Archaebacteria Archaebacteria and and

EubacteriaEubacteria

What are bacteria?What are bacteria?

►Bacteria are Bacteria are prokaryotes (no prokaryotes (no membrane bound membrane bound nucleus)nucleus)

►Smallest living Smallest living known cellsknown cells

►Found EverywhereFound Everywhere

Bacteria in dental plaque microbeworld.org

►Did you know… Did you know… there are over 80 there are over 80 species of species of bacteria in our bacteria in our mouth!mouth!

Characteristics of BacteriaCharacteristics of Bacteria

►Cell WallCell Wall►Cell (plasma) Cell (plasma)

MembraneMembrane►PiliPili►FlagellaFlagella►CytoplasmCytoplasm►RibosomesRibosomes►DNADNARefer to colored Refer to colored picture in NB for picture in NB for functionsfunctions

ArchaebacteriaArchaebacteria

► Emerged at least 3.5 billion years agoEmerged at least 3.5 billion years ago► Live in environments that resemble conditions Live in environments that resemble conditions

existing when the earth was young existing when the earth was young ►Don’t like oxygen, love acid and heatDon’t like oxygen, love acid and heat►Differ from EubacteriaDiffer from Eubacteria

bases in ribosomal RNA differentbases in ribosomal RNA different composition of plasma membranes and cell walls composition of plasma membranes and cell walls

are differentare different► Three major known phyla (groups)Three major known phyla (groups)

MethanogensMethanogens HalophilesHalophiles ThermophilesThermophiles

MethanogensMethanogens

►Anaerobic (do not Anaerobic (do not need oxygen to need oxygen to survive) survive)

►Produce methaneProduce methane gasgas

►Marshes, sewage Marshes, sewage treatment plants, treatment plants, intestinal tracts of intestinal tracts of humans and humans and some animals some animals (cows).(cows).

HalophilesHalophiles

►AerobicAerobic►High saline/salty High saline/salty

environments environments usually 10 times the usually 10 times the

saline/salt content of saline/salt content of normal oceannormal ocean

Salt lakes (Great Salt lakes (Great Salt Lake, Dead Salt Lake, Dead Sea), pools, sea Sea), pools, sea waterwater

ThermophilesThermophiles►Love heatLove heat

(can survive 230 (can survive 230 degrees Fahrenheit)degrees Fahrenheit)

►Use sulfur and iron Use sulfur and iron for respirationfor respiration

►Extremely acidic Extremely acidic conditions pHconditions pHbelow 2below 2

►Hot Springs and Hot Springs and Thermal VentsThermal Vents

Acid-Sulfur Spring

Yellow Stone National park

EubacteriaEubacteria

►““true bacteria” true bacteria” ►Usually what we refer to as “bacteria”Usually what we refer to as “bacteria”►Usually Usually Neutral conditionsNeutral conditions

Ex: body, food, moist placesEx: body, food, moist places

Eubacteria- The Bad?Eubacteria- The Bad?

►Can cause problems for human healthCan cause problems for human health Streptococci bacteriaStreptococci bacteria cause strep throat cause strep throat E.coliE.coli and Salmonella are sometimes and Salmonella are sometimes

found in undercooked meat and eggs and found in undercooked meat and eggs and can make people sickcan make people sick

Anthrax

Bacillus anthracis

E. coliSalmonella

Eubacteria- The Good?Eubacteria- The Good?

►Other bacteria are Other bacteria are beneficial to human beneficial to human health:health: Fermentation:Fermentation:

►Yogurt, grapes, milk, Yogurt, grapes, milk, cheesecheese

Breakdown waste Breakdown waste (wastewater treatment (wastewater treatment plants + septic systems) plants + septic systems)

►Lactobacillus acidophilus found to have health benefits. Naturally found in mouth, intestinal track, yogurt. Used in yogurt fermentation