Ducellieria chodati — Alge oder Pilz?

Ducellieria chodati Teiling is an organism rarely mentioned from plankton samples. Its propagation was unknown, and all earlier authors have failed to see that it is a colourless organism. Because of its structure and some chemical reactions,Ducellieria was thought to be a member of theXanthophyceae. Many living coenobia ofD. chodati from several Austrian lakes and some steps of their reproduction have been studied: Zoospores with two unequal flagella are released. After a mobile phase they settle on coniferous pollen grains drifting in water. Inside the pollen grain, a tube or flask is developed from which zoospores are released again after one or two days. These aggregate to form newDucellieria coenobia. These observations suggest thatDucellieria chodati belongs to thePhycomycetes, perhaps to theSaprolegniales.

     

D-Amino acids of the amino acid pool and occurrence of racemase andD-amino acid oxidase activities inEscherichia coli B

Less than 20 % of the amino acid content of the amino acid pool ofEscherichia coli B exists in theD-form. Alanine, glutamic acid, and valine were shown by gas-chromatography to be partially in theD-form. OnlyD-alanine was formed by racemization in the crude extract of this organism. Alanine racemase was easily released from the membranes or vesicles butD-alanine oxidase activity remained firmly bound to the membrane. Most protein amino acids stimulated proline uptake into the vesicles, and the oxidative deamination activities were verified by the proline uptake stimulating amino acids. It is concluded that the obligatory pathway of L-amino acid -D-amino acid - oxo acid which exists in the oxidation ofL-alanine does not exist with otherL-amino acids. It is likely that otherD-amino acids in the pool are formed in the presence ofD-amino acid oxidase orD-amino acid aminotransferase.     

Floral anatomy and systematic position ofVivianiaceae

The floral anatomy of four species ofViviania has been studied. In the basic floral plan and essential floral anatomical featuresViviana closely resembles theGeraniaceae. Evidence from vegetative and floral anatomy, ultrastructural studies on phloem as well as phytochemistry supports geranialean affinity ofViviania; the placement within thePittosporales sensuHutchinson being unnatural.     

Evolution and systematic relationships in theTriticeae (Poaceae)

The evolution and taxonomic relationships in theTriticeae are discussed with the view to highlight aspects of this agronomically important group of plants, which may be of interest to molecular biology. Some of these aspects are addressed in more detail in adjoining papers in which specific genomic loci have been examined at the DNA sequence or isozyme level. Aspects discussed include the systematics and geographic distribution of theTriticeae species, isozyme and chromosome pairing studies on some of the species as well as more recent developments in DNA analyses. A survey of the systematics of theTriticeae indicated that the genomic system ofLöve is probably the most useful starting point for interpreting molecular data even though the system has many problems from a taxonomic point of view. The geographical distribution ofTriticeae species, using both published and unpublished data, suggested that information of this type taken together with the theory of continental drift provides a broad time-span for considering data from DNA sequence studies. The significance, and modes of analyses, of isozyme studies were assessed because they often provide valuable characters in determining relationships between species. The main character underlyingLöve's andDewey's analyses of theTriticeae, namely chromosome pairing, is discussed with particular reference to isozyme studies to show that in some cases, such as species ofHordeum sensu lato, consistent relationships are obtained. Finally, new developments in understanding chromosome structure are considered in relation to the above variables in the taxonomy and evolution of theTriticeae.     

Relationships ofJusticieae (Acanthaceae) based on cytology

The eytology of some species representing the subtribesBarlerieas, Andrographideae, Eujusticieae andDicliptereae of theJusticieae ofBentham & Hooker, suggests thatBarlerieae are the most primitive subtribe. Separation ofBarlerieae in Engler's system from the tribeJusticieae has been supported. But separation ofEcbolium andRungia in a different taxon,Odontonemeae in the classification ofEngler does not find justification. The position ofRungia underDicliptereae (Bentham & Hooker) is supported.     

