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At least 649 records · Page 36Linked to original sources
PubMed1984

Trichosporon adeninovorans sp. nov., a yeast species utilizing adenine, xanthine, uric acid, putrescine and primary n-alkylamines as the sole source of carbon, nitrogen and energy.

A new yeast species, Trichosporon adeninovorans, was isolated from soil by the enrichment culture method. Apart from adenine, the strain utilized uric acid, guanine, xanthine, hypoxanthine, 6,8-dihydroxypurine, putrescine, propylamine, butylamine, pentylamine, hexylamine and octylamine as sole source of carbon, nitrogen and energy. The structure of the cell wall of Tr. adeninovorans was ascomycetous. On the subcellular level growth on adenine or uric acid was accompanied with the development of microbodies in the cell. These cell organelles probably were the site of urate oxidase, an enzyme that, after growth on purine substrates, together with allantoinase was present at high activities. Low activities of adenine amidohydrolase and xanthine dehydrogenase were also demonstrated.

Adenine↗
PubMed1983

Distribution and strain-dependent formation of volatile metabolites in the genus Ceratocystis.

The accumulation of volatile metabolites in cultures of 34 strains comprising ten species of the genus Ceratocystis (Ascomycetes) has been investigated under defined culture conditions. The identified compounds include short-chain alcohols and esters, lower terpenes, terpenoids, and 2-phenylethyl acetate. Certain species can be recognized by a number of common volatiles traced in all strains, although the quantities of these constituents may vary enormously (up to a factor 1:1000) within one species. The formation of some metabolites is restricted to a few strains.

Acetates↗
PubMed1990

Phylogenetic relationships among species of the genus Issatchenkia Kudriavzev.

The phylogenetic relatedness of Issatchenkia spp. was estimated from partial rRNA sequences in two regions of the large subunit and one region of the small subunit. I. terricola was the most divergent species of the genus, differing from other members by 18% nucleotide differences in the highly variable 25S-635 region. These data indicate Issatchenkia to be the most divergent ascomycetous yeast genus presently known.

Base Sequence↗
PubMed1980

A possible rôle for acid phosphatase in gamma-amino-n-butyrate uptake in Aspergillus nidulans.

Previously published work from another laboratory has shown that the mutation pacC-5 in the ascomycete Aspergillus nidulans leads to loss of an acid phosphatase (EC 3.1.3.2) activity and is probably located in the structural gene for this enzyme. Here, we show that, pleiotropically, pacC-5 considerably reduces gamma-amino-n-butyrate transport levels as shown both by direct uptake measurements and two kinds of growth tests. A reduction in expression of the permease specified by the gabA gene is almost certainly responsible for the gamma-amino-n-butyrate uptake defect in pacC-5 strains. pacC-5 does not reduce L-proline uptake, mainly mediated by the prnB permease, or beta-alanine uptake. This work and our previously published results suggest that, although it does not uniquely reduce gamma-amino-n-butyrate uptake, pacC-5 is highly selective in its effects on transport processes. It is therefore probable that the acid phosphatase specified by the pacC gene plays some rôle in the synthesis, membrane integration or functioning of a particular class of permeases. A rôle for acid phosphatases in membrane processes casts an intriguing new light on the fact that these enzymes are periplasmic and extracellular in many micro-organisms including A. nidulans.

Acid Phosphatase↗
PubMed1990

Chemotaxonomy of the genus Talaromyces.

