiang; Bao, Xue Min; Wang, Chao; Xiao, Zuo Yi; Hu, Zhen Min; Zheng, Chun Li; Shen, Ren Fang

2017-10-01

Aluminum (Al) is ubiquitous and toxic to microbes. High Al 3+ concentration and low pH are two key factors responsible for Al toxicity, but our present results contradict this idea. Here, an Al-tolerant yeast strain Rhodotorula taiwanensis RS1 was incubated in glucose media containing Al with a continuous pH gradient from pH 3.1-4.2. The cells became more sensitive to Al and accumulated more Al when pH increased. Calculations using an electrostatic model Speciation Gouy Chapman Stern indicated that, the increased Al sensitivity of cells was associated with AlOH 2+ and Al(OH) 2 + rather than Al 3+ . The alcian blue (a positively charged dye) adsorption and zeta potential determination of cell surface indicated that, higher pH than 3.1 increased the negative charge and Al adsorption at the cell surface. Taken together, the enhanced sensitivity of R. taiwanensis RS1 to Al from pH 3.1-4.2 was associated with increased hydroxy-Al and cell-surface negativity.

Study of the counts, species and characteristics of the yeast population during the manufacture of dry-cured "lacón". Effect of salt level.

PubMed

Purriños, Laura; García Fontán, María C; Carballo, Javier; Lorenzo, José M

2013-05-01

The aim of this work was to study the yeast population during the manufacture of dry-cured "lacón" (a Spanish traditional meat product) and the effect of the salting time. For this study, six batches of "lacón" were manufactured with three different salting times (LS (3 days of salting), MS (4 days of salting) and HS (5 days of salting)). Yeast counts increased significantly (P < 0.001) during the whole process from 2.60 to 6.37 log cfu/g. An increased length of salting time did not affect yeast counts throughout the manufacture of dry-cured "lacón", although the highest yeast counts were obtained from LS batches. A total of 226 isolates were obtained from dry-cured "lacón" during drying-ripening stage, of which 151 were yeasts and were identified at the species level using molecular techniques. The total of 151 identified yeasts belonged to 4 different genera: Debaryomyces, Candida, Cryptococcus and Rhodotorula. Debaryomyces hansenii was the most abundant species isolated throughout the whole process as much in the interior as in the exterior of the pieces of three salt levels of "lacón" studied, while Candida zeylanoides was only isolated from the interior of MS and HS batches and from the exterior of LS and HS groups, but at lesser proportion than D. hansenii. Copyright © 2012. Published by Elsevier Ltd.

Complete mitochondrial genome of the aluminum-tolerant fungus Rhodotorula taiwanensis RS1 and comparative analysis of Basidiomycota mitochondrial genomes.

PubMed

Zhao, Xue Qiang; Aizawa, Tomoko; Schneider, Jessica; Wang, Chao; Shen, Ren Fang; Sunairi, Michio

2013-04-01

The complete mitochondrial genome of Rhodotorula taiwanensis RS1, an aluminum-tolerant Basidiomycota fungus, was determined and compared with the known mitochondrial genomes of 12 Basidiomycota species. The mitochondrial genome of R. taiwanensis RS1 is a circular DNA molecule of 40,392 bp and encodes the typical 15 mitochondrial proteins, 23 tRNAs, and small and large rRNAs as well as 10 intronic open reading frames. These genes are apparently transcribed in two directions and do not show syntenies in gene order with other investigated Basidiomycota species. The average G+C content (41%) of the mitochondrial genome of R. taiwanensis RS1 is the highest among the Basidiomycota species. Two introns were detected in the sequence of the atp9 gene of R. taiwanensis RS1, but not in that of other Basidiomycota species. Rhodotorula taiwanensis is the first species of the genus Rhodotorula whose full mitochondrial genome has been sequenced; and the data presented here supply valuable information for understanding the evolution of fungal mitochondrial genomes and researching the mechanism of aluminum tolerance in microorganisms. © 2013 The Authors. Published by Blackwell Publishing Ltd.

Functional genomics of lipid metabolism in the oleaginous yeast Rhodosporidium toruloides

PubMed Central

Geiselman, Gina M; Ito, Masakazu; Mondo, Stephen J; Reilly, Morgann C; Cheng, Ya-Fang; Bauer, Stefan; Grigoriev, Igor V; Gladden, John M; Simmons, Blake A; Brem, Rachel B

2018-01-01

The basidiomycete yeast Rhodosporidium toruloides (also known as Rhodotorula toruloides) accumulates high concentrations of lipids and carotenoids from diverse carbon sources. It has great potential as a model for the cellular biology of lipid droplets and for sustainable chemical production. We developed a method for high-throughput genetics (RB-TDNAseq), using sequence-barcoded Agrobacterium tumefaciens T-DNA insertions. We identified 1,337 putative essential genes with low T-DNA insertion rates. We functionally profiled genes required for fatty acid catabolism and lipid accumulation, validating results with 35 targeted deletion strains. We identified a high-confidence set of 150 genes affecting lipid accumulation, including genes with predicted function in signaling cascades, gene expression, protein modification and vesicular trafficking, autophagy, amino acid synthesis and tRNA modification, and genes of unknown function. These results greatly advance our understanding of lipid metabolism in this oleaginous species and demonstrate a general approach for barcoded mutagenesis that should enable functional genomics in diverse fungi. PMID:29521624

Functional genomics of lipid metabolism in the oleaginous yeast Rhodosporidium toruloides

DOE PAGES

Coradetti, Samuel T.; Pinel, Dominic; Geiselman, Gina M.; ...

2018-03-09

The basidiomycete yeast Rhodosporidium toruloides (also known as Rhodotorula toruloides) accumulates high concentrations of lipids and carotenoids from diverse carbon sources. It has great potential as a model for the cellular biology of lipid droplets and for sustainable chemical production. We developed a method for high-throughput genetics (RB-TDNAseq), using sequence-barcoded Agrobacterium tumefaciens T-DNA insertions. We identified 1,337 putative essential genes with low T-DNA insertion rates. We functionally profiled genes required for fatty acid catabolism and lipid accumulation, validating results with 35 targeted deletion strains. We identified a high-confidence set of 150 genes affecting lipid accumulation, including genes with predicted functionmore » in signaling cascades, gene expression, protein modification and vesicular trafficking, autophagy, amino acid synthesis and tRNA modification, and genes of unknown function. Lastly, these results greatly advance our understanding of lipid metabolism in this oleaginous species and demonstrate a general approach for barcoded mutagenesis that should enable functional genomics in diverse fungi.« less

Functional genomics of lipid metabolism in the oleaginous yeast Rhodosporidium toruloides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coradetti, Samuel T.; Pinel, Dominic; Geiselman, Gina M.

The basidiomycete yeast Rhodosporidium toruloides (also known as Rhodotorula toruloides) accumulates high concentrations of lipids and carotenoids from diverse carbon sources. It has great potential as a model for the cellular biology of lipid droplets and for sustainable chemical production. We developed a method for high-throughput genetics (RB-TDNAseq), using sequence-barcoded Agrobacterium tumefaciens T-DNA insertions. We identified 1,337 putative essential genes with low T-DNA insertion rates. We functionally profiled genes required for fatty acid catabolism and lipid accumulation, validating results with 35 targeted deletion strains. We identified a high-confidence set of 150 genes affecting lipid accumulation, including genes with predicted functionmore » in signaling cascades, gene expression, protein modification and vesicular trafficking, autophagy, amino acid synthesis and tRNA modification, and genes of unknown function. Lastly, these results greatly advance our understanding of lipid metabolism in this oleaginous species and demonstrate a general approach for barcoded mutagenesis that should enable functional genomics in diverse fungi.« less

Highly cold-active pectinases under wine-like conditions from non-Saccharomyces yeasts for enzymatic production during winemaking.

PubMed

Merín, M G; Morata de Ambrosini, V I

2015-05-01

The influence of oenological factors on cold-active pectinases from 15 preselected indigenous yeasts belonging to Aureobasidium pullulans, Filobasidium capsuligenum, Rhodotorula dairenensis, Cryptococcus saitoi and Saccharomyces cerevisiae was investigated. Pectinolytic enzymes were constitutive or partially constitutive; and high glucose concentration (200 g l(-1) ) did not affect or increased pectinase production at 12°C and pH 3·5 (up to 113·9 U mg(-1) ) only in A. pullulans strains. SO2 (120 mg l(-1) ) slightly affected the growth of A. pullulans strains but did not affect pectinase production levels. Ethanol (15%) barely affected pectinase activity of A. pullulans strains but diminished relative activity to 12-79% of basidiomycetous yeasts. Moreover, non-Saccharomyces strains showed promising properties of oenological interest. This study demonstrates that cold-active pectinases from some A. pullulans strains were able to remain active at glucose, ethanol and SO2 concentrations usually found in vinification, and suggests their potential use as processing aids for low-temperature winemaking. Nowadays, there is increasing interest in low-temperature winemaking. Nevertheless, commercial oenological pectinases, produced by fungi, are rarely active at low temperatures. Cold-active pectinases that are stable under vinification conditions are needed. This study indicated that cold-active and acid-tolerant pectinases from non-Saccharomcyes yeasts were able to remain active at glucose, ethanol and SO2 concentrations usually found in winemaking. Furthermore, not only are these yeasts a source of cold-active pectinases, but the yeasts themselves are also potential adjunct cultures for oenology to produce these enzymes during cold-winemaking. © 2015 The Society for Applied Microbiology.

Purification and characterization of a novel cold-adapted phytase from Rhodotorula mucilaginosa strain JMUY14 isolated from Antarctic.

PubMed

Yu, Peng; Wang, Xue-Ting; Liu, Jing-Wen

2015-08-01

A yeast producing a cold-adapted phytase was isolated from Antarctic deep-sea sediment and identified as a Rhodotorula mucilaginosa strain JMUY14 of basidiomycetous yeasts. It was cultured in fermentation optimized by a response surface methodology based on the Box-Behnken design. The maximum activity of phytase reached 205.447 U ml(-1), which was close to the predicted value of 201.948 U ml(-1) and approximately 3.4 times higher than its initial activity. The extracellular phytase was purified by 15.2-fold to homogeneity with a specific activity of 31,635 U mg(-1) by (NH4 )2 SO4 precipitation, and a combination of DEAE Sepharose Fast Flow, SP Sepharose Fast Flow, and Sephadex G-100. The molecular weight of the purified enzyme was estimated to be 63 kDa and its pI was 4.33. Its optimal temperature and pH were 50 °C and 5.0, respectively. Its activity was 85% at 37 °C, and showed good stability at pH 3.0 ∼ 7.0. When compared with mesophilic counterparts, the phytase not only exhibited a higher activity during 20 ∼ 30 °C but also had a low Km (247 µM) and high kcat (1394 s(-1)). The phytase activity was slightly stimulated in the presence of Mg(2+), Fe(2+), Fe(3+), K(+), Na(+), Ca(2+), EDTA, and EGTA and moderately inhibited by Cu(2+), Zn(2+), Mn(2+), Ag(+), PMSF, SDS, and phenylgloxal hydrate. It was resistant to both pepsin and trypsin. Since the phytase produced by the R. mucilaginosa JMUY14 showed a high specific activity, good pH stability, strong protease resistance, and high activity at low temperature, it has great potential for feed applications, especially in aquaculture. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microbial Competition of Rhodotorula mucilaginosa UANL-001L and E. coli increase biosynthesis of Non-Toxic Exopolysaccharide with Applications as a Wide-Spectrum Antimicrobial.

PubMed

Vazquez-Rodriguez, Augusto; Vasto-Anzaldo, Ximena G; Barboza Perez, Daniel; Vázquez-Garza, Eduardo; Chapoy-Villanueva, Héctor; García-Rivas, Gerardo; Garza-Cervantes, Javier A; Gómez-Lugo, Jéssica J; Gomez-Loredo, Alma Elizabeth; Garza Gonzalez, Maria Teresa; Zarate, Xristo; Morones-Ramirez, Jose Ruben

2018-01-15

Bacterial species are able to colonize and establish communities in biotic and abiotic surfaces. Moreover, within the past five decades, incidence of bacterial strains resistant to currently used antibiotics has increased dramatically. This has led to diverse health issues and economical losses for different industries. Therefore, there is a latent need to develop new and more efficient antimicrobials. This work reports an increased production of an exopolysaccharide in a native yeast strain isolated from the Mexican Northeast, Rhodotorula mucilaginosa UANL-001L, when co-cultured with E. coli. The exopolysaccharide produced is chemically and physically characterized and its applications as an antimicrobial and antibiofilm are explored. The exopolysaccharide is capable of inhibiting planktonic growth and biofilm formation in Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. Additionally, the exopolysaccharide studied here does not exhibit cytotoxic effects when assessed both, in vitro against an H9c2 mammalian cell line, and in vivo in a murine toxicity model. Taken together, the properties of this exopolysaccharide indicate that it has potential applications to inhibit bacterial colonization in medical and industrial settlings.

Meningitis Caused by Rhodotorula mucilaginosa in HIV-Infected Patient: A Case Report and Review of the Literature.

PubMed

Mohd Nor, Fadzilah; Tan, Lian Huat; Na, Shi Ling; Ng, Kee Peng

2015-08-01

Rhodotorula species are increasingly being identified as a cause of fungal infection in the central nervous system, especially in patients with compromised immunity. The diagnosis could easily be missed due to low index of suspicion, as cryptococcus meningitis and cerebral toxoplasmosis are more common amongst immunocompromised hosts. To date, there are six cases of Rhodotorula-related meningitis reported, and three are associated with human immunodeficiency virus infection. In this report, a case of a Malaysian male with underlying human immunodeficiency virus infection who developed Rhodotorula mucilaginosa meningitis is presented. High-grade fever and severe headaches were the complaints presented in three previous case reports. India ink and nigrosin stainings were performed in the two previous reports and both revealed positive results. R. mucilaginosa were isolated from the culture of the patient's cerebrospinal fluid in all three previous reports. Predominant lymphocyte infiltration in the cerebrospinal fluid examination was documented in two reports. CD4 counts were above 100/µl in two previously published reports, while another report documented CD4 count as 56/µl. Amphotericin B and itraconazole are identified to be the first line of antifungal used and as the maintenance therapy, respectively. The possibility of relapse cannot be excluded as it was reported in the first report. It was also revealed that the current case has almost similar clinical presentation and therapeutic outcome as compared to the published reports, but some differences in diagnostic details were to be highlighted.

Ergothioneine production using Methylobacterium species, yeast, and fungi.

PubMed

Fujitani, Yoshiko; Alamgir, Kabir Md; Tani, Akio

2018-06-14

Ergothioneine (EGT) is a sulfur-containing, anti-oxidative amino acid derived from histidine. EGT is synthesized in bacteria and fungi but not in animals and plants, and is now recognized as important for human health. Its cost-effective fermentative production has not been elucidated due to the lack of information for productive microorganisms. In this study, we doubled the gene copy for EGT synthesis and deleted the histidine ammonia-lyase gene in a potent EGT-producing methylotrophic bacterium Methylobacterium aquaticum strain 22A, and optimized its culture conditions, resulting in increased EGT production of 7.0 mg EGT/g dry cell weight and 100 μg EGT/5 mL/7 days. In addition, through screening we found EGT-producing eukaryotic strains of Aureobasidium pullulans and Rhodotorula mucilaginosa, which can produce 1.0 and 3.2 mg EGT/g dry cell weight, 70 and 120 μg EGT/5 mL/7 days, respectively. This study proposes practical uses of potent EGT-producing recombinant Methylobacterium species and non-recombinant yeast and fungal strains. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Initial reactions involved in the dissimilation of mandelate by Rhodotorula graminis.

PubMed Central

Durham, D R

1984-01-01

Rhodotorula graminis utilized DL-mandelate, L(+)-mandelate, and D(-)-mandelate as sole sources of carbon and energy. Growth on these aromatic substrates resulted in the induction of an NAD-dependent D(-)-mandelate dehydrogenase and a dye-linked L(+)-mandelate dehydrogenase, each catalyzing the stereospecific conversion of its respective enantiomer of mandelate to benzoylformate. Benzoylformate was oxidized to benzaldehyde, which was dehydrogenated to benzoate by an NAD-dependent benzaldehyde dehydrogenase. Benzoate was further metabolized through p-hydroxybenzoate and the protocatechuate branch of the beta-ketoadipate pathway. PMID:6389497

Ecotoxicity and biodegradability of antielectrostatic dicephalic cationic surfactants.

PubMed

Piętka-Ottlik, Magdalena; Frąckowiak, Renata; Maliszewska, Irena; Kołwzan, Barbara; Wilk, Kazimiera A

2012-11-01

Four series of dicephalic cationic surfactants, considered as new antielectrostatic agents have been investigated in order to establish their toxicity and biodegradability. Among them N,N-bis[3,3'-(dimethylamine)propyl]alkylamides, N,N-bis[3,3'-(dimethylamine)propyl]alkylamide dihydrochlorides, N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dibromides and N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dimethylsulphates with different hydrophobic chain length (n-C(9)H(19) to n-C(15)H(31)) and type of counterion (chloride, bromide and methylsulfate) have been studied. The inhibitory effect against microorganisms has been examined using model gram-positive and gram-negative bacteria, and yeasts. None of the tested surfactants have shown antimicrobial activity against gram-negative bacteria (Escherichia coli, Pseudomonas putida) and yeasts (Saccharomyces cerevisiae, Rhodotorula glutinis) at a concentration below 1000 μg mL(-1), however some of them were moderately active against gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis). The Microtox® test was successfully applied to measure EC(50) values of the studied dicephalic cationic surfactants. Their toxicity to Vibrio fischeri depended upon the alkanoyl chain length with the EC(50) values in a range of 2.6-980 mg L(-1). N,N-bis[3,3'-(dimethylamine)propyl]alkylamide dihydrochlorides 2a-b and N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dibromides 3a-b comprising n-decanoyl and n-dodecanoyl hydrophobic tails appeared to be the least toxic. Furthermore, the biodegradability under aerobic conditions of 2a-b, 3a-b was evaluated using OECD Method 301F. According to the obtained results 2a, 3a-3b can be considered as almost readily biodegradable and they are not expected to be persistent in the environment. Additionally, partial biodegradation was observed for 2b, indicating its possible biodegradation in wastewater treatment systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sustainable conversion of coffee and other crop wastes to biofuels and bioproducts using coupled biochemical and thermochemical processes in a multi-stage biorefinery concept.

PubMed

Hughes, Stephen R; López-Núñez, Juan Carlos; Jones, Marjorie A; Moser, Bryan R; Cox, Elby J; Lindquist, Mitch; Galindo-Leva, Luz Angela; Riaño-Herrera, Néstor M; Rodriguez-Valencia, Nelson; Gast, Fernando; Cedeño, David L; Tasaki, Ken; Brown, Robert C; Darzins, Al; Brunner, Lane

2014-10-01

The environmental impact of agricultural waste from the processing of food and feed crops is an increasing concern worldwide. Concerted efforts are underway to develop sustainable practices for the disposal of residues from the processing of such crops as coffee, sugarcane, or corn. Coffee is crucial to the economies of many countries because its cultivation, processing, trading, and marketing provide employment for millions of people. In coffee-producing countries, improved technology for treatment of the significant amounts of coffee waste is critical to prevent ecological damage. This mini-review discusses a multi-stage biorefinery concept with the potential to convert waste produced at crop processing operations, such as coffee pulping stations, to valuable biofuels and bioproducts using biochemical and thermochemical conversion technologies. The initial bioconversion stage uses a mutant Kluyveromyces marxianus yeast strain to produce bioethanol from sugars. The resulting sugar-depleted solids (mostly protein) can be used in a second stage by the oleaginous yeast Yarrowia lipolytica to produce bio-based ammonia for fertilizer and are further degraded by Y. lipolytica proteases to peptides and free amino acids for animal feed. The lignocellulosic fraction can be ground and treated to release sugars for fermentation in a third stage by a recombinant cellulosic Saccharomyces cerevisiae, which can also be engineered to express valuable peptide products. The residual protein and lignin solids can be jet cooked and passed to a fourth-stage fermenter where Rhodotorula glutinis converts methane into isoprenoid intermediates. The residues can be combined and transferred into pyrocracking and hydroformylation reactions to convert ammonia, protein, isoprenes, lignins, and oils into renewable gas. Any remaining waste can be thermoconverted to biochar as a humus soil enhancer. The integration of multiple technologies for treatment of coffee waste has the potential to

Unravel lipid accumulation mechanism in oleaginous yeast through single cell systems biology study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Xiaoliang; Ding, Shiyou

Searching for alternative and clean energy is one of the most important tasks today. Our research aimed at finding the best living condition for certain types of oleaginous yeasts for efficient lipid production. We found that R. glutinis yeast cells has great variability in lipid production among cells while Y. lipolytica cells has similar oil production ability. We found some individual cells shows much higher level of oil production. In order to further study these cases, we employed a label-free chemical sensitive microscopy method call stimulated Raman scattering (SRS). With SRS, we could measure the lipid content in each cell.more » We combined SRS microscopy with microfluidic device so that we can isolate cells with high fat content. We also developed SRS imaging technique that has higher imaging speed, which is highly desirable for high throughput cell screening and sorting. Since these cells has similar genome, it must be the transcriptome caused their difference in oil production. We developed a single cell transcriptome sequencing method to study which genes are responsible for elevated oil production. These methods that are developed for this project can easily be applied for many other areas of research. For example, the single transcriptome can be used to study the transcriptomes of other cell types. The high-speed SRS microscopy techniques can be used to speed up chemical imaging for lablefree histology or imaging distribution of chemicals in tissues of live mice or in humans. The developed microfluidic platform can be used to sort other type of cells, e.g., white blood cells for diagnosis of cancer or other blood diseases.« less

Identification of Medically Important Yeasts Using PCR-Based Detection of DNA Sequence Polymorphisms in the Internal Transcribed Spacer 2 Region of the rRNA Genes

PubMed Central

Chen, Y. C.; Eisner, J. D.; Kattar, M. M.; Rassoulian-Barrett, S. L.; LaFe, K.; Yarfitz, S. L.; Limaye, A. P.; Cookson, B. T.

2000-01-01

Identification of medically relevant yeasts can be time-consuming and inaccurate with current methods. We evaluated PCR-based detection of sequence polymorphisms in the internal transcribed spacer 2 (ITS2) region of the rRNA genes as a means of fungal identification. Clinical isolates (401), reference strains (6), and type strains (27), representing 34 species of yeasts were examined. The length of PCR-amplified ITS2 region DNA was determined with single-base precision in less than 30 min by using automated capillary electrophoresis. Unique, species-specific PCR products ranging from 237 to 429 bp were obtained from 92% of the clinical isolates. The remaining 8%, divided into groups with ITS2 regions which differed by ≤2 bp in mean length, all contained species-specific DNA sequences easily distinguishable by restriction enzyme analysis. These data, and the specificity of length polymorphisms for identifying yeasts, were confirmed by DNA sequence analysis of the ITS2 region from 93 isolates. Phenotypic and ITS2-based identification was concordant for 427 of 434 yeast isolates examined using sequence identity of ≥99%. Seven clinical isolates contained ITS2 sequences that did not agree with their phenotypic identification, and ITS2-based phylogenetic analyses indicate the possibility of new or clinically unusual species in the Rhodotorula and Candida genera. This work establishes an initial database, validated with over 400 clinical isolates, of ITS2 length and sequence polymorphisms for 34 species of yeasts. We conclude that size and restriction analysis of PCR-amplified ITS2 region DNA is a rapid and reliable method to identify clinically significant yeasts, including potentially new or emerging pathogenic species. PMID:10834993

Production, characterization, and antifungal activity of a biosurfactant produced by Rhodotorula babjevae YS3.

PubMed

Sen, Suparna; Borah, Siddhartha Narayan; Bora, Arijit; Deka, Suresh

2017-05-30

Sophorolipids are one of the most promising glycolipid biosurfactants and have been successfully employed in bioremediation and various other industrial sectors. They have also been described to exhibit antimicrobial activity against different bacterial species. Nevertheless, previous literature pertaining to the antifungal activity of sophorolipids are limited indicating the need for further research to explore novel strains with wide antimicrobial activity. A novel yeast strain, Rhodotorula babjevae YS3, was recently isolated from an agricultural field in Assam, Northeast India. This study was primarily emphasized at the characterization and subsequent evaluation of antifungal activity of the sophorolipid biosurfactant produced by R. babjevae YS3. The growth kinetics and biosurfactant production by R. babjevae YS3 was evaluated by cultivation in Bushnell-Haas medium containing glucose (10% w/v) as the sole carbon source. A reduction in the surface tension of the culture medium from 70 to 32.6 mN/m was observed after 24 h. The yield of crude biosurfactant was recorded to be 19.0 g/l which might further increase after optimization of the growth parameters. The biosurfactant was characterized to be a heterogeneous sophorolipid (SL) with both lactonic and acidic forms after TLC, FTIR and LC-MS analyses. The SL exhibited excellent oil spreading and emulsifying activity against crude oil at 38.46 mm 2 and 100% respectively. The CMC was observed to be 130 mg/l. The stability of the SL was evaluated over a wide range of pH (2-10), salinity (2-10% NaCl) and temperature (at 120 °C for time intervals of 30 up to 120 min). The SL was found to retain surface-active properties under the extreme conditions. Additionally, the SL exhibited promising antifungal activity against a considerably broad group of pathogenic fungi viz. Colletotrichum gloeosporioides, Fusarium verticilliodes, Fusarium oxysporum f. sp. pisi, Corynespora cassiicola, and Trichophyton rubrum. The

Effect of potential probiotic Rhodotorula benthica D30 on the growth performance, digestive enzyme activity and immunity in juvenile sea cucumber Apostichopus japonicus.