Taxonomy and phylogeny of the tribePlucheeae (Asteraceae)

The tribePlucheeae (Benth.)A. Anderb., has been analysed cladistically by means of a computerized parsimony program (Hennig 86), using theArctotideae as outgroup. The results of the analysis are presented in a consensus tree and one cladogram. Four major monophyletic subgroups can be recognized: TheColeocoma group (3 genera), thePterocaulon group (3 genera), theLaggera group (6 genera), and thePluchea group (12 genera). All recognized genera are described and most genera are supplied with taxonomical notes including comments on their taxonomic status. Genera such asBlumea, Pluchea, andEpaltes are demonstrated to be unnatural assemblages.Monarrhenus andTessaria are both closely related to thePluchea complex. The old generic nameLitogyne Harv. has been taken up for one species ofEpaltes, the genusRhodogeron is reduced to a synonym ofSachsia, and the following new combinations are made;Litogyne gariepina (DC.)A. Anderb., andSachsia coronopifolia (Griseb.)A. Anderb.     

The determination of micro-organisms in air

Summary A brief discussion has been given of various devices available for the determination of micro-organisms in air. In order to investigate the efficiency of some of these devices it proved desirable to work with artificially contaminated air. Hereto clouds of spores ofBacillus cereus were produced with the aid of a modified model of aDe Vilbiss 40 nebulizer.Comparative tests were made with theFolin-bubbler, theWheeler-bubbler, theMoulton-atomizer and the capillary impinger as used byRosebury for the determination of the spore concentration in the contaminated air. The latter device proved to be by far the most efficient, 99% or more of the spores being retained by this simple apparatus.     

Heterogeneity in oligosaccharides from theO-polysaccharide chain of the lipopolysaccharide fromSalmonella typhi 253Ty determined by fast atom bombardment mass spectrometry

Oligosaccharides from theO-polysaccharide chain of theSalmonella typhi 253Ty lipopolysaccharide (LPS) were prepared from delipidated LPS by digestion with bacteriophage P22. The oligosaccharides were separated by gel chromatography into fractions representing monomers to polymers of the basic tetrasaccharide repeating unit. Fractions containing the dimer and the trimer were analysed by fast atom bombardment-mass spectrometry as methylated alditols. The mass spectra clearly showed heterogeneity in terms ofd-glucose substitution of thed-galactose residue in the tetrasaccharide repeating unit: dimers with none, one, or twod-glucosyl branches and trimers with none, one, two, or threed-glucosyl branches were found. This suggests a randomd-glucosylation of theO-polysaccharide chain ofS. typhi 253Ty.     

Serial reconstruction of the mitochondrial reticulum in the antarctic flagellate,Pyramimonas gelidicola (Prasinophyceae,Chlorophyta)

Summary A serial reconstruction ofPyramimonas gelidicola McFadden, Moestrup andWetherbee has revealed a large reticulated mitochondrion branching throughout the cell. The possibility of single mitochondria in other members of thePrasinophyceae and the uniformity of the morphology of this organelle within the class is discussed.     

Metabolic design in the amino-acid-producing bacteriumCorynebacterium glutamicum

The Gram-positive bacteriumCorynebacterium glutamicum is used for the industrial production of amino acids,e.g. ofl-glutamate andl-lysine. By cloning and expressing the various genes of thel-lysine pathway inC. glutamicum we could demonstrate that an increase of the flux ofl-4-aspartaldehydate tol-lysine could be obtained in strains with increased dihydro-dipicolinate synthase activity. Recently we detected that inC. glutamicum two pathways exist for the synthesis ofdl-2,6-diaminopimelate andl-lysine. Mutants defective in one pathway are still able to synthesize enoughl-lysine for growth but thel-lysine secretion is reduced to 50–70%. Using NMR-spectroscopy we could calculate how much of thel-lysine secreted into the medium is synthesizedvia the one and the other pathway. Amplification of the feedback-inhibition-insensitive-homoserine dehydrogenase and homoserine kinase in a highl-lysine-overproducing strain made it possible to channell of the carbon flow from the intermediate 4-aspartaldehydate toward homoserine, resulting in a high accumulation ofl-threonine. For a further flux froml-threonine tol-isoleucine the allosteric control of threonine dehydratase was eliminated. Dedicated to Dr. Z. Vaněk on the occasion of his 70th birthday Presented at theIUMS Congresses '94-7th International Congress of Bacteriology and Applied Microbiology Division, Prague, July 3–8, 1994 (Bacteriological Symposium BS-12Regulation of Microbial Product Overproduction).     

