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  • 1
    ISSN: 1432-184X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The formation of microbial mats by thermophilic organisms on submerged rocks in radioactive thermal springs was followed quantitatively in situ as well as under experimental conditions, by determining the change in dry weight and organic matter as a function of time. Furthermore, the decay of the rock occurring in the springs could be shown to be directly related to the microbial colonization. Early in that process the formation of silicious gels, facilitating the settling of the organisms, could be observed. Simultaneously, this was accompanied by the leaching of silica from the underlying rock. This resulted in the destruction of the rock, which had been altered to a fine-grained dust underneath the colonizing mats; the microorganisms were found to move further downward within this layer. From the heavy metals present in the rock—iron (Fe), copper (Cu), manganese (Mn), uranium (U)— the leaching of uranium could be demonstrated, leading to the acquisition of this metal in the microbial mats in concentrations up to 15.34μg/mg dry weight. Direct evidence for the leaching of Si (silicon) and U could be obtained by measurement of these elements after their release from ground rock chips in cultures with microorganisms from the hot springs at 50°C. X-ray analysis of the biomats strongly suggested that Cu, Mn, and Fe are also accumulated.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 129 (1981), S. 127-128 
    ISSN: 1432-072X
    Keywords: Continuous culture ; Adaptation ; Simulation of hot springs ; Boiling point ; Caldoactive bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Bacillus caldolyticus, a caldoactive bacterium originating from a hot spring at Yellowstone Park, was grown in a defined medium, whose composition resembled that of the pool water. Using a chemostat culture, which simulated the natural conditions, the organism could be adapted to grow at 100°C at a reasonable rate. Under increased pressure growth occurred also at 105° C.
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  • 3
    Electronic Resource
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    Springer
    Archives of microbiology 130 (1981), S. 159-164 
    ISSN: 1432-072X
    Keywords: Adaptation ; Boiling point ; Caldoactive enzymes ; Stabilization ; Thermostability ; Thermal characteristics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In chemostat cultures of Bacillus caldolyticus, adaptation in a single step from 70–100°C was followed under aerobic and oxygen-limited conditions and was found to proceed more smoothly under the latter circumstances. Variations of the medium (e.g. yeast extract or silicate concentrations) showed that growth at 100°C is in all respects similar to that of cultures at moderate temperatures. Enzyme preparations derived from cultures at 5°C intervals between 70 and 100°C were used to determine the temperature range. For all nine enzymes tested, the optimum temperature was found to be 67°C; the latter was independent of the growth temperature. Differences were found, however, with respect to the maximum temperature of individual enzymes, and three groups, with maxima between 70 and 80°C, 80 and 90°C and 90 and 100°C can be distinguished. Again, there was no correlation with the growth temperature. Stability experiments also revealed that enzymes from the same organism can have different thermal properties: Some were found to be quite thermolabile (e.g. the pyruvate kinase), while others (e.g. hexokinase and glutamate-pyruvate transaminase) exhibited a high thermostability. These properties were not related to the growth temperature within the 70–100°C range, too. Six of the enzymes tested could be stabilized by their respective substrates, but the degree of protection varied for individual enzymes. Three enzymes (acetate kinase, glutamate dehydrogenase and myokinase) could not be stabilized by their substrates. Comparative experiments with the hexokinase suggested, that the thermal integrity of the enzymes is better protected within the cell as compared to the stability of the enzyme preparations.
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  • 4
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    Springer
    Archives of microbiology 41 (1962), S. 268-281 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Penicillium spinulosum is capable to attack the waxy materials of the leaves of Gasteria verricuosa and can thus penetrate to the leave's cuticular layer. 2. Besides cutinase, an enzyme that catalyses the lysis of cutin, other enzymes of the fatty acid breakdown have been found. The mold is thus able to attack the reaction products of cutinase. 3. Further pectolytic and cellulolytic activity could be demonstrated suggesting that P. spinulosum is able to attack all components of the cuticular layer.
