Among the items necessary for life support in a closed ecological system designed for space travel one may list oxygen, water, food, and energy. The production of oxygen for breathing has apparently been claimed by photosynthologists, and the production of drinking water by a variety of engineers. Acceptable food for the space man, while it should be within the province of food technology, has been almost totally neglected by this and other groups. Considerations of energy in closed ecosystems have been made to some extent by everyone. Both speculations and calculations outlining the character and placement of the probable members of closed life support systems have been made repeatedly. Myers (1960), Bowman (1953), Konecci (1959), Brockman et al., (1958), and Tischer (1960) are examples. More recently attention has turned to a consideration of methods suitable for the modification and degradation of human wastes for use by subsequent members of the system. Chapman (1960) has employed an activated sludge process to reduce the COD of human wastes by as much as 90% in 24 hours of treatment. Others have used more or less conventional waste treatment methods employing bacteria and algae while Tischer (1962) has used thermophilic bacteria, hypochlorite digestion, and electrochemical degradation. Research in this laboratory has provided information on several microorganisms and methods which might find use in the ultimate closed ecology. It is the purpose of this discussion to describe some of these and to comment on their utility.