假丝酵母属疑难菌株大亚基rDNAD1／D2区域序列分析及其分类学意义

对根据常规形态和生理生化性状难以确定分类学地位的8株假丝酵母菌,进行了以大亚基（26S）rDNA中D1/D2区域（均500-600bp)的碱基序列分析为依据的分子分类学研究。根据系统树上所显示的供试菌株与假丝酵母属及相关子囊菌酵母已知种的亲缘关系,以及与最近缘种模式菌株D1/D2区域序列的相似性比较,确定了各个菌株的归属,本研究也显示了DNA序列分析在假丝酵母菌快速鉴定中的优越性。     

耐高渗压高产甘油的一个假丝酵母新种——产甘油假丝酵母

从自然标本中分离获得一高产甘油的菌株WL20025,仅发酵葡萄糖及微发酵蔗糖,能利用葡萄糖、蔗糖、乙醇生长,微利用甘油和柠檬酸,不利用肌醇、硝酸盐、赤藓醇、阿拉伯醇、甘露醇,与DBB显色反应为阴性,可在含500g/L葡萄糖或100mL/L醋酸的培养基中及40℃下生长,可在水活度为0890～0900的培养基中生长,出芽生殖,易形成“假丝酵母菌型”假菌丝,不进行有性生殖,线粒体DNA的分子量为20kb,是假丝酵母属的一个新种,定名为产甘油假丝酵母(Candida glycerolgenesis Zhuge[WTBZ] sp.nov.)。     

产D-阿拉伯醇菌株的筛选、鉴定及其产D-阿拉伯醇条件的优化

摘要：【目的】产D-阿拉伯醇的耐高渗酵母的筛选、鉴定和产D-阿拉伯醇条件的优化。【方法】通过电镜、Biolog GN、(G+C)含量和26S rDNA D1/D2区序列分析法对所获得的菌株进行了描述。通过红外光谱、核磁共振氢谱和碳谱、质谱以及旋光度实验鉴定纯化产物的结构。通过单因素实验优化产D-阿拉伯醇的发酵条件。【结果】本文筛选得到一株产D-阿拉伯醇的新型菌株,经鉴定属于假丝酵母属并命名为Candida sp. H2。200 mL摇瓶发酵生产D-阿拉伯醇的单因素优化实验表明,最适发酵条件为：葡萄糖250     

克鲁斯假丝酵母及其近似种的脉冲电泳核型分析

用钳位均匀电场脉冲电泳(CHEF)系统分析了克鲁斯假丝酵母(Candida krusei),郎比可假丝酵母(C. lambica)和粗状假丝酵母(C. valiad)的模式菌株的电泳核型,发现这三种表型相似的假丝酵母却具有互不相同的染色体DNA分子带型,为其分类学研究提供了可靠的鉴别依据。在常规分类学研究的基础上,测定了AS 2.75(原定种名为(C. incospicua),AS2.1182(原定种名为 C. lambica)和AS 2.1772(未定种)等三株假丝酵母的G+C含量和脉冲电泳核型。通过对已报道的C. inconspicu的G+C含量及上述三种假丝酵母模式菌株的脉冲电泳核型的比较分析证明,AS 2.75和AS 2.1772为粗状假丝酵母(C. valida),AS 2.1182为克鲁斯假丝酵母(C. krusei)。     

三个发表于国内的丝孢酵母种名分类地位的订正*

最新的酵母菌分类系统,丝孢酵母属Trichosporon Behrend仅限于产生节孢子的担子菌酵母的无性型。因此,以前根据该属旧的定义在国内发表的三个新种板仓丝孢酵母T. bancangense、北京丝孢酵母T. beijingense和中国丝孢酵母T. sinense的分类地位,需要进行调整。根据26S rDNA D1/D2区的序列分析和最新标准方法重新测定的生理生化反应,发现上述三个种名分别是子囊菌酵母Saccharomycopsis fibuligera, Pichia burtonii和Issatchenkia orientalis的异名。     

