Effect of inhibitors and uncouplers on light-induced potential changes triggering photophobic responses

Light-energy absorption by Microcystis aeruginosa with and without gas vacuoles was observed, respectively by using an integrating sphere photometer. As far as the concentration of cell suspension of the order of 10⁶⁷ cells/ml in this work was concerned, the performance of gas vacuoles to shield incident light was most unlikely. Referring to a correlation secured by the integrating sphere photometer between light absorption and cell concentration of the suspension, a turbidostat culture of the blue-green alga demonstrated that the growth efficiency, Y_kJ defined as g cells harvested per kJ of light energy absorbed by the cells was nearly 0.004. This value of Y_kJ was almost the same as that of Spirulina platensis.Abbreviation vvm volume of air per volume of medium per min