Advances in gene editing and natural product synthesis of Rhodotorula toruloides / 生物工程学报

Rhodotorula toruloides is a non-conventional red yeast that can synthesize various carotenoids and lipids. It can utilize a variety of cost-effective raw materials, tolerate and assimilate toxic inhibitors in lignocellulosic hydrolysate. At present, it is widely investigated for the production of microbial lipids, terpenes, high-value enzymes, sugar alcohols and polyketides. Given its broad industrial application prospects, researchers have carried out multi-dimensional theoretical and technological exploration, including research on genomics, transcriptomics, proteomics and genetic operation platform. Here we review the recent progress in metabolic engineering and natural product synthesis of R. toruloides, and prospect the challenges and possible solutions in the construction of R. toruloides cell factory.

Rhodotorula fungemia in a patient with acute lymphoblastic leukemia / Fungemia de Rhodotorula em paciente com leucemia linfoblástica aguda / Fungemia por Rhodotorula en un paciente con leucemia linfoblástica aguda

Objectives: Rhodotorula is an environmental yeast that belongs to Basidiomycota Phylum. Rhodotorula species are ubiquitous in nature, can be found in soil and freshwater. Immunocompromised patients can develop Rhodotorulosis due to wide-ranging exposure to Rhodotorula in the hospital environment. Case Discussion: The patient was a 3-year-old male with a diagnosis of Pro B-Acute Lymphoblastic Leukemia (ALL). He was admitted to the hospital with complaints of malaise, fatigue, weight loss, and diarrhea between courses of chemotherapy. Rhodotorula was isolated from the patient's blood culture obtained during the elevation of temperature. After 14 days of amphotericin B treatment, clinical situation of the patient was improved and he was discharged. Conclusion: Rhodotorula spp. as a rare yet emerging pathogen, often presents as fever of unknown etiology resistant to antibacterial treatment and can be associated with fungemia and other severe complications.(AU)

Objetivos: Rhodotorula é uma levedura ambiental que pertence ao filo Basidiomycota. As espécies de Rhodotorula são onipresentes na natureza, podem ser encontradas no solo e na água doce. Pacientes imunocomprometidos podem desenvolver rodotorulose devido à ampla exposição a Rhodotorula no ambiente hospitalar. Descrição do caso: O paciente era uma criança de 3 anos de idade com diagnóstico de Leucemia Linfoblástica Aguda Pro B (LLA). O paciente deu entrada no hospital com queixas de mal-estar, cansaço, perda de peso e diarreia entre os ciclos de quimioterapia. A Rhodotorula foi isolada da hemocultura do paciente obtida durante a elevação da temperatura. Após 14 dias de tratamento com anfotericina B, a situação clínica do paciente melhorou e o paciente recebeu alta. Conclusão: Rhodotorula spp. como um patógeno raro, porém emergente, frequentemente se apresenta como febre de etiologia desconhecida resistente ao tratamento antibacteriano e pode estar associada a fungemia e outras complicações graves.(AU)

Objetivos: Rhodotorula es una levadura ambiental que pertenece al filo Basidiomycota. Las especies de Rhodotorula son ubicuas en la naturaleza, se pueden encontrar en el suelo y en agua dulce. Los pacientes inmunodeprimidos pueden desarrollar Rhodotorulosis debido a una amplia exposición a Rhodotorula en el entorno hospitalario. Descripción del caso: El paciente era un niño de 3 años con diagnóstico de leucemia linfoblástica aguda Pro B (LLA). El paciente ingresó en el hospital con quejas de malestar, fatiga, pérdida de peso y diarrea entre ciclos de quimioterapia. Se aisló Rhodotorula del hemocultivo del paciente que se obtuvo durante la elevación de la temperatura. Después de 14 días de tratamiento con anfotericina B, la situación clínica del paciente mejoró y fue dado de alta. Conclusión: Rhodotorula spp. como patógeno poco común pero emergente, a menudo se presenta como fiebre de etiología desconocida resistente al tratamiento antibacteriano y puede asociarse con fungemia y otras complicaciones graves.(AU)

Avaliação da interação entre leveduras isoladas de kombucha e bactérias probióticas / Evaluation of the interaction between isolated kombucha yeasts and probiotic bacteria