一株高效利用木糖的酵母菌的分离及鉴定

从256个自然试样中筛选到1株高效转化D-木糖为木糖醇的酵母菌株441-28—1。初始木糖质量浓度为90g/L的条件下,24h内的木糖利用效率为3．0g／（L·h）。通过高效液相分析,菌株441-28—1的主要代谢产物为木糖醇。在初始木糖质量浓度为65g/L的条件下,摇瓶分批发酵,木糖醇生成速率达1．1g／（L·h）,木糖醇转化率为70％。经过形态、生理生化特征测定,以及ITS序列分析（GenBank的登记号为EU121523）,将441-28—1菌株鉴定为热带假丝酵母（Candida tropicalis）。Candida tropicalis（热带假丝酵母）已保存于中国高校工业微生物资源数据平台,保藏编号CICIM Y0092。     

西藏栉甲属三新种记述(鞘翅目,拟步甲科,朽木甲亚科)

对中国西藏栉甲属Cteniopinus Seidlitz进行了分类整理,给出已知种检索表,描述3新种,即:半圆栉甲C.semicirculoris sp.nov.,察隅栉甲C.zayicussp.nov.和黑缘栉甲C.nigriepipleuron sp.nov.。模式标本均保存在河北大学博物馆。半圆栉甲,新种Cteniopinus semicirculoris sp.nov.(图1～12,33～34)新种与黄须栉甲Cteniopinus flavipalpulus Baiet Ren,2004相似,但可由下列特征与之区别:个体明显大,体长11.1～12.4mm;前胸背板几乎半圆形;上唇前缘近直。正模♂,西藏察隅下察隅,1500～1580m,2005-07-12,石爱民采。副模:2♂♂,2♀♀,记录同正模;2♂♂,2♀♀,西藏察隅下察隅,1500～1580m,2005-07-11,石爱民采;2♂♂,2♀♀,西藏察隅上察隅,1700～2000m,2005-07-14,石爱民采。词源:新种种名以前胸背板几呈半圆形而拟定。察隅栉甲,新种Cteniopinus zayicus sp.nov.(图13～22,35)新种...     

3-羟基丙酸高产菌株的筛选及诱变选育

【目的】3-羟基丙酸是一种重要的化学平台化合物,期望得到一株能够高产3-羟基丙酸的菌株。【方法】从土壤及粪便筛选并对得到的菌株进行鉴定和复合诱变。【结果】得到了一株能够利用丙酸发酵生产3-羟基丙酸的酵母Y-11,经生理生化鉴定及18S rDNA序列分析确定其为Candida sp.(假丝酵母)。以Y-11为出发菌株,经紫外-亚硝基胍-60Coγ复合诱变得到了突变性状稳定且可遗传的高产菌株5-13B,其3-羟基丙酸的产量为11.78 g/L,是出发菌株的2.46倍。【结论】对出发菌株和突变株的发酵特性进行了比较,结果表明突变株的3-羟基丙酸产量、对底物丙酸的转化率、产物3-羟基丙酸的积累性能及丙酸的耐受性均优于出发菌株。     

大亚基rRNA基因D1/D2区序列相同或相似的子囊菌酵母ITS序列比较和核型分析

下面每个组内的酵母菌:I)Candida aaseri和Candida butyri;Ⅱ)Candida boleticola, Candida laureliae和Candida ralunensis;Ⅲ) Candida zeylanoides和Candida krissii以及Ⅳ) Pichia farinosa和Candida cacaoi因具有相同或只有一个碱基差异的大亚基(26S)rRNA基因D1/D2区序列,而被认为属于同一个种。本研究对其ITS序列和电泳核型进行了比较分析。结果表明前3个组内的种具有完全相同的ITS序列,第Ⅳ组的两个种只有1个碱基差异, 但是各组内的核型并不完全一致。第Ⅳ组内的两个种具有完全相同的核型,证实他们属于同一个种。第Ⅱ组内的C.laureliae和C.ralunensis也具有完全相同的核型,可以肯定二者也属于同一个种,该组内的C.boleticola的核型与前二者不完全一样,但染色体分子量范围相似,也可能与前二者属于同一个种。第Ⅰ和Ⅲ组内各种的核型具有明显差异,对组内种间的同物异名关系未提供支持。     

三个发表于国内的丝孢酵母种名分类地位的订正

最新的酵母菌分类系统,丝孢酵母属Trichosporon Behrend仅限于产生节孢子的担子菌酵母的无性型。因此,以前根据该属目的定义在国内发表的三个新种板仓丝孢酵母T.bancangense,北京丝孢酵母T.beijingense和中国丝孢酵母T.sinense的分类地位,需要进行调整。根据26SrDNA/D 1/D2区的序列分析和最新标准方法重新测定的生理生化反应,发现上述三个种名分别是子囊菌酵母Saccharomycopsis fibuligera,Pichia burtonii和Issatchenkia orientalis的异名。     

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)).     

