The C : N : P Ratio of Microcystis and Anabaena (Blue-Green Algae) and its Importance for Nutrient Regeneration by Aerobic Decomposition

Abstract

Microcystis and Anabaena were collected from their natural environments and decomposed under aerobic conditions in the laboratory. They had low C : N : P ratios (74 : 13 : 1 for Microcystis and 58 : 8 : 1 for Anabaena, by weight) and released both dissolved inorganic nitrogen (DIN) and phosphorus (DIP) by decomposition. Thus, it was demonstrated that the phytoplankton with low C : N : P ratio release both DIN and DIP by decomposition, whereas those with high C : N : P ratio (e.g., 200 : 20 : 1 in summer), like the phytoplankton in the euphotic zone of Lake Biwa during the stagnation period, release only DIN (TEZUKA, 1985b, 1986).