The investigation of kinetic growth of Chlorella vulgaris cells by the method of integral and dynamic light scattering

Abstract

Laboratory measurements of light scattering on axenic cultures of the unicellular alga Chlorella vulgaris confirm multilevel light scattering by the cell (i.e. both by the outer cell membrane and the internal structure of the cell, as well as by its molecular structure). The technique of dynamic light scattering and analysis by the regulation method suggest that the light scattering phenomena is affected by particles of sizes corresponding either to the overall dimensions of the cell or to the dimensions of its internal structure. A correlation was found between the suggested sizes and the stage of physiological evolution of the culture. Three well‐known stages (adaptation, logarithmic and stationary growth) can be recognized easily in changes observed in the size distribution of the scattering centers as measured by the dynamic light scattering technique and in the shape changes of elements of the scattering matrix. The occurrence of cells containing large internal structure elements, such as autospores, affect elements of the scattering matrix, suggesting that cell structure should be taken into account as a scattering system producing rotatory polarization of the scattered light.