Análise de adaptação da levedura Rhodotorula dairenensis em ambientes extremos: implicações astrobiológicas em ambientes de alta salinidade e alta pressão

Abstract

Astrobiology is a recent science that studies the origin, evolution and future of life on planet Earth and beyond. These studies use microorganisms considered extremotolerant or extremophiles, which have adaptation mechanisms to environments where living conditions are considered hostile for the majority of living beings. The Diamantina region, in Minas Gerais, is considered analogous to Mars due to the fact that it is an arid and hot environment. Furthermore, the region has sedimentary deposits indicating that the site was an inlet of the sea 500,000 years ago. Therefore, the objective of this work was to evaluate the halotolerant capacity and resistance to high temperatures of the yeast Rhodotorula dairenensis that was collected in Diamantina. The yeast samples were subjected, in duplicate, to saline media with sodium chloride concentrations equal to 3%, 5%, 7% and 10%. For temperature tests, samples were subjected, in duplicate, to temperatures of 30ºC, 40ºC and 45ºC for 72 hours in a shaker. To quantify the growth of microorganisms, a spectrophotometric analysis was carried out using a standard growth curve. The analyzes demonstrated that the yeast Rhodotorula dairenensis has halotolerant potential, resisting high saline concentrations and low resistance to temperatures above 40ºC. The results obtained indicate that the yeast has potential for astrobiological studies.