Saccharomyces bulderi sp. nov., a yeast that ferments gluconolactone

An unknown yeast species was isolated from maize silage and was determined to be novel on the basis of morphological and physiological characteristics, nucleotide sequence of domain D1/D2 of LSU rDNA and from its electrophoretic karyotype. The name for the proposed new species is Saccharomyces bulderi Middelhoven, Kurtzman et Vaughan-Martini (type strain CBS 8638, NRRL Y-27203, DBVPG 7127). S. bulderi is closely related to S. barnettii and S. exiguus from which it can be distinguished by having a double vitamin requirement of biotin and thiamine and by no or slow aerobic growth on raffinose, a sugar that on the contrary is fermented rapidly. Gluconolactone is rapidly fermented with ethanol, glycerol and carbon dioxide being the main products.     

<Emphasis Type="Italic">Metschnikowia viticola</Emphasis> sp. nov., a new yeast species from grape

Two yeast strains, producing needle-shaped ascospores under suitable conditions, were isolated from grapes grown in Hungary. Based on these two strains, Metschnikowia viticola (type strain NCAIM Y.01705, CBS 9950, JCM 12561) is proposed as a new yeast species. Considering its phenotypic features, the restriction fragment patterns of 18S rDNA and the sequence of the D1/D2 domain of 26S rDNA, the proposed new species is closely related to Candida kofuensis.     

一株分离于工业污水池的耐碱酵母

目的:从新疆温泉县一个碱性工业污水处理池中分离并鉴定耐碱酵母菌。方法:用稀释平板法分离菌种,通过形态学观察、生理生化特征及26S rDNA D1/D2区基因序列分析鉴定菌种。结果:从水样中分离得到一株耐碱酵母菌,它们能在pH3.5~11.0,12%NaCl,4~45℃生长,经形态观察及生理生化特征鉴定为酵母属,对其26S rDNA 5’端D1/D2区基因序列进行了PCR扩增并测序,GenBank注册号为DQ132884,同源序列分析结果表明该序列与酿酒酵母(Saccharomyces cerevisiae)Sb4有99.8%的同源性,因此将其命名为酿酒酵母(Saccharomyces cerevisiae)XJU-2,该菌种已保藏于中国微生物菌种保藏委员会普通微生物中心(CGM-CC),保藏号为CGMCC No.2.3095。结论:XJU-2的最高耐碱值可达pH 11.0,而且酸碱耐受范围很大,性能明显优于国内外已报道的酿酒酵母菌种。     

内蒙古西部区酸粥中酵母菌的分离鉴定及优势菌分析

从内蒙古地区采集28份酸粥样品,从中分离出40株酵母菌,并对其进行了分子生物学鉴定和生物多样性分析。26S rDNA D1/D2区域 (600bp左右)碱基序列分析结果表明,酸粥中的酵母菌有Issatchenkia orientalis、Saccharomyces cerevisiae、Geotrichum sp.、Candida pararugosa、 Candida parapsilosis、Trichosporon asahii、Trichosporon coremiiforme、Clavispora lusitaniae和Candida tropicalis。经过分析,Issatchenkia orientalis(75%,Frequency percentage)为酸粥中的优势菌。     

新疆地区酸马奶中酵母菌的鉴定及其生物多样性分析

从新疆少数民族牧民家庭采集的28份传统工艺酿造酸马奶样品中分离出87株酵母菌,并对其进行了生理生化鉴定、分子生物学鉴定和生物多样性分析。生化试验结果表明,新疆地区酸马奶中的酵母菌为Saccharomyces unisporus(占总分离株的48.3%),Kluyveromyces marxianus(27.6%),Pichia membranaefaciens(15.0%)和Saccharomyces cerevisiae(9.2%)。选取其中的6株酵母菌和1株参考菌株,进行大亚基(26S)rDNA D1/D2区域(600bp左右)碱基序列分析,并通过GenBank进行同源序列搜索以确定各菌株的归属,进一步验证生理生化方法的正确性。从得到的结果中可以看出,S.unisporus和K.marxianus为新疆地区酸马奶中的优势菌。     

