Serological relationships among some Pichia species.

Antigenic analyses of five species of the genus Pichia were carried out for taxonomic study by the slide agglutination method using monospecific and absorbed antisera and the agglutinin absorption technique. Comparative studies were also performed with a few strains of each of the same species and their classifications are discussed with respect to the antigenic structures and the patterns of proton magnetic resonance (PMR) spectra of their cell wall polysaccharides. ichia delftensis and Pichia zaruensis possessed thermostable antigens 1,2,5 and 11, and the former had also thermoabile antigen m. Both species were closely related to Candida krusei. Pichia toletana possessed thermostable antigens 1,2,5,11,17 and 49. Pichia bovis contained thermostable antigens 1,2,14,15,16,20 and 21, and it was related to most species of the genus Hansenula, although assimilation of potassium nitrate was negative. Finally, Pichia etchellsii possessed thermostable antigens 1,2,3,4,9 and 14, and was closely related to Pichia vini. Patterns of PMR spectra of mannans of these species also supported their serological relationships. Therfore, P. delftensis, P. zaruensis and P. etchellsii are considered to be the synonyms of Pichia fluxuum, Pichia dispora and P. vini respectively, although P. toletanan and P. bovis are independent species.     

Endomycopsis vini andPichia etchellsii,spp.n.

Two new yeast species are described:Endomycopsis vini has been isolated from grapes,Pichia etchellsii from fermenting cucumber brines.     

Activité Enzymatique Des Ascomycetes: Pichia Vini Et Pichia Vini Var. Melibiosi

Résumé Pichia vini etPichia vini var.melibiosi sont comparées en tenant compte des systèmes enzymatiques intracellulaires et non plus seulement des caractères d'assimilation du cellobiose et du mélibiose. La présence de système enzymatique susceptible d'hydrolyser les glucosides chezP. vini var.melibiosi et les galactosides chezP. vini sont des arguments valables pour synonymiser les 2 variétés.

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Pichia vini andPichia vini var.melibiosi are compared in respect to their intracellular enzymatic systems concerning cellobiose and melibiose. Both species possess intracellular glucosidase and galactosidase with the same characteristics. It seems that the separation between the 2 varieties is not valuable after our results.

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Étude particulière de l' galactosidase et de la-glucosidase, conséquences taxonomiques.     

Systematics of the generaDebaryomyces andMetschnikowia: Proton magnetic resonance spectra of their mannans as an aid in classification

The proton magnetic resonance spectra of the mannans of a number ofDebaryomyces andMetschnikowia species (Endomycetales) were determined. The spectra of all of the mannans had several similar characteristics, regardless of the species from which they originated. Pichia vini, a species originally classified asDebaryomyces vini, formed a mannan with a spectrum almost identical with those ofMetschnikowia (Candida) reukaufii andPichia haplophila. Debaryomyces vanrijii, originally placed in the genusPichia, formed a mannan with a spectrum identical with those ofPichia robertsii andCandida (Pichia) guilliermondii mannans.The authors wish to thank Mr. M. Mazurek for the determination of the p.m.r. spectra, and Mr. N. R. Gardner and Mr. R. J. Magus for valuable technical assistance.     

Relevance of the ecology ofCitrus yeasts to the diet ofDrosophila

A study of the yeast flora of necrotic oranges and associatedDrosophila yielded a total of 221 isolates composed ofKloeckera apiculata (75),Pichia fermentans (75),Pichia kluyveri (50),Torulopsis stellata (17),Hanseniaspora uvarum (2),P. membranaefaciens (1), andCandida vini (1). The yeast species of all samples of oranges and adultDrosophila were very similar; however, the speciesof Drosophila contained a higher proportion ofP. fermentans and a lower proportion ofK. apiculata than was found in the rotting oranges.P. fermentans was subsequently found more frequently on the surface of the necrotic tissue, where the flies feed, than was found internally. SinceP. fermentans characteristically produces a pellicle and pseudomycelium andK. apiculata does not, it is concluded that the growth characteristics of the yeasts are an important factor determining adultDrosophila diets.     

A proposal for amendment of the diagnosis of the genusPichia hansen

Summary An amended diagnosis has been given for the genusPichia Hansen to allow inclusion of species characterized by a lack of pellicle formation, by the absence or a strongly reduced pseudomycelium or by a combination of both properties. The following species fit the amended diagnosis ofPichia: P haplophila Shifrine et Phaff,P. carsonii Phaff et Knapp,P. quercibus Phaff et Knapp andP. xylosa Phaff, Miller et Shifrine. Furthermore, it has been proposed to transferSaccharomyces pastori Guilliermond,Saccharomyces pini Holst andDebaryomyces vini Zimmermann to the amended genusPichia, where they fit well rather than occupying and exceptional position in their present genera.     

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.     

