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The present study aims to analyze the interaction between Rhodotorula toruloides and magnetic nanoparticles and evaluate their effect on carotenoid production. The manganese ferrite nanoparticles were synthesized without chitosan (MnFe2O4) and chitosan coating (MnFe2O4-CS) by the co-precipitation method assisted by hydrothermal treatment. XRD (X-ray diffraction), Magnetometry, Dynamic Light Scattering (DLS) and FTIR (Fourier-Transform Infrared Spectroscopy), are used to characterize the magnetic nanoparticles. The crystallite size of MnFe2O4 was 16 nm for MnFe2O4 and 20 nm for MnFe2O4-CS. The magnetic saturation of MnFe2O4-CS was lower (39.6 ± 0.6 emu/g) than the same MnFe2O4 nanoparticles (42.7 ± 0.3 emu/g), which was attributed to the chitosan fraction presence. The MnFe2O4-CS FTIR spectra revealed the presence of the characteristic chitosan bands. DLS demonstrated that the average hydrodynamic diameters were 344 nm for MnFe2O4 and 167 nm for MnFe2O4-CS. A kinetic study of cell immobilization performed with their precipitation with a magnet demonstrated that interaction between magnetic nanoparticles and R. toruloides was characterized by an equilibrium time of 2 h. The adsorption isotherm models (Langmuir and Freundlich) were fitted to the experimental values. The trypan blue assay was used for cell viability assessment. The carotenoid production increased to 256.2 ± 6.1 µg/g dry mass at 2.0 mg/mL MnFe2O4-CS. The use of MnFe2O4-CS to stimulate carotenoid yeast production and the magnetic separation of biomass are promising nanobiotechnological alternatives. Magnetic cell immobilization is a perspective technique for obtaining cell metabolites.

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It is known that selenium (Se) is an essential trace element, important for the growth and other biological functions of fish. One of its most important functions is to contribute to the preservation of certain biological components, such as DNA, proteins, and lipids, providing protection against free radicals resulting from normal metabolism. The objective of this study was to evaluate and optimize selenium accumulation in the native yeast Rhodotorula mucilaginosa 6S. Sodium selenite was evaluated at different concentrations (5-10-15-20-30-40 mg/L). Similarly, the effects of different concentrations of nitrogen sources and pH on cell growth and selenium accumulation in the yeast were analyzed. Subsequently, the best cultivation conditions were scaled up to a 2 L reactor with constant aeration, and the proteome of the yeast cultured with and without sodium selenite was evaluated. The optimal conditions for biomass generation and selenium accumulation were found with ammonium chloride and pH 5.5. Incorporating sodium selenite (30 mg/L) during the exponential phase in the bioreactor after 72 h of cultivation resulted in 10 g/L of biomass, with 0.25 mg total Se/g biomass, composed of 25% proteins, 15% lipids, and 0.850 mg total carotenoids/g biomass. The analysis of the proteomes associated with yeast cultivation with and without selenium revealed a total of 1871 proteins. The results obtained showed that the dynamic changes in the proteome, in response to selenium in the experimental medium, are directly related to catalytic activity and oxidoreductase activity in the yeast. R. mucilaginosa 6S could be an alternative for the generation of selenium-rich biomass with a composition of other nutritional compounds also of interest in aquaculture, such as proteins, lipids, and pigments.

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Rhodotorula mucilaginosa survives extreme conditions through several mechanisms, among them its carotenoid production and its branched mitochondrial respiratory chain (RC). Here, the branched RC composition was analyzed by biochemical and complexome profiling approaches. Expression of the different RC components varied depending on the growth phase and the carbon source present in the medium. R. mucilaginosa RC is constituted by all four orthodox respiratory complexes (CI to CIV) plus several alternative oxidoreductases, in particular two type-II NADH dehydrogenases (NDH2) and one alternative oxidase (AOX). Unlike others, in this yeast the activities of the orthodox and alternative respiratory complexes decreased in the stationary phase. We propose that the branched RC adaptability is an important factor for survival in extreme environmental conditions; thus, contributing to the exceptional resilience of R. mucilaginosa.

