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SUMMARYA wild strain of the multinucleate plasmodial myxomycete Physarum polycephalum was isolated in pure culture and grown on a medium consisting of 1 yo (w/v) Tryptone, 1% (w/v) glucose, 0.15% (w/v) yeast extract, 0.3% (w/v) CaCO,, inorganic salts and a small amount of chick embryo extract. The organism may be grown with this medium either as a single large plasmodium on surface culture, or as a suspension of tiny plasmodia in submerged culture. From an initial inoculum of 1 ml. of a %day culture, the average plasmodial yield in a submerged culture was about 80 mg. dry weight/20 ml. medium a t 72 hr. Growth occurred only in the presence of small amounts of an unidentified factor which was present particularly in chick embryo extract and foetal calf serum. An isolate of P. polycephalum was grown continuously on this medium for over four years without an appreciable decrease in growth rate. Under proper conditions a suspension of tiny plasmodia from shaken culture will fuse to form a single large surface plasmodium which exhibits synchronous mitosis.

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The effect on several anti-nutritional factors in cowpeas (Vigna unguiculata L. Walp) was investigated following treatment at 100 degrees C or 121 degrees C with solutions (0.1% w/v) of kanwa rock salt or NaHCO3 in distilled water. The concentration of polyphenols, calculated as tannic acid, was reduced substantially up to 67% under the alkaline conditions employed, but the reduction appeared to be greater (69-79%) at higher temperature. The loss of phytic acid was greater (27-40%) when beans were cooked in NaHCO3 than in kanwa (11-29%). The concentration of reducing sugars was decreased in all treatment groups especially under alkaline conditions. There was no evidence for the formation of lysinoalanine in any of the samples.

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. Pure cultures of Physarum polycephalum, maintained on a partially defined, soluble medium, require chick embryo extract or fetal calf serum for growth (Daniel and Rusch, 1961). This paper reports more fully the earlier finding that hematin and certain hemoproteins completely replace chick embryo extract as a growth requirement for this organism (Kelley, Daniel, and Rusch, 1960) on either a natural or synthetic medium. Only three other groups of microorganisms, Haemophilus, Trypanosomidae (Lwoff,