Rhodotorula infection. A systematic review of 128 cases from literature

Rhodotorula is an emerging opportunistic pathogen, particularly in immunocompromised patients. Many cases of fungemia associated with catheters, endocarditis, peritonitis, meningitis, and endophthalmitis are infections incited by this yeast. The main purpose of this study was to review all cases of Rhodotorula infection reported in the literature and to describe risk factors, underlying conditions and outcome. From 128 cases, 79% were fungemia (103 cases), 7% eye infections (nine cases) and 5% (six cases) peritonitis associated with continuous ambulatory peritoneal dialysis. Eighty seven percent of Rhodotorula infections are associated with underlying immunosuppression or cancer. The most common isolated risk factor associated with Rhodotorula infection was the use of a central venous catheter, which was found in 83.4% of Rhodotorula fungemia (86 cases). Rhodotorula mucilaginosa was the most common species of fungemia (74% of cases), followed by Rhodotorula glutinis with 7.7%. The species was not identified in 17% of the cases of fungemias. Amphotericin was the drug of choice in the treatment of fungemia and most of the eye infections were treated with topical amphotericin, although all patients lost their vision. All peritonitis cases associated with continous ambulatory peritoneal dialysis needed to have the Tenckoff catheter changed. The overall mortality of Rhodotorula infection was 12.6%.     

Rhodotorula Fungemia of an Intensive Care Unit Patient and Review of Published Cases

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

Fatty acid makeup of the lipids in soil and epiphytic yeasts]

The fatty acid composition of lipids was compared among yeast cultures belonging to the genera Rhodotorula, Lipomyces, and Cryptococcus. These lipids contain C10--C26 fatty acids, mainly with the even number of carbon atoms. Palmitic acid (C16 : 0) and oleic acid (C18 : 0) predominate. In the majority of the strains, the sum of unsaturated acids exceeds the sum of saturated acids. The content of unsaturated acids in the lipids of the epiphytic yeast Rhodotorula is higher than in the soil yeast Lipomyces. Besides C12--C18 acids, C22--C26 acids were identified by GLC at preset temperatures. Lignoceric acid (C24 : 0) was found for the first time in the cultures of Rhodotorula, Lipomyces, and Cryptococcus, and cerotinic acid (C16 : 0) was also detected in the Rhodotorula yeast. Fatty acids with a long chain are registered in the strains of Rhodotorula more often than in the strains of Lipomyces and Cryptococcus.     

Psychrophilic yeasts in glacial environments of Alpine glaciers

The presence of psychrophilic yeasts in supra- and subglacial sediments, ice and meltwater collected from two glaciers of the Italian Alps (Forni and Sforzellina-Ortles-Cevedale group) was investigated. After incubation at 4 degrees C, subglacial sediments contained from 1.3 x 10(3) to 9.6 x 10(3) CFU of yeasts g(-1). The number of yeast cells in supraglacial sediments was c. 10-100-fold lower. A significant proportion of isolated yeasts exhibited one or more extracellular enzymatic activities (starch-degrading, lipolytic, esterolytic, proteolytic and pectinolytic activity) at 4 degrees C. Selected isolates were able to grow at 2 degrees C under laboratory-simulated in situ conditions. In all, 106 isolated yeasts were identified by MSP-PCR fingerprinting and 26S rRNA gene sequencing of the D1/D2 region as belonging to 10 species: Aureobasidium pullulans, Cryptococcus gilvescens (over 50% of the total), Cryptococcus terricolus, Mrakia gelida, Naganishia globosa, Rhodotorula glacialis, Rhodotorula psychrophenolica, Rhodotorula bacarum, Rhodotorula creatinivora and Rhodotorula laryngis. Four strains, all belonging to a new yeast species, yet to be described, were also isolated.     

