Kingdom ArchaebacteriaBy Alexis Avila & Nilanka Lord

Archaebacteria are not fully understood!

Relatively new discovery so we don’t know too much about them

Classification is very difficult Originally classified under Kingdom

Monera with the rest of the bacteria Studies showed that 50% of their

genes did not resemble those of other bacteria

Characteristics of Archaebacteria

Can only live in areas without oxygen

Extremophillic (thrive under extreme conditions)

Prokaryotic (very similar to bacteria) Single-celled No nucleus No membrane bound organelles Navigate using one or more flagella

Size and Shape of Archaebacteria

Volume is about one-thousandth that of eukaryotes

Can be cocci, bacilli, or spirilla in shape

Parts of Archaebacteria

Cell wall that lacks peptidoglycan Phospholipid bilayer

Composed of glycerol-ether lipids, unlike bacteria

One or more flagella

Reproduction

Reproduce asexually via binary fission (prokaryotic) Binary fission: when a single DNA

molecule replicates and two identical cells are created from original cell

Ecological Significance

World's most prolific methane producers Play a big role in digestion in many

organisms Some are found in the gut of humans and

assist in digestion Forms symbiotic relationships with:

▪ Giant tube worms (Riftia pachyptila)▪ Termites▪ Herbivores (like cows and horses)

Suspected to play a role in periodontal disease, but not proven

Modes of Nutrition

Archaebacteria have 4 ways of getting food: Photoautotrophic- Calvin Cycle (light energy +

CO2) Chemoautotrophic- reverse Krebs cycle

(inorganic chemicals + CO2) Photoheterotrophic- use light + organic

chemicals to make food Chemoheterotrophic- undergo respiration,

either Krebs, TCA, or Citric Acid cycle, and then ETC (organic chemicals + CO2)

Uniqueness

Thermotaxis (movement toward extreme temperatures)

Evolution of thermotaxis due to lack of competition for survival

Groups of Archaebacteria

Methanogens

(Make METHANE)

Thermoacidophiles

(Love HEAT & ACID)Halophiles(Love SALT)

Methanogens

Characteristics of Methanogens

Found in oxygen-free environments Produce methane gas from HO2 & CO2

Can live and produce in conditions other bacteria can’t survive in

Most are coccoid or rod-like in shape (few exhibit a plate-like shape)

Cluster of coccoid methanogenshttp://faculty.college-prep.org/~bernie/sciproject/project/Kingdoms/Bacteria3/methano

gens.htm

Methanobrevibacter ruminantium

Found in the guts of rumen (like cows)

Turn H2 into CH4 (methane)

Cows release this methane into the atmosphere

Scientists looking for a way to limit their production of methane

http://202.114.65.51/fzjx/wsw/newindex/tuku/MYPER/a2/750.htm

Halophiles

Characteristics of Halophiles

Require salt-rich environments to survive (due to high internal salt concentration)

Like plants, they use sunlight as a source of photosynthetic energy

Get their color and chemical energy from bacteriorhodopsin (a light-sensitive pigment)

Most are rod-shaped (bacilli)

Halobacterium halobium

Prevalent bacteria in the Great Salt Lake

Can survive in salt concentrations 10x saltier than that of the oceans

http://domescobar.blogspot.com/2011/11/oito-criaturas-da-terra-que-poderiam.html

Owens Lake Bed (Sierra Nevada, California)

http://school.nettrekker.com/goExternal?np=/external.ftl&pp=/error.ftl&evlCode=255279&productName=school&HOMEPAGE=H

Thermoacidophiles

Characteristics of Thermoacidophiles

Can live and thrive in extremely hot, sulferic, and/or acidic environments

Include:Thermophiles= thrive in extremely high temperatures

Acidophiles= pH tolerant (function at 1-5 pH)

Sulfolobus= thrive in sulfur-rich environments

Desulfonauticus submarinus

Live in giant, deep-sea tube worms called Riftia pachyptila

Share a symbiotic relationship with the tube worms

Make food and energy for the tube worms via chemosynthesis

http://bioweb.uwlax.edu/bio203/s2007/rossing_jaco/images/tubeworms.jpgGOVwww.nsf.gov.jpg

Sulfolobus solfataricus

Found in sulfur-rich, acidic environments

Grows optimally at 80⁰C

Capable of living in extremely acidic circumstances (1-5 pH)

http://www.sulfosys.com/tl_files/sulfosys/sulfolobus/Zelle.jpg

AP QUESTIONS!

1) All of the following are examples of substances found in bacteria or archaea EXCEPT:

a) peptidoglycanb) flagellinc) bacteriorhodopsind) chitine) phycobilins

2) Which of the following contains prokaryote organisms capable of surviving extreme conditions of heat and salt concentration?a) archaeab) virusesc) protistsd) fungie) plants

Sources

Archaebacteria http://ic.galegroup.com/ic/scic/ReferenceDetailsPage/ReferenceDetailsWindow?di

splayGroupName=Reference&disableHighlighting=false&prodId=SCIC&action=e&windowstate=normal&catId=&documentId=GALE%7CCV2644030155&mode=view

http://plantphys.info/organismal/lechtml/archaea.shtml http://www.nature.com/ismej/journal/v1/n1/full/ismej20078a.html http://school.nettrekker.com/goExternal?np=/external.ftl&pp=/error.ftl&evlCode=

240911&productName=school&HOMEPAGE=H

http://www.pnas.org/content/101/16/6176.long Methanogens

http://faculty.college-prep.org/~bernie/sciproject/project/Kingdoms/Bacteria3/methanogens.htm

http://www.angelfire.com/ks3/lditton/archaebacteria.html http://www.enotes.com/science/q-and-a/methanogens-halophiles-thermoacidophi

les-3-groups-156123

http://www.hindawi.com/journals/arch/2010/945785/ Halophiles

http://waynesword.palomar.edu/plsept98.htm http://mmbr.asm.org/content/62/2/504.full

Thermoacidophiles http://go.galegroup.com/ps/retrieve.do?sgHitCountType=None&sort=DA-SORT&in

PS=true&prodId=GPS&userGroupName=lcpsh&tabID=T003&searchId=R1&resultListType=RESULT_LIST&contentSegment=&searchType=BasicSearchForm&currentPosition=2&contentSet=GALE%7CA168664452&&docId=GALE|A168664452&docType=GALE&role=ITOF