Um dos maiores desafios no desenvolvimento de produtos probióticos é entender como os microrganismos interagem entre si e com o hospedeiro. Quando falamos em alimentos fermentados tradicionais, este obstáculo aumenta porque a matriz alimentar já possui um microbioma intrínseco. No entanto, também é conhecido que muitos microrganismos podem interagir e cooperar para sobreviver quando condições de estresse são encontradas. Assim, o objetivo deste trabalho foi isolar leveduras de quatro diferentes kombuchas em distintos momentos fermentativos e verificar a influência que leveduras isoladas de kombucha têm na manutenção da viabilidade da bactéria probiótica Bifidobacterium animalis subsp. lactis HN019 em condições de aerobiose. Meyerozyma guilliermondii, Candida albicans, Rhodotorula mucilaginosa e Pichia membranifaciens foram leveduras encontradas nas kombuchas, das quais as duas últimas favoreceram a manutenção da alta viabilidade de HN019 em cocultura por 14 dias. Observou-se a viabilidade da bactéria acima de 9 log ao longo de todo o experimento, o que não foi observado em monocultura. Ademais, utilizou-se de análise de autoagregação, hidrofobicidade, atividade enzimática de proteases e fosfolipases das leveuras para analisar seu potencial patogênico. Observou-se que R. mucilaginosa demonstrou características semelhantes à Saccharomyces cerevisiae subsp. boulardii, e sua interação benéfica com HN019 reforça a possibilidade de que esta levedura seja uma chave para a inserção da bactéria em uma kombucha probiótica. Análises metabólicas foram realizadas e encontrou-se uma vasta diversidade de dipeptídeos, principalmente os compostos de prolina, durante a cocultura da bactéria com as leveduras. Tais dipeptídeos apresentam importantes mecanismos de ação no controle biológico e quorum sensing de bactérias e leveduras, e supostamente regulam a manutenção das relações mutualísticas entre ambos microrganismo

One of the biggest challenges in the development of probiotic products is to understand how microorganisms interact with each other and with the host. When we talk about traditional fermented foods, this obstacle increases because the food matrix already has an intrinsic microbiome. However, it is also known that many microorganisms can interact and cooperate to survive when stressful situations are encountered. Thus, the objective of this work was to isolate yeasts from four different kombuchas at different fermentation times and to verify the influence that yeasts isolated from kombucha have on maintaining the viability of the probiotic bacterium Bifidobacterium animalis subsp. lactis HN019 under aerobic conditions. Meyerozyma guilliermondii, Candida albicans, Rhodotorula mucilaginosa and Pichia membranifaciens were yeasts found in kombuchas, of which the last two favored the maintenance of HN019 high viability in co-culture for 14 days. Bacteria viability above 9 log was observed throughout the experiment, which was not observed in monoculture. In addition, analysis of autoaggregation, hydrophobicity, enzyme activity of proteases and phospholipases of yeasts was used to analyze their pathogenic potential. It was observed that R. mucilaginosa demonstrated characteristics similar to Saccharomyces cerevisiae subsp. boulardii, and its beneficial interaction with HN019 reinforces the possibility that this yeast is a key to the insertion of the bacterium in a probiotic kombucha. Metabolic analysis were performed and a wide diversity of dipeptides, mainly proline-based, was found during the co-culture of the bacteria with the yeasts. Such dipeptides have important mechanisms of action in the biological control and quorum sensing of bacteria and yeast, and supposedly regulate the maintenance of mutualistic relationships between both microorganism

Enhanced microbial biomass and lipid production through co-cultivation of yeast Rhodotorula toruloides and microalga Chaetoceros muelleri

