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Title: Studies in relation to the possible extraterrestrial origin of bacteria
Author: Laswd, Amar Abdusalam
ISNI:       0000 0001 3605 3620
Awarding Body: University of Sheffield
Current Institution: University of Sheffield
Date of Award: 2008
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Studies were made in relation to the theory of panspermia, in particular, the version known as cometary panspermia, which suggests that life on Earth a) originated from space (from comets) and b)continues to arrive from this source (Le. neopanspermia). The following conclusions were arrived at; I) Evidence is provided to support/recent findings showing that viable bacteria are present ill the stratosphere at a height of 41 km (circa 25 miles). These bacteria appear in clumps of a size in excess of 10-20 microns. It is argued that it is unlikely that bacterial clumps of this size could be elevated from Earth to 41 km and that as result these clumps must be incoming from space. It is suggested that these may be unculturable and may make up the majority of unculturable bacteria that are found in the environments of Earth (this suggestion is however, remains conjectural). 2) Studies were made on the Red Rain that recently fell on Kerala in India. It was confirmed that Red Rain is made up of microbial cells of morphology similar to that of algae and fungal spores. Another type of Red Rain, sampled in England, is algal in appearance, although morphologically it is completely different from the Red Rain of Kerala. 3) The chemical composition of a comet was simulated. The simulated comct was shown to be capa~le of supporting the growth or bacteria directly sampled from the atmosphere on Earth. Bacteria grew in the presence and absence of the PAH, naphthalene. Thc results suggest that Earth bacteria could grow in the nutrient conditions provided by a comet. 4) Sulphuric acid at a concentration in excess of those likely to be found in the stratosphere did not completely sterilise a culture of Bacillus subtilis, showing that this acid, although present ill the stratosphere, is unlikely to completely inhibit bacterial survival in this environment. 5) A study was made of the microbiology of rocks (i.e. amber, coals, limestone and clay). A large numbcr of bacteria were isolated from clay (mainly species of Bacillus) While two bacteria were isolated from amber and one from a coal sample, no organisms were isolated from limestonc. Obviously, the theory of geopanspermia, the view that bacteria arc transmitted through space in rocks, requires such a demonstration that rocks on Earth do in fc1ct harbour bacteria.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available