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Oleaginous yeasts are promising platforms for microbial lipids production as a renewable and sustainable alternative to vegetable oils in biodiesel production. In this paper, a thorough in silico assessment of lipid production in batch cultivation by Rhodosporidium toruloides was developed. By means of dynamic flux balance analysis, the traditional two-stage bioprocess (TSB) performed by the native strain was contrasted with one-stage bioprocess (OSB) using four designed strains obtained by gene knockout strategies. Lipid titer, yield, content, and productivity were analyzed at different initial C/N ratios as relevant performance indicators used in bioprocesses. By weighting these indicators, a global lipid efficiency metric (GLEM) was defined to consider different scenarios. Under simulated conditions, designed strains for lipid overproduction in OSB outperformed the TSB in terms of lipid title (up to threefold), lipid yield (up to 2.4-fold), lipid content (up to 2.8-fold, with a maximum of 76%), and productivity (up to 1.3-fold), depending on C/N ratios. Using these efficiency parameters and the proposed GLEM, the process of selecting the most suitable candidates for lipid production could be carried out before experimental assays. This methodology holds the potential to be extended to other oleaginous microorganisms and diverse strain design techniques.

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In this work, a new isolate yeast, namely Rhodotorula toruloides KP324973, was examined for ß-carotene production from corn steep liquor (CSL) as a sole carbon source because CSL as the by-product of corn wet-milling process mainly enriched from the water-soluble carbohydrates. The studies were preliminary performed at the shaken flasks, and then developed at batch and fed-batch modes in a bubble column reactor (BCR). Application of the BCR improved the carotenogenesis of the cells in comparison with shaken flasks and the specific ß-carotene production rate (Rp) and the yield of ß-carotene production from the total reducing sugars (YP/TRS) reached 2.23 mg gcell-1 h-1 and 36.82 mg gTRS-1, respectively. Further studies were carried out to optimize the operational factors of the BCR for a fed-batch production by the response surface methodology. An optimal condition at a feed flow rate of 2.5 mL h-1, temperature 11.7°C, and initial pH of 6.1 obtained the highest Rp = 12.31 mg gcell-1 h-1 and YP/TRS = 97.18 mg gTRS-1.

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Microorganisms showed unique mechanisms to resist and detoxify harmful metals in response to pollution. This study shows the relationship between presence of heavy metals and plant growth regulator compounds. Additionally, the responses of Rhodotorula mucilaginosa YR29 isolated from the rhizosphere of Prosopis sp. growing in a polluted mine jal in Mexico are presented. This research carries out a phenotypic characterization of R. mucilaginosa to identify response mechanisms to metals and confirm its potential as a bioremediation agent. Firstly, Plant Growth-Promoting (PGP) compounds were assayed using the Chrome Azurol S (CAS) medium and the Salkowski method. In addition, to clarify its heavy metal tolerance mechanisms, several techniques were performed, such as optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) supplemented with assorted detectors. Scanning transmission electron microscopy (STEM) was used for elementary mapping of the cell. Finally, yeast viability after all treatments was confirmed by confocal laser scanning microscopy (CLSM). The results have suggested that R. mucilaginosa could be a PGP yeast capable of triggering Pb2+ biosorption (representing 22.93% of the total cell surface area, the heavy metal is encapsulated between the cell wall and the microcapsule), and Pb2+ bioaccumulation (representing 11% of the total weight located in the vacuole). Based on these results, R. mucilaginosa as a bioremediation agent and its wide range of useful mechanisms for ecological purposes are highlighted.

