Chlorella vulgaris strain C1 was grown in laboratory under autotrophic and mixotrophic conditions. Cellular division rates increased in cultures supplied with either acetate or glucose. As a direct result respiratory activity was enhanced in those cells, most pronounced in the presence of acetate. Glucose and acetate had opposed effects on the photosynthetic activity of the cells. Cells grown in the presence of acetate had a 3-fold decrease in pigment contents. Since this was mostly expressed in decreased light utilization efficiency of the cells, we conclude that fewer light harvesting antennae were synthesised. Cells grown with glucose retain high pigment contents and photosynthetic activity of the cells was strongly enhanced. It was observed that even though organic matter may support algal growth in oxidation ponds, at the same time one may expect a much stronger oxygen demand accompanied by a reduced photosynthetic potential. This must be considered a burden on the wastewater treatment operation requiring countermeasures to be taken.

This content is only available as a PDF.
You do not currently have access to this content.