Species of the ascomycetous genus Talaromyces have been examined for profiles of secondary metabolites on TLC. The greatest number of specific metabolites were produced on oatmeal-, malt extract- and yeast-extract sucrose agars. Profiles of intracellular secondary metabolites produced on oatmeal agar were specific for each species and provided a means of simple differentiation of the taxa. Examination of the most important species using high performence liquid chromatography (HPLC) allowed to solve some taxonomic problems. Known mycotoxins are produced by T. stipitatus (duclauxin, talaromycins, botryodiploidin), T. stipitatus chemotype II (emodin), T. panasenkoi (spiculisporic acid), T. trachyspermus (spiculisporic acid), T. macrosporus (duclauxin) and T. wortmannii (rugulosin). Wortmannin is produced by an atypical strain of T. flavus but not T. wortmannii. Several other secondary metabolites were discovered for the first time in the following species: Glauconic acid is produced by T. panasenkoi, T. ohiensis and T. trachyspermus; vermiculine by T. ohiensis; duclauxin by T. flavus var. macrosporus and the mitorubrins by T. flavus and T. udagawae. The profiles of secondary metabolites support the established taxonomy of the species based on morphology, showing the genetic stability of profiles of secondary metabolites in Talaromyces. Two new taxa are proposed: T. macrosporus comb. nov. (stat. anam. Penicillium macrosporum stat. nov.), and Penicillium vonarxii, sp. nov. for the anamorph of T. luteus.

Ascomycota↗
PubMed1984

DNA base composition and DNA relatedness among species of Trichosporon Behrend.

The nuclear DNA of 28 species (30 strains investigated) of yeasts classified currently or previously in the genus Trichosporon. was analysed for its molar percentage of guanine + cytosine (mol% G + C). This criterion, together with biochemical characteristics, suggested the separation of the organisms studied into two groups. The first group, which appears related to the Ascomycetes, includes thirteen species with a G + C content lower than 50 mol% (34.7-48.8), and lacks urease (except T. margaritiferum). The second group appears related to the Basidiomycetes and includes fifteen species with a G + C content higher than 50 mol% (57-64) and has the ability to hydrolyse urea. A DNA homology experiment with T. beigelii and twelve other species of the second group showed very low values of complementarity with T. beigelii-labeled DNA. All these species must be considered as taxa other than T. beigelii.

Ascomycota↗
PubMed1980

The distribution of the NADPH regenerating mannitol cycle among fungal species.

The mannitol cycle is an important NADPH regenerating system in Alternaria alternata. The cycle is built up to the following enzymes: mannitol 1-phosphate dehydrogenase, mannitol 1-phosphatase, mannitol dehydrogenase and hexokinase. The net reaction of one cycle turn is: NADH + NADP+ + ATP leads to NAD+ + NADPH + ADP + Pi. The enzymes needed for an operating cycle were found in Aspergillus, Botrytis, Penicillium, Pyricularia, Trichothecium, Cladosporium and Thermomyces all genera belonging to Fungi Imperfecti. The only genus of this class lacking the cycle was Candida. No genera from the classes Basidiomycetes and Phycomycetes showed any mannitol 1-phosphate dehydrogenase or mannitol 1-phosphatase activities. The genera investigated, belonging to Ascomycetes, Gibberella, Ceratocystis and Neurospora all lacked mannitol 1-phosphate dehydrogenase. It was concluded that the mannitol cycle is an important and widespread pathway for NADH oxidation and NADP+ reduction in the organisms belonging to the class Fungi Imperfecti.

Fungi↗
PubMed1986

A DNA polymerase activity with characteristics of a reverse transcriptase in Podospora anserina.

In the filamentous ascomycete fungus Podospora anserina, senescence is associated with dramatic changes of the juvenile mitochondrial genome. During senescence specific regions of the non-senescent genome are excised, ligated and amplified as a plasmid. In this paper, we report our studies on nuclear-mitochondrial extracts for the presence of RNA-dependent DNA polymerase activity (reverse transcriptase). In so-called middle aged mycelia of race A, we detected a DNA polymerase possessing properties of a reverse transcriptase. It prefers the ribopolymer templates poly(rA)-oligo(dT)12-18 and poly(rCm)-oligo(dG)12-18 over the deoxypolymer template poly(dA)-oligo(dT)12-18. It also uses natural rabbit globin mRNA as a template. The enzymatic activity can clearly be distinguished from a second DNA polymerase activity found in the same extracts of both young and middle aged mycelia.

