The responses of an anaerobic microorganism, Yersinia intermedia MASE-LG-1 to individual and combined simulated Martian stresses

Abstract

The limits of life of aerobic microorganisms are well understood, but the responses of anaerobic microorganisms to individual and combined extreme stressors are less well known. Motivated by an interest in understanding the survivability of anaerobic microorganisms under Martian conditions, we investigated the responses of a new isolate, Yersinia intermedia MASE-LG-1 to individual and combined stresses associated with the Martian surface. This organism belongs to an adaptable and persistent genus of anaerobic microorganisms found in many environments worldwide. The effects of desiccation, low pressure, ionizing radiation, varying temperature, osmotic pressure, and oxidizing chemical compounds were investigated. The strain showed a high tolerance to desiccation, with a decline of survivability by four orders of magnitude during a storage time of 85 days. Exposure to X-rays resulted in dose-dependent inactivation for exposure up to 600 Gy while applied doses above 750 Gy led to complete inactivation. The effects of the combination of desiccation and irradiation were additive and the survivability was influenced by the order in which they were imposed. Ionizing irradiation and subsequent desiccation was more deleterious than vice versa. By contrast, the presence of perchlorates was not found to significantly affect the survival of the Yersinia strain after ionizing radiation. These data show that the organism has the capacity to survive and grow in physical and chemical stresses, imposed individually or in combination that are associated with Martian environment. Eventually it lost its viability showing that many of the most adaptable anaerobic organisms on Earth would be killed on Mars today.

Survivability of Soil and Permafrost Microbial Communities after Irradiation with Accelerated Electrons under Simulated Martian and Open Space Conditions

“…Moreover, it is shown that econiches with liquid water and positive temperatures can occur on the current Mars [88,[90][91][92][93]. Terrestrial microorganisms can grow under combined low pressure, temperature, and anoxic atmosphere conditions [94], it can withstand the impact of Martian salts and strong oxidizers [95][96][97][98], and can survive in subzero brines [99,100]. If even slow repairing of cells' damages occurs, it can be of great effect during geological time.…”

Beyond Chloride Brines: Variable Metabolomic Responses in the Anaerobic Organism Yersinia intermedia MASE-LG-1 to NaCl and MgSO4 at Identical Water Activity

“…Indeed, we observed a high tolerance to desiccation for Y. intermedia MASE-LG-1. Beblo-Vranesevic et al ( 2017b ) documented a decline of survivability by only four orders of magnitude during a storage time of 85 days.…”

“…Y. intermedia has been found in freshwater and marine environments (Shayegani et al, 1981 ), mammals (Babujee et al, 2013 ) and Mars analog environments (Cockell et al, 2017 ), and although it is not considered a human-pathogen, traces were found in urine, stool and wounds (Butler et al, 1984 ; Farmer et al, 1985 ; Punsalang et al, 1987 ). Survivability tests have shown that it can withstand diverse individual and combined stresses like desiccation, X-rays and osmotic stress (Beblo-Vranesevic et al, 2017b ). Yersinia intermedia MASE-LG-1 must have evolved metabolic adaptations to counteract the experienced stress and to minimize damage caused by different stressors.…”

“…Apart from being a powerful osmoprotectant, it has been shown that sucrose was used as a carbon and energy source (Gouffi et al, 1999 ), which might also be the case for Y. intermedia MASE-LG-1. API tests have shown that Y. intermedia MASE-LG-1 can utilize sucrose (Beblo-Vranesevic et al, 2017b ). The KEGG database also revealed three invertase-like enzymes (EC:3.2.1.26) allowing to break down sucrose into glucose and fructose.…”

“…This strain originates from lake Grænavatn (63 53.07′ N, 22 3.70′ W), a maar type explosion crater, with a pH value of around 2 and a mean temperature of 4°C. Its physiology and resistance to Mars relevant stresses have been previously studied (Beblo-Vranesevic et al, 2017b ). We used metabolomics to investigate the effects at the same water activity of two different salts, NaCl and MgSO 4 .…”