PubMed

Wang, Ji-hui; Zhao, Liu-qun; Liu, Jin-feng; Wang, Han; Xiao, Shan

2015-04-01

The effects of dietary addition of yeast Rhodotorula benthica (R. benthica) D30 which isolated from local sea mud at levels of 0 (control), 10(5), 10(6) and 10(7) CFU/g feed on the growth performance, digestive enzyme activity, immunity and disease resistance of juvenile sea cucumber Apostichopus japonicus were investigated. It was shown that dietary addition of R. benthica D30 significantly increased the growth rates of sea cucumbers (p < 0.05). The amylase activity, cellulase activity and alginase activity were increased for the animals from three probiotics treated groups. And with the supplemented concentration increased, the values of those digestive enzyme activities increased as well. Dietary addition of R. benthica D30 at the level of 10(7) CFU significantly increased the lysozyme, phagocytic and total nitric oxide synthase activity of A. japonicus (p < 0.05). While, the highest values of the phenoloxidase and alkaline phosphatase activity were found in sea cucumbers fed with R. benthica D30 at the level of 10(6) CFU. Whereas adding R. benthica D30 to diet had no significant effects on the total coelomocyte counts and acid phosphatase activity of A. japonicus (p > 0.05). It was observed that adding R. benthica D30 could significantly decrease the cumulative mortality of sea cucumbers. The present study demonstrated that dietary addition of R. benthica D30 could increase growth performance and some digestive enzyme activities, improve immunity and disease resistance of A. japonicus. And the medium (10(6) CFU) and high (10(7) CFU) additional levels showed better effects. It suggests that yeast R. benthica D30 could be a good probiotic for aquaculture. Copyright © 2015 Elsevier Ltd. All rights reserved.

Metal-Induced Production of a Novel Bioadsorbent Exopolysaccharide in a Native Rhodotorula mucilaginosa from the Mexican Northeastern Region.

PubMed

Garza-Gonzalez, Maria Teresa; Gonzalez Garza, Maria Teresa; Barboza Perez, Daniel; Vazquez Rodriguez, Augusto; Garcia-Gutierrez, Domingo Ixcoatl; Zarate, Xristo; Cantú Cardenas, Maria Elena; Urraca-Botello, Ludwing Ilytch; Lopez-Chuken, Ulrico Javier; Trevino-Torres, Alberto Ludovico; Cerino-Córdoba, Felipe de Jesus; Medina-Ruiz, Pavel; Villarreal-Chiu, Juan Francisco; Morones-Ramirez, Jose Ruben

2016-01-01

There is a current need to develop low-cost strategies to degrade and eliminate industrially used colorants discharged into the environment. Colorants discharged into natural water streams pose various threats, including: toxicity, degradation of aesthetics and inhibiting sunlight penetration into aquatic ecosystems. Dyes and colorants usually have complex aromatic molecular structures, which make them very stable and difficult to degrade and eliminate by conventional water treatment systems. The results in this work demonstrated that heavy metal-resistant Rhodotorula mucilaginosa strain UANL-001L isolated from the northeast region of Mexico produce an exopolysaccharide (EPS), during growth, which has colorant adsorption potential. The EPS produced was purified by precipitation and dialysis and was then physically and chemically characterized by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and chemical elemental analysis. Here, the ability of the purified EPS produced to adsorb methylene blue (MB), which served as a model colorant, is studied. MB adsorption by the EPS is found to follow Langmuir Adsorption Isotherm kinetics at 25°C. Further, by calculating the Langmuir constant the adsorption capabilities of the EPS produced by the Rhodotorula mucilaginosa strain UANL-001L is compared to that of other adsorbents, both, microbially produced and from agroindustrial waste. The total adsorption capacity of the EPS, from the Rhodotorula mucilaginosa strain UANL-001L, was found to be two-fold greater than the best bioadsorbents reported in the literature. Finally, apart from determining which heavy metals stimulated EPS production in the strain, the optimal conditions of pH, heavy metal concentration, and rate of agitation of the growing culture for EPS production, was determined. The EPS reported here has the potential of aiding in the efficient removal of colorants both in water treatment plants and in situ in natural water streams.

Metal-Induced Production of a Novel Bioadsorbent Exopolysaccharide in a Native Rhodotorula mucilaginosa from the Mexican Northeastern Region

PubMed Central

Vazquez Rodriguez, Augusto; Garcia-Gutierrez, Domingo Ixcoatl; Zarate, Xristo; Cantú Cardenas, Maria Elena; Urraca-Botello, Ludwing Ilytch; Lopez-Chuken, Ulrico Javier; Trevino-Torres, Alberto Ludovico; Cerino-Córdoba, Felipe de Jesus; Medina-Ruiz, Pavel; Villarreal-Chiu, Juan Francisco; Morones-Ramirez, Jose Ruben

2016-01-01

There is a current need to develop low-cost strategies to degrade and eliminate industrially used colorants discharged into the environment. Colorants discharged into natural water streams pose various threats, including: toxicity, degradation of aesthetics and inhibiting sunlight penetration into aquatic ecosystems. Dyes and colorants usually have complex aromatic molecular structures, which make them very stable and difficult to degrade and eliminate by conventional water treatment systems. The results in this work demonstrated that heavy metal-resistant Rhodotorula mucilaginosa strain UANL-001L isolated from the northeast region of Mexico produce an exopolysaccharide (EPS), during growth, which has colorant adsorption potential. The EPS produced was purified by precipitation and dialysis and was then physically and chemically characterized by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and chemical elemental analysis. Here, the ability of the purified EPS produced to adsorb methylene blue (MB), which served as a model colorant, is studied. MB adsorption by the EPS is found to follow Langmuir Adsorption Isotherm kinetics at 25°C. Further, by calculating the Langmuir constant the adsorption capabilities of the EPS produced by the Rhodotorula mucilaginosa strain UANL-001L is compared to that of other adsorbents, both, microbially produced and from agroindustrial waste. The total adsorption capacity of the EPS, from the Rhodotorula mucilaginosa strain UANL-001L, was found to be two-fold greater than the best bioadsorbents reported in the literature. Finally, apart from determining which heavy metals stimulated EPS production in the strain, the optimal conditions of pH, heavy metal concentration, and rate of agitation of the growing culture for EPS production, was determined. The EPS reported here has the potential of aiding in the efficient removal of colorants both in water treatment plants and in situ in natural water streams. PMID

Diversity, in-vitro virulence traits and antifungal susceptibility pattern of gastrointestinal yeast flora of healthy poultry, Gallus gallus domesticus.

PubMed

Subramanya, Supram Hosuru; Sharan, Nawal Kishor; Baral, Bharat Prasad; Hamal, Deependra; Nayak, Niranjan; Prakash, Peralam Yegneswaran; Sathian, Brijesh; Bairy, Indira; Gokhale, Shishir

2017-05-15

Poultry farming and consumption of poultry (Gallus gallus domesticus) meat and eggs are common gastronomical practices worldwide. Till now, a detailed understanding about the gut colonisation of Gallus gallus domesticus by yeasts and their virulence properties and drug resistance patterns in available literature remain sparse. This study was undertaken to explore this prevalent issue. A total of 103 specimens of fresh droppings of broiler chickens (commercial G domesticus) and domesticated chickens (domesticated G domesticus) were collected from the breeding sites. The isolates comprised of 29 (33%) Debaryozyma hansenii (Candida famata), 12 (13.6%) Sporothrix catenata (C. ciferrii), 10 (11.4%) C. albicans, 8 (9.1%) Diutnia catenulata (C. catenulate), 6 (6.8%) C. tropicalis, 3 (3.4%) Candida acidothermophilum (C. krusei), 2 (2.3%) C. pintolopesii, 1 (1.1%) C. parapsilosis, 9 (10.2%) Trichosporon spp. (T. moniliiforme, T. asahii), 4 (4.5%) Geotrichum candidum, 3 (3.4%) Cryptococcus macerans and 1 (1%) Cystobasidium minuta (Rhodotorula minuta). Virulence factors, measured among different yeast species, showed wide variability. Biofilm cells exhibited higher Minimum Inhibitory Concentration (MIC) values (μg/ml) than planktonic cells against all antifungal compounds tested: (fluconazole, 8-512 vs 0.031-16; amphotericin B, 0.5-64 vs 0.031-16; voriconazole 0.062-16 vs 0.062-8; caspofungin, 0.062-4 vs 0.031-1). The present work extends the current understanding of in vitro virulence factors and antifungal susceptibility pattern of gastrointestinal yeast flora of G domesticus. More studies with advanced techniques are needed to quantify the risk of spread of these potential pathogens to environment and human.

First report of sporadic cases of Candida auris in Colombia.

PubMed

Parra-Giraldo, Claudia M; Valderrama, Sandra L; Cortes-Fraile, Gloria; Garzón, Javier R; Ariza, Beatriz E; Morio, Florent; Linares-Linares, Melva Y; Ceballos-Garzón, Andrés; de la Hoz, Alejandro; Hernandez, Catalina; Alvarez-Moreno, Carlos; Le Pape, Patrice

2018-04-01

Candida auris is a recently reported Candida species that is phenotypically similar to Candida haemulonii and related to hospital outbreaks. This organism can be misidentified as Candida haemulonii, Candida famata, Candida catenulata, or Rhodotorula glutinis by phenotypic approaches. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and DNA sequence analysis using internal transcribed spacer rDNA bar-coding provide an accurate identification. Three cases of C. auris infection in patients with risk factors for fungal infection (one admitted to the intensive care unit, one with lymphoma, and one with HIV; all three with previous antibiotic use) are reported; these infections were not epidemiologically related. Yeast isolates were recovered from blood, ocular secretion, and bronchoalveolar lavage and were misidentified as C. catenulata and Candida albicans by the phenotypic MicroScan method. The isolates were confirmed to be C. auris by means of MALDI-TOF MS and DNA sequence analysis. Antifungal susceptibility testing was performed on these C. auris isolates, which exhibited high minimum inhibitory concentrations to triazoles and amphotericin B. One patient survived and the other two died. Only one of these deaths was related to fungemia. C. auris is an emerging and opportunistic multidrug-resistant human pathogen. It is necessary to strengthen measures to achieve an accurate and quick identification and also to avoid its dissemination. This will require improvements in health and infection control measures, as well as the promotion of antifungal stewardship in healthcare facilities. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Antimicrobial activity of broccoli (Brassica oleracea var. italica) cultivar Avenger against pathogenic bacteria, phytopathogenic filamentous fungi and yeast.

PubMed

Pacheco-Cano, R D; Salcedo-Hernández, R; López-Meza, J E; Bideshi, D K; Barboza-Corona, J E

2018-01-01

The objective of this study was to show whether the edible part of broccoli has antibacterial and antifungal activity against micro-organism of importance in human health and vegetable spoilage, and to test if this effect was partially due to antimicrobial peptides (AMPs). Crude extracts were obtained from florets and stems of broccoli cultivar Avenger and the inhibitory effect was demonstrated against pathogenic bacteria (Bacillus cereus, Staphylococcus xylosus, Staphylococcus aureus, Shigella flexneri, Shigella sonnei, Proteus vulgaris), phytopathogenic fungi (Colletotrichum gloeosporioides, Asperigillus niger) and yeasts (Candida albicans and Rhodotorula sp.). It was shown that samples treated with proteolytic enzymes had a reduction of approximately 60% in antibacterial activity against Staph. xylosus, suggesting that proteinaceous compounds might play a role in the inhibitory effect. Antimicrobial components in crude extracts were thermoresistant and the highest activity was observed under acidic conditions. It was shown that antifungal activity of broccoli's crude extracts might not be attributed to chitinases. Organic broccoli cultivar Avenger has antimicrobial activity against pathogenic bacteria, yeast and phytophatogenic fungi. Data suggest that this effect is partially due to AMPs. Broccoli's crude extracts have activity not only against pathogenic bacteria but also against phytophatogenic fungi of importance in agriculture. We suggest for first time that the inhibitory effect is probably due to AMPs. © 2017 The Society for Applied Microbiology.

Sympodiomycopsis lanaiensis sp. nov., a basidiomycetous yeast (Ustilaginomycotina: Microstromatales) from marine driftwood in Hawai‘i

PubMed Central

Mahdi, Leena E.; Statzell-Tallman, Adele; Fell, Jack W.; Brown, Mark V.; Donachie, Stuart P.

2009-01-01

A previously unknown basidiomycetous yeast is described for which the name Sympodiomycopsis lanaiensis is proposed. The type strain, LM418T, was isolated from driftwood collected on a beach on Lana‘i (Hawai‘i). On the basis of ribosomal DNA sequence analysis [large subunit (LSU), internal transcribed spacer (ITS) 1 & 2, and 18S], LM418T belongs to the order Microstromatales, which includes the genera Sympodiomycopsis, Rhodotorula, Microstroma, Volvocisporium and Quambalaria. The strain is described as a new species in the genus Sympodiomycopsis on the basis of morphological and physiological characteristics and the phylogenetic relationship to Sympodiomycopsis paphiopedili. Sexual reproduction was not observed in LM418T. GenBank accession numbers for nucleotide sequences of regions of the LSU, ITS and 18S regions of the ribosomal operon in LM418T are DQ990016, DQ990017 and DQ990018, respectively. LM418T has been deposited in the DSMZ as DSM 18755, in the ATCC as MYA-4092, in the Agricultural Research Service Culture Collection as NRRL Y-48466, and the Centraalbureau voor Schimmelcultures as CBS 10858. PMID:19054136

Interplay between carotenoids, hemoproteins and the "life band" origin studied in live Rhodotorula mucilaginosa cells by means of Raman microimaging.

PubMed

Pacia, Marta Z; Turnau, Katarzyna; Baranska, Malgorzata; Kaczor, Agnieszka

2015-03-21

Raman microimaging of live Rhodotorula mucilaginosa cells, cultured under aerobic and anaerobic conditions, showed striking differences in the composition and distribution of cell components. The analysis of these differences and recovery of oxidative phosphorylation upon environmental changes enabled the interrelation of carotenoids, hemoproteins and the unknown species considered as the "Raman signature of life".

The Black Yeast Exophiala dermatitidis and Other Selected Opportunistic Human Fungal Pathogens Spread from Dishwashers to Kitchens

PubMed Central

Zupančič, Jerneja; Novak Babič, Monika; Zalar, Polona; Gunde-Cimerman, Nina

2016-01-01

We investigated the diversity and distribution of fungi in nine different sites inside 30 residential dishwashers. In total, 503 fungal strains were isolated, which belong to 10 genera and 84 species. Irrespective of the sampled site, 83% of the dishwashers were positive for fungi. The most frequent opportunistic pathogenic species were Exophiala dermatitidis, Candida parapsilosis sensu stricto, Exophiala phaeomuriformis, Fusarium dimerum, and the Saprochaete/Magnusiomyces clade. The black yeast E. dermatitidis was detected in 47% of the dishwashers, primarily at the dishwasher rubber seals, at up to 106 CFU/cm2; the other fungi detected were in the range of 102 to 105 CFU/cm2. The other most heavily contaminated dishwasher sites were side nozzles, doors and drains. Only F. dimerum was isolated from washed dishes, while dishwasher waste water contained E. dermatitidis, Exophiala oligosperma and Sarocladium killiense. Plumbing systems supplying water to household appliances represent the most probable route for contamination of dishwashers, as the fungi that represented the core dishwasher mycobiota were also detected in the tap water. Hot aerosols from dishwashers contained the human opportunistic yeast C. parapsilosis, Rhodotorula mucilaginosa and E. dermatitidis (as well as common air-borne genera such as Aspergillus, Penicillium, Trichoderma and Cladosporium). Comparison of fungal contamination of kitchens without and with dishwashers revealed that virtually all were contaminated with fungi. In both cases, the most contaminated sites were the kitchen drain and the dish drying rack. The most important difference was higher prevalence of black yeasts (E. dermatitidis in particular) in kitchens with dishwashers. In kitchens without dishwashers, C. parapsilosis strongly prevailed with negligible occurrence of E. dermatitidis. F. dimerum was isolated only from kitchens with dishwashers, while Saprochaete/Magnusiomyces isolates were only found within dishwashers. We

Development of nitrocellulose membrane filters impregnated with different biosynthesized silver nanoparticles applied to water purification.

PubMed

Fernández, Jorge G; Almeida, César A; Fernández-Baldo, Martín A; Felici, Emiliano; Raba, Julio; Sanz, María I

2016-01-01

Bactericidal water filters were developed. For this purpose, nitrocellulose membrane filters were impregnated with different biosynthesized silver nanoparticles. Silver nanoparticles (AgNPs) from Aspergillus niger (AgNPs-Asp), Cryptococcus laurentii (AgNPs-Cry) and Rhodotorula glutinis (AgNPs-Rho) were used for impregnating nitrocellulose filters. The bactericidal properties of these nanoparticles against Escherichia coli, Enterococcus faecalis and Pseudomona aeruginosa were successfully demonstrated. The higher antimicrobial effect was observed for AgNPs-Rho. This fact would be related not only to the smallest particles, but also to polysaccharides groups that surrounding these particles. Moreover, in this study, complete inhibition of bacterial growth was observed on nitrocellulose membrane filters impregnated with 1 mg L(-1) of biosynthesized AgNPs. This concentration was able to reduce the bacteria colony count by over 5 orders of magnitude, doing suitable for a water purification device. Copyright © 2015 Elsevier B.V. All rights reserved.

Antimicrobial activity of α-(2-hydroxy-2-methylpropyl)-ω-(2-hydroxy-3-methylbut-2-en-1-yl) polymethylene from caesalpinia bonducella (L.) Flem

PubMed Central

Sagar, Kavitha; Vidyasagar, G. M.

2010-01-01

The compound, α-(2-hydroxy-2-methylpropyl)-ω-(2-hydroxy-3-methylbut-2-en-1-yl)polymethylene, isolated from ethyl acetate leaf extract of Caesalpinia bonducella (L.) Flem. was evaluated for antimicrobial activity against clinical isolates, Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella sp., Staphylococcus citrus, Staphylococcus aureus, Escherichia coli, Candida albicans and Rhodotorula sp. using agar diffusion method. The compound exerted inhibitory zone at all concentrations and revealed the concentration-dependent activity against all tested bacterial and yeast strains comparable to standards streptomycin sulphate and gentamycin for bacteria and fluconazole and griseofulvin for Candida albicans and Rhodotorula sp. The inhibition zones were wider and clear for C. albicans and Rhodotorula sp. (IZ >20 mm) and for Pseudomonas aeruginosa, P. vulgaris and E. coli zones were greater than standards tested, whereas, zones for Klebsiella sp. and S. aureus were similar to standards. PMID:21218063

Influence of high power ultrasound on selected moulds, yeasts and Alicyclobacillus acidoterrestris in apple, cranberry and blueberry juice and nectar.

PubMed

Režek Jambrak, Anet; Šimunek, Marina; Evačić, Silva; Markov, Ksenija; Smoljanić, Goran; Frece, Jadranka

2018-02-01

The purpose of this study was to investigate the effect of non-thermal technology, high power ultrasound (HPU) on inactivation of Aspergillus ochraceus 318, Penicillium expansum 565, Rhodotorula sp. 74, Saccharomyces cerevisiae 5 and Alicyclobacillus acidoterrestris DSM 3922 in clear juices and nectars from apple, blueberry and cranberry juice concentrate. Inoculated juice and nectars were treated by high power ultrasound (20kHz) according to procedure set by central composite design (CCD). Three operational parameters, amplitude (60, 90 and 120μm), temperature (20, 40 and 60°C), and treatment time (3, 6 or 9min) were varied in order to observe the influence of ultrasound and combination of ultrasound and slight heating (thermosonication) on growth and inactivation of selected microorganisms. Number of vegetative cells of A. acidoterrestris DSM 3922 were not significantly reduced by high power ultrasound (p>0.05), except in apple juice, where statistical significant (p<0.05) influence of quadratic interaction of amplitude on bacteria reduction were observed. In all samples of fruit juices and nectars in terms of ultrasonic treatment at 60°C and times of 3, 6 and 9min, regardless of the value of the amplitude, complete inactivation of the growth of yeasts and moulds were achieved, while at 20 and 40°C it is not observed. The value of reduction of cells of selected yeasts and moulds for ultrasound treatments at 60°C and the duration of the 3, 6 and 9min ranged from 3.556 to 5.934 log units, depending on the initial number of selected yeasts and moulds before treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Degradation capacities of bacteria and yeasts isolated from the gut of Dendroctonus rhizophagus (Curculionidae: Scolytinae).

PubMed

Briones-Roblero, Carlos I; Rodríguez-Díaz, Roberto; Santiago-Cruz, José A; Zúñiga, Gerardo; Rivera-Orduña, Flor N

2017-01-01

Bark beetles (Curculionidae: Scolytinae) feed on the xylem and phloem of their host, which are composed of structural carbohydrates and organic compounds that are not easily degraded by the insects. Some of these compounds might be hydrolyzed by digestive enzymes produced by microbes present in the gut of these insects. In this study, we evaluated the enzymatic capacity of bacteria (Acinetobacter lwoffii, Arthrobacter sp., Pseudomonas putida, Pseudomonas azotoformans, and Rahnella sp.) and yeasts (Candida piceae, Candida oregonensis, Cyberlindnera americana, Zygoascus sp., and Rhodotorula mucilaginosa) isolated from the Dendroctonus rhizophagus gut to hydrolyze cellulose, xylan, pectin, starch, lipids, and esters. All isolates, with the exception of C. piceae, showed lipolytic activity. Furthermore, P. putida, P. azotoformans, C. americana, C. piceae, and R. mucilaginosa presented amylolytic activity. Esterase activity was shown by A. lwoffii, P. azotoformans, and Rahnella sp. Cellulolytic and xylanolytic activities were present only in Arthrobacter sp. and P. azotoformans. The pectinolytic activity was not recorded in any isolate. This is the first study to provide evidence on the capacity of microbes associated with the D. rhizophagus gut to hydrolyze specific substrates, which might cover part of the nutritional requirements for the development, fitness, and survival of these insects.

Biocontrol Agents Increase the Specific Rate of Patulin Production by Penicillium expansum but Decrease the Disease and Total Patulin Contamination of Apples

PubMed Central

Zheng, Xiangfeng; Yang, Qiya; Zhang, Xiaoyun; Apaliya, Maurice T.; Ianiri, Giuseppe; Zhang, Hongyin; Castoria, Raffaello

2017-01-01

Synthetic fungicides are commonly employed for the control of postharvest diseases of fruits. However, due to health concerns about the use of these chemicals, alternative control methods including biocontrol based on antagonistic yeasts are gaining in popularity. In this study, we investigated the effects of two biocontrol yeasts, Rhodotorula mucilaginosa strain 3617 and Rhodotorula kratochvilovae strain LS11, on blue mold and patulin (PAT) contamination caused by Penicillium expansum strains PY and FS7 in artificially inoculated Fuji apples stored at 20°C for 9 days. To correlate the development of the P. expansum strains in yeast-treated and untreated apples with PAT production, we quantified their biomass in the infected fruits using a recently published quantitative real-time polymerase chain reaction method based on specific primers for patF, a gene from P. expansum that is involved in PAT biosynthesis. Both yeasts significantly reduced the disease incidence caused by the two strains of P. expansum up to 5–7 days of incubation, and lowered their biomass and the progression of symptoms up to 9 days. Interestingly, both yeasts strains increased the rate of PAT production (expressed as ng patulin/μg fungal DNA) by the two pathogenic strains. Nevertheless, both biocontrol agents reduced the total PAT contamination, especially in the case of P. expansum strain FS7, the higher PAT producer of the two tested P. expansum strains. Comparing between the yeast strains, R. kratochvilovae LS11 was more effective than R. mucilaginosa 3617 for the control of P. expansum. PMID:28713362

Secondary successions of biota in oil-polluted peat soil upon different biological remediation methods

NASA Astrophysics Data System (ADS)

Melekhina, E. N.; Markarova, M. Yu.; Shchemelinina, T. N.; Anchugova, E. M.; Kanev, V. A.

2015-06-01

The effects of different bioremediation methods on restoration of the oil-polluted peat soil (Histosol) in the northernmost taiga subzone of European Russia was studied. The population dynamics of microorganisms belonging to different trophic groups (hydrocarbon-oxidizing, ammonifying, nitrifying, and oligonitrophilic) were analyzed together with data on the soil enzyme (catalase and dehydrogenase) activities, population densities of soil microfauna groups, their structures, and states of phytocenoses during a sevenyear-long succession. The remediation with biopreparations Roder composed of oil-oxidizing microorganisms-Roder with Rhodococcus rubber and R. erythropolis and Universal with Rhodotorula glutinis and Rhodococcus sp.-was more efficient than the agrochemical and technical remediation. It was concluded that the biopreparations activate microbiological oil destruction, thereby accelerating restoration succession of phytocenosis and zoocenosis. The succession of dominant microfauna groups was observed: the dipteran larvae and Mesostigmata mites predominant at the early stages were replaced by collembolans at later stages. The pioneer oribatid mite species were Tectocepheus velatus, Oppiella nova, Liochthonius sellnicki, Oribatula tibialis, and Eupelops sp.

[Evaluation of common commercial systems for the identification of yeast isolates in microbiology laboratories: a multicenter study].

PubMed

Karabıçak, Nilgün; Uludağ Altun, Hatice; Karatuna, Onur; Hazırolan, Gülşen; Aksu, Neriman; Adiloğlu, Ali; Akyar, Işın

2015-04-01

Accurate and rapid identification of yeast isolates have become important in recent years for not only antifungal susceptibility testing due to the species-specific clinical resistance breakpoints but also early initiation of appropriate antifungal therapy. In clinical microbiology laboratories species identification of yeasts is often performed with several commercial systems based on biochemical properties and rarely according to the physiological and morphological characteristics. The aim of this study was to compare the two common commercial systems, VITEK 2 YST ID Card (Vitek; bioMérieux, France) and API 20C AUX (API; bioMérieux, France) with conventional mycological methods. A total of 473 clinical yeast strains isolated from clinical specimens in different university and training/research hospitals and identified by Vitek system were included in the study. The isolates were re-identified with API and conventional methods including morphological identification in the Mycology Reference Laboratory of the Public Health Institute of Turkey. Candida dubliniensis MYA 583, Candida krusei ATCC 6258, Candida parapsilosis ATCC 22019, Candida albicans ATCC 10231 and Cryptococcus neoformans ATCC 32268 were used as quality control strains and those standard strains were studied consecutively 10 days with both of the methods. The results of identification by Vitek and API were compared with the results of conventional methods for those 473 yeast isolates [6 genus (Candida, Cryptococcus, Blastoshizomyces, Rhodotorula, Saccharomyces, Trichosporon), 17 species (5 common and 12 rarely isolated)]. The performances of the systems were better (Vitek: 95%; API: 96%) for the commonly detected species (C.albicans, C.parapsilosis, C.glabrata, C.tropicalis and C.krusei) than those for rarely detected species (Vitek: 78.4%; API: 71.6%) (p= 0.155). Misidentification or unidentification were mostly detected for C.parapsilosis (Vitek: 6/87; API: 7/87) and C.glabrata (Vitek: 9/104; API

Yeast Based Sensors

NASA Astrophysics Data System (ADS)

Shimomura-Shimizu, Mifumi; Karube, Isao

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.

