Filobasidium capsuligenum nov. comb.

Leucosporidium capsuligenum Fell et al. is classified in the genusFilobasidium Olive sinceTilletia-like basidia were discovered growing out from a dicaryotic mycelium with clamp connections. The speciesFilobasidium floriforme andFilobasidium capsuligenum are compared morphologically and physiologically. The author is indebted to Dr. G. Kraepelin who place the original culture, isolated from soil with dead leaves, to the disposal of the Centraalbureau voor Schimmelcultures, and to Dr. J. A. von Arx who provided him with the singlespore isolates.     

Characterization of yeasts isolated from red wine surface film

We have isolated 6 morphologically different axenic yeast cultures from the film surface of red wine. Based on morphological, physiological and biochemical characteristics we have identified the strains as follows: isolates1–4 are morphologically different strains of the anamorph basidiomycetous film-forming yeastCandida humicola (Daszewska) Diddens etLodder, syn.Apiotrichum humicola (Daszewska) von Arx Weijman. Isolates5 and6 belong to the genusSaccharomyces of the associated speciesS. cerevisiœ (isolate5 originallyS. bayanus, isolate6 S. capensis). These do not participate in the surface film formation.     

A cytochrome P450 class I electron transfer system from Novosphingobium aromaticivorans

Cytochrome P450 (CYP) enzymes of the CYP101 and CYP111 families from Novosphingobium aromaticivorans are heme monooxygenases that catalyze the hydroxylation of a range of terpenoid compounds. CYP101D1 and CYP101D2 oxidized camphor to 5-exo-hydroxycamphor. CYP101B1 and CYP101C1 oxidized β-ionone to predominantly 3-R-hydroxy-β-ionone and 4-hydroxy-β-ionone, respectively. CYP111A2 oxidized linalool to 8-hydroxylinalool. Physiologically, these CYP enzymes could receive electrons from Arx, a [2Fe-2S] ferredoxin equivalent to putidaredoxin from the CYP101A1 system from Pseudomonas putida. A putative ferredoxin reductase (ArR) in the N. aromaticivorans genome, with high amino acid sequence homology to putidaredoxin reductase, has been over-produced in Escherichia coli and found to support substrate oxidation by these CYP enzymes via Arx with both high activity and coupling of product formation to NADH consumption. The ArR/Arx electron-transport chain has been co-expressed with the CYP enzymes in an E. coli host to provide in vivo whole-cell substrate oxidation systems that could produce up to 6.0 g L⁻¹ of 5-exo-hydroxycamphor at rates of up to 64 μM (gram of cell dry weight)⁻¹ min⁻¹. These efficient biocatalytic systems have potential uses in preparative scale whole-cell biotransformations.     

Pathogenicity to western larch (Larix occidentalis) of two fungi, Ophiostoma pseudotsugae and Leptographium abietinum, associated with the Douglas fir beetle (Coleoptera: Scolytidae)

1 Pole-sized, live western larch Larix occidentalis Nutt. were mass-inoculated with Ophiostoma pseudotsugae (Romb.) von Arx or Leptographium abietinum (Peck) Wingf., two blue-stain fungi associated with the Douglas fir beetle Dendroctonus pseudotsugae Hopkins, to assess their pathogenicity. 2 Inoculation with O. pseudotsugae resulted in significantly greater percentages of necrotic phloem compared with L. abietinum inoculations. 3 The percentage of occluded sapwood was significantly greater after L. abietinum inoculations compared with O. pseudotsugae inoculations. 4 Within the inoculation band, all trees had more than 60% functional sapwood 4 months after treatment. 5 The results suggest that western larch can successfully limit colonization by O. pseudotsugae and L. abietinum. 6 The inability of the fungi to thrive in live western larch may be a factor in the consistent failure of Douglas fir beetle broods in this host tree species.     