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Biofilms are important to the virulence of human pathogenic fungi, and some molecules have been found to play key roles in the growth and regulation of fungal biofilms. Farnesol, one of these molecules, is well-described for some microorganisms but is still scarcely known for Rhodotorula spp. This study aimed to evaluate the influence of farnesol on the biofilm of R. mucilaginosa. Initially, screening with 0.2 mM to 2.1 mM of farnesol was evaluated against planktonic forms. A concentration of this compound was then chosen and evaluated for its effect on biofilm in formation and on preformed biofilm after 24, 48 and 72 hours. The impact of farnesol was evaluated by colony-forming units (CFU) counts, determination of metabolic activity and quantification of total biomass. In the presence of 0.9 mM, farnesol was able to decrease the CFU number, at 48 hours, when the biofilm was in formation, although it did not affect the preformed biofilms. Thus, our results show that farnesol exerts a modulating activity during biofilm formation for R. mucilaginosa, with this compound reducing the metabolic activity and total biomass of the biofilms.

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The development of an effective, realistic, and sustainable microbial biorefinery depends on several factors, including as one of the key aspects an adequate selection of microbial strain. The oleaginous red yeast Rhodotorula sp. has been studied as one powerful source for a plethora of high added-value biomolecules, such as carotenoids, lipids, and enzymes. Although known for over a century, the use of Rhodotorula sp. as resource for valuable products has not yet commercialized. Current interests for Rhodotorula sp. yeast have sparked from its high nutritional versatility and ability to convert agro-food residues into added-value biomolecules, two attractive characteristics for designing new biorefineries. In addition, as for other yeast-based bioprocesses, the overall process sustainability can be maximized by a proper integration with subsequent downstream processing stages, for example, by using eco-friendly solvents for the recovery of intracellular products from yeast biomass. This review intends to reflect on the current state of the art of microbial bioprocesses using Rhodotorula species. Therefore, we will provide an analysis of bioproduction performance with some insights regarding downstream separation steps for the extraction of high added-value biomolecules (specifically using efficient and sustainable platforms), providing information regarding the potential applications of biomolecules produced by Rhodotorula sp, as well as detailing the strengths and limitations of yeast-based biorefinery approaches. Novel genetic engineering technologies are further discussed, indicating some directions on their possible use for maximizing the potential of Rhodotorula sp. as cell factories. KEY POINTS: • Rhodotorula sp. are valuable source of high value-added compounds. • Potential of employing Rhodotorula sp. in a multiple product biorefinery. • Future perspectives in the biorefining of Rhodotorula sp. were discussed.

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We assessed the potentially pathogenic fungi present in Antarctic permafrost and the overlying active layer on King George, Robert, Livingston and Deception Islands in the South Shetland Islands archipelago, maritime Antarctica. Permafrost and active layer sub-samples were incubated at 37 °C to select fungi able to grow inside the human body. A total of 67 fungal isolates were obtained, 27 from the permafrost and 40 from the active layer. These represented 18 taxa of the genera Alternaria, Aspergillus, Curvularia, Penicillium, Rhodotorula and Talaromyces. The majority of fungi detected occurred exclusively either in the permafrost or the active layer at each site. Only Aspergillus thermomutatus, Penicillium cf. chrysogenum and Rhodotorula cf. mucilaginosa were present in both permafrost and active layer samples from the same site. The yeast R. cf. mucilaginosa was recovered from both in at least two sites. The genus Penicillium was the most abundant and widely distributed genus in both permafrost and active layer samples across the sites sampled. All fungal isolates were screened using enzymatic, pH and antifungal assays to identify their virulence potential. Aspergillus hiratsukae, A. thermomutatus and R. cf. mucilaginosa, known human opportunistic fungi, were identified, displayed phospholipase, esterase, proteinase and hemolytic activities. All three also displayed the ability to grow at 40°, 45° and/or 50 °C and resistance to fluconazole and itraconazole; additionally, R. cf. mucilaginosa showed resistance to amphotericin B and viability after 100 d at -80 °C. A. thermomutatus UFMGCB 17415 killed the entire larvae of Tenebrio molitor in six days and R. cf. mucilaginosa UFMGCB 17448 and 17473 in three and four days, respectively. The melting of maritime Antarctic permafrost as a result of climate change may threaten the release of wild strains of pathogenic fungi geographically isolated for long time, which may in turn be transported within and beyond Antarctica by different biological and non-biological vectors.

