ATP levels in algal cells as influenced by environmental conditions

摘要

The cellular content of adenosine triphosphate (ATP) relative to cell size and cellular organic carbon has been investigated in 30 different algal cultures representing 7 phyla. During exponential growth in batch culture, cellular contents of ATP remained at fairly uniform levels in all these unicellular algae and averaged 0.35of the cellular organic carbon content. During extreme nitrogen or phosphorus deficiency the cellular levels of ATP decreased to 20–50of that found in exponentially-growing cells, but these percentages may be low due to detrital carbon in the senescent cultures.The steady state levels of ATP in cells were similar in light or in dark, although ATP concentrations fluctuated for a few minutes upon any sudden change in light conditions. When the light was turned on there was a rapid increase in ATP levels, followed by a slow decrease; when the light was turned off, there was a rapid fall in cellular ATP levels, which then rose within a few minutes to achieve the steady state concentration. The cellular concentrations of ATP in these algae and in other microbial groups are discussed relative to studies where ATP determinations are used to estimate microbial biomas