Photoinhibition and the availability of inorganic carbon restrict photosynthesis by surface blooms of cyanobacteria

摘要

When buoyant cyanobacteria form a surface bloom, they may obtain inorganic carbon from the water and the atmosphere. In this study, artificial blooms of cyanobacteria were exposed to different concentrations of CO_2 in the atmosphere and HCO_3~- in the water. The conditions and photosynthetic activity within the bloom were measured with microelectrodes sensing O_2, pH, and light. Net rates of photosynthesis increased with the concentration of CO_2 in the atmosphere (air = 350 ppm).