Trichophyton rubrum (Castellani) var. flava,var. nova a yellow pigment forming Trichophyton rubrum

Summary and Conclusions A hitherto unknown variant ofT. rubrum var.flava is described which besides its yellow pigment has the following characteristics different fromT. rubrum (Castellani). A much slower growth and a smaller diameter of the giant culture and an appreciable difference in the light absorption curve of the extracted pigment.     

Differentiation of trichophyton rubrum from trichophyton mentagrophytes

Conclusions Of the several morphological and physiological criteria that have been proposed to identifyTrichophyton rubrum andTrichophyton mentagrophytes differentially, only the hair invasion test agrees with the immunological results reported here.A typical strain ofT. rubrum andT. mentagrophytes was obtained from the Centraalbureau voor Schimmelcultures (Netherlands) and was used as reference strain. All isolates that did not invade hair shafts (in vitro) and that produced three precipitate lines in agargel diffusion tests against anti-T. rubrum serum (refence strain, Tr-1) were placed in one group. These isolates all also produced a red undersurface pigment and macroconidia with long parallel sides. They were labledT. rubrum.Other isolates that did invade hair shafts, and produced only two precipitate lines against anti-T. rubrum serum were placed in another group and were labeledT. mentagrophytes. These isolates had variable characteristics of pigment production, colony and conidial morphology.The antigenic studies thus corroborate the validity of the hair invasion test. The hair invasion test will probably remain in wider use because of its simplicity.     

Trennung der Thylakoidbausteine einiger Athiorhodaceae durch Gelelektrophorese

Zusammenfassung Thylakoide vonRhodospirillum rubrum, Rhodopseudomonas viridis undRhodopseudomonas capsulata wurden durch Behandlung mit Phenol-Ameisensäure in makromolekulare, in der Gelelektrophorese wandernde Fraktionen aufgespalten. Dabei ergaben sich vier deutlich hervortretende Hauptfraktionen, die zum Teil noch in Unterfraktionen aufzulösen sind.BeiRhodospirillum rubrum wurden neben den Thylakoiden auch noch Rohfraktionen der cytoplasmatischen Membran und der Zellwand mit der gleichen Methode untersucht. Alle Strukturen unterschieden sich deutlich voneinander in der Zahl und Wanderungsgeschwindigkeit ihrer Banden.Aus einer Dunkelkultur vonRhodospirillum rubrum, in der durch Absenken des Sauerstoffpartialdruckes die Thylakoidmorphogenese und Pigmentsynthese induziert worden war, wurde die Gesamtmembranfraktion isoliert, durch Behandlung mit Phenol-Ameisensäure dissoziiert und gelelektrophoretisch aufgetrennt. In den Pherogrammen war deutlich von Beginn der Induktion an eine Zunahme thylakoidspezifischer Bandenmuster zu erkennen. Ein Ausplanimetrieren der Absorptionskurven ergab, daß das Wachstum der Thylakoidstrukturen exponentiell erfolgte. Unter den Bedingungen der Kultur wurde nach etwa 8 Std ein Plateau in der Ausbildung der thylakoidspezifischen Strukturen erreicht. Die Kurve der Bacteriochlorophyllsynthese nahm einen etwas anderen Verlauf. Sie war im Bereich des exponentiellen Wachstums der Thylakoidstrukturen stärker gekrümmt, bog dann aber später ebenfalls ab, so daß sie nach 8–10 Std parallel zu den Thylakoiden verlief.

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Fractionation of thylakoid-components of some athiorhodaceae by polyacrylamide-gel electrophoresis

Summary Thylakoids (chromatophores) ofRhodospirillum rubrum, Rhodopseudomonas viridis, andRhodopseudomonas capsulata were fractionated after treatment with phenol-formic acid-water (2:1:1) by gel electrophoresis in four main fractions. The pattern of maxima was different in the three species.Crude preparations of cytoplasmic membrane and cell wall ofR. rubrum differ from the thylakoids in their pattern of electrophoresis distribution.Crude total membrane fractions were isolated from cells ofR. rubrum, which was induced to synthesize bacteriochlorophyll and thylakoids.Fractionation of the membranes by the above mentioned method shows very clearly that after induction of morphogenesis the thylakoid-specific membrane units are increased exponentially.