Relationships in theAcanthaceae and related families as suggested by cladistic analysis ofrbcL nucleotide sequences

A parsimony analysis of DNA sequences of the chloroplast-encoded generbcL from twelve members of theAcanthaceae s.l., including members of the sometimes segregateThunbergioideae andNelsonioideae, and other families in theBignoniales sensuThorne (1992) is presented. The results largely agree with the classification of theAcanthaceae presented byBremekamp (1965) andThorne (1992) and supportNelsonioideae as a sister group to the rest of theAcanthaceae. Thunbergioideae are placed as a sister toAcanthaceae s.str.Acanthus andAphelandra, both representatives ofAcanthoideae, form a sister group toRuellioideae. An analysis of branch support found that many branches throughout theBignoniales are weakly upheld. This points to the need for further studies in the group using more sequences ofrbcL as well as other data. None of the families ofBignoniales as presently circumscribed (includingAcanthaceae s.l.) were strongly supported, although the larger clade containing the families of theBignoniales was robust.     

Properties of the hydantoinase from agrobacterium SP. IP I-671

Summary A hydantoin-hydrolyzing enzyme has been purified from an newly isolatedAgrobacterium sp. by procedures including ammonium sulfate fractionation and ion-exchange chromatography. Kinetic studies have demonstrated that this enzyme, which is strictlyd-selective and has a broad substrate specificity exhibits remarkable stability. Microbial bioconversion at 60°C and pH 10.0, allowed complete conversion of 30 g/L ofd,l 5-benzylhydantoin into thed N-carbamyl derivative of phenylalanine (molar yield of 96%) in less than 10 h. The hydantoinase is activated by Ni²⁺ ions.     

Asolcus bennisi n. sp. (Hymenoptera,Proctotrupoidea) parasite oophage deGraphosoma lineata L. (Het. Pentatomidae)

Summary The Author describes from Morocco a new species ofAsolcus which is closely related to the sibling speciesA. basalis Wollaston andA. nigribasalis Voegelé. The species is namedA. bennisi and parasitizes in nature the eggs ofGraphosoma lineata L. The separation ofA. bennisi from the species of thebasalis group is based on biological tests and on a characteristic pigmentation of the parasitized host eggs reared under optimal laboratory conditions.      

Characterization and phylogenetic distribution of a chloroplast DNA rearrangement in theBerberidaceae

Restriction site maps and a clone bank of chloroplast DNA (cpDNA) ofMahonia higginsae (Munz)Ahrendt (Berberidaceae) were constructed. The size ofMahonia cpDNA was about 167 kb. Precise mapping using gene probes revealed that cpDNA ofM. higginsae has an inverted repeat (IR) 11.5 kb larger than the tobacco IR. The expansion of the IR into the large single copy region has resulted in the duplication of at least ten genes includingpsbB. The phylogenetic distribution of the expanded IR was examined in twenty-five species ofBerberis andMahonia, twenty species representing the fifteen remaining genera of theBerberidaceae, and four species from four allied families. Our survey indicates that only the species of the closely related generaBerberis andMahonia share the 11.5kb expansion of IR. This result supports their close phylogenetic relationship, which has been suggested previously by chromosomal, morphological, and serological data.     

Die Stipeln derIrvingioideae undRecchioideae und ihre systematische Wertung nebst Bemerkungen zur Holzanatomie und Palynologie

