METABOLITE RECYCLING IN A CLOSED BIOLOGICAL LIFE SUPPORT SYSTEM: SYSTEMIC REFINEMENTS AND ACQUISITION OF RADIORESISTANCE OF ITS KEY AGENT SPIRULINA PLATENSIS

摘要

However, given the very vital tasks conferred to a prokaryotic microorganism, it is desirable to minimize the danger of sterilization of the blue-algae by long-term exposure to ionizing radiation and insufficient shielding. Therefore, an empirical "training-effect" confirmed several times independently in literature, is brought to attention and proposed for adapation to S. platensis: Repeated cycles of irradiation and subsequent recovery of the surviving fraction showed to progressively induce resistance to ionizing radiation such as gamma- and UV-radiation by up to 20-fold in E. coli, Bacillus pumilus and Salmonella typhimurium. In first experiments, S.p. proved to tolerate irradiation of 660Gy within 3 hours. In view of that, its suitability for space flight in relation to galactic rays is evaluated.