Insights into the ecology of Schizosaccharomyces species in natural and artificial habitats

The fission yeast genus Schizosaccharomyces contains important model organisms for biological research. In particular, S. pombe is a widely used model eukaryote. So far little is known about the natural and artificial habitats of species in this genus. Finding out where S. pombe and other fission yeast species occur and how they live in their habitats can promote better understanding of their biology. Here we investigate in which substrates S. pombe, S. octosporus, S. osmophilus and S. japonicus are present. To this end about 2100 samples consisting of soil, tree sap fluxes, fresh fruit, dried fruit, honey, cacao beans, molasses and other substrates were analyzed. Effective isolation methods that allow efficient isolation of the above mentioned species were developed. Based on the frequency of isolating different fission yeast species in various substrates and on extensive literature survey, conclusions are drawn on their ecology. The results suggest that the primary habitat of S. pombe and S. octosporus is honeybee honey. Both species were also frequently detected on certain dried fruit like raisins, mango or pineapple to which they could be brought by the honey bees during ripening or during drying. While S. pombe was regularly isolated from grape mash and from fermented raw cacao beans S. octosporus was never isolated from fresh fruit. The main habitat of S. osmophilus seems to be solitary bee beebread. It was rarely isolated from raisins. S. japonicus was mainly found in forest substrates although it occurs on fruit and in fruit fermentations, too.

     

Ferroplasma cupricumulans sp. nov., a novel moderately thermophilic, acidophilic archaeon isolated from an industrial-scale chalcocite bioleach heap

A new species of Archaea was isolated from an industrial mineral sulphide bioleach heap. Strain BH2, a non-motile pleomorphic coccus, was capable of chemomixotrophic growth on ferrous sulphate and yeast extract. Growth was not supported in the absence of yeast extract. Phylogenetic analysis based on the 16S rRNA gene showed that strain BH2 was most closely related to the species Ferroplasma acidiphilum; however, it showed only 95% sequence similarity with this species. Strain BH2 had a temperature optimum of 53.6°C and a temperature range for growth between 22 and 63°C. Thus, it is the first moderately thermophilic member of the genus Ferroplasma. The optimum pH for the growth of the strain occurred between pH 1.0 and 1.2 and the lowest pH at which growth was observed was 0.4. Based on 16S rRNA gene sequence analysis and other physiological characteristics, strain BH2 constitutes a new species within the genus Ferroplasma. The name Ferroplasma cupricumulans is proposed for the new species and strain BH2 (DSM 16651) is proposed as the type strain.     

Trichosporon siamense sp. nov. isolated from insect frass in Thailand

A strain of yeast isolated from insect frass collected in Thailand was found to represent a hitherto undescribed species of a basidiomycetous anamorphic genus Trichosporon. It is described as Trichosporon siamense. In the phylogenetic tree based on the D1/D2 region sequences of 26S rDNA, this yeast constitutes a cluster with several Q-9 having species of Trichosporon including T. otae and T. brassicae but is clearly differentiated from these species by 1.8% or more base substitutions. In the internal transcribed spacer region (ITS1 and ITS2), this species differs from T. scarabaeorum, the nearest species, by 6.5% base substitution.     

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.     

<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.     

Cryptococcus haglerorum,sp. nov., an anamorphic basidiomycetous yeast isolated from nests of the leaf-cutting ant Atta sexdens

A yeast strain (CBS 8902) was isolated from the nest of a leaf-cutting ant and was shown to be related to Cryptococcus humicola. Sequencing of the D1/D2 region of the 26S ribosomal DNA and physiological characterization revealed a separate taxonomic position. A novel species named Cryptococcus haglerorum is proposed to accommodate strain CBS 8902 that assimilates n-hexadecane and several benzene compounds. Physiological characteristics distinguishing the novel species from some other members of the C. humicola complex are presented. The phylogenetic relationship of these strains to species of the genus Trichosporon Behrend is discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

