Effect of the state of zero gravity on active cultures of unicellular algae

The primary effects of zero gravity on the growth, development, and prolife ration of algal cells, as well as cell interactions within the populations, were studied on board the orbital station Salyut-6 and Mir and the Kosmos series of biosatellites. The biological functions of gravitation are among the major problems immediately related to developing a life-support system to operate under space-flight conditions. In the context of this problem, a closed ecological system (water microcosm) was constructed and the effects of space-flight factors on the system as a whole and on the particular org anisms (unicellular algae, bacteria, and fish) incorporated into this syste m were studied. The growth, development, and proliferation in active cultur es of unicellular algae (in axenic culture or as part of an algae-bacteria- fish system) proceeded properly under zero gravity; and the space-flight fa ctors did not affect any indices of algal productivity.