Candida easanensis sp. nov., Candida pattaniensis sp. nov. and Candida nakhonratchasimensis sp. nov., three new species of yeasts isolated from insect frass in Thailand

Six strains of anamorphic yeasts isolated from insect frass collected in several regions of Thailand were assigned to the genus Candida based on the conventional taxonomic criteria used for yeast classification. These strains have Q-7 as the major ubiquinone and are suggested to have close relationships to the genus Pichia. Three strains, ST-225, ST-228 and ST-229, have identical nucleotide sequences in the D1/D2 domain of 26S rDNA and are closely related to Pichia japonica, but differ by six nucleotides (1.1% ) from this species. These three strains are considered to represent a single new species, which is described as Candida easanensis sp. nov. Two strains, ST-311 and ST-320, have identical sequences in the D1/D2 domain and resemble Pichia veronae and Pichia fabianii but differ from them by nine nucleotides (1.6%) in D1/D2 sequences. The two strains are described as Candida pattaniensis sp. nov. The remaining strain, ST-37, is related to Pichia americana and Pichia bimundalis but differs by six(1.1%) and seven (1.2%) nucleotides from these species, respectively. This strain is described as Candida nakhonratchasimensis sp. nov.     

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。     

Two new anamorphic yeasts, Candida thailandica sp. nov. and Candida lignicola sp. nov., isolated from insect frass in Thailand

Two new yeast strains of the genus Candida were isolated from insect frass collected in Khao-Yai National Park, Nakhonrachasima, Thailand. Based on the morphological, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 domain of 26S rRNA gene, these two strains were found to represent two distinct undescribed species and were named Candida thailandica sp. nov. (ST-17 = BCC 7717(T) = NBRC 102562(T)=CBS 10 610) and Candida lignicola sp. nov. (ST-33 = BCC 7733(T) = NBRC 102564(T) = CBS 10612). In the D1/D2 domain of 26S rRNA gene, C. thailandica (GeneBank accession no. AY228491) differs from Candida tsuchiyae, the nearest species, in 66 nucleotide substitutions (10%) and C. lignicola (GeneBank accession no. AY845350) differs from Candida coipomoensis, the nearest species, in nine nucleotides (1.6%). These two new species are clearly distinguished from their closest species by the assimilation of several carbon compounds.     

Debaryomyces mycophilus sp. nov., a siderophore-dependent yeast isolated from woodlice

Four strains of an ascogenous yeast were isolated from the guts of the woodlice species Armadillidium vulgare (Latreille). This yeast differed from all known yeasts by its inability to grow in culture without the presence of a metabolite produced by some common soil fungi such as Cladosporium cladosporioides, Aspergillus alliaceus, and Penicillium spp. Phylogenetic analysis based on 18S rDNA and 26S rDNA (domain D1/D2) sequences indicated that the yeast represents a new taxon in the genus Debaryomyces. The new species Debaryomyces mycophilus is thus proposed. It was, furthermore, shown that the fungal metabolite necessary for growth of D. mycophilus did not provide the yeast with carbon, nitrogen or vitamins. The active compound was partially purified and it was shown that it is a siderophore used by the yeast as a source of iron. The addition of ferrichrome or high concentrations of FeCl(3) to growth media replaced the obligate dependence on a fungal metabolite. Symbiosis among fungi, based on the availability and utilization of iron, is an aspect of mycology that has not previously been recognized. The addition of chelated iron to isolation media could lead to the discovery of many unknown yeasts and fungi.     

