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  • Electronic Resource  (20)
  • Chemistry  (14)
  • Chemical Engineering  (3)
  • Homoptera  (2)
  • Opuntia ficus-indica  (2)
  • Somatic embryogenesis  (2)
Material
  • Electronic Resource  (20)
  • 1
    ISSN: 1432-203X
    Keywords: Key words Agrobacterium tumefaciens ; Benzylisoquinoline alkaloids ; California poppy ; Eschscholzia californica Cham. ; Genetic transformation ; Somatic embryogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  An efficient Agrobacterium-mediated protocol for the stable genetic transformation of Eschscholzia californica Cham. (California poppy) via somatic embryogenesis is reported. Excised cotyledons were co-cultivated with A. tumefaciens strain GV3101 carrying the pBI121 binary vector. Except for the co-cultivation medium, all formulations included 50 mg l−1 paromomycin as the selective agent and 200 mg l−1 timentin to eliminate the Agrobacterium. Four to five weeks after infection, paromomycin-resistant calli grew on 80% of explants in the presence of 2.0 mg l−1 1-naphthaleneacetic acid (NAA) and 0.1 mg l−1 6-benzylaminopurine (BAP). Calli were cultured on somatic embryogenesis induction medium containing 1.0 mg l−1 NAA and 0.5 mg l−1 BAP, and somatic embryos were visible on 30% of the paromomycin-resistant calli within 3–4 weeks. Three to four weeks after the somatic embryos were transferred to phytohormone-free plant regeneration medium, 32% converted to paromomycin-resistant plants. Detection of the neomycin phosphotransferase gene and high levels of β-glucuronidase (GUS) mRNA and enzyme activity, and the cytohistochemical localization of GUS activity in all plant tissues confirmed the integrative transformation of the regenerated plants. The normal alkaloid profile of California poppy was unaffected by the transformation process; thus, the reported protocol could serve as a valuable tool to investigate the molecular and metabolic regulation of the benzophenanthridine alkaloid pathway.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Plant cell reports 19 (2000), S. 421-426 
    ISSN: 1432-203X
    Keywords: Key words California poppy ; Eschscholzia californica ; Plant regeneration ; Somatic embryogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The development of a rapid protocol for high-efficiency somatic embryogenesis and plant regeneration from seed-derived embryogenic callus cultures of California poppy (Eschscholzia californica Cham.) is reported. The optimized procedure required less than 13 weeks from the initiation of seed cultures to the recovery of plantlets and involved the sequential transfer of cultures onto solid Murashige and Skoog basal medium containing three different combinations of growth regulators. All steps were performed at 25  °C. Friable primary callus was induced from seeds of E. californica cultured on medium supplemented with 1.0 mg l−1 2,4-dichlorophenoxyacetic acid. The primary callus was transferred to medium containing 1.0 mg l−1 1-naphthaleneacetic acid and 0.5 mg l−1 6-benzylaminopurine to establish embryogenic callus and promote somatic embryogenesis. Regenerated plantlets were recovered after the conversion of somatic embryos on medium containing 0.05 mg l−1 6-benzylaminopurine and showed normal development. Embryogenic callus was induced at a frequency of 85%, an average of 45 somatic embryos were produced per callus, 90% of the somatic embryos converted, and about 70% of the plantlets were recovered in soil. The growth rate of somatic embryo-derived shoots could be increased by gibberellic acid treatment, but the resulting plantlets were hyperhydritic.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1573-5079
    Keywords: Crassulacean acid metabolism ; CO2 enrichment ; Opuntia ficus-indica ; PEPCase ; Rubisco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Responses of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPCase) to an elevated atmospheric CO2 concentration were determined along with net CO2 uptake rates for the Crassulacean acid metabolism species Opuntia ficus-indica growing in open-top chambers. During the spring 13 months after planting, total daily net CO2 uptake of basal and first-order daughter cladodes was 28% higher at 720 than at 360 μl CO2 l-1. The enhancement, caused mainly by higher CO2 assimilation during the early part of the night, was also observed during late summer (5 months after planting) and the following winter. The activities of Rubisco and PEPCase measured in vitro were both lower at the elevated CO2 concentration, particularly under the more favorable growth conditions in the spring and late summer. Enzyme activity in second-order daughter cladodes increased with cladode age, becoming maximal at 6 to 10 days. The effect ofelevated CO2 on Rubisco and PEPCase activity declined with decreasing irradiance, especially for Rubisco. Throughout the 13-month observation period, O. ficus-indica thus showed increased CO2 uptake when the atmospheric CO2 concentration was doubled despite lower activities of both carboxylating enzymes.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 12 (1986), S. 609-617 
