EVALUATING MICROGRAVITY EFFECTS ON MICP PERFORMANCE FOR LUNAR IN-SITU RESOURCE UTILIZATION

Abstract

The loose regolith on the lunar surface presents significant challenges for base construction. Microbially induced carbonate precipitation (MICP) has been proposed as a promising method for enhancing lunar regolith strength. However, the microgravity environment may affect microbial growth and mineralization efficiency, potentially influencing the feasibility of MICP-based stabilization. This study investigated the microbial growth behavior, urease activity, and microstructural changes of Lederbergia lenta (RII-2) under different culture medium and gravitational conditions. Experiments were conducted using NH₄-YE, R2A, and R2A-Urea medium to assess bacterial performance over 168 h. The results indicate that RII-2 exhibited the highest OD₆₀₀ value in R2A-Urea medium, significantly surpassing NH₄-YE and R2A. Urease activity tests revealed that R2A-Urea medium exhibited the highest overall enzymatic activity among the three media. Under microgravity conditions, RII-2 showed a 40% increase in OD₆₀₀ and a 22-28% decline in urease activity compared to normal gravity. These findings suggest that experimental conditions affect bacterial growth and enzymatic function, which may impact the efficiency of regolith stabilization by MICP in space environments.