Prokaryotic Microbes Supplemental instruction Designed by Pyeongsug Kim ©2010 Fall 2010 For Dr. Wright’s Bio 7/27 Class Updated: Monday, July 12, 2010 Picture from

Prokaryotes -Domain _________ and _________. -classified based on _______ source and _______ source. carbon(C)energy 01-HeatLovingProkaryotes.jpg 38ed4fbd1d20.jpg BacteriaArchaea Designed by Pyeongsug Kim, ©2010

Cells need energy (ATP) -ATP  -Electrons used for ATP synthesis transferred to the molecule(=_______________________) -Terminal electron acceptors(TEA) eg. O 2 for aerobes We, humans are aerobic organisms. Universal energy carrier terminal electron acceptors Designed by Pyeongsug Kim, © Many pathogens are aerobic chemooganotrophs. We are aerobic chemoorganotrophs!

Early earth -Anoxic (anaerobic environment) -Few organic material (few living organisms) -Anaerobes, chemotrophs TEA: S, CO 2 Fermenters ~ TEA as organic(Pyruvates) Create aerobic environment *Earliest earth __________________ Later earth - Aoxic - Aerobes TEA: O 2 Create aerobic environment  Anaerobes can live mouth due to aerobes consume O 2. Anaerobic chemolithotrophs Designed by Pyeongsug Kim, ©2010

Aerobes - terminal electron acceptor is ______. ( most / least) efficient at generating ATP -Obligate aerobes, Facultative anerobes (if O2 presence) Anaerobes - terminal electron acceptor is ____________ - Do not use Krebs cycle (e.g., CO 2, S, SO 4-, NO 3- or NO 2- ) ( less / most ) efficient than aerobic respiration -Methanogens, sulfur bacteria, … Fermenters - terminal electron acceptor _____________. (e.g. pyruvate) (most / least) efficient at generating ATP -Facultative anerobes (if O2 absent) E.Coli Terminal electron acceptor oxygen inorganic molecule organic molecule Designed by Pyeongsug Kim, ©2010

Classified by energy (ATP) source PhototrophsPhototrophs -ATP from ________ -serve as food sources for other organisms. -Aquatic, lakes, bogs, upper layer of muds -Photosynthetic organisms Anoxygenic don’t generate O 2 e.g. purple bacteria, green bacteria Oxygenic generate O 2 e.g. plants, algae, cyanobacteria, sunlight mI/AAAAAAAAA_o/- S2QQsiHZDM/s320/Spirogyra_conjugation.jpg t%20Flats/Salt%20Flats.html Designed by Pyeongsug Kim, ©2010

OrganotrophsOrganotrophs = Chemorganotrophs -Organisms use organic sources (like glucose or sugar) - Aerobes O2 as TEA  most efficient at generating ATP - Anerobes inorganic molecules(e.g., S, SO4-, NO3- or NO2-) as TEA Sulfur bacteria, fermenters, Archea Designed by Pyeongsug Kim, © LithotrophsLithotrophs = Chemolithotrophs - Some use inorganic molecules (lithotrophs) eg. H 2 - Anaerobic environments eg. GI tract in human -TEA: CO 2 or Sulfur(S) - Most Archea living in hydrothermal vent, Aquatic bacteria. -Methanogens (energy from H 2,CO 2 as TEA) Picture from

Cells need Carbon (C) Designed by Pyeongsug Kim, ©2009 AutotrophsAutotrophs - Carbon source from ______. - make sugar (organic compound) Heterotrophs(organotrophs)Heterotrophs(organotrophs) - Carbon source organic molecules(sugar or glucose) from ____________. - produce inorganic molecules e.g. CO 2 CO 2 autotrophs

