Contrasting hypotheses for the taxonomic distribution of photosynthesis among prokaryotes
Nutritional Diversity: Chemoheterotrophs• Saprobes – Decomposers that absorb nutrients from dead organic matter• Parasites – Absorb nutrients from body fluids of living host
Nutritional Diversity: Nitrogen metabolism• Nitrogen fixation – – Conversion of N2 to ammonium – Many bacteria can do it• Other bacteria can convert – Ammonium to nitrate – Nitrate to N2• Remember the nitrogen cycle?
Nutritional Diversity: Oxygen• Obligate aerobes – cannot grow w/out oxygen• Obligate anaerobes – poisoned by oxygen• Facultative anaerobes – will use oxygen if it is there, but can live w/out it
Archaea: Extremophiles• Methanogens – Produce methane as waste – Obligate anaerobes – Live in swamps and marshes – Used as decomposers in waste water treatment plants – In guts of animals that digest a lot of cellulose
Archaea: Extremophiles• Extreme halophiles – Salt lovers – Some require high salinity – bacteriorhodopsin
Archaea: ExtremophilesExtreme Thermophiles– 60-80 degrees Celsius– Some obtain energy by oxidizing sulfur– Found in hot springs and deep-sea hydrothermal vents
A particular slide catching your eye?
Clipping is a handy way to collect important slides you want to go back to later.