Aims@#The synergistic bio-activity between oleaginous yeast and microalga has been recognized, which would enhance lipid production as biodiesel feedstock. Nevertheless, yeast and microalga require different conditions for optimal growth. In this study, the locally isolated oleaginous yeast Rhodotorula toruloides and microalga Chaetoceros muelleri were co-cultivated to enhance biomass and lipid production.@*Methodology and results@#The growth characteristics of both yeast and microalga monocultures were initially determined prior to optimizing the co-cultivation conditions. The biomass and lipid productivity of the co-culture were investigated and compared to their monocultures. The results showed that R. toruloides grew actively within 3 days while C. muelleri exhibited more prolonged cultivation, up to 21 days. The co-cultivation could be carried out optimally using growth media at pH 6, light intensity of 15,000 lux and yeast/microalga ratio of 1:2, yielding the highest biomass productivity determined at 0.18 g/l/day and lipid production of 17%. The lipid productivity of the co-culture increased by 42% and 75% as compared to monocultures of yeast and microalga, respectively. Furthermore, the biomass productivity was also higher than the monoculture, about 1.2-fold for the yeast and 13-fold for the microalga.@*Conclusion, significance and impact of study@#The findings revealed that co-cultivation of yeast and microalga is a viable technique for long-term microbial oil production.

Producción de carotenoides en levaduras nativas aisladas de sistemas acuáticos en Cali, Colombia / Carotenoids production in wild yeasts isolated from aquatic systems in Cali, Colombia

Introducción: Los carotenoides son fuente importante de actividades biológicas funcionales, tales como antioxidantes o antimicrobianas, además de tener gran impacto a nivel industrial, ya sea en cosmética o suplementación animal en acuacultura. Se han reportado varias moléculas novedosas a partir de aislamientos en Latinoamérica, principalmente en la Patagonia, Argentina. Sin embargo, no hay reportes en Colombia que evalúen la producción de carotenoides en levaduras nativas pigmentadas. Objetivo: Se evaluó la capacidad de producción de carotenoides en levaduras nativas aisladas de lagos, ríos y aguas residuales de la ciudad de Cali, Colombia. Materiales y métodos: Se caracterizaron 30 levaduras provenientes de dos colecciones. De estas se obtuvo su biomasa, rendimiento de carotenoides totales y producción de ß-caroteno. Las cepas promisorias fueron identificadas secuenciando la región ITS1-5.8S-ITS2. Resultados: El mayor rendimiento en la extracción de pigmentos se obtuvo para las cepas P11A (84,36 ± 5,24 µg/g) y Rhodotorula paludigena CS13 (56,26 ± 7,08 µg/g), mientras que las concentraciones más altas de ß-caroteno fueron 10,2 µg/mL (R. paludigena CS13) y 9,7 µg/mL (R. mucilaginosa/alborubescens P10A). La cinética de crecimiento y producción de pigmentos durante cinco días fue óptima para la cepa P11A, ya que hubo un aumento en el rendimiento de carotenoides totales 10 veces mayor (48 h: 109,62 µg/g, 120 h: 1403,10 µg/g). Conclusiones: En este estudio se encontró que levaduras aisladas de sistemas acuáticos son promisorias para la producción de pigmentos carotenoides (incluyendo ß-caroteno), siendo su extracción y caracterización viable para futuros estudios biotecnológicos.

Introduction: Carotenoids are an important source of biological activities, such as antioxidant or antimicrobial. Also, carotenoids impact the cosmetic or food supplement industry, mainly in aquaculture. Several reports in Latin America showed novel molecules, mainly in isolated strains in Patagonia, Argentina. However, in Colombia, there are not reports about carotenoid production from pigmented wild yeasts. Objective: We assessed the carotenoid production ability in wild yeasts isolated from lakes, wastewater and rivers located in Cali, Colombia. Materials and methods: 30 yeasts were selected from two collections, each of them was characterized by the biomass, yield of total carotenoids and ß-carotene production. Promisor strains were identified with sequence analysis of ITS1-5.8S-ITS2 region. The highest yield in pigment extraction was obtained by strains P11A (84,36 ± 5,24 µg/g) and Rhodotorula paludigena CS13 (56,26 ± 7,08 µg/g), while higher concentrations of ß-carotene were 10,2 µg/mL (R. paludigena CS13) and 9,7 µg/mL (R. mucilaginosa/alborubescens P10A). The kinetics of growth and pigment production for five days was optimal for the P11A strain, where we found an increasing 10-fold higher (48 h: 109,62 µg/g, 120 h: 1403,10 µg/g). Conclusions: We suggest that yeasts isolated from aquatic systems are promising for the production of carotenoid pigments (including ß-carotene), making their extraction and characterization viable for future biotechnological studies.