DNA relatedness among saturn-spored yeasts assigned to the generaWilliopsis andPichia

Saturn-spored species assigned to the generaWilliopsis andPichia were compared from extent of nuclear DNA complementarity. Of thePichia spp., four were recognized as distinct taxa:P. dispora, P. saitoi, P. zaruensis andPichia sp. nov. AmongWilliopsis spp., the following were accepted:W. californica, W. mucosa comb. nov.,W. pratensis, W. saturnus var.saturnus, W. saturnus var.mrakii comb. nov.,W. saturnus var.sargentensis comb. nov.,W. saturnus var.subsufficiens comb. nov. andWilliopsis sp. nov. The newPichia andWilliopsis species are described elsewhere. Moderate (36–68%) DNA relatedness was detected between the formerPichia sargentensis and varieties ofW. saturnus again demonstrating that nitrate assimilation is not a reliable criterion for separating yeast species.     

Phylogenetic relationships among species ofWilliopsis andSaturnospora gen. nov. as determined from partial rRNA sequences

Phylogenetic relationships among those yeast species that form saturn-shaped ascospores and which are assigned to the generaWilliopsis andPichia were estimated from their extent of nucleotide sequence divergence in three regions of ribosomal RNA. ThePichia species (P. dispora, P. saitoi, P. zaruensis andP. sp. nov.) are a closely clustered group only distantly related toWilliopsis, and it is proposed that they be reassigned toSaturnospora gen. nov. The extent of divergence amongWilliopsis species (W. californica, W. mucosa, W. pratensis, W. saturnus andW. sp. nov.) is greater than that previously observed within other ascomycetous yeast genera.     

Polymorphisms of 20 regulatory proteins between Mycobacterium tuberculosis and Mycobacterium bovis

Mycobacterium tuberculosis and Mycobacterium bovis are responsible for tuberculosis in humans and animals, respectively. Both species are closely related and belong to the Mycobacterium tuberculosis complex (MTC). M. tuberculosis is the most ancient species from which M. bovis and other members of the MTC evolved. The genome of M. bovis is over >99.95% identical to that of M. tuberculosis but with seven deletions ranging in size from 1 to 12.7 kb. In addition, 1200 single nucleotide mutations in coding regions distinguish M. bovis from M. tuberculosis. In the present study, we assessed 75 M. tuberculosis genomes and 23 M. bovis genomes to identify non‐synonymous mutations in 202 coding sequences of regulatory genes between both species. We identified species‐specific variants in 20 regulatory proteins and confirmed differential expression of hypoxia‐related genes between M. bovis and M. tuberculosis.     

Identification of species in the genus Pichia by restriction of the internal transcribed spacers (ITS1 and ITS2) and the 5.8S ribosomal DNA gene

In this study, the variability within the ribosomal DNA region spanning the internal transcribed spacers ITS1 and ITS2 and the 5.8S gene (5.8S-ITS rDNA) was used to differentiate species in the genus Pichia. The 5.8S-ITS rDNA region was PCR-amplified and the PCR product digested with the enzymes CfoI, HinfI, and HaeIII. The variability in the size of the amplified product and in the restriction patterns enabled differentiation between species in the genus Pichia, and between Pichia species and yeast species from other genera in the Yeast-id database (). Moreover, the restriction fragment length polymorphism (RFLP) patterns of the 5.8S-ITS enabled misidentified strains to be detected and revealed genetic heterogeneity between strains within the Pichia membranifaciens and Pichia nakazawae species. Ultimately, the RFLP patterns of the 5.8S-ITS rDNA failed to differentiate between some Pichia and Candida species that could be distinguished on the basis of the sequence of the 5.8S-ITS rRNA region or the sequence of the D1/D2 domain of the 26S rDNA gene.     

Immunological relationship of extra-cellular polysaccharide antigens produced by different mould species

Moulds are able to produce extracellular polysaccharide antigens which are heat-stable and almost genus specific. Of 44 different strains of Penicillium 41 (93%) and all 12 strains of Aspergillus tested produced detectable quantities of an immunologically related antigen. Additionally 10 of these 56 strains produced an antigen immunologically related to the antigen produced by the genera Mucor and Fusarium. Immunologically different, but genus-specific antigens were produced by each of the species belonging to the genus Geotrichum, Fusarium, Cladosporium, Mucor and Rhizopus. The antigens produced by Mucor and Rhizopus, however, were immunologically related.     

Phylogeny of the Malus (Apple Tree) Species,Inferred from the Morphological Traits and Molecular DNA Analysis

Some debated issues of the genus Malus (apple) taxonomy were examined using a variety of species from the collection of the Maikop Experimental Station, Vavilon Research Institute of Plant Industry (Krasnodar krai). Phylogenetic relationships among these species were studied using traditional analysis of morphological traits, RAPD, and complete sequencing of the 5"- internal transcribed spacer (ITS1), 5.8S rRNA, 3"- internal transcribed spacer (ITS2) (constituting a cluster of the rRNA genes), and the terminal fragment of the matK gene encoding chloroplast maturase. The results showed that the Sorbomalussection was polyphyletic; the American apple M. fusca was closely related to the species contributing to the East Asian center of the genus origin, and the American speciesM. angustifolia, M. coronaria, and M. ioensis were closely related to the M. trilobata relict species, whose assignment to the genus Malus is debated by some authors. Molecular analysis of the species relationships showed that the Middle Asian apple M. sieversii is the species from which apple domestication started.     