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  • 5
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    Springer
    Archives of microbiology 82 (1972), S. 1-23 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The caldo-active strain YT-P was found to produce a variety of extracellular enzymes, including an amylase and a protease, which were further examined. With azo-casein as a substrate, optimum conditions with respect to enzyme and substrate concentration were determined for the protease. The optimum temperature was found to be 70°C, with a sharp decline to both lower and higher temperatures. The enzyme was found to be extremely heat-stabile, with unaltered activity after 8 hours at 80°C. Optimum conditions for the amylase were also examined. This enzyme was shown to be less heat-stabile, though the temperature optimum was again at 70°C. The activity or stability was not influenced by absence or presence of Ca-ions. The main activity of the amylase was found in the 20–40% ammonium sulfate fraction, which also contained the bulk of the proteolytic enzyme. This strain growth optimally on a variety of carbon sources at 72°C. Typical submicroscopical features are the double-layered cell wall, and a cytoplasmic membrane with a varying number of small dots and dot-free patches. Furthermore the nutritional requirements and submicroscopical features of two other strains, YT-G and YT-F, are described and compared to strain YT-P. Based on the fatty acid composition of the three spore forming caldo-active strains we suggest that they belong to the genus Bacillus, and propose the names B. caldolyticus for strain YT-P, B. caldovelox for strain YT-F, and B. caldotenax for strain YT-G.
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  • 6
    Electronic Resource
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    Springer
    Archives of microbiology 91 (1973), S. 241-254 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Bacillus caldolyticus, grown at 70°C, produces a highly active extracellular amylase and protease. Both enzymes are formed either within the membrane, or at its inner surface. The activity of both extracellular enzymes was found to decline drastically when brain-heart infusion was omitted from the medium. A simultaneous increase of both enzymes inside the cell was observed. The shifting in extra- and intra-cellular activity was caused by changes in membrane composition due to the increase of anteiso-odd and n-even, and the decrease of iso-odd fatty acids. Membrane composition and enzymic activity could be influenced by the addition of either leucine or iso-leucine as precursors for the synthesis of branched-chain fatty acids: In presence of leucine the anteiso-odd and n-even fatty acids returned to their normal level, while the iso-odd fatty acids increased. Simultaneously the extracellular protease activity increased, and the intracellular activity declined. Growth in amylose-medium supplied with leucine lead to a decrease of both the intra- and extracellular amylase, and changes in the fatty acid composition of the membrane which could not be restored by transfer of the organism to complete media. Addition of iso-leucine first lead to a sharp decrease of extracellular protease and a drastic increase of intracellular protease activity, accompanied by an increase of anteiso-odd and n-even fatty acids, and a decrease of iso-odd compounds. After the second growth in presence of iso-leucine the intra- and extra-cellular protease activity was reversed, and thus showed a return to the starting situation. The reversal is accompanied by the preferential incorporation of fatty acids with a higher melting point into the membrane. Extracellular amylase activity was found to increase after the first growth with iso-leucine, and to decline sharply after the second culture with iso-leucine, together with a very high intracellular amylase activity at that point. Extra- and intra-cellular amylase activity both declined upon growth in complete medium, while the fatty acid distribution remained different from the initial composition.
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  • 7
    Electronic Resource
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    Springer
    Archives of microbiology 112 (1977), S. 103-107 
    ISSN: 1432-072X
    Keywords: Alkaline phosphatase ; Adaptation ; Derepression ; Repression ; Phosphite ; Hypophosphite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When Escherichia coli cells were grown in media containing either phosphite or hypophosphite as the sole source of phosphorus, they responded to this situation primarily in the same way as phosphatelimited cultures: The activity of alkaline phosphatase increased drastically, which under natural conditions would enable the cells to compklensatae for the shortage increased drastically, which under natural conditions would enable the cells to compensate for the shortage of phosphate. Subsequent transfers, however, resulted in a quite different response: While the phosphatase activity of phosphate-limited cells stays at a high derepressed level, its increase was followed by a gradual decline in organisms grown on phosphite or hypophosphite. After eight to ten transfers on these P-compounds, phosphatase activity was back to its initial, repressed, low level, indicating that the cells were fully adapted to these substrates. Adaptation to either PO 3 3- or PO 2 3- was completely abolished if the cells were again grown with PO 4 3- as P-source, whereafter the entire process of adaptation had to be repeated. The observed adaptation pattern, reflected by the alterations of phosphatase activity, was qualitatively equal with PO 3 3- and PO 2 3- , but quantitatively different, because the response to hypophosphite gave much higher values than the increase obtained with phosphite. Phosphite-adapted cells are not simultaneously adapted to hypophosphite, but their response to the latter was less intense than observed after direct transfers from PO 4 3- to PO 2 3- . Adaptation to hypophosphite, however, led simultaneously to phosphite adaptation, so that these cells can utilize both P-compounds as a substitute for phosphate.