Methanogens - A group of archaea - Anaerobic chemolithotrophs - ATP from H 2 - TEA: CO 2 - may live a/w fermenters  fermenter produce H 2, CO 2 - produce methane and water - sewage, intestinal tracts, etc. - Hard to culture in the lab. - Future energy source for human. Designed by Pyeongsug Kim, ©2010

organic coumpounds Anaerobic chemoorganotrophsAnaerobic chemoorganotrophs -ATP from __________________ -Sulfur bacteria, fermenters, Archea Sulfur & sulfur-reducing bacteria -Anaerobic respiration -TEA: S, Sulfate(SO 4 2- )  reduce to form H 2 S or HSO 4 −, - Sulfur cycle - Rotten-egg small since H 2 S is generated. - live in anaerobic soils - Produce H 2 S  turn mud and water black. - Most mesophiles or thermophiles Designed by Pyeongsug Kim, © Sulfur reducing Archaea Sulfur reducing Archaea -TEA: S, Sulfate(SO 4 2- ) -Hyperthermophiles ~ live Hydrothermal vents

Anaerobic chemoorganotrophsAnaerobic chemoorganotrophs (Con’td)Fermenters -Clostridium obligate anaerobes endospores (dormant form) vegetative cells live in anaerobic conditons created by aerobes. ferment cellulose, sugar, ethanol foul-smell -Lactic acid bacteria obligate fermenters. *can live in O 2 presence. But not use O 2 produce lactic acid normal flora; live in mouth,throat, vigina, GI tract Milk products: cheese, yogurt Streptococcus, Lactococcus, Enterococcus,… Designed by Pyeongsug Kim, ©2010

-Yeast *but yeast is eukaryotes. bread, beer, wine makes CO 2 -Propionibacterium used in cheese production makes CO 2 Anaerobic chemoorganotrophsAnaerobic chemoorganotrophs (Con’td) Fermenters (Con’td) Designed by Pyeongsug Kim, ©2010

There are three major groups of photosynthetic bacteria. Designed by Pyeongsug Kim, © Purple bacteria ~ anoxygenic ( do not produce O 2 ) cell membrane Photosynthetic system(pigments) in cell membrane. Cyanobacteria ~ oxygenic ( produce O 2 ) use water as an electron donor Photosynthetic system(pigments) in phycobilisomes Green bacteria. ~ anoxygenic ( do not produce O2 ) chlorosomes) Photosynthetic system(pigments) in a vesicles(chlorosomes).

Cyanobacteria xygenic phototrophs Cyanobacteria ~Oxygenic phototrophs -oxygenic phototrophs. *generate O 2 -Primary producers - Contain chlorophyll and psychobiliproteins to harvest energy from light. -Nitrogen fixers metabolize nitrogen. -Heterocyst Specialized thick-walled cell Protect enzyme from oxygen. Helps provide nutrients for other organisms Do not generate O 2 -”Blooms” Excessive growth of cyanobacteria Designed by Pyeongsug Kim, ©2010

Designed by Pyeongsug Kim, © Purple bacteria~Anoxygenic phototrophs cell membrane - Photosynthetic pigments within cell membrane -Gram negative -Most aquatic habitats -Electron source from H 2 S or organic compounds. - do not use electron source from water  do not produce oxygen -Purple sulfur bacteria live in sulfur spring Energy from H2S, H2, organic(pyruvate) gas vesicles(sulfur granules)  sulfur oxidizer! -Purple non-sulfur bacteria live a variety of aquatic habitats, moist soils, paddy fields… lack gas vesicles organic molecules as source of electrons or other diverse metabolism Picture from modern_farmers/ modern_farmers/

Designed by Pyeongsug Kim, © Green bacteria~Anoxygenic phototrophs -Photosynthetic pigments within chlorosomes -Gram negative -harder to observe -Green sulfur bacteria Electron source from H 2 S,( H 2 S  S ) All strict anaerobes gas vesicels(sulfur granules)  sulfur oxidizer! None is chemotrophs Green non-sulfur bacteriaGreen non-sulfur bacteria diverse metabolism; alternative use H 2 or H 2 S All strict anaerobes gas vesicels None is chemotrophs; organic molecules as source of electrons. Grow in the dark aerobically using chemotrophic metabolism. Only Chloroflexus can be grown in pure culture. Picture from