Infección por Rhodotorula rubra en el lactante con leucemia linfoblástica aguda. Reporte de un caso / Rhodotorula rubra infection in infants with acute lymphoblastic leukemia. Case report

Rhodotorula especies (spp.) son levaduras comensales de la familia Sporidiobolaceae. Rhodotorula rubra es un patógeno oportunista y emergente que tiene la habilidad de colonizar e infectar a los pacientes susceptibles como son los que padecen de enfermedades hematológicas malignas, y está asociado con el uso de catéteres venosos centrales. Hay pocos reportes de casos en niños inmunocomprometidos. Presentamos el caso de una paciente lactante con diagnóstico de leucemia linfoblástica aguda (LLA) B común, que presentó infección fúngica por Rhodotorula rubra.

Rhodotorula species (spp.) are commensal yeasts of the family Sporidiobolaceae. Rhodotorula rubra is an opportunistic and emerging pathogen with the ability to colonize and infect susceptible patients like patients with malignant haematological diseases and it is associated with the use of central venous catheters. Only a few reports have linked found in immunocompromised children. In this article we present the case report of a lactating patient with a diagnosis of common acute lymphoblastic leukemia (B), who presented a fungal infection by Rhodotorula rubra.

Fungemia causada por Rhodotorula en un lactante crítico / Fungemia caused by Rhodotorula in a critical infant

Introducción: Rhodotorula es considerada un microorganismo contaminante no virulento. Forma parte de la microbiota de la piel, las uñas y las mucosas. Se aísla con frecuencia del ambiente humanizado. Estas levaduras han surgido como patógenos oportunistas en pacientes con inmunodeficiencias, portadores de catéteres intravenosos de larga duración y otros. Objetivo: Informar a la comunidad pediátrica un nuevo caso de fungemia causada por Rhodotorula. Presentación del caso: lactante de 2 meses de edad, pretérmino de 32,1 semanas, con un peso al nacer de 1 800 gramos, que ingresa en la sala de cuidados intensivos del Hospital Pediátrico Provincial, Cienguegos, con el diagnóstico de una sepsis sin un foco primario definido. Después de 5 días de tratamiento con meropenem y vancomicina la fiebre cede y reaparece nuevamente pasados otros 5 días. En el momento en que la fiebre se reanuda tenía un catéter centrovenoso de ocho días de duración. En los hemocultivos realizados en esa fecha se aisló una Rhodotorula sp. Conclusiones: A pesar de que Rhodotorula es un microorganismo de baja virulencia, debe considerarse un potencial patógeno en pacientes con inmunosupresión y catéteres venosos centrales. Las especies de Rhodotorula se consideran intrínsecamente resistentes a los azoles y las equinocandinas, pero susceptibles a anfotericina B y flucitosina. En consecuencia, el tratamiento de elección preferido es con cualquier tipo de preparación de anfotericina B. El resultado alcanzado constituye un llamado de atención para la comunidad pediátrica nacional y foránea(AU)

ABSTRACT Introduction: Rhodotorula is considered a contaminating, non-virulent microorganism. It is part of the microbiota of the skin, nails and mucous membranes. It is often isolated from the humanized environment. These yeasts have emerged as opportunistic pathogens in patients with immunodeficiencies carrying long-term intravenous catheters. Objective: To inform to the pediatricians´ community a new case of fungemia due to Rhodotorula. Case presentation: 2-month-old, preterm infant of 32.1 weeks, with a birth weight of 1800 grams, who was admitted to Intensive Care service in Provincial Pediatric Hospital of Cienfuegos province with a diagnosis of sepsis without a defined primary focus. After 5 days of treatment with meropenem and vancomycin, the fever subsides and reappears again after another 5 days. By the time the fever reappears he had an 8-day central venous catheter. In the blood cultures carried out on that date a Rhodotorulasp was isolated. Conclusions: Although Rhodotorula is a low virulence microorganism, it should be considered as a potential pathogen in patients with immunosuppression and central venous catheters. Rhodotorula species are considered intrinsically resistant to azoles and echinocandins, but sensitive to amphotericin B and flucytosine. Consequently, the preferred treatment of choice is with any type of amphotericin B preparations. The results achieved constitute a call of attention to the national and foreign pediatrics´ community(AU)

Process conditions for a rapid in situ transesterification for biodiesel production from oleaginous yeasts