Candida potacharoeniae sp. nov. and Candida spenceri sp. nov., two novel galactose-containing ascomycetous anamorphic yeast species isolated in Thailand

Fifteen strains of anamorphic yeasts isolated from various natural substrates collected in various places in Thailand were found to represent two novel species of anamorphic yeast genus Candida based on the sequence analysis of the D1/D2 domain of the large subunit rRNA genes, chemotaxonomic and conventional properties used for the classification of yeasts. These strains are located in the clade including Candida etchellsii and Candida magnoliae. Fourteen strains represented by ST-490(T) (BCC 15176(T)=NBRC 106439(T)= CBS 11674(T)) are closely related to Candida sorbosivorans in the D1/D2 sequences but 11 nucleotides (2.4%) were substituted. The remaining strain, ST-594(T) (=BCC 15278(T)=NBRC 106446(T)=CBS 11673(T)) showed a close relationship to Candida geochares but 21 nucleotides (4.7%) were substituted. Apparently, these strains represent two novel Candida species of the Starmerella clade. The two species are described as Candida potacharoeniae sp. nov. and Candida spenceri sp. nov. in the present paper. Like the most species of this clade, the two species contain galactose in the cells in addition to glucose and mannose and have high mol% G + C of 54.4-55.9 and 54.9, respectively.     

Candida dajiaensis sp. nov., Candida yuanshanicus sp. nov., Candida jianshihensis sp. nov., and Candida sanyiensis sp. nov., four anamorphic, ascomycetous yeast species isolated from soil in Taiwan

Nine anamorphic, ascomycetous yeast strains belonging to the Pichia anomala clade were recovered from forest soil in 2006 in Taiwan. The nine yeast strains represent four novel yeast species based on the sequences of their D1/D2 domain of the large subunit (LSU) rRNA gene and their physiological characteristics. The scientific names of Candida dajiaensis sp. nov., Candida yuanshanicus sp. nov., Candida jianshihensis sp. nov., and Candida sanyiensis sp. nov. are proposed for these novel yeast species. The type strains are C. dajiaensis SM11S03(T) (=CBS 10590(T)=BCRC 23099(T)), C. yuanshanicus SY3S02(T) (=CBS 10589(T)=BCRC 23100(T)), C. jianshihensis SM8S04(T) (=CBS 10591(T)=BCRC 23096(T)), and C. sanyiensis SA1S06(T) (=CBS 10592(T)=BCRC 23094(T)). Sequence analysis of the D1/D2 of the LSU rRNA gene revealed that the three species, C. dajiaensis, C. yuanshanicus and Pichia onychis, shared a separate branch in the phylogenetic tree, C. jianshihensis is phylogenetically related to Candida ulmi and Pichia alni, and the phylogenetically closest relative of C. sanyiensis is Pichia populi.     

Torulaspora quercuum sp. nov. and Candida pseudohumilis sp. nov., novel yeasts from human and forest habitats

Strains XZ-46A, XZ-105, XZ-129 and XZ-281^T isolated from the oral cavities of healthy Tibetan volunteers were revealed to represent two novel ascomycetous yeast species by molecular taxonomic characterizations. Strain XZ-281^T was most closely related to Candida humilis , but differed from the type strain of the species by eight (1.2%) substitutions in the 26S rRNA gene D1/D2 domain and by >100 (>20%) mismatches in the internal transcribed spacer (ITS) region. Strains XZ-46A, XZ-105 and XZ-129 had identical or similar D1/D2 and ITS sequences with each other and with strain 17YF^T isolated from a leaf of an oak tree ( Quercus sp.). The closest relative of this group was Torulaspora microellipsoides . They differed from the type strain of the species by five (0.9%) substitutions in the D1/D2 domain and >70 (>15%) mismatches in the ITS region. A sexual state was observed in strain 17YF^T, but not in the other four oral strains. An anamorphic name Candida pseudohumilis sp. nov. is proposed for strain XZ-281^T (=AS 2.3956^T=CBS 11404^T) and a teleomorphic name Torulaspora quercuum sp. nov. is proposed for strain 17YF^T (=AS 2.3768^T=CBS 11403^T) and the other three oral strains.     

