The Structure of the Cell Walls of Aspergillus and the Theory of Cellulose Particles

Castle, E. S.

doi:10.1002/j.1537-2197.1945.tb05099.x

Cited by 5 publications

(1 citation statement)

References 24 publications

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“…On the other hand, the thickness of the external membrane depends on several parameters such as the fungal species, the cell type, the growth conditions including the nutrient and the maturity of the species. As an example, the hyphen walls of Aspergillus nidulans varies between 44 and 48 nm depending on the grown temperature (Kaminskyj et al, 2004) the vesicle wall of the Aspergillus clavatus is 500 nm thick (Hanlin, 1976), while in the young conidiophore of Aspergillus the primary wall does not exceed 500 nm (Castle, 1945). In addition, transmission electron microscopy revealed that the conidial wall of the wild-type Aspergillus nidulans strain was composed of three layers an irregular, electron-dense outer layer varying from 40 nm to 190 nm in thickness; an electrontranslucent middle layer 40-70 nm thick; and a thin, electron-dense inner layer 10-15 nm thick, which is intimately associated with the plasma membrane (Martin et al, 1988).…”

Section: Spores Irradiated With Low Intensity Vuv Photons At 10 -4 Pamentioning

confidence: 99%

Interplanetary survival probability of Aspergillus terreus spores under simulated solar vacuum ultraviolet irradiation

Sarantopoulou¹,

Gomoiu²,

Kollia³

et al. 2011

Planetary and Space Science

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This work is a part of ESA/EU SURE project aiming to quantify the survival probability of fungal spores in space under solar irradiation in the vacuum ultraviolet (VUV) (110-180 nm) spectral region. The contribution and impact of VUV photons, vacuum, low temperature and their synergies, on the survival probability of Aspergillus terreus spores is measured at simulated space conditions on Earth. To simulate the solar VUV irradiation, the spores are irradiated with a continuous discharge VUV hydrogen photon source and a molecular fluorine laser, at low and high photon intensities at 10 15 photon m -2 s -1 and 3.9 x 10 27 photons pulse -1 m -2 s -1 respectively. The survival probability of spores is independent from the intensity and the fluence of photons, within certain limits, in agreement with previous studies. The spores are shielded from a thin carbon layer, which is formed quickly on the external surface of the proteinaceous membrane at higher photon intensities at the start of the VUV irradiation. Extrapolated the results in space conditions, for an interplanetary direct transfer orbit from Mars to Earth, the spores will be irradiated with 3.3 x 10 21 solar VUV photons m -2 . This photon fluence is equivalent to the irradiation of spores on Earth with 54 laser pulses with an experimental ~92% survival probability, disregarding the contribution of space vacuum and low temperature, or to continuous solar VUV irradiation for 38 days in space near the Earth with an extrapolated ~61% survival probability. The experimental results indicate that the damage of spores is mainly from the dehydration stress in vacuum. The high survival probability after 4 days in vacuum (~34 %), is due to the exudation of proteins on the external membrane, preventing thus further dehydration of spores. In addition, the survival probability is increasing to (~54%) at 10 K with 0.12 K/s cooling and heating rate.

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Section: Spores Irradiated With Low Intensity Vuv Photons At 10 -4 Pamentioning

confidence: 99%