BACKGROUND: Microbial oils produced by diverse microorganisms are being considered as alternative sources of triglycerides for biodiesel production. However, the standalone production of biodiesel from microorganisms is not currently economically feasible. In case of yeasts, the use of low-value nutrient sources in microbial production and the implementation of cost-efficient downstream processes could reduce costs and make microbial lipids competitive with other commodity-type oils in biodiesel production. Industrial biodiesel synthesis from oleaginous seeds is currently based on a multistep process. However, a simple process called in situ transesterification (ISTE), which takes place within the biomass without a previous lipid extraction step, is receiving increasing interest. In this work, the optimal conditions for an ISTE process to obtain biodiesel from previously selected oleaginous yeast (Rhodotorula graminis S1/S2) were defined using the response surface methodology (RSM). RESULTS: Using the RSM approach, the optimal conditions for the maximum yield with minimum reaction time included a methanol-to-biomass ratio of 60:1, 0.4 M H2SO4, and incubation at 70°C for 3 h. The optimized in situ process yield was significantly higher (123%) than that obtained with a two-step method in which fatty acids from saponifiable lipids were first extracted and then esterified with methanol. The composition of the fatty acid methyl ester mixture obtained from R. graminis S1/S2 by ISTE met Uruguayan standards for biodiesel. CONCLUSION: The characteristics achieved by the optimized method make microbial oil a potential alternative for biodiesel production from yeast at an industrial scale.

Development of Rhodotorula mucilaginosa strain via random mutagenesis for improved lipid production

Aims@#Oleaginous yeasts are widely used for the production of biodiesel feedstocks because of their high lipid content. This research was aimed to conduct random mutagenesis of Rhodotorula mucilaginosa using ethyl methane sulfonate (EMS) and identify the mutants with improved lipid production. @*Methodology and results@#A total of twenty-two mutant isolates prescreened with cerulenin were produced and further characterized via M13 PCR fingerprinting to determine their polymorphism and genetic distances. Eight strains, namely M1, M2, M3, M4, M7, M10, M11 and M18, were chosen based on their genetic distances from the parental strain for biomass production. Six mutants (M1, M2, M3, M4, M7 and M18) showing the highest dry cell weights were further selected for evaluation of lipid production in a laboratory-scale bioreactor using glucose as a carbon source. Results indicated that parental strain exhibited lipid content of 1.83 g/L, while strains M1, M2, M3, M7 and M18 generated 2.37 g/L, 2.27 g/L, 2.27 g/L, 3.10 g/L and 3.83 g/L of intracellular lipid, respectively. These five mutants were identified to have significant increase in lipid production compared to the parental strain. @*Conclusion, significance and impact of study@#This study demonstrated enhanced lipid production in R. mucilaginosa by random mutagenesis. New generated strains had higher lipid productivity compared to parental strain and application of these strains in industry may reduce the overall cost of biodiesel production.

Production of pigments by Rhodotorula mucilaginosa

Aims@#Pigments have a large and growing market in the world. Drawbacks in their production such as raw materials availability and low productivity prompt the search for fermentation routes for industrial production. A carotenoid-producing yeast identified as Rhodotorula mucilaginosa was isolated in our laboratory. The aim of this study was to investigate the growth and carotenoid production capacity of the yeast.@*Methodology and results@#A cost-effective substrate of sago starch hydrolysate (SSH) derived from sago fiber waste was used for the fermentation. The fermentation was carried out for 96 h at 27 °C in batch mode. The biomass produced during 5 days of fermentation was 9.6 g/L, which contained a carotenoid concentration of 8.1 mg/L and a specific yield of 845.9 g/g.@*Conclusion, significance and impact of study@#The results demonstrated the capacity of R. mucilaginosa yeast to produce carotenoids and its potential for larger-scale production.