红酵母属中的一个新种

自云南省哀牢山常绿阔叶林根际土壤中分离出一株酵母菌Ⅱ-33。该菌株细胞卵圆,出芽时胞壁结构为内分芽型,多端芽殖,不产生子囊孢子和掷孢子;在麦芽汁琼脂上产生红色胡萝卜素,颜色反应阳性,菌落平滑,有光泽,质地软而呈粘液状,不发酵任何糖,能同化麦芽糖、蔗糖、乳糖、棉子糖、松三糖和硝酸钾,能分解尿素;细胞水解物中含甘露糖、葡萄糖和半乳糖。按其形态、培养特征和生理生化特性,酵母菌Ⅱ-33应归入红酵母属(Rhodotorula)中,经与近似种比较,认为是红酵母属中的一个新种,命名为云南红酵母(Rhodotorula yunnanensis sp.n.)。     

Transport and metabolism of 2-deoxy-D-glucose by Rhodotorula glutinis

2-Deoxy-D-glucose transport by Rhodotorula glutinis is an active process. The intracellular concentration of free deoxyglucose after 15 min incubation of Rhodotorula cells with this sugar was 230 times the extracellular concentration. Although cell extracts at this time contained more 2-deoxy-D-glucose 6-phosphate than deoxyglucose, pulse-labelling experiments demonstrated that deoxyglucose is transported as the free sugar and subsequently phosphorylated. After transport, Rhodotorula cells metabolize deoxyglucose. The major metabolites during 30-90 min incubations were determined to be 2-deoxy-D-glucose 6-phosphate, 2-deoxy-D-glucitol, 2-deoxy-D-gluconate and 2,2'-dideoxy-alpha, alpha'-trehalose. Rhodotorula glutinis also degrades deoxyglucose to CO2. The concentrations of intermediates in this pathway were too low to detect and resolve in extracts of control cells. In 2,4-dinitrophenol-poisoned cells, however, it appears that deoxyglucose degradation is restricted largely to loss of C-1 as CO2 and it was possible to identify 1-deoxy-D-ribulose 5-phosphate as an intermediate presumably arising from metabolism of deoxyglucose by the oxidative portion of the hexose monophosphate pathway.     

红酵母的抗氧化机制与高产类胡萝卜素菌株的筛选*

通过聚丙烯酰胺凝胶电泳(PAGE)和超氧化物歧化酶(SOD)的鉴别性定位染色分析,表明红酵母Rhodotorula sp.仅存在线粒体中的Mn-SOD。在类胡萝卜素含量较高的时期(培养5d),红酵母SOD活力下降, 过氧化氢酶(CAT)活力升高,而此时它对外界O2-. 和H2O2的抗性均明显高于类胡萝卜素含量较低的时期(培养2d)。以上结果表明红酵母胞质中的抗氧化作用已主要由类胡萝卜素来承担,类胡萝卜素含量越高,红酵母抗氧化能力越强。由此,利用产生的O2-. 试剂TBO处理红酵母,可筛选出稳定高产的类胡萝卜素菌株,其中以培养2d的红酵母作为筛选对象更佳,所筛菌落类胡萝卜素含量可高达1740.9~2039.2g/g干重,比未处理的对照增加了28.2%~50.1%。     

Rhodotorula infirmo-miniata (Okunuki) comb. n.

Torula infirmo-miniata Okunuki was taxonomically compared withRhodotorula macerans Sonne-Frederiksen. As these two yeasts proved to be very closely related, it is proposed to incorporate both in a new combination,Rhodotorula infirmo-miniata.     

两相分配法制备南极红酵母质膜

用葡聚糖 T-500(Dextran T-500)和聚乙二醇(PEG-3350)两相体系制备南极红酵母(Rhodotorula sp.)菌株 NJ298 的质膜.首先在 2 mmol/L KCl 浓度下,选用5种不同的聚合物浓度(5.6%、5.8%、6.0%、6.2%、6.4%,W/W),研究了 NJ298 质膜在两相体系中的分配情况,在此基础上进一步研究了 KCl 浓度(2 mmol/L、4 mmol/L、6 mmol/L、8 mmol/L、10 mmol/L)对 NJ298 质膜的纯度及得率的影响.结果表明,选用6.0%聚合物浓度,4 mmol/LKCl 的两相分配体系,分离3次可得到相对纯度在 78.2%的南极红酵母质膜组分,标志酶鉴定及磷钨酸染色电镜检测均表明获得了高纯度密实的正向型的质膜囊泡.这为进一步研究该菌株的南极极端环境适应机制奠定了基础.     

