Chlorella pyrenoidosa a species of fresh water green algae can play a key role in space travel to get rid of CO2 and recycle other body wastes. The algae multiply rapidly and utilize the CO2 and liberate O2 during photosynthesis. It decomposes human urine and feces to get N2 for protein synthesis.
In long-range space exploration, scientists have turned to Chlorella or similar algae to use it as portable oxygen generators and food sources.