Evidence that changes in the growth conditions affect the relative distribution of diether lipids in haloalkaliphilic archaebacteria

Taxonomy of the family Halobacteriaceae: a paradigm for changing concepts in prokaryote systematics

The halophilic Archaea of the family Halobacteriaceae (36 genera with 129 species with standing in nomenclature as of November 2011) provide an excellent example of how changing concepts on prokaryote taxonomy and the development of new methods have influenced the way in which the taxonomy of a single group of prokaryotes is treated. This review gives an overview of the taxonomy of the family Halobacteriaceae, showing the impact that methods of phenotypic characterization, numerical taxonomy, chemotaxonomy and especially polar lipid analysis, 16S rRNA gene sequence comparisons, multilocus type analysis and comparative genomics have had on their classification.

Mycobacterium tuberculosis infections in eight species at the National Zoological Gardens of South Africa, 1991-2001

Between 1991 and 2001 a total of 12 cases of Mycobacterium tuberculosis infection in eight different species were recorded in the National Zoological Gardens of South Africa in Pretoria (Tshwane). The genetic relatedness between seven of the M. tuberculosis isolates was determined by IS6110 restriction fragment length polymorphism analysis. For the majority of isolates that were analyzed, a high degree of polymorphism suggested different sources of infection. Evidence of M. tuberculosis transmission between animals is reported in two chimpanzees (Pan troglodytes) housed together, from which samples were collected for analysis 29 mo apart.

A novel prenyltransferase, farnesylgeranyl diphosphate synthase, from the haloalkaliphilic archaeon, Natronobacterium pharaonis

A novel prenyltransferase, farnesylgeranyl diphosphate (FGPP) synthase (EC 2.5.1.X), which synthesizes C25-prenyl diphosphate, was found in the haloalkaliphilic archaeon Natronobacterium pharaonis. It was separated from geranylgeranyl diphosphate (GGPP) synthase (EC 2.5.1.29), which synthesizes C20-prenyl diphosphate, a major prenyltransferase in this organism. The highest activity of FGPP synthase was observed when GGPP was used as the allylic substrate. FGPP synthase may synthesize a precursor for the C25 moiety of C20, C25 diether lipids using a longer allylic diphosphate, such as GGPP synthesized by GGPP synthase, rather than dimethylallyl diphosphate, which is the product of isopentenyl diphosphate isomerase.