bluuebunny/crossref_metadata_2025_split huggingface dataset:
High level expression of heterologous proteins in methylotrophic yeast Pichia pastoris
Authors: Sreekrishna K. , Potenz Rica H. B. , Cruze John A. , McCombie William R. , Parker Kathryn A. , Nelles Lynn , Mazzaferro Paul K. , Holden Kathy A. , Harrison Roger G. , Wood Phyllis J. , Phelps Doris A. , Hubbard Cindi E. , Fuke Motohiro 
Published: February 2007

AbstractExpression of human tumor necrosis factor —α (TNF) and four different TNF analogs has been studied in Pichia pastoris by utilizing the alcohol oxidase gene promoter. TNF expression level in certain transformants accounted for as much as 36% of the soluble protein. TNF expression was stably maintained during high cell density fermentation (100 g dry cell weight/liter) resulting in a TNF production level of 6–10g/liter. TNF contained in P. pastoris cell lysates was biologically active as determined by its cytotoxic effect on murine L‐929 fibroblast cells and the bioactivity was retained for at least 6 months in the lysates stored frozen at −20 °C in the presence of protease inhibitor PMSF. TNF expressed in P. pastoris was recognized by monoclonal antibodies prepared against recombinant Escherichia coli derived TNF. TNF purified from P. pastoris has the expected N‐terminal amino acid sequence and specific activity of 107 units/mg protein. TNF analogs were also expressed at levels comparable to that of native TNF. Three of the four analogs were insoluble when produced in P. pastoris.
Taxonomic studies of Acinetobacter species based on the electrophoretic analysis of enzymes
Authors: Nishimura Yukimasa , Kanzaki Hisanaga , Iizuka Hiroshi 
Published: February 2007

AbstractThirty six strains of Acinetobacter, 22 strains from the culture collections and 14 isolates from soil and cotton samples, were examined for the presence of twelve enzymes using polyacrylamide gel electrophoresis. A numerical analysis was carried out on the basis of similarity values obtained from the electrophoretic mobilities of the enzymes. The strains used were divided into four clusters (Z‐1, Z‐2, Z‐3 and Z‐4), and cluster Z‐1 was further divided into three subclusters (Z‐1a, Z‐1b and Z‐1c). The type strains of Acinetobacter calcoaceticus IAM 12087 (ATCC 23055) and Acinetobacter Iwoffii ATCC 15309 were found to belong to subcluster Z‐1a and cluster Z‐4, respectively. The radiation‐resistant strain FO‐1, a new type of acinetobacters, was included in cluster Z‐3. Superoxide dismutase showed clearly distinguishable mobilities among four clusters, and was concluded to be useful in grouping acinetobacters.
Partial characterization of α‐mannosidase from Yarrowia lipolytica
Authors: Vega Rosario , Domínguez Angel 
Published: February 2007

AbstractAn exo‐α‐mannosidase (E.C. 3.2.1.24) was characterized in the yeast form of Yarrowia lipolytica. The enzyme located in a crude particulate fraction of the cell extract is under catabolite repression, has an optimum pH of 6.0, a Km of 0.27 mM with p‐nitrophenyl‐α‐D‐mannopyranoside and is partially inhibited by D‐mannose.The enzyme is not affected by ethylenediaminotetraacetic acid, several cations (only Zn++ increased its activity in a 25%) or sulphydryl reagents and can be partially solubilized by treatment with digitonine.
Survey of the pSM10 family of streptococcal cloning vectors
Authors: Laplace Frank , Klessen Christian , Malke Horst 
Published: February 2007

AbstractA survey of the pSM10 family of streptococcal plasmid cloning vectors is provided. These vectors are derived from a macrolide‐lincosamide‐streptogramin B resistance plasmid and include general cloning vectors, shuttle vectors, helper plasmids, expression vectors, gene fusion vectors and phasmids. Besides describing their general properties, this paper also provides their genetic and physical maps.
Amplification of different ColEl plasmids in an Escherichia coli relA strain
Authors: Schroeter A. , Riethdorf S. , Hecker M. 
Published: February 2007