DNA SEQUENCE DATA DEMONSTRATE THE POLYPHYLY OF THE GENUS CYSTOSEIRA AND OTHER SARGASSACEAE GENERA (PHAEOPHYCEAE)1

Phylogenetic relationships in the Sargassaceae were explored using three DNA markers, and the monophyly of its genera was challenged. Nineteen out of 24 currently recognized genera were sampled, representing 63 species. The variable mt23S‐tRNA Val intergenic spacer could only be aligned within genera and could not be used to infer intergeneric relationships. The partial mt23S was also useful to delineate genera and was alignable at the family level but provided few informative characters. Analysis of mt23S DNA sequences together with chloroplast‐encoded psbA sequences resulted in a better resolved phylogeny. Hormophysa was the first genus to branch off within the Sargassaceae, followed by Myriodesma; then the three genera Caulocystis, Carpoglossum, and Scaberia in unresolved order; and then Acrocarpia. The other taxa studied here were divided over three major clades, but there was no branch support for the monophyly of two of these. The genera Bifurcaria, Cystoseira, Halidrys, and Sargassum appeared polyphyletic. The following taxonomic changes are proposed: a new genus Brassicophycus for Bifurcaria brassicaeformis (Kützing) E. S. Barton; reinstatement of the genus Sargassopsis for Sargassum decurrens (R. Brown ex Turner) C. Agardh; reinstatement of the genus Sirophysalis for Indo‐Pacific Cystoseira trinodis (Forsskål) C. Agardh; reinstatement of the genus Polycladia for the western Indian Ocean species Cystoseira indica (Thivy et Doshi) Mairh, Cystoseira myrica (S. G. Gmelin) C. Agardh, and Acystis heinii Schiffner; and reinstatement of the genus Stephanocystis for the North Pacific Cystoseira species and Halidrys dioica N. L. Gardner. The European Cystoseira species should be split into three genera, but no name changes are proposed yet, because diagnostic characters were found only for the clade including the type species. Some evolutionary trends could be discerned from the mt23S + psbA phylogeny.     

<Emphasis Type="Italic">Rhodotorula taiwanensis</Emphasis> sp. nov., a novel yeast species from a plant in Taiwan

A novel anamorphic yeast strain, A1-01^T, belonging to the genus Rhodotorula was isolated from a plant in Taiwan and analysed morphologically, physiologically and phylogenetically. Neither ballistoconidia nor sexual reproduction was observed. Sequence analysis of the 26S rRNA gene and the ITS region indicate that Rhodosporidium sphaerocarpum is the most closely related species, with 14 and 24 nucleotide substitutions, respectively. The novel species differed physiologically from R. sphaerocarpum in its ability to assimilate ethylamine and cadaverine, its inability to assimilate ethanol and nitrite. From these comparative analyses, the following novel yeast species is proposed: Rhodotorula taiwanensis sp. nov. with the type strain of A1-01^T (BCRC 23118^T = CBS 11729^T).     

Citeromyces cibodasensis sp. nov., a novel yeast species isolated from leaf litter in Indonesia

A novel yeast species was isolated from leaf litter of Macropanax dispermus obtained from the Cibodas Botanical Garden, West Java, Indonesia. The two strains of the species displayed typical characteristics of the genus Citeromyces. Phylogenetic analysis based on the gene sequences of the D1/D2 domains of large subunit (LSU) rDNA, internal transcribed spacer (ITS) including 5.8S rDNA, mitochondrial small-subunit rRNA gene (MtSm), and translation elongation factor-1α (EF-1α) showed that the novel strains were clearly separated from the other four existing species of the genus Citeromyces. Therefore, the two strains were proposed to represent a novel species within the genus Citeromyces, for which the name Citeromyces cibodasensis is proposed; the type strain is NBRC 110244^T (= CBS 14272^T?=?InaCCY703^T?=?AK 01).     

<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.     

