Kingdoms and Domains BacteriaArchaeaEukarya BacteriaArchaeaProtistaPlantaeFungiAnimalia MoneraProtistaPlantaeFungiAnimalia The three-domain system The six-kingdom system The traditional (now outdated) five-kingdom system A.K.A. DOMAIN PROKARYA

One bacterium, two bacteria Bacterial Structure: A Typical Bacterium Plasmids Some bacteria also have a capsule outside the cell wall.

Bacteria  Prokaryotes – unicellular, no membrane-bound nucleus or organelles  Most heterotrophic, some autotrophic  Most NOT pathogenic, many useful to us  Mostly microscopic, but not all!  Species are further classified into strains

Bacteria – Two Kingdoms  Archaebacteria – most ancient, found in harsh environments  Methanogens – anaerobic, make methane: digestive tract of animals  Thermophiles – hot water: ocean vents, hot springs  Halophiles – extremely salty water: Great Salt Lake, Dead Sea  Eubacteria – pathogens & all others  Main differences:  Only Eubacteria have peptidoglycan in cell walls  Archaea and Eubacteria have different rRNA / ribosomes

Phylum Methanogens To generate or produce Methane gas Live in swamps and in the intestinal tracts of animals, can cause gas Generates Methane (CH 4 ) gas from CO 2 & H 2 S as waste product

Halophiles Salt Lovers Use salt to produce ATP Salt Lake Dead Sea

Geysers, Hot Pools Phylum Thermoacidophile Heat acid love

(Eu)Bacteria – Benefits to Humans  In the environment:  Cyanobacteria make oxygen  Bacteria in soil fix nitrogen for plants  Bacteria decompose dead matter  Bacteria form symbiotic relationships w/ organisms  Bioremediation – bacteria can be used to clean up pollution Rhizobium in root nodules of legumes

Saprophytic Activity of Bacteria at Sewage Treatment Plants Bioremediation & Decomposition

(Eu)Bacteria – Benefits to Humans  In the environment:  Bioremediation – bacteria can be used to clean up pollution Oil Spill – Bioremediation on Oil

(Eu)Bacteria – Benefits to Humans  In industry:  Bacteria are used in the making of cheese, yogurt, beer, wine, clothes, medicines, etc.;  genetically engineered bacteria can produce proteins/hormones such as insulin

Cosmetic Treatment

(Eu)Bacteria – Benefits to Humans  In our bodies:  The “natural flora” bacteria in our skin and digestive tract (enteric bacteria) keep harmful germs out & help absorb vitamins