两相分配法制备南极红酵母质膜

用葡聚糖T-500(Dextran T-500)和聚乙二醇(PEG-3350)两相体系制备南极红酵母(Rhodotorula sp.)菌株 NJ298的质膜。首先在2 mmol/L KCl浓度下, 选用5种不同的聚合物浓度(5.6%、5.8%、6.0%、6.2%、6.4 %, W/W), 研究了NJ298质膜在两相体系中的分配情况, 在此基础上进一步研究了KCl浓度(2 mmol/L、4 mmol/L、6 mmol/L、8 mmol/L、10 mmol/L)对NJ298质膜的纯度及得率的影响。结果表明, 选用6.0%聚合物浓度, 4 mmol/L KCl的两相分配体系, 分离3次可得到相对纯度在78.2%的南极红酵母质膜组分, 标志酶鉴定及磷钨酸染色电镜检测均表明获得了高纯度密实的正向型的质膜囊泡。这为进一步研究该菌株的南极极端环境适应机制奠定了基础。     

The identification and characterization of osmotolerant yeast isolates from chemical wastewater evaporation ponds

Ramat Hovav is a major chemical industrial park manufacturing pharmaceuticals, pesticides, and various aliphatic and aromatic halogens. All wastewater streams are collected in large evaporation ponds. Salinity in the evaporation ponds fluctuates between 3% (w/v) and saturation and pH values range between 2.0 and 10.0. We looked for microorganisms surviving in these extreme environmental conditions and found that 2 yeast strains dominate this biotope. 18S rDNA sequence analysis identified the isolates as Pichia guilliermondii and Rhodotorula mucilaginosa. Both isolates grew in NaCl concentrations ranging up to 3.5 M and 2.5 M, respectively, and at a pH range of 2-10. There was a distinct difference between the Rhodotorula and Pichia strains and S. cerevisiae RS16 that served as a control strain with respect to accumulation of osmoregulators and internal ion concentrations when exposed to osmotic stress. The Pichia and Rhodotorula strains maintained high glycerol concentration also in media low in NaCl. Utilization of various carbon sources was examined. Using a tetrazolium-based assay we show that the Rhodotorula and Pichia strains are capable of utilizing a wide range of different carbon sources including anthracene, phenanthrene, and other cyclic aromatic hydrocarbons.     

Production of biotin by yeasts

A quantitative screening procedure for biotin and biotin vitamer production was conducted on 129 yeast strains able to grow in a biotin-free medium. Production of biotin and biotin vitamers varied considerably from strain to strain even within a species. The best producers of biotin were strains of Sporobolomyces roseus and Rhodotorula rubra whilst strains of Rhodotorula rubra and Yarrowia lipolytica produced the largest amounts of vitamers.     

Glycolic acid production using ethylene glycol-oxidizing microorganisms.

Screening for microorganisms oxidizing ethylene glycol to glycolic acid was carried out. Among stock cultures, several yeasts and acetic acid bacteria showed high glycolic acid producing activity. Pichia naganishii AKU 4267 formed the highest concentration of glycolic acid, 35.3 g/l, from 10% (v/v) ethylene glycol (molar conversion yield, 26.0%). Among soil isolates, Rhodotorula sp. 3Pr-126, isolated using propylene glycol as a sole carbon source, formed the highest concentration of glycolic acid, 25.1 g/l, from 10% (v/v) ethylene glycol (molar conversion yield, 18.5%). Rhodotorula sp. 3Pr-126 showed higher activity toward 20% (v/v) ethylene glycol than P. naganishii AKU 4267. Optimization of the conditions for glycolic acid production was investigated using P. naganishii AKU 4267 and Rhodotorula sp. 3Pr-126. Under the optimized conditions, P. naganishii AKU 4267 and Rhodotorula sp. 3Pr-126 formed 105 and 110 g/l of glycolic acid (corrected molar conversion yields, 88.0 and 92.2%) during 120 h of reaction, respectively.     

Rhodotorula pinicola sp. nov., a basidiomycetous yeast species isolated from xylem of pine twigs

Three pink-colored yeast strains 3-1-3, 10-3-3 and 19-3-3 were isolated from xylem of surface-sterilized twigs of Pinus tabulaeformis collected from Dongling Mountain, Beijing, in different seasons. These strains were identified as Rhodotorula minuta (Saito) F.C. Harrison by conventional taxonomic characterization. However, molecular phylogenetic analysis based on internal transcribed spacer region (including 5.8S rDNA) and large-subunit rDNA D1/D2 domain sequences indicated that they represent a novel basidiomycetous yeast species, for which Rhodotorula pinicola is proposed (type strain: AS 2.2193(T)=CBS 9130(T)). The new species was most closely related to Rhodotorula laryngis Reiers?l in the R. minuta complex.     

