Melafen action on the growth and physiological parameters of phototrophic and heterotrophic microorganisms

Abstract

Melafen, a synthetic plant growth regulator, stimulates the growth of periodic cultures of cyanobacteria Anacystis nidulans and Anabaena variabilis and green microalgae Chlorella vulgaris by 30–80%, when applied within the concentration range of 10−8–10−6 M. If the melafen concentration lies out of this range, it is either ineffective or inhibits the growth of these microorganisms. The growth and development of green microalgae Dunaliella maritima are stimulated, and the cell growth of heterotrophic bacteria Pseudomonas diminuta is inhibited in a wide range of the increased melafen concentrations. This agent also stimulates the growth of dialyzed phototrophic cultures and the formation of heterocysts and vegetative cells in the filaments of Anabaena variabilis, increases the redox potential of a cultivation medium, and reduces a carbohydrate excretion from the cells of phototrophic microorganisms. It is supposed that melafen activates the processes of photosynthesis and atmospheric nitrogen fixation.