In vitro activity of natural honey alone and in combination with curcuma starch against Rhodotorula mucilaginosa in correlation with bioactive compounds and diastase activity

PubMed Central

Ahmed, Moussa; Djebli, Noureddine; Aissat, Saad; Khiati, Baghdad; Meslem, Abdelmalek; Bacha, Salima

2013-01-01

Objective To evaluate the in vitro activity and synergism of the combinations of natural honey and curcuma starch against Rhodotorula mucilaginosa in correlation with total phenolic, flavonoid contents, and diastase activity. Methods The Folin-Ciocalteu test was used to determine the total polyphenols content and the flavonoid content was analyzed using by the aluminum chloride method. The antifungal activity of the natural honey, determined by an agar well diffusion assay and agar incorporation method. Results Total phenolic content varied from (63.93±0.11) to (95.36±6.08) mg GAE/100 g honey as gallic acid equivalent. Total flavonoids content varied from (5.41±0.04) to (9.94±0.54) mg CE/100 g. Diastase activity values were between (7.3±2.8) and (26±2.8). The zone inhibition diameter for the six honey samples without starch ranged between 6 and 20 mm. When starch was mixed with honey and then added to well, a zone inhibition increase diameter 7 and 21 mm. The percentage increase was noticed with each variety and it ranged between 5% and 62.5%. The minimal inhibitory concentrations for the six varieties of honey without starch against Rhodotorula mucilaginosa ranged between 28% and 36% (v/v). When starch was incubated with honey and then added to media, a minimal inhibitory concentration drop has been noticed with each variety. It ranged between 6.66 % and 20% (w/v). No significant correlation was established between diastase activity and bioactive compounds. Conclusions The mixture of curcuma starch and honey could lead to the development of new combination antibiotics against Rhodotorula infections PMID:24075348

A novel extracellular glycosidase activity from Rhodotorula mucilaginosa: its application potential in wine aroma enhancement.

PubMed

Hu, K; Zhu, X L; Mu, H; Ma, Y; Ullah, N; Tao, Y S

2016-02-01

The aim of the work was to evaluate the application potential of a glycosidase extract of one indigenous non-Saccharomyces strain in wine aroma enhancement. The isolate was selected from a local winemaking region in China for its high β-glucosidase level and was identified as Rhodotorula mucilaginosa. The tolerance of the glycosidase extract to the typical winemaking conditions was assessed using the activity of its β-glucosidase. After that, the hydrolysis capacity of R. mucilaginosa glycosidase for liberation of grape aroma glycosides was characterized in comparison to commercial enzyme preparations. Results of this work revealed that glycosidase extract from R. mucilaginosa proved to be active in the presence of 0-20% (w/v) glucose, 0-20% (v/v) ethanol and at pH 3·0-5·0. In the hydrolysis of aroma precursors, enzymes obtained from different origins possessed various levels of specificity and activity, showing high origin dependence (α = 0·05). Compared to commercial enzymes, the indigenous R. mucilaginosa glycosidase extract presented better catalytic preference for the 'fruity and floral' glycosides of benzenic compounds and C13 -norisoprenoids, but less sensitivity to the glycosides of C6 compounds and volatile phenols. This work presents a novel extracellular glycosidase preparation from an indigenous Rhodotorula mucilaginosa strain selected from a local winemaking region in China. This enzyme extract exhibits strong tolerance towards winemaking conditions. It shows hydrolysis specificity for glycosides of benzenic compounds and C13 -norisoprenoids, proving a potential candidate for improving floral and fruity aroma characteristics of wine. © 2015 The Society for Applied Microbiology.

Biotechnological methods for chalcone reduction using whole cells of Lactobacillus, Rhodococcus and Rhodotorula strains as a way to produce new derivatives.

PubMed

Stompor, Monika; Kałużny, Mateusz; Żarowska, Barbara

2016-10-01

Microbial strains of the genera Dietzia, Micrococcus, Pseudomonas, Rhodococcus, Gordonia, Streptomyces, Pseudomonas, Bacillus, Penicillium, Rhodotorula and Lactobacillus were screened for the ability to convert chalcones. Synthesis of chalcones was performed by the Claisen-Schmidt reaction. There were three groups of chalcones obtained as the products, which included the derivatives containing 4-substituted chalcone, 2'-hydroxychalcone and 4'-methoxychalcone. The B ring of the chalcones was substituted in the para position with different groups, such as halide, hydroxyl, nitro, methyl, ethyl and ethoxy one. The structure-activity relationship of the tested chalcones in biotransformation processes was studied. It has been proven that Gram-positive bacterial strains Rhodococcus and Lactobacillus catalyzed reduction of C=C bond in the chalcones to give respective dihydrochalcones. The strain Rhodotorula rubra AM 82 transformed chalcones into dihydrochalcones and respective secondary alcohols. These results suggest that the probiotic strain of Lactobacillus can be used for biotransformations of chalcones, which has not been described before. The structure of new metabolites 14a and 15b were established as 4-ethoxy-4'-methoxydihydrochalcone and 3-(4-bromophenyl)-1-(4'-O-methylphenyl)-2-propan-1-ol, respectively, which was confirmed by (1)H NMR and (13)C NMR analysis.

[Fungal peritonitis due to Rhodotorula mucilaginosa in a patient with automated peritoneal dialysis: Literature review].

PubMed

Verdugo, Fernando J; Briones, Eduardo; Porte, Lorena; Amaro, José; Fica, Alberto

2016-04-01

Fungal peritonitis is a major complication of peritoneal dialysis associated with high mortality. Most survivors have a high rate of abandonment of peritoneal dialysis. We report a case of fungal peritonitis due to an unusual agent. An 83 year-old woman, with a history of type 2 diabetes mellitus and multiple episodes of bacterial peritonitis associated to technical flaws in the implementation of automated peritoneal dialysis, was admitted due to abdominal pain and cloudy peritoneal fluid. Rhodotorula mucilaginosa was identified in the peritoneal fluid by MALDI-TOF. She was treated with catheter removal and oral posaconazole for 14 days showing clinical resolution and non-recurrence.

Extracellular Polysaccharides Produced by Yeasts and Yeast-Like Fungi

NASA Astrophysics Data System (ADS)

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

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.

Yeast Infection (Vaginal)

MedlinePlus

Yeast infection (vaginal) Overview A vaginal yeast infection is a fungal infection that causes irritation, discharge and intense itchiness ... symptoms Causes The fungus candida causes a vaginal yeast infection. Your vagina naturally contains a balanced mix of yeast, including ...

Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts.

PubMed

Gonçalves, Margarida; Pontes, Ana; Almeida, Pedro; Barbosa, Raquel; Serra, Marta; Libkind, Diego; Hutzler, Mathias; Gonçalves, Paula; Sampaio, José Paulo

2016-10-24

Beer is one of the oldest alcoholic beverages and is produced by the fermentation of sugars derived from starches present in cereal grains. Contrary to lager beers, made by bottom-fermenting strains of Saccharomyces pastorianus, a hybrid yeast, ale beers are closer to the ancient beer type and are fermented by S. cerevisiae, a top-fermenting yeast. Here, we use population genomics to investigate (1) the closest relatives of top-fermenting beer yeasts; (2) whether top-fermenting yeasts represent an independent domestication event separate from those already described; (3) whether single or multiple beer yeast domestication events can be inferred; and (4) whether top-fermenting yeasts represent non-recombinant or recombinant lineages. Our results revealed that top-fermenting beer yeasts are polyphyletic, with a main clade composed of at least three subgroups, dominantly represented by the German, British, and wheat beer strains. Other beer strains were phylogenetically close to sake, wine, or bread yeasts. We detected genetic signatures of beer yeast domestication by investigating genes previously linked to brewing and using genome-wide scans. We propose that the emergence of the main clade of beer yeasts is related with a domestication event distinct from the previously known cases of wine and sake yeast domestication. The nucleotide diversity of the main beer clade more than doubled that of wine yeasts, which might be a consequence of fundamental differences in the modes of beer and wine yeast domestication. The higher diversity of beer strains could be due to the more intense and different selection regimes associated to brewing. Copyright © 2016 Elsevier Ltd. All rights reserved.

In vitro activity of natural honey alone and in combination with curcuma starch against Rhodotorula mucilaginosa in correlation with bioactive compounds and diastase activity.

PubMed

Ahmed, Moussa; Djebli, Noureddine; Aissat, Saad; Khiati, Baghdad; Meslem, Abdelmalek; Bacha, Salima

2013-10-01

To evaluate the in vitro activity and synergism of the combinations of natural honey and curcuma starch against Rhodotorula mucilaginosa in correlation with total phenolic, flavonoid contents, and diastase activity. The Folin-Ciocalteu test was used to determine the total polyphenols content and the flavonoid content was analyzed using by the aluminum chloride method. The antifungal activity of the natural honey, determined by an agar well diffusion assay and agar incorporation method. Total phenolic content varied from (63.930.11) to (95.366.08) mg GAE/100 g honey as gallic acid equivalent. Total flavonoids content varied from (5.41±0.04) to (9.94±0.54) mg CE/100 g. Diastase activity values were between (7.3±2.8) and (26±2.8). The zone inhibition diameter for the six honey samples without starch ranged between 6 and 20 mm. When starch was mixed with honey and then added to well, a zone inhibition increase diameter 7 and 21 mm. The percentage increase was noticed with each variety and it ranged between 5% and 62.5%. The minimal inhibitory concentrations for the six varieties of honey without starch against Rhodotorula mucilaginosa ranged between 28% and 36% (v/v). When starch was incubated with honey and then added to media, a minimal inhibitory concentration drop has been noticed with each variety. It ranged between 6.66 % and 20% (w/v). No significant correlation was established between diastase activity and bioactive compounds. The mixture of curcuma starch and honey could lead to the development of new combination antibiotics against Rhodotorula infections. Copyright © 2013 Asian Pacific Tropical Biomedical Magazine. Published by Elsevier B.V. All rights reserved.

Heat shock improves stress tolerance and biocontrol performance of Rhodotorula mucilaginosa

USDA-ARS?s Scientific Manuscript database

Biological control of postharvest diseases, utilizing wild species and strains of antagonistic yeasts, is a research topic and eco-friendly management approach that has received considerable attention. A few yeast-based biocontrol products are available in the market. Ecological fitness, stress to...

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

PubMed Central

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

2012-01-01

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

Taxonomic characterization, adaptation strategies and biotechnological potential of cryophilic yeasts from ice cores of Midre Lovénbreen glacier, Svalbard, Arctic.

PubMed

Singh, Purnima; Tsuji, Masaharu; Singh, Shiv Mohan; Roy, Utpal; Hoshino, Tamotsu

2013-04-01

Ten strains of cryophilic yeast were studied from glacier ice cores of Svalbard, Arctic. The ice melt samples contained about 3×10(3) - 1×10(4) colony forming unit (CFUs) per ml. Sequence analysis of the isolates, using D1/D2 domain identified five species of yeasts: Cryptococcus adeliensis (MLB-18 JX192655), Cryptococcus albidosimilis (MLB-19 JX192656), Cryptococcus saitoi (MLB-22 JX192659), Rhodosporidium lusitaniae (MLB-20 JX192657), and Rhodotorula mucilaginosa (MLB-27 JX192664). Effect of temperature on growth of these isolates was studied. The strains are able to grow at temperatures ranging between 1 and 20°C. Screening of the cultures for amylase, cellulase, protease, lipase, urease and catalase activity were carried out indicating varying amounts of enzyme production at different temperatures. Characterization of lipase in strain Cryptococcus sp. MLB-24 was performed. Fatty acid methyl ester (FAME) analysis of the cultures grown at four different temperatures (1, 4, 15, and 20°C) was also done. Decrease in temperature was reported to cause increase in concentration of unsaturated fatty acids. High amount of oleic acid accumulated with increase in temperature. These fatty acids possibly help the strains to survive in glacial ice core cold environment. The extracellular and intracellular filtrate of the cultures showed negative antifreeze protein (AFP) activity. The observations indicate that probably the isolates in the present undertaking adapt to low temperatures, by enzyme and PUFA secretion rather than by antifreeze protein secretion. Copyright © 2013 Elsevier Inc. All rights reserved.

Prions in Yeast

PubMed Central

Liebman, Susan W.; Chernoff, Yury O.

2012-01-01

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-β 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

Cross-linked enzyme aggregates of phenylalanine ammonia lyase: novel biocatalysts for synthesis of L-phenylalanine.

PubMed

Cui, Jian-Dong; Zhang, Si; Sun, Li-Mei

2012-06-01

Cross-linked enzyme aggregates of phenylalanine ammonia lyase (PAL-CLEAs) from Rhodotorula glutinis were prepared. The effects of the type of aggregating agent, its concentration, and that of cross-linking agent were studied. PAL-CLEAs production was most effective using ammonium sulfate (40 % saturation), followed by cross-linking for 1 h with 0.2 % (v/v) glutaraldehyde. Moreover, the storage and operational stability of the resulting PAL-CLEAs were also investigated. Compared to the free enzyme, the PAL-CLEAs exhibited the expected increased stability of the enzyme against various deactivating conditions such as pH, temperature, denaturants, and organic solvents and showed higher storage stability than its soluble counterpart. Additionally, the reusability of PAL-CLEAs with respect to the biotransformation of L-phenylalanine was evaluated. PAL-CLEAs could be recycled at least for 12 consecutive batch reactions without dramatic activity loss, which should dramatically increase the commercial potential of PAL for synthesis of L: -phenylalanine. To the best of our knowledge, this is the first report of immobilization of PAL as cross-linked enzyme aggregates.

Yeast for virus research

PubMed Central

Zhao, Richard Yuqi

2017-01-01

Budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) are two popular model organisms for virus research. They are natural hosts for viruses as they carry their own indigenous viruses. Both yeasts have been used for studies of plant, animal and human viruses. Many positive sense (+) RNA viruses and some DNA viruses replicate with various levels in yeasts, thus allowing study of those viral activities during viral life cycle. Yeasts are single cell eukaryotic organisms. Hence, many of the fundamental cellular functions such as cell cycle regulation or programed cell death are highly conserved from yeasts to higher eukaryotes. Therefore, they are particularly suited to study the impact of those viral activities on related cellular activities during virus-host interactions. Yeasts present many unique advantages in virus research over high eukaryotes. Yeast cells are easy to maintain in the laboratory with relative short doubling time. They are non-biohazardous, genetically amendable with small genomes that permit genome-wide analysis of virologic and cellular functions. In this review, similarities and differences of these two yeasts are described. Studies of virologic activities such as viral translation, viral replication and genome-wide study of virus-cell interactions in yeasts are highlighted. Impacts of viral proteins on basic cellular functions such as cell cycle regulation and programed cell death are discussed. Potential applications of using yeasts as hosts to carry out functional analysis of small viral genome and to develop high throughput drug screening platform for the discovery of antiviral drugs are presented. PMID:29082230

L-arabinose fermenting yeast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Min; Singh, Arjun; Suominen, Pirkko

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. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

L-arabinose fermenting yeast

DOEpatents

Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

2014-09-23

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. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

Prevention of Yeast Spoilage in Feed and Food by the Yeast Mycocin HMK

PubMed Central

Lowes, K. F.; Shearman, C. A.; Payne, J.; MacKenzie, D.; Archer, D. B.; Merry, R. J.; Gasson, M. J.

2000-01-01

The yeast Williopsis mrakii produces a mycocin or yeast killer toxin designated HMK; this toxin exhibits high thermal stability, high pH stability, and a broad spectrum of activity against other yeasts. We describe construction of a synthetic gene for mycocin HMK and heterologous expression of this toxin in Aspergillus niger. Mycocin HMK was fused to a glucoamylase protein carrier, which resulted in secretion of biologically active mycocin into the culture media. A partial purification protocol was developed, and a comparison with native W. mrakii mycocin showed that the heterologously expressed mycocin had similar physiological properties and an almost identical spectrum of biological activity against a number of yeasts isolated from silage and yoghurt. Two food and feed production systems prone to yeast spoilage were used as models to assess the ability of mycocin HMK to act as a biocontrol agent. The onset of aerobic spoilage in mature maize silage was delayed by application of A. niger mycocin HMK on opening because the toxin inhibited growth of the indigenous spoilage yeasts. This helped maintain both higher lactic acid levels and a lower pH. In yoghurt spiked with dairy spoilage yeasts, A. niger mycocin HMK was active at all of the storage temperatures tested at which yeast growth occurred, and there was no resurgence of resistant yeasts. The higher the yeast growth rate, the more effective the killing action of the mycocin. Thus, mycocin HMK has potential applications in controlling both silage spoilage and yoghurt spoilage caused by yeasts. PMID:10698773

Effect of wine yeast monoculture practice on the biodiversity of non-Saccharomyces yeasts.

PubMed

Ganga, M A; Martínez, C

2004-01-01

The objective of this work was to study the effect of the use of Saccharomyces cerevisiae monocultures over the biodiversity of non-Saccharomyces yeasts in wine-producing areas in Chile. Microvinifications were carried out with grape musts of two areas. In one of them, the fermentation is carried out mainly in a spontaneous manner, whereas in the other the musts are inoculated with commercial yeasts. The isolated yeasts were identified by the internal transcribed (ITS)/restriction fragment length polymorphism technique. In the industrial production area less variability of yeast genera was observed as compared with the traditional area, an observation that is greatest at the end of the fermentation. Furthermore, a study of the production of extracellular enzymes was done. The majority of the yeasts showed at least one of the activities assayed with the exception of beta-glycosidase. The results suggest that in the industrialized area the diversity of yeasts is less in the traditional area. Likewise, the potentiality of the non-Saccharomyces yeasts as enzyme producers with industrial interest has been confirmed. This study shows the negative effect of the use of monocultures over the biodiversity of yeasts in wine-producing regions.

Yeast cell differentiation: Lessons from pathogenic and non-pathogenic yeasts.

PubMed

Palková, Zdena; Váchová, Libuše

2016-09-01

Yeasts, historically considered to be single-cell organisms, are able to activate different differentiation processes. Individual yeast cells can change their life-styles by processes of phenotypic switching such as the switch from yeast-shaped cells to filamentous cells (pseudohyphae or true hyphae) and the transition among opaque, white and gray cell-types. Yeasts can also create organized multicellular structures such as colonies and biofilms, and the latter are often observed as contaminants on surfaces in industry and medical care and are formed during infections of the human body. Multicellular structures are formed mostly of stationary-phase or slow-growing cells that diversify into specific cell subpopulations that have unique metabolic properties and can fulfill specific tasks. In addition to the development of multiple protective mechanisms, processes of metabolic reprogramming that reflect a changed environment help differentiated individual cells and/or community cell constituents to survive harmful environmental attacks and/or to escape the host immune system. This review aims to provide an overview of differentiation processes so far identified in individual yeast cells as well as in multicellular communities of yeast pathogens of the Candida and Cryptococcus spp. and the Candida albicans close relative, Saccharomyces cerevisiae. Molecular mechanisms and extracellular signals potentially involved in differentiation processes are also briefly mentioned. Copyright © 2016 Elsevier Ltd. All rights reserved.

L-arabinose fermenting yeast

DOEpatents

Zhang, Min; Singh, Arjun; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric; Suominen, Pirkko

2010-12-07

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##

Nitrile Metabolizing Yeasts

NASA Astrophysics Data System (ADS)

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

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

Highly enantioselective production of (R)-halohydrins with whole cells of Rhodotorula rubra KCh 82 culture.

PubMed

Janeczko, Tomasz; Dymarska, Monika; Kostrzewa-Susłow, Edyta

2014-12-04

Biotransformation of ten α-haloacetophenones in the growing culture of the strain Rhodotorula rubra KCh 82 has been carried out. Nine of the substrates underwent an effective enantioselective reduction to the respective (R)-alcohols according to Prelog's rule, with the exception of 2-chloro-1,2-diphenylethan-1-one that was not transformed by this strain. The expected reduction proceeded without dehalogenation, leading to the respective (R)-halohydrins in high yields. The use of this biocatalyst yielded (R)-2-bromo-1-phenyl-ethan-1-ol (enantiomeric excess (ee) = 97%) and its derivatives: 4'-Bromo- (ee = 99%); 4'-Chloro- (ee > 99%); 4'-Methoxy- (ee = 96%); 3'-Methoxy- (ee = 93%); 2'-Methoxy- (ee = 98%). There were also obtained and characterized 2,4'-dichloro-, 2,2',4'-trichloro- and 2-chloro-4'-fluoro-phenyetan-1-ol with >99% of enantiomeric excesses.

Highly Enantioselective Production of (R)-Halohydrins with Whole Cells of Rhodotorula rubra KCh 82 Culture

PubMed Central

Janeczko, Tomasz; Dymarska, Monika; Kostrzewa-Susłow, Edyta

2014-01-01

Biotransformation of ten α-haloacetophenones in the growing culture of the strain Rhodotorula rubra KCh 82 has been carried out. Nine of the substrates underwent an effective enantioselective reduction to the respective (R)-alcohols according to Prelog’s rule, with the exception of 2-chloro-1,2-diphenylethan-1-one that was not transformed by this strain. The expected reduction proceeded without dehalogenation, leading to the respective (R)-halohydrins in high yields. The use of this biocatalyst yielded (R)-2-bromo-1-phenyl-ethan-1-ol (enantiomeric excess (ee) = 97%) and its derivatives: 4'-Bromo- (ee = 99%); 4'-Chloro- (ee > 99%); 4'-Methoxy- (ee = 96%); 3'-Methoxy- (ee = 93%); 2'-Methoxy- (ee = 98%). There were also obtained and characterized 2,4'-dichloro-, 2,2',4'-trichloro- and 2-chloro-4'-fluoro-phenyetan-1-ol with >99% of enantiomeric excesses. PMID:25486054

Genome dynamics and evolution in yeasts: A long-term yeast-bacteria competition experiment

PubMed Central

Katz, Michael; Knecht, Wolfgang; Compagno, Concetta; Piškur, Jure

2018-01-01

There is an enormous genetic diversity evident in modern yeasts, but our understanding of the ecological basis of such diversifications in nature remains at best fragmented so far. Here we report a long-term experiment mimicking a primordial competitive environment, in which yeast and bacteria co-exist and compete against each other. Eighteen yeasts covering a wide phylogenetic background spanning approximately 250 million years of evolutionary history were used to establish independent evolution lines for at most 130 passages. Our collection of hundreds of modified strains generated through such a rare two-species cross-kingdom competition experiment re-created the appearance of large-scale genomic rearrangements and altered phenotypes important in the diversification history of yeasts. At the same time, the methodology employed in this evolutionary study would also be a non-gene-technological method of reprogramming yeast genomes and then selecting yeast strains with desired traits. Cross-kingdom competition may therefore be a method of significant value to generate industrially useful yeast strains with new metabolic traits. PMID:29624585

New yeasts-new brews: modern approaches to brewing yeast design and development.

PubMed

Gibson, B; Geertman, J-M A; Hittinger, C T; Krogerus, K; Libkind, D; Louis, E J; Magalhães, F; Sampaio, J P

2017-06-01

The brewing industry is experiencing a period of change and experimentation largely driven by customer demand for product diversity. This has coincided with a greater appreciation of the role of yeast in determining the character of beer and the widespread availability of powerful tools for yeast research. Genome analysis in particular has helped clarify the processes leading to domestication of brewing yeast and has identified domestication signatures that may be exploited for further yeast development. The functional properties of non-conventional yeast (both Saccharomyces and non-Saccharomyces) are being assessed with a view to creating beers with new flavours as well as producing flavoursome non-alcoholic beers. The discovery of the psychrotolerant S. eubayanus has stimulated research on de novo S. cerevisiae × S. eubayanus hybrids for low-temperature lager brewing and has led to renewed interest in the functional importance of hybrid organisms and the mechanisms that determine hybrid genome function and stability. The greater diversity of yeast that can be applied in brewing, along with an improved understanding of yeasts' evolutionary history and biology, is expected to have a significant and direct impact on the brewing industry, with potential for improved brewing efficiency, product diversity and, above all, customer satisfaction. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Yeasts from Scarlet ibises (Eudocimus ruber): A focus on monitoring the antifungal susceptibility of Candida famata and closely related species.

PubMed

Brilhante, Raimunda Sâmia Nogueira; Silva, Aline Lobão da; Monteiro, Frederico Ozanan Barros; Guedes, Glaucia Morgana de Melo; Sales, Jamille Alencar; Oliveira, Jonathas Sales de; Maia Junior, José Erisvaldo; Miranda, Stefânia Araújo; Sidrim, José Júlio Costa; Alencar, Lucas Pereira de; Castelo-Branco, Débora Souza Collares Maia; Cordeiro, Rossana de Aguiar; Pereira Neto, Waldemiro de Aquino; Rocha, Marcos Fábio Gadelha

2017-10-01

This study aimed to identify yeasts from the gastrointestinal tract of scarlet ibises (Eudocimus ruber) and from plant material collected from the environment where they live. Then, the isolates phenotypically identified as Candida famata were submitted to molecular identification of their closely related species and evaluated for their antifungal susceptibility and possible resistance mechanisms to antifungal drugs. Cloacal swabs from 20 scarlet ibises kept in captivity at Mangal das Garças Park (Brazil), pooled stool samples (n = 20) and samples of trunks and hollow of trees (n = 20) obtained from their enclosures were collected. The samples were seeded on Sabouraud agar supplemented with chloramphenicol. The 48 recovered isolates were phenotypically identified as 15 Candida famata, 13 Candida catenulata, 2 Candida intermedia, 1 Candida lusitaniae, 2 Candida guilliermondii, 1 Candida kefyr, 1 Candida amapae, 1 Candida krusei, 8 Trichosporon spp., and 4 Rhodotorula spp. The C. famata isolates were further identified as 3 C. famata, 8 Debaryomyces nepalensis, and 4 C. palmioleophila. All C. famata and C. palmioleophila were susceptible to caspofungin and itraconazole, while one D. nepalensis was resistant to fluconazole and voriconazole. This same isolate and another D. nepalensis had lower amphotericin B susceptibility. The azole resistant strain had an increased efflux of rhodamine 6G and an alteration in the membrane sterol content, demonstrating multifactorial resistance mechanism. Finally, this research shows that scarlet ibises and their environment harbor C. famata and closely related species, including antifungal resistant isolates, emphasizing the need of monitoring the antifungal susceptibility of these yeast species. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Vaginal yeast infection

MedlinePlus

Yeast infection - vagina; Vaginal candidiasis; Monilial vaginitis ... Most women have a vaginal yeast infection at some time. Candida albicans is a common type of fungus. It is often found in small amounts in the ...