Aging↗
PubMed1979

Deoxyribonucleic acid base composition and taxonomy in the genus Geotrichum Link.

The molar percentage of guanine + cytosine (% GC) in the DNA from 25 yeast-like fungi related to the genus Geotrichum has been measured. This criterion together with the biochemical characteristics allow the division of the species into 3 groups: one group resembling G. candidum (% GC: 31.5--42) and containing 8 imperfect and 6 perfect forms. In this group only G. capitatum has a lower % GC (31.5). A second group of 6 species resembling the genus Trichosporon (57--60%) and a third intermediate category of 4 species (42--53.5%) were observed. The GC-values correlate well with biochemical characters, e.g. the presence of urease, the number of organic substrates assimilated, and also with the presence of characters typical of the Ascomycetes or the Basidiomycetes.

Cytosine↗
PubMed1988

Nucleotide base sequence of the mitochondrial COIII gene of Schizophyllum commune.

The cytochrome oxidase subunit III gene (COIII) of the Badidiomycete S. commune has been identified, cloned, and sequenced. The gene contains no introns, is AT-rich (69%) and exhibits a high degree of similarity to sequences from Ascomycetes. While most mitochondrial genes use both TGA and TGG to specify tryptophan, the COIII gene of Schizophyllum uses TGG exclusively. Translation requires no deviation from the universal code.

Amino Acid Sequence↗
PubMed1995

Guest: a 98 bp inverted repeat transposable element in Neurospora crassa.

The region immediately 3' of histidine-3 has been cloned and sequenced from two laboratory strains of the ascomycete fungus Neurospora crassa; St Lawrence 74A and Lindegren, which have different derivations from wild collections. Amongst the differences distinguishing these sequences are insertions ranging in size from 20 to 101 bp present only in St Lawrence. The largest of these is flanked by a 3 bp direct repeat, has terminal inverted repeats (TIR) and shares features with several known transposable elements. At 98 bp, it may be the smallest transposable element yet found in eukaryotes. There are multiple copies of the TIR in the Neurospora genome, similar but not identical to the one sequenced. PCR amplification of Neurospora genomic DNA, using 26 bp of the TIR as a single primer, gave products of discrete sizes ranging from 100 bp to about 1.3 kb, suggesting that the element isolated (Guest) may be a deletion derivative of a family of larger transposable elements. Guest appears to be the first transposable element reported in fungi that is not a retrotransposon.

Base Sequence↗
PubMed1981

Trichosporonoides nigrescens sp. nov., a new xerophilic yeast-like fungus.

A new yeast-like fungus isolated from jam on two occasions is described as Trichosporonoides nigrescens. It is a true xerophile, able to grow at water activities at least as low as 0.75. For this reason, its carbon assimilation pattern was examined using both dilute (standard) and concentrated carbon sources: six to nine compounds not assimilated at the standard concentrations of 0.5% (0.001 to 0.1 mol/kg) were assimilated at 1.5 to 2.0 mol/kg. Cell wall and septal ultrastructure, DNA base ratios, and the nuclear cycle were examined to determine the generic and higher taxonomic affinities of this microorganism. All properties were consistent with its assignment to Trichosporonoides Haskins et Spencer. However, while ultrastructure indicated an affinity with the Basidiomycetes, the mitotic nuclear cycle and the xerophilic nature of this fungus suggested an Ascomycete affinity. The GC content (57%) is consistent with assignment to either. No teleomorphic state was found.

Carbohydrate Metabolism↗
PubMed1986

Molecular cloning and characterization of the trpC gene from Penicillium chrysogenum.

