Problem of reproduction of food protein by autotrophic organisms in extraterrestrial conditions.

To supply a man during his prolonged stay in extraterrestrial space with dietary protein by storing it in space vehicles seems to be impractical. Protein reproduction could be realized at present only by biosynthesis, which is possible with the autotrophic organisms and is the most economic, universal and therefore quite possible for use in life-support systems. In the paper, experimental results are presented on the biological value of single-celled algae proteins. The results obtained suggested that algae biomass in human rations could not be used in quantities needed for turnover of the components of the space-cabin atmosphere. The main obstacles lie in a hard broken algae shell, a large quantity of pigment, "allergization" of persons with biomass included in their rations, lack of some aminoacids in the protein, as well as man's psychological negativism to algae as a food product. Use of single-celled algae as a food source in the future will depend on improvement of its technological and biological management. A possible use of hydrogen-reducing bacteria as a biological dietary protein product is discussed.