Effect of auxin precursors and chemical analogues on the growth and chemical composition in Chlorella pyrenoidosa Chick

In this paper the authors present studies on the effect of auxin precursors and chemical analogues on the growth and biochemical composition in Chlorella pyrenoidosa (Chlorophyceae). Among auxin precursors tryptamine exhibited slightly higher stimulative activity in regard to fresh and dry weight, mineral substances, chlorophylls, carotenoids, monosaccharides (aldohexoses) and water-soluble proteins content in Ch. pyrenoidosa cells as compared to anthranilic acid. Among auxin analogues used phenoxyacetic acid and naphthyl-3-acetic acid had the strongest stimulative effect of the above-mentioned parameters. Their activity was significantly higher than that of auxin precursors. The activity of naphthyl-3-sulphonic acid was slightly lower than that of tryptamine, whereas the stimulation by 2,4-dichlorophenoxyacetic acid was similar to that of anthranilic acid. In Ch. pyrenoidosa cells 2,4-dichlorophenoxyacetic acid and naphthyl-3-sulphonic reached their maximum activity at the latest (between the 15th or 16th day) of the culturing, whereas tryptamine, phenylacetic acid, naphthyl-3-acetic acid and indolyl-3-acetic acid - at the earliest (between the 8th or 12th) day.