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

PubMed

Niki, Hironori

2014-03-01

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. © 2013 The Author. Yeast Published by John Wiley & Sons Ltd.

Marine yeast isolation and industrial application.

PubMed

Zaky, Abdelrahman Saleh; Tucker, Gregory A; Daw, Zakaria Yehia; Du, Chenyu

2014-09-01

Over the last century, terrestrial yeasts have been widely used in various industries, such as baking, brewing, wine, bioethanol and pharmaceutical protein production. However, only little attention has been given to marine yeasts. Recent research showed that marine yeasts have several unique and promising features over the terrestrial yeasts, for example higher osmosis tolerance, higher special chemical productivity and production of industrial enzymes. These indicate that marine yeasts have great potential to be applied in various industries. This review gathers the most recent techniques used for marine yeast isolation as well as the latest applications of marine yeast in bioethanol, pharmaceutical and enzyme production fields. © 2014 The Authors FEMS Yeast Research published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

[Biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5].

PubMed

Hu, Rong; Huang, Jian-Bo; Yang, Zhou-Ping; Cheng, Zi-Zhang; Jing, De-Jun; Huang, Qian-Ming

2011-12-01

With a shaker, this paper studied the characteristics of the biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5 under different adsorption time, initial pH, and temperature, as well as the desorption and recycling use of the dyes. The biosorption of crystal violet and malachite green by R. graminis Y-5 had the peaks (93.8% and 87.7%, respectively) at pH 7.0, dye concentration 50 mg x L(-1), 150 r x min(-1), 30 degrees C, and lasting 10 hours. After desorption, the biosorption rate of crystal violet and malachite green by R. graminis was 85.5% and 78.5%, respectively, indicating that the biosorption of crystal violet and malachite green was reversible, and the recycling use of the dyes by R. graminis was quite good, i. e., the dyes were renewable and could be recycled. Biosorption could be the mechanism of the decolorization of the dyes. The dyes were mostly adsorbed on the R. graminis surface -OH. The adsorption process was fast, efficient, and reversible, suggesting that R. graminis had a high potential for waste water treatment.

Yeast ecology of Kombucha fermentation.

PubMed

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

2004-09-01

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.

Marine yeast isolation and industrial application

PubMed Central

Zaky, Abdelrahman Saleh; Tucker, Gregory A; Daw, Zakaria Yehia; Du, Chenyu

2014-01-01

Over the last century, terrestrial yeasts have been widely used in various industries, such as baking, brewing, wine, bioethanol and pharmaceutical protein production. However, only little attention has been given to marine yeasts. Recent research showed that marine yeasts have several unique and promising features over the terrestrial yeasts, for example higher osmosis tolerance, higher special chemical productivity and production of industrial enzymes. These indicate that marine yeasts have great potential to be applied in various industries. This review gathers the most recent techniques used for marine yeast isolation as well as the latest applications of marine yeast in bioethanol, pharmaceutical and enzyme production fields. PMID:24738708

Crystallization and preliminary X-ray analysis of the NADPH-dependent 3-quinuclidinone reductase from Rhodotorula rubra

PubMed Central

Takeshita, Daijiro; Kataoka, Michihiko; Miyakawa, Takuya; Miyazono, Ken-ichi; Uzura, Atsuko; Nagata, Koji; Shimizu, Sakayu; Tanokura, Masaru

2009-01-01

(R)-3-Quinuclidinol is a useful compound that is applicable to the synthesis of various pharmaceuticals. The NADPH-dependent carbonyl reductase 3-­quinuclidinone reductase from Rhodotorula rubra catalyzes the stereospecific reduction of 3-quinuclidinone to (R)-3-quinuclidinol and is expected to be utilized in industrial production of this alcohol. 3-Quinuclidinone reductase from R. rubra was expressed in Escherichia coli and purified using Ni-affinity and ion-exchange column chromatography. Crystals of the protein were obtained by the sitting-drop vapour-diffusion method using PEG 8000 as the precipitant. The crystals belonged to space group P41212, with unit-cell parameters a = b = 91.3, c = 265.4 Å, and diffracted X-rays to 2.2 Å resolution. The asymmetric unit contained four molecules of the protein and the solvent content was 48.4%. PMID:19478454

Wine yeasts for the future.

PubMed

Fleet, Graham H

2008-11-01

International competition within the wine market, consumer demands for newer styles of wines and increasing concerns about the environmental sustainability of wine production are providing new challenges for innovation in wine fermentation. Within the total production chain, the alcoholic fermentation of grape juice by yeasts is a key process where winemakers can creatively engineer wine character and value through better yeast management and, thereby, strategically tailor wines to a changing market. This review considers the importance of yeast ecology and yeast metabolic reactions in determining wine quality, and then discusses new directions for exploiting yeasts in wine fermentation. It covers criteria for selecting and developing new commercial strains, the possibilities of using yeasts other than those in the genus of Saccharomyces, the prospects for mixed culture fermentations and explores the possibilities for high cell density, continuous fermentations.

Discussion of teleomorphic and anamorphic Ascomycetous yeasts and yeast-like taxa

USDA-ARS?s Scientific Manuscript database

The relationship of ascomycetous yeasts with other members of the ascomycete fungi (Ascomycota) has been controversial for over 100 years. Because yeasts are morphologically simple, it was proposed that they represent primitive forms of ascomycetes (e.g., Guilliermond 1912). Alternatively, the ide...

Yeasts and yeast-like organisms associated with fruits and blossoms of different fruit trees.

PubMed

Vadkertiová, Renáta; Molnárová, Jana; Vránová, Dana; Sláviková, Elena

2012-12-01

Yeasts are common inhabitants of the phyllosphere, but our knowledge of their diversity in various plant organs is still limited. This study focused on the diversity of yeasts and yeast-like organisms associated with matured fruits and fully open blossoms of apple, plum, and pear trees, during 2 consecutive years at 3 localities in southwest Slovakia. The occurrence of yeasts and yeast-like organisms in fruit samples was 2½ times higher and the yeast community more diverse than that in blossom samples. Only 2 species (Aureobasidium pullulans and Metschnikowia pulcherrima) occurred regularly in the blossom samples, whereas Galactomyces candidus, Hanseniaspora guilliermondii, Hanseniaspora uvarum, M. pulcherrima, Pichia kluyveri, Pichia kudriavzevii, and Saccharomyces cerevisiae were the most frequently isolated species from the fruit samples. The ratio of the number of samples where only individual species were present to the number of samples where 2 or more species were found (consortium) was counted. The occurrence of individual species in comparison with consortia was much higher in blossom samples than in fruit samples. In the latter, consortia predominated. Aureobasidium pullulans, M. pulcherrima, and S. cerevisiae, isolated from both the fruits and blossoms, can be considered as resident yeast species of various fruit tree species cultivated in southwest Slovakia localities.

Forces in yeast flocculation

NASA Astrophysics Data System (ADS)

El-Kirat-Chatel, Sofiane; Beaussart, Audrey; Vincent, Stéphane P.; Abellán Flos, Marta; Hols, Pascal; Lipke, Peter N.; Dufrêne, Yves F.

2015-01-01

In the baker's yeast Saccharomyces cerevisiae, cell-cell adhesion (``flocculation'') is conferred by a family of lectin-like proteins known as the flocculin (Flo) proteins. Knowledge of the adhesive and mechanical properties of flocculins is important for understanding the mechanisms of yeast adhesion, and may help controlling yeast behaviour in biotechnology. We use single-molecule and single-cell atomic force microscopy (AFM) to explore the nanoscale forces engaged in yeast flocculation, focusing on the role of Flo1 as a prototype of flocculins. Using AFM tips labelled with mannose, we detect single flocculins on Flo1-expressing cells, showing they are widely exposed on the cell surface. When subjected to force, individual Flo1 proteins display two distinct force responses, i.e. weak lectin binding forces and strong unfolding forces reflecting the force-induced extension of hydrophobic tandem repeats. We demonstrate that cell-cell adhesion bonds also involve multiple weak lectin interactions together with strong unfolding forces, both associated with Flo1 molecules. Single-molecule and single-cell data correlate with microscale cell adhesion behaviour, suggesting strongly that Flo1 mechanics is critical for yeast flocculation. These results favour a model in which not only weak lectin-sugar interactions are involved in yeast flocculation but also strong hydrophobic interactions resulting from protein unfolding.

The yeast actin cytoskeleton.

PubMed

Mishra, Mithilesh; Huang, Junqi; Balasubramanian, Mohan K

2014-03-01

The actin cytoskeleton is a complex network of dynamic polymers, which plays an important role in various fundamental cellular processes, including maintenance of cell shape, polarity, cell division, cell migration, endocytosis, vesicular trafficking, and mechanosensation. Precise spatiotemporal assembly and disassembly of actin structures is regulated by the coordinated activity of about 100 highly conserved accessory proteins, which nucleate, elongate, cross-link, and sever actin filaments. Both in vivo studies in a wide range of organisms from yeast to metazoans and in vitro studies of purified proteins have helped shape the current understanding of actin dynamics and function. Molecular genetics, genome-wide functional analysis, sophisticated real-time imaging, and ultrastructural studies in concert with biochemical analysis have made yeast an attractive model to understand the actin cytoskeleton, its molecular dynamics, and physiological function. Studies of the yeast actin cytoskeleton have contributed substantially in defining the universal mechanism regulating actin assembly and disassembly in eukaryotes. Here, we review some of the important insights generated by the study of actin cytoskeleton in two important yeast models the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

[Thermoresistance in Saccharomyces cerevisiae yeasts].

PubMed

Kaliuzhin, V A

2011-01-01

Under natural conditions, yeast Saccharomyces cerevisiae reproduce, as a rule, on the surface of solid or liquid medium. Thus, life cycle of yeast populations is substantially influenced by diurnal changes in ambient temperature. The pattern in the response of unrestricted yeast S. cerevisiae culture to changes in the temperature of cultivation is revealed experimentally. Yeast population, in the absence of environmental constraints on the functioning of cell chemosmotic bioenergetic system, demonstrates the ability of thermoresistance when the temperature of cultivation switches from the range of 12-36 degrees C to 37.5-40 degrees C. During the transient period that is associated with the temperature switching and lasts from 1 to 4 turnover cycles, yeast reproduction rate remains 1.5-2 times higher than under stationary conditions. This is due to evolutionary acquired adaptive activity of cell chemosmotic system. After the adaptive resources exhausting, yeast thermoresistance fully recovers at the temperature range of 12-36 degrees C within one generation time under conditions of both restricted and unrestricted nourishment. Adaptive significance of such thermoresistance seems obvious enough--it allows maintaining high reproduction rate in yeast when ambient temperature is reaching a brief maximum shortly after noon.

Interaction Between Yeasts and Zinc

NASA Astrophysics Data System (ADS)

Nicola, Raffaele De; Walker, Graeme

Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

21 CFR 172.896 - Dried yeasts.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.896 Dried yeasts. Dried yeast (Saccharomyces cerevisiae and Saccharomyces fragilis) and dried torula yeast (Candida utilis...

Utilization of inulin-containing waste in industrial fermentations to produce biofuels and bio-based chemicals.

PubMed

Hughes, Stephen R; Qureshi, Nasib; López-Núñez, Juan Carlos; Jones, Marjorie A; Jarodsky, Joshua M; Galindo-Leva, Luz Ángela; Lindquist, Mitchell R

2017-04-01

Inulins are polysaccharides that belong to an important class of carbohydrates known as fructans and are used by many plants as a means of storing energy. Inulins contain 20 to several thousand fructose units joined by β-2,1 glycosidic bonds, typically with a terminal glucose unit. Plants with high concentrations of inulin include: agave, asparagus, coffee, chicory, dahlia, dandelion, garlic, globe artichoke, Jerusalem artichoke, jicama, onion, wild yam, and yacón. To utilize inulin as its carbon and energy source directly, a microorganism requires an extracellular inulinase to hydrolyze the glycosidic bonds to release fermentable monosaccharides. Inulinase is produced by many microorganisms, including species of Aspergillus, Kluyveromyces, Penicillium, and Pseudomonas. We review various inulinase-producing microorganisms and inulin feedstocks with potential for industrial application as well as biotechnological efforts underway to develop sustainable practices for the disposal of residues from processing inulin-containing crops. A multi-stage biorefinery concept is proposed to convert cellulosic and inulin-containing waste produced at crop processing operations to valuable biofuels and bioproducts using Kluyveromyces marxianus, Yarrowia lipolytica, Rhodotorula glutinis, and Saccharomyces cerevisiae as well as thermochemical treatments.

[Antimicrobial activity of volatile oil from Atractylodes lancea against three species of endophytic fungi and seven species of exogenous fungi].

PubMed

Wang, Yu; Dai, Chuan-Chao; Chen, Yan

2009-11-01

In order to investigate the inhibitory effects of host plants secondary metabolites on the growth of endophytic and exogenous fungi, the volatile oil from medicinal plant Atractylodes lancea was extracted with organic solvent extraction method, and its antimicrobial activity against three species of endophytic and seven species of exogenous fungi was determined by paper disc assay and spread-plate. The volatile oil had inhibitory effects on the growth of test endophytic fungi. It had strong antimicrobial activity against Rhodotorula glutinis and Saprolegnia, but weak activity against Rhizopus and Absidia. It suppressed the sporulation of Trichoderma viride and Aspergillus niger, but no effects on the growth of Phytophthora. Under the stress of high concentration volatile oil, the hyphal branches of test endophytic fungi increased, the distance between the branches became shorter, and the growth of aerial hyphae was inhibited. The test endophytic fungi had remarkable ability to metabolize and transform the volatile oil, and decreased the contents of its main ingredients. All the results showed that the volatile oil extracted from A. lancea had inhibitory effects on the growth of endophytic fungi, but the fungi could adapt to the volatile oil via metabolizing and decomposing it.

21 CFR 172.896 - Dried yeasts.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... 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 total folic acid...

21 CFR 172.896 - Dried yeasts.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... 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 total folic acid...

21 CFR 172.896 - Dried yeasts.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dried yeasts. 172.896 Section 172.896 Food and... 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 total folic acid...

21 CFR 172.896 - Dried yeasts.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Dried yeasts. 172.896 Section 172.896 Food and... 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 total folic acid...

Cultivation of oleaginous Rhodotorula mucilaginosa in airlift bioreactor by using seawater.

PubMed

Yen, Hong-Wei; Liao, Yu-Ting; Liu, Yi Xian

2016-02-01

The enormous water resource consumption is a concern to the scale-up fermentation process, especially for those cheap fermentation commodities, such as microbial oils as the feedstock for biodiesel production. The direct cultivation of oleaginous Rhodotorula mucilaginosa in a 5-L airlift bioreactor using seawater instead of pure water led to a slightly lower biomass being achieved, at 17.2 compared to 18.1 g/L, respectively. Nevertheless, a higher lipid content of 65 ± 5% was measured in the batch using seawater as compared to the pure water batch. Both the salinity and osmotic pressure decreased as the cultivation time increased in the seawater batch, and these effects may contribute to the high tolerance for salinity. No effects were observed for the seawater on the fatty acid profiles. The major components for both batches using seawater and pure water were C16:0 (palmitic acid), C18:1 (oleic acid) and C18:2 (linoleic acid), which together accounted for over 85% of total lipids. The results of this study indicated that seawater could be a suitable option for scaling up the growth of oleaginous R. mucilaginosa, especially from the perspective of water resource utilization. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Yeast flocculation: New story in fuel ethanol production.

PubMed

Zhao, X Q; Bai, F W

2009-01-01

Yeast flocculation has been used in the brewing industry to facilitate biomass recovery for a long time, and thus its mechanism of yeast flocculation has been intensively studied. However, the application of flocculating yeast in ethanol production garnered attention mainly in the 1980s and 1990s. In this article, updated research progress in the molecular mechanism of yeast flocculation and the impact of environmental conditions on yeast flocculation are reviewed. Construction of flocculating yeast strains by genetic approach and utilization of yeast flocculation for ethanol production from various feedstocks were presented. The concept of self-immobilized yeast cells through their flocculation is revisited through a case study of continuous ethanol fermentation with the flocculating yeast SPSC01, and their technical and economic advantages are highlighted by comparing with yeast cells immobilized with supporting materials and regular free yeast cells as well. Taking the flocculating yeast SPSC01 as an example, the ethanol tolerance of the flocculating yeast was also discussed.

Brewing characteristics of piezosensitive sake yeasts

NASA Astrophysics Data System (ADS)

Nomura, Kazuki; Hoshino, Hirofumi; Igoshi, Kazuaki; Onozuka, Haruka; Tanaka, Erika; Hayashi, Mayumi; Yamazaki, Harutake; Takaku, Hiroaki; Iguchi, Akinori; Shigematsu, Toru

2018-04-01

Application of high hydrostatic pressure (HHP) treatment to food processing is expected as a non-thermal fermentation regulation technology that supresses over fermentation. However, the yeast Saccharomyces cerevisiae used for Japanese rice wine (sake) brewing shows high tolerance to HHP. Therefore, we aimed to generate pressure-sensitive (piezosensitive) sake yeast strains by mating sake with piezosensitive yeast strains to establish an HHP fermentation regulation technology and extend the shelf life of fermented foods. The results of phenotypic analyses showed that the generated yeast strains were piezosensitive and exhibited similar fermentation ability compared with the original sake yeast strain. In addition, primary properties of sake brewed using these strains, such as ethanol concentration, sake meter value and sake flavor compounds, were almost equivalent to those obtained using the sake yeast strain. These results suggest that the piezosensitive strains exhibit brewing characteristics essentially equivalent to those of the sake yeast strain.

21 CFR 172.898 - Bakers yeast glycan.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Bakers yeast glycan. 172.898 Section 172.898 Food... Bakers yeast glycan. Bakers yeast glycan may be safely used in food in accordance with the following conditions: (a) Bakers yeast glycan is the comminuted, washed, pasteurized, and dried cell walls of the yeast...

Potential impact of Andrassy bentonite microbial diversity in the long-term performance of a deep nuclear waste repository

NASA Astrophysics Data System (ADS)

Tadza, M. Y. Mohd; Tadza, M. A. Mohd; Bag, R.; Harith, N. S. H.

2018-01-01

Copper and steel canning and bentonite buffer are normally forseen as the primary containment component of a deep nuclear waste repository. Distribution of microbes in subsurface environments have been found to be extensive and directly or indirectly may exert influence on waste canister corrosion and the mobility of radionuclides. The understanding of clays and microbial interaction with radionuclides will be useful in predicting the microbial impacts on the performance of the waste repositories. The present work characterizes the culture-dependent microbial diversity of Andrassy bentonite recovered from Tawau clay deposits. The evaluation of microbial populations shows the presence of a number of cultivable microbes (e.g. Staphylococcus, Micrococcus, Achromobacter, Bacillus, Paecilomyces, Trichoderma, and Fusarium). Additionally, a pigmented yeast strain Rhodotorula mucilaginosa was also recovered from the formation. Both Bacillus and Rhodotorula mucilaginosa have high tolerance towards U radiation and toxicity. The presence of Rhodotorula mucilaginosa in Andrassy bentonite might be able to change the speciation of radionuclides (e.g. uranium) in a future deep repository. However, concern over the presence of Fe (III) reduction microbes such as Bacillus also found in the formation could lead to corrosion of copper steel canister and affect the overall performance of the containment system.

Opportunistic Pathogenic Yeasts

NASA Astrophysics Data System (ADS)

Banerjee, Uma

Advances in medical research, made during the last few decades, have improved the prophylactic, diagnostic and therapeutic capabilities for variety of infections/diseases. However, many of the prophylactic and therapeutic procedures have been seen in many instances to exact a price of host-vulnerability to an expanding group of opportunistic pathogens and yeasts are one of the important members in it. Fortunately amongst the vast majority of yeasts present in nature only few are considered to have the capability to cause infections when certain opportunities predisposes and these are termed as ‘opportunistic pathogenic yeasts.’ However, the term ‘pathogenic’ is quite tricky, as it depends of various factors of the host, the ‘bug’ and the environment to manifest the clinical infection. The borderline is expanding. In the present century with unprecedented increase in number of immune-compromised host in various disciplines of health care settings, where any yeast, which has the capability to grow at 37 ° C (normal body temperature of human), can be pathogenic and cause infection in particular situation

Yeast Droplets

NASA Astrophysics Data System (ADS)

Nguyen, Baochi; Upadhyaya, Arpita; van Oudenaarden, Alexander; Brenner, Michael

2002-11-01

It is well known that the Young's law and surface tension govern the shape of liquid droplets on solid surfaces. Here we address through experiments and theory the shape of growing aggregates of yeast on agar substrates, and assess whether these ideas still hold. Experiments are carried out on Baker's yeast, with different levels of expressions of an adhesive protein governing cell-cell and cell-substrate adhesion. Changing either the agar concentration or the expression of this protein modifies the local contact angle of a yeast droplet. When the colony is small, the shape is a spherical cap with the contact angle obeying Young's law. However, above a critical volume this structure is unstable, and the droplet becomes nonspherical. We present a theoretical model where this instability is caused by bulk elastic effects. The model predicts that the transition depends on both volume and contact angle, in a manner quantitatively consistent with our experiments.

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

PubMed

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

2014-03-01

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. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Production of hydroxycinnamoyl anthranilates from glucose in Escherichia coli

PubMed Central

2013-01-01

Background Oats contain hydroxycinnamoyl anthranilates, also named avenanthramides (Avn), which have beneficial health properties because of their antioxidant, anti-inflammatory, and antiproliferative effects. The microbial production of hydroxycinnamoyl anthranilates is an eco-friendly alternative to chemical synthesis or purification from plant sources. We recently demonstrated in yeast (Saccharomyces cerevisiae) that coexpression of 4-coumarate: CoA ligase (4CL) from Arabidopsis thaliana and hydroxycinnamoyl/benzoyl-CoA/anthranilate N-hydroxycinnamoyl/benzoyltransferase (HCBT) from Dianthus caryophyllusenabled the biological production of several cinnamoyl anthranilates upon feeding with anthranilate and various cinnamates. Using engineering strategies to overproduce anthranilate and hydroxycinnamates, we describe here an entire pathway for the microbial synthesis of two Avns from glucose in Escherichia coli. Results We first showed that coexpression of HCBT and Nt4CL1 from tobacco in the E. coli anthranilate-accumulating strain W3110 trpD9923 allowed the production of Avn D [N-(4′-hydroxycinnamoyl)-anthranilic acid] and Avn F [N-(3′,4′-dihydroxycinnamoyl)-anthranilic acid] upon feeding with p-coumarate and caffeate, respectively. Moreover, additional expression in this strain of a tyrosine ammonia-lyase from Rhodotorula glutinis (RgTAL) led to the conversion of endogenous tyrosine into p-coumarate and resulted in the production of Avn D from glucose. Second, a 135-fold improvement in Avn D titer was achieved by boosting tyrosine production using two plasmids that express the eleven genes necessary for tyrosine synthesis from erythrose 4-phosphate and phosphoenolpyruvate. Finally, expression of either the p-coumarate 3-hydroxylase Sam5 from Saccharothrix espanensis or the hydroxylase complex HpaBC from E. coli resulted in the endogenous production of caffeate and biosynthesis of Avn F. Conclusion We established a biosynthetic pathway for the microbial

Lager Yeast Comes of Age

PubMed Central

2014-01-01

Alcoholic fermentations have accompanied human civilizations throughout our history. Lager yeasts have a several-century-long tradition of providing fresh beer with clean taste. The yeast strains used for lager beer fermentation have long been recognized as hybrids between two Saccharomyces species. We summarize the initial findings on this hybrid nature, the genomics/transcriptomics of lager yeasts, and established targets of strain improvements. Next-generation sequencing has provided fast access to yeast genomes. Its use in population genomics has uncovered many more hybridization events within Saccharomyces species, so that lager yeast hybrids are no longer the exception from the rule. These findings have led us to propose network evolution within Saccharomyces species. This “web of life” recognizes the ability of closely related species to exchange DNA and thus drain from a combined gene pool rather than be limited to a gene pool restricted by speciation. Within the domesticated lager yeasts, two groups, the Saaz and Frohberg groups, can be distinguished based on fermentation characteristics. Recent evidence suggests that these groups share an evolutionary history. We thus propose to refer to the Saaz group as Saccharomyces carlsbergensis and to the Frohberg group as Saccharomyces pastorianus based on their distinct genomes. New insight into the hybrid nature of lager yeast will provide novel directions for future strain improvement. PMID:25084862

Yeast killer systems.

PubMed Central

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

1997-01-01

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

Yeasts as distinct life forms of fungi

USDA-ARS?s Scientific Manuscript database

This review describes all presently recognized genera of the Ascomycete yeasts (Saccharomycotina, budding yeasts, and the Taphrinomycotina, fission yeasts and related) as well as all currently recognized genera of the Basidiomycete yeasts. This update will be the lead chapter for a book entitled “Ye...

Study of amyloids using yeast

PubMed Central

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

2012-01-01

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

Evolutionary History of Ascomyceteous Yeasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haridas, Sajeet; Riley, Robert; Salamov, Asaf

2014-06-06

Yeasts are important for many industrial and biotechnological processes and show remarkable diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. A comparison of these with several other previously published yeast genomes have added increased confidence to the phylogenetic positions of previously poorly placed species including Saitoella complicata, Babjeviella inositovora and Metschnikowia bicuspidata. Phylogenetic analysis also showed that yeasts with alternative nuclear codon usage where CUG encodes serine instead of leucine are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with amore » large fraction of single exon genes with Lipomyces starkeyi and the previously published Pneumocystis jirovecii being notable exceptions. Intron analysis suggests that early diverging species have more introns. We also observed a large number of unclassified lineage specific non-simple repeats in these genomes.« less

Eighteen new oleaginous yeast species.