AbstractAmino acid starved cells of an E. coli relA strain accumulate a large amount of pBR322 plasmid DNA. In this study ColEl related plasmids of different copy number and size including a high copy number plasmid mutant of pBR322 were amplified in a relA strain of E. coli K‐12 under amino acid limitation in order to determine the upper plasmid level in amino acid starved cells. In all cases we measured a 4 to 6 fold increase of the plasmid copy number in comparison to log‐phase cells independent of the size, the number of origins per plasmid molecule or the copy number in log‐phase cells. The plasmid copy number in amino acid starved cells varies from about 200 (pBR322‐dimer) to about 2000 (high copy number plasmid pERIII‐BPL4, see BOROS et al. 1986). Rop+ and rop− plasmids show the same amplification rate under the used conditions.
Effect of soil treatment with sewage and sludge on fungal populations
Authors: Abdel‐Mallek A. Y. , Moharram A. M. , Bagy M. M. K. 
Published: February 2007

AbstractThe effect of soil treatment with sewage and sludge at three doses (1%, 10% and 20% w/w) on its fungal population was studied in vitro. The treatment of soil with sewage significantly increased the count of total fungi after 1 week by the high dose, and after 12 weeks by each of the three doses. Fungi differed in their response to the different doses of sewage: some were promoted and others were inhibited. The count of total fungi was significantly raised by the low dose of sludge after 1 week of soil treatment, and by the medium and the high doses after 12 weeks. Counts of all fungi were significantly increased at certain treatments with sludge, except those of Aspergillus niger (at the high dose after 6 weeks), Fusarium (at each of the three doses after 3 weeks and at the high dose after 6 weeks) and Paecilomyces varioti (by the medium and the high doses after 1 week) whose counts were significantly lower than those in untreated soil.
Ultrastructural characteristics of Claviceps purpurea seed cultures
Authors: Didek‐Brumec Matjana , Jezernik Kristijan , Puc Anka , Sočič Helena 
Published: February 2007

AbstractUltrastructural characteristics of optimally developed seed cultures of two morphologically and biochemically different Claviceps purpurea strains were established. The vegetative mycelium of both conidial (L‐17) and mycelial (L‐18) strains was filamentous and consisted of cells with a polynuclear state. Differences between the strains were more expressed in the ultrastructure of the cytoplasm which contained different and numerically more organelles in the strain L‐17 in comparison with the strain L‐18. This conidial strain developed from a parasitic strain retained in submerged seed cultures the ultrastructural characteristics of sphacelia. Seed cultures of both strains were also characterized by large mitochondria with the dense matrix and numerous cristae, which usually did not appeared before the alkaloid production.
Crystalline structures within vacuoles of n‐alkane‐grown Mucor circinelloides: Cytochemical evidence of NAD(P)H oxidase activity
Authors: Fischer W. , Ude J. 
Published: February 2007

AbstractCrystalline structures of the fungus Mucor circinelloides were investigated substructurally and cytochemically by means of electron microscopy. The crystals, preferably localized within vacuoles and vesicles, are abundant in hyphae grown on n‐alkanes or 1‐decanol. Stripes and spot patterns with different dispositions are evident in the planes of sectioned crystals. Membraneous structures are in close spatial relation to crystalline inclusions.The crystals reveal NAD(P)H oxidase activity, as demonstrated by the cerium precipitation technique. The amount of reaction product as well as the quantity of reactive inclusions both depend on the carbon source of the nutrient medium. It was demonstrated that the formation of reaction product is insensitive to 1 mM KCN; it depends rather on both NADH and NADPH, with NADPH being the most efficient substrate, p‐chloromercuribenzoate in the incubation medium results in a drastic reduction in the amount of deposited precipitate; this indicates that the observed cerium precipitation is attributed to enzyme activity. Catalase activity was found to be restricted to microbodies.The accumulation of the reactive, crystalline condensed material on hydrocarbon‐grown hyphae might account for a changed cellular metabolism.
Candida mucifera n. sp.
Authors: Kocková‐Kratochvílová Anna , Sláviková Elena 
Published: February 2007

AbstractA new yeast, Candida mucifera, isolated from livers of anurans in the forest of Amazonia, is described. This species differs from all recently accepted Candida species in its morphological and physiological properties and in the fact that in sugar liquid media it produces a large quantity of extracellular polysaccharide that is of a gelatinous consistency.
Degradation of 3‐aminophenol by Arthrobacter spec. mA3
Authors: Lechner U. , Straube G. 
Published: February 2007

