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1.
Mol Biol Rep ; 47(11): 8903-8909, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33130966

RESUMO

Luliconazole is an imidazole antifungal agent used in topical form for the treatment of onychomycosis and dermatophytosis. In vitro activity of luliconazole against dermatophytes, Candida, black fungi, Fusarium and Aspergillus species have been investigated. Rhodotorula spp. are environmental yeasts and emerged as opportunistic pathogens among immunocompromised patients. Rhodotorula's human infections are usually resistant to treatment with antifungal drugs especially triazoles and echinocandins. The present study aimed at the molecular detection of environmental isolates of Rhodotorula spp. Then, antifungal efficacy of luliconazole was evaluated against isolates and compared to other routine systemic antifungals including; caspofungin, posaconazole, fluconazole, itraconazole, amphotericin B, and voriconazole. The biofilm production of Rhodotorula isolates was also evaluated. In this study, 39 isolates of Rhodotorula spp. were isolated from the environment, detected using molecular methods, and tested against luliconazole. Then, the anti-fungal activity of luliconazole compared with several routine antifungals. Also, biofilm formation by using a crystal violet staining assay was performed. Our finding showed that luliconazole has a very high minimum inhibitory concentration (MIC) value (1-8 µg/ml) against Rhodotorula spp. Besides, 100% of Rhodotorula strains were resistant to caspofungin, followed by fluconazole 94.7% and voriconazole 74.4%. Amphotericin B was demonstrated excellent in vitro activity against this genus. Our result indicated that 59% of Rhodotorula spp. were in the mid-range of biofilm production. Our results indicated that luliconazole does not effective against the genus Rhodotorula. Furthermore, amphotericin B is the best drug against this genus in comparison to caspofungin and other azole drugs.


Assuntos
Biofilmes/efeitos dos fármacos , Imidazóis/farmacologia , Testes de Sensibilidade Microbiana/métodos , Rhodotorula/efeitos dos fármacos , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Biofilmes/crescimento & desenvolvimento , Caspofungina/farmacologia , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Fluconazol/farmacologia , Humanos , Itraconazol/farmacologia , Filogenia , Rhodotorula/classificação , Rhodotorula/fisiologia , Especificidade da Espécie , Triazóis/farmacologia , Voriconazol/farmacologia
2.
Ecotoxicol Environ Saf ; 194: 110441, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32155484

RESUMO

Vesicles (Ves) within fungal cells are the critical linkage between intracellular and extracellular systems. This study explored the application of Pb2+ to probe the physiology of intracellular Ves in Rhodotorula mucilaginosa (Rho). At low Pb2+ levels (0-500 mg/L), there was no evident change in the content of extracellular polymeric substances (EPS) or microbial activity. At medium-high levels (1000-2000 mg/L), the sizes of Ves within the Rho cells were significantly enlarged, with abundant lead nano-particles (Pb NPs) formed either on the cell surface or interior, whereas the EPS content and bioactivity were still stable. At a high level (2500 mg/L), the Rho cells were severely deformed, with cell counts reduced by more than 99%. However, the EPS contents and the respiration rate of the surviving cells dramatically increased to the maximum values (i.e., 1785 mg/1010 cells and 37 mg C 10-10 cells h-1, respectively). The Ves surface adsorbed Pb cations with higher density, compared with the cell membrane. Moreover, fusion of some Ves to the membrane (functioning in transport) was observed under transmission electron microscope (TEM). Three pathways of detoxification via intracellular Ves were finally proposed, i.e., Ve-mediated transport (from intracellular to extracellular) of EPS components, absorption of Pb NPs on the Ve surface, and accumulation of Pb NPs within Ves. This study sheds light on the possibility of exploring microbial physiology via Pb2+ cations.


