Reinigung der Proteinase aus Nepenthes-Kannensaft

Zusammenfassung Der sterile Kannensaft von drei Nepenthes-Arten wurde chromatographisch und elektrophoretisch untersucht. Bei Auftrennungen durch Adsorptionschromatographie an Ecteola-Cellulose und durch Elektrophorese wurde jeweils nur eine proteolytische Enzymfraktion erhalten. In gereinigten, kohlenhydratfreien Enzymfraktionen wurde ein pH-Optimum bei 2,2 und ein Temperaturoptimum bei 50°C gefunden.

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Purification of the proteinase from Nepenthes pitcher secretion

Summary The proteolytic enzymes from the sterile secretion of the pitchers of 3 Nepenthes species were purified to electrophoretic homogenity by chromatography on Ecteola cellulose. The properties of the purified enzymes were investigated.

     

Physiology of Morphactins: Effect on Gravi- and Photo-response

Plant roots and shoots respond to gravity and light source in a definite way. Thus, there are typical geotropic and phototropic responses for roots and shoots. When seedlings were grown in presence of morphactins, IT 3233 or IT 3456, on a vertical or a horizontal plane, the roots and shoots lost the capacity to respond to gravity or to unilateral light source. This was true for both monocots and dicots. This suggests that basic mechanism (s) of the two tropic responses are the same in the roots and shoots of the two plant groups. The site(s) of action of morphactins is unknown. The reaction (s) controlling geotropism and phototropism may be closely related as morphactins affected both geotropic and phototropic response of the same organ. Indoleacetic acid and gibberellic acid per se did not modify the effect of morphaclins on geotropism. Growth retardation effect of morphactins appears to be controlled by another mechanism.     

Production of Aflatoxins B1 and G1 by Aspergillus flavus in a Semisynthetic Medium

Isolates of Aspergillus flavus produced 0.2 to 63 mg of aflatoxins B(1) and G(1) per 100 ml in a nutrient solution consisting of 20% sucrose and 2% yeast extract. Various factors influencing the fermentation were studied. The maximal amount of toxin was produced by ATCC culture 15548 in 1-liter flasks containing 100 ml of medium incubated as stationary cultures for 6 days at 25 C.