Effects of Metabolic Inhibitors on the Calcification of a Freshwater Green Alga, Gloeotaenium loitlesbergarianum Hansgirg. 1. Effects of Some Photosynthetic and Respiratory Inhibitors

The effect of a number of metabolic inhibitors on the calcificationof Gloeotaenium loitlesbergarianum Hansgirg, a freshwater greenalga, was studied. The inhibitors used were methylamine, trimethylamine,mercuric chloride, imidazole, fluoride, arsenate, atrazine,DCMU and dinitrophenol. The effects of these inhibitors showthat transport, or stimulation of respiratory carbon dioxideevolution inhibits calcification. Calcification in Gloeotaeniumis, at least partly, due to a local rise in pH as a result ofphotosynthetic carbon dioxide assimilation. There is also someevidence that, apart from its role in carbon dioxide assimilation,photosynthesis supplies the additional energy needed for calcification. Calcification, Gloeotaenium loitlesbergarianum Hansgirg, green algae, Chlorophyceae, metabolic inhibitors, photosynthesis, respiration