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Exoplanetary environments to harbour extremophile life as we don´t know it

Exoplanetary environments to harbour extremophile life as we don´t know it. Claudia LAGE lage@biof.ufrj.br Instituto de Biofísica Carlos Chagas Filho Universidade Federal do Rio de Janeiro/Brazil. Outline General surviving strategies to extreme environments found in micro-organisms

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Exoplanetary environments to harbour extremophile life as we don´t know it

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  1. Exoplanetary environments to harbour extremophile life as we don´t know it Claudia LAGE lage@biof.ufrj.br Instituto de Biofísica Carlos ChagasFilho Universidade Federal do Rio de Janeiro/Brazil ASTROBIO 2010 Santiago, Jan 15

  2. ASTROBIO 2010 Santiago, Jan 15 Outline General surviving strategies to extreme environments found in micro-organisms Deinococcus, a radiation survivor Searching for new extremophiles on Earth Concerns on the Panspermia connection with life as we don´t know it

  3. ASTROBIO 2010 Santiago, Jan 15

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  5. The quest for perfect DNA duplication involves a protein complex ASTROBIO 2010 Santiago, Jan 15

  6. Hyperthermophilic organisms mixed functions of an entire protein complex in a single protein DNA primase DNA helicase DNA polymerase Rossi et al., J Bacteriol, 2003 ASTROBIO 2010 Santiago, Jan 15

  7. Stronger surface charges cause hyperthermophilic proteins to stabilise complexes under higher temperatures Archaeal PCNA Yeast PCNA ASTROBIO 2010 Santiago, Jan 15

  8. Low-temperature dependence for cold-loving species growth ASTROBIO 2010 Santiago, Jan 15

  9. Membrane lipid structure in mesophilic organisms Membrane lipid structure in cold-loving micro-organisms Low-temperature adaption of cold-loving species membranes ASTROBIO 2010 Santiago, Jan 15

  10. Solvent (concentration)‏ log Pow Staphylococcus sp. strain ZZ1 B. cereus strain ZZ2 B. cereus strain ZZ3 B. cereus strain ZZ4 Hexane 100 mM [1.3% (v/v)] 3.5 +++ +++ +++ +++ Cyclohexane 100 mM [1% (v/v)] 3.2 +++ +++ +++ +++ p-Xylene 100 mM [1.2% (v/v)] 3.0 +++ - ± - Toluene 50 mM [0.53% (v/v)] 2.5 +++ +++ +++ +++ Toluene 100 mM [1% (v/v)] 2.5 +++ ± +++ +++ 1-Heptanol 100 mM [1.4% (v/v)] 2.4 - - - - Dimethylphthalate 100 mM [2% (v/v)] 2.3 +++ - +++ +++ Fluorobenzene 100 mM [1% (v/v)] 2.2 +++ +++ +++ +++ Benzene 100 mM [1% (v/v)] 2.0 +++ +++ +++ +++ Phenol 20 mM [0.18% (v/v)] 1.5 +++ - +++ +++ +++ growth overnight (16 h); ± minimal growth overnight; - no growth Isolation and characterization of novel organic solvent-tolerant bacteria, Zahir et al. Extremophiles 2005 Oct ASTROBIO 2010 Santiago, Jan 15

  11. Oceans of organic compounds are present in exoplanets and their moons... e.g. Titan ASTROBIO 2010 Santiago, Jan 15

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  14. They have been here since the beginning (chlorophyll-containing fossilisations in ~2,5Gyr Australian estromatolites) ASTROBIO 2010 Santiago, Jan 15

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  16. ORIGINS OF LIFE ON EARTH S

  17. HOW CLOSE ARE WE TO MICRO-ORGANISMS? STRESS RESPONSES ARE ALWAYS UP-TO-DATE! Homo sapiens Silicibacter sp. www.ncbi.nlm.nih.gov/BLAST/ ASTROBIO 2010 Santiago, Jan 15

  18. What´s up there in outer space? No heat No gases No water ASTROBIO 2010 Santiago, Jan 15

  19. Panspermia Transport Density: 1 to 106 molecules.cm-3 Pressure > 10-17 atm Radiation UV: 122.3 J.m-2.s-1 Temperature = 0 to hundreds K Ejection Reentry ASTROBIO 2010 Santiago, Jan 15

  20. Bacterial SPORES were shown to survive a 6-yr exposure to low Earth orbit radiation Horneck et al., Adv Space Res, 1994 ASTROBIO 2010 Santiago, Jan 15

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  22. Observation may be confusing in the search for life… ??? Avenca Mineral deposit on rock ASTROBIO 2010 Santiago, Jan 15

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  24. About Deinococcus... • The radiation constraint… • 4Gy gamma rays to humans =  • 15.000Gy gamma rays to radiodurans •  ASTROBIO 2010 Santiago, Jan 15 Deinococcus radiodurans

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  26. ASTROBIO 2010 Santiago, Jan 15 SIMULATION EXPERIMENT IN THE SINCHROTRON LIGHT NATIONAL LABORATORY, Campinas, Brazil CELL POWDER + HIGH VACUUM + WHITE BEAM VUV SOLAR RADIATION

  27. ASTROBIO 2010 Santiago, Jan 15

  28. http://microbialgenomics.energy.gov/primer/featured_bugs.shtmlhttp://microbialgenomics.energy.gov/primer/featured_bugs.shtml ASTROBIO 2010 Santiago, Jan 15

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  31. Superfície microscópica da fita de carbono ASTROBIO 2010 Santiago, Jan 15 MAUA 17 OUT 2009

  32. ASTROBIO 2010 Santiago, Jan 15 CONCORDIA MICROMETEORITES CARBON TAPE 100µm Morphologic comparison between surfaces of Concordia 2002 micrometeorite (Antartica) and that of the carbon tape on which bacterial powder was layered for irradiation (with permission of M. Maurette)..