PubMed

Garay, Luis A; Sitepu, Irnayuli R; Cajka, Tomas; Chandra, Idelia; Shi, Sandy; Lin, Ting; German, J Bruce; Fiehn, Oliver; Boundy-Mills, Kyria L

2016-07-01

Of 1600 known species of yeasts, about 70 are known to be oleaginous, defined as being able to accumulate over 20 % intracellular lipids. These yeasts have value for fundamental and applied research. A survey of yeasts from the Phaff Yeast Culture Collection, University of California Davis was performed to identify additional oleaginous species within the Basidiomycota phylum. Fifty-nine strains belonging to 34 species were grown in lipid inducing media, and total cell mass, lipid yield and triacylglycerol profiles were determined. Thirty-two species accumulated at least 20 % lipid and 25 species accumulated over 40 % lipid by dry weight. Eighteen of these species were not previously reported to be oleaginous. Triacylglycerol profiles were suitable for biodiesel production. These results greatly expand the number of known oleaginous yeast species, and reveal the wealth of natural diversity of triacylglycerol profiles within wild-type oleaginous Basidiomycetes.

Oral yeast colonization throughout pregnancy

PubMed Central

Rio, Rute; Simões-Silva, Liliana; Garro, Sofia; Silva, Mário-Jorge; Azevedo, Álvaro

2017-01-01

Background Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women. Material and Methods The oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collected, a non-invasive intra-oral examination was performed and saliva flow and pH were determined. Results Pregnant and non-pregnant groups were similar regarding age and level of education. Saliva flow rate did not differ, but saliva pH was lower in pregnant than in non-pregnant women. Oral yeast prevalence was higher in pregnant than in non-pregnant women, either in the first or in the third trimester, but did not attain statistical significance. In individuals colonized with yeast, the total yeast quantification (Log10CFU/mL) increase from the 1st to the 3rd trimester in pregnant women, but not in non-pregnant women. Conclusions Pregnancy may favour oral yeast growth that may be associated with an acidic oral environment. Key words:Oral yeast, fungi, pregnancy, saliva pH. PMID:28160578

Biomedical applications of yeast- a patent view, part one: yeasts as workhorses for the production of therapeutics and vaccines.

PubMed

Roohvand, Farzin; Shokri, Mehdi; Abdollahpour-Alitappeh, Meghdad; Ehsani, Parastoo

2017-08-01

Yeasts, as Eukaryotes, offer unique features for ease of growth and genetic manipulation possibilities, making it an exceptional microbial host. Areas covered: This review provides general and patent-oriented insights into production of biopharmaceuticals by yeasts. Patents, wherever possible, were correlated to the original or review articles. The review describes applications of major GRAS (generally regarded as safe) yeasts for the production of therapeutic proteins and subunit vaccines; additionally, immunomodulatory properties of yeast cell wall components were reviewed for use of whole yeast cells as a new vaccine platform. The second part of the review will discuss yeast- humanization strategies and innovative applications. Expert opinion: Biomedical applications of yeasts were initiated by utilization of Saccharomyces cerevisiae, for production of leavened (fermented) products, and advanced to serve to produce biopharmaceuticals. Higher biomass production and expression/secretion yields, more similarity of glycosylation patterns to mammals and possibility of host-improvement strategies through application of synthetic biology might enhance selection of Pichia pastoris (instead of S. cerevisiae) as a host for production of biopharmaceutical in future. Immunomodulatory properties of yeast cell wall β-glucans and possibility of intracellular expression of heterologous pathogen/tumor antigens in yeast cells have expanded their application as a new platform, 'Whole Yeast Vaccines'.

Nutrient supplements boost yeast transformation efficiency

PubMed Central

Yu, Sheng-Chun; Dawson, Alexander; Henderson, Alyssa C.; Lockyer, Eloise J.; Read, Emily; Sritharan, Gayathri; Ryan, Marjah; Sgroi, Mara; Ngou, Pok M.; Woodruff, Rosie; Zhang, Ruifeng; Ren Teen Chia, Travis; Liu, Yu; Xiang, Yiyu; Spanu, Pietro D.

2016-01-01

Efficiency of yeast transformation is determined by the rate of yeast endocytosis. The aim of this study was to investigate the effect of introducing amino acids and other nutrients (inositol, adenine, or p-aminobenzoic acid) in the transformation medium to develop a highly efficient yeast transformation protocol. The target of rapamycin complex 1 (TORC1) kinase signalling complex influences the rate of yeast endocytosis. TORC signaling is induced by amino acids in the media. Here, we found that increasing the concentration of amino acids and other nutrients in the growth media lead to an increase yeast transformation efficiency up to 107 CFU per μg plasmid DNA and per 108 cells with a 13.8 kb plasmid DNA. This is over 130 times that of current published methods. This improvement may facilitate more efficient experimentation in which transformation efficiency is critical, such as yeast two-hybrid screening. PMID:27760994

Virgin olive oil yeasts: A review.

PubMed

Ciafardini, Gino; Zullo, Biagi Angelo

2018-04-01

This review summarizes current knowledge on virgin olive oil yeasts. Newly produced olive oil contains solid particles and micro drops of vegetation water in which yeasts reproduce to become the typical microbiota of olive oil. To date, about seventeen yeast species have been isolated from different types of olive oils and their by-products, of which six species have been identified as new species. Certain yeast species contribute greatly to improving the sensorial characteristics of the newly produced olive oil, whereas other species are considered harmful as they can damage the oil quality through the production of unpleasant flavors and triacylglycerol hydrolysis. Studies carried out in certain yeast strains have demonstrated the presence of defects in olive oil treated with Candida adriatica, Nakazawaea wickerhamii and Candida diddensiae specific strains, while other olive oil samples treated with other Candida diddensiae strains were defect-free after four months of storage and categorized as extra virgin. A new acetic acid producing yeast species, namely, Brettanomyces acidodurans sp. nov., which was recently isolated from olive oil, could be implicated in the wine-vinegary defect of the product. Other aspects related to the activity of the lipase-producing yeasts and the survival of the yeast species in the flavored olive oils are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

21 CFR 184.1983 - Bakers yeast extract.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract is the food ingredient resulting from concentration of the solubles of mechanically ruptured cells of a selected strain of yeast, Saccharomyces...

21 CFR 184.1983 - Bakers yeast extract.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b) The...

21 CFR 184.1983 - Bakers yeast extract.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b) The...

History of genome editing in yeast.

PubMed

Fraczek, Marcin G; Naseeb, Samina; Delneri, Daniela

2018-05-01

For thousands of years humans have used the budding yeast Saccharomyces cerevisiae for the production of bread and alcohol; however, in the last 30-40 years our understanding of the yeast biology has dramatically increased, enabling us to modify its genome. Although S. cerevisiae has been the main focus of many research groups, other non-conventional yeasts have also been studied and exploited for biotechnological purposes. Our experiments and knowledge have evolved from recombination to high-throughput PCR-based transformations to highly accurate CRISPR methods in order to alter yeast traits for either research or industrial purposes. Since the release of the genome sequence of S. cerevisiae in 1996, the precise and targeted genome editing has increased significantly. In this 'Budding topic' we discuss the significant developments of genome editing in yeast, mainly focusing on Cre-loxP mediated recombination, delitto perfetto and CRISPR/Cas. © 2018 The Authors. Yeast published by John Wiley & Sons, Ltd.

Inventions on baker's yeast strains and specialty ingredients.

PubMed

Gélinas, Pierre

2009-06-01

Baker's yeast is one of the oldest food microbial starters. Between 1927 and 2008, 165 inventions on more than 337 baker's yeast strains were patented. The first generation of patented yeast strains claimed improved biomass yield at the yeast plant, higher gassing power in dough or better survival to drying to prepare active dry baker's yeast. Especially between 1980 and 1995, a major interest was given to strains for multiple bakery applications such as dough with variable sugar content and stored at refrigeration (cold) or freezing temperatures. During the same period, genetically engineered yeast strains became very popular but did not find applications in the baking industry. Since year 2000, patented baker's yeast strains claimed aroma, anti-moulding or nutritive properties to better meet the needs of the baking industry. In addition to patents on yeast strains, 47 patents were issued on baker's yeast specialty ingredients for niche markets. This review shows that patents on baker's yeast with improved characteristics such as aromatic or nutritive properties have regularly been issued since the 1920's. Overall, it also confirms recent interest for a very wide range of tailored-made yeast-based ingredients for bakery applications.

21 CFR 172.898 - Bakers yeast glycan.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Bakers yeast glycan. 172.898 Section 172.898 Food... Multipurpose Additives § 172.898 Bakers yeast glycan. Bakers yeast glycan may be safely used in food in accordance with the following conditions: (a) Bakers yeast glycan is the comminuted, washed, pasteurized, and...

21 CFR 172.898 - Bakers yeast glycan.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Bakers yeast glycan. 172.898 Section 172.898 Food... Multipurpose Additives § 172.898 Bakers yeast glycan. Bakers yeast glycan may be safely used in food in accordance with the following conditions: (a) Bakers yeast glycan is the comminuted, washed, pasteurized, and...

The wine and beer yeast Dekkera bruxellensis

PubMed Central

Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

2014-01-01

Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd. PMID:24932634

The wine and beer yeast Dekkera bruxellensis.

PubMed

Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

2014-09-01

Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd.

Biotechnology of non-Saccharomyces yeasts-the basidiomycetes.

PubMed

Johnson, Eric A

2013-09-01

Yeasts are the major producer of biotechnology products worldwide, exceeding production in capacity and economic revenues of other groups of industrial microorganisms. Yeasts have wide-ranging fundamental and industrial importance in scientific, food, medical, and agricultural disciplines (Fig. 1). Saccharomyces is the most important genus of yeast from fundamental and applied perspectives and has been expansively studied. Non-Saccharomyces yeasts (non-conventional yeasts) including members of the Ascomycetes and Basidiomycetes also have substantial current utility and potential applicability in biotechnology. In an earlier mini-review, "Biotechnology of non-Saccharomyces yeasts-the ascomycetes" (Johnson Appl Microb Biotechnol 97: 503-517, 2013), the extensive biotechnological utility and potential of ascomycetous yeasts are described. Ascomycetous yeasts are particularly important in food and ethanol formation, production of single-cell protein, feeds and fodder, heterologous production of proteins and enzymes, and as model and fundamental organisms for the delineation of genes and their function in mammalian and human metabolism and disease processes. In contrast, the roles of basidiomycetous yeasts in biotechnology have mainly been evaluated only in the past few decades and compared to the ascomycetous yeasts and currently have limited industrial utility. From a biotechnology perspective, the basidiomycetous yeasts are known mainly for the production of enzymes used in pharmaceutical and chemical synthesis, for production of certain classes of primary and secondary metabolites such as terpenoids and carotenoids, for aerobic catabolism of complex carbon sources, and for bioremediation of environmental pollutants and xenotoxicants. Notwithstanding, the basidiomycetous yeasts appear to have considerable potential in biotechnology owing to their catabolic utilities, formation of enzymes acting on recalcitrant substrates, and through the production of unique primary

Between science and industry-applied yeast research.

PubMed

Korhola, Matti

2018-03-01

I was fortunate to enter yeast research at the Alko Research Laboratories with a strong tradition in yeast biochemistry and physiology studies. At the same time in the 1980s there was a fundamental or paradigm change in molecular biology research with discoveries in DNA sequencing and other analytical and physical techniques for studying macromolecules and cells. Since that time biotechnological research has expanded the traditional fermentation industries to efficient production of industrial and other enzymes and specialty chemicals. Our efforts were directed towards improving the industrial production organisms: minerals enriched yeasts (Se, Cr, Zn) and high glutathione content yeast, baker´s, distiller´s, sour dough and wine yeasts, and the fungal Trichoderma reesei platform for enzyme production. I am grateful for the trust of my colleagues in several leadership positions at the Alko Research Laboratories, Yeast Industry Platform and at the international yeast community.

Yeast-based biosensors: design and applications.

PubMed

Adeniran, Adebola; Sherer, Michael; Tyo, Keith E J

2015-02-01

Yeast-based biosensing (YBB) is an exciting research area, as many studies have demonstrated the use of yeasts to accurately detect specific molecules. Biosensors incorporating various yeasts have been reported to detect an incredibly large range of molecules including but not limited to odorants, metals, intracellular metabolites, carcinogens, lactate, alcohols, and sugars. We review the detection strategies available for different types of analytes, as well as the wide range of output methods that have been incorporated with yeast biosensors. We group biosensors into two categories: those that are dependent upon transcription of a gene to report the detection of a desired molecule and those that are independent of this reporting mechanism. Transcription-dependent biosensors frequently depend on heterologous expression of sensing elements from non-yeast organisms, a strategy that has greatly expanded the range of molecules available for detection by YBBs. Transcription-independent biosensors circumvent the problem of sensing difficult-to-detect analytes by instead relying on yeast metabolism to generate easily detected molecules when the analyte is present. The use of yeast as the sensing element in biosensors has proven to be successful and continues to hold great promise for a variety of applications. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

Oral yeast colonization throughout pregnancy.

PubMed

Rio, R; Simões-Silva, L; Garro, S; Silva, M-J; Azevedo, Á; Sampaio-Maia, B

2017-03-01

Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women. The oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collected, a non-invasive intra-oral examination was performed and saliva flow and pH were determined. Pregnant and non-pregnant groups were similar regarding age and level of education. Saliva flow rate did not differ, but saliva pH was lower in pregnant than in non-pregnant women. Oral yeast prevalence was higher in pregnant than in non-pregnant women, either in the first or in the third trimester, but did not attain statistical significance. In individuals colonized with yeast, the total yeast quantification (Log10CFU/mL) increase from the 1st to the 3rd trimester in pregnant women, but not in non-pregnant women. Pregnancy may favour oral yeast growth that may be associated with an acidic oral environment.

Biotechnological Applications of Dimorphic Yeasts

NASA Astrophysics Data System (ADS)

Doiphode, N.; Joshi, C.; Ghormade, V.; Deshpande, M. V.

The dimorphic yeasts have the equilibrium between spherical growth (budding) and polarized (hyphal or pseudohyphal tip elongation) which can be triggered by change in the environmental conditions. The reversible growth phenomenon has made dimorphic yeasts as an useful model to understand fungal evolution and fungal differentiation, in general. In nature dimorphism is clearly evident in plant and animal fungal pathogens, which survive and most importantly proliferate in the respective hosts. However, number of organisms with no known pathogenic behaviour also show such a transition, which can be exploited for the technological applications due to their different biochemical make up under different morphologies. For instance, chitin and chitosan production using dimorphic Saccharomyces, Mucor, Rhizopus and Benjaminiella, oil degradation and biotransformation with yeast-form of Yarrowia species, bioremediation of organic pollutants, exopolysac-charide production by yeast-phase of Aureobasidium pullulans, to name a few. Myrothecium verrucaria can be used for seed dressing in its yeast form and it produces a mycolytic enzyme complex in its hyphal-form for the biocontrol of fungal pathogens, while Beauveria bassiana and other entomopathogens kill the insect pest by producing yeast- like cells in the insect body. The form-specific expression of protease, chitinase, lipase, ornithine decarboxylase, glutamate dehydrogenases, etc. make Benjaminiella poitrasii, Basidiobolus sp., and Mucor rouxii strains important in bioremediation, nanobiotechnology, fungal evolution and other areas.

Yeasts of the soil – obscure but precious

PubMed Central

2018-01-01

Abstract Pioneering studies performed in the nineteenth century demonstrated that yeasts are present in below‐ground sources. Soils were regarded more as a reservoir for yeasts that reside in habitats above it. Later studies showed that yeast communities in soils are taxonomically diverse and different from those above‐ground. Soil yeasts possess extraordinary adaptations that allow them to survive in a wide range of environmental conditions. A few species are promising sources of yeast oils and have been used in agriculture as potential antagonists of soil‐borne plant pathogens or as plant growth promoters. Yeasts have been studied mainly in managed soils such as vineyards, orchards and agricultural fields, and to a lesser extent under forests and grasslands. Our knowledge of soil yeasts is further biased towards temperate and boreal forests, whereas data from Africa, the Americas and Asia are scarce. Although soil yeast communities are often species‐poor in a single sample, they are more diverse on the biotope level. Soil yeasts display pronounced endemism along with a surprisingly high proportion of currently unidentified species. However, like other soil inhabitants, yeasts are threatened by habitat alterations owing to anthropogenic activities such as agriculture, deforestation and urbanization. In view of the rapid decline of many natural habitats, the study of soil yeasts in undisturbed or low‐managed biotopes is extremely valuable. The purpose of this review is to encourage researchers, both biologists and soil scientists, to include soil yeasts in future studies. PMID:29365211

Electron transport chain in a thermotolerant yeast.

PubMed

Mejía-Barajas, Jorge A; Martínez-Mora, José A; Salgado-Garciglia, Rafael; Noriega-Cisneros, Ruth; Ortiz-Avila, Omar; Cortés-Rojo, Christian; Saavedra-Molina, Alfredo

2017-04-01

Yeasts capable of growing and surviving at high temperatures are regarded as thermotolerant. For appropriate functioning of cellular processes and cell survival, the maintenance of an optimal redox state is critical of reducing and oxidizing species. We studied mitochondrial functions of the thermotolerant Kluyveromyces marxianus SLP1 and the mesophilic OFF1 yeasts, through the evaluation of its mitochondrial membrane potential (ΔΨ m ), ATPase activity, electron transport chain (ETC) activities, alternative oxidase activity, lipid peroxidation. Mitochondrial membrane potential and the cytoplasmic free Ca 2+ ions (Ca 2+ cyt) increased in the SLP1 yeast when exposed to high temperature, compared with the mesophilic yeast OFF1. ATPase activity in the mesophilic yeast diminished 80% when exposed to 40° while the thermotolerant SLP1 showed no change, despite an increase in the mitochondrial lipid peroxidation. The SLP1 thermotolerant yeast exposed to high temperature showed a diminution of 33% of the oxygen consumption in state 4. The uncoupled state 3 of oxygen consumption did not change in the mesophilic yeast when it had an increase of temperature, whereas in the thermotolerant SLP1 yeast resulted in an increase of 2.5 times when yeast were grown at 30 o , while a decrease of 51% was observed when it was exposed to high temperature. The activities of the ETC complexes were diminished in the SLP1 when exposed to high temperature, but also it was distinguished an alternative oxidase activity. Our results suggest that the mitochondria state, particularly ETC state, is an important characteristic of the thermotolerance of the SLP1 yeast strain.

Yeasts in floral nectar: a quantitative survey

PubMed Central

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

2009-01-01

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

Interactions between Drosophila and its natural yeast symbionts—Is Saccharomyces cerevisiae a good model for studying the fly-yeast relationship?

PubMed Central

Hoang, Don; Kopp, Artyom

2015-01-01

Yeasts play an important role in the biology of the fruit fly, Drosophila melanogaster. In addition to being a valuable source of nutrition, yeasts affect D. melanogaster behavior and interact with the host immune system. Most experiments investigating the role of yeasts in D. melanogaster biology use the baker’s yeast, Saccharomyces cerevisiae. However, S. cerevisiae is rarely found with natural populations of D. melanogaster or other Drosophila species. Moreover, the strain of S. cerevisiae used most often in D. melanogaster experiments is a commercially and industrially important strain that, to the best of our knowledge, was not isolated from flies. Since disrupting natural host–microbe interactions can have profound effects on host biology, the results from D. melanogaster–S. cerevisiae laboratory experiments may not be fully representative of host–microbe interactions in nature. In this study, we explore the D. melanogaster-yeast relationship using five different strains of yeast that were isolated from wild Drosophila populations. Ingested live yeasts have variable persistence in the D. melanogaster gastrointestinal tract. For example, Hanseniaspora occidentalis persists relative to S. cerevisiae, while Brettanomyces naardenensis is removed. Despite these differences in persistence relative to S. cerevisiae, we find that all yeasts decrease in total abundance over time. Reactive oxygen species (ROS) are an important component of the D. melanogaster anti-microbial response and can inhibit S. cerevisiae growth in the intestine. To determine if sensitivity to ROS explains the differences in yeast persistence, we measured yeast growth in the presence and absence of hydrogen peroxide. We find that B. naardenesis is completely inhibited by hydrogen peroxide, while H. occidentalis is not, which is consistent with yeast sensitivity to ROS affecting persistence within the D. melanogaster gastrointestinal tract. We also compared the feeding preference of D

Interactions between Drosophila and its natural yeast symbionts-Is Saccharomyces cerevisiae a good model for studying the fly-yeast relationship?

PubMed

Hoang, Don; Kopp, Artyom; Chandler, James Angus

2015-01-01

Yeasts play an important role in the biology of the fruit fly, Drosophila melanogaster. In addition to being a valuable source of nutrition, yeasts affect D. melanogaster behavior and interact with the host immune system. Most experiments investigating the role of yeasts in D. melanogaster biology use the baker's yeast, Saccharomyces cerevisiae. However, S. cerevisiae is rarely found with natural populations of D. melanogaster or other Drosophila species. Moreover, the strain of S. cerevisiae used most often in D. melanogaster experiments is a commercially and industrially important strain that, to the best of our knowledge, was not isolated from flies. Since disrupting natural host-microbe interactions can have profound effects on host biology, the results from D. melanogaster-S. cerevisiae laboratory experiments may not be fully representative of host-microbe interactions in nature. In this study, we explore the D. melanogaster-yeast relationship using five different strains of yeast that were isolated from wild Drosophila populations. Ingested live yeasts have variable persistence in the D. melanogaster gastrointestinal tract. For example, Hanseniaspora occidentalis persists relative to S. cerevisiae, while Brettanomyces naardenensis is removed. Despite these differences in persistence relative to S. cerevisiae, we find that all yeasts decrease in total abundance over time. Reactive oxygen species (ROS) are an important component of the D. melanogaster anti-microbial response and can inhibit S. cerevisiae growth in the intestine. To determine if sensitivity to ROS explains the differences in yeast persistence, we measured yeast growth in the presence and absence of hydrogen peroxide. We find that B. naardenesis is completely inhibited by hydrogen peroxide, while H. occidentalis is not, which is consistent with yeast sensitivity to ROS affecting persistence within the D. melanogaster gastrointestinal tract. We also compared the feeding preference of D

Evaluation of Automated Yeast Identification System

NASA Technical Reports Server (NTRS)

McGinnis, M. R.

1996-01-01

One hundred and nine teleomorphic and anamorphic yeast isolates representing approximately 30 taxa were used to evaluate the accuracy of the Biolog yeast identification system. Isolates derived from nomenclatural types, environmental, and clinica isolates of known identity were tested in the Biolog system. Of the isolates tested, 81 were in the Biolog database. The system correctly identified 40, incorrectly identified 29, and was unable to identify 12. Of the 28 isolates not in the database, 18 were given names, whereas 10 were not. The Biolog yeast identification system is inadequate for the identification of yeasts originating from the environment during space program activities.

Genomics and the making of yeast biodiversity.

PubMed

Hittinger, Chris Todd; Rokas, Antonis; Bai, Feng-Yan; Boekhout, Teun; Gonçalves, Paula; Jeffries, Thomas W; Kominek, Jacek; Lachance, Marc-André; Libkind, Diego; Rosa, Carlos A; Sampaio, José Paulo; Kurtzman, Cletus P

2015-12-01

Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces cerevisiae; the common human commensal and opportunistic pathogen, Candida albicans; and over 1000 other known species (with more continuing to be discovered). Yeasts are found in every biome and continent and are more genetically diverse than angiosperms or chordates. Ease of culture, simple life cycles, and small genomes (∼10-20Mbp) have made yeasts exceptional models for molecular genetics, biotechnology, and evolutionary genomics. Here we discuss recent developments in understanding the genomic underpinnings of the making of yeast biodiversity, comparing and contrasting natural and human-associated evolutionary processes. Only a tiny fraction of yeast biodiversity and metabolic capabilities has been tapped by industry and science. Expanding the taxonomic breadth of deep genomic investigations will further illuminate how genome function evolves to encode their diverse metabolisms and ecologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Accelerating Yeast Prion Biology using Droplet Microfluidics

NASA Astrophysics Data System (ADS)

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

2012-02-01

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.

Genomics and the making of yeast biodiversity

USDA-ARS?s Scientific Manuscript database

Yeasts are unicellular fungi that do not form fruiting bodies. Although the yeast lifestyle has evolved multiple times, most known species belong to the subphylum Saccharomycotina (syn. Hemiascomycota, hereafter yeasts). This diverse group includes the premier eukaryotic model system, Saccharomyces ...

21 CFR 172.590 - Yeast-malt sprout extract.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout extract, as described in this section, may... produced by partial hydrolysis of yeast extract (derived from Saccharomyces cereviseae, Saccharomyces...

Yeasts Diversity in Fermented Foods and Beverages

NASA Astrophysics Data System (ADS)

Tamang, Jyoti Prakash; Fleet, Graham H.

People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

Genetics of Yeasts

NASA Astrophysics Data System (ADS)

Querol, Amparo; Fernández-Espinar, M. Teresa; Belloch, Carmela

The use of yeasts in biotechnology processes dates back to ancient days. Before 7000 BC, beer was produced in Sumeria. Wine was made in Assyria in 3500 BC, and ancient Rome had over 250 bakeries, which were making leavened bread by 100 BC. And milk has been made into Kefyr and Koumiss in Asia for many centuries (Demain, Phaff, & Kurtzman, 1999). However, the importance of yeast in the food and beverage industries was only realized about 1860, when their role in food manufacturing became evident.

21 CFR 172.590 - Yeast-malt sprout extract.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

21 CFR 172.590 - Yeast-malt sprout extract.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

21 CFR 172.590 - Yeast-malt sprout extract.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

21 CFR 172.590 - Yeast-malt sprout extract.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

Yeasts in sustainable bioethanol production: A review.

PubMed

Mohd Azhar, Siti Hajar; Abdulla, Rahmath; Jambo, Siti Azmah; Marbawi, Hartinie; Gansau, Jualang Azlan; Mohd Faik, Ainol Azifa; Rodrigues, Kenneth Francis

2017-07-01

Bioethanol has been identified as the mostly used biofuel worldwide since it significantly contributes to the reduction of crude oil consumption and environmental pollution. It can be produced from various types of feedstocks such as sucrose, starch, lignocellulosic and algal biomass through fermentation process by microorganisms. Compared to other types of microoganisms, yeasts especially Saccharomyces cerevisiae is the common microbes employed in ethanol production due to its high ethanol productivity, high ethanol tolerance and ability of fermenting wide range of sugars. However, there are some challenges in yeast fermentation which inhibit ethanol production such as high temperature, high ethanol concentration and the ability to ferment pentose sugars. Various types of yeast strains have been used in fermentation for ethanol production including hybrid, recombinant and wild-type yeasts. Yeasts can directly ferment simple sugars into ethanol while other type of feedstocks must be converted to fermentable sugars before it can be fermented to ethanol. The common processes involves in ethanol production are pretreatment, hydrolysis and fermentation. Production of bioethanol during fermentation depends on several factors such as temperature, sugar concentration, pH, fermentation time, agitation rate, and inoculum size. The efficiency and productivity of ethanol can be enhanced by immobilizing the yeast cells. This review highlights the different types of yeast strains, fermentation process, factors affecting bioethanol production and immobilization of yeasts for better bioethanol production.