     

ATP-synthetase complex (F1F0) from Escherichia coli. Purification and characterization of subunits A and B of the F0 part

An intact B890 light-harvesting pigment—protein complex has been obtained from Rhodospirillum rubrum strain S1. We show that this complex contains two types of low-M_r polypeptide. Both these polypeptides are present in the intact chromatophore membrane. Analysis of the pigment content of this complex suggests that per pair of polypeptides the complex contains 2 molecules of bacteriochlorophyll and one molecule of carotenoid.     

A Study on Stability of Phenotype and Genotype of Trichophyton rubrum

Objective: To explore the stability of phenotype and genotype in Trichophyton rubrum. Methods: All the strains were cultured on Sabouraud’s dextrose agar slopes, and identified to species level. Strains isolated recently were subcultured on Sabouraud agar slopes four times at an interval of 4 weeks. DNA was extracted with CTAB method. A probe consisting of 3′ end of 18S rDNA, adjacent ITS1, 5.8S rDNA and ITS2 regions was amplified from template DNA of the T. rubrum standard strain using fungal universal primers NS5 and ITS4, labelled by P³² and hybridized with EcoR I-digested T. rubrum genomic DNA. Results: (1) Four phenotypes were isolated from 207 T. rubrum strains, with downy type (45.4%) in the first place, and granular type not found. After 1 year of conservation, 54 strains showed morphological variations with the total variation rate of 26.1%. (2) Eleven strains showed variations in colony morphology or pigment upon subculture. (3) AP-PCR analysis of 10 T. rubrum isolates and one T. rubrum standard strain showed similar DNA patterns with main bands at 2.2, 1.7, 1.3, 0.9 and 0.7 kb. No changes in DNA pattern were found upon subculture. (4) Hybridization analysis revealed that all the 11 T. rubrum strains presented three bands and were identified into two types (2.4, 3.9, 5.9 kb and 2.4, 4.4, 6.5 kb). No changes in band pattern were found upon subculture. Conclusions: Phenotype of T. rubrum was instable and the colonial morphology and pigment easily changed during conservation or subculture, while its genotype was relatively stable.     

In vitro hair cultures for differentiating between atypical isolates ofTrichophyton mentagrophytes andTrichophyton rubrum

Summary Isolates ofT. mentagrophytes andT. rubrum are encountered that cannot be distinguished from each other solely on the basis of morphological criteria.Since these two species fundamentally differ in the manner in which they attack hairin vitro, this property can be used as a diagnostic aid, when correlated with their morphologic characteristics as developed on a variety of media. T. mentagrophytes radially penetrates hair segments immersed in water forming wedge-shaped perforations.T. rubrum does not perforate hair.The method of determining the ability or inability ofT. mentagrophytes orT. rubrum to perforate hair and the use of this test in identifying those species are described.     

Die Alkoholkomponente des Bacteriochlorophyll a aus Rhodospirillum rubrum

Summary The esterifying alcohol of the bacteriochlorophyll a from Rhodospirillum rubrum was shown to be trans-trans-geranylgeraniol. Mass spectra of the corresponding bacteriopheophytins are used to determine the content and ratio of bacteriochlorophyll a_P and bacteriochlorophyll a_Gg in various strains of phototrophic bacteria.     

Self-assembled monolayer of light-harvesting core complexes of photosynthetic bacteria on an amino-terminated ITO electrode

Light-harvesting antenna core (LH1-RC) complexes isolated from Rhodospirillum rubrum and Rhodopseudomonas palustris were successfully self-assembled on an ITO electrode modified with 3-aminopropyltriethoxysilane. Near infra-red (NIR) absorption, fluorescence, and IR spectra of these LH1-RC complexes indicated that these LH1-RC complexes on the electrode were stable on the electrode. An efficient energy transfer and photocurrent responses of these LH1-RC complexes on the electrode were observed upon illumination of the LH1 complex at 880 nm.     