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  34. Viability of Deinococcus radiodurans under shielding conditions ASTROBIO 2010 Santiago, Jan 15

  35. Multiple secondary radiation effects enhance energy absorption by a large rock fragment ASTROBIO 2010 Santiago, Jan 15

  36. Micro-sized particles have lower probability to interact with radiation ASTROBIO 2010 Santiago, Jan 15

  37. ATACAMA has life and youdon´tseeit ASTROBIO 2010 Santiago, Jan 15

  38. Sítio Maria Elena – Atacama - Chile Marte ASTROBIO 2010 Santiago, Jan 15

  39. WATER ICE UPON MARS LANDING OF PHOENIX!!! ASTROBIO 2010 Santiago, Jan 15

  40. Searching for novel radiation resistant micro-organisms !!! ASTROBIO 2010 Santiago, Jan 15

  41. UV (254nm) survival of bacterial isolates from Antarctic samples ASTROBIO 2010 Santiago, Jan 15

  42. KOISTRA et al., 1958: The behaviour of microorganisms under simulated Martian environmental conditions. - low pressure chamber (0.06 mbar); - soil samples from distinct geographic regions (in natura specific microflora); - initial counts of colonies and after 1, 2 and 3 months under martian conditions; - environmental “simulation” = cycles of 9h at 25oC, then 15h at -22oC. Results: ASTROBIO 2010 Santiago, Jan 15

  43. Surface temperature estimates for some known exoplanets • The surface temperature estimation depends not only on the stellar temperature but also e.g. on the planet's albedo and atmospheric chemical composition which will define the extent of the greenhouse effect and on how the heat is distributed around the planet • The present sample of known exoplanets is strongly biased: e.g., long period planets are much more difficult to detect. • Surface temperatures of the known exoplanets are on the average higher than for planets in the Habitable Zone (HZ) ASTROBIO 2010 Santiago, Jan 15

  44. Surface temperatures of a number of Neptune-like planets have been estimated (e.g., Rivera et al. 2005, Bonfils et al. 2005; Bonfils et al. 2007; Demory et al. 2007)‏ • They are supposedly mainly composed of icy/rocky material, being formed without or having lost the extended gaseous atmosphere • Some of them have orbital periods between 2 and 6 days and surface temperature ranges from 400 to 700 K • Even in these particular cases, extremophiles existing on Earth (hyperthermophiles) could live even in the coldest of them ASTROBIO 2010 Santiago, Jan 15

  45. MOST FAVOURABLE KNOWN CASE: Gliese 581c (Udry et al. 2007) A 5 MEarth planet in the HZ of a MV (red) star For Earth-like or Venus-like albedos, the surface temperature of Gliese 581c is estimated to range between 270 and 313 K, respectively. Many extremophiles could live under these conditions! ASTROBIO 2010 Santiago, Jan 15

  46. INTERESTING POSSIBILITY: moons of planets in the HZ Jupiter-like planets in the HZ: Examples: HD10697 (G5V ; 6.35 MJ, 1072 d orbit) TS 264 K HD37124 (G4V ; 1.04 MJ, 155.7 d orbit) TS 327 K HD134987 (G5V ; 1.58 MJ, 260 d orbit) TS 315 K HD177830 (K2IV ; 1.22 MJ, 392 d orbit) TS 362 K HD222582 (G3V ; ?? MJ, 576 d orbit) TS 234 K Extremophiles could live “confortably” under these temperatures ASTROBIO 2010 Santiago, Jan 15

  47. SUMMARY OF KEY POINTS The flux of solid material (large dust meteoroids) arriving on Earth from nearby stars was estimated in detail by Murray et al. (2004) from radar detections: ~ 10 yr-1·km-2; estimates on the amount of micro-sized material coming to Earth point to 10,000 TONS/YR !!! We are presently located in an inter-arm (relatively low-density) region of the Galaxy. Each ~70 to 140 million years the solar system traverses a spiral arm region of much higher stellar and gas density. At each crossing of the Sun through a spiral arm, the flux of dust and gas of extra-solar origin arriving on top of terrestrial atmosphere will increase by many orders of magnitude. The Panspermiahypothesismight thus be much more efficient. Microbes coming from other places in the CONTAMINATED GALAXY could use dust grains and micrometeorites as natural vehicles and benefit of the shielding effect operated by MICROPARTICULATE material. Living organisms could have more intensively seeded Earth during crossings of the solar system through dense galactic regions because of shorter times required for any organism to reach Earth. ASTROBIO 2010 Santiago, Jan 15

  48. IN CONCLUSION, Micro-organisms could function as “minimal” biological organization spreading life in many planetary systems. Microbial life could give birth to complex life, upon reaching a minimally viable planet/moon. The ability of extremophile organisms to cope with environmental conditions far beyond conceivable limits should broaden the astronomical concept of HABITABLE ZONE to a biological one, the EXTREMOPHILE ZONE (EZ). ASTROBIO 2010 Santiago, Jan 15

  49. B Brazilian team: MSc Ivan PAULINO-LIMA Dr. João Alexandre R. G. BARBOSA1 Dr. Arnaldo Naves de BRITO1 Prof. Dr. Eduardo JANOT-PACHECO3 Dr Douglas GALANTE3 Gabriel DALMASO 1Laboratório Nacional de Luz Síncrotron – MCT/CNPq 2Instituto de Física – IF/UFRJ 3Departamento de Astronomia – IAG/USP International co-operation: Dr. Nigel MASON, Open University, UK Dr. Charles COCKELL, Open University, UK Armando AZUA-BUSTOS, Univ Católica Chile ASTROBIO 2010 Santiago, Jan 15 SAB 03 set 2007

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