Dimorphic cycle in Candida citri sp. nov., a novel yeast species isolated from rotting fruit in Borneo

Five dimorphic yeast strains were isolated from rotting lime fruits in Borneo. The sequences of the D1/D2 domains of the 26S rRNA genes, the internal transcribed spacer (ITS) chromosomal regions and the 18S rRNA genes were identical in the isolates and differed from the corresponding sequences of all known yeast species. Based on the sequence differences (12-15% in the D1/D2 domain) from the closest relatives and the different pattern of taxonomic traits, the new isolates are assigned the status of a new species, for which the name Candida citri sp. nov. is proposed. Its type strain is 11-469(T) , which has been deposited in Centralbureau voor Schimmelcultures (Utrecht, the Netherlands) as CBS 11858(T) , Culture Collection of Yeasts (Bratislava, Slovakia) as CCY 29-181-1(T) and the National Collection of Agricultural and Industrial Microorganisms (Budapest, Hungary) as NCAIM Y.01978(T) . MycoBank number: MB 519100. The GenBank accession numbers for nucleotide sequences of its D1/D2 domain, ITS and 18S regions are HM803241, HM803242 and HM803243, respectively. Candida citri produces invasive mycelium composed of true septate hyphae that grow towards nutrient-rich parts of the medium and develop large vacuoles at the nongrowing ends of their cells. The hyphae produce blastoconidia, which can establish satellite yeast colonies in the invaded solid substrate.     

<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.     

Candida queiroziae sp. nov., a cellobiose-fermenting yeast species isolated from rotting wood in Atlantic Rain Forest

Eight strains of a novel yeast species were isolated from rotting wood and wood-boring insects in Atlantic Rain Forest ecosystems in Brazil. Sequences of the D1/D2 domains of the large subunit of the rRNA gene showed that the yeast belongs to the Scheffersomyces clade and that it is related to Candida lignicola and Candida coipomoensis. The new species was isolated from rotting wood of three different localities and a wood-boring insect suggesting that these substrates are its ecological niche. This new yeast species is able to assimilate cellobiose and other compounds related to rotting wood. Strong fermentation of cellobiose in Durham tubes was observed for the strains of this new yeast. The new species produced an intracellular β-glucosidase responsible for cellobiose hydrolysis. The novel species, Candida queiroziae sp. nov., is proposed to accommodate these isolates. The type strain of C. queiroziae is UFMG-CLM 5.1(T) (=CBS 11853(T) = NRRL Y-48722(T)).     

Candida alocasiicola sp. nov., Candida hainanensis sp. nov., Candida heveicola sp. nov. and Candida musiphila sp. nov., novel anamorphic, ascomycetous yeast species isolated from plants

In a taxonomic study on the ascomycetous yeasts isolated from plant materials collected in tropical forests in Yunnan and Hainan Provinces, southern China, four strains isolated from tree sap (YJ2E(T)) and flowers (YF9E(T), YWZH3C(T) and YYF2A(T)) were revealed to represent four undescribed yeast species. Molecular phylogenetic analysis based on the large subunit (26S) rRNA gene D1/D2 domain sequences showed that strain YJ2E(T) was located in a clade together with Candida haemulonii and C. pseudohaemulonii. Strain YF9E(T) was most closely related to C. azyma and strain YWZH3C(T) to C. sorbophila and C. spandovensis. Strain YYF2A(T) was clustered in a clade containing small-spored Metschnikowia species and related anamorphic Candida species. The new strains differed from their closely related described species by more than 10% mismatches in the D1/D2 domain. No sexual states were observed for the four strains on various sporulation media. The new species are therefore assigned to the genus Candida and described as Candida alocasiicola sp. nov. (type strain, YF9E(T) = AS 2.3484(T) = CBS 10702(T)), Candida hainanensis sp. nov. (type strain, YYF2A(T) = AS 2.3478(T) = CBS 10696(T)), Candida heveicola sp. nov. (type strain, YJ2E(T) = AS 2.3483(T) = CBS 10701(T)) and Candida musiphila sp. nov. (type strain, YWZH3C(T) = AS 2.3479(T) = CBS 10697(T)).     