Die Ausscheidung von partikelgebundenen Bacteriochlorophyllvorstufen durch die Mutante F9 von Rhodospirillum rubrum

Zusammenfassung Eine bacteriochlorophyllfreie Mutante von Rhodospirillum rubrum wird beschrieben. Diese Mutante scheidet die Bacteriochlorophyllvorstufen Phaeophorbid a und 2-Devinyl-2--Hydroxyäthyl-Phaeophorbid a unter semiaeroben Bedingungen in das Kulturmedium aus. Beide Pigmente sind mit einem Trägermolekül zu einem Komplex verbunden. Die Analyse des Komplexes ergab folgende Zusammensetzung: 49% Protein, 30% Pigment, 11% Lipide, 3% Zucker, sowie eine geringe Menge Phosphor (0,2%). Die Aminosäurezusammensetzung des Proteinanteils wird angegeben. Die Fettsäuren werden gaschromatographisch bestimmt. Die Zuckerkomponente ist anders zusammengesetzt als das Lipopolysaccharid aus Rhodospirillum rubrum. Das Molekulargewicht der kleinsten Proteinuntereinheit beträgt 16500, das Molekulargewicht des Pigmentkomplexes ergibt sich daraus mit 34000. Typische Thylakoide werden in der Mutante nicht ausgebildet. Die Notwendigkeit einer ungestört ablaufenden Bacteriochlorophyllsynthese für die normale Thylakoidmorphogenese wird diskutiert.

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The production of particle bound bacteriochlorophyll precursors by the mutant F9 of Rhodospirillum rubrum

Summary A mutant strain of Rhodospirillum rubrum is described which does not form bacteriochlorophyll. This mutant strain excretes the bacteriochlorophyll precursors pheophorbide a and 2-devinyl-2-hydroxyethylpheophorbide a into the cultural medium, when it is cultured under low aeration in the dark. The pigments were identified spectroscopically. Both of the pigments are bound to a macromolecular compound. The complete macromolecule was shown to be composed of 49% protein, 30% pigments, 11% lipid, 3% sugar, and a trace of phosphorus (0.2%). The amino acid composition of the protein as well as the fatty acid pattern of the lipid are presented. The percent portions of fatty acids in whole cells are quite different from that of the pigment complex. The composition of the sugar moiety was demonstrated to be different from that of the lipopolysaccharide of Rhodospirillum rubrum. The molecular weight of the smallest subunit of the protein is 16,500. This suggests a molecular weight of 34,000 for the total pigment complex. Typical thylakoids were not observed in cells of the mutant strain. The necessity of an unblocked bacteriochlorophyll synthesis for the normal thylakoid morphogenesis is discussed.

     

Untersuchungen zur Substruktur der “Chromatophoren” von Rhodospirillum rubrum und Rhodospirillum molischianum

Summary Electron microscopy of ultrathin sections reveals that in the photosynthetic bacterium Rhodospirillum molischianum Giesberger numerous discrete discs, the chromatophores, are developed. The chromatophores are 300 m in diameter and have a thickness of 70 to 80 m. In their substructure they show piled-up plates, the lamellae. The dense plates are about 45 Å thick with less dense interspaces of 50 Å. The small vesicular chromatophores of Rhodospirillum rubrum Esmarch are surrounded by membranes and have a diameter of about 70 m. The chromatophores of both species are arranged at the periphery of the cell. A definition of the two strains on the fundamentals of morphological features is given. The absorption-spectra of the pigment extracts exhibit characteristic differences.     

Untersuchungen über die Membran-Proteine bei Rhodospirillum rubrum

Zusammenfassung Membranen aus aeroben Dunkelkulturen von Rhodospirillum rubrum und Thylakoide wurden nach Behandlung mit Phenol-Harnstoff-Eisessig (2:1,2:1, w/w/v) in ihre Proteinbausteine zerlegt und durch Gelelektrophorese in Polyacrylamid getrennt. Die Muster der Proteinkomponenten beider Membransysteme unterschieden sich nur geringfügig. Eine dem mitochondrialen Struktur-protein entsprechende Fraktion wurde aus Thylakoiden isoliert. Nach Aufspaltung dieser Fraktion mit Phenol-Harnstoff-Eisessig und anschließender Elektrophorese konnten verschiedene Proteine in ihr festgestelt werden. Diese Proteine waren sämtlich in 8 M Harnstoff löslich. Die Folgerungen aus diesen Ergebnissen für den Membranaufbau bei Rhodospirillum rubrum werden diskutiert.

