Proliferation and Survival Analysis of Rhizosphere Soil Bacteria in a New Mars Soil Simulant Under Mars Simulated Conditions

Abstract

Behzad Qureshi

The growth of plants on Mars has a significant importance ranging from being an essential food source to oxygen production and raw material for manufacturing purposes, for early Mars colonists. Rhizosphere-dwelling bacteria perform key functions in the growth and development of plants. In this study, the growth and survival of rhizosphere soil bacteria were examined for a period of 7 days in Khyber Pakhtunkhwa Red Mountainous Soil (KP-Mars-1), representing Mars soil simulant. KP-Mars-1 is our identified Mars soil simulant, which we characterized and refined. It exhibits similar elemental composition as Mars soil and can potentially be used as a Mars soil simulant. The simulated Mars conditions provided in this study for the analysis of bacterial growth and survival included; a temperature range of + 24 °C and – 20 °C, low soil moisture content, anaerobic atmosphere (carbon dioxide dominant), and UV-C ionization radiation (200nm – 280nm). A nutrient broth culture of 3.6 mL was inoculated in 5g of KP-Mars-1. The growth and survival of rhizosphere soil bacteria were analyzed at 1, 3 & 7 day intervals. Rhizosphere soil bacteria were able to survive all of the provided Mars conditions. A significant number of bacterial cells died in Mars simulated temperature and UV-C radiations. A significant growth was observed only in anaerobic (carbon dioxide dominant) conditions.