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

NASA Astrophysics Data System (ADS)

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

1993-09-01

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.

Effects of different culture media on biodegradation of triclosan by Rhodotorula mucilaginosa and Penicillium sp.

PubMed

Ertit Taştan, Burcu; Özdemir, Caner; Tekinay, Turgay

Triclosan is an antimicrobial agent and a persistent pollutant. The biodegradation of triclosan is dependent on many variables including the biodegradation organism and the environmental conditions. Here, we evaluated the triclosan degradation potential of two fungi strains, Rhodotorula mucilaginosa and Penicillium sp., and the rate of its turnover to 2,4-dichlorophenol (2,4-DCP). Both of these strains showed less susceptibility to triclosan when grown in minimal salt medium. In order to further evaluate the effects of environmental conditions on triclosan degradation, three different culture conditions including original thermal power plant wastewater, T6 nutrimedia and ammonium mineral salts medium were used. The maximum triclosan degradation yield was 48% for R. mucilaginosa and 82% for Penicillium sp. at 2.7 mg/L triclosan concentration. Biodegradation experiments revealed that Penicillium sp. was more tolerant to triclosan. Scanning electron microscopy micrographs also showed the morphological changes of fungus when cells were treated with triclosan. Overall, these fungi strains could be used as effective microorganisms in active uptake (degradation) and passive uptake (sorption) of triclosan and their efficiency can be increased by optimizing the culture conditions.

Experimental Systems to Study Yeast Pexophagy.

PubMed

Yamashita, Shun-Ichi; Oku, Masahide; Sakai, Yasuyoshi; Fujiki, Yukio

2017-01-01

Peroxisome abundance is tightly regulated according to the physiological contexts, through regulations of both proliferation and degradation of the organelles. Here, we describe detailed methods to analyze processes for autophagic degradation of peroxisomes, termed pexophagy, in yeast organisms. The assay systems include a method for biochemical detection of pexophagy completion, and one for microscopic visualization of specialized membrane structures acting in pexophagy. As a model yeast organism utilized in studies of pexophagy, the methylotrophic yeast Komagataella phaffii (Pichia pastoris) is referred to in this chapter and related information on the studies with baker's yeast (Saccharomyces cerevisiae) is also included. The described techniques facilitate elucidation of molecular machineries for pexophagy and understanding of peroxisome-selective autophagic pathways.

[Distiller Yeasts Producing Antibacterial Peptides].

PubMed

Klyachko, E V; Morozkina, E V; Zaitchik, B Ts; Benevolensky, S V

2015-01-01

A new method of controlling lactic acid bacteria contamination was developed with the use of recombinant Saccharomyces cerevisiae strains producing antibacterial peptides. Genes encoding the antibacterial peptides pediocin and plantaricin with codons preferable for S. cerevisiae were synthesized, and a system was constructed for their secretory expression. Recombinant S. cerevisiae strains producing antibacterial peptides effectively inhibit the growth of Lactobacillus sakei, Pediacoccus pentasaceus, Pediacoccus acidilactici, etc. The application of distiller yeasts producing antibacterial peptides enhances the ethanol yield in cases of bacterial contamination. Recombinant yeasts producing the antibacterial peptides pediocin and plantaricin can successfully substitute the available industrial yeast strains upon ethanol production.

Differential Adsorption of Ochratoxin A and Anthocyanins by Inactivated Yeasts and Yeast Cell Walls during Simulation of Wine Aging

PubMed Central

Petruzzi, Leonardo; Baiano, Antonietta; De Gianni, Antonio; Sinigaglia, Milena; Corbo, Maria Rosaria; Bevilacqua, Antonio

2015-01-01

The adsorption of ochratoxin A (OTA) by yeasts is a promising approach for the decontamination of musts and wines, but some potential competitive or interactive phenomena between mycotoxin, yeast cells, and anthocyanins might modify the intensity of the phenomenon. The aim of this study was to examine OTA adsorption by two strains of Saccharomyces cerevisiae (the wild strain W13, and the commercial isolate BM45), previously inactivated by heat, and a yeast cell wall preparation. Experiments were conducted using Nero di Troia red wine contaminated with 2 μg/L OTA and supplemented with yeast biomass (20 g/L). The samples were analyzed periodically to assess mycotoxin concentration, chromatic characteristics, and total anthocyanins over 84 days of aging. Yeast cell walls revealed the highest OTA-adsorption in comparison to thermally-inactivated cells (50% vs. 43% toxin reduction), whilst no significant differences were found for the amount of adsorbed anthocyanins in OTA-contaminated and control wines. OTA and anthocyanins adsorption were not competitive phenomena. Unfortunately, the addition of yeast cells to wine could cause color loss; therefore, yeast selection should also focus on this trait to select the best strain. PMID:26516913

Made for Each Other: Ascomycete Yeasts and Insects.

PubMed

Blackwell, Meredith

2017-06-01

Fungi and insects live together in the same habitats, and many species of both groups rely on each other for success. Insects, the most successful animals on Earth, cannot produce sterols, essential vitamins, and many enzymes; fungi, often yeast-like in growth form, make up for these deficits. Fungi, however, require constantly replenished substrates because they consume the previous ones, and insects, sometimes lured by volatile fungal compounds, carry fungi directly to a similar, but fresh, habitat. Yeasts associated with insects include Ascomycota (Saccharomycotina, Pezizomycotina) and a few Basidiomycota. Beetles, homopterans, and flies are important associates of fungi, and in turn the insects carry yeasts in pits, specialized external pouches, and modified gut pockets. Some yeasts undergo sexual reproduction within the insect gut, where the genetic diversity of the population is increased, while others, well suited to their stable environment, may never mate. The range of interactions extends from dispersal of yeasts on the surface of insects (e.g., cactus- Drosophila -yeast and ephemeral flower communities, ambrosia beetles, yeasts with holdfasts) to extremely specialized associations of organisms that can no longer exist independently, as in the case of yeast-like symbionts of planthoppers. In a few cases yeast-like fungus-insect associations threaten butterflies and other species with extinction. Technical advances improve discovery and identification of the fungi but also inform our understanding of the evolution of yeast-insect symbioses, although there is much more to learn.

The growth of solar radiated yeast

NASA Technical Reports Server (NTRS)

Kraft, Tyrone

1995-01-01

This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containers with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.

The growth of solar radiated yeast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kraft, T.

This researcher plans to determine if solar radiation affects the growth of yeast. The irradiated yeast was obtained from a sample exposed in space during a Space Shuttle flight of September 9-20, 1994. Further, the control groups were held at: (1) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland; and (2) South Dakota School of Mines and Technology. The procedure used was based on the fact that yeast is most often used in consumable baked goods. Therefore, the yeast was incorporated into a basic Betty Crocker bread recipe. Data was collected by placing measured amounts of dough into sample containersmore » with fifteen minute growth in height measurements collected and recorded. This researcher assumed the viability of yeast to be relative to its ability to produce carbon dioxide gas and cause the dough to rise. As all ingredients and surroundings were equal, this researcher assumed the yeast will produce the only significant difference in data collected. This researcher noted the approximate use date on all sample packages to be prior to arrival and experiment date. All dates equal, it was then assumed each would act in a similar manner of response. This assumption will allow for equally correct data collection.« less

Freeze-drying of yeast cultures.

PubMed

Bond, Chris

2007-01-01

A method is described that allows yeast species to be stored using a variation on the standard freeze-drying method, which employs evaporative cooling in a two-stage process. Yeast cultures are placed in glass ampoules after having been mixed with a lyoprotectant. Primary drying is carried out using a centrifuge head connected to a standard freeze-dryer. Once the centrifuge head is running, air is removed and evaporated liquid is captured in the freeze-dryer. Centrifugation continues for 15 min and primary drying for a further 3 h. The ampoules are constricted using a glass blowing torch. They are then placed on the freeze-dryer manifold for secondary drying under vacuum overnight, using phosphorus pentoxide as a desiccant. The ampoules are sealed and removed from the manifold by melting the constricted section. Although the process causes an initial large drop in viability, further losses after storage are minimal. Yeast strains have remained viable for more than 30 yr when stored using this method and sufficient cells are recovered to produce new working stocks. Although survival rates are strain specific, nearly all National Collection of Yeast Cultures strains covering most yeast genera, have been successfully stored with little or no detectable change in strain characteristics.

Biotechnology of non-Saccharomyces yeasts--the ascomycetes.

PubMed

Johnson, Eric A

2013-01-01

Saccharomyces cerevisiae and several other yeast species are among the most important groups of biotechnological organisms. S. cerevisiae and closely related ascomycetous yeasts are the major producer of biotechnology products worldwide, exceeding other groups of industrial microorganisms in productivity and economic revenues. Traditional industrial attributes of the S. cerevisiae group include their primary roles in food fermentations such as beers, cider, wines, sake, distilled spirits, bakery products, cheese, sausages, and other fermented foods. Other long-standing industrial processes involving S. cerevisae yeasts are production of fuel ethanol, single-cell protein (SCP), feeds and fodder, industrial enzymes, and small molecular weight metabolites. More recently, non-Saccharomyces yeasts (non-conventional yeasts) have been utilized as industrial organisms for a variety of biotechnological roles. Non-Saccharomyces yeasts are increasingly being used as hosts for expression of proteins, biocatalysts and multi-enzyme pathways for the synthesis of fine chemicals and small molecular weight compounds of medicinal and nutritional importance. Non-Saccharomyces yeasts also have important roles in agriculture as agents of biocontrol, bioremediation, and as indicators of environmental quality. Several of these products and processes have reached commercial utility, while others are in advanced development. The objective of this mini-review is to describe processes currently used by industry and those in developmental stages and close to commercialization primarily from non-Saccharomyces yeasts with an emphasis on new opportunities. The utility of S. cerevisiae in heterologous production of selected products is also described.

Yeast proteome map (last update).

PubMed

Perrot, Michel; Moes, Suzette; Massoni, Aurélie; Jenoe, Paul; Boucherie, Hélian

2009-10-01

The identification of proteins separated on 2-D gels is essential to exploit the full potential of 2-D gel electrophoresis for proteomic investigations. For this purpose we have undertaken the systematic identification of Saccharomyces cerevisiae proteins separated on 2-D gels. We report here the identification by mass spectrometry of 100 novel yeast protein spots that have so far not been tackled due to their scarcity on our standard 2-D gels. These identifications extend the number of protein spots identified on our yeast 2-D proteome map to 716. They correspond to 485 unique proteins. Among these, 154 were resolved into several isoforms. The present data set can now be expanded to report for the first time a map of 363 protein isoforms that significantly deepens our knowledge of the yeast proteome. The reference map and a list of all identified proteins can be accessed on the Yeast Protein Map server (www.ibgc.u-bordeaux2.fr/YPM).

Clinical and mycological analysis of dog’s oral cavity

PubMed Central

Santin, Rosema; Mattei, Antonella Souza; Waller, Stefanie Bressan; Madrid, Isabel Martins; Cleff, Marlete Brum; Xavier, Melissa Orzechowski; de Oliveira Nobre, Márcia; Nascente, Patrícia da Silva; de Mello, João Roberto Braga; Meireles, Mário Carlos Araújo

2013-01-01

The oral microbiota of humans and animals is made up of a wide variety of yeasts and bacteria, but microbiota of dogs is not totally described. Although such identification is an important step to establish the etiopathogenesis and adequate therapy for the periodontal disease The aim of this study was to evaluate and correlate oral alterations with the presence of yeasts in oral cavity of female dogs. After clinical evaluation samples from healthy and from dogs with oral diseases were obtained from three different oral sites by swabs, curettes, millimeter periodontal probes and HA membrane tip in cellulose ester. Yeast identification was performed through macroscopic and microscopic colony features and biochemical tests. Dental calculus was the most prevalent occurrence in the oral cavity of 59 females. However, the isolation of yeasts was significantly higher (p < 0.05) in animals suffering from halitosis. Eleven yeast species were identified, namely: Malassezia pachydermatis, Rhodotorula spp., Candida albicans, C. catenulata, C. famata, C. guilliermondii, C. parapsilosis, C. intermedia, Trichosporon asahii, T. mucoides and Cryptococcus albidus. It could be concluded that the yeasts are part of the microbiota from the different sites of the oral cavity of the female canines studied without causing any significant alterations except halitosis. PMID:24159296

Septin Organization and Functions in Budding Yeast

PubMed Central

Glomb, Oliver; Gronemeyer, Thomas

2016-01-01

The septins are a conserved family of GTP-binding proteins present in all eukaryotic cells except plants. They were originally discovered in the baker's yeast Saccharomyces cerevisiae that serves until today as an important model organism for septin research. In yeast, the septins assemble into a highly ordered array of filaments at the mother bud neck. The septins are regulators of spatial compartmentalization in yeast and act as key players in cytokinesis. This minireview summarizes the recent findings about structural features and cell biology of the yeast septins. PMID:27857941

Taming wild yeast: potential of conventional and nonconventional yeasts in industrial fermentations.

PubMed

Steensels, Jan; Verstrepen, Kevin J

2014-01-01

Yeasts are the main driving force behind several industrial food fermentation processes, including the production of beer, wine, sake, bread, and chocolate. Historically, these processes developed from uncontrolled, spontaneous fermentation reactions that rely on a complex mixture of microbes present in the environment. Because such spontaneous processes are generally inconsistent and inefficient and often lead to the formation of off-flavors, most of today's industrial production utilizes defined starter cultures, often consisting of a specific domesticated strain of Saccharomyces cerevisiae, S. bayanus, or S. pastorianus. Although this practice greatly improved process consistency, efficiency, and overall quality, it also limited the sensorial complexity of the end product. In this review, we discuss how Saccharomyces yeasts were domesticated to become the main workhorse of food fermentations, and we investigate the potential and selection of nonconventional yeasts that are often found in spontaneous fermentations, such as Brettanomyces, Hanseniaspora, and Pichia spp.

Yeast: A Research Organism for Teaching Genetics.

ERIC Educational Resources Information Center

Manney, Thomas R.; Manney, Monta L.

1992-01-01

Explains why laboratory strains of bakers yeast, Saccharomyces cerevisiae, are particularly suited for classroom science activities. Describes the sexual life cycle of yeast and the genetic system with visible mutations. Presents an overview of activities that can be done with yeast and gives a source for teachers to obtain more information. (PR)

Introducing a new breed of wine yeast: interspecific hybridisation between a commercial Saccharomyces cerevisiae wine yeast and Saccharomyces mikatae.

PubMed

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

2013-01-01

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.

Yeast fuel cell: Application for desalination

NASA Astrophysics Data System (ADS)

Mardiana, Ummy; Innocent, Christophe; Cretin, Marc; Buchari, Buchari; Gandasasmita, Suryo

2016-02-01

Yeasts have been implicated in microbial fuel cells as biocatalysts because they are non-pathogenic organisms, easily handled and robust with a good tolerance in different environmental conditions. Here we investigated baker's yeast Saccharomyces cerevisiae through the oxidation of glucose. Yeast was used in the anolyte, to transfer electrons to the anode in the presence of methylene blue as mediator whereas K3Fe(CN)6 was used as an electron acceptor for the reduction reaction in the catholyte. Power production with biofuel cell was coupled with a desalination process. The maximum current density produced by the cell was 88 mA.m-2. In those conditions, it was found that concentration of salt was removed 64% from initial 0.6 M after 1-month operation. This result proves that yeast fuel cells can be used to remove salt through electrically driven membrane processes and demonstrated that could be applied for energy production and desalination. Further developments are in progress to improve power output to make yeast fuel cells applicable for water treatment.

Yeasts for Global Happiness: report of the 14th International Congress on Yeasts (ICY14) held in Awaji Island.

PubMed

Watanabe, Daisuke; Takagi, Hiroshi

2017-02-01

The 14th International Congress on Yeasts (ICY14) was held at Awaji Yumebutai International Conference Center (Awaji, Hyogo) in Japan from 11 to 15 September 2016. The main slogan of ICY14 was 'Yeasts for Global Happiness', which enabled us to acknowledge the high-potential usefulness of yeasts contributing to the global happiness in terms of food/beverage, health/medicine and energy/environment industries, as well as to basic biosciences. In addition, two more concepts were introduced: 'from Japan to the world' and 'from senior to junior'. As it was the first ICY meeting held in Japan or other Asian countries, ICY14 provided a good opportunity to widely spread the great achievements by Japanese and Asian yeast researchers, such as those by the 2016 Nobel Laureate Dr. Yoshinori Ohsumi, and also, to convey the fun and importance of yeasts to the next generation of researchers from Asia and all over the world. As a result, a total of 426 yeast lovers from 42 countries (225 overseas and 201 domestic participants) with different generations attended ICY14 to share the latest knowledge of a wide range of yeast research fields and to join active and constructive scientific discussions. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Volatilization and precipitation of tellurium by aerobic, tellurite-resistant marine microbes.

PubMed

Ollivier, Patrick R L; Bahrou, Andrew S; Marcus, Sarah; Cox, Talisha; Church, Thomas M; Hanson, Thomas E

2008-12-01

Microbial resistance to tellurite, an oxyanion of tellurium, is widespread in the biosphere, but the geochemical significance of this trait is poorly understood. As some tellurite resistance markers appear to mediate the formation of volatile tellurides, the potential contribution of tellurite-resistant microbial strains to trace element volatilization in salt marsh sediments was evaluated. Microbial strains were isolated aerobically on the basis of tellurite resistance and subsequently examined for their capacity to volatilize tellurium in pure cultures. The tellurite-resistant strains recovered were either yeasts related to marine isolates of Rhodotorula spp. or gram-positive bacteria related to marine strains within the family Bacillaceae based on rRNA gene sequence comparisons. Most strains produced volatile tellurides, primarily dimethyltelluride, though there was a wide range of the types and amounts of species produced. For example, the Rhodotorula spp. produced the greatest quantities and highest diversity of volatile tellurium compounds. All strains also produced methylated sulfur compounds, primarily dimethyldisulfide. Intracellular tellurium precipitates were a major product of tellurite metabolism in all strains tested, with nearly complete recovery of the tellurite initially provided to cultures as a precipitate. Different strains appeared to produce different shapes and sizes of tellurium containing nanostructures. These studies suggest that aerobic marine yeast and Bacillus spp. may play a greater role in trace element biogeochemistry than has been previously assumed, though additional work is needed to further define and quantify their specific contributions.

Volatilization and Precipitation of Tellurium by Aerobic, Tellurite-Resistant Marine Microbes▿ †

PubMed Central

Ollivier, Patrick R. L.; Bahrou, Andrew S.; Marcus, Sarah; Cox, Talisha; Church, Thomas M.; Hanson, Thomas E.

2008-01-01

Microbial resistance to tellurite, an oxyanion of tellurium, is widespread in the biosphere, but the geochemical significance of this trait is poorly understood. As some tellurite resistance markers appear to mediate the formation of volatile tellurides, the potential contribution of tellurite-resistant microbial strains to trace element volatilization in salt marsh sediments was evaluated. Microbial strains were isolated aerobically on the basis of tellurite resistance and subsequently examined for their capacity to volatilize tellurium in pure cultures. The tellurite-resistant strains recovered were either yeasts related to marine isolates of Rhodotorula spp. or gram-positive bacteria related to marine strains within the family Bacillaceae based on rRNA gene sequence comparisons. Most strains produced volatile tellurides, primarily dimethyltelluride, though there was a wide range of the types and amounts of species produced. For example, the Rhodotorula spp. produced the greatest quantities and highest diversity of volatile tellurium compounds. All strains also produced methylated sulfur compounds, primarily dimethyldisulfide. Intracellular tellurium precipitates were a major product of tellurite metabolism in all strains tested, with nearly complete recovery of the tellurite initially provided to cultures as a precipitate. Different strains appeared to produce different shapes and sizes of tellurium containing nanostructures. These studies suggest that aerobic marine yeast and Bacillus spp. may play a greater role in trace element biogeochemistry than has been previously assumed, though additional work is needed to further define and quantify their specific contributions. PMID:18849455

The secretory pathway: exploring yeast diversity.

PubMed

Delic, Marizela; Valli, Minoska; Graf, Alexandra B; Pfeffer, Martin; Mattanovich, Diethard; Gasser, Brigitte

2013-11-01

Protein secretion is an essential process for living organisms. In eukaryotes, this encompasses numerous steps mediated by several hundred cellular proteins. The core functions of translocation through the endoplasmic reticulum membrane, primary glycosylation, folding and quality control, and vesicle-mediated secretion are similar from yeasts to higher eukaryotes. However, recent research has revealed significant functional differences between yeasts and mammalian cells, and even among diverse yeast species. This review provides a current overview of the canonical protein secretion pathway in the model yeast Saccharomyces cerevisiae, highlighting differences to mammalian cells as well as currently unresolved questions, and provides a genomic comparison of the S. cerevisiae pathway to seven other yeast species where secretion has been investigated due to their attraction as protein production platforms, or for their relevance as pathogens. The analysis of Candida albicans, Candida glabrata, Kluyveromyces lactis, Pichia pastoris, Hansenula polymorpha, Yarrowia lipolytica, and Schizosaccharomyces pombe reveals that many - but not all - secretion steps are more redundant in S. cerevisiae due to duplicated genes, while some processes are even absent in this model yeast. Recent research obviates that even where homologous genes are present, small differences in protein sequence and/or differences in the regulation of gene expression may lead to quite different protein secretion phenotypes. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Yeasts are essential for cocoa bean fermentation.

PubMed

Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

2014-03-17

Cocoa beans (Theobroma cacao) are the major raw material for chocolate production and fermentation of the beans is essential for the development of chocolate flavor precursors. In this study, a novel approach was used to determine the role of yeasts in cocoa fermentation and their contribution to chocolate quality. Cocoa bean fermentations were conducted with the addition of 200ppm Natamycin to inhibit the growth of yeasts, and the resultant microbial ecology and metabolism, bean chemistry and chocolate quality were compared with those of normal (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii and Kluyveromyces marxianus, the lactic acid bacteria Lactobacillus plantarum and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in the control fermentation. In fermentations with the presence of Natamycin, the same bacterial species grew but yeast growth was inhibited. Physical and chemical analyses showed that beans fermented without yeasts had increased shell content, lower production of ethanol, higher alcohols and esters throughout fermentation and lesser presence of pyrazines in the roasted product. Quality tests revealed that beans fermented without yeasts were purplish-violet in color and not fully brown, and chocolate prepared from these beans tasted more acid and lacked characteristic chocolate flavor. Beans fermented with yeast growth were fully brown in color and gave chocolate with typical characters which were clearly preferred by sensory panels. Our findings demonstrate that yeast growth and activity were essential for cocoa bean fermentation and the development of chocolate characteristics. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Bioactivity studies of extracts from Tridax procumbens.

PubMed

Taddei, A; Rosas-Romero, A J

2000-06-01

An updated review on the biological activity of Tridax procumbens is presented. A detailed biological screening comprised of gram-positive and gram-negative bacteria, yeasts and fungi using crude extracts of this plant was undertaken. The n-hexane extract of the flowers showed activity against Escherichia coli. The same extract of the whole aerial parts was active against Mycobacterium smegmatis, Escherichia coli, Salmonella group C and Salmonella paratyphi. The ethyl-acetate extract of the flowers was active against Bacillus cereus and Klebsiella sp. The aerial parts extract also showed activity only against Mycobacterium smegmatis and Staphylococcus aureus, while the aqueous extract showed no antimicrobial activity. None of the tested extracts was active against the yeasts, Candida albicans, Candida tropicalis and Rhodotorula rubra; or the fungi: Aspergillus flavus, Aspergillus niger, Mucor sp. and Trichophyton rubrum.

Yeast Genetics and Biotechnological Applications

NASA Astrophysics Data System (ADS)

Mishra, Saroj; Baranwal, Richa

Yeast can be recognized as one of the very important groups of microorganisms on account of its extensive use in the fermentation industry and as a basic eukaryotic model cellular system. The yeast Saccharomyces cerevisiae has been extensively used to elucidate the genetics and regulation of several key functions in the cell such as cell mating, electron transport chain, protein trafficking, cell cycle events and others. Even before the genome sequence of the yeast was out, the structural organization and function of several of its genes was known. With the availability of the origin of replication from the 2 μm plasmid and the development of transformation system, it became the host of choice for expression of a number of important proteins. A large number of episomal and integrative shuttle vectors are available for expression of mammalian proteins. The latest developments in genomics and micro-array technology have allowed investigations of individual gene function by site-specific deletion method. The application of metabolic profiling has also assisted in understanding the cellular network operating in this yeast. This chapter is aimed at reviewing the use of this system as an experimental tool for conducting classical genetics. Various vector systems available, foreign genes expressed and the limitations as a host will be discussed. Finally, the use of various yeast enzymes in biotechnology sector will be reviewed.

Functional adaptation between yeast actin and its cognate myosin motors.

PubMed

Stark, Benjamin C; Wen, Kuo-Kuang; Allingham, John S; Rubenstein, Peter A; Lord, Matthew

2011-09-02

We employed budding yeast and skeletal muscle actin to examine the contribution of the actin isoform to myosin motor function. While yeast and muscle actin are highly homologous, they exhibit different charge density at their N termini (a proposed myosin-binding interface). Muscle myosin-II actin-activated ATPase activity is significantly higher with muscle versus yeast actin. Whether this reflects inefficiency in the ability of yeast actin to activate myosin is not known. Here we optimized the isolation of two yeast myosins to assess actin function in a homogenous system. Yeast myosin-II (Myo1p) and myosin-V (Myo2p) accommodate the reduced N-terminal charge density of yeast actin, showing greater activity with yeast over muscle actin. Increasing the number of negative charges at the N terminus of yeast actin from two to four (as in muscle) had little effect on yeast myosin activity, while other substitutions of charged residues at the myosin interface of yeast actin reduced activity. Thus, yeast actin functions most effectively with its native myosins, which in part relies on associations mediated by its outer domain. Compared with yeast myosin-II and myosin-V, muscle myosin-II activity was very sensitive to salt. Collectively, our findings suggest differing degrees of reliance on electrostatic interactions during weak actomyosin binding in yeast versus muscle. Our study also highlights the importance of native actin isoforms when considering the function of myosins.