The Phylogeny of Species of the Genus Saccharomycopsis Schiönning (Saccharomycetaceae) Based on the Partial Sequences of 18S and 26S Ribosomal RNAs

Eight strains of Saccharomycopsis species were examined for their partial base sequences of 18S and 26S rRNAs. The base sequences on the fingerprint segment showed three kinds of ACUAU, UCUAU, and AUAU. In the partial base sequences (positions 1451–1618, 168 bases) of 18S rRNA, all the strains of Saccharomycopsis species examined had 1–0 base difference except for the strains of Saccharomycopsis fibuligera (base differences, 5–4). In the partial base sequences on the positions 1611–1835 region (225 bases) of 26S rRNA, however, S’copsis vini had 15–11 base differences. The other species had 7–2 base differences. In the partial base sequences on the positions 493–622 region (130 bases) of 26S rRNA, the calculated percent similarities were 62–77. Discussion was made phylogenetically and taxonomically, especially on the separation of S’copsis fibuligera (≡ Endomyces fibuliger) from the genus Saccharomycopsis.     

Taxonomic genetics of <Emphasis Type="Italic">Zygowilliopsis</Emphasis> yeasts

Genetic hybridization analysis was conducted with 16 natural Zygowilliopsis strains isolated in different geographical regions and maintained in collections under species names Z. californica, Hansenula dimennae, and Pichia populi. Genetic relatedness was determined on the basis of mating, viability of hybrid progeny, and meiotic recombination of markers. Four new biological species are recognized in the former monotypic genus Zygowilliopsis. Species Z. californica and Zygowiliopsis sp. 3 probably include divergent geographical populations. It is necessary to reconsider the species composition of the genus Zygowiliopsis and generic assignment of P. populi yeasts. Genetic and molecular identifications of the Zygowiliopsis species are in perfect agreement.     

Some remarks on the taxonomic status of Paraschizopera Wells, 1981 (Copepods: Harpacticoida)

The monotypic genus Paraschizopera Wells, 1981 (ex Diosaccidae) is transferred to the Tetragonicipitidae on the basis of segmentation of antennary exopod and P2-P4 endopods, setation of P1 and overall similarity in mouthpart structure. Paraschizopera is the most primitive genus of the family and closely related to Diagoniceps Willey, 1930 which is redefined to encompass only the laevis-group. The menaiensis-group is allocated to Paraschizopera which includes now P. beckeri Wells (type-species), P. menaiensis (Geddes) and P. trifida (Yeatman). The new name D. brevicauda is proposed for Diagoniceps sp. sensu Bodin (1979). Keys are provided to the species of Paraschizopera and Diagoniceps, and to the genera of the Tetragonicipitidae.     

Bioconversion of Ferulic Acid to 4-Vinylguaiacol and 4-Ethylguaiacol and of 4-Vinylguaiacol to 4-Ethylguaiacol by Halotolerant Yeasts Belonging to the Genus Candida

In order to examine the genesis of the characteristic flavors of soy sauce and miso, seven novel halotolerant yeast strains of two types, which showed convertibility of ferulic acid (FA) to 4-vinylguaiacol (4-VG) and to 4-ethylguaiacol (4-EG), were isolated from miso-koji and miso pastes. Two of these strains were identified as Candida guilliermondii (anamorph of Pichia guilliermondii), and Candida fermentati (anamorph of Pichia caribbica), based on sequence analyses of a partial 26S ribosomal RNA gene and the region of internal transcribed spacers 1 and 2, and the 5.8S ribosomal RNA gene. Moreover, we also found three Candida etchellsii strains which showed convertibility of FA to 4-VG, but not to 4-EG, and two atypical strains of Candida versatilis which showed no convertibility of FA to 4-VG, but did show convertibility of 4-VG to 4-EG from soy sauce mashes. The bioconversion pathway from FA to 4-EG via 4-VG in halotolerant yeasts and bacteria is discussed.     

Protognathia n. gen. bathypelagica (Schultz, 1977) rediscovered in the Weddell Sea: A missing link between the Gnathiidae and the Cirolanidae (Crustacea,Isopoda)

Summary A new genus (Protognathia) and family (Protognathiidae) are described for Cirolana bathypelagica Schultz, 1977. The morphology of this unique species proves that the Gnathiidae are closely related to the Cirolanidae. The characters of P. bathypelagica are intermediate between the carnivorous cirolanids and the highly specialized gnathiid fish parasites.Abbreviations used in text and figures A 1,2 antenna 1,2 - Md mandible - Mx1 maxilla 1 - Mxp maxilliped - P 1-6 pereopods 1-6 - Plp 1-5 pleopods 1-5 - Tel telson - Urp uropod