The Cytosolic J-protein, Jjj1, and Rei1 Function in the Removal of the Pre-60 S Subunit Factor Arx1

Although the biogenesis of ribosomal subunits occurs predominantly in the nucleus, final remodeling steps take place in the cytosol. One cytosolic step has two components: 1) the removal of the maturation factor Arx1, which transits from the nucleus to the cytosol with the pre-60 S subunit, and 2) its subsequent transport back into the nucleus. Two cytosolic proteins, Rei1 and Jjj1, are required, but their individual contributions to this step are not understood. Here we report that Rei1 and Jjj1 directly interact. This interaction is mediated by a C-terminal segment of Jjj1 encompassing a region rich in charged residues, flanked by C₂H₂-type zinc fingers. Deletion of the charged region results in defects in 60 S subunit biogenesis in vivo. In addition, we report resolution of an apparent contradiction in the literature regarding the association of Arx1 with the pre-60 S subunit in the absence of Rei1. The association of Arx1 with ribosomes is sensitive to the concentration of magnesium ions when Rei1 is absent. At near physiological concentrations, Arx1 remains associated with the pre-60 S particle, as it does in the absence of Jjj1; at higher concentrations, Arx1 dissociates in the absence of Rei1 but not in the absence of Jjj1. As both Rei1 and Jjj1 are required for dissociation of Arx1 from the pre-60 S subunit, and the region of Jjj1 that mediates interaction with Rei1 is required in vivo for 60 S subunit biogenesis, our data support the idea that the primary role of both Rei1 and Jjj1 is the first step of the Arx1 removal/recycling process.     

<Emphasis Type="Italic">Cylindrosporella</Emphasis> on betulaceous trees in Japan

Three Cylindrosporella species on the leaves of betulaceous trees – C. carpini, C. coryli, and C. microsperma – were first reported from Japan. The genus Cylindrosporella is sometimes treated as congeneric with Asteroma; however, we considered these to differ based on conidial morphology following the concept of Arx. The genus Cylindrosporella is characterized by one-celled, filiform or fusiform, small conidia that are often curved, have hyaline, thin walls, and are produced from phialidic conidiogenous cells in subcuticular, fiat acervuli. The three species are distinguished from each other on the basis of conidium size. Received: September 27, 2001 / Accepted: November 5, 2001     

Arx acts as a regional key selector gene in the ventral telencephalon mainly through its transcriptional repression activity

The homeobox-containing gene Arx is expressed during ventral telencephalon development and required for correct GABAergic interneuron tangential migration from the ganglionic eminences to the olfactory bulbs, cerebral cortex and striatum. Its human ortholog is associated with a variety of neurological clinical manifestations whose symptoms are compatible with the loss of cortical interneurons and altered basal ganglia-related activities. Herein, we report the identification of a number of genes whose expression is consistently altered in Arx mutant ganglionic eminences. Our analyses revealed a striking ectopic expression in the ganglionic eminences of several of these genes normally at most marginally expressed in the ventral telencephalon. Among them, Ebf3 was functionally analyzed. Thus, its ectopic expression in ventral telencephalon was found to prevent neuronal tangential migration. Further, we showed that Arx is sufficient to repress Ebf3 endogenous expression and that its silencing in Arx mutant tissues partially rescues tangential cell movement. Together, these data provide new insights into the molecular pathways regulated by Arx during telencephalon development.     

Molecular Characterization of a Class I P450 Electron Transfer System from Novosphingobium aromaticivorans DSM12444

