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N J Kreger-van Rij

Publications and source records attributed to N J Kreger-van Rij.

14 recordsLinked to original sources
PubMed1978

Ultrastructure of the ascospores of the new yeast genus Sporopachydermia Rodrigues de Miranda.

Development of the ascospores of Sporopachydermia lactativora and S. cereana was studied in ultrathin sections. The spores have a very thick wall consisting of a thin dark outer layer and a double light inner layer the outer part of which is very wide and often irregular. During germination, this part disappears, the outer dark layer breaks up and the inner part of the light layer remains around the protoplast during development to a vegetative cell.

Cell Wall↗
PubMed1977

Ultrastructure of Hanseniaspora ascospores.

A comparative study of the ultrastructure in sections of the ascospores of six Hanseniaspora species showed three types of spores: (1) hat-shaped in H. valbyensis and H. guilliermondii, (2) spherical with an equatorial or subequatorial ledge, smooth or rough in H. occidentalis and H. uvarum, (3) spherical with warts in H. osmophila and H. vineae. Development and germination of the spores of Hanseniaspora guilliermondii is described in more detail.

Cell Nucleus↗
PubMed1977

Electron microscopy of sporulation in Schwanniomyces alluvius.

Sporulation in Schwanniomyces alluvius appeared to be preceded by fusion of a mother and daughter cell. Meiosis probably occurred in the mother cell and one or two spores were formed in the latter. A study of thin sections showed that the spore wall developed from a prospore wall. The mature spore wall consisted of a broad light inner layer and a thinner dark outer layer including warts. An equatorial ledge was present. During germination in the ascus, a new light inner layer was formed and the old layers of the spore wall partly broke up. Ascospores in a strain of S. persoonii had a different wall structure in that the dark layer had changed into light areas separated by dark material which formed bulges at the surface.

Cell Wall↗
PubMed1976

Ultrastructure of the ascospores of some species of the Torulaspora group.

Development and germination of the ascospores in species of the Torulaspora group of yeasts have been described. Most species had warty spores which, in sections, showed a dark outer layer consisting of the outer unit membrane of the prospore wall and a layer underneath formed at an early stage of development of the spores. In mature spores the light inner layer of the wall was delimited at the outside by a thin dark layer. The warts often contained dark material. The ascospores of two Pichia and three Debaryomyces species were studied for comparison; they differed in sections from the Torulaspora spores. The taxonomic implications of the ultrastructural observations have been discussed.

Pichia↗
PubMed1976

Conjugation in the yeast Guilliermondella selenospora Nadson et Krassilnikov.

Conjugation in Guilliermondella selenospora took place via conjugation tubes from cells in different hyphae. Afterwards, a septum was formed in the channel connecting the two cells which turned into asci or formed buds which became asci. Conjugation between adjacent hyphal cells was also found. Cell contact without fusion with denticles and stalks, which occurs in G. selenospora, was compared with conjugation.

Ascomycota↗
PubMed1975

Microbodies in methanol-assimilating yeasts.

Cells of 3 yeast species capable of assimilating methanol have been examined by electron microscopy. When grown on methanol as the sole source of carbon and energy they contained many microbodies. Cells grown on glucose or ethanol either did not contain such bodies at all, or only to a limited extent.

Ascomycota↗
PubMed1973

Electron microscopy of some special cell contracts in yeasts.

Anastomosis in Endomycopsis javanensis and some other filamentous yeasts was brought about by contact of a denticle from one cell with the wall of another cell, resulting in the disappearance of the outer layer and the thickening of the inner layer of the cell wall of the contacted cell. Another form of contact between cells was the penetration of one cell by a denticle on another cell which had grown out to a stalk; this occurred between cells of E. javanensis and between cells of this species and other yeast species.

Candida albicans↗