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).     

青海东部土壤中酵母物种多样性研究

从青海的互助、民和、门源等10个州县收集土样分离得到98株酵母菌, 利用26S rDNA D1/D2区域序列分析并结合形态学和生理生化特性对这些菌株进行了分类学研究, 探讨了青海东部土壤中酵母的物种多样性及其分布。共鉴定出10属13种(其中有两个疑似新种), 其中 Galactomyces geotrichum和Rhodotorula mucilaginosa为该地的优势种。     

<Emphasis Type="Italic">Rhodotorula oryzae</Emphasis> sp. nov., a novel basidiomycetous yeast species isolated from paddy rice

A basidiomyetous yeast strain RO-203, which formed orange-red colored colonies, was isolated from a sample of paddy rice crops at the ripe stage in Japan. Morphological, physiological and biochemical characterization indicated that this strain belonged to the genus Rhodotorula. Molecular taxonomic analysis based on the 26S rDNA D1/D2 domain and internal transcribed spacer (ITS) region sequences showed that RO-203 represents an undescribed yeast species, for which the name Rhodotorula oryzae sp. nov. is proposed (type strain: AS 2.2363^T = MAFF 516128^T). The new species clustered in a branch together with Sakaguchia dacryoidea in phylogenetic trees based on the D1/D2 and ITS sequences. These two species differed by 2.3% and 12% nucleotide divergences in the D1/D2 and ITS regions, respectively.     

Polyphasic taxonomy of the basidiomycetous yeast genus Rhodotorula: Rh. glutinis sensu stricto and Rh. dairenensis comb. nov

The phenotypic and genetic heterogeneity of the basidiomycetous yeast species Rhodotorula glutinis was investigated in a group of 109 isolates. A polyphasic taxonomic approach was followed which included PCR fingerprinting, determination of sexual compatibility, 26S and ITS rDNA sequence analysis, DNA-DNA reassociation experiments and reassessment of micromorphological and physiological attributes. The relationships with species of the teleomorphic genus Rhodosporidium were studied and isolates previously identified as Rh. glutinis were found to belong to Rhodosporidium babjevae, Rhodosporidium diobovatum and Rhodosporidium sphaerocarpum. Other isolates included in the study were found to belong to Rh. glutinis var. dairenensis, which is elevated to the species level, or to undescribed species. The concept of Rh. glutinis sensu stricto is proposed due to the close phenetic and phylogenetic proximity detected for Rh. glutinis, Rhodotorula graminis and R. babjevae.     

云南5个地区戟叶酸模花中酵母菌和类酵母的多样性

[目的]研究云南5个地区(晋宁、祥云、程海、泸沽湖、洱海)的戟叶酸模(Rumex hastatus)花中的酵母菌和类酵母.[方法]采用涂布平板法对5个地区的戟叶酸模花中酵母菌和类酵母进行分离,通过26S rDNA Dl/D2区域序列分析并结合形态观察对分离获得的酵母菌和类酵母进行鉴定;采用胞外酶定性筛选培养基进行产酶筛选;用苏丹黑B染色法筛选产油脂菌株.[结果]从戟叶酸模花中分离得到82株酵母菌和99株类酵母;82株酵母菌鉴定为6个属16个种和1个潜在新种,99株类酵母鉴定为短梗霉属(Aureobasidium)的普鲁兰类酵母(A.pullulans)及3个变种;戟叶酸模花中的优势属是类酵母短梗霉属,其次为红酵母属(Rhodotorula)和隐球酵母属(Cryptococcus);筛选到134株具有产胞外酶活性和83株产油脂的酵母菌和类酵母.[结论]研究结果显示5个地区的戟叶酸模花中酵母菌和类酵母种类多样性较为丰富,并具有产淀粉酶、蛋白酶、纤维素酶、脂肪酶和油脂的特点,有潜在的应用前景.     

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.)。     

Fermentation and aerobic metabolism of cellodextrins by yeasts

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

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.     

Fermentation and aerobic metabolism of cellodextrins by yeasts.