Cytochrome P450 (CYP) enzymes of the CYP101 and CYP111 families from the oligotrophic bacterium Novosphingobium aromaticivorans DSM12444 are heme monooxygenases that receive electrons from NADH via Arx, a [2Fe-2S] ferredoxin, and ArR, a ferredoxin reductase. These systems show fast NADH turnovers (k_cat = 39–91 s⁻¹) that are efficiently coupled to product formation. The three-dimensional structures of ArR, Arx, and CYP101D1, which form a physiological class I P450 electron transfer chain, have been resolved by x-ray crystallography. The general structural features of these proteins are similar to their counterparts in other class I systems such as putidaredoxin reductase (PdR), putidaredoxin (Pdx), and CYP101A1 of the camphor hydroxylase system from Pseudomonas putida, and adrenodoxin (Adx) of the mitochondrial steroidogenic CYP11 and CYP24A1 systems. However, significant differences in the proposed protein-protein interaction surfaces of the ferredoxin reductase, ferredoxin, and P450 enzyme are found. There are regions of positive charge on the likely interaction face of ArR and CYP101D1 and a corresponding negatively charged area on the surface of Arx. The [2Fe-2S] cluster binding loop in Arx also has a neutral, hydrophobic patch on the surface. These surface characteristics are more in common with those of Adx than Pdx. The observed structural features are consistent with the ionic strength dependence of the activity.     

Characterization of the strain <Emphasis Type="Italic">Monascus floridanus</Emphasis> P. F. Cannon &; E. L. Barnard,isolated from aviation fuel

A fungus was isolated from aviation fuel and identified as Monascus floridanus P.F. Cannon & E.L. Barnard (FR827895) according to its morphological and genetic properties. The isolate has some properties that are unusual for the type strain, including a prominent stripe on one of the sides of the ascospores and occurrence, along with the known Basipetospora-type thallic conidia, of the phialophora-like spore formation. The isolated strain Monascus floridanus, like the known kerosene fungus Hormoconis resinae (Lindau) Arx & G.A. de Vries, is capable of active growth in aviation fuel.     

Sympodiomyces gen. n., a yeast-like organism from southern marine waters

Sympodiomyces gen. n. is described with the single speciesSympodiomyces parvus sp. n. The distinguishing characteristic of this yeast-like genus is the method of asexual reproduction: conidia are produced on a conidiophore that develops sympodially. A sexual stage has not been observed, therefore the genus is placed among the Fungi Imperfecti, family Cryptococcaceae.Contribution No. 1364 from the Rosenstiel School of Marine and Atmospheric Science, University of Miami, Florida.The authors gratefully acknowledge Dr. Jan Kohlmeyer, Univ. of North Carolina, Morehead City, North Carolina; Dr. R. T. Moore, North Carolina State Univ. at Raleigh; Dr. H. J. Phaff, Univ. of California at Davis; Miss W. Ch. Slooff and Mr. D. Yarrow, CBS, Delft, Netherlands; Dr. K.Tubaki, Institute for Fermentation, Osaka, Japan; and Dr. J. A. von Arx, C.B.S., Baarn, for examining cultures ofS. parvus. Dr. D. P. Rogers, Univ. of Illinois, Urbana, Ill, prepared the generic Latin diagnosis. Mr. Steven Y. Newell and Mr. A. Weiner, Univ. of Miami, assisted in obtainingEltanin collections. This study was supported by the National Science Foundation through the Office of Antarctic Programs Grant No. GA 13675.     

Conidial development in selected ambrosial species of the genus <Emphasis Type="Italic">Raffaelea</Emphasis>

Conidiogenesis of the type species and two additional species of the genus Raffaelea Arx & Hennebert are described. In contrast to previous conclusions based on light microscopy that indicate sympodial production of the conidia, we found that conidium development was by annellidic percurrent proliferation in the type species Raffaelea ambrosiae, as well as in Raffaelea arxii and Raffaelea albimanens. Consequently, this mode of conidium development is similar to the conidiogenesis of anamorphs within the Ophiostomatales, but distinguished by sporodochia formed within the genus Raffaelea. These findings reduce the differences between Raffaelea and other anamorphs with annellidic percurrent proliferation of the conidiogenous cells within the Ophiostomatales to different conidiomata and conidiophores, and they support previous reports of the close phylogenetic relationship between Raffaelea and Ophiostoma.     

