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Overview of Microbial Diversity. Three Kingdoms. EUKARYOTES. Algae Red - Rhodophyta Brown - Phaeophyta Green - Chlorophyta Blue-green algae are BACTERIA Cyanobacteria. Fungi Molds Spores / mycelia / hyphae Yeasts / budding. Protozoa Motile / unicellular Pseudopodia Phagocytosis.
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Overview of Microbial Diversity. Three Kingdoms EUKARYOTES Algae Red - Rhodophyta Brown - Phaeophyta Green - Chlorophyta Blue-green algae are BACTERIA Cyanobacteria Fungi Molds Spores / mycelia / hyphae Yeasts / budding Protozoa Motile / unicellular Pseudopodia Phagocytosis PROKARYOTES BACTERIA - Eubacteria ARCHAEA - Archaebacteria
How diverse are they? OXIDISED ATMOSPHERE Plants & Animals • Diverse range of species • Earliest life on the planet • Anaerobic then aerobic • Three Kingdoms (1977) • 16S rRNA Analysis • Eukaryote Plants & Animals • Bacteria • Archaea • Extreme living microorganisms Eubacteria Archaea 3 – 3.5 billion years REDUCED ATMOSPHERE
Microbial Diversity. The Third Kingdom - Archeae – Summary of Differences EubacteriaArchaebacteria Peptidoglycan wall Cell wall variants Ribosomal RNA Very different RNA polymerase Several enzymes Membrane lipids Ether-linked/branched Protein synthesis Very different No methanogenesis Some are methanogens Antibiotic sensitivity Insensitive to many
Prokaryotic cell Eukaryotic cell 10m REAL SIZE of bacterium General differences between Eukaryotes and Prokaryotes
General differences between Eukaryotes and Prokaryotes cont…………. DIRECTED READING: Prescott. Structure Ch3 . Ch4 Archaea Chapter 23
Rickettsia and the origin of mitochondria NATURE12 November 1998 Complete genome of typhus agentNATURE NEWS SERVICE The publication in this week's Nature of the complete sequence of the genome from Rickettsia prowazekii, is not only of considerable medical importance - Rickettsia causes epidemic typhus - but may also shed further light on the evolution of mitochondria. Mitochondria are the energy-generating organelles of most 'higher' organisms and their origin has been much debated. It is generally thought that they arose from a bacterium living symbiotically within a primitive eukaryote cell. Rickettsia prowazekii appears to be very much like this hypothesised ancestor. Alongside the latest research we here re-present a hypothesis, published earlier this year, which sought to explain what drove a Rickettsia-like bacterium to become the ancestral mitochondria.
Rickettsia, typhus and the mitochondrial connectionMICHAEL W. GRAYThe genome sequence of Rickettsiaprowazekii, the agent that causes typhus, has been determined. What emerges is a snapshot of genome re-tailoring in a parasitic bacterium, and a new look at the evolutionary connection between Rickettsia and mitochondria. The genome sequence of Rickettsia prowazekii and the origin ofmitochondriaSIV G. E. ANDERSSON, ALIREZA ZOMORODIPOUR, JAN O. ANDERSSON, THOMAS SICHERITZ-PONTÉN, U. CECILIA M. ALSMARK, RAF M. PODOWSKI, A. KRISTINA NÄSLUND, ANN-SOFIE ERIKSSON, HERBERT H. WINKLER & CHARLES G. KURLAND
The hydrogen hypothesis for the first eukaryoteWILLIAM MARTIN AND MIKLÓS MÜLLER A paradigm gets shiftyW. FORD DOOLITTLEThe prevailing view of the origin of complex eukaryotic cells presumes a symbiosis, based on respiration, between a bacterium and a primitive eukaryotic 'host'. But could the symbiosis have been based instead on hydrogen metabolism, with the host being an archaean?