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Low-cost substrates are an exciting alternative for bioprocesses; however, their complexity can affect microorganism metabolism with non-desirable outcomes. This work evaluated banana peel extract (BPE) as a growth medium compared to commercial Yeast-Malt (YM) broth in the native and non-conventional yeast Rhodotorula mucilaginosa UANL-001L. The production of carotenoids, fatty acids, and exopolysaccharides (EPS) was also analyzed. Biomass concentration (3.9 g/L) and growth rate (0.069 g/h) of Rhodotorula mucilaginosa UANL-001L were obtained at 200 g/L of BPE. Yields per gram of dry biomass for carotenoids (317 µg/g) and fatty acids (0.55 g/g) showed the best results in 150 g/L of BPE, while 298 µg/g and 0.46 mg/g, respectively, were obtained in the YM broth. The highest yield of EPS was observed in 50 g/L of BPE, a two-fold increase (160.1 mg/g) compared to the YM broth (76.3 mg/g). The fatty acid characterization showed that 100 g/L of BPE produced 400% more unsaturated compounds (e.g., oleic and ricinoleic acid) than the YM broth. Altogether, these results indicate that BPE is a suitable medium for producing high-value products with potential industrial applications.

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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)

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Biodiesel generated by transesterification of triglycerides from renewable sources is a clean form of energy that is currently used in many countries in blends with petrodiesel. It is mainly produced from food-grade vegetable oils obtained from oleaginous crops. High prices of these oils have made the sustainability of biodiesel production questionable. The use of nonedible feedstocks, such as intracellular triglycerides accumulated by oleaginous yeasts, appears as a feasible alternative. However, it has been demonstrated that an economically sustainable production of yeast oil could only be possible if low-cost media based on industrial subproducts, or wastes are used. In this work, we propose intracellular lipids production by a previously selected oleaginous yeast strain in a medium composed only by sugar cane vinasse and crude glycerol. Different culture strategies were studied. The highest biomass and lipid yields were obtained when the yeast R. graminis S1/2R was cultivated in batch without control of dissolved oxygen. The fatty acid methyl esters obtained under these conditions met the specification of international biodiesel standards.

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This study focuses on the potential of Rhodotorula mucilaginosa CCT 7688 in simultaneous production of lipids and carotenoids in agroindustrial byproduct-based media and specially aims at establishing a process condition that guarantees high concentrations of both bioproducts, i.e., a carotenoid-rich microbial oil with potential economic value and health benefits attributed to carotenoids and fatty acids. Four different combinations of cultivation modes (batch and fed-batch) and alternative substrates (crude glycerol, sugarcane molasses and corn steep liquor) were tested. The M2-B assay, which comprises the use of an agroindustrial byproduct-based medium without any supplementation (70 g L-1 sugarcane molasses and 3.4 g L-1 corn steep liquor) and batch mode, was selected as the most promising one to produce both compounds. Total carotenoid production and total lipid content were 1794.2 µg L-1 and 43.2% (w/w), respectively, after 144 h of cultivation. The fatty acid profile showed predominance of oleic acid (69.9%) and palmitic acid (23.2%). Thus, R. mucilaginosa CCT 7688 may be used in simultaneous production of lipids and carotenoids successfully; its fatty acid profile is similar to that found in olive oil. Both compounds are economically interesting and have great possibility of future commercial applications.