Contribution to the knowledge of the genus Phyllopodopsyllus T. Scott (Copepoda,Harpacticoida) from Africa with description of two new species

Two new species of marine, sand-dwelling harpacticoids are described: Phyllopodopsyllus pallaresae n. sp. from Namibia, and P. hartmannorum n. sp. from Tanzania. The hitherto unknown male of P. xenus (Kunz) is described from Namibia. Further remarks are made on P. furciger Sars from Tanzania.Zwei neue sandbewohnende Harpacticoiden-Arten werden beschrieben: Phyllopodosyllus pallaresae n. sp. von Namibia und Phyllopodopsyllus hartmannorum n. sp. von Tansania. Außerdem wird das bisher unbekannte Männchen von Phyllopodopsyllus xenus (Kunz) von Namibia beschrieben. Morphologische Merkmale von Phyllopodopsyllus furciger Sars werden anhand eines Fundes von Tansania ergänzt.     

Physiological and biochemical properties of two strains ofCephalosporium chrysogenum

Two morphologically identical strains ofCephalosporium chrysogenum were compared with respect to physiological and biochemical properties. Similar patterns of carbohydrate and hydrocarbon utilization were noted for both strains. Each strain was enzymatically active against the following substrates: beef fat, arbutin, urea, casein, lignin, and cellulose. A yellow pigment was produced by both strains in various agar media. Vitamins were not essential for growth. Each organism could be cultivated in the presence of 40% glucose. Both strains yielded antibiotics inhibiting the growth of gram-positive and gram-negative bacteria. Chromatography of cell hydrolysates of theC. chrysogenum strains revealed the presence of ribose, glucose and galactose.The author expresses his gratitude to Prof. Dr. T. O. Wikén of the Delft University of Technology, and to Dr. J. A. von Arx of the Centraalbureau voor Schimmelcultures, Baarn, for their cooperation in making this investigation possible. Sincere thanks are due to Dr. W. Gams of the Centraalbureau for supplying both strains ofC. chrysogenum.This work was supported by Public Health Service special research fellowship 1-F3-AI-37, 152-01 from the National Institute of Allergy and Infectious Diseases, U.S.A.     

The mycoflora and incidence of aflatoxin,zearalenone and sterigmatocystin in dairy feed and forage samples from Eastern India and Bangladesh

The mycoflora of a range of mixed ruminant feed and forage samples collected in Eastern India and Bangladesh were determined. Most fungi isolated from the samples were those associated with low moisture contents. Several potentially mycotoxigenic fungi and thermotolerant species were present particularly in the rice straw. The most frequently isolated fungi were: Aspergillus versicolor (Vuill.) Tiraboschi, Penicillium citrinum Thorn, Eurotium species, Wallemia sebi (Fr.) v. Arx, Aspergillus penicilloides Speg. and yeasts. Fusarium moniliforme Sheldon and Cladosporium species were prevalent in straw but not other feeds. Levels of certain individual fungi, particularly thermotolerant types, were higher in Bangladesh rice straw although overall counts were similar to those of the Indian samples. Mycotoxin analyses for aflatoxins, zearalenone and sterigmatocystin were carried out. Aflatoxins were detected in significant amounts in some feed samples from Eastern India but not in rice straw from India and Bangladesh. Zearalenone occurred in a Paspalum straw sample and three other feed samples from India and sterigmatocystin was detected in three rice straw samples from Bangladesh.     

The controversy on the ancestral arsenite oxidizing enzyme; deducing evolutionary histories with phylogeny and thermodynamics