We cloned the Penicillium chrysogenum trpC gene from a genomic library by complementation of an Escherichia coli trpC mutant lacking phosphoribosylanthranilate isomerase activity. The gene encodes a 2.7 kb poly(A)+ RNA. We localized the gene by sequence analysis in a 2.9 kb DNA insert found in the smallest plasmid selected from the library. Sequence data strongly suggest that the organization of the gene is similar to that described in other Ascomycetes. We found that a DNA fragment which codes only for the carboxy-terminal portion of the polypeptide is sufficient for complementation of the E. coli trpC9830 mutation.

Anthranilate Synthase↗
PubMed1988

Organization of ribosomal RNA genes in the fungus Cochliobolus heterostrophus.

The genes encoding the 17S, 5.8S and 25S ribosomal RNAs in the Ascomycete Cochliobolus heterostrophus were cloned and analyzed. They are arranged in tandemly repeated units (rDNA) either 9.0 or 9.15 kilobases in length, depending upon the strain. The 5S rRNA genes are not part of the tandemly repeated rDNA. Instead, many and perhaps all of the 5S genes are dispersed in the genome, as they are in the fungi Neurospora, Aspergillus and Schizosaccharomyces. Comparative restriction maps of the rDNA from C. heterostrophus and other filamentous fungi and yeasts are presented. A survey of rDNAs from twenty-three field isolates of C. heterostrophus collected worldwide demonstrated that each isolate has one or the other of two rDNA forms, which differ in length and in the presence or absence of at least three restriction enzyme sites. The differences are all located in spacer DNA outside the coding regions for the rRNA genes. Heterogeneity in the rDNA repeat was not observed within any single isolate. The copy number of the rRNA gene cluster in C. heterostrophus is approximately 130 per haploid genome.

Ascomycota↗
PubMed1984

The mitochondrial genome of the fission yeast Schizosaccharomyces pombe. 2. Localization of genes by interspecific hybridization in strain ade7-50h- and cloning of the genome in small fragments.

A series of 18 small overlapping restriction fragments has been cloned, covering the complete mitochondrial genome of Schizosaccharomyces pombe. By hybridizing mitochondrial gene probes from Saccharomyces cerevisiae and Neurospora crassa with restriction fragments of Schizosaccharomyces pombe mitochondrial DNA, the following homologous genes were localized on the mitochondrial genome of S. pombe: cob, cox1, cox2 and cox3, ATPase subunit 6 and 9 genes, the large rRNA gene and both types of open reading frames occurring in mitochondrial introns of various ascomycetes. The region of the genome, hybridizing with cob exon probes is separated by an intervening sequence of about 2500 bp, which is homologous with the first two introns of the cox1 gene in Saccharomyces cerevisiae (class II introns according to Michel et al. 1982). Similarly, in the cox1 homologous region, which covers about 4000 bp, two regions were detected hybridizing with class I intron probes, suggesting the existence of two cox1 introns in Schizosaccharomyces pombe. Hybridization with several specific exon probes with a determined order has revealed that cob, cox1, cox3 and the large rRNA gene are all transcribed from the same DNA strand. The low intensities of hybridization signals suggest a large evolutionary distance between Schizosaccharomyces pombe and Saccharomyces cerevisiae or Neurospora crassa mitochondrial genes. Considering the length of the mitochondrial DNA of Schizosaccharomyces pombe (about 19.4 kbp) and the expected length of the localized genes and intron sequences there is enough space left for encoding the expected set of tRNAs and the small rRNA gene. The existence of leader-, trailer-, ori- and spacer sequences or further unassigned reading frames is then restricted to a total length of about 3000 bp only.

Ascomycota↗
PubMed1982

Antifungal activity of some Discomycetes. I. Biological spectrum of Ciboria rufo-fusca (Weberb.) Sacc.

The antifungal activity was investigated in culture filtrates of 131 strains (41 genera and 104 species) of Ascomycetes--Discomycetes by testing against 6 fungal species which caused diseases in man. The anti-fungal spectrum was established for a Ciboria rufo-fusca strain, the only one found to inhibit all test organisms. This strain was also active against several gram-positive and gram-negative bacteria.

Anti-Bacterial Agents↗