Assuntos
Substâncias Perigosas/toxicidade , Chumbo/toxicidade , Rhodotorula/fisiologia , Adsorção , Cátions , Testes de Toxicidade
3.
J Appl Microbiol ; 127(4): 1069-1079, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31237965

RESUMO

AIMS: To evaluate an aqueous extract of Macrocystis pyrifera as a nutrient source for the production of carotenoids by a marine Rhodotorula mucilaginosa isolated from seaweed samples. MATERIALS AND RESULTS: The effect of different culture conditions on the concentration of biomass and total pigments was evaluated using a Box-Behnken experimental design. The seaweed extract contained 15% w w-1 of protein and 20% w w-1 of carbohydrate; the main sugar in this fraction was trehalose (78%). The culture conditions that maximize the total pigment concentration (1·84 ± 0·03 mg l-1 ) were initial pH equal to 7, yeast extract as nitrogen source at a concentration of 4 g l-1 , seaweed extract concentration at 25% v v-1 , incubation performed at 25°C and 150 rev min-1 during 6 days. Under optimal growth conditions, three carotenoids were identified among the pigments produced by R. mucilaginosa, lycopene (38·4 ± 9·4%), ß-carotene (21·8 ± 1·5%) and astaxanthin (1·8 ± 0·3%). CONCLUSIONS: Carotenoids of commercial interest (lycopene, ß-carotene and astaxanthin) can be produced using a marine R. mucilaginosa cultivated with an aqueous extract of M. pyrifera as nutrient source. The total pigment concentration in the culture ranged between 0·82 and 1·84 mg l-1 , and was significantly affected by the concentration of the seaweed extract, and yeast extract. SIGNIFICANCE AND IMPACT OF THE STUDY: This work demonstrates that M. pyrifera can be used as a nutrient source for the production of carotenoids by the marine yeast.


Assuntos
Carotenoides , Macrocystis/química , Rhodotorula , Biomassa , Reatores Biológicos , Carotenoides/análise , Carotenoides/metabolismo , Meios de Cultura , Rhodotorula/metabolismo , Rhodotorula/fisiologia
4.
J Basic Microbiol ; 59(9): 879-889, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31339587

RESUMO

Metallothionein (MT) is a low-molecular-weight protein with a high metal binding capacity and plays a key role in organism adaptation to heavy metals. In this study, a metallothionein gene was successfully cloned and sequenced from Antarctic sea-ice yeast Rhodotorula mucilaginosa AN5. Nucleotide sequencing and analysis revealed that the gene had four exons interrupted by three introns. MTs complementary DNA (named as RmMT) had an open reading frame of 321 bp encoding a 106 amino acid protein with a predicted molecular weight of 10.3 kDa and pI of 8.49. The number of amino acids and distribution of cysteine residues indicated that RmMT was a novel family of fungal MTs. Quantitative real-time polymerase chain reaction analysis showed that RmMT expression was elevated under copper-induced stress. The RmMT gene was transferred into E. coli and the RmMT expressing bacteria showed improved tolerance to copper ion and increased accumulation of heavy metals, such as Cu2+ , Pb2+ , Zn2+ , Cd2+ , and Ag+ . Moreover, in vitro studies, purified recombinant RmMT demonstrated that it could be used as a good scavenger of superoxide anion, hydroxyl, and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radicals. In summary, these results demonstrate that RmMT plays a key role in the tolerance and bioaccumulation of heavy metals.


Assuntos
Camada de Gelo/microbiologia , Metalotioneína/genética , Metalotioneína/metabolismo , Metais Pesados/metabolismo , Rhodotorula/genética , Adaptação Fisiológica/genética , Regiões Antárticas , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Sequência de Bases , Clonagem Molecular , Cobre/metabolismo , Escherichia coli/genética , Escherichia coli/fisiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Expressão Gênica , Metalotioneína/isolamento & purificação , Fases de Leitura Aberta , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Rhodotorula/fisiologia
5.
Fish Physiol Biochem ; 45(2): 511-521, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30519984