AbstractThe bacterial strain mA3 capable of utilizing 3‐aminophenol as the sole source of carbon, energy and nitrogen for growth was isolated from an enrichment culture and identified as an Arthrobacter species. Utilization of 0.68 mg ml 3‐aminophenol by batch cultures of this organism was characterized by a specific growth rate (μ) of 0.18 h−1 and a yield coefficient (Y) of 0.60. In chemostat cultures of strain mA3 we determined a critical dilution rate (Dc) of 0.175 h−1 by continuous addition of mineral salt medium with 0.5 mg/ml 3‐aminophenol.Evidence was obtained that the degradation of catechol by 3‐aminophenol induced as well as non‐induced cells follows the β‐ketoadipate pathway. The excess ammonium ions, originating from 3‐aminophenol degradation and not needed for assimilation were released into the medium. Cells adapted to 3‐aminophenol exhibited a high substrate specificity. Among different aromatic substances tested, only catechol and 3,4‐dihydroxybenzoate could serve as a carbon source for growth. The importance of the meta position of the amino group for the first step of hydroxylation is discussed in connection with the substrate specificity of whole mA3 cells.
Microscopic structure of ineffective alfalfa nodules formed by auxotrophic mutants of Rhizobium meliloti
Authors: Małek Wanda 
Published: February 2007

AbstractThe inoculation of lucerne seedlings with mutants of Rhizobium meliloti (Arg−) requiring arginine resulted in the formation of ineffective nodules. In these nodules bacteria were not released from the infection threads into the nodule cytoplasm. When arginine was provided as a nitrogen source, the nodules became anatomically similar to those induced by the wild type strain and they fixed nitrogen. Effective nodules were induced also by prototrophic forms of revertants and transductants.The infected cells in the central tissue of the effective nodule were enlarged, whereas uninfected ones of noneffective nodules of Arg− mutants remained small and contained small nuclei and many large starch granules.
Improvement of medium composition by random balance designs
Authors: Recknagel R.‐D. , Bormann E.‐J. , Friedrich W. 
Published: February 2007

AbstractIf the number of potentially relevant compounds which have to be optimally selected is large, then random balance experimentation provides a useful tool for the development of nutrient media.The object of investigation was a thiostrepton producing Streptomyces strain from our own collection. The thiostreptone formation was increased although we had insufficient information about the physiological needs or regulation aspects concerning the biosynthesis. The medium development was carried out alongside mutation experiments within a limited temporal interval.Our study shows how a 9‐component medium can be improved by a 6‐point experimental design. At the end of the paper the basic principles for constructing restricted random balance designs are outlined.
Nachweis einer direkten Isomerisierung von Mannose zu Fructose und ihre Bedeutung für den Mannosestoffwechsel von Pseudomonas syringae pv. phaseolicola
Authors: Sauerstein J. , Ramm M. , Schubert K. , Reuter G. 
Published: February 2007

AbstractThe phytopathogenic pseudomonad Pseudomonas syringae pv. phaseolicola possesses an isomerase which converts mannose to fructose. The synthesis of this enzyme is constitutive. The KM value for mannose is 0.02 M. Fe2 +, Mg2 + and Mn2 + ions stimulate the enzyme activity, whereas Cu2 + and Zn2 + iones are inhibitors. Since the enzymes mannokinase and phosphomannose isomerase could not be detected, the isomerase and an inducible fructokinase must have a function in the metabolism of mannose by this bacterium.
Methodische Untersuchungen zur Interferon‐Induktion unter in vitro‐Bedingungen
Authors: Glück Brigitte , Stelzner Axel 
Published: February 2007

AbstractThe procedures generally used for the in vitro induction of interferon exploit fibroblast or leucocyte culture suspensions. Several factors and conditions influencing the capacity for IFN induction were studied, with the following results.In contrast to previous findings, optimum IFN induction was obtained at 37 °C, rather than 30 °C, when human fibroblasts were induced with 100 μg/ml of Poly (IC). There was a direct correlation between the dose of the inducing agent applied and the amount of IFN produced. Also, the cells were excellently superinducible with metabolic inhibitors like actinomycin D and cycloheximine. In addition, priming procedures enhanced IFN induction in human fibroblasts.Comparing different cell types with respect to their ability to be induced for IFN production, we found that different cell types show great differences in their inducer sensitivity. Finally, the response of different cell culture systems was highly variable when induced with different compounds.
Production of extracellular enzymes during growth and autolysis of Pycnoporus cinnabarinus
Authors: Gomez‐Alarcon G. , Lahoz R. , Molina D. 
Published: February 2007