Aislamiento e identificación de levaduras degradadoras de hidrocarburos aromáticos, presentes en tanques de gasolina de vehículos urbanos / Isolation and identification of aromatic hydrocarbon degrading yeasts present in gasoline tanks of urbans vehicles

RESUMEN Se obtuvieron aislamientos de levaduras a partir de muéstreos en tanques de combustible de vehículos urbanos, con el objeto de evaluar su potencial actividad de degradación de hidrocarburos aromáticos derivados del petróleo. Se realizaron ensayos de crecimiento en medio mínimo mineral sólido utilizando distintos hidrocarburos (benceno, tolueno, naftaleno, fenantreno, y pireno). Los aislamientos que presentaron crecimiento notorio en alguno de los hidrocarburos aromáticos policíclicos fueron identificados mediante secuenciación Sanger de los marcadores moleculares ITS1 e ITS2 del ARNr. Se obtuvieron 16 aislados de levaduras, de las cuales tres presentaron crecimiento conspicuo con hidrocarburos aromáticos como única fuente de carbono. Las cepas identificadas pertenecen al género Rhodotorula y corresponden a las especies Rhodotorula calyptogenae (99,8% de identidad) y Rhodotorula dairenensis (99,8% de identidad). Dichas cepas presentaron crecimiento en benceno, tolueno, naftaleno, fenantreno. En este estudio se reporta por primera vez la presencia de levaduras del género Rhodotorula que habitan los ductos y tanques de gasolina de vehículos urbanos, así como su capacidad para utilizar distintos hidrocarburos aromáticos que son contaminantes para el medio ambiente. Estos resultados sugieren que dichas levaduras constituyen potenciales candidatos para la degradación de éstos compuestos, como parte de estrategias de biorremediación.

ABSTRACT Yeast isolates were obtained from fuel tanks of vehicles in order to assess their potential use in the degradation of aromatic hydrocarbons. Growth assays were performed in minimum mineral medium using different aromatic hydrocarbons (benzene, toluene, naphthalene, phenanthrene, and pyrene) as the sole carbon source. Isolates that showed growth in any of the tested polycyclic aromatic hydrocarbons were identified by Sanger sequencing of the ITS1 and ITS2 rDNA molecular markers. A total of 16 yeasts strains were isolated, and three showed remarkable growth in media with aromatic hydrocarbons as the sole carbon source. These strains belong to the genus Rhodotorula, and correspond to the species Rhodotorula calyp-togenae (99,8% identity) and Rhodotorula dairenensis (99,8% identity). These strains grew in benzene, toluene, naphthalene, phenanthrene and pyrene. This study demonstrates for the first time that yeasts of the genus Rhodotorula inhabit pipelines and fuel tanks of vehicles and that remove aromatic hydrocarbons that are environmental pollutants. Our results suggest that these yeasts are potential candidates for aromatic hydrocarbon degradation as part of bioremediation strategies.

Probable fungemia por Rhodotorula mucilaginosa asociada a catéter venoso central en un paciente pediátrico: presentación de un caso / Probable fungemia by rhodotorula mucilaginosa associated to a central venous catheter in a pediatric pacient: a case report

Las levaduras del género Rhodotorula son patógenos oportunistas emergentes, especialmente en pacientes inmunocomprometidos. Se presenta el caso de un niño de 9 años con sarcoma de Ewing en tratamiento con quimioterapia que cursó con una probable fungemia por Rhodotorula mucilaginosa. Se identificaron varios factores de riesgo tales como la presencia de un catéter venoso central (CVC) y una neoplasia maligna sólida. El diagnóstico se realizó a través de un hemocultivo de una rama del CVC. Nuestra cepa fue identificada como R. Mucilaginosa por morfofisiología y pruebas bioquimicas. El éxito terapeutico se basó en el retiro del CVC y en el tratamiento con anfotericina B desoxicolato como primera alternativa.

Yeasts from Rhodotorula genus are opportunistic pathogen that emerge especially in immunocompromised patients. We report a case of a 9-years-old boy, he developed an Ewing’s sarcoma that was treated with chemotherapy an underwent with problable fungemia by Rhodotorula mucilaginosa. Several risk factors were identified such as presence of a central venous catheter (CVC) and a solid malignant neoplasm. The diagnosis was made by blood culture of a branch of the CVC. Our isolated was identified as R. mucilaginosa by morphofisiology and biochemical test. The therapy did success based on withdrawal of CVC and treatment with amphotericin B deoxycholate as the first alternative.

