Observations on the Anaerobic Respiration of Potato Tubers

Studies on the Dormancy and Sprouting of Potatoes

“…There is broad agreement between published values for the percentage of COg at different temperatures in the intercellular atmosphere, even though these values were determined on a number of varieties at different times and places (see, for example, Devaux, 1890Devaux, , 1891Kidd, 1938;Boswell & Whiting, 1940;Burton, 1950). In general, the concentration is at a minimum at about 5-10° C, rising because of increased respiration both at higher and lower temperatures.…”

“…The pH values given by Small, even for sap in equilibrium with a C02-free atmosphere, were however much lower (pH 5-7) than those determined on Arran Consul tubers in the course of the present work. Boswell & Whiting (1940) determined the bound CO2 in thin slices of potato tuber tissue in equilibrium with known pressures of CO2 in the atmosphere. The bound CO2 was liberated by the addition of 10% H2SO4-a method which may be regarded as the most reliable for this purpose.…”

“…The inverse relationship bet^veen the partial pressure in the intercellular space and the proportion of ' bound' CO2 present is thus even more marked than usual. When a wider range of partial pressure of CO2 has been studied without any accompanying temperature changes (Kidd, 1938;Boswell & Whiting, 1940) an increased partial pressure has been found to cause an increase in the bound CO2.…”

Respiration The Pasteur Effect in Plants

“…P. > 1 and provided that the NR arises metabolically, "it may be inferred, without further consideration of metabolic (15), and if the extrapolation method of Blackman is used. There is therefore good evidence for the existence of the P. E. in yeast and some 17 species of higher plants.…”

“…For the Bramley seedling the fermentation is only 85 per cent alcoholic, the excess NR being labelled NRRES. If this component of the NR is neglected, as possibly arising from non metabolic sources(15), the ratio carbon loss in nitrogen/carbon loss in air is 3.6; if the NRRES is considered as coming from carbohydrate, the figure is 4.1. Thus, this variety of apple is shown to have a marked Pasteur effect by determination of alcohol and its accompanying NR only.…”