# ALBERT

## All Library Books, journals and Electronic Records Telegrafenberg

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• 1
Electronic Resource
Amsterdam : Elsevier
ISSN: 0305-0491
Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
Topics: Biology , Chemistry and Pharmacology
Type of Medium: Electronic Resource
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• 2
Electronic Resource
Springer
Applied microbiology and biotechnology 19 (1984), S. 139-139
ISSN: 1432-0614
Source: Springer Online Journal Archives 1860-2000
Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
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• 3
Electronic Resource
Springer
ISSN: 1432-0614
Source: Springer Online Journal Archives 1860-2000
Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
Notes: Summary Beneckea natriegens was grown in continuous culture at various growth rates under nitrogen limitation in the presence of excess unmetabolised glucose. The bacterial protein content (% dry weight) varied significantly with growth rate, but as the absolute amount of bacterial protein in the culture was independent of growth rate the latter was used in the calculation of kinetic data instead of bacterial dry weight. Under carbon-excess conditions glucose was overmetabolised to extracellular products and a maximum yield of 0.53 g product C·g−1 glucose C was observed at D=0.04 h−1. The yield of soluble metabolic products decreased and the yield of cells increased with increasing growth rate. Although the rate of total product carbon production increased with growth rate, the concentration of products decreased with growth rate. Oxoglutarate and ethanol were the two major products identified and at D=0.04 h−1 accounted for 53% of the product carbon. Ethanol was produced under fully aerobic conditions and its rate of production was independent of growth rate, as observed for oxoglutarate. Although the yield of products was high at low growth rate (Yp=0.53 gC·g−1C at D=0.04 h−1) the rate of glucose uptake expressed under these conditions was only a fraction of the maximum uptake rate capable by the organism. Surprisingly, under carbon-excess conditions the respiration rate was tightly controlled as the YO2 of both carbon limited and excess cultures were virtually identical at all growth rates examined.
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• 4
Electronic Resource
Springer
Applied microbiology and biotechnology 25 (1987), S. 357-361
ISSN: 1432-0614
Source: Springer Online Journal Archives 1860-2000
Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
Notes: Summary Agrobacterium radiobacter NCIB 11 883 does not produce gluconate under conditions of glucose excess in batch or continuous culture. However, the addition of micromolar concentrations of pyrrolo quinoline quinone (PQQ) to fermentation media resulted in rapid excretion of gluconate by batch and continuous cultures. This rapid dehydrogenation of glucose was found in cells grown under carbon and nitrogen limitation and is constitutive which suggests that the only reason why this activity is not normally expressed is due to the inability of the organism to synthesize the prosthetic group (PQQ) of the glucose dehydrogenase enzyme. Although the addition of PQQ to batch and continuous cultures caused a very rapid specific rate of gluconate production (0.6–1.1 g gluconate g-1 dry wt. h-1) the rate of exopolysaccharide production remained unaltered. Indeed, when the rates of substrate and oxygen uptake are corrected for the rate of gluconate production in the presence of PQQ there appears to be little physiological consequence as a result of this oxidation.
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• 5
Electronic Resource
Springer
Archives of microbiology 129 (1981), S. 119-122
ISSN: 1432-072X
Keywords: Beneckea natriegens ; Glucose formate ; Yields
Source: Springer Online Journal Archives 1860-2000
Topics: Biology
Notes: Abstract Beneckea natriegens oxidizes sodium formate constitutively when grown on glucose or glycerol in chemostat culture, but cannot utilize formate as the sole source of carbon and energy for growth. However, when grown on a mixture of glucose and formate (D=0.37 h-1, pH 7.6) the yield is higher than on glucose alone. The yield, expressed in terms of g bacterial dry weight g-1 glucose plus formate carbon utilized, gave a linear relationship when plotted against the total heat of combustion of glucose plus formate utilized. Extrapolation of the plot cut the abscissa at a value equivalent to the heat of combustion of formate, which suggests that formate is not utilised as a source of carbon but only energy. In cultures with nitrate as the sole source of nitrogen the yield from glucose was lower than that observed with ammonia but the addition of formate to the culture utilizing nitrate resulted in an increase in the yield from glucose to a value similar to that observed with ammonia. At a culture pH value of 7.65 unused formate (〈0.15–227 mM) in the culture supernatant had no effect on respiration spiration or yield, but at a culture pH of 6.7 excess formate caused a marked increase in respiration rate and a large decrease in the yield from glucose; further decrease in the pH value caused washout of the culture. This may be explained by undissociated formic acid causing uncoupling of oxidative phosphorylation.