RESUMO

Defense mechanisms of fish are investigated in many aspects. One of the most interesting systems is that based on non-specific immune factors whose mechanisms of biocontrol have evolved in complex processes of microbiological co-existence. The wild fish devoid of probiotic stimulation have developed their own system to control the biosynthesis of immunostimulating compounds based on commensal microflora. Results of this study demonstrated the gastrointestinal tract (GI) of wild fish (Abramis brama, Rutilus rutilus, Perca fluviatilis) was colonized by permanently residing strains of Rhodotorula mucilaginosa. The genetic profile of the tested strains (PCR-random amplification of polymorphic DNA) indicated their affinity only to the GI of the analyzed fish. The capability for biosynthesis of ß-carotene, torulene, torularhodin, and exopolysaccharides (EPS) under conditions of fish gastrointestinal tract was found to be a strain-specific trait. Rhodotorula spp. interactions with fish should be considered as a mechanism of symbiotic relations based on the stimulation of non-specific mechanisms of fish immunoprotection and antioxidative properties of yeast.


Assuntos
Peixes/microbiologia , Peixes/fisiologia , Trato Gastrointestinal/microbiologia , Rhodotorula/fisiologia , Animais , Combinação Budesonida e Fumarato de Formoterol , Variação Genética , Rhodotorula/genética
6.
Water Sci Technol ; 76(3-4): 806-812, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28799927

RESUMO

The aim of the study was to examine heavy metal tolerance (Cd2+, Zn2+, Ni2+ and Cu2+) of single- and mixed-species biofilms (Rhodotorula mucilaginosa and Escherichia coli) and to determine metal removal efficiency (Cd2+, Zn2+, Ni2+, Cu2+, Pb2+ and Hg2+). Metal tolerance was quantified by crystal violet assay and results were confirmed by fluorescence microscopy. Metal removal efficiency was determined by batch biosorption assay. The tolerance of the mixed-species biofilm was higher than the single-species biofilms. Single- and mixed-species biofilms showed the highest sensitivity in the presence of Cu2+ (E. coli-MIC 4 mg/ml, R. mucilaginosa-MIC 8 mg/ml, R. mucilaginosa/E. coli-MIC 64 mg/ml), while the highest tolerance was observed in the presence of Zn2+ (E. coli-MIC 80 mg/ml, R. mucilaginosa-MIC 161 mg/ml, R. mucilaginosa-E. coli-MIC 322 mg/ml). The mixed-species biofilm exhibited better efficiency in removal of all tested metals than single-species biofilms. The highest efficiency in Cd2+ removal was shown by the E. coli biofilm (94.85%) and R. mucilaginosa biofilm (97.85%), individually. The highest efficiency in Cu2+ (99.88%), Zn2+ (99.26%) and Pb2+ (99.52%) removal was shown by the mixed-species biofilm. Metal removal efficiency was in the range of 81.56%-97.85% for the single- and 94.99%-99.88% for the mixed-species biofilm.


Assuntos
Biofilmes/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Rhodotorula/efeitos dos fármacos , Escherichia coli/fisiologia , Rhodotorula/fisiologia
7.
Yeast ; 32(11): 683-90, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26284451

RESUMO

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.


Assuntos
Adaptação Fisiológica/fisiologia , Ácidos Graxos Insaturados/metabolismo , Rhodotorula/fisiologia , Sequência de Aminoácidos , Membrana Celular/fisiologia , Clonagem Molecular , Temperatura Baixa , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Insaturados/genética , Expressão Gênica , Ácido Linoleico/metabolismo , Fluidez de Membrana/fisiologia , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Rhodotorula/genética , Rhodotorula/crescimento & desenvolvimento , Rhodotorula/metabolismo , Saccharomyces cerevisiae/genética , Ácido alfa-Linolênico/metabolismo
8.
Can J Microbiol ; 61(10): 763-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26308797

RESUMO

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.