Extreme degree of chromosome number variability in species of the spider genus Scytodes (Araneae, Haplogynae, Scytodidae)

Genus Scytodes includes most species of the spider family Scytodidae. Until now, 187 species of the genus have been described. In spite of this great diversity, only three Scytodes species were karyotyped so far. The present paper provides for the first time karyotype analysis of two synanthropic species, Scytodes fusca and Scytodes itapevi. Furthermore, new data on karyotype of Scytodes globula are also provided using conventional and differential cytogenetical procedures. The diploid number in the genus Scytodes varied considerably, namely from 2n = 13 to 2n = 31. The diploid number found in S. globula (2n♂ = 13) is the lowest in haplogyne spiders with monocentric chromosomes. Except S. globula, this number has been found only in one haplogyne spider with monocentric chromosomes, namely Ochyrocera sp. (Ochyroceratidae). On the contrary, the diploid number of S. fusca (2n♂ = 31) is one of the highest diploid numbers recorded in haplogyne spiders. The degree of intrageneric variation found in the genus Scytodes is the highest recorded in araneomorph spiders with monocentric chromosomes so far. Some karyotype characteristics (diploid number, chromosome morphology, total chromosome length, and distribution of constitutive heterochromatin) allowed us to postulate a close relationship between S. globula and S. itapevi. According to the karyotype data, S. fusca is not closely related to these two species. This conclusion corroborates a recent taxonomic work that grouped S. globula, S. itapevi, and other four Scytodes species in the ‘globula group’.     

Taxonomic notes on the genus Strongylopsalis Burr (Dermaptera: Labiidae)

The male and female of a new species of Strongylopsalis are described from Bolivia. Carcinophora boliviana Bormans is redescribed, and its position in the genus Strongylopsalis is confirmed; a new name is proposed for S.boliviana Brindle. A key is given to the ten species now contained in Strongylopsalis, and notes on the distribution of the genus and its possible relationship to Marava are included.     

TAXONOMY AND MOLECULAR PHYLOGENY OF THE RED ALGAL GENUS LENORMANDIA (RHODOMELACEAE,CERAMIALES)1

The genus Lenormandia Sonder is currently composed of nine species from Australia and New Zealand. Some of these are well known, but others are rare and ill defined. Material of all nine species has been examined and found to fall into three discrete morphological groups forming highly supported clades on analysis of 18S rDNA sequences. The first group contains four Australian‐endemic species and includes the type species L. spectabilis Sonder. Plants have a cleft apex that is not inrolled, a distinctive rhombic surface areolation pattern caused by a one‐ to two‐layered medulla of interlocking cells, lack pseudopericentral cells, and produce their reproductive structures on the blade surfaces. The type species of the genus Lenormandiopsis, L. latifolia (Harvey et Greville) Papenfuss, was found to belong to this group and is thus returned to Lenormandia where it was originally placed. Species falling into the other two groups are removed to new genera that are being described separately. One extremely rare species of Lenormandia from southwestern Australia is transferred to the delesseriacean genus Phitymophora.     

A revision of the phoretic deutonymphs (hypopi) of the genus Sennertia Oudemans, 1905 (Acari,Astigmata, Chaetodactylidae)

Summary The genus Sennertia Oudemans, 1905 (Acari, Chaetodactylidae) is revised. Up to now, 49 species have been described in this genus, almost all from their hypopial stage. Adults are known only for four species. The adults live in the nests of bees, mainly Xylocopidae, and their heteromorphic deutonymphs ( = hypopi) are phoretic on the bees. The parasitic role of these mites is not known but they probably feed on the bee larvae as do the members of the allied genus Chaetodactylus wich are parasitic in the nests of Megachilidae. The holotypes or lectotypes of 35 species have been examined and most of them are redescribed and redepicted. Four species have been placed in synonymy: S. moandensis Fain, 1971 with S. morstatti Vitzthum, 1914; S. xylocopae (Donnadieu, 1868) with S. cerambycina (Scopoli, 1763); S. sumatrensis Oudemans, 1924 with S. horrida (Vitzthum, 1912); S. donaldi Turk, 1948 with S. argentina Vitzthum, 1941. The genus Sennertia is redefined from the hypopial stage and four new subgenera (Afrosennertia, Asiosennertia, Amsennertia and Spinosennertia) and two new species S. (Asiosennertia) vitzthumi and S. (Asiosennertia delfinadoae) are described. A key to the species is given. ac]19810331     

The genus Saitobryum (Pottiaceae) revisited

The genus Saitobryum R.H.Zander comprises two species: S. lorentzii (Müll.Hal.) Ochyra distributed in Mexico and the Central Andes and Saitobryum pascoense M.J.Cano & J.A.Jiménez from the Central Andes of Peru, described here as new. The new species is distinguished from S. lorentzii by its upper and middle laminal cells papillose throughout, border of 2–3 rows of thick-walled and smooth cells, lamina usually with bistratose patches, and occasionally bistratose margins. The diagnostic characters of Saitobryum are re-evaluated and a key to the species of this genus is provided. Both species are described and illustrated. New localities for S. lorentzii and a map showing the complete distribution of this genus are given.     