Oxidative Stress, Chromium-Resistance and Uptake by Fungi: Isolated from Industrial Wastewater

ABSTRACT Trichosporon asahii and Rhodotorula mucilaginosa isolated from wastewater effluents were identified as chromium-resistant yeasts. Cr(VI) concentrations at 8 mM and 6 mM were inhibitory for R. mucilaginosa and T. asahii. Remarkably elevated GSH (69.88 ± 10.01) and GSSG (11.24 ± 0.96) was observed under metal stress in T. asahii as compared to R. mucilaginosa GSH (18.95 ± 3.19) and GSSG (3.7 ± 2.74) mM g-1 8 level. Statistical analysis revealed significantly higher GSH/GSSG ratio in both strains. NPSH (29.84 ± 0.54) level in T. asahii was much higher than in R. mucilaginosa (6.05 ± 0.24). Chromate reductase (ChR) was assayed and its activity was optimum at 50°C (pH 6) in T. asahii while R. mucilaginosa showed higher activity at 30°C (pH 7). Activity of both ChRs was enhanced in the presence of Mg, Na, Co and Ca but strongly inhibited by Hg cations. Cr(VI) uptake capabilities were ranged between 43-97% in R. mucilaginosa and 35-88% in T. asahii. One dimensional electrophoresis revealed enriched bands of cysteine rich metallothioneins suggesting some differential proteins could be overexpressed under Cr(VI) stress.

Peritonitis fúngica por Rhodotorula mucilaginosa en una paciente en diálisis peritoneal automatizada: revisión de la literatura / Fungal peritonitis due to Rhodotorula mucilaginosa in a patient with automated peritoneal dialysis: literature review

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.

La peritonitis fúngica es una complicación mayor de la diálisis peritoneal, con una alta mortalidad asociada y la mayoría de los sobrevivientes presentan una alta tasa de abandono de diálisis peritoneal como terapia de reemplazo renal. Se presenta un caso de peritonitis fúngica por un agente infrecuente. Mujer de 83 años, diabética con múltiples episodios de peritonitis bacteriana asociada a fallas técnicas en la ejecución de diálisis peritoneal automatizada, ingresa por cuadro clínico de dolor abdominal y líquido peritoneal turbio. Se confirmó la presencia de Rhodotorula mucilaginosa en líquido peritoneal mediante MALDI-TOF. Fue tratada con retiro del catéter y posaconazol oral por 14 días, presentando una evolución favorable.

Sepsis Due to Rhodotorula mucilaginosa in a Patient with Advanced Non-Small Cell Lung Cancer

Rhodotorula species are round to oval-shaped, multilateral budding, encapsulated yeasts that produce urease and do not ferment carbohydrates. Rhodotorula species form characteristic salmon-pink colored colonies owing to carotenoid pigment production. These yeasts form a part of the normal flora of moist skin and are found in the environment. Rhodotorula was traditionally considered a contaminant but is now progressively recognized as a human pathogen, especially in immunocompromised patients with central venous catheters. However, isolation of Rhodotorula species from blood has been very rarely reported in Korea. We report a case of sepsis due to Rhodotorula mucilaginosa infection in a patient who had received chemotherapy and supportive care for non-small cell lung cancer.

Analysis of fungal colonization in skin surfaces of patients with atopic dermatitis / 中华皮肤科杂志

Objective To analyze the colonization of Candida, Rhodotorula, Penicillium and Aspergillus in skin surfaces of patients with atopic dermatitis, and to assess the relationship between the four common fungal allergens and severity of atopic dermatitis. Methods Fifty patients with atopic dermatitis and 20 healthy controls were enrolled. Scales were scraped from lesional and non?lesional skin of flexural extremities of the patients, as well as from normal skin of the flexural elbow of healthy controls, then were subjected to microscopic examination and culture. Scale specimens were inoculated onto Sabouraud dextrose agar medium and cultured at 25 ℃ in a constant temperature incubator. Subsequently, suspected fungal or yeast?like colonies were collected for pure culture. Finally, fungal strains were identified according to colony morphology, color, growth speed, as well as microscopic features of spores and hyphae. Results No hyphae or pseudohyphae were found in any case by microscopic examination. Candida albicans and Rhodotorula were detected in 29(58%)and 17(34%)out of the 50 patients, respectively, and in 5(25%)and 2 (10%) out of the 20 healthy controls, respectively. The detection rates of Candida albicans and Rhodotorula were significantly higher in the patients than in the controls(χ2=6.23, 4.10, respectively, both P<0.05). Of 25 patients with severe lesions, 19(76%)and 12(48%)were colonized by Candida albicans and Rhodotorula respectively;among 25 patients with moderate lesions, 10 (40%) and 5 (20%) were colonized by Candida albicans and Rhodotorula respectively. An increase was observed in the detection rates of Candida albicans and Rhodotorula in the patients with severe lesions compared with those with moderate lesions(χ2=6.65, 4.37, respectively, both P<0.05). There was no significant difference in the detection rate of Penicillium or Aspergillus between the patients and health controls. Conclusion The colonization rates of Candida albicans and Rhodotorula on skin surfaces were higher in patients with atopic dermatitis than in healthy controls, and higher in patients with severe lesions than in patients with moderate lesions, indicating that the types of colonizing fungi are associated with the health status of skin and severity of symptoms in patients with atopic dermatitis.