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• 6
Electronic Resource
Springer
Archives of microbiology 117 (1978), S. 41-48
ISSN: 1432-072X
Keywords: Methylococcus ; Methane ; Chemostat ; Ammonia limitation ; Intracellular polyglucose
Source: Springer Online Journal Archives 1860-2000
Topics: Biology
Notes: Abstract The accumulation of intracellular storage granules (0.03–0.5 μm) byMethylococcus NCIB 11083 when grown under conditions of ammonia limitation with methane as the sole source of carbon and energy was inversely proportional to the dilution rate. The isolated material was composed entirely of glucose residues and the infra-red spectrum exhibited characteristic absorption bands at 925 cm-1, 845 cm-1 and 745±4 cm-1, indicating the presence of α (1→4) glycosidic linkages. The polymer dissolved in hot water to give an opalescent solution that formed a violet iodine complex with an absorption maximum at 550 nm, identical to that observed with reference amylopectin. The percentage of the polysaccharide released as maltose by the action of β- and α-amylases was 55–64% and 80–90% respectively, values very similar to those obtained by the action of these enzymes on reference amylopectin and glycogen. Methylation analysis indicated that the average interior and exterior chain lengths of the polymer were 2.7 and 10.0 glucose units respectively and confirmed that theMethylococcus polyglucose is a branched polymer composed of units joined by 1→4 and 1→6 linkages. The number average molecular weight of the polymer is 2–4.5×105. The stored polymer was metabolised by the organism and its metabolism resulted in the synthesis of protein.
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• 7
Electronic Resource
Chester : International Union of Crystallography (IUCr)
Journal of synchrotron radiation 8 (2001), S. 972-974
ISSN: 1600-5775
Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics: Geosciences , Physics
Notes: Gas hydrates constitute a class of solids in which small molecules occupy cavities inside an ice-like structure. There is enormous scientific and technological interest in understanding the structure, stability and formation mechanism of clathrates. A variable-temperature high-pressure cell for X-rays measurements has been developed and constructed, which allows in situ studies of clathrate formation or decomposition. XAFS and diffraction techniques have been used to study the evolution of the structure during formation and decomposition. Two clathrates structures were studied, structure I (Xe) and structure II (Kr), and the local structure around the guest atom was identified. The rare gas-water complexes that act as precursor to the formation of the crystalline phases were identified. The transformation of the clathrate from structure II to structure I when Xe is added to Kr clathrates was observed.