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Investigations on membrane proteins in Rhodospirillum rubrum

Summary Membrane fractions from aerobically dark-grown Rhodospirillum rubrum and chromatophores (=thylakoids) were split into their protein subunits by phenol-urea-acetic acid (2:1.2:1, w/w/v) and separated by polyacrylamide gel electrophoresis. The spectra of the proteins of both types of membranes differed only slightly. A fraction was isolated from chromatophores (=thylakoids) by the methods for the homogeneous mitochondrial structural protein. When this fraction was split by phenol-urea-acetic acid and separated by gel electrophoresis several proteins could be identified. All of these proteins were soluble in 8 M urea. The consequences of these findings are discussed with respect to the composition of membranes in Rhodospirillum rubrum.

     

Lineages Within the Trichophyton rubrum Complex

The most important species of the Trichophyton rubrum group are T. rubrum, causing mainly skin and nail infections, and T. violaceum which is mostly scalp-associated. The status of a third species, T. soudanense, has been under debate. With a polyphasic approach, using molecular phylogenetic techniques, MALDI-TOF mass spectrometry and physiological and morphological analysis, we re-evaluated the T. rubrum complex. Our results support four genetic lineages within the complex each with a distinct morphology and identifiable via MALDI-TOF MS: T. rubrum, T. violaceum, T. soudanense and the T. yaoundei clade. However, ITS and Bt2 sequencing data could not confirm these taxa as four monophyletic species. Our results also suggest that strains formerly identified as T. kuryangei and T. megninii should be considered in future taxonomic studies.

     

Differences in the control of bacteriochlorophyll formation by light and oxygen

Control of bacteriochlorophyll formation was studied with continuous cultures of Rhodospirillum rubrum, Rhodopseudomonas sphaeroides, and Rhodopseudomonas capsulata. Oxygen controlled specific bacteriochlorophyll contents of the three species in a hyperbolical fashion irrespective of the presence of light. In Rps. sphaeroides, this applied to oxygen concentrations above 16% air saturation of the medium while at lower oxygen concentrations control followed a kinetics with negative cooperativity. Cell protein formation of R. rubrum and Rsp. sphaeroides was independent of oxygen concentrations while protein formation of Rps. capsulata increased at lower concentrations. Light controlled bacteriochlorphyll contents of R. rubrum and Rps. sphaeroides in a sigmoidal fashion. When growing at a constant low oxygen concentration cell protein formation increased with light energy flux in Rps. sphaeroides but remained unaffected in R. rubrum. Protein formation of R. rubrum increased with light energy flux only under anaerobic conditions. Two factor analyses were performed with R. rubrum and Rps. sphaeroides to study the combined effects of light and oxygen on bacteriochlorophyll formation. The results showed that both factors act independent of each other.Abbreviations ALA 5-aminolevulinic acid - R Rhodospirillum - Rsp. Rhodopseudomonas     

Isolation and Characterization of the Thylakoid Membranes from the NaCl-Resistant (NaClr) Mutant Strain of the Cyanobacterium Anabaena variabilis

NaCl-induced changes in the thylakoid membrane of wild-type Anabaena variabilis and its NaCl^r mutant strain have been studied. Biochemical characterization of the thylakoid membrane was done by taking its absorption and fluorescence spectra at different wavelength. The thylakoid membranes of both strains were isolated by mechanical disruption of the freeze-dried and lysozyme-treated cells, followed by differential and density gradient centrifugation. The light absorption spectra of the thylakoid membrane showed three and two peaks in NaCl^r mutant strain and its wild-type counterpart respectively at wavelengths of 400–850 nm. These peaks revealed that the thylakoid membrane contains a large amount of carotenoid and chlorophyll a. Fluorescence emission spectra of thylakoid membrane of NaCl^r mutant and its wild-type strain at excitation wavelength of 335 nm showed two different peaks, one at 340 nm and the other at 663 nm respectively. The light absorption and fluorescence spectra of the thylakoid membrane also revealed that the membrane contained carotenoid pigment, chlorophyll (Chl) a, and a pigment with an emission peak at 335 nm. The HPLC analysis of the pigments of the thylakoid membrane indicates that the NaCl^r mutant strain under NaCl stress contained an additional peak for the carotenoid pigment, which was lacking in its wild-type counterpart. The major peak in thylakoid membrane was that of echinenone and β-carotene. Whereas the polypeptide composition of thylakoid membrane differed in the wild-type and its NaCl^r mutant strain, no difference in the cell wall protein pattern was observed in both strains. The thylakoid membrane of NaCl^r mutant strain contained two additional protein bands that were absent in its wild-type counterpart. The thylakoid membrane of the wild-type and its NaCl^r mutant strain also showed morphological variations under NaCl stress. Received: 14 April 2000 / Accepted: 23 May 2000     

