Biomedical subjects

G Kraepelin

Publications and source records attributed to G Kraepelin.

14 recordsLinked to original sources

PubMed1990

Influence of non-thermic AC magnetic fields on spore germination in a dimorphic fungus.

The influence of weak pulsed magnetic fields of low frequencies on the germination rate of Mycotypha africana was tested. This fungus grows as a mycelium (M-culture) or in a yeast-like form (Y-culture) depending upon culture conditions. 5 h and 24 h of field application enhanced the germination rate in a Y-culture up to 2 or 3 times at low intensity levels and decreased it up to a factor 4 at the intensity level "4". M-cultures exhibited the same reaction pattern after 5 h exposition and no effect after 24 h exposition. The Y/M ratio is shifted by low field intensities towards the Y-form. The occurrence of stimulation as well as retardation by neighbouring intensities is discussed.

Calcium↗

PubMed1983

Studies of protoplast fusion in Streptomyces chrysomallus.

Conditions for the regeneration of cells from protoplasts of Streptomyces chrysomallus, a producer of the peptide antibiotic actinomycin, are described. Regeneration of fusion products was most efficient at 27-30 degrees C on regeneration R2 medium (Okanishi et al., 1974) containing 0.25 M-sucrose. The addition of phosphate (150-300 mg 1(-1) to the medium and incubation at 23 degrees C proved to be optimal for the regeneration of individual strains. Highest recombination frequencies after protoplast fusion were obtained by fusing protoplasts in the presence of 45% (w/v) polyethylene glycol 6000. With strains that produce no, or little antibiotic, protoplasts must be present in excess in fusion mixtures in order to overcome inhibition of regeneration by the antibiotic-producing partner.

Dactinomycin↗

PubMed1983

Cell-free synthesis of the depsipeptide beauvericin.

The enzymatic formation of the cyclodepsipeptide beauvericin was demonstrated in cell-free extracts from Beauveria bassiana. In analogy to the enniatin synthetase system formation of beauvericin is strictly dependent on the presence of the constituent amino and hydroxy acid, S-adenosylmethionine, and ATP/Mg2+. Synthesizing activity could be enriched about 12-fold by fractional ammonium sulfate precipitation. Besides the enniatin synthetase system this represents another example of the cell-free synthesis of a depsipeptide from eucaryotic origin.

Anti-Bacterial Agents↗

PubMed1982

Sterigmatosporidium gen. n., a new heterothallic basidiomycetous yeast, the perfect state of a new species of Sterigmatomyces fell.

Sterigmatosporidium gen. n. is described as a new basidiomycetous yeast-like fungus with the single species Sterigmatosporidium polymorphum sp. n. for which a Latin diagnosis and a preliminary life cycle are presented. The mean character distinguishing the new genus from the imperfect genus Sterigmatomyces is the development of a dikaryotic mycelium with clamp connections producing sexual spores in ramified whorls and lateral chlamydospores as well as blastospores. The dikaryotic phase could be induced by crossing compatible haploid clones of the heterothallic fungus, which are similar to Sterigmatomyces but not identical with any known species.

Basidiomycota↗

PubMed1980

[Experimental induction of rotund bodies in Thermus equaticus].

With several isolates of T. aquaticus rotund bodies (rbs) have been artificially induced. The most active agents were lysozyme, pronase (not trypsin), cellulase (not alpha-amylase or beta-glucosidase), penicillin and some mineral salts. Two modifications of rbs were observed: the vesticular type arising from single cells or filaments and the aggregate-rbs resulting from secondary associations of several cells or filaments. In both cases the primary event is a partial detachment of the outer layer of cell envelopes followed by its swelling to form a hyaline bleb. Within these osmotically stable blebs cells and/or filaments involved in the ribs production become irreversibly trapped. Appearance of filaments and rbs in stationary phase cultures are discussed as a consequence of unbalanced growth culminating in abnormal autolytic reactions.

Amylases↗

PubMed1980

[Gelatinous deposits of a special microbial population on pitwood].

Conspicuous gelatinous deposits found on permanently drenched pitwood planks in an old ore mine were analyzed microscopically. They contained a very characteristic microbial community consisting primarily of bacteria producing various kinds of slime capsules, stalks, hyphae or other appendages. The high degree of morphological diversity and the remarkable enrichment of differentiated cell types may reflect selective advantages realized under the continuous pressure imposed by such an unusual biotope.

Bacteria↗

PubMed1974