Effects of Stratospheric Conditions on the Viability, Metabolism and Proteome of Prokaryotic Cells

Abstract

Abstract:The application of ultraviolet (UV) radiation to inhibit bacterial growth is based on the principle that the exposure of DNA to UV radiation results in the formation of cytotoxic lesions, leading to inactivation of microorganisms. Herein, we present the impacts of UV radiation on bacterial cultures' properties from the biological, biochemical and molecular biological perspective. For experiments, commercial bacterial cultures (Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli and Salmonella typhimurium) and isolates from patients with bacterial infections (Proteus mirabilis and Pseudomonas aeruginosa) were employed. The above-mentioned strains were exposed to UV using a laboratory source and to stratospheric UV using a 3D printed probe carried by a stratospheric balloon. The length of flight was approximately two hours, and the probe was enriched by sensors for the external environment (temperature, pressure and relative humidity). After the landing, bacterial cultures were OPEN ACCESSAtmosphere 2015, 6 1291 cultivated immediately. Experimental results showed a significant effect of UV radiation (both laboratory UV and UV from the stratosphere) on the growth, reproduction, behavior and structure of bacterial cultures. In all parts of the experiment, UV from the stratosphere showed stronger effects when compared to the effects of laboratory UV. The growth of bacteria was inhibited by more than 50% in all cases; moreover, in the case of P. aeruginosa, the growth was even totally inhibited. Due to the effect of UV radiation, an increased susceptibility of bacterial strains to environmental influences was also observed. By using commercial tests for biochemical markers of Gram-positive and Gram-negative strains, significant disparities in exposed and non-exposed strains were found. Protein patterns obtained using MALDI-TOF mass spectrometry revealed that UV exposure is able to affect the proteins' expression, leading to their downregulation, observed as the disappearance of their peaks from the mass spectrum.

Survival of halophilic Archaea in Earth's cold stratosphere

“…Recently, several commercial bacterial cultures ( Staphylococcus aureus , methicillin-resistant Staphylococcus aureus, Escherichia coli and Salmonella typhimurium ) and human-associated bacteria ( Proteus mirabilis and Pseudomonas aeruginosa ) were launched into the stratosphere on helium balloons (Chudobova et al . 2015). The survival of these bacteria was found to be significantly poorer than for the Haloarchaea in our study, especially H. lacusprofundi .…”

Airborne Bacteria in Earth's Lower Stratosphere Resemble Taxa Detected in the Troposphere: Results From a New NASA Aircraft Bioaerosol Collector (ABC)

“…Since all marine and surface environments are impacted by winds, the emanation/deposition of airborne microorganisms (hereafter referred to as bioaerosols) contributes to ecosystem dynamics. For instance, airborne microorganisms surviving harsh conditions while aloft, including strong levels of mutagenic ultraviolet radiation, might be altered at the genomic, transcriptomic, and proteomic level upon germination in a new environment (Smith et al, 2011 ; Chudobova et al, 2015 ; Waters et al, 2015 ; Khodadad et al, 2017 ). With hundreds of teragrams of microbe-laden dusts from deserts and agricultural soils moving through Earth's atmosphere each year (Acosta-Martinez et al, 2015 ), additional surveys are needed to better understand the ecological consequences of airborne biomass exchange, including disease dispersal (Brown and Hovmoller, 2002 ; Fröhlich-Nowoisky et al, 2016 ; Mahaffee and Stoll, 2016 ; Van Leuken et al, 2016 ).…”

UV-B Radiation Stress Causes Alterations in Whole Cell Protein Profile and Expression of Certain Genes in the Rice Phyllospheric Bacterium Enterobacter cloacae

“…Damaging effects of UV-B radiation on various metabolic processes of different organisms including bacteria and cyanobacteria are well documented ( Häder et al, 2007 ; Rastogi et al, 2011 ; Santos et al, 2012 ; Singh et al, 2013 ; Chudobova et al, 2015 ; Oliveira et al, 2016 ). In the present study, it was noted that UV-B radiation exposure to five strains of phyllospheric bacteria resulted in the loss of survival and complete killing occurred after prolonged exposure.…”

“…UV-B radiation is a cytotoxic wavelength range of solar radiation that exerts several structural and physiological effects on living organisms ( Bancroft et al, 2007 ; Singh et al, 2013 ). Several biological effects of UV-B radiation include alteration in the structure of DNA, proteins, lipids, and other biologically important molecules, enhanced reactive oxygen species (ROS) generation, inhibition of such physiological processes as N 2 fixation, photosynthesis and energy production in several organisms ( Häder et al, 2007 ; Santos et al, 2012 ; Singh et al, 2013 ; Babele et al, 2015 ; Chudobova et al, 2015 ; Kurth et al, 2015 ). In particular, UV-B radiation present in the solar radiation directly damages DNA by inciting the formation of dimers in cellular DNA, including cyclobutane pyrimidine dimers and pyrimidine (6-4) pyrimidinone photoproducts ( Rastogi et al, 2010a ; Santos et al, 2012 ).…”

“…In particular, UV-B radiation present in the solar radiation directly damages DNA by inciting the formation of dimers in cellular DNA, including cyclobutane pyrimidine dimers and pyrimidine (6-4) pyrimidinone photoproducts ( Rastogi et al, 2010a ; Santos et al, 2012 ). Lesions formed in the DNA result in the blockage of DNA replication and RNA transcription leading to cell death ( Santos et al, 2012 ; Chudobova et al, 2015 ).…”