Unexpected distribution patterns of Carduiceps feather lice (Phthiraptera: Ischnocera: Philopteridae) on sandpipers (Aves: Charadriiformes: Scolopacidae)

The louse genus Carduiceps Clay & Meinertzhagen, 1939 is widely distributed on sandpipers and stints (Calidrinae). The current taxonomy includes three species on the Calidrinae (Carduiceps meinertzhageni, Carduiceps scalaris, Carduiceps zonarius) and four species on noncalidrine hosts. We estimated a phylogeny of four of the seven species of Carduiceps (the three mentioned above and Carduiceps fulvofasciatus) from 13 of the 29 hosts based on three mitochondrial loci, and evaluated the relative importance of flyway differentiation (same host species has different lice along different flyways) and flyway homogenization (different host species have the same lice along the same flyway). We found no evidence for either process. Instead, the present, morphology‐based, taxonomy of the genus corresponds exactly to the gene‐based phylogeny, with all four included species monophyletic. Carduiceps zonarius is found both to inhabit a wider range of hosts than wing lice of the genus Lunaceps occurring on the same group of birds, and to occur on Calidris sandpipers of all sizes, both of which are unexpected for a body louse. The previously proposed family Esthiopteridae is found to be monophyletic with good support. The concatenated dataset suggests that the pigeon louse genus Columbicola may be closely related to the auk and diver louse genus Craspedonirmus. These two genera share some morphological characters with Carduiceps, but no support was obtained for grouping these three genera together. Based on mitochondrial data alone, the relationships among genera within this proposed family cannot be properly assessed, but some previously suggested relationships within this proposed family are confirmed.     

A revision of the genus Sclerosperma (Arecaceae)

Summary  A taxonomic revision of the palm genus Sclerosperma (Arecaceae) is presented. Three species are recognised: S. mannii H. Wendl., which is relatively widespread from Liberia to the Democratic Republic of Congo; S. walkeri A. Chev., which is apparently confined to the interior of Gabon and a band along the Congo River; and S. profiziana, a new species previously considered conspecific to S. mannii that is found in southwest Ghana, Congo, the Democratic Republic of Congo and Angola. The taxonomic history, morphology, distribution and conservation status of the genus and each species are discussed.     

Yeast water channels: an overview of orthodox aquaporins

In yeast, the presence of orthodox aquaporins has been first recognized in Saccharomyces cerevisiae, in which two genes (AQY1 and AQY2) were shown to be related to mammal and plant water channels. The present review summarizes the putative orthodox aquaporin protein sequences found in available genomes of yeast and filamentous fungi. Among the 28 yeast genomes sequenced, most species present only one orthodox aquaporin, and no aquaporins were found in eight yeast species. Alignment of amino acid sequences reveals a very diverse group. Similarity values vary from 99% among species within the Saccharomyces genus to 34% between ScAqy1 and the aquaporin from Debaryomyces hansenii. All of the fungal aquaporins possess the known characteristic sequences, and residues involved in the water channel pore are highly conserved. Advances in the establishment of the structure are reviewed in relation to the mechanisms of selectivity, conductance and gating. In particular, the involvement of the protein cytosolic N‐terminus as a channel blocker preventing water flow is addressed. Methodologies used in the evaluation of aquaporin activity frequently involve the measurement of fast volume changes. Particular attention is paid to data analysis to obtain accurate membrane water permeability parameters. Although the presence of aquaporins clearly enhances membrane water permeability, the relevance of these ubiquitous water channels in yeast performance remains obscure.