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

深红酵母相关菌株全细胞长链脂肪酸的分析及其数值分类

从黄海和渤海海水中分离到15株红酵母,初步定名为深红酵母(Rhodotorula rubraLodder)对这些菌株及另外8株红酵母属对照种的形态、生理生化性状以及全细胞长链脂肪酸的组成进行了测定,并用多元统计方法对菌株间的相似性进行了计算,对菌株分群。结果表明,15株酵母之间性状存在许多差异,这些差异不能完全被鉴定性状所反映,在多元分析中15株菌不能形成紧密的聚类群。研究结果对利用个别形态和生理生化性状确定的深红酵母种的范围提出了异议。     

Distribution of aspartate aminotransferase activity in yeasts, and purification and characterization of mitochondrial and cytosolic isoenzymes from Rhodotorula minuta [corrected

The distribution of aspartate aminotransferase activity in yeasts was determined. The number of species of the enzyme in each yeast was determined by zymogram analysis. All the yeasts, except for the genus Saccharomyces, showed two or three activity bands on a zymogram. From among the strains, Rhodotorula minuta [corrected] and Torulopsis candida were selected for examination of the existence of yeast mitochondrial isoenzymes, because these strains showed two clear activity bands on the zymogram and contained a high amount of the enzyme. Only one aspartate aminotransferase was purified from T. candida: the component in the minor band on the zymogram was not an isoenzyme of aspartate aminotransferase. On the other hand, two aspartate aminotransferases were purified to homogeneity from R. minuta [corrected]. The components in the main and minor activity bands on the zymogram were identified as the mitochondrial and cytosolic isoenzymes, respectively, in a cell-fractionation experiment. The enzymatic properties of these isoenzymes were determined. The yeast mitochondrial isoenzyme resembled the animal mitochondrial isoenzymes in molecular weight (subunits and native form), absorption spectrum, and substrate specificity. The amino acid composition was closely similar to that of pig mitochondrial isoenzyme. Rabbit antibody against the yeast mitochondrial isoenzyme, however, did not form a precipitin band with the pig mitochondrial isoenzyme.     

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

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

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

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

Identity and biodegradative abilities of yeasts isolated from plants growing in an arid climate

Plants harvested in the Canary Islands Lanzarote and Fuerteventura were analyzed for the yeasts inhabiting their surface. Half of the isolates (22 out of 44) were identified as Debaryomyces hansenii. Black ascomycetes, viz. Hortaea werneckii and two Hormonema species were represented by 7 strains. Basidiomycetous yeasts, viz. Cryptococcus sp. (8 strains), Rhodotorula sp. (5 strains), Cerinosterus cyanescens (1 strain) and Pseudozyma sp. (1 strain) constituted a minority of 33%. Thirty strains were screened for their ability to assimilate various plant constituents including lipids of the cuticle and the cell membrane, hemicelluloses, nitrogenous compounds (protein, nucleic acids, amino acids) and benzene compounds. All strains were able to assimilate or to hydrolyze lipids, lecithin included. Many strains of D. hansenii, H. dematioides, H. werneckii, C. cyanescens, Cr. laurentii, Pseudozyma sp. and Rh. glutinis were proteolytic. Hemicelluloses like xylan and pectin were assimilated by black ascomycetous yeasts, Cryptococcus sp., Pseudozyma sp. and Rh. glutinis. Ferulic and hydroxycinnamic acids, gallic and tannic acids were assimilated by some strains of H. dematioides, C. cyanescens, Pseudozyma sp. and Rhodotorula sp.     

Yeast populations on the tropical timber tree species Milicia excelsa

H. LI, E. VEENENDAAL, N.A. AB SHUKOR, J.R. COBBINAH AND C. LEIFERT. 1995. Yeast populations found on the tropical timber tree species Milicia excelsa showed very little diversity at the genus and species level. Of 62 isolates, 87% were Cryptococcus laurentii , 5% Candida humicola , 3% Candida curvata , 1.5% Candida membranaefaciens , 1.5% Rhodotorula minuta and 1.5% Rhodotorula rubra . Approximately half of the Crypt. laurentii strains had unusual metabolic profiles when compared with the Crypt. laurentii strains in the profile library of the APILAB yeast identification software. All isolated strains were non-pathogenic and did not show antagonism against Botrytis cinerea in an in vitro plate assay. However, three strains of Crypt. laurentii suppressed disease development of B. cinerea in a leaf disk bio-assay. This indicates that protection of leaves against opportunistic fungal diseases may be part of the ecological function of Crypt. laurentii populations on Milicia leaves and the potential of this yeast species for biological control.     