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  • 8
    Electronic Resource
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    Springer
    Archives of microbiology 31 (1958), S. 50-59 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Zusammenfassung 1. Ein Fettsäureabbau zu Methylketonen, der bisher nur für Aspergillaceen bekannt war, wurde allgemeiner, jedoch nicht ubiquitär bei Phycomyceten, Ascomyceten und Fungi imperfecti verbreitet gefunden. Die aktivsten Methylketonbildner stellten die Gattungen Rhizopus, Aspergillus, Penicillium, Neurospora, Sordaria, Botrytis und Cladosporium. 2. Das Maximum der Methylketonbildung aus Laurinsäure tritt nach 4–7 tägiger Inkubation bei 28° auf. Das pH-Optimum liegt im schwach sauren Gebiete (pH 5–7). Von den geradzahligen Fettsäuren liefert Buttersäure (C4) am meisten und am raschesten Methylketon (Aceton), von den höheren Fettsäuren (langsamer) die Laurinsäure (C12). Relativ schwach ist die Methylketonbildung bei den Säuren C8 und C10; sie fehlt bei Säuren oberhalb C14.
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  • 9
    Electronic Resource
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    Springer
    Archives of microbiology 54 (1966), S. 339-349 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Re-examination of the colorimetric fatty acid determination with copper nitrate, followed by complex formation with DIECA has shown that the method is not reliable if applied as described by Duncombe (1962, 1963): The Cu concentration is too high, the DIECA concentration much too low and the wavelength chosen (440 mμ) is suitable only for very low fatty acid concentrations. According to the results reported here the following alterations have to be adopted: The concentration of the copper nitrate solution should be 3%, a 0.5% solution of DIECA in butanol has to be used and measurements should be done at 492 mμ. The method described here offers the opportunity to determine fatty acid concentrations in the semi-micro range by measuring the filtered chloroform phase directly at 691 mμ, covering a range between 175 μg/ml to 1.2 mg/ml. If the concentration turns out to be lower than 200 μg F. A./ml, the same sample can be used for a micro-determination (up to 200 μg/ml) at 492 mμ, after formation of the yellowish-brown complex by addition of 0.1 ml 0.5% butanolic DIECA solution to 1.0 ml of the chloroform phase. The method has been applied to determine the amount of free F. A. in cutin layers and cutin powder, revealing that the latter contains 5.6 times more free F. A. than the intact material. The free F. A. within the polymer seem to serve as interconnections for the main units of the cutin polylipid.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Archives of microbiology 54 (1966), S. 331-338 
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Gartenerde enthält eine ganze Reihe von Mikroorganismen, die Cutin abbauen können: Von zehn isolierten Stämmen waren sieben cutinolytisch aktiv. 2. Auf Grund der analytischen Bestimmungen während des Cutinabbaus durch Cryptococcus laurentii und Rhodotorula sp. ergaben sich drei typische Abbauphasen. Diese drei Phasen stimmen überein mit drei Phasen von Sauerstoffverbrauch und-abgabe in Warburg-Ansätzen mit Rhodotorula sp. 3. Die dritte Abbau-Phase, die durch einen gleichmäßigen Verlauf der Oxydation und eine fortlaufende Hydrolyse des Cutins unter Freisetzung von Fettsäuren gekennzeichnet ist, beginnt bei dem untersuchten Bakterium nach 42 Std, bei Rhodotorula dagegen erst nach 120 Std. Durch Ermittlung der Zeit, die bis zum Einsetzen der dritten Phase verstreicht, ist eine Möglichkeit gegeben, relative Cutinase-Aktivitäten in verschiedenen Mikroorganismen vergleichsweise zu bestimmen. 4. Der Cutin-Abbau verläuft rascher, wenn das Cutin nicht als einzige C-Quelle geboten wird, sondern durch eine gute N- und C-Versorgung für optimale Wachstumsbedingungen gesorgt wird.
    Notes: Summary 1. Soil from cultivated land contains a variety of microorganisms, enabled to decay z. Seven out of ten isolated microorganisms were shown to contain cutinolytic enzymes. 2. The degradation of cutin by Cryptococcus laurentii and Rhodotorula sp. was found to proceed in a threestep pattern, according to the release of free F. A. from the substrate as determined analytically. 3. This pattern was shown to coincide with three stages of oxygen consumption and oxygen release in Warburg assays with Rhodotorula sp. 4. The third stage of cutin degradation, represented by a steady oxidation of continously released free F. A., starts after 42 hours with the Bacterium tested, and after 120 hours with Rhodotorula. Determination of the beginning of the third stage thus provides data for the comparison of cutinolytic activity in different microorganisms. 5. Cutin decomposition proceeds faster, if suitable C- and N-sources are provided with the incubation medium.
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