Assuntos
Microbiota , Trichechus/microbiologia , Animais , Brasil , Candida/isolamento & purificação , Candida/fisiologia , Cryptococcus/isolamento & purificação , Cryptococcus/fisiologia , Feminino , Masculino , Rhodotorula/isolamento & purificação , Rhodotorula/fisiologia , Trichechus inunguis/microbiologia , Trichechus manatus/microbiologia , Trichosporon/isolamento & purificação , Trichosporon/fisiologia
9.
J Basic Microbiol ; 55(8): 1029-39, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25727311

RESUMO

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.


Assuntos
6-Fitase/isolamento & purificação , 6-Fitase/metabolismo , Adaptação Fisiológica , Temperatura Baixa , Sedimentos Geológicos/microbiologia , Rhodotorula/enzimologia , 6-Fitase/antagonistas & inibidores , 6-Fitase/química , Sequência de Aminoácidos , Regiões Antárticas , Aquicultura , Estabilidade Enzimática , Fermentação , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Pepsina A/metabolismo , Filogenia , Rhodotorula/isolamento & purificação , Rhodotorula/fisiologia , Especificidade por Substrato , Tripsina/metabolismo
10.
J Periodontal Res ; 48(4): 428-32, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23137301

RESUMO

BACKGROUND AND OBJECTIVE: The aim of this study is to analyze the relationship between the subgingival colonization by Candida albicans and other yeasts with the severity of chronic periodontitis (CP). MATERIAL AND METHODS: After sample size calculation, 40 patients with CP and 20 healthy subjects (HS) were included in the study. Cases of slight-moderate (MCP, n = 23) and severe CP (SCP, n = 17) were defined according to the Centers for Disease Control/American Association of Periodontology classification. Subgingival samples were acquired using sterile paper-points from the sulcus or the deepest periodontal pocket of each healthy and subject with CP, respectively, and were cultured aerobically on three selective media. Yeast colonies that grew on the surface of plates were later identified by biochemical reactions. Statistical tests were used to analyze the association between subgingival yeast colonization (number of yeast-positive individuals and colony forming units (CFU) per subject) and periodontal disease status, considering statistical significance when P < 0.05. RESULTS: Although several yeast species were found (C. parapisilosis, Rhodotorula sp., C. dubliniensis and C. tropicalis), only C. albicans was present in all the patients with yeast-positive CP. Twelve patients (30%) with CP presented yeasts in the subgingival biofilm while only three patients (15%) in the HS group were positive for these microorganisms. No statistical difference was found between the CP and HS groups (P = 0.084). However, when the CP group was divided on the basis of severity, statistical differences were observed between the SCP and MCP groups (47% vs. 17%, P = 0.043), and between the SCP and HS groups (47% vs. 15%, P = 0.033). No statistical difference was observed between the MCP and HS groups (17% vs. 15%, P = 0.832). High densities of yeasts were found only in patients with MCP and SCP (mean and range 61.25 (0-100) CFU/plate and mean and range 51 (0-101) CFU/plate, respectively). CONCLUSION: In this group of patients, subgingival colonization of some yeasts, especially C. albicans, was associated with the severity of CP.


Assuntos
Candida albicans/fisiologia , Periodontite Crônica/microbiologia , Gengiva/microbiologia , Rhodotorula/fisiologia , Adulto , Idoso , Biofilmes , Candida/classificação , Candida/fisiologia , Candida tropicalis/fisiologia , Candidíase Bucal/microbiologia , Estudos de Casos e Controles , Periodontite Crônica/classificação , Contagem de Colônia Microbiana , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Bolsa Periodontal/microbiologia , Periodonto/microbiologia , Adulto Jovem
11.
J Bioenerg Biomembr ; 44(5): 559-69, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22810564

RESUMO

The fluorescent dye 3,3'-dipropylthiadicarbocyanine, diS-C(3)(3), is a suitable probe to monitor real changes of plasma membrane potential in yeast cells which are too small for direct membrane potential measurements with microelectrodes. A method presented in this paper makes it possible to convert changes of equilibrium diS-C(3)(3) fluorescence spectra, measured in yeast cell suspensions under certain defined conditions, into underlying membrane potential differences, scaled in the units of millivolts. Spectral analysis of synchronously scanned diS-C(3)(3) fluorescence allows to assess the amount of dye accumulated in cells without otherwise necessary sample taking and following separation of cells from the medium. Moreover, membrane potential changes can be quantified without demanding calibration protocols. The applicability of this approach was demonstrated on the depolarization of Rhodotorula glutinis yeast cells upon acidification of cell suspensions and/or by increasing extracellular K(+) concentration.