TheSimaroubaceae generally have no true stipules. The stipule-like appendages of some genera proved to be pseudo- or metastipules (Weberling & Leenhouts 1965). There seem to be some exceptions, however: the generaCadellia (incl.Guilfoylia) andRecchia on the one hand, and theIrvingioideae on the other. As these taxa, with exception ofRecchia, have simple leaves, there are no indications that their stipule-like appendages might be pseudo- or metastipules. In regard to their position and ontogeny these appendages behave completely like true stipules. Assuming the view ofForman, one could conceive a morphological line from the long, broadly inserted axillary stipules of mostIrvingioideae to the small scaly triangular stipules ofIxonanthoideae. The similarities between the stipules ofIrvingioideae andErythroxylaceae (already emphasized byHallier and others), become even more evident when their ontogeny is investigated. TheIrvingioideae, therefore, might be regarded as a separate family (perhaps with some relation to theErythroxylaceae,Hallier) or as a subfamily ofIxonanthaceae (Forman).—In addition to data on stipules some results on the palynology and shoot anatomy of the generaCadellia (incl.Guilfoylia) andRecchia are reported. Their relationship with theSimaroubaceae also appears doubtful. If they are to be included, they represent a somewhat isolated group near the base of the family which otherwise has lost its stipules.

Herrn Univ.-Prof. Dr.Walter Leinfellner zum 70. Geburtstag gewidmet.     

Deacetylation ofN-acetylthienamycin to thienamycin by a cell-free extract ofStreptomyces cattleya,the thienamycin producer

Summary A cell-free extract from the thienamycin producer,Streptomyces cattleya, has been found to deacetylate the co-product,N-acetylthienamycin. The pH optimum of the reaction is 7.5. Due to the lability ofN-acetylthienamycin, we used thed andl forms of the synthetic substrateN-chloroacetylvaline. We found that the enzyme is anl-deacetylase, has a molecular weight of 58 000, is stable up to 40°C, acts optimally at 45°C, is stable at pH 5–8, is not activated by divalent metal ions and is inhibited by Hg⁺⁺, Cu⁺⁺ andp-chloromercuribenzoate. This is the first report of an extract from a carbapenem producer which carries out the deacetylation ofN-acetylthienamycin, suggesting that the acetylated derivative is a precursor of thienamycin.Abbreviations THM thienamycin - N-AcTHM N-acetylthienamycin - CFE cell-free extract - N-Cl-Ac-l-Val N-chloroacetyl-l-valine - N-Cl-Ac-d-Val N-chloroacetyl-d-valine     

The taxonomic status ofToxoplasma gondii

Summary The taxonomic status ofToxoplasma gondii is reviewed. Two electron photographs are figured, in which up to now non described structures are visible: 1. at the anterior end a conus, which is not identical with the conoid ofGustafson, Agar andCramer; 2. the invagination of this conoid into the anterior pole (conus). Arguments are mentioned speaking for the possibility of a relationship ofToxoplasma with theGregarines. So long as no more arguments are put forward, it deserves recommendation to classifyToxoplasma with unclassifiedSporozoa.     

Pollen morphology ofLactoridaceae

The pollen wall ultrastructure of the primitive AngiospermLactoris fernandeziana Phil. (Lactoridaceae) is described. The monosulcate aperture, granular wall structure and sacci (all primitive features) suggest placement of this family in theMagnoliales. Pollen ofLactoris is compared to fossil dispersed pollen from the Lower and lower-Upper Cretaceous. The fossil pollen shares characteristics which are restricted to theLactoridaceae suggesting that this family was present during the early Cretaceous.     

Hectorella: A member of the betalain-suborderChenopodiineae of the orderCentrospermae

Roots ofHectorella caespitosa Hook. f. were induced to produce a red pigment which was shown to be a betalain and not an anthocyanin. These data indicate thatHectorella belongs to theChenopodiineae, the betalain suborder of theCentrospermae, and excludes alignment with the anthocyanin family theCaryophyllaceae.     

Mini-transposon Tn5gfp constructs for differential tagging of microorganisms

Recently thegfp (green fluorescent protein) gene from the jellyfishAequoria victoria has been widely used as a reporter gene. In this study mini-transposons, named as mini-Tn5gfp, were constructed by subcloning thegfp gene into a transposon Tn5. To improve the expression level of thegfp gene, tandom array ofgfp gene was obtained. The constructs were successfully used in tagging target microorganisms by transposition. The level of GFP expression was found to be closely correlated with the copy number of the gfp transposed. These constructs will facillitate not only efficient tagging of whole organism but also genetic marking of target genes by transposition.