AbstractChanges in cultural parameters and the production of some extracellular enzymes during growth and autolysis of the white‐rot fugus Pycnoporus cinnabarinus have been studied. At the end of the autolytic period (52 days of incubation) the degree of autolysis was greater than 50%. The laccase activity reached its highest value during the growth period, when the level of the carbon source in the medium was still comparatively high. When the fungus was cultivated in the presence of kraft lignin (Indulin AT) 0.05% (w/v), the activity of laccase was 3 times higher than when grown in the absence of lignin. The presence of lignin did not affect the activities of 1,3‐β‐glucanase, exoxylanase and proteases.
An electron microscopic study of alterations in the morphology and permeability of purified Mycobacterium leprae
Authors: Prabhakaran K. , Job C. K. , Harris E. B. , McCormick G. T. 
Published: February 2007

AbstractThis communication reports the association of changes in ultrastructure of Mycobacterium leprae with alterations in its permeability. To study morphologic changes of the organisms under different conditions (of temperature and exposure to NaOH and trypsin), ultrathin sections of the bacteria were cut and examined in an electron microscope. In the untreated bacilli and those washed with trypsin, the cytoplasmic membrane and the cell wall (peptidoglycan layer) remained intact; dapsone showed little effect on diphenoloxidase of the bacteria. M. leprae is unique among mycobacteria in possessing an unusual form of the enzyme diphenoloxidase. The antileprosy drug dapsone is a potent inhibitor of the enzyme, but it does not readily penetrate the bacteria where the cell envelope remains intact. The cell wall of M. leprae exposed to −80 °C or washed with NaOH was partially detached from the cell membrane; dapsone readily penetrated these organisms and inhibited the bacterial enzyme. In the above preparations, the cytoplasmic membrane appeared undamaged and the bacteria remained viable, as evidenced by multiplication in mouse foot pads. At 50 °C, the peptidoglycan layer became completely separated from the membrane and the cytoplasm was partially denatured. These organisms were permeable to dapsone, but were no longer viable. At 100 °C, the structural organization of the bacilli was completely destroyed, and of course, they lost their enzyme activity as well as viability. Evidently, the intact cell wall layer mediates the exclusion of dapsone from M. leprae, and there is no correlation between its viability and permeability. The ultrathin sections also reveal the internal organization and cytoplasmic inclusions of M. leprae, as never before seen.
Beeinflussung der Phagocytose durch verschiedene Kl‐Kapselpräparationen von Escherichia coli
Authors: Sokolowska‐Köhler Wanda , Bollmann Renate , Mehl Michael , Starke Roland , Presber Wolfgang 
Published: February 2007

AbstractThe influence of two different types of Escherichia coli Kl capsule preparation on the phagosytosis of an E. coli laboratory strain (LN 28) by polymorphnuclear leucocytes (PMNL) is described.Capsule material of E. coli 0 18 and 0 83 was prepared a) from the culture supernatant and b) from a bacterial pellet fraction. When capsule material from the pellet was added to opsonin, before mixing the laboratory strain with the PMNL, it decreased the rate of phagocytosis, compared with untreated opsonin. The preparation from the supernatant of capsule showed no alteration of phagocytosic rate or capacity.These results are explained by the different chemical compositions of the preparations.
Functional half‐life of the alpha‐amylase mRNA of Bacillus licheniformis
Authors: Tonkova Alexandra , Pazlarová Jarmila , Emanuilova Elka , Stoeva Nelly 
Published: February 2007

AbstractSome aspects of the regulation of α‐amylase synthesis in Bacillus licheniformis CCM 2205 were investigated. The effect of actinomycin D and chloramphenicol was studied at the level of RNA transcription and translation, α‐amylase synthesis in Bacillus licheniformis CCM 2205 was practically not altered during the first 20 min after the addition of actinomycin D, although RNA synthesis was almost completely blocked. In contrast to RNA polymerase inhibitor, chloramphenicol stopped immediately the synthesis of α‐amylase. By using the least squares method the mean half‐life of α‐amylase mRNA was calculated to range from 7.5 to 8.4 min. The mean half‐life of cell protein mRNA was determined to range from 2.6 to 3.8 min. Having in mind the immediate effect of chloramphenicol on the α‐amylase synthesis, it can be concluded that de novo protein synthesis is required in the case of actinomycin D resistant residual synthesis.
Isolation and characterization of mutants of Trichosporon adeninovorans resistant to 2‐deoxy‐D‐glucose
Authors: Büttner R. , Scheit A. , Bode R. , Birnbaum D. 
Published: February 2007