Genomic Evolution of the Ascomycete Yeasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riley, Robert; Haridas, Sajeet; Salamov, Asaf

2015-03-16

Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphrinomycotina. Phylogenetic analysis of these and previously published yeast genomes helped resolve the placement of species including Saitoella complicata, Babjeviella inositovora, Hyphopichia burtonii, and Metschnikowia bicuspidata. Moreover, we find that alternative nuclear codon usage, where CUG encodes serine instead of leucine, are monophyletic within the Saccharomycotina. Most of the yeasts have compact genomes with a large fraction of single exon genes, and amore » tendency towards more introns in early-diverging species. Analysis of enzyme phylogeny gives insights into the evolution of metabolic capabilities such as methanol utilization and assimilation of alternative carbon sources.« less

Specialist nectar-yeasts decline with urbanization in Berlin

NASA Astrophysics Data System (ADS)

Wehner, Jeannine; Mittelbach, Moritz; Rillig, Matthias C.; Verbruggen, Erik

2017-03-01

Nectar yeasts are common inhabitants of insect-pollinated flowers but factors determining their distribution are not well understood. We studied the influence of host identity, environmental factors related to pollution/urbanization, and the distance to a target beehive on local distribution of nectar yeasts within Robinia pseudoacacia L. and Tilia tomentosa Moench in Berlin, Germany. Nectar samples of six individuals per species were collected at seven sites in a 2 km radius from each target beehive and plated on YM-Agar to visualise the different morphotypes, which were then identified by sequencing a section of the 26S rDNA gene. Multivariate linear models were used to analyze the effects of all investigated factors on yeast occurrence per tree. Yeast distribution was mainly driven by host identity. The influence of the environmental factors (NO2, height of construction, soil sealing) strongly depended on the radius around the tree, similar to the distance of the sampled beehive. Incidence of specialist nectar-borne yeast species decreased with increasing pollution/urbanization index. Given that specialist yeast species gave way to generalist yeasts that have a reduced dependency on pollinators for between-flower dispersal, our results indicate that increased urbanization may restrict the movement of nectar-specialized yeasts, via limitations of pollinator foraging behavior.

Accumulation and metabolism of selenium by yeast cells.

PubMed

Kieliszek, Marek; Błażejak, Stanisław; Gientka, Iwona; Bzducha-Wróbel, Anna

2015-07-01

This paper examines the process of selenium bioaccumulation and selenium metabolism in yeast cells. Yeast cells can bind elements in ionic from the environment and permanently integrate them into their cellular structure. Up to now, Saccharomyces cerevisiae, Candida utilis, and Yarrowia lipolytica yeasts have been used primarily in biotechnological studies to evaluate binding of minerals. Yeast cells are able to bind selenium in the form of both organic and inorganic compounds. The process of bioaccumulation of selenium by microorganisms occurs through two mechanisms: extracellular binding by ligands of membrane assembly and intracellular accumulation associated with the transport of ions across the cytoplasmic membrane into the cell interior. During intracellular metabolism of selenium, oxidation, reduction, methylation, and selenoprotein synthesis processes are involved, as exemplified by detoxification processes that allow yeasts to survive under culture conditions involving the elevated selenium concentrations which were observed. Selenium yeasts represent probably the best absorbed form of this element. In turn, in terms of wide application, the inclusion of yeast with accumulated selenium may aid in lessening selenium deficiency in a diet.

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

PubMed Central

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

2013-01-01

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

Yeast Can Affect Behavior and Learning.

ERIC Educational Resources Information Center

Crook, William G.

1984-01-01

A pediatrician recounts his experiences in diagnosing and treating allergies to common yeast germs that may result in behavior and learning problems. He lists characteristics that may predispose children to yeast-connected health problems. (CL)

Chemical signaling and insect attraction is a conserved trait in yeasts.

PubMed

Becher, Paul G; Hagman, Arne; Verschut, Vasiliki; Chakraborty, Amrita; Rozpędowska, Elżbieta; Lebreton, Sébastien; Bengtsson, Marie; Flick, Gerhard; Witzgall, Peter; Piškur, Jure

2018-03-01

Yeast volatiles attract insects, which apparently is of mutual benefit, for both yeasts and insects. However, it is unknown whether biosynthesis of metabolites that attract insects is a basic and general trait, or if it is specific for yeasts that live in close association with insects. Our goal was to study chemical insect attractants produced by yeasts that span more than 250 million years of evolutionary history and vastly differ in their metabolism and lifestyle. We bioassayed attraction of the vinegar fly Drosophila melanogaster to odors of phylogenetically and ecologically distinct yeasts grown under controlled conditions. Baker's yeast Saccharomyces cerevisiae , the insect-associated species Candida californica , Pichia kluyveri and Metschnikowia andauensis , wine yeast Dekkera bruxellensis , milk yeast Kluyveromyces lactis , the vertebrate pathogens Candida albicans and Candida glabrata , and oleophilic Yarrowia lipolytica were screened for fly attraction in a wind tunnel. Yeast headspace was chemically analyzed, and co-occurrence of insect attractants in yeasts and flowering plants was investigated through a database search. In yeasts with known genomes, we investigated the occurrence of genes involved in the synthesis of key aroma compounds. Flies were attracted to all nine yeasts studied. The behavioral response to baker's yeast was independent of its growth stage. In addition to Drosophila , we tested the basal hexapod Folsomia candida (Collembola) in a Y-tube assay to the most ancient yeast, Y. lipolytica, which proved that early yeast signals also function on clades older than neopteran insects. Behavioral and chemical data and a search for selected genes of volatile metabolites underline that biosynthesis of chemical signals is found throughout the yeast clade and has been conserved during the evolution of yeast lifestyles. Literature and database reviews corroborate that yeast signals mediate mutualistic interactions between insects and yeasts

Risk assessment for the spread of Candida sp. in dental chair unit waterlines using molecular techniques.

PubMed

Mazari, Wissame; Boucherit-Otmani, Zahia; El Haci, Imad Abdelhamid; Ilahi, Amine; Boucherit, Kebir

2018-05-04

The aim of this study was to evaluate the presence of yeasts in dental chair unit waterlines (DCUWLs) and to test their ability to form biofilms. Eighteen dental waterlines were analysed by culture in liquid Sabouraud in order to allow the quantification and the purification of isolated yeasts from their internal surfaces. All isolates were identified by standard laboratory procedures, including CHROMagar Candida medium for orientation, commercial yeast identification system Api Candida, MALDI-TOF MS and DNA sequencing. To evaluate their kinetics of antifungal susceptibility during different phases of biofilm formation, these yeasts were subjected to three antifungal agents. From the 18 DCUWLs studied, 10 were altered (55.56%). Eleven strains of Candida sp. [Candida albicans (2), Candida guilliermondii (5) and Candida glabrata (4)] and two species of non-Candida; Rhodotorula spp. (1) and Trichosporon spp. (2) were identified. The majority of yeasts in planktonic form were susceptible to amphotericin B, caspofungin and voriconazole, except C. albicans was resistant to voriconazole. In the biofilm form, caspofungin was the most effective antifungal agent for all isolated strains. For the other antifungal agents, sessile cells were resistant. Several types of yeasts were identified; the most frequently isolated genus was Candida. The majority of these yeasts had the ability to form biofilms and resisted antifungal agents used in this study. © 2018 FDI World Dental Federation.

Yeast as a model for Ras signalling.

PubMed

Tisi, Renata; Belotti, Fiorella; Martegani, Enzo

2014-01-01

For centuries yeast species have been popular hosts for classical biotechnology processes, such as baking, brewing, and wine making, and more recently for recombinant proteins production, thanks to the advantages of unicellular organisms (i.e., ease of genetic manipulation and rapid growth) together with the ability to perform eukaryotic posttranslational modifications. Moreover, yeast cells have been used for few decades as a tool for identifying the genes and pathways involved in basic cellular processes such as the cell cycle, aging, and stress response. In the budding yeast S. cerevisiae the Ras/cAMP/PKA pathway is directly involved in the regulation of metabolism, cell growth, stress resistance, and proliferation in response to the availability of nutrients and in the adaptation to glucose, controlling cytosolic cAMP levels and consequently the cAMP-dependent protein kinase (PKA) activity. Moreover, Ras signalling has been identified in several pathogenic yeasts as a key controller for virulence, due to its involvement in yeast morphogenesis. Nowadays, yeasts are still useful for Ras-like proteins investigation, both as model organisms and as a test tube to study variants of heterologous Ras-like proteins.

Flor Yeast: New Perspectives Beyond Wine Aging

PubMed Central

Legras, Jean-Luc; Moreno-Garcia, Jaime; Zara, Severino; Zara, Giacomo; Garcia-Martinez, Teresa; Mauricio, Juan C.; Mannazzu, Ilaria; Coi, Anna L.; Bou Zeidan, Marc; Dequin, Sylvie; Moreno, Juan; Budroni, Marilena

2016-01-01

The most important dogma in white-wine production is the preservation of the wine aroma and the limitation of the oxidative action of oxygen. In contrast, the aging of Sherry and Sherry-like wines is an aerobic process that depends on the oxidative activity of flor strains of Saccharomyces cerevisiae. Under depletion of nitrogen and fermentable carbon sources, these yeast produce aggregates of floating cells and form an air–liquid biofilm on the wine surface, which is also known as velum or flor. This behavior is due to genetic and metabolic peculiarities that differentiate flor yeast from other wine yeast. This review will focus first on the most updated data obtained through the analysis of flor yeast with -omic tools. Comparative genomics, proteomics, and metabolomics of flor and wine yeast strains are shedding new light on several features of these special yeast, and in particular, they have revealed the extent of proteome remodeling imposed by the biofilm life-style. Finally, new insights in terms of promotion and inhibition of biofilm formation through small molecules, amino acids, and di/tri-peptides, and novel possibilities for the exploitation of biofilm immobilization within a fungal hyphae framework, will be discussed. PMID:27148192

Physiological and environmental control of yeast prions

PubMed Central

Chernova, Tatiana A.; Wilkinson, Keith D.; Chernoff, Yury O.

2014-01-01

Prions are self-perpetuating protein isoforms that cause fatal and incurable neurodegenerative disease in mammals. Recent evidence indicates that a majority of human proteins involved in amyloid and neural inclusion disorders possess at least some prion properties. In lower eukaryotes, such as yeast, prions act as epigenetic elements, which increase phenotypic diversity by altering a range of cellular processes. While some yeast prions are clearly pathogenic, it is also postulated that prion formation could be beneficial in variable environmental conditions. Yeast and mammalian prions have similar molecular properties. Crucial cellular factors and conditions influencing prion formation and propagation were uncovered in the yeast models. Stress-related chaperones, protein quality control deposits, degradation pathways and cytoskeletal networks control prion formation and propagation in yeast. Environmental stresses trigger prion formation and loss, supposedly acting via influencing intracellular concentrations of the prion-inducing proteins, and/or by localizing prionogenic proteins to the prion induction sites via heterologous ancillary helpers. Physiological and environmental modulation of yeast prions points to new opportunities for pharmacological intervention and/or prophylactic measures targeting general cellular systems rather than the properties of individual amyloids and prions. PMID:24236638

Isolation and characterization of ethanol tolerant yeast strains

PubMed Central

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

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

Phylogenetics of Saccharomycetales, the ascomycete yeasts.

PubMed

Suh, Sung-Oui; Blackwell, Meredith; Kurtzman, Cletus P; Lachance, Marc-André

2006-01-01

Ascomycete yeasts (phylum Ascomycota: subphylum Saccharomycotina: class Saccharomycetes: order Saccharomycetales) comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as saprobes, often in association with plants, animals and their interfaces. A few species account for most human mycotic infections, and fewer than 10 species are plant pathogens. Yeasts are responsible for important industrial and biotechnological processes, including baking, brewing and synthesis of recombinant proteins. Species such as Saccharomyces cerevisiae are model organisms in research, some of which led to a Nobel Prize. Yeasts usually reproduce asexually by budding, and their sexual states are not enclosed in a fruiting body. The group also is well defined by synapomorphies visible at the ultrastructural level. Yeast identification and classification changed dramatically with the availability of DNA sequencing. Species identification now benefits from a constantly updated sequence database and no longer relies on ambiguous growth tests. A phylogeny based on single gene analyses has shown the order to be remarkably divergent despite morphological similarities among members. The limits of many previously described genera are not supported by sequence comparisons, and multigene phylogenetic studies are under way to provide a stable circumscription of genera, families and orders. One recent multigene study has resolved species of the Saccharomycetaceae into genera that differ markedly from those defined by analysis of morphology and growth responses, and similar changes are likely to occur in other branches of the yeast tree as additional sequences become available.

Yeast species associated with wine grapes in China.

PubMed

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

2010-03-31

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

Antimicrobial activity of yeasts against some pathogenic bacteria

PubMed Central

Younis, Gamal; Awad, Amal; Dawod, Rehab E.; Yousef, Nehal E.

2017-01-01

Aim: This study was designed to isolate and identify yeast species from milk and meat products, and to test their antimicrobial activity against some bacterial species. Materials and Methods: A total of 160 milk and meat products samples were collected from random sellers and super markets in New Damietta city, Damietta, Egypt. Samples were subjected to yeast isolation procedures and tested for its antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In addition, all yeast species isolates were subjected to polymerase chain reaction (PCR) for detection of khs (kievitone hydratase) and pelA (pectate degrading enzyme)genes. Results: The recovery rate of yeasts from sausage was 20% (2/10) followed by kareish cheese, processed cheese, and butter 10% (1/10) each as well as raw milk 9% (9/100), and fruit yoghurt 30% (6/20). Different yeast species were recovered, namely, Candida kefyr (5 isolates), Saccharomyces cerevisiae (4 isolates), Candida intermedia (3 isolates), Candida tropicalis (2 isolates), Candida lusitaniae (2 isolates), and Candida krusei (1 isolate). khs gene was detected in all S. cerevisiae isolates, however, pelA gene was not detected in all identified yeast species. Antimicrobial activity of recovered yeasts against the selected bacterial species showed high activity with C. intermedia against S. aureus and E. coli, C. kefyr against E. coli, and C. lusitaniae against S. aureus. Moderate activities were obtained with C. tropicalis, C. lusitaniae, and S. cerevisiae against E. coli; meanwhile, all the tested yeasts revealed a very low antimicrobial activity against P. aeruginosa. Conclusion: The obtained results confirmed that some kinds of yeasts have the ability to produce antimicrobial compounds that could inhibit some pathogenic and spoilage bacteria and these antimicrobial activity of yeasts enables them to be one of the novel agents in controlling spoilage of food. PMID:28919693

Genomic evolution of the ascomycetous yeasts

USDA-ARS?s Scientific Manuscript database

Yeasts are important for industrial and biotechnological processes and show remarkable metabolic and phylogenetic diversity despite morphological similarities. We have sequenced the genomes of 16 ascomycete yeasts of taxonomic and industrial importance including members of Saccharomycotina and Taphr...

Repeat-Associated Fission Yeast-Like Regional Centromeres in the Ascomycetous Budding Yeast Candida tropicalis

PubMed Central

Chatterjee, Gautam; Sankaranarayanan, Sundar Ram; Guin, Krishnendu; Thattikota, Yogitha; Padmanabhan, Sreedevi; Siddharthan, Rahul; Sanyal, Kaustuv

2016-01-01

The centromere, on which kinetochore proteins assemble, ensures precise chromosome segregation. Centromeres are largely specified by the histone H3 variant CENP-A (also known as Cse4 in yeasts). Structurally, centromere DNA sequences are highly diverse in nature. However, the evolutionary consequence of these structural diversities on de novo CENP-A chromatin formation remains elusive. Here, we report the identification of centromeres, as the binding sites of four evolutionarily conserved kinetochore proteins, in the human pathogenic budding yeast Candida tropicalis. Each of the seven centromeres comprises a 2 to 5 kb non-repetitive mid core flanked by 2 to 5 kb inverted repeats. The repeat-associated centromeres of C. tropicalis all share a high degree of sequence conservation with each other and are strikingly diverged from the unique and mostly non-repetitive centromeres of related Candida species—Candida albicans, Candida dubliniensis, and Candida lusitaniae. Using a plasmid-based assay, we further demonstrate that pericentric inverted repeats and the underlying DNA sequence provide a structural determinant in CENP-A recruitment in C. tropicalis, as opposed to epigenetically regulated CENP-A loading at centromeres in C. albicans. Thus, the centromere structure and its influence on de novo CENP-A recruitment has been significantly rewired in closely related Candida species. Strikingly, the centromere structural properties along with role of pericentric repeats in de novo CENP-A loading in C. tropicalis are more reminiscent to those of the distantly related fission yeast Schizosaccharomyces pombe. Taken together, we demonstrate, for the first time, fission yeast-like repeat-associated centromeres in an ascomycetous budding yeast. PMID:26845548

Chemical mechanism of D-amino acid oxidase from Rhodotorula gracilis: pH dependence of kinetic parameters.

PubMed Central

Ramón, F; Castillón, M; De La Mata, I; Acebal, C

1998-01-01

The variation of kinetic parameters of d-amino acid oxidase from Rhodotorula gracilis with pH was used to gain information about the chemical mechanism of the oxidation of D-amino acids catalysed by this flavoenzyme. d-Alanine was the substrate used. The pH dependence of Vmax and Vmax/Km for alanine as substrate showed that a group with a pK value of 6.26-7.95 (pK1) must be unprotonated and a group with a pK of 10.8-9.90 (pK2) must be protonated for activity. The lower pK value corresponded to a group on the enzyme involved in catalysis and whose protonation state was not important for binding. The higher pK value was assumed to be the amino group of the substrate. Profiles of pKi for D-aspartate as competitive inhibitor showed that binding is prevented when a group on the enzyme with a pK value of 8.4 becomes unprotonated; this basic group was not detected in Vmax/Km profiles suggesting its involvement in binding of the beta-carboxylic group of the inhibitor. PMID:9461524

Comparative genomics of biotechnologically important yeasts

USDA-ARS?s Scientific Manuscript database

Ascomycete yeasts are metabolically diverse, with great potential for biotechnology. Here, we report the comparative genome analysis of 29 taxonomically and biotechnologically important yeasts, including 16 newly sequenced. We identify a genetic code change, CUG-Ala, in Pachysolen tannophilus in the...

Counting Yeast.

ERIC Educational Resources Information Center

Bealer, Jonathan; Welton, Briana

1998-01-01

Describes changes to a traditional study of population in yeast colonies. Changes to the procedures include: (1) only one culture per student team; (2) cultures are inoculated only once; and (3) the same tube is sampled daily. (DDR)

Yeast diversity and native vigor for flavor phenotypes.

PubMed

Carrau, Francisco; Gaggero, Carina; Aguilar, Pablo S

2015-03-01

Saccharomyces cerevisiae, the yeast used widely for beer, bread, cider, and wine production, is the most resourceful eukaryotic model used for genetic engineering. A typical concern about using engineered yeasts for food production might be negative consumer perception of genetically modified organisms. However, we believe the true pitfall of using genetically modified yeasts is their limited capacity to either refine or improve the sensory properties of fermented foods under real production conditions. Alternatively, yeast diversity screening to improve the aroma and flavors could offer groundbreaking opportunities in food biotechnology. We propose a 'Yeast Flavor Diversity Screening' strategy which integrates knowledge from sensory analysis and natural whole-genome evolution with information about flavor metabolic networks and their regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Making Sense of the Yeast Sphingolipid Pathway.

PubMed

Megyeri, Márton; Riezman, Howard; Schuldiner, Maya; Futerman, Anthony H

2016-12-04

Sphingolipids (SL) and their metabolites play key roles both as structural components of membranes and as signaling molecules. Many of the key enzymes and regulators of SL metabolism were discovered using the yeast Saccharomyces cerevisiae, and based on the high degree of conservation, a number of mammalian homologs were identified. Although yeast continues to be an important tool for SL research, the complexity of SL structure and nomenclature often hampers the ability of new researchers to grasp the subtleties of yeast SL biology and discover new modulators of this intricate pathway. Moreover, the emergence of lipidomics by mass spectrometry has enabled the rapid identification of SL species in yeast and rendered the analysis of SL composition under various physiological and pathophysiological conditions readily amenable. However, the complex nomenclature of the identified species renders much of the data inaccessible to non-specialists. In this review, we focus on parsing both the classical SL nomenclature and the nomenclature normally used during mass spectrometry analysis, which should facilitate the understanding of yeast SL data and might shed light on biological processes in which SLs are involved. Finally, we discuss a number of putative roles of various yeast SL species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel brewing yeast hybrids: creation and application.

PubMed

Krogerus, Kristoffer; Magalhães, Frederico; Vidgren, Virve; Gibson, Brian

2017-01-01

The natural interspecies Saccharomyces cerevisiae × Saccharomyces eubayanus hybrid yeast is responsible for global lager beer production and is one of the most important industrial microorganisms. Its success in the lager brewing environment is due to a combination of traits not commonly found in pure yeast species, principally low-temperature tolerance, and maltotriose utilization. Parental transgression is typical of hybrid organisms and has been exploited previously for, e.g., the production of wine yeast with beneficial properties. The parental strain S. eubayanus has only been discovered recently and newly created lager yeast strains have not yet been applied industrially. A number of reports attest to the feasibility of this approach and artificially created hybrids are likely to have a significant impact on the future of lager brewing. De novo S. cerevisiae × S. eubayanus hybrids outperform their parent strains in a number of respects, including, but not restricted to, fermentation rate, sugar utilization, stress tolerance, and aroma formation. Hybrid genome function and stability, as well as different techniques for generating hybrids and their relative merits are discussed. Hybridization not only offers the possibility of generating novel non-GM brewing yeast strains with unique properties, but is expected to aid in unraveling the complex evolutionary history of industrial lager yeast.

Improving industrial yeast strains: exploiting natural and artificial diversity

PubMed Central

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

2014-01-01

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

Comparative genomics of biotechnologically important yeasts

USDA-ARS?s Scientific Manuscript database

Saccharomyces cerevisiae, is used in the vast majority of the world’s bioprocesses, and its economic significance is unchallenged. It, however, represents only a small slice of yeast physiological diversity. Many other yeasts, are used in lesser known, but commercially important processes that take ...

The yeast Golgi apparatus: insights and mysteries

PubMed Central

Papanikou, Effrosyni; Glick, Benjamin S.

2009-01-01

The Golgi apparatus is known to modify and sort newly synthesized secretory proteins. However, fundamental mysteries remain about the structure, operation, and dynamics of this organelle. Important insights have emerged from studying the Golgi in yeasts. For example, yeasts have provided direct evidence for Golgi cisternal maturation, a mechanism that is likely to be broadly conserved. Here, we highlight features of the yeast Golgi as well as challenges that lie ahead. PMID:19879270

Evolution and variation of the yeast (Saccharomyces) genome.

PubMed

Mortimer, R K

2000-04-01

In this review we describe the role of the yeast Saccharomyces in the development of human societies including the use of this organism in the making of wine, bread, beer, and distilled beverages. We also discuss the tremendous diversity of yeast found in natural (i.e., noninoculated) wine fermentations and the scientific uses of yeast over the past 60 years. In conclusion, we present ideas on the model of "genome renewal" and the use of this model to explain the mode by which yeast has evolved and how diversity can be generated.

Brewer's/baker's yeast (Saccharomyces cerevisiae) and preventive medicine: Part II.

PubMed

Moyad, Mark A

2008-02-01

Yeast is the term generally applied to a unicellular fungus, and there are hundreds of species now identified. One of the most notable and well-known species of yeast in health and wellness is known as Saccharomyces cerevisiae, which is also known by its more common names, brewer's yeast or baker's yeast. Typically, brewer's yeast is used as a protein supplement, energy booster, immune enhancer, or other vehicle where other compounds can be inserted to create a commercialized health product. For example, one of the most notable positive findings was the encouraging results from a large randomized trial of adults recently vaccinated for seasonal influenza who also received an over-the-counter daily adjuvant modified brewer's yeast-based product (EpiCor) to prevent colds and flu symptoms. The modified yeast-based product significantly reduced the incidence and duration of this common condition. Yeast-based technology is also being used as a molecular mechanistic model of caloric restriction (CR) with the goal of improving the human life span. The current and potential impact of yeast-based technology in medicine is encouraging and should receive more attention, but the recent preliminary positive results of CR in humans may be in part due to what has been already learned from brewer's yeast.

The yeast spectrum of the 'tea fungus Kombucha'.

PubMed

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

1995-01-01

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

[Yeast species in vulvovaginitis candidosa].

PubMed

Nemes-Nikodém, Éva; Tamási, Béla; Mihalik, Noémi; Ostorházi, Eszter

2015-01-04

Vulvovaginal candidiasis is the most common mycosis, however, the available information about antifungal susceptibilities of these yeasts is limited. To compare the gold standard fungal culture with a new molecular identification method and report the incidence of yeast species in vulvovaginitis candidosa. The authors studied 370 yeasts isolated from vulvovaginal candidiasis and identified them by phenotypic and molecular methods. The most common species was Candida albicans (85%), followed by Candida glabrata, and other Candida species. At present there are no recommendations for the evaluation of antifungal susceptibility of pathogenic fungal species occurring in vulvovaginal candidiasis and the natural antifungal resistance of the different species is known only. Matrix Assisted Laser Desorption Ionization Time of Flight identification can be used to differentiate the fluconazole resistant Candida dubliniensis and the sensitive Candida albicans strains.

21 CFR 172.381 - Vitamin D2 bakers yeast.

Code of Federal Regulations, 2014 CFR

2014-04-01

... conventional bakers yeast. (c) The additive may be used in yeast-leavened baked goods and baking mixes and yeast-leavened baked snack foods at levels not to exceed 400 International Units of vitamin D2 per 100...

Anaerobic digestion of food waste using yeast.

PubMed

Suwannarat, Jutarat; Ritchie, Raymond J

2015-08-01

Fermentative breakdown of food waste seems a plausible alternative to feeding food waste to pigs, incineration or garbage disposal in tourist areas. We determined the optimal conditions for the fermentative breakdown of food waste using yeast (Saccharomyces cerevisiae) in incubations up to 30days. Yeast efficiently broke down food waste with food waste loadings as high as 700g FW/l. The optimum inoculation was ≈46×10(6)cells/l of culture with a 40°C optimum (25-40°C). COD and BOD were reduced by ≈30-50%. Yeast used practically all the available sugars and reduced proteins and lipids by ≈50%. Yeast was able to metabolize lipids much better than expected. Starch was mobilized after very long term incubations (>20days). Yeast was effective in breaking down the organic components of food waste but CO2 gas and ethanol production (≈1.5%) were only significant during the first 7days of incubations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nectar yeasts: a natural microcosm for ecology.

