ABSTRACT
There are no exchanges of energy and matter between completely closed ecosystem and the surrounding environment. Engineering life-support ecosystems in space stations, submarines, polar stations, and artificial research ecosystems are “materially closed” but have a supply of energy from chemical, electric, or nuclear fuel, or from sunlight. When humans, animals, and plants are living in a closed ecosystem, their wastes are usually converted to food and water through microbial degradation. Then, microbial and plant assimilation of inorganics, organics, and carbon dioxide are used for the regeneration of food. Production of oxygen from water could be due to oxygenic phototrophy or electrolysis of water. A tutorial with solutions is added to this chapter.
