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Aus dem Kulturmedium auxotropher Mutanten von S. typhimurium und E. coli, deren genetischer Block innerhalb der Tryptophan-Synthese zwischen Anthranilsäure und Indol liegt, wurde ein im UV-Licht blau fluoreszierendes Indol-Derivat isoliert und als Indol-3-glycerin identifiziert. Bei einer Mutante von S. typhimurium, welche in Gegenwart von radioaktivem anorganischem Phosphat gezüchtet worden war, ließ sich nach Lyse der Bakterien ein im UV-Licht ebenfalls blau fluoreszierendes, stark radioaktives Indol-Derivat nachweisen. Die Kombination dieser Befunde mit Ergebnissen von YANOFSKY führt zu dem Schluß, daß bei der biochemischen Tryptophan-Synthese von E. coli und S. typhimurium das Zwischenprodukt Indol-3-glycerin-phosphorsäureester auftritt, welches entphosphoryliert als Indol-3-glycerin im Medium erscheint. Als Modellsubstanzen synthetisierte Anthranilide von Glykolaldehyd, D-Ribose und D-Glucose erwiesen sich im Wachstumstest an S. typhimurium-Mutanten als unwirksam.

Measurements are reported on the stability of planar, npn silicon transistors with and without a phosphosilicate glass layer over the SiO2 passivation layer. The phosphosilicate layer forms during the emitter diffusion from a P2O5 source, and the data show that, to insure stability, it must not be removed in subsequent processing steps. The units tested were of conventional geometry except for a gate electrode over the base region, which provided additional information on the surface conditionT. he transistors were subjected to temperatures of 150° and 200°C with either gate-bias or junction reverse-bias. Production transistors, without gates, which had failed on life test were shown to have no phosphosilicate layer because it had been removed by excessive etching during fabrication. Additional evidence for the stabilization by P2O5 has been obtained using metal-oxide-silicon capacitors with and without P2O5 treatment of the SiO2 layer. Both dc conduction through the insulator and stability of the capacitance-voltage characteristic were measured. These experiments suggest that the transistor degradation with unstabilized SiO2 is caused by an accumulation of positive space-charge in the silicon-dioxide. This charge accumulates when an electric field (directed toward the silicon) is applied to the SiO2 at temperatures in the range of 150°C.

The dark color occasionally found in crude solvent-extracted oils from a new high-yield brown striped safflower variety originates from colorless precursors in the kernel and precursors in the hull. The precursors from the hull and the pigments formed upon heating from hull and kernel precursors are only partially removed by refining and bleaching if they are present in substantial amounts. The pigment precursors extracted from the kernels are completely removed by precipitation with water or refining. Although substantially more hull and kernel precursors are found in oil from the brown striped safflower variety, the oil can be produced in a spectrographic quality comparable to that of commercial oil if the crude extracted oil is not heated above 100 C, and if extracted and press oils are jointly refined.

Studies on phosphatides from several safflower varieties show the following five major results. The total phosphatide contents of the various safflower seeds are quite similar (0.48% for a commercial and 0.58% for a brown-striped variety). The same three major and one minor phosphatides were present in all varieties: phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI) and phosphatidyl serine (PS). The amounts of these lipids present in the crude phosphatide mixture were quite similar in all varieties tested (}36% for PC, }15% for PE, }23% for PI, and less than 2% for PS). The fatty acid composition of the phosphatides of UC-1 high oleic safflower is very different from that of the other varieties, but it reflects the composition of the corresponding oil triglycerides as far as the major acid is concerned. All other safflower seed phosphatides investigated have linoleic acid as the major fatty acid constituent. A simple and very sensitive color test has been found which can differentiate phosphatides of the high linoleic from the high oleic type.

A batch peeler using time-regulated, high-pressure steam is briefly described. Use of the equipment with sweet potatoes [Ipomoea batatas (L.) Lam.] avoided explosion of the roots encountered with conventional high-pressure steam peelers and resulted in effective peeling with minimal enzymatic discoloration of the product.

Größere als zur Erlangung maximaler Populationsdichte notwendige Tryptophan-Mengen wirken bei Tryptophan-Mangelmutanten hemmend auf die Akkumulation von Metaboliten. Da D- und L-Tryptophan gleich stark hemmend wirken, D-Tryptophan aber nicht verwertet werden kann, werden Tryptophan-Mangelmutanten zur Erlangung optimaler Mengen des Akkumulations-Produktes zweckmäßigerweise nur mit L-Tryptophan gezüchtet. Maximale Akkumulation entsteht bei einem Tryptophan-Gehalt von 0,5 bis 1 γ pro ml Nährmedium. Elf verschiedene Mutanten von Salmonella typhimurium und Escherichia coli werden quantitativ hinsichtlich ihrer Fähigkeit zur Akkumulation von Indol verglichen.

The dark color found in extracted oils from two new thin-hull safflower varieties is formed from a colorless precursor or precursors, which for convenience will be considered a single precursor. This precursor is extracted into the oil from the kernel portion of the seed with hot hexane. It condenses to a dark pigment, if heated for prolonged times in excess of 100C, and was found in varying amounts in hot extracted oils of pigmentless, brown-striped, and commercially grown Gila varieties. The color precursor can be removed from the oil by extraction with water or by alkali-refining. The dark pigment can be removed by treatment with dilute alkaline peroxide. Oil, free of pigment and pigment precursor, can be obtained if the press-cake or whole cracked seeds are extracted with hexane at room temperature.

AN investigation has been made concerning the degree to which various concentrations of boric acid inhibit the growth of three soil micro-organisms and the extent to which this inhibition may be reversed.

1. Tests of the olfactory mucosa of rabbits by five different methods indicate that cholinesterase is probably not present in any of the cells of this tissue. 2. Alkaline phosphatase and phosphamidase were not found in the olfactory receptors. 3. Acid phosphatase and sulfhydryl groups were found to be present in the receptors, and the presence of cytochrome oxidase was demonstrated in gross sections of turbinate tissue.