Assuntos
Carbocianinas/química , Corantes Fluorescentes/química , Potenciais da Membrana/fisiologia , Rhodotorula/fisiologia , Rhodotorula/citologia
12.
J Basic Microbiol ; 52(5): 573-81, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22144174

RESUMO

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.


Assuntos
Acrilamida/metabolismo , Rhodotorula/isolamento & purificação , Rhodotorula/fisiologia , Acrilatos/metabolismo , Biotransformação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Concentração de Íons de Hidrogênio , Metais Pesados/toxicidade , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , Filogenia , Rhodotorula/classificação , Rhodotorula/genética , Análise de Sequência de DNA , Temperatura , Fatores de Tempo
14.
Biofouling ; 27(9): 979-91, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21981116

RESUMO

Yeast biofilms contribute to quality impairment of industrial processes and also play an important role in clinical infections. Little is known about biofilm formation and their treatment. The aim of this study was to establish a multi-layer yeast biofilm model using a modified 3.7 l bench-top bioreactor operated in continuous mode (D = 0.12 h(-1)). The repeatability of biofilm formation was tested by comparing five bioprocesses with Rhodotorula mucilaginosa, a strain isolated from washing machines. The amount of biofilm formed after 6 days post inoculation was 83 µg cm(-2) protein, 197 µg cm(-2) polysaccharide and 6.9 × 10(6) CFU cm(-2) on smooth polypropylene surfaces. Roughening the surface doubled the amount of biofilm but also increased its spatial variability. Plasma modification of polypropylene significantly reduced the hydrophobicity but did not enhance cell attachment. The biofilm formed on polypropylene coupons could be used for sanitation studies.


Assuntos
Biofilmes , Reatores Biológicos/microbiologia , Rhodotorula/fisiologia , Adesão Celular , Interações Hidrofóbicas e Hidrofílicas , Reprodutibilidade dos Testes , Propriedades de Superfície
15.
Appl Microbiol Biotechnol ; 86(6): 1933-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20180117

RESUMO

To investigate the effects of physiological properties on polycyclic aromatic compound (PAH) degradation, the surface tension and emulsification activities, and cell surface hydrophobicity of five PAH-degrading yeast isolates were compared to Saccharomyces cerevisiae from cultures grown with glucose, hexadecane, or naphthalene as carbon sources. The cell surface hydrophobicity values for the five yeast strains were significantly higher than for S. cerevisiae for all culture conditions, although these were highest with hexadecane and naphthalene. Strains with higher hydrophobicity showed higher rates of naphthalene and phenanthrene degradation, indicating that increased cell hydrophobicity might be an important strategy in PAH degradation for the five strains. Emulsification activities increased for all five yeast strains with naphthalene culturing, although no relationship existed between emulsification activity and PAH degradation rate. Surface tensions were not markedly reduced with naphthalene culturing.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Leveduras/fisiologia , Alcanos/metabolismo , Basidiomycota/metabolismo , Basidiomycota/fisiologia , Biodegradação Ambiental , Candida/metabolismo , Candida/fisiologia , Interações Hidrofóbicas e Hidrofílicas , Naftalenos/metabolismo , Fenantrenos/metabolismo , Pichia/metabolismo , Pichia/fisiologia , Rhodotorula/metabolismo , Rhodotorula/fisiologia , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Especificidade da Espécie , Propriedades de Superfície , Tensão Superficial , Leveduras/metabolismo
16.
Extremophiles ; 13(2): 257-62, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19057843