The three presently known enzymes responsible for arsenic-using bioenergetic processes are arsenite oxidase (Aio), arsenate reductase (Arr) and alternative arsenite oxidase (Arx), all of which are molybdoenzymes from the vast group referred to as the Mo/W-bisPGD enzyme superfamily. Since arsenite is present in substantial amounts in hydrothermal environments, frequently considered as vestiges of primordial biochemistry, arsenite-based bioenergetics has long been predicted to be ancient. Conflicting scenarios, however, have been put forward proposing either Arr/Arx or Aio as operating in the ancestral metabolism. Phylogenetic data argue in favor of Aio whereas biochemical and physiological data led several authors to propose Arx/Arr as the most ancient anaerobic arsenite metabolizing enzymes. Here we combine phylogenetic approaches with physiological and biochemical experiments to demonstrate that the Arx/Arr enzymes could not have been functional in the Archaean geological eon. We propose that Arr reacts with menaquinones to reduce arsenate whereas Arx reacts with ubiquinone to oxidize arsenite, in line with thermodynamic considerations. The distribution of the quinone biosynthesis pathways, however, clearly indicates that the ubiquinone pathway is recent. An updated phylogeny of Arx furthermore reinforces the hypothesis of a recent emergence of this enzyme. We therefore conclude that anaerobic arsenite redox conversion in the Archaean must have been performed in a metabolism involving Aio.     

UBER DEN BIOTEST VON BACILLUS THURINGIENSIS-EXOTOXIN MIT DROSOPHILA MELANOGASTER

Summary Larvae of Drosophila melanogaster (Meigen), placed as eggs on the substrate, are suitable for bioassay of the toxic qualities of the supernatant from culture media of Bacillus thuringiensis Berliner. Only supernatants of active strains of B. thuringiensis var. thuringiensis contained a thermostable exotoxin and, therefore, caused significant mortality. Supernatants prepared from cultures of other varieties of B. thuringiensis, however, as well as from cultures of Bacillus cereus had no effect (Tab. I). Pure preparations of the spore-endotoxin-complex of B. thuringiensis ded not kill larvae of Drosophila melanogaster even in doses of 0.16 per cent of the medium (Tab. II). According to the qualitative classification of commercial B. thuringiensis-preparations by Burgerjon, Biospor 2802 (Farbwerke Hoechst, Germany), belongs to group I, whereas Bakthane L-69 (Rohm & Haas, USA) is representative of group II.

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Über den Biotest von Bacillus thuringiensis-Exotoxin mit drosophila melanogaster

Zusammenfassung Zur Prüfung der toxischen Qualitäten von Kulturüberständen von Bacillus thuringiensis-Kulturen dienten Larven von Drosophila melanogaster. Es wurden abgezählte mengen von Eiern auf das kontaminierte Substrat aufgebracht und am Ende des Versuchs die entwickelten Imagines registriert. Nur Überstände aktiver Stämme von B. thuringiensis var. thuringingiensis enthielten ein thermostabiles Exotoxin und bewirkten eine entsprechende Mortalität. Kultur-überstände anderer Varietäten von B. thuringiensis wie auch von Bacillus cereus hatten keine Wirkung (Tab. I). Gereinigte Präparate des Sporen-Endotoxin-Komplexes von B. thuringiensis waren selbst in Dosen von 0,16% des Mediums unwirksam (Tab. II). Entsprechend der qualitativen Klassifikation von industriellen B. thuringiensis-Präparaten nach Burgerjon gehört Biospor 2802 (Farbwerke Hoechst, Deutschland) zur Gruppe I, während Bakthane L-69 (Rohm & Haas, USA) für die Gruppe II repräsentativ ist.

     

A scanning electron microscope study of interactions between micro-organisms andGaeumannomyces graminis (Syn.Ophiobolus graminis) on wheat roots

Roots of wheat grown in unsterilized sand inoculated withGaeumannomyces graminis (Sacc.) von Arx and Olivier were examined by scanning electron microscopy. Healthy roots had a mucilaginous covering and were sparsely colonized by bacteria, but asG. graminis colonized the roots the mucilage disappeared and the numbers of bacteria on the surface increased. Lysis of the hyphae occurred, apparently caused by bacteria that colonized the hyphae. Inoculation of wheat in axenic culture with a strain ofPseudomonas fluorescens that was antagonistic toG. graminis in agar gave some protection against the pathogen; lysis of hyphae was observed where protection occurred.