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• 8
Electronic Resource
Springer
Physics and chemistry of minerals 22 (1995), S. 251-258
ISSN: 1432-2021
Source: Springer Online Journal Archives 1860-2000
Topics: Chemistry and Pharmacology , Geosciences , Physics
Notes: Abstract An exploratory high-pressure study of the join CaTiO3-FeTiO3 has uncovered two intermediate perovskites with the compositions CaFe3Ti4O12 and CaFeTi2O6. These perovskites have ordering of Ca2+ and Fe2+ on the A sites. Both of these perovskites are unusual in that the A sites containing Fe2+ are either square planar or tetrahedral, due to the particular tilt geometries of the octahedral frameworks. For CaFe3Ti4O12, the structure has been refined from a powder using the Rietveld technique. This compound is a cubic double perovskite (SG Im $$\bar 3$$ , a = 7.4672 Å), isostructural with NaMn7O12. Fe2+ is in a square-planar A site (similar to Mn3+ in NaMn7O12) with Fe-O = 2.042(3) Å, with distant second neighbors in a rectangle at Fe-O = 2.780(6) Å. Calcium is in a distorted icosahedron with Ca-O =2.635(5) Å. CaFeTi2O6 crystallizes in a unique tetragonal double perovskite structure (SG P42/nmc, a = 7.5157(2), c = 7.5548(2)), with A-site iron in square-planar (Fe-O = 2.097(2) Å) and tetrahedral (Fe-O = 2.084(2) Å) coordination, again with distant second neighbor oxygens near 2.8 Å. Rietveld refinement was also performed for the previously known perovskite-related form of FeTiO3 recovered from high pressure (lithium niobate type). This compound is trigonal R3c, with a = 5.1233(1) and c = 13.7602(2). The ordered perovskites appear to be stable at 1215 GPa and CaFe3Ti4O12 is found as low as 5 GPa. Thus these perovskites may be important to upper mantle mineralogy, particularly in kimberlites. These compounds are the first known quenchable perovskites with large amounts of A-site ferrous iron, and add greatly to the known occurrences of ferrous iron in perovskites.
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• 9
Electronic Resource
New York, NY : Wiley-Blackwell
Journal of Morphology 156 (1978), S. 419-437
ISSN: 0362-2525
Keywords: Life and Medical Sciences ; Cell & Developmental Biology
Source: Wiley InterScience Backfile Collection 1832-2000
Topics: Biology , Medicine
Notes: Testis structure in four species of goodeid teleosts is described. Testicular tubules terminate blindly at the testis periphery where spermatogonia are located. In goodeid teleosts, development of sperm takes place synchronously within cysts whose periphery is made up of a single layer of Sertoli cells. Upon completion of spermiogenesis, spermiation ensues wherein sperm are shed, as spermatozeugmata, into the testis efferent duct system. Subsequently, Sertoli cells, which comprised the cyst periphery, transform into efferent duct cells.Sertoli cells phagocytize residual bodies and are involved in the formation of spermatozeugmata. The structure of the goodeid spermatozeugmatum is quite different from that observed in the related poeciliids. It is concluded, in view of this and other considerations, that the goodeids and poeciliids have independently evolved solutions to the problems of internal fertilization and gestation.
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• 10
Electronic Resource
New York, NY [u.a.] : Wiley-Blackwell
Biotechnology and Bioengineering 26 (1984), S. 1455-1464
ISSN: 0006-3592
Keywords: Chemistry ; Biochemistry and Biotechnology
Source: Wiley InterScience Backfile Collection 1832-2000
Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
Notes: The yield from glucose of ammonia-grown carbon-limited continuous cultures of Penicillium stipitatum was ca. 20% higher than that of nitrate-grown cultures at all growth rates examined. However, the yield from oxygen was similar during growth on both nitrogen sources. Under phosphate limitation the specific rate of gluconic acid and stipitatic acid production increased with growth rate, but the former product accounted for virtually 100% of the excreted carbon. Stipitatic acid was not produced under nitrogen limitation, and glucose supplied to the culture in excess of that required for growth was virtually quantatively converted into gluconic acid. Productivities of 11.4 g gluconic acid/L/h were stably maintained in continuous culture. Under conditions of glucose excess the enzyme glucose oxidase was excreted into the culture. The specific activity of this extracellular enzyme increased when the input glucose concentration to the culture was progressively increased. The excretion of a protein under nitrogen limitation suggests that this enzyme plays an important role under these conditions. Indeed, it was demonstrated that nitrogen-limited cultures did not overmetabolize gluconate at either pH 6.5 or 3.5, although up to 29 g/L gluconate was present in the culture. The Ygluconate and YO2 of C- and N-limited gluconate-grown cultures were similar indicating that the rapid conversion of glucose to gluconate probably affords a means of regulating carbon flow in this organism. Nitrogen-limited cultures of P. stipitatum overmetabolized glucose to a much greater extent than acetate, fructose, or gluconate.