AbstractWe isolated stable mutants from Trichosporon adeninovorans resistant to 2‐deoxy‐D‐glucose. All mutants were altered in the C‐catabolite repression and produced different amounts of glucoamylase and β‐glucosidase when grown on several carbon sources. In addition to the C‐catabolite derepression of these extracellular enzymes, a repression defect of isocitrate lyase was found.
Ultrastructure of Borrelia burgdorferi in tissues of patients with Lyme disease
Authors: Hulínská Dagmar , Jirouš Jan , Valešová Marika , Herzogová Jana 
Published: February 2007

AbstractSpirochetal organisms were sought in 18 skin and 4 synovial membrane specimens obtained by biopsy from 22 Lyme disease patients. The presence of spirochetes in body tissues was histologically demonstrated in one patient with lymphadenosis benigna cutis, one patient with acrodermatitis chronica atrophicans and in one patient with active arthritis. The organisms were 5–30 μm long and 0.12–0.25 μm thick, had 8 or 11 flagella arising from both ends of the body, and their ultrastructure was analogous to that of cultured Borrelia burgdorferi strains. They were located intra‐ or perivascularly, or in the collagenous connective tissue of the skin and synovium. This implies that Lyme spirochetes may have a potential to survive in body tissues and cause injury to blood vessels.
Stability and expression of the staphylococcal constitutive macrolide‐lincosamide‐streptogramin B resistance plasmid pE3692 in Staphylococcus aureus and Bacillus subtilis
Authors: Więckiewicz Jerzy , Wójcik Kinga 
Published: February 2007

AbstractThe constitutive MLS resistance plasmid pE3692 (2.4 kb) from S. aureus and pE3692‐9 plasmid derived from pE3692 by in vitro deletion of the small HindIII‐HindIII fragment Sta t (0.3 kb) were introduced into S. aureus RN450 and B. subtilis UOT0277 strains. The pE3692 plasmid was completly stable in S. aureus RN450, however, in B. subtilis UOT0277 this plasmid was segregationally unstable. Deletion of the Sta t fragment from the pE3692 reduced plasmid stability considerably both in S. aureus and B. subtilis host strains. The lower expression of tylosin‐resistance of the erm gene of the pE3692‐9 plasmid in B. subtilis UOT0277 strain was also observed.
Sexual behavior and its pheromonal regulation in ascosporogenous yeasts
Authors: Yoshida Kazuo , Hisatomi Taisuke , Yanagishima Naohiko 
Published: February 2007

AbstractWe reviewed our investigations on sexual behaviors and interactions including sexual cell agglutination and pheromone action mainly in non‐conventional yeasts, Hansenula anomala, H. wingei, Pichia amethionina, P. heedi, P. opuntiae, Saccharomyces kluyveri, S. globosus, S. exiguus, Saccharomycodes ludwigii. The techniques and genetic models including the cassette model and α1‐α2 hypothesis which had been developed largely in S. cerevisiae were applicable to these yeasts in principle. The sexual agglutination was distinctly species‐specific while sex pheromones were cross‐reactive beyond species' barriers. The successful induction of heterothallic strains from homothallic strains in S. exiguus by mutagenesis enabled to the subsequent biochemical and genetical analysis of sexual behavior in the yeast. The phylogenetic consideration on sex differentiation is also included.
Aclacinomycin ZIMET 33352—a new anthracycline antibiotic
Authors: Dornberger K. , Eckardt K. , Ihn W. , Tresselt D. , Schumann G. 
Published: February 2007

AbstractA new anthracycline, aclacinomycin ZIMET 33352, has been isolated from cultures of Streptomyces spec. AM 33352/NG 3–11.
Detection of an insensitive ornithine‐carbamoyltransferase in strains of Pseudomonas syringae pv. phaseolicola with different phytotoxin‐generating capacities
Authors: Jahn O. , Sauerstein J. , Laplace F. , Reuter G. 
Published: February 2007

AbstractIndependently of their capacity to produce phytotoxins, strains of Pseudomonas syringae pv. phaseolicola contain two ornithine carbamoyltransferases (OCT, EC 2.1.3.3.) which differ in resistance to phaseolotoxin and Orn‐P(O) (NH2)‐NH‐SO3 H (PNSOrn). At 18 °C, the optimal temperature for product formation, the balance of the two types of OCT was shifted in favour of the insensitive type in phaseolotoxin producing strains, and in favour of the sensitive one in strains with little or no toxin production. The results suggest a causal relationship between the existence of an insensitive enzyme and the synthesis of toxins.