PubMed

Chappell, Callie R; Fukami, Tadashi

2018-06-01

The species of yeasts that colonize floral nectar can modify the mutualistic relationships between plants and pollinators by changing the chemical properties of nectar. Recent evidence supporting this possibility has led to increased interest among ecologists in studying these fungi as well as the bacteria that interact with them in nectar. Although not fully explored, nectar yeasts also constitute a promising natural microcosm that can be used to facilitate development of general ecological theory. We discuss the methodological and conceptual advantages of using nectar yeasts from this perspective, including simplicity of communities, tractability of dispersal, replicability of community assembly, and the ease with which the mechanisms of species interactions can be studied in complementary experiments conducted in the field and the laboratory. To illustrate the power of nectar yeasts as a study system, we discuss several topics in community ecology, including environmental filtering, priority effects, and metacommunity dynamics. An exciting new direction is to integrate metagenomics and comparative genomics into nectar yeast research to address these fundamental ecological topics. Copyright © 2018 John Wiley & Sons, Ltd.

Kinetics of growth and sugar consumption in yeasts.

PubMed

van Dijken, J P; Weusthuis, R A; Pronk, J T

1993-01-01

An overview is presented of the steady- and transient state kinetics of growth and formation of metabolic byproducts in yeasts. Saccharomyces cerevisiae is strongly inclined to perform alcoholic fermentation. Even under fully aerobic conditions, ethanol is produced by this yeast when sugars are present in excess. This so-called 'Crabtree effect' probably results from a multiplicity of factors, including the mode of sugar transport and the regulation of enzyme activities involved in respiration and alcoholic fermentation. The Crabtree effect in S. cerevisiae is not caused by an intrinsic inability to adjust its respiratory activity to high glycolytic fluxes. Under certain cultivation conditions, for example during growth in the presence of weak organic acids, very high respiration rates can be achieved by this yeast. S. cerevisiae is an exceptional yeast since, in contrast to most other species that are able to perform alcoholic fermentation, it can grow under strictly anaerobic conditions. 'Non-Saccharomyces' yeasts require a growth-limiting supply of oxygen (i.e. oxygen-limited growth conditions) to trigger alcoholic fermentation. However, complete absence of oxygen results in cessation of growth and therefore, ultimately, of alcoholic fermentation. Since it is very difficult to reproducibly achieve the right oxygen dosage in large-scale fermentations, non-Saccharomyces yeasts are therefore not suitable for large-scale alcoholic fermentation of sugar-containing waste streams. In these yeasts, alcoholic fermentation is also dependent on the type of sugar. For example, the facultatively fermentative yeast Candida utilis does not ferment maltose, not even under oxygen-limited growth conditions, although this disaccharide supports rapid oxidative growth.

The ecology of the Drosophila-yeast mutualism in wineries

PubMed Central

2018-01-01

The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila. PMID:29768432

The ecology of the Drosophila-yeast mutualism in wineries.

PubMed

Quan, Allison S; Eisen, Michael B

2018-01-01

The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila.

Improving industrial yeast strains: exploiting natural and artificial diversity.

PubMed

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

2014-09-01

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. © 2014 The Authors. FEMS Microbiology Reviews published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

Chromosomal Aneuploidy Improves the Brewing Characteristics of Sake Yeast.

PubMed

Kadowaki, Masafumi; Fujimaru, Yuki; Taguchi, Seiga; Ferdouse, Jannatul; Sawada, Kazutaka; Kimura, Yuta; Terasawa, Yohei; Agrimi, Gennaro; Anai, Toyoaki; Noguchi, Hideki; Toyoda, Atsushi; Fujiyama, Asao; Akao, Takeshi; Kitagaki, Hiroshi

2017-12-15

The effect of chromosomal aneuploidy on the brewing characteristics of brewery yeasts has not been studied. Here we report that chromosomal aneuploidy in sake brewery yeast ( Saccharomyces cerevisiae ) leads to the development of favorable brewing characteristics. We found that pyruvate-underproducing sake yeast, which produces less off-flavor diacetyl, is aneuploid and trisomic for chromosomes XI and XIV. To confirm that this phenotype is due to aneuploidy, we obtained 45 haploids with various chromosomal additions and investigated their brewing profiles. A greater number of chromosomes correlated with a decrease in pyruvate production. Especially, sake yeast haploids with extra chromosomes in addition to chromosome XI produced less pyruvate than euploids. Mitochondrion-related metabolites and intracellular oxygen species in chromosome XI aneuploids were higher than those in euploids, and this effect was canceled in their "petite" strains, suggesting that an increase in chromosomes upregulated mitochondrial activity and decreased pyruvate levels. These findings suggested that an increase in chromosome number, including chromosome XI, in sake yeast haploids leads to pyruvate underproduction through the augmentation of mitochondrial activity. This is the first report proposing that aneuploidy in brewery yeasts improves their brewing profile. IMPORTANCE Chromosomal aneuploidy has not been evaluated in development of sake brewing yeast strains. This study shows the relationship between chromosomal aneuploidy and brewing characteristics of brewery yeast strains. High concentrations of pyruvate during sake storage give rise to α-acetolactate and, in turn, to high concentrations of diacetyl, which is considered an off-flavor. It was demonstrated that pyruvate-underproducing sake yeast is trisomic for chromosome XI and XIV. Furthermore, sake yeast haploids with extra chromosomes produced reduced levels of pyruvate and showed metabolic processes characteristic of

Chromosomal Aneuploidy Improves the Brewing Characteristics of Sake Yeast

PubMed Central

Kadowaki, Masafumi; Fujimaru, Yuki; Taguchi, Seiga; Ferdouse, Jannatul; Sawada, Kazutaka; Kimura, Yuta; Terasawa, Yohei; Agrimi, Gennaro; Anai, Toyoaki; Noguchi, Hideki; Toyoda, Atsushi; Fujiyama, Asao; Akao, Takeshi

2017-01-01

ABSTRACT The effect of chromosomal aneuploidy on the brewing characteristics of brewery yeasts has not been studied. Here we report that chromosomal aneuploidy in sake brewery yeast (Saccharomyces cerevisiae) leads to the development of favorable brewing characteristics. We found that pyruvate-underproducing sake yeast, which produces less off-flavor diacetyl, is aneuploid and trisomic for chromosomes XI and XIV. To confirm that this phenotype is due to aneuploidy, we obtained 45 haploids with various chromosomal additions and investigated their brewing profiles. A greater number of chromosomes correlated with a decrease in pyruvate production. Especially, sake yeast haploids with extra chromosomes in addition to chromosome XI produced less pyruvate than euploids. Mitochondrion-related metabolites and intracellular oxygen species in chromosome XI aneuploids were higher than those in euploids, and this effect was canceled in their “petite” strains, suggesting that an increase in chromosomes upregulated mitochondrial activity and decreased pyruvate levels. These findings suggested that an increase in chromosome number, including chromosome XI, in sake yeast haploids leads to pyruvate underproduction through the augmentation of mitochondrial activity. This is the first report proposing that aneuploidy in brewery yeasts improves their brewing profile. IMPORTANCE Chromosomal aneuploidy has not been evaluated in development of sake brewing yeast strains. This study shows the relationship between chromosomal aneuploidy and brewing characteristics of brewery yeast strains. High concentrations of pyruvate during sake storage give rise to α-acetolactate and, in turn, to high concentrations of diacetyl, which is considered an off-flavor. It was demonstrated that pyruvate-underproducing sake yeast is trisomic for chromosome XI and XIV. Furthermore, sake yeast haploids with extra chromosomes produced reduced levels of pyruvate and showed metabolic processes characteristic

21 CFR 172.325 - Bakers yeast protein.

Code of Federal Regulations, 2010 CFR

2010-04-01

... harmful microbial toxin. (d) The ingredient is used in food as a nutrient supplement as defined in § 170.3... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

21 CFR 172.325 - Bakers yeast protein.

Code of Federal Regulations, 2012 CFR

2012-04-01

... harmful microbial toxin. (d) The ingredient is used in food as a nutrient supplement as defined in § 170.3... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

21 CFR 172.325 - Bakers yeast protein.

Code of Federal Regulations, 2011 CFR

2011-04-01

... harmful microbial toxin. (d) The ingredient is used in food as a nutrient supplement as defined in § 170.3... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

21 CFR 172.325 - Bakers yeast protein.

Code of Federal Regulations, 2013 CFR

2013-04-01

... harmful microbial toxin. (d) The ingredient is used in food as a nutrient supplement as defined in § 170.3... Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

Mammalian amyloidogenic proteins promote prion nucleation in yeast.

PubMed

Chandramowlishwaran, Pavithra; Sun, Meng; Casey, Kristin L; Romanyuk, Andrey V; Grizel, Anastasiya V; Sopova, Julia V; Rubel, Aleksandr A; Nussbaum-Krammer, Carmen; Vorberg, Ina M; Chernoff, Yury O

2018-03-02

Fibrous cross-β aggregates (amyloids) and their transmissible forms (prions) cause diseases in mammals (including humans) and control heritable traits in yeast. Initial nucleation of a yeast prion by transiently overproduced prion-forming protein or its (typically, QN-rich) prion domain is efficient only in the presence of another aggregated (in most cases, QN-rich) protein. Here, we demonstrate that a fusion of the prion domain of yeast protein Sup35 to some non-QN-rich mammalian proteins, associated with amyloid diseases, promotes nucleation of Sup35 prions in the absence of pre-existing aggregates. In contrast, both a fusion of the Sup35 prion domain to a multimeric non-amyloidogenic protein and the expression of a mammalian amyloidogenic protein that is not fused to the Sup35 prion domain failed to promote prion nucleation, further indicating that physical linkage of a mammalian amyloidogenic protein to the prion domain of a yeast protein is required for the nucleation of a yeast prion. Biochemical and cytological approaches confirmed the nucleation of protein aggregates in the yeast cell. Sequence alterations antagonizing or enhancing amyloidogenicity of human amyloid-β (associated with Alzheimer's disease) and mouse prion protein (associated with prion diseases), respectively, antagonized or enhanced nucleation of a yeast prion by these proteins. The yeast-based prion nucleation assay, developed in our work, can be employed for mutational dissection of amyloidogenic proteins. We anticipate that it will aid in the identification of chemicals that influence initial amyloid nucleation and in searching for new amyloidogenic proteins in a variety of proteomes. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

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

PubMed

Gélinas, Pierre

2010-01-01

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.

Guidelines and recommendations on yeast cell death nomenclature.

PubMed

Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J; Breitenbach, Michael; Burhans, William C; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W; Grant, Chris M; Greenwood, Michael T; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D; Outeiro, Tiago F; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F; Sharon, Amir; Sigrist, Stephan J; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B; Tuite, Mick; Vögtle, F-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J; Zhao, Richard Y; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

2018-01-01

Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cel-lular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the defi-nition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differ-ential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death rou-tines that are relevant for the biology of (at least some species of) yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the au-thors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the pro-gress of this vibrant field of research.

Guidelines and recommendations on yeast cell death nomenclature

PubMed Central

Carmona-Gutierrez, Didac; Bauer, Maria Anna; Zimmermann, Andreas; Aguilera, Andrés; Austriaco, Nicanor; Ayscough, Kathryn; Balzan, Rena; Bar-Nun, Shoshana; Barrientos, Antonio; Belenky, Peter; Blondel, Marc; Braun, Ralf J.; Breitenbach, Michael; Burhans, William C.; Büttner, Sabrina; Cavalieri, Duccio; Chang, Michael; Cooper, Katrina F.; Côrte-Real, Manuela; Costa, Vítor; Cullin, Christophe; Dawes, Ian; Dengjel, Jörn; Dickman, Martin B.; Eisenberg, Tobias; Fahrenkrog, Birthe; Fasel, Nicolas; Fröhlich, Kai-Uwe; Gargouri, Ali; Giannattasio, Sergio; Goffrini, Paola; Gourlay, Campbell W.; Grant, Chris M.; Greenwood, Michael T.; Guaragnella, Nicoletta; Heger, Thomas; Heinisch, Jürgen; Herker, Eva; Herrmann, Johannes M.; Hofer, Sebastian; Jiménez-Ruiz, Antonio; Jungwirth, Helmut; Kainz, Katharina; Kontoyiannis, Dimitrios P.; Ludovico, Paula; Manon, Stéphen; Martegani, Enzo; Mazzoni, Cristina; Megeney, Lynn A.; Meisinger, Chris; Nielsen, Jens; Nyström, Thomas; Osiewacz, Heinz D.; Outeiro, Tiago F.; Park, Hay-Oak; Pendl, Tobias; Petranovic, Dina; Picot, Stephane; Polčic, Peter; Powers, Ted; Ramsdale, Mark; Rinnerthaler, Mark; Rockenfeller, Patrick; Ruckenstuhl, Christoph; Schaffrath, Raffael; Segovia, Maria; Severin, Fedor F.; Sharon, Amir; Sigrist, Stephan J.; Sommer-Ruck, Cornelia; Sousa, Maria João; Thevelein, Johan M.; Thevissen, Karin; Titorenko, Vladimir; Toledano, Michel B.; Tuite, Mick; Vögtle, F.-Nora; Westermann, Benedikt; Winderickx, Joris; Wissing, Silke; Wölfl, Stefan; Zhang, Zhaojie J.; Zhao, Richard Y.; Zhou, Bing; Galluzzi, Lorenzo; Kroemer, Guido; Madeo, Frank

2018-01-01

Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic cell death, as we refer to additional cell death routines that are relevant for the biology of (at least some species of) yeast. As this area of investigation advances rapidly, changes and extensions to this set of recommendations will be implemented in the years to come. Nonetheless, we strongly encourage the authors, reviewers and editors of scientific articles to adopt these collective standards in order to establish an accurate framework for yeast cell death research and, ultimately, to accelerate the progress of this vibrant field of research. PMID:29354647

Applications of yeast surface display for protein engineering

PubMed Central

Cherf, Gerald M.; Cochran, Jennifer R.

2015-01-01

The method of displaying recombinant proteins on the surface of Saccharomyces cerevisiae via genetic fusion to an abundant cell wall protein, a technology known as yeast surface display, or simply, yeast display, has become a valuable protein engineering tool for a broad spectrum of biotechnology and biomedical applications. This review focuses on the use of yeast display for engineering protein affinity, stability, and enzymatic activity. Strategies and examples for each protein engineering goal are discussed. Additional applications of yeast display are also briefly presented, including protein epitope mapping, identification of protein-protein interactions, and uses of displayed proteins in industry and medicine. PMID:26060074

The primary structures of two yeast enolase genes. Homology between the 5' noncoding flanking regions of yeast enolase and glyceraldehyde-3-phosphate dehydrogenase genes.

PubMed

Holland, M J; Holland, J P; Thill, G P; Jackson, K A

1981-02-10

Segments of yeast genomic DNA containing two enolase structural genes have been isolated by subculture cloning procedures using a cDNA hybridization probe synthesized from purified yeast enolase mRNA. Based on restriction endonuclease and transcriptional maps of these two segments of yeast DNA, each hybrid plasmid contains a region of extensive nucleotide sequence homology which forms hybrids with the cDNA probe. The DNA sequences which flank this homologous region in the two hybrid plasmids are nonhomologous indicating that these sequences are nontandemly repeated in the yeast genome. The complete nucleotide sequence of the coding as well as the flanking noncoding regions of these genes has been determined. The amino acid sequence predicted from one reading frame of both structural genes is extremely similar to that determined for yeast enolase (Chin, C. C. Q., Brewer, J. M., Eckard, E., and Wold, F. (1981) J. Biol. Chem. 256, 1370-1376), confirming that these isolated structural genes encode yeast enolase. The nucleotide sequences of the coding regions of the genes are approximately 95% homologous, and neither gene contains an intervening sequence. Codon utilization in the enolase genes follows the same biased pattern previously described for two yeast glyceraldehyde-3-phosphate dehydrogenase structural genes (Holland, J. P., and Holland, M. J. (1980) J. Biol. Chem. 255, 2596-2605). DNA blotting analysis confirmed that the isolated segments of yeast DNA are colinear with yeast genomic DNA and that there are two nontandemly repeated enolase genes per haploid yeast genome. The noncoding portions of the two enolase genes adjacent to the initiation and termination codons are approximately 70% homologous and contain sequences thought to be involved in the synthesis and processing messenger RNA. Finally there are regions of extensive homology between the two enolase structural genes and two yeast glyceraldehyde-3-phosphate dehydrogenase structural genes within the 5

[The yeast biofilm in human medicine].

PubMed

Růzicka, Filip; Holá, Veronika; Votava, Miroslav

2007-08-01

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

Heavy metal removal by caustic-treated yeast immobilized in alginate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Y.; Wilkins, E.

1995-12-31

Saccharomyces cerevisiae yeast biomass was treated with hot alkali to increase its biosorption capacity for heavy metals and then was immobilized in alginate gel. Biosorption capacities for Cu{sup 2+}, Cd{sup 2+}, and Zn{sup 2+} on alginate gel, native yeast, native yeast immobilized in alginate gel, and caustic-treated yeast immobilized in alginate gel were all compared. Immobilized yeasts could be reactivated and reused in a manner similar to the ion exchange resins. Immobilized caustic-treated yeast has high heavy metal biosorption capacity and high metal removal efficiency in a rather wide acidic pH region. The biosorption isotherm of immobilized caustic-treated yeast wasmore » studied, and empirical equations were obtained. The initial pH of polluted water affected the metal removal efficiency significantly, and the equilibrium biosorption capacity seemed to be temperature independent at lower initial metal concentrations.« less

A Proteome-wide Fission Yeast Interactome Reveals Network Evolution Principles from Yeasts to Human.

PubMed

Vo, Tommy V; Das, Jishnu; Meyer, Michael J; Cordero, Nicolas A; Akturk, Nurten; Wei, Xiaomu; Fair, Benjamin J; Degatano, Andrew G; Fragoza, Robert; Liu, Lisa G; Matsuyama, Akihisa; Trickey, Michelle; Horibata, Sachi; Grimson, Andrew; Yamano, Hiroyuki; Yoshida, Minoru; Roth, Frederick P; Pleiss, Jeffrey A; Xia, Yu; Yu, Haiyuan

2016-01-14

Here, we present FissionNet, a proteome-wide binary protein interactome for S. pombe, comprising 2,278 high-quality interactions, of which ∼ 50% were previously not reported in any species. FissionNet unravels previously unreported interactions implicated in processes such as gene silencing and pre-mRNA splicing. We developed a rigorous network comparison framework that accounts for assay sensitivity and specificity, revealing extensive species-specific network rewiring between fission yeast, budding yeast, and human. Surprisingly, although genes are better conserved between the yeasts, S. pombe interactions are significantly better conserved in human than in S. cerevisiae. Our framework also reveals that different modes of gene duplication influence the extent to which paralogous proteins are functionally repurposed. Finally, cross-species interactome mapping demonstrates that coevolution of interacting proteins is remarkably prevalent, a result with important implications for studying human disease in model organisms. Overall, FissionNet is a valuable resource for understanding protein functions and their evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

Actin and Endocytosis in Budding Yeast

PubMed Central

Goode, Bruce L.; Eskin, Julian A.; Wendland, Beverly

2015-01-01

Endocytosis, the process whereby the plasma membrane invaginates to form vesicles, is essential for bringing many substances into the cell and for membrane turnover. The mechanism driving clathrin-mediated endocytosis (CME) involves > 50 different protein components assembling at a single location on the plasma membrane in a temporally ordered and hierarchal pathway. These proteins perform precisely choreographed steps that promote receptor recognition and clustering, membrane remodeling, and force-generating actin-filament assembly and turnover to drive membrane invagination and vesicle scission. Many critical aspects of the CME mechanism are conserved from yeast to mammals and were first elucidated in yeast, demonstrating that it is a powerful system for studying endocytosis. In this review, we describe our current mechanistic understanding of each step in the process of yeast CME, and the essential roles played by actin polymerization at these sites, while providing a historical perspective of how the landscape has changed since the preceding version of the YeastBook was published 17 years ago (1997). Finally, we discuss the key unresolved issues and where future studies might be headed. PMID:25657349

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

PubMed Central

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

2008-01-01

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

[Malassezia yeasts and their significance in dermatology].

PubMed

Hort, W; Nilles, M; Mayser, P

2006-07-01

Yeasts of the genus Malassezia belong to the normal microflora of the human skin. In addition they are known to cause a variety of skin diseases; the most frequent of which is pityriasis versicolor. Malassezia yeasts are also thought to be associated with seborrheic dermatitis, dandruff and Malassezia folliculitis. Recently the significance of Malassezia yeasts as a trigger factor for atopic dermatitis of the head and neck region has been pointed out. The role of the Malassezia yeasts in these different diseases has been controversial in the past and remains an issue because of difficulties in isolation, culture and differentiation of the organism. Thanks to molecular techniques, 10 species can actually be differentiated. The article presents the different Malassezia-associated diseases, their clinical picture, diagnosis and appropriate therapy. In addition the speciation of Malassezia is reviewed.

Yeast as a tool to identify anti-aging compounds

PubMed Central

Zimmermann, Andreas; Hofer, Sebastian; Pendl, Tobias; Kainz, Katharina; Madeo, Frank; Carmona-Gutierrez, Didac

2018-01-01

Abstract In the search for interventions against aging and age-related diseases, biological screening platforms are indispensable tools to identify anti-aging compounds among large substance libraries. The budding yeast, Saccharomyces cerevisiae, has emerged as a powerful chemical and genetic screening platform, as it combines a rapid workflow with experimental amenability and the availability of a wide range of genetic mutant libraries. Given the amount of conserved genes and aging mechanisms between yeast and human, testing candidate anti-aging substances in yeast gene-deletion or overexpression collections, or de novo derived mutants, has proven highly successful in finding potential molecular targets. Yeast-based studies, for example, have led to the discovery of the polyphenol resveratrol and the natural polyamine spermidine as potential anti-aging agents. Here, we present strategies for pharmacological anti-aging screens in yeast, discuss common pitfalls and summarize studies that have used yeast for drug discovery and target identification. PMID:29905792

Yeast Genomics for Bread, Beer, Biology, Bucks and Breath

NASA Astrophysics Data System (ADS)

Sakharkar, Kishore R.; Sakharkar, Meena K.

The rapid advances and scale up of projects in DNA sequencing dur ing the past two decades have produced complete genome sequences of several eukaryotic species. The versatile genetic malleability of the yeast, and the high degree of conservation between its cellular processes and those of human cells have made it a model of choice for pioneering research in molecular and cell biology. The complete sequence of yeast genome has proven to be extremely useful as a reference towards the sequences of human and for providing systems to explore key gene functions. Yeast has been a ‘legendary model’ for new technologies and gaining new biological insights into basic biological sciences and biotechnology. This chapter describes the awesome power of yeast genetics, genomics and proteomics in understanding of biological function. The applications of yeast as a screening tool to the field of drug discovery and development are highlighted and the traditional importance of yeast for bakers and brewers is discussed.

[Treatment of oil-manufacturing wastewater by yeast-SBR system].

PubMed

Lü, Wen-zhou; Liu, Ying; Huang, Yi-zhen

2008-04-01

Eight yeast strains were applied to a sequencing batch reactor (SBR) to treat high-strength oil-containing wastewater. The removal performance, yeast cultivation method and key factors affecting the stability of system were discussed. The results show yeast sludge with MLSS of 19 g/L and SVI of 35 mL/g can be obtained in 6 d in an open system without any molds and bacteria inhibitor addition; In 30 d continuous wastewater treatment, COD and oil removal rate achieve 86.8%-96.9% and above 99.5% respectively under the influent conditions of the COD of 9000-23000 mg/L and oil of 4500-16000 mg/L; Short period of pH impact brings reversible effects on the system and the sludge retention time can affect the SVI of the yeast; Absence of nitrogen induces morphology conversion of some yeast cells from single cell to filamentous one and impairs the settling capability of the yeast.

The Yeast Deletion Collection: A Decade of Functional Genomics

PubMed Central

Giaever, Guri; Nislow, Corey

2014-01-01

The yeast deletion collections comprise >21,000 mutant strains that carry precise start-to-stop deletions of ∼6000 open reading frames. This collection includes heterozygous and homozygous diploids, and haploids of both MATa and MATα mating types. The yeast deletion collection, or yeast knockout (YKO) set, represents the first and only complete, systematically constructed deletion collection available for any organism. Conceived during the Saccharomyces cerevisiae sequencing project, work on the project began in 1998 and was completed in 2002. The YKO strains have been used in numerous laboratories in >1000 genome-wide screens. This landmark genome project has inspired development of numerous genome-wide technologies in organisms from yeast to man. Notable spinoff technologies include synthetic genetic array and HIPHOP chemogenomics. In this retrospective, we briefly describe the yeast deletion project and some of its most noteworthy biological contributions and the impact that these collections have had on the yeast research community and on genomics in general. PMID:24939991

Commercial Bee Pollen with Different Geographical Origins: A Comprehensive Approach

PubMed Central

Nogueira, Carla; Iglesias, Antonio; Feás, Xesus; Estevinho, Leticia M.

2012-01-01

Since the primordial of humanity, pollen has been considered a good source of nutrients and energy. Its promising healing properties have also been referred to. The present study aimed to characterize, for the first time, eight commercial pollens from Portugal and Spain available on the market studying the legislation on labeling, pollinic origin, physicochemical and microbiological analyses and identification of yeasts. Eleven botanical families were found amongst the samples. The most abundant family and the most dominant pollen was Cistaceae. The moisture content, ash, aw, pH, reducing sugars, carbohydrates, proteins, lipids and energy were analyzed and the specific parameters were within the specifications required by some countries with legislation regarding these parameters. Microbiologically commercial pollen showed acceptable safety for the commercial quality and hygiene. All samples showed negative results for toxigenic species. The microorganisms studied were aerobic mesophiles, yeasts and moulds, coliforms, Escherichia coli, Staphylococcus aureus, Salmonella and sulfite-reducing Clostridium. During the work, six yeasts species were isolated from pollen, with Rhodotorula mucilaginosa being the most abundant, as it was present in four samples. PMID:23109845