Genetic analysis of D-xylose metabolism by endophytic yeast strains of Rhodotorula graminis and Rhodotorula mucilaginosa

Two novel endophytic yeast strains, WP1 and PTD3, isolated from within the stems of poplar (Populus) trees, were genetically characterized with respect to their xylose metabolism genes. These two strains, belonging to the species Rhodotorula graminis and R. mucilaginosa, respectively, utilize both hexose and pentose sugars, including the common plant pentose sugar, D-xylose. The xylose reductase (XYL1) and xylitol dehydrogenase (XYL2) genes were cloned and characterized. The derived amino acid sequences of xylose reductase (XR) and xylose dehydrogenase (XDH) were 32%～41% homologous to those of Pichia stipitis and Candida. spp., two species known to utilize xylose. The derived XR and XDH sequences of WP1 and PTD3 had higher homology (73% and 69% identity) with each other. WP1 and PTD3 were grown in single sugar and mixed sugar media to analyze the XYL1 and XYL2 gene regulation mechanisms. Our results revealed that for both strains, the gene expression is induced by D-xylose, and that in PTD3 the expression was not repressed by glucose in the presence of xylose.     

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).     

秦岭地区子囊菌酵母物种多样性研究

从陕西秦岭地区的果实和叶等不同基物上分离得到子囊菌酵母262株,利用26SrDNA的D1/D2区域序列分析并结合形态学特征对这些菌株进行了分类学研究,探讨了该地区子囊菌酵母的物种多样性及其分布。共鉴定出10属31种,其中优势属为假丝酵母属Candida,12种,(其中新种2个,另文发表)、酿酒酵母属Saccharomyces,5种、毕赤酵母属Pichia,5种和有孢汉逊酵母属Hanseniaspora,3种。对分离自陕西秦岭不同地区与海拔的同一个种的不同菌株进行了D1/D2序列分析比较,以探讨子囊菌酵母种内序列稳定性和变异幅度。     

26S rDNA单链构象多态性分析在临床酵母菌菌种鉴定中的应用

摘要： 【目的】探讨酵母菌临床分离株26S rDNA D1/D2区序列种内相似性和种间差异性的快速检测方法,为临床酵母菌菌种鉴定方法的改进奠定基础。调查北京地区临床酵母菌的种群多样性,为国内酵母菌感染的流行病学研究提供新的基础数据。【方法】用5种常见临床酵母菌种的模式和权威菌株作为标准参考菌株,从北京四家综合性医院收集临床酵母菌260余株,PCR扩增其26S rDNA D1/D2区,对扩增产物进行单链构象多态性（Single-Strand Conformation Polymorphism,SSCP）分析和序列测定分析。【结果】常见病原酵母菌26S rDNA D1/D2区的SSCP图谱具有明显的种间差异性和种内相似性,可以通过该方法对菌株进行初步的菌种鉴定。D1/D2-SSCP和序列分析相结合,对260余株临床酵母菌进行了菌种鉴定,共鉴定有10个属20个种,优势属为念珠菌属(Candida),优势种及其所占比例分别是：C. albicans (57.7%), C. parapsilosis (10.0%), C. tropicalis (9.2%), C. glabrata (6.7%)和C. krusei (5.8%),并发现过去从未或很少报道致病的酵母菌种,愈来愈多地出现在临床分离菌株中。【结论】 26S rDNA D1/D2区的SSCP图谱分析为临床酵母菌株的快速鉴定提供了新的方法;北京地区酵母菌临床分离株呈种群多样性分布,C. albicans虽然仍占优势,但其它念珠菌种的比例已达42%。