Kingdom Archaebacteria

By Alexis Avila & Nilanka Lord Kingdom Archaebacteria

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 lackspeptidoglycan • Phospholipidbilayer • 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 (Riftiapachyptila) • 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 Thermoacidophiles (Love HEAT & ACID) Methanogens (Make METHANE) 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 coccoidmethanogens http://faculty.college-prep.org/~bernie/sciproject/project/Kingdoms/Bacteria3/methanogens.htm

Methanobrevibacterruminantium • Found in the guts of rumen (like cows) • Turn H2into 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)

Halobacteriumhalobium • 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

Desulfonauticussubmarinus • Live in giant, deep-sea tube worms called Riftiapachyptila • 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

Sulfolobussolfataricus • 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: • peptidoglycan • flagellin • bacteriorhodopsin • chitin • phycobilins

2) Which of the following contains prokaryote organisms capable of surviving extreme conditions of heat and salt concentration? • archaea • viruses • protists • fungi • plants

Sources • Archaebacteria • http://ic.galegroup.com/ic/scic/ReferenceDetailsPage/ReferenceDetailsWindow?displayGroupName=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-thermoacidophiles-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&inPS=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

Kingdom Archaebacteria