Early formation of intracytoplasmic membranes in Rhodospirillum rubrum

Cytoplasmic and intracytoplasmic membranes were isolated from Rhodospirillum rubrum by equilibrium sucrose density gradient centrifugation. Immediately after the induction of photosynthetically active intracytoplasmic membranes, bacteriochlorophyll is incorporated predominantly into the cytoplasmic membrane. With increasing pigment concentrations the newly arising intracytoplasmic membranes become sites of preferential bacteriochlorophyll incorporation. During this process the infrared absorption band of the pigment shows a red shift. The shift is more pronounced with intracytoplasmic than with cytoplasmic membranes. Pulse-chase of cytoplasmic membrane proteins reveals that such proteins become constituents of intracytoplasmic membranes.     

Functions of carotenoids in xanthorhodopsin and archaerhodopsin, from action spectra of photoinhibition of cell respiration

The recent discovery of a carotenoid light-harvesting antenna in xanthorhodopsin, a retinal-based proton pump in Salinibacter ruber, made use of photoinhibition of respiration in whole cells to obtain action spectra [Balashov et al. Science 309, (2005) 2061-2064]. Here we provide further details of this phenomenon, and compare action spectra in three different systems where carotenoids have different functions or efficiencies of light-harvesting. The kinetics of light-induced inhibition of respiration in Salinibacter ruber was determined with single short flashes, and the photochemical cross section of the photoreaction was estimated. These measurements confirm that the xanthorhodopsin complex includes no more than a few, and most likely only one, carotenoid molecule, which is far less than the core complex antenna of photosynthetic bacteria. Although the total cross-section of light absorption in the purple bacterium Rhodospirillum rubrum greatly exceeds that in Salinibacter, the cross-sections are roughly equivalent in the shared wavelength range. We show further that despite interaction of bacterioruberin with archaerhodopsin, another retinal-based proton pump, there is no significant energy transfer from this carotenoid. This emphasizes the uniqueness of the salinixanthin-retinal interaction in xanthorhodopsin, and indicates that bacterioruberin in Halorubrum species has a structural or photoprotective rather than energetic role.     

Comparative study of reaction centers from purple photosynthetic bacteria: Isolation and optical spectroscopy

