Professor Jayant V. Narlikar

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Subject: search.filters.subject.Astrobiology

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    Studies on bacteria-like particles sampled from the stratosphere
    (Springer, 2004-07-28) Wainwright, M.; Weber, P. K.; Smith, J. B.; et al.
    Bacteria-like particles recovered from the stratosphere and deposited on cellulose acetate membranes have been analysed to confirm their bacterial nature. One particle appeared to be attached to an inorganic 2 particle apparently by mucoid material typically produced by bacteria. A filamentous structure, morphologically similar to a fungal hypha, was also observed. EDS analysis showed that the particles were all non-mineral and therefore could be biological in nature. However, the composition several clumps of nanobacteria-sized particles were found, by SIMS analysis, to be inconsistent with that of bacteria. The results show that it is dangerous to assume that bacteria-like particles seen under scanning electron microscopy are necessarily bacteria.
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    Confirmation of the presence of viable but non-culturable bacteria in the stratosphere
    (Cambridge University Press, 2004-01-05) Wainwright, M.; Wickramasinghe, N. C.; Narlikar, J. V.; et al.
    The presence of viable, but non-cultureable, bacteria on membranes through which stratospheric air samples were passed has been confirmed using viable fluorescent staining.
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    Microorganisms cultured from stratospheric air samples obtained at 41 km
    (Elsevier Science Publishers, 2002-12-03) Wainwright, M.; Wickramasinghe, N. C.; Narlikar, J. V.; et al.
    Samples of air removed from the stratosphere, at an altitude of 41 km, were previously found to contain viable, but non-cultureable bacteria (cocci and rods). Here, we describe experiments aimed at growing these, together with any other organisms, present in these samples. Two bacteria (Bacillus simplex and Staphylococcus pasteuri) and a single fungus, Engyodontium album (Limber) de Hoog were isolated from the samples. Although the possibility of contamination can never be ruled out when space-derived samples are studied on earth, we are confident that the organisms originated from the stratosphere. Possible mechanisms by which these organisms could have attained such a height are discussed