CYTOLOGICAL STRUCTURE OF <i>ASPERGILLUS NIGER</i> BY ELECTRON MICROSCOPY

Tsukahara, Tohru; Yamada, Masako

doi:10.1111/j.1348-0421.1965.tb00273.x

Cited by 15 publications

(5 citation statements)

References 20 publications

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“…5). Similar observations have been recorded by Tsukahara and Yamada (24) with A. n iger hyphae. In contrast, hyphal walls containing 28% hot-water-extractable nigeran had only a wide nonstainable component (Fig.…”

Section: Resultssupporting

confidence: 90%

Distribution and conformation of crystalline nigeran in hyphal walls of Aspergillus niger and Aspergillus awamori

Bobbitt¹,

Nordin²,

Roux³

et al. 1977

J Bacteriol

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Hyphal walls ofAspergillus awamori containing increased amounts of the aglucan, nigeran, became correspondingly more opaque when viewed in the electron microscope as shadowed preparations. However, increased polymer deposition was not accompanied by any significant change in wall thickness. The nigeran of both A. awamori and Aspergillus niger occurred in situ in a crystalline conformation identical to that of single crystals prepared with pure polysaccharide. Furthermore, this polymer was the dominant crystalline material in the hyphae whether or not they were enriched in nigeran. Enzymic digestion of nigeran in A. niger and A. awamori revealed that the bulk of the polymer was exposed to the cell's exterior. However, a certain fraction was accessible to enzymic attack only after the wall was treated with boiling water. A third portion, detectable only by X-ray diffraction, was associated with other components and could not be extracted, even with prolonged boiling. It was removed by hot, dilute alkali and was associated in the wall with another glucan fraction. Dry heating of A. niger walls altered their susceptibility to enzymic digestion of nigeran in situ. It is proposed that this treatment introduces interstices in the crystal surface that facilitate attack. MATERIALS AND METHODS Growth of organism. A. awamori Nakazawa QM 873 (A. luchuensis3 was grown from spores aerobically in submerged cultures at room temperature (22 to 23°C) in a complete medium consisting of (per liter of deionized water): sucrose (30.0 g), NH4NOQ (1.0 g), MgSO4 7H20 (0.3 g), KH2PO4 (1.26 g), yeast 691

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Section: Resultssupporting

confidence: 90%

Distribution and conformation of crystalline nigeran in hyphal walls of Aspergillus niger and Aspergillus awamori

Bobbitt¹,

Nordin²,

Roux³

et al. 1977

J Bacteriol

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“…No evidence of the type of granules seen in A. niger (Tsukahara & Yamada, 1965) has been found in the present work.…”

Section: Discussioncontrasting

confidence: 78%

“…The septal pore of A . niger was described by Tsukahara & Yamada (1965) as an electron-transparent area in the centre of the septum.…”

Section: Discussionmentioning

confidence: 99%

Fine Structure of Vegetative Hyphae of Aspergillus fumigatus

Campbell¹

1970

Journal of General Microbiology

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“…4, 7-9). The conidium nucleus has been found to be similar in structural detail to that described for the parent hyphal cells [10] and vegeta-tive cells of other fungi. It is enclosed by an unit membrane (nuclear membrane) separated by a lighter interspace.…”

Section: Observations Of Sectioned Conidiosporesmentioning

confidence: 53%

“…Osmium tetroxide, on the other hand, was not adequate as a fixative for these intracytoplasmic organelles, but was of much use in preserving the outer surface structures of the conidia. Recently, it has been found that uranyl nitrate treatment of the whole cells of certain fungi after permanganate fixation was effective in preserving their membrane structures and for enhancing general contrast [10,11]. However, the application of uranyl nitrate after permanganate fixation of conidiospores of A. niger failed to yield a thin section of better contrast because of the greater condensation of cytoplasmic materials.…”

Section: Results and Discsionmentioning

confidence: 99%

Micromorphology of Conidiospores of Aspergillus niger by Electron Microscopy

Tsukahara

Yamada

Itagaki

1966

Japanese Journal of Microbiology

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The fine structure of conidiospores of Aspergillus niger has been studied by means of ultrathin sectioning and electron microscopy. Permanganate fixation of the conidia preserved the details of their inner structural components and enhanced the general contrast within the sections. The conidiospores are characerized by their peculiar surface structures composed of three distinct components; an outer hull, a spore coat or wall, and an intermediate space. As a consequence of the swelling of the conidia, both the outer hull and the intermediate space almost completely disappear, and a variety of the intracytoplasmic organelles becomes visible in large numbers. The mature conidia at the resting stage appear to possess a more electron-dense cytoplasm than that of the parent hyphae of the organism. They also contain a nucleus and a few mitochondria within the cytoplasm. The significance of these structures and their relationship to the parent hyphal cells are discussed.

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CYTOLOGICAL STRUCTURE OF ASPERGILLUS NIGER BY ELECTRON MICROSCOPY

Cited by 15 publications

References 20 publications

Distribution and conformation of crystalline nigeran in hyphal walls of Aspergillus niger and Aspergillus awamori

Distribution and conformation of crystalline nigeran in hyphal walls of Aspergillus niger and Aspergillus awamori

Fine Structure of Vegetative Hyphae of Aspergillus fumigatus

Micromorphology of Conidiospores of Aspergillus niger by Electron Microscopy

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