Hydrolytic kinetic resolution of the enantiomers of the structural isomers trans-1-phenylpropene oxide and (2,3-epoxypropyl)benzene by yeast epoxide hydrolase

Kinetic resolution of the enantiomers of trans -1-phenylpropene oxide and (2,3-epoxypropyl)benzene was achieved by yeasts from the genus Rhodotorula. The resolution of trans -1-phenylpropene oxide by Rhodotorula glutinis UOFS Y-0123 yielded (1R,2R)-epoxide (ee >98%, yield 30%) and (1R,2S)-diol (ee 95%, yield 40%). The highest enantio- and regioselectivity toward (2,3-epoxypropyl)benzene resided in Rhodotorula sp. UOFS Y-0448 (E = 6.16), yielding (S)-epoxide (ee 64%, yield 33%) and (R)-diol (ee 67%, yield 28%). This confirms the superiority of yeasts from the Basidiomycetes genera in the enantioselective hydrolysis of epoxides from different structural classes.     

Production of Egg Yolk Coloring Material by a Fermentation Process

Rhodotorula mucilaginosa was cultivated in a yeast propagator, for the production of biomass and carotenoids. A spray-dried preparation of the yeast was incorporated into the diets of laying chickens for the promotion of egg yolk color. Several aspects of the effect of media on growth and carotenogenesis of pigmented yeast were examined. Addition of 1 to 2% of Rhodotorula yeast to the feeding mixture considerably improved egg yolk color. The possibility of using carotenogenic yeasts as a feed supplement is suggested.     

Reinstatement of Rhodotorula colostri (Castelli) Lodder and Rhodotorula crocea Shifrine & Phaff, former synonyms of Rhodotorula aurantiaca (Saito) Lodder

Rhodotorula aurantiaca (Saito) Lodder is an anamorphic basidiomycetous yeast species that belongs to the so-called "Erythrobasidium lineage" of the Urediniomycetes, according to molecular phylogenetic studies based on nucleotide sequence analyses of different ribosomal DNA regions. In the most recent editions of the yeast taxonomy treatises the species Rhodotorula colostri (Castelli) Lodder and Rhodotorula crocea Shifrine & Phaff were listed as synonyms of R. aurantiaca. Taxonomic heterogeneity within R. aurantiaca was demonstrated in a study based on whole-cell protein profiles and is also hinted at by the observed differences in physiological and biochemical characteristics among the different strains under that species name. We determined partial nucleotide sequences of the 26S rRNA gene (D1/D2 domains) of strains maintained in the CBS culture collection under R. aurantiaca, including the type strains of its synonyms. The results showed that R. colostri and R. crocea are clearly distinct from R. aurantiaca and from any other currently recognised basidiomycetous yeast species. Furthermore, phylogenetic analysis of the sequence data placed the former two species in separate lineages of the Microbotryomycetidae: R. colostri in the "ruineniae clade" (Sporidiobolus lineage or Sporidiobolales) and R. crocea loosely linked to Rhodotorula javanica (Microbotryum lineage).     

Lecithinase activity of various yeast strains]

The activity of lecithinase was studied among 50 yeast strains belonging to the genera Rhodotorula Harrison, Cryptococcus Kütz, and Lipomyces Lodder et Kreger van Rij. The maximum activity of lecithinase is typical of epiphyte yeast strains belonging to the genus Rhodotorula and is not manifested by species of the henus Lipomyces which inhabit soil. Strains of the genus Cryptococcus cannot be distinctly differentiated into soil and epiphyte cultures, and occupy an intermediate position by the activity of lecithinase.     

利用蔗渣半纤维素水解液产油酵母的筛选、鉴定及发酵实验

对已分离到的产油酵母通过木糖摇瓶发酵,从中筛选到2株H2-1和J2-2利用蔗渣半纤维素水解液高产油脂酵母,其利用蔗渣半纤维素水解液油脂得率系数分别为13.49和10.28,均显示出对蔗渣半纤维素水解液的高转化率.根据常规生理生化特征和26S rDNA序列分析结果,确认H2-1为小红酵母(Rhodotorula minuta),J2-2为粘红酵母(Rhodotorula glutinis).