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Biomedical subjects

H P RUSCH

Publications and source records attributed to H P RUSCH.

At least 19 recordsLinked to original sources
PubMed1963

ORGANIC REQUIREMENTS AND SYNTHETIC MEDIA FOR GROWTH OF THE MYXOMYCETE PHYSARUM POLYCEPHALUM.

Daniel, John W. (University of Wisconsin, Madison), Karlee L. Babcock, Alice H. Sievert, and Harold P. Rusch. Organic requirements and synthetic media for growth of the myxomycete Physarum polycephalum. J. Bacteriol. 86:324-331. 1963.-An isolate of Physarum polycephalum was maintained in submersed pure culture in a completely defined medium, giving cell yields approximately 70% of those obtained in a partially defined medium. Optimal concentrations of the absolute organic requirements, identified as d- or l-methionine, biotin, thiamine, and hematin as previously reported, were established. Glycine was highly stimulatory. In a minimal medium, alanine or glutamine, not required in the complete medium, stimulated growth and appeared to function as sources for transamination. Arginine was also required in the minimal medium. The cell yield in a simplified medium containing the absolute requirements plus glycine, alanine, and arginine was approximately the same as that in the complete medium, but the growth rate was about 25% lower.

Biotin↗
PubMed1962

Method for inducing sporulation of pure cultures of the myxomycete Physarum polycephalum.

Daniel, John W. (University of Wisconsin, Madison) and Harold P. Rusch. Method for inducing sporulation of pure cultures of the myxomycete Physarum polycephalum. J. Bacteriol. 83:234-240. 1962.-Techniques for inducing sporulation of pure cultures of Physarum polycephalum are described. Small plasmodia grown in agitated culture were harvested, allowed to fuse into large plasmodia (1.3 g wet weight each), and, after incubation in the dark on a salts medium, exposed to light for 2 hr. The ensuing formation of sporangia containing spores was complete after 12 to 16 hr. The obligatory conditions for sporulation are: (i) an optimal growth age occurring just prior to the maximal growth of the organism and at a time when nutrients in the medium are exhausted; (ii) 4 days of incubation on a medium containing only inorganic salts and niacin or tryptophan; and (iii) subsequent illumination with light of wavelengths between 350 and 500 mmu.

Light↗
PubMed1962

Niacin requirement for sporulation of Physarum polycephalum.

Daniel, John W. (University of Wisconsin, Madison, Wis.) and Harold P. Rusch. Niacin requirement for sporulation of Physarum polycephalum. J. Bacteriol. 83:1244-1250. 1962.-The myxomycete Physarum polycephalum undergoes sexual sporulation if exposed to light after 4 days of incubation in the dark on a salts medium containing niacin, niacinamide, or tryptophan. None of these compounds is required for growth. Quinic acid, shikimic acid, intermediates of the kynurenine pathway, diphosphopyridine nucleotide (DPN), and triphosphopyridine nucleotide (TPN) replace niacin but a number of other tryptophan metabolites do not. Analogues of niacin inhibit sporulation when added at the beginning but not at the end of dark incubation with niacin. Folic acid, p-aminobenzoic acid, and p-aminobenzenesulfonamide inhibit sporulation if added at any time during the incubation or illumination periods. Reduced di- or triphosphopyridine nucleotide, but not DPN or TPN, reverse the p-aminobenzoic acid inhibition but do not replace the light requirement or shorten the dark incubation period. Gluconate and 2-ketogluconate also replace niacin. Glucose, pyruvate, malate, and oxalacetate inhibit the niacin-induced sporulation. Iodoacetate and fluoride do not counteract the glucose effect or inhibit sporulation.

4-Aminobenzoic Acid↗
PubMed1962

Hematin--requiring plasmodial myxomycete.

Daniel, John W. (University of Wisconsin, Madison), Jacqueline Kelley, and Harold P. Rusch. Hematin-requiring plasmodial myxomycete. J. Bacteriol. 84:1104-1110. 1962.-The myxomycete Physarum polycephalum, previously shown to require chick embryo extract for growth on a partially defined, soluble medium, grows as well if hematin or certain hemoproteins are substituted for the embryo extract. Hematin is also required as a growth factor if the organism is grown on a synthetic medium. Of the variety of porphyrins tested only iron protoporphyrin IX is utilized for growth by P. polycephalum. Protoporphyrin IX is inactive. Protein-bound iron porphyrin is active at one-tenth the concentration of free hematin. Although hematin completely replaces embryo extract, the extract activity has properties not characteristic of hematin or the hemoproteins tested: ladility to light and rapid plasmodial uptake.

Animals↗