Studies on the extremely halophilic archaebacteria.

A variety of techniques have been employed to study the taxonomic relationships within a large number of extremely halophilic archaebacteria, including both alkaliphilic and neutrophilic isolates. These techniques include a computer-assisted analysis of whole cell and ribosomal protein patterns, after separation by one-dimensional SDS- polyacrylamide gel electrophoresis. The API-ZYM system has been applied to the extreme halophiles to produce, and then compare, the partial enzyme profiles of a large number of strains. The serotaxonomy of the major cell envelope component of the archaebacterial halophiles (a 200 KD glycoprotein) has been investigated. The cell envelope structure was further investigated by the use of scanning and transmission electron microscopes to study the cell surface topography and composition of a number of extreme halophiles, both rodshaped and coccoid is elites. A brief investigation of the plasmid DNA present in many of the isolates was carried out by preforming hybridization experiments between plasmids from different strains. Ross and Grant (1985) have suggested that the taxonomy of the extremely halophilic archaebacteria should be revised and that these organisms should be divided into two families, comprising a total of nine genera. The work reported in this thesis provides further evidence that, in general, these suggestions are valid.