| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1092-1 | ||||
Resumo:The weathered granitic-pegmatitic masses exposed to open-air conditions in Perus (São Paulo, Brazil) represent abundant reservoirs of uranium-rich minerals, creating a unique natural environment exposed to intensified local radiation from both radioactive decay and solar ultraviolet radiation. This distinct habitat sustains a highly diverse microbial population, evoking significant interest from an astrobiological standpoint. Among the exceptional radioresistant bacteria, Deinococcus radiodurans has emerged as a well-established model organism, thriving under extreme conditions. In this study, we investigate the radiation resistance of four bacterial strains (two Nocardioides sp., Sphingomonas sp., and Pseudarthrobacter sp.) isolated from distinct uraniferous minerals (Meta-Autunite and Uraniferous Opal) subjecting them to varying doses of UV-B, UV-C, Environmental UV (UV-A + UV-B), and Gamma radiation. Comparative evaluation of their performance against the model organism D. radiodurans was carried out, revealing intriguing findings. Survival curves were generated for each microorganism under UV-C, UV-B, and Environmental UV exposures, initially displaying comparable outcomes with D. radiodurans. Remarkably, the most resilient isolate, Nocardioides sp., exhibited resistance comparable to the model organism in UV-C radiation resistance tests and superior resistance in UV-B and Environmental UV resistance tests. However, in Gamma radiation tests, all isolates demonstrated diminished performance compared to D. radiodurans. This investigation provides valuable insights into the radiation tolerance capacities of microbial communities thriving in uranium-rich environments, highlighting the significance of Nocardioides sp. as a promising candidate for further astrobiological investigations. Palavras-chave: Astrobiology, Radiation resistance, Ultraviolet Radiation, Ionizing Radiation, Environmental Microbiology Agência de fomento:CAPES | |||||