11:45 〜 12:00
[AOS14-11] A Study of Oxygen Generation using Cyanobacteria with Sustaining and Circulation Model by Nitrite Bacteria and Nitric Bacteria Assuming the Confined Settings of Space
キーワード：宇宙居住、シアノバクテリア、亜硝酸菌、硝酸菌、酸素生成バイオーム、バイオリアクター
While Earth is currently the only planet with a sustainable environment for humans in our solar system, human spaceology, which is a study that expands human habitability to outer space, has delved into the possibility of human survivability on other planets and moons in our solar system. The International Space Station (ISS) is launched 400km above the surface of the Earth and serves as a large-scale laboratory where astronauts have been living for about six months as an experiment in human space exploration. On the ISS, water and air are as essential as on the ground. In addition to regular replenishment of water and oxygen, the life support system maintains the environment by recycling water from urine and sweat, removing carbon dioxide, and generating oxygen through the electrolysis of recycled water. Moreover, the Artemis program is an ongoing project aiming to achieve manned space exploration and long-term habitation on the Moon and eventually Mars. The generation of drinking water and oxygen for respiration using lunar water resources will be studied on-site in this program.
On the other hand, Yamashiki et al. anticipate human migration to the Moon and Mars, which could become a reality in the latter half of the 21st century. To achieve this, they defined Earth’s ecosystem and identified the elements that make up the "core-biome," which consists of the minimum elements necessary for sustaining life on other planets. In this concept, they developed the goal of enabling space migration through the integration of three core concepts: defining “core-biome” as the minimum selected biome required for migration, identifying “core technologies”, and establishing a “core society”. As one of the core technologies, the operation of life support systems is essential for human survival in space, requiring oxygen-containing air, carbon dioxide removal, water recycling, and a food supply.
Currently, on the ISS, oxygen generation, carbon dioxide removal, and water recycling are carried out using electrochemical reactions by specialized instruments. However, reusable materials such as carbon dioxide and components in urine are removed without recycling valuable elements. Therefore, developing new technologies that utilize these materials in a selected biome is essential for sustainable settlement in space and for the establishment of human spaceology.
Previous studies have explored using cyanobacteria as a biological system for oxygen generation. However, the culture medium needed to be periodically supplemented to maintain the required nutrient levels, preventing the establishment of a self-sustaining system in a confined setting. Nitrate and phosphate are essential for sustaining cyanobacteria, and within a closed environment including humans, urine-derived components may be utilized as a nutrient source.
This study aims to establish a stable system for oxygen generation in a confined setting with a selected biome by integrating cyanobacteria for oxygen production and carbon dioxide removal, alongside nutrient recycling using nitrate bacteria with urease activity and nitrite bacteria. We present a selected species, a circulation model for nutrition, and preliminary results demonstrating the conversion of urine into nitrate through co-culturing a selected species. Additionally, we provide experimental results confirming oxygen generation using cyanobacteria in confined settings with bioreactors.
On the other hand, Yamashiki et al. anticipate human migration to the Moon and Mars, which could become a reality in the latter half of the 21st century. To achieve this, they defined Earth’s ecosystem and identified the elements that make up the "core-biome," which consists of the minimum elements necessary for sustaining life on other planets. In this concept, they developed the goal of enabling space migration through the integration of three core concepts: defining “core-biome” as the minimum selected biome required for migration, identifying “core technologies”, and establishing a “core society”. As one of the core technologies, the operation of life support systems is essential for human survival in space, requiring oxygen-containing air, carbon dioxide removal, water recycling, and a food supply.
Currently, on the ISS, oxygen generation, carbon dioxide removal, and water recycling are carried out using electrochemical reactions by specialized instruments. However, reusable materials such as carbon dioxide and components in urine are removed without recycling valuable elements. Therefore, developing new technologies that utilize these materials in a selected biome is essential for sustainable settlement in space and for the establishment of human spaceology.
Previous studies have explored using cyanobacteria as a biological system for oxygen generation. However, the culture medium needed to be periodically supplemented to maintain the required nutrient levels, preventing the establishment of a self-sustaining system in a confined setting. Nitrate and phosphate are essential for sustaining cyanobacteria, and within a closed environment including humans, urine-derived components may be utilized as a nutrient source.
This study aims to establish a stable system for oxygen generation in a confined setting with a selected biome by integrating cyanobacteria for oxygen production and carbon dioxide removal, alongside nutrient recycling using nitrate bacteria with urease activity and nitrite bacteria. We present a selected species, a circulation model for nutrition, and preliminary results demonstrating the conversion of urine into nitrate through co-culturing a selected species. Additionally, we provide experimental results confirming oxygen generation using cyanobacteria in confined settings with bioreactors.