Scheffrahn H
Institut für chemische Pflanzenphysiologie der Universität Tübingen, Tübingen, Deutschland.
Planta. 1966 Jun;71(2):140-59. doi: 10.1007/BF00390134.
The role of folic acid in metabolism was studied in mass cultures of Chlorella pyrenoidosa, especially with respect to its possible participation in early stages of photosynthetic CO2-fixation. Sulfonamides (sulfanilamide, sulfathiazole) were used as specific antimetabolites in the biosynthesis of folic acid.After 24 hours the number of cell divisions was much more diminished than the pigment and nucleic acid content of the cells. Significant inhibition of mass production did not occur before 48 hours. This difference in the sensitivity of cell division and mass production towards the antimetabolite leads to a definite increase in cell size.Antimetabolites administered together with (10(-6) mol/l) p-aminobenzoic acid or (10(-5) mol/l) folic acid cause no inhibition.The harmful effect of the sulfonamide is strictly reversible; the speed of recovery depends on the p-aminobenzoic acid concentration. (14)C-Fixation experiments gave no evidence for the participation of folic acid enzymes in primary processes of photosynthetic carbon uptake. The decline of the fixation rate may be interpreted as a secondary effect on the enzyme apparatus necessary for photosynthesis.The enormous increase of the sugar content in the individual cells indicates a general disturbance of the metabolism.
在小球藻的大规模培养中研究了叶酸在代谢中的作用，特别是关于其可能参与光合二氧化碳固定的早期阶段。磺胺类药物（磺胺、磺胺噻唑）被用作叶酸生物合成中的特异性抗代谢物。24小时后，细胞分裂的数量比细胞的色素和核酸含量减少得更多。在48小时之前未发生对大规模生产的显著抑制。细胞分裂和大规模生产对抗代谢物敏感性的这种差异导致细胞大小有一定增加。与（10^(-6)摩尔/升）对氨基苯甲酸或（10^(-5)摩尔/升）叶酸一起施用抗代谢物不会产生抑制作用。磺胺类药物的有害作用是完全可逆的；恢复速度取决于对氨基苯甲酸的浓度。（14）C固定实验没有证据表明叶酸酶参与光合碳吸收的初级过程。固定率的下降可以解释为对光合作用所需酶装置的次级影响。单个细胞中糖含量的大幅增加表明代谢普遍受到干扰。
