Energy transduction in photosynthetic bacteria. VIII. Activation of the energy-transducing ATPase by inorganic phosphate

ATPase activity and ATP-induced energization of photosynthetic membranes from Rhodopseudomonas capsulata are stimulated by phosphate; the maximum stimulatory effect occurs at a concentration between 1 and 2 mM.The sensitivity of the ATPase to oligomycin increases in the presence of phosphate since all the P_i-stimulated activity is inhibited by this antibiotic. Aurovertin, which has no effect on ATPase in the absence of phosphate, inhibits completely the activity elicited by this anion.The addition of P_i induces a substantial increase in the V of ATPase activity without changing the affinity of the enzyme for ATP or ADP.Arsenate, at the same concentrations, produces effects very similar to those of phosphate. The stimulation by arsenate of the transfer of energy from ATP to the membrane suggests a non-hydrolytic role of this anion as a modifier of the ATPase activity.     

Plasmolyse und Permeabilität

Ohne Zusammenfassung Mit 3 Textfiguren     

An improved breeding method for solitarious locusts

In order to unravel the physiological, endocrine, and behavioral differences between gregarious and solitarious forms of the desert locust, Schistocerca gregaria (Forsk.) (Orthoptera, Acrididae), a constant supply of rather large numbers of solitary individuals has to be guaranteed. This represents a bottleneck, mainly because of the intensity of the labor involved and limited laboratory accommodation. The method we describe here substantially reduces the space and manpower needed. The survival rate we obtained in the solitarised population was relatively high, reaching about 55%. The optimal rearing temperature proved to be 32–36 °C. Cabbage leaves and oat flakes sufficed for feeding all year round. Special racks have been designed that enable high density stacking and easy handling. The solitarisation process was monitored over ten consecutive generations. Changes in morphometrics, eye stripes, color, and behavior were recorded, of which only morphometrics, temperature related development, and mortality are discussed. A shift towards the solitarious phase was recorded, with clear differences between gregarious, 1^st generation and 7^th to 10^th generation solitarious locusts.