Biodegradation of deproteinized potato wastewater and glycerol during cultivation of Rhodotorula glutinis yeast

Background Deproteinized potato wastewater and glycerol are two by-products which are difficult to dispose. The objective of this study was to determine the ability of Rhodotorula glutinis to use glycerol and nitrogen compounds present in deproteinized potato wastewater and to evaluate the ability of simultaneous biodegradation of potato wastewater and glycerol via microbiological methods. Results It has been found that R. glutinis used glycerol and potato wastewater as a source of carbon and nitrogen, respectively. The highest degree of glycerol content (70.6%) reduction was found after cultivation of the investigated strain using a medium with 5% glycerol. In this medium, a significant reduction in the total protein content, estimated at 61%, was observed. The process of 72 h cultivation of yeast in a medium containing potato wastewater and 5% glycerol reduced the chemical oxygen demand (COD) more than 77%. Supplementation of media with high doses of glycerol (i.e. 20 and 25%) led to decreased metabolic activity in the yeast strain tested. Conclusion It has been found that there is a possibility of simultaneous biodegradation of potato wastewater and glycerol during the cultivation of R. glutinis.

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

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.

Rhodotorula glutinis and Its Two Mutants Ameliorate Hepato-Renal Dysfunction Induced by Ochratoxin A on Rats.

Aim: This study was designed to investigate the possible curative effect of Rhodotorula glutinis (R. glutinis) and its two mutants (Col-1R1 and Col-1R3) against hepatorenal toxicity induced by ochratoxin (OA) in rat. Methods: The strains of yeast Col- 1R1 and Col- 1R3 have been genetically improved and isolated from R. glutinis after colchicines treatment. OA was produced and determined from Aspergillus ochracus isolate from Egyptian corn. Experimental design: Five groups of rats were treated as follows: group 1, was the control group orally given 4 ml / Kg 0.1 M NaCOH3; group 2 treated with OA (1.7 mg /Kg).Groups 3, 4 and 5 orally administered the R. glutinis and its two mutants (50 X106 colony forming unit (cfu) / 10 ml saline / kg body weight) prior 1hr of OA -treatment for 15 successive days. Results: The studied autoploidy strains showed significant increase in caratenoids level, protease, β-1, 3-glucanase and chitinase activities when compared with the parental strain. Biochemical results revealed that OA significantly decreased serum total antioxidant capacity (TAC) and it caused elevation inserum transaminases (AST, ALT), creatinine, uric acid, nitric oxide (NO), tumor necrosis factor alpha (TNF-α) and carcinoembryonic antigen (CEA) (P <0.05) as compared with the control group. The three tested yeasts significantly decreased the elevated values toward the normal levels and improved the pathological feature in liver and kidney tissues. Moreover, R. glutinis and the two mutants significantly reduced hepatorenal damaged arias, increased optical density of DNA and alleviated ochratoxin A-induced caspase-3 activation. The resultant effect of the two mutant strains had more powerful effect more than the wild strainto ameliorate hepatorenal dysfunction in ochratoxicosis-rat. Conclusion: Col-1R3 was more effective than Col-1R1 may be due to its higher contents of carotenoids, glucane and chitine, which act as antioxidants.

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

Background: Rhodotorula spp. are an emergent opportunistic pathogen, particularly in immunocompromised individuals. Materials and Methods: 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. Results: 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). Conclusions: 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.