    ISSN: 1573-1561
    Keywords: Sex pheromone ; interspecific attraction ; red pine scale ; Matsucoccus resinosae ; Matsucoccus n. sp. ; Pinus resinosa ; Pinus thunbergiana ; Homoptera ; Coccoidea ; Margarodidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In laboratory bioassays, males ofMatsucoccus resinosae fromPinus resinosa in New York andMatsucoccus n. sp. fromPinus thunbergiana in Korea were strongly attracted to crude hexane extracts ofM. resinosae females, andM. resinosae males responded strongly to extracts ofMatsucoccus n. sp. females. Males of the two species responded similarly to gas chromatographic fractions and subfractions of a pentane extract ofM. resinosae females. Sex pheromones of these two species appear to be the same or very similar.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1573-1561
    Keywords: Matsucoccus thunbergianae ; Homoptera ; Coccoidea ; Margarodidae ; black pine bast scale ; sex pheromone ; attractant ; (2E,4E6R,10R)-4 ; 6,10,12-tetramethyl-2,4-tridecadien-7-one ; matsuone ; monitoring ; detection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Attraction of (2E,4E,6R,10R)-4,6,10,12-tetramethyl-2,4-tridecadien-7-one [1; (6R,10R)-matsuone] and its antipode [2; (6S,10S)-matsuone] toMatsucoccus thunbergianae males was studied in the laboratory and in the field. They showed stronger response to1. In laboratory bioassays, the threshold concentrations for male attraction with1 and2 were 16 fg and 150 pg, respectively. In the field, during the first two days after traps were set, traps baited with 50 µg of1 on rubber septa or filter paper rolls caught more males than control traps. Between the sixth day and the tenth day after traps were set, in a daily trap catch experiment, the traps with 50 µg of1 on filter paper rolls caught more males than control traps on one day only, whereas those on rubber septa were always effective. The shape of the traps did not affect male catches. Males were caught on pheromone traps in locations where no scales were found by the customary detecting procedures.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Photosynthesis research 18 (1988), S. 277-286 
    ISSN: 1573-5079
    Keywords: CO2 uptake ; high-temperature acclimation ; Opuntia ficus-indica ; photosystems I and II ; whole chain electron transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Inhibition and recovery of net CO2 uptake and three photosynthetic electron transport reactions as well as plant survival following high-temperature treatments were investigated for Opuntia ficus-indica. For plants maintained at 30°C/20°C day/night air temperatures, treatment at 60°C for 1 h irreversibly inhibited net CO2 uptake and photosynthetic electron transport, resulting in plant death in about 60 days. When a plant maintained at 30°C/20°C was treated at 55°C for 1 h, net CO2 uptake was completely inhibited 1 d after the treatment but fully recovered in 60 d. Differential inactivation of photosystem (PS) I, PSII, and whole chain electron transport activities occurred; PSI was the most tolerant of 55°C and took the least time (45 d) for total recovery. All 30°C/20°C plants survived a 1-h treatment at 55°C, although some pale green areas were observed on the cladode surfaces. In contrast to growing at 30°C/20°C, plants acclimated to 45°C/35°C survived 60°C for 1 h without showing any necrotic or pale green areas on the cladode surfaces. When such a plant was transferred to 30°C/20°C following the high-temperature treatment, recovery in net CO2 uptake began in 1 d and progressed to complete recovery by 30 d. Growth temperatures thus influence the possibility for recovery of photosynthetic reactions and ultimately the survival of O. ficus-indica following a high-temperature exposure.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 38 (1991), S. 304-313 
    ISSN: 0006-3592
    Keywords: Zymomonas mobilis ; molasses ; fermentation ; ethanol ; osmolality ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new osmotolerant mutant strain of Zymomonas mobilis was successfully used for ethanol production from beet molasses. Addition of magnesium sulfate to hydrolyzed molasses allowed repeated growth without the need of yeast extract addition. The kinetics and yields parameters of fermentation on media with different molasses concentrations were calculated. The anabolic parameters (specific growth rate, μ, and biomass yield, YX/S) were inhibited at elevated molasses concentrations while the catabolic parameters (specific ethanol productivity, qp, and ethanol yield, Yp/s) were not significantly affected. In addition to ethanol and substrate inhibition, osmotic pressure effects can explain the observed results.