红富士苹果园酵母多样性研究

从北京顺义和山东泰安红富士苹果园采集果实、叶片、树皮和土壤等不同基物,分离酵母菌,利用26S rDNA的D1/D2区域序列分析并结合形态学特征和SSCP分析对这些菌株进行了分类学研究,探讨了苹果园酵母的物种多样性及其分布。北京苹果园共分离酵母菌129株,鉴定为13属21种,优势属为Pichia（4个种）,Cryptococcus（3个种）,Pseudozyma（3个种）,子囊菌占较大优势,分布于8属12种,占总种数的57.1%。山东苹果园共分离酵母291株,鉴定为13属26种,优势属为假丝酵母Candida（6个种）,毕赤酵母Pichia（4个种）和隐球酵母Cryptococcus（3个种）,并且子囊菌占较大优势,分布于7属17种,占总种数的65.4%。     

Gelidatrema psychrophila sp. nov., a novel yeast species isolated from an ice island in the Canadian High Arctic

A new cold-adapted yeast species, Gelidatrema psychrophila sp. nov., was isolated from a melt-pool microbial mat community, on an ice island located in Disraeli Fjord, Ellesmere Island, in the Canadian High Arctic. Molecular analysis of the D1/D2 domain sequence of the large subunit rDNA showed that this species is novel and could grow at sub-zero temperatures and in vitamin-free media. These characteristics were likely acquired by the yeast to survive in extreme, perennially cold oligotrophic environments.     

Occurrence and dominance of yeast species in naturally fermented milk from the Tibetan Plateau of China

To determine which yeasts are present in the naturally fermented milks of China, 69 samples made by the nomads of Tibet were collected from the Tibetan Plateau in China. From these samples, 225 strains of yeast were isolated and identified using conventional microbiological analysis and gene sequencing analysis of the D1/D2 domain of the large subunit (26S) ribosomal DNA. The results showed that the total concentration of yeasts in these samples ranged from 5.01 to 8.97 log10 colony-forming units (CFU)/mL (6.91?± 1.02 log10 CFU/mL; mean?± SD). The number of cultivable yeasts was higher in the samples from Qinghai (7.55?± 0.75 log10 CFU/mL) than those from Tibet (6.21?± 0.79 log10 CFU/mL, P?< 0.05). Moreover, there were 15 phylotypes in these 69 samples. Among these phylotypes, Kluyveromyces marxianus (49.3%, frequency percentage), Saccharomyces cerevisiae (62.3%), and Pichia fermentans (46.4%) appeared frequently and can be considered the most common culturable species in naturally fermented milk products. Traditional fermented Mongolian cow milk featured a wide diversity of yeast species, including Issatchenkia orientalis, Kazachstania unisporus, Rhodotorula mucilaginosa, Candida pararugosa, Torulaspora delbrueckii, Geotrichum sp., Kazachstania unisporus, Geotrichum fragrans, Debaryomyces hansenii, Yarrowia lipolytica, Trichosporon gracile, and Pichia membranifaciens. This study provides new data on yeast composition in naturally fermented milk and shows the yeast biodiversity of fermented milk products from the Tibetan Plateau of China.     

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%。     

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.     

Pichia nongkratonensis sp. nov., a new species of ascomycetous yeast isolated from insect frass collected in Thailand

A yeast strain isolated from insect frass collected in Thailand was found to represent a new species of the genus Pichia. It is described as Pichia nongkratonensis sp. nov. In the phylogenetic tree based on the D1/D2 domain sequences of 26S rDNA, this yeast constitutes a cluster with Pichia dryadoides with high bootstrap confidence level; however, it differs from the latter species by 5.6% base substitutions. Pichia nongkaratonensis resembles P. dryadoides also in the phenotypic characteristics but is distinguished from this species by the assimilation of several carbon and nitrogen compounds.