RESUMO

Three bacterial (Pedobacter heparinus, Pedobacter piscium, Pedobacter cryoconitis) and three yeast strains (Saccharomyces cerevisiae, Leucosporidiella creatinivora, Rhodotorula glacialis) of different thermal classes (mesophiles and psychrophiles) were tested for the effect of temperature on a range of growth parameters, including optical density, viable cell numbers, and cell dry mass, in order to determine the temperature conditions under which maximum biomass formation is obtained. Maximum values of growth parameters obtained at the stationary growth phase of the strains were used for statistical calculation. Temperature had a significant (P

Assuntos
Bactérias/crescimento & desenvolvimento , Basidiomycota/fisiologia , Rhodotorula/fisiologia , Saccharomyces cerevisiae/fisiologia , Leveduras/fisiologia , Adaptação Fisiológica , Fenômenos Fisiológicos Bacterianos , Basidiomycota/crescimento & desenvolvimento , Biomassa , Temperatura Baixa , Contagem de Colônia Microbiana , Concentração de Íons de Hidrogênio , Modelos Estatísticos , Rhodotorula/crescimento & desenvolvimento , Saccharomyces cerevisiae/crescimento & desenvolvimento , Especificidade da Espécie , Temperatura , Leveduras/crescimento & desenvolvimento
17.
Int J Biol Macromol ; 121: 55-62, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30290257

RESUMO

The capability of plant growth promoting microbes to survive under abiotic stresses has important significance for improving plant growth and productivity. Among the various plant growth promoting biomolecules produced by microbes, exopolysaccharide (EPS) help microbes to survive in inhospitable environments and endure environmental stressful conditions. In the present study, a yeast strain CAH2 was isolated from Beta vulgaris rhizosphere soil and identified as Rhodotorula sp., based on the partial 18S rRNA gene sequence analysis. Rhodotorula sp. strain CAH2 was found to tolerate higher concentrations of Al (6 mM), NaCl (150 mM) and PEG-6000 (15%, w/v). The strain CAH2 was shown to produce 7.5 g L-1 of EPS in the production medium with sucrose and yeast extract as a carbon and nitrogen sources, respectively. The EPS yield was increased constantly with increasing concentrations of Al, NaCl and PEG-6000. The structural feature of EPS studied through FT-IR and NMR spectral analysis confirmed the presence of glucose, mannose and galactose. The yeast strain CAH2 was produced multiple plant growth promoting traits in the presence and absence of abiotic stresses. Finally, these results indicate that the production of EPS could be safeguard the plant growth promoting Rhodotorula sp. strain CAH2 from unfavourable environmental conditions.


Assuntos
Polissacarídeos Fúngicos/biossíntese , Desenvolvimento Vegetal , Plantas/microbiologia , Rhodotorula/fisiologia , Estresse Fisiológico , Polissacarídeos Fúngicos/química , Rhodotorula/metabolismo
18.
DNA Res ; 26(2): 131-146, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30615101

RESUMO

Endophytic yeasts of genus Rhodotorula are gaining importance for their ability to improve plant growth. The nature of their interaction with plants, however, remains unknown. Rhodotorula mucilaginosa JGTA-S1 was isolated as an endophyte of Typha angustifolia and promoted growth in the host. To investigate the life-strategy of the yeast from a genomics perspective, we used Illumina and Oxford Nanopore reads to generate a high-quality annotated draft assembly of JGTA-S1 and compared its genome to three other Rhodotorula yeasts and the close relative Rhodosporidium toruloides. JGTA-S1 is a haploid yeast possessing several genes potentially facilitating its endophytic lifestyle such as those responsible for solubilizing phosphate and producing phytohormones. An intact mating-locus in JGTA-S1 raised the possibility of a yet unknown sexual reproductive cycle in Rhodotorula yeasts. Additionally, JGTA-S1 had functional anti-freezing genes and was also unique in lacking a functional nitrate-assimilation pathway-a feature that is associated with obligate biotrophs. Nitrogen-fixing endobacteria were found within JGTA-S1 that may circumvent this defective N-metabolism. JGTA-S1 genome data coupled with experimental evidence give us an insight into the nature of its beneficial interaction with plants.


