Abstract

Photosynthetic microorganisms, including cyanobacteria and microalgae, have garnered increasing attention for their bio-stimulant effects on plant growth and development. These microorganisms possess unique capabilities to fix atmospheric carbon dioxide, produce organic compounds, and enhance nutrient availability in soil or hydroponic systems. In this review, we provide an overview of the bio-stimulant effects of photosynthetic microorganisms on plants and explore their potential applications for space agriculture.

Photosynthetic microorganisms can promote plant growth through various mechanisms, including nitrogen fixation, phosphorus solubilization, production of plant growth-promoting substances (e.g., phytohormones, vitamins), and improvement of soil structure. Furthermore, symbiotic associations between photosynthetic microorganisms and plants can enhance stress tolerance, water use efficiency, and nutrient uptake in challenging environments. In the context of space agriculture, the utilization of photosynthetic microorganisms offers several advantages for sustainable food production in extraterrestrial habitats. These microorganisms can serve as biological factories for oxygen production, carbon sequestration, and biomass generation, providing essential resources for closed-loop life support systems. Additionally, their ability to thrive in low-gravity environments and utilize non-traditional substrates (e.g., wastewater, atmospheric gases) makes them promising candidates for bioregenerative life support systems aboard space stations or extraterrestrial colonies.

However, several challenges and considerations must be addressed to realize the full potential of photosynthetic microorganisms in space agriculture, including optimization of cultivation methods, selection of suitable strains, and integration of microbial communities into controlled environment systems. Furthermore, the long-term effects of microgravity and space radiation on photosynthetic microorganisms and their interactions with plants require further investigation to ensure the success of space-based agricultural systems. In summary, harnessing the biostimulant effects of photosynthetic microorganisms holds great promise for advancing space agriculture and enabling sustainable food production beyond Earth. By leveraging the unique capabilities of these microorganisms, we can overcome the challenges of extraterrestrial agriculture and pave the way for human exploration and colonization of space.