Reaction centers from two species of purple bacteria, Rhodospirillum rubrum and Rhodospirillum centenum, have been characterized and compared to reaction centers from Rhodobacter sphaeroides and Rhodobacter capsulatus. The reaction centers purified from these four species can be divided into two classes according to the spectral characteristics of the primary donor. Reaction centers from one class have a donor optical band at a longer wavelength, 865 nm compared to 850 nm, and an optical absorption band associated with the oxidized donor at 1250 nm that has a larger oscillator strength than reaction centers from the second class. Under normal buffering conditions, reaction centers isolated from Rb. sphaeroides and Rs. rubrum exhibit characteristics of the first class while those from Rb. capsulatus and Rs. centenum exhibit characteristics of the second class. However, the reaction centers can be converted between the two groups by the addition of charged detergents. Thus, the observed spectral differences are not due to intrinsic differences between reaction centers but represent changes in the electronic structure of the donor due to interactions with the detergents as has been confirmed by recent ENDOR measurements (Rautter J, Lendzian F, Lubitz W, Wang S and Allen JP (1994) Biochemistry 33: 12077–12084). The oxidation midpoint potential for the donor has values of 445 mV, 475 mV, 480 mV and 495 mV for Rs. rubrum, Rs. centenum, Rb. capsulatus, and Rb. sphaeroides, respectively. Despite this range of values for the midpoint potential, the decay rates of the stimulated emission are all fast with values of 4.1 ps, 4.5 ps. 5.5 ps and 6.1 ps for quinone-reduced RCs from Rs. rubrum, Rb. capsulatus, Rs. centenum, and Rb. sphaeroides, respectively. The general spectral features of the initial charge separated state are essentially the same for the four species, except for differences in the wavelengths of the absorption changes due to the different donor band positions. The pH dependence of the charge recombination rates from the primary and secondary quinones differ for reaction centers from the four species indicating different interactions between the quinones and ionizable residues. A different mechanism for charge recombination from the secondary quinone, that probably is direct recombination, is proposed for RCs from Rs. centenum.Abbreviations RC reaction center - P bacteriochlorophyll dimer - H bacteriopheophytin - Q quinone - Rb Rhodobacter - Rs Rhodospirillum - Rps Rhodopseudomonas - EDTA (ethylenediamine)tetraaceticacid - LDAO N,N-dimethyl-dodecylamine-N-oxide - CTAB cetyltrimethylammonium bromide - DOC deoxycholate - Tris Tris-(hydroxymethyl)aminomethane - ns nanosecond - ps picosecond - fs femtosecond     

Lipids and Lipoprotein Complex in Photosynthetic Tissues

Lipids and pigments of photosynthetic bacteria, Rhodospirillum rubrum and Rhodopseudomonas capsulatus were examined. Common and prominent lipids in both bacteria were phosphatidyl ethanolamine and phosphatidyl glycerol. Rhodospirillum rubrum contained a special lipid containing ornithine. Their component fatty acids were straight chain saturated and monoenoic acids. No glycolipids were found in both bacteria. Ubiquinone-50 was detected in large amounts in both bacteria, and a new quinone and rhodoquinone were found in Rhodospirillum rubrum. The major carotenoids were spirilloxanthin, lycopene, and probably rhodopin. The results were compared with those of spinach and Anacystis, and discussed.     

Addition of new serogroups and improvement of the antigenic designs ofYersinia pseudotuberculosis

Eight strains ofYersinia pseudotuberculosis, untypable for any established serogroups, were studied. They were isolated from humans (three), dogs (two), cat (one), and rats (two), and the general characteristics of the strains were identical with those ofY. pseudotuberculosis. On the basis of results of O-agglutinin absorption tests, these strains were classified into three new serogroups. The new serogroups proposed were serogroups IIC, VII, and VIII, and a new O-antigenic scheme ofY. pseudotuberculosis was designed.     

The lipopolysaccharides of Rhodospirillum rubrum,Rhodospirillum molischianum,and Rhodopila globiformis

The cell wall lipopolysaccharides from three phototrophic species of the alpha₁-group of Proteobacteria, Rhodospirillum rubrum, Rhodospirillum molischianum, and Rhodopila globiformis were isolated and chemically characterized. Sodium deoxycholate polyacrylamide gel electrophoresis patterns revealed that the lipopolysaccharides of all three species possess O-chains. They are composed of repeating units only in R. molischianum and R. globiformis. The presence of l-glycero-d-mannoheptose and 2-keto-3-deoxyoctonate indicated core structures in all three lipopolysaccharides. Glucosamine was found as backbone amino sugar in lipid A of R. molischianum and R. rubrum, while R. globiformis has 2,3-diaminoglucose as backbone amino sugar. The latter species also differed from the two former ones in its content of hydroxy fatty acids (3-OH-14:0, 3-OH-16:0 in R. rubrum and R. molischianum and 3-OH-14:0, 3-OH-18:0 and 3-OH-19:0 (possibly iso- or anteisobranched) in R. globiformis).Abbreviations DOC-PAGE sodium deoxycholate polyacrylamide gel electrophoresis - GC/MS combined gas-liquid chromatography/mass spectrometry - KDO 2-keto-3-deoxyoctonate