Assuntos
Endófitos , Genoma Fúngico , Redes e Vias Metabólicas , Rhodotorula/genética , Simbiose , Bactérias/metabolismo , Genômica , Nitrogênio/metabolismo , Pseudomonas stutzeri/metabolismo , Rhodotorula/metabolismo , Rhodotorula/fisiologia , Análise de Sequência de DNA , Typhaceae
19.
Int J Food Microbiol ; 126(1-2): 167-71, 2008 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18579245

RESUMO

Rhodotorula glutinis was evaluated for its activity in reducing postharvest gray mold decay and blue mold decay of pear caused by Botrytis cinerea and Penicillium expansum respectively, and in reducing natural decay development of pear fruits, as well as its effects on postharvest quality of fruits. There was a significant negative correlation between concentrations of the yeast cells and infectivity of the pathogens. At concentrations of R. glutinis at 5x108 CFU/ml, the gray mold decay was completely inhibited after 7 days incubation at 20 degrees C, while the control fruit had 100% disease incidence and 2.15 cm lesion diameter respectively, at challenged with B. cinerea spores suspension of 1x105 spores/ml; No completely control was got to blue mold, when pear fruits stored at 20 degrees C for 7 d (challenged with P. expansum spores suspension of 5x104 spores/ml), but the decay was distinctly prevented with 20% and 0.60 cm of disease incidence and lesion diameter respectively, while the control fruits were 100% and 2.74 cm, respectively. Rapid colonization of the yeast in wounds was observed during the first 1 d at 20 degrees C, and then the populations stabilized for the remaining storage period. On pear wounds kept at 4 degrees C, rapid colonization of the yeast in wounds was observed during the first 3 d, and then the increase in population density of R. glutinis turned slow, which continued over 6 d after application of the antagonist until it reached a high level. Then, the populations stabilized for the remaining storage period. In the test on PDA plates, R. glutinis significantly inhibit the growth of B. cinerea and P. expansum. Spore germination of pathogens in PDB was greatly controlled in the present of living yeast cell suspensions. R. glutinis significantly reduced the natural development of decay of pear following storage at 20 degrees C for 7 days or at 4 degrees C for 30 days followed by 20 degrees C for 5 days, and did not impair quality parameters, including mass loss, firmness, TSS, ascorbic acid or titratable acidity. Thus, the application of R. glutinis can be an alternative to chemicals for control of postharvest diseases on pear fruits.


Assuntos
Botrytis/crescimento & desenvolvimento , Conservação de Alimentos/métodos , Penicillium/crescimento & desenvolvimento , Controle Biológico de Vetores/métodos , Pyrus/microbiologia , Rhodotorula/fisiologia , Antibiose , Contagem de Colônia Microbiana , Temperatura , Fatores de Tempo
20.
Trends Biotechnol ; 36(3): 304-317, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29132754

RESUMO

Moving our society towards a bioeconomy requires efficient and sustainable microbial production of chemicals and fuels. Rhodotorula (Rhodosporidium) toruloides is a yeast that naturally synthesizes substantial amounts of specialty chemicals and has been recently engineered to (i) enhance its natural production of lipids and carotenoids, and (ii) produce novel industrially relevant compounds. The use of R. toruloides by companies and research groups has exponentially increased in recent years as a result of recent improvements in genetic engineering techniques and the availability of multiomics information on its genome and metabolism. This review focuses on recent engineering approaches in R. toruloides for bioproduction and explores its potential as a biotechnological chassis.


Assuntos
Biotecnologia , Engenharia Genética , Engenharia Metabólica , Rhodotorula/fisiologia , Carotenoides/biossíntese , Edição de Genes , Genoma Fúngico/genética , Genômica , Lipídeos/biossíntese , Metabolômica , Proteômica , Rhodotorula/genética
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