Effects of some nutrient elements on heterocyst differentiation in Anabaena and Cylindrospermum Sp.

The effects of some major and trace elements are investigated on the differentiation of hetero-cysts in Anabaena and Cylindrospermum. The hsterocysts were differentiated in deionized water and in medium lacking any of the major or trace elements of Allen and Anion’s medium. The differences were significant in Cylindrospermum sp. except in the presence of molybdenum trioxide (MoO₃) implying that it played a crucial role. Interestingly enough, no such significant differences were noticed in Anabaena sp.