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 1838-1844 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A carrier-supported mycelial growth of Penicillium chrysogenum was applied to penicillin fermentation system using celite as a support material. Hyphal growth through the pore matrices of the material showed strong anchorages and provided highly stable biofilm growth. With bioparticles developed in such a manner, both cell growth and penicillin production were observed to increase significantly compared to the conventional dispersed filamentous cultures. Maximum values of specific penicillin production rate were found to be constant regardless of the growth form. A three-phase fluidized-bed fermentor was designed and tested for penicillin production using the bioparticles. Two modes of operation, semicontinuous and repeated fed batch, of the fermentor were tried. It was noted that the overgrowth of free mycelia and the development of fluffy loose bioparticles caused poor mixing and made the fermentor operation quite difficult. Control of the bioparticle size and the extension of production phase were therefore considered important to maintain the reactor productivity at a desired level. From the results of repeated fed-batch operation it was found that the control of bioparticle size could be successfully achieved by phosphate-limiting culture condition. Penicillin production under this condition was also observed to be maintained at a high level (about 80% of the maximum) for at least 1 month.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 47 (1995), S. 696-702 
    ISSN: 0006-3592
    Keywords: Bacillis subtilis ; spore mutant ; fed-batch ; continuous culture ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: To alleviate plasmid instability and to prolong the production phase of subtilisin, integrable plasmid and spore mutants are used. Compared with batch-type shake flask cultures, spore mutants' ability to produce subtilisin can be well pronounced in fed-batch and continuous cultures. Hence, the two culture methods make it possible to identify the peculiar characteristics of the spore mutants unobtainable in batch culture. Spore mutants can enhance subtilisin productivity and prolong subtilisin production time in fed-batch culture as well as enable us to use very low dilution rates (〈0.1 h-1) without losing productivity in continuous culture, thereby improving the conversion yield of the nitrogen source. At 0.05 h-1 the spollG mutant of Bacillus subtilis DB104 (Δnpr Δapr) (Emr) spollG (Bimr):: pMK101 (Cmr) showed a subtilisin yield about ten times higher than that from wild-type DB104 (Δnpr Δapr)::pMK101 (Cmr). © 1995 John Wiley & Sons, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 23 (1992), S. 329-338 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Influence of grain size on mechanical properties and dry oscillating sliding wear of Al2O3-ceramicsSpecimens with average grain sizes varying between about 0.8 μm and 12 μm were produced by cold isostatic pressing of high purity Al2O3-powder followed by sintering between 1300°C and 1700°C. Hardness, Young's modulus, bending strength and fracture toughness were measured as a function of average grain sizes. Tribological tests were carried out on the different microstructures at normal laboratory air and room temperature by using a ring-on-block tribometer.Experimental results showed the dependence of mechanical properties on grain size, hardness and bending strength obeying a Hall-Petch type relation, approximately. Coefficient of friction was relatively independent of grain size under the test conditions used. However, wear intensity increased substantially if a critical grain size was surpassed. This was due to a change in mechanisms of material removal which was confirmed by scanning electron microscopical studies of the worn surfaces.
    Notes: Aus hochreinem Al2O3-Pulver wurden durch kaltisostatisches Pressen und Variation der Sintertemperatur zwischen 1300°C und 1700°C Formkörper mit unterschiedlichen mittleren Korngrößen zwischen etwa 0,8 und 12 μm hergestellt. Untersucht wurde der Einfluß der Korngröße auf mechanische und tribologische Eigen-schaften.Die Ergebnisse zeigten, daß mechanische Eigenschaften wie Härte, E-Modul, Biegebruchfestigkeit und Bruchzähigkeit von der Korngröße bzw. den Sintertemperaturen abhingen, wobei im Fall der Härte und Bruchfestigkeit näiherungsweise eine Hall-Peteh-Beziehung vorlag. Während die Reibungszahl relativ unabhängig von der Korngröße war, trat in der Verschleißintensität aufgrund geänderter Mechanismen ein starker Anstieg mit zunchmender Korngröße auf. Rasterelektronenmikroskopische Untersuchungen zeigten, daß der Verschleiß durch plastische Verformung, Mikrobruch, Kornfragmentierung und Deckschichten beeinflußt wurde.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
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