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Rhodotorula spp. and Trichosporon spp. are opportunistic pathogens, and although an association between these two species in the same infection appears to be uncommon, it has been reported. This is the first study that aimed to evaluate the pathogenesis of a co-infection by R. mucilaginosa and T. asahii, using a new in vivo model, the Zophobas morio larvae. Suspensions from planktonic and biofilm-recovered cells were injected in the larvae as in monospecies as mixed (a ratio of 1:1 for both agents of a of 105 inoculum). Individual and mixed biofilms of R. mucilaginosa and T. asahii were produced for 24 and 48 h, and they were partially characterized by crystal violet and reduction of tetrazolium salt. When evaluating the impact of the planktonic suspension in vivo we verified that the fungi in monoculture were more able to kill the larvae than those from planktonic mixed suspension. On the other hand, regarding biofilm-recovered cells, there was an increase in the death of larvae infected for mixed suspensions. Moreover, the death rate was more pronounced when the larvae were infected with 48 h biofilm-recovered cells than the 24 h ones. T. asahii was the best producer of total biomass, mainly in 48 h. The metabolic activity for both yeasts organized in biofilm maintained the same pattern between 24 and 48 h. The present study proves a synergistic interaction between R. mucilaginosa and T. asahii after an experience in a mixed biofilm. Our results suggest that both species were benefited from this interaction, acquiring a greater potential for virulence after passing through the biofilm and this ability was acquired by the cells released from the biofilm.

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Mucositis is one of the most strenuous side effects caused by chemotherapy drugs, such as 5-fluorouracil (5-FU), during the treatment of several types of cancers. The disease is so prevalent and aggressive that many patients cannot resist such symptoms. However, despite its frequency and clinical significance, there is no effective treatment to prevent or treat mucositis. Thus, the use of probiotics as an adjuvant for the treatment has gained prominence. In the present study, we evaluated the effectiveness of oral administration of the Antarctic strain of Rhodotorula mucilaginosa UFMGCB 18,377 as an alternative to minimize side effects of 5-FU-induced mucositis in mice. Body weight, food consumption, stool consistency, and presence of blood in the feces were assessed daily in mice orally treated or not with the yeast and submitted or not to experimental mucositis. Blood, bones, and intestinal tissues and fluid were used to determine intestinal permeability and immunological, microbiological, and histopathological parameters. Treatment with R. mucilaginosa UFMGCB 18,377 was able to decrease clinical signs of the disease, such as reduction of food intake and body weight loss, and also decreased the number of intestinal enterobacteria and intestinal length shortening. Additionally, treatment was able to decrease the levels of MPO and EPO activities and inflammatory infiltrates, as well as the histopathological lesions characteristic of mucositis in the jejunum and ileum. Results of the present study showed that the oral administration of R. mucilaginosa UFMGCB 18,377 protected mice against mucositis induced by 5-FU.

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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

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The oleaginous yeast Rhodotorula toruloides is a potential lipid producer for biodiesel production. However, this yeast shows growth inhibition due to harmful compounds when cultivated in hemicellulose hydrolysate. Here, we present a comparative analysis of colony selection and heterologous adaptive laboratory enhancement (ALE) strategies for obtaining robust strains. We implemented these ALE strategies for R. toruloides in a culture medium containing sugarcane hemicellulose hydrolysate. Our comparison study showed that the strain obtained with heterogeneous ALE strategy (Rth) reached a µmax of 55% higher than the parental strain. It also exhibited higher biomass production (6.51 g/l) and lipid content (60%). ALE with colony selection strategy (Rtc) had a fitness gain in terms of shortening of the lag phase (9 h) when compared to Rth and parental strain (11.67, 12.33 h, respectively). When cultivated in Eucalyptus urograndis hemicellulose hydrolysate, the Rth strain achieved a high lipid content, 64%. Kinetics studies showed a strong effect of acetic acid as a repressor of xylose consumption during R. toruloides cultivation.Key points• Distinct adaptive laboratory strategies resulted in strains with different physiologies.• Heterologous adaptive laboratory enhancement provided the best results (fitness gain of 55% in µmax).• The Rth strain achieved a lipid content of 64.3% during cultivation in eucalyptus hemicellulose hydrolysate.