Three anamorphic yeast species Candida sanitii sp. nov., Candida sekii sp. nov. and Candida suwanaritii, three novel yeasts in the Saturnispora clade isolated in Thailand

Nine strains of three novel anamorphic yeast species were obtained from samples collected in Thailand including six strains (RV96, RV152, R14, RS9, RS58 and EA1) obtained from estuarine waters collected from two mangrove forests, one strain (ST84) from insect frass and two strains (SR16 and UB13) from forest soils. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analysis of the D1/D2 domain of the large subunit rRNA gene, the nine strains were found to represent three novel Candida species in the Saturnispora clade. Five strains (RV96, RV152, R14, RS9 and RS58) were assigned as a single novel species, which was named Candida sanitii sp. nov. The type strain is RV152^T (BCC 25967^T=NBRC 103864^T=CBS 10864^T). Strain EA1 was named as Candida suwanaritii sp. nov. The type strain is EA1^T (BCC 29900^T=NBRC 104877^T=CBS 11021^T). Three strains (ST84, SR16 and UB13) represented another novel species, for which Candida sekii sp. nov. is proposed. The type strain is ST84^T (BCC 8320^T=NBRC 105671^T=CBS 10931^T).     

Four novel species of the anamorphic yeast genus Candida found in Thailand and Taiwan

Four strains of yeasts isolated in Thailand and Taiwan were found to represent four distinct novel species of the ascomycetous anamorphic yeast genus Candida. These strains are located in the Clavispora-Metschnikowia clade in a phylogenetic tree based on the D1/D2 domain sequences of the large subunit rRNA genes. Together with Candida picinguabensis and Candida saopaulonensis, the four novel species constitute a well-separated subclade from other species of the Clavispora-Metschnikowia clade. Three species from Thailand are described as Candida bambusicola sp. nov. (type strain, ST-50(T) = BCC 7750(T) = NBRC 106734(T) = CBS 11723(T)), Candida nongkhaiensis sp. nov. (type strain, ST-95(T) = BCC 8331(T) = NBRC 105874(T) =CBS 11724(T)) and Candida succicola sp. nov. (type strain, ST-631(T) = BCC 15314(T) = NBRC 106736(T) = CBS 11726(T)), respectively, and the species from Taiwan is described as Candida touchengensis sp. nov. (type strain, SY4S03(T) = NBRC 102647(T) = BCRC 23097(T) = CBS 10585(T)).     

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.     

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.     

Cryptococcus foliicola sp. nov. and Cryptococcus taibaiensis sp. nov., novel basidiomycetous yeast species from plant leaves

A molecular taxonomic investigation performed on basidiomycetous yeast strains isolated from plant leaves collected in two areas of China revealed two novel species, Cryptococcus foliicola sp. nov. (type strain HS 23.3(T) = AS 2.2471(T) = CBS 9920(T)) and Cryptococcus taibaiensis sp. nov. (type strain ST 7.9(T) = AS 2.2444(T) = CBS 9919(T)), among the non ballistoconidium-forming strains producing cream-colored colonies. These new species differed markedly from closely related species in the internal transcribed spacer (ITS) and 26S rRNA D1/D2 region sequences. They clustered in a strongly supported clade represented by Cryptococcus victoriae in the Tremellales group in the phylogenetic trees drawn from ITS and D1/D2 sequences.     

Candida nonsorbophila sp. nov., a new ascomycetous yeast species isolated in Thailand

Four yeast strains, RS42, SSK10, ST-520 and ST-521, isolated from water in a mangrove forest, bark of a tree and fruit of Ficus sp., respectively, were found to represent a hitherto undescribed anamorphic species. The four strains are related to Candida sinolaborantium in the D1/D2 domain of the large subunit rRNA gene, but differed by eight nucleotide substitutions and two indels, and for this reason are regarded as members of a separate species. Because ascospore formation was not detected, it is described as a new species of Candida, Candida nonsorbophila sp. nov. The type strain is RS42^T (BCC 25963^T=NBRC 103860^T=CBS 10862^T). This species is distinguished from C. sinolaborantium by the inability to assimilate l -sorbose, l -rhamnose and galactitol, and a higher maximum growth temperature.