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Candida yeasts are the most frequent in the vaginal content. This yeast may be a normal microbiota but also causes candidiasis. In symptomatic cases, primary candidiasis (VVC) or recurrence (RVVC) can be considered. This study aims to compare the frequency and in vitro sensitivity profile of Candida species isolated in the vaginal content with the different stages of the presence of yeasts. A total of 258 non-pregnant patients with/without VVC were prospectively screened at a teaching Health Centre of the Faculty of Medicine, in the University of Sao Paulo. The vaginal isolates were identified by traditional and molecular methods. Yeasts were isolated in 160 women. 34% were asymptomatic, 34% with vulvovaginal candidiasis (VVC), and 32% recurrent vulvovaginal candidiasis (RVVC). C. albicans was the most frequent species with 50.1% (82/160), followed by C. parapsilosis 13.7%(22/160), C. glabrata 12.5% (20/160), and C. tropicalis (6.2%). Analysis by the group showed that, in the asymptomatic group, eight yeast species were isolated, C. albicans 44.5% (24/54), C. glabrata 20% (11/54), C. parapsilosis and Rhodotorula rubra being the most frequent. In the VVC group, 11 yeast species were identified. Most isolates were C. albicans 68.5% (37/54), C. tropicalis 7.5% (4/54), and C. parapsilosis 5.5% (3/54). In the RVVC group, ten species were identified, the most frequent being C. albicans 38.5% (20/52), C. parapsilosis 17% (9/52), C. glabrata 4% (8/52), and C. tropicalis 6% (3/52). Less frequent species, such as C. haemulonii and Trichosporon spp, were isolated in the VVC and RVVC groups, C. kefyr was isolated in the three groups studied, and Rhodotorula spp was isolated in the control and RVVC groups. Candida metapsilosis was present in two isolates from the RVVC group. Most isolates were considered sensitive to the tested antifungals. Less sensitivity was seen for caspofungin. In this study, we were able to verify that the most common species of yeasts found in vaginal secretion were isolated in the three groups studied; however, there was the diversity of species in VVC and RVVC. Cryptic species C. haemulonii and were isolated in symptomatic patients. High levels of MICs, some of the antifungals tested, in the control group, draw attention in the group of asymptomatic women. We would like to emphasize that this research aims to assist clinicians and gynecologists, as well as assist in the epidemiological studies of candidiasis, in our country, how to draw attention to the profile of sensitivity/resistance to antifungals.

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In this work, strains of Bacillus subtilis were inoculated in consortium with Rhodotorula mucilaginosa into spent soy oil as aiming to biological treatment and low-cost reuse. The microorganisms were previously isolated and selected for the lipolytic capacity of the alperujo residue generated during the processing of olive oil. For fermentation, bioassays containing Rhodotorula mucilaginosa isolated from alperujo and Candida rugosa CCMA 00371, both co-inoculated with Bacillus subtilis CCMA 0085 in medium containing (% w/v) 0.075 glucose and 0.375 (NH4)3 PO4 in 75 mL of water and 75 mL of spent soy oil. Despite the low biomass productivity, it has favorable characteristics to be used in animal feed supplementation. Spent soy oil was used as a carbon source proven by Bartha respirometer. The strains of R. mucilaginosa UFLA RAS 144 and B. subtilis CCMA 0085 are promising inoculants for oil degradation and can be applied in a waste treatment system.

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A set of four strains representing a novel basidiomycetous yeast species Rhodotorula sampaioana f. a., sp. nov. were isolated from two different habitats, subsurface waters of Lake Negra in Argentina, and the gut of a xylophagous termite in India. Phylogenetic analyses of LSU and ITS sequences showed that they belonged to the genus Rhodotorula of the order Sporidiobolales (subphylum Pucciniomycotina) and the closest known relative being R. kratochvilovae. The new species differed from R. kratochvilovae CBS 7436 (AF071436, AF444520) by nine nucleotide substitutions and one deletion (1.7 % sequence variation) in a 593 bp D1/D2 region, and by five nucleotide substitutions and three deletions (1.3 %) in a 592 bp ITS region, respectively. Several morphological and physiological differences were also observed between R. kratochvilovae and the strains obtained during this study. These data support the proposal of Rhodotorula sampaioana as a novel species, with CRUB 1124 as the holotype, CBS 10798 as ex-type, and NFCCI 4872 as an additional strain. The GenBank accession numbers of the LSU and ITS sequences of Rhodotorula sampaioana f. a., sp. nov. are EF595748 and MW879331. The MycoBank number is MB 838533.

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