Biology - ARCHAEBACTERIA & EUBACTERIA

Archaebacteria

Methanogens These Archebacteria are anaerobes. They make methane (natural gas) as a waste product. They are found in swamp sediments, sewage, and in buried landfills. In the future, they could be used to produce methane as a byproduct of sewage treatment or landfill operation.

HalophilesThese are salt-loving Archaebacteria that grow in places like the Great Salt Lake of Utah or salt ponds on the edge of San Francisco Bay. Large numbers of certain halophiles can turn these waters a dark pink. Pink halophiles contain a pigment very similar to the rhodopsin in the human retina. They use this visual pigment for a type of photosynthesis that does not produce oxygen. Halophiles are aerobes, however, and perform aerobic respiration.

Extreme halophiles can live in extremely salty environments. Most are photosynthetic autotrophs. The photosynthesizers in this category are purple because instead of using chlorophyll to photosynthesize, they use a similar pigment called bacteriorhodopsin that uses all light except for purple light, making the cells appear purple.

ThermophilesThese are Archaebacteria from hot springs and other high temperature environments. Some can grow above the boiling temperature of water. They are anaerobes, performing anaerobic respiration.

Thermophiles are interesting because they contain genes for heat-stable enzymes that may be of great value in industry and medicine. An example is taq polymerase, the gene for which was isolated from a collection of Thermus aquaticus in a Yellowstone Park hot spring. Taq polymerase is used to make large numbers of copies of DNA sequences in a DNA sample. It is invaluable to medicine, biotechnology, and biological research. Annual sales of taq polymerase are roughly half a billion dollars.

Eubacteria

• Bacteria are prokaryotic and unicellular.

• Bacteria have cell walls, contain peptidoglycan, not cellulose

• Bacteria have circular DNA called plasmids

• Bacteria can be anaerobes or aerobes.

• Bacteria are heterotrophs or autotrophs.

Struktur dasar sel bakteri

Sitoplasma

Ribosom

Nukleoid (DNA)

Membran plasma

Dinding selPeptidoglikan

Membran luar

Kapsul

Bacterial Structures

Characteristics used for Classification:

• RNA sequences and structure• type of nutrition• ability to produce endospores- resistant structures

with cytoplasm and DNA• method of movement• shape, and the way the cells are grouped• composition of cell wall and it’s ability to absorb stain

General Characteristics• are found almost everywhere• are often pathogenic (they make us sick!)• are divided into groups according to:

–their shape–grouping–cell wall–ability to absorb stains

• Bacteria can be autotrophs or hetertrophs.

• Those that are classified as autotrophs are either photosynthetic, obtaining energy from sunlight or chemosynthetic, breaking down inorganic substances for energy .

• Bacteria classified as heterotrophs derive energy from breaking down complex organic compounds in the environment. This includes saprobes, bacteria that feed on decaying material and organic wastes, as well as those that live as parasites, absorbing nutrients from living organisms.

Oxygen Preferences

• obligate aerobes must have oxygen• obligate anaerobes cannot live in

oxygen• facultative anaerobes can grow with

or without oxygen

• Depending on the species, bacteria can be aerobic which means they require oxygen to live

or

• anaerobic which means oxygen is deadly to them.

Green patches are green sulfur bacteria.  The rust patches are colonies of purple non sulfur bacteria.  The red patches are purple sulfur bacteria.

Shapes of Bacteria

What a slide of Typical coccus looks like in a microscope.

Coccus

http://www.uleth.ca/bio/bio1010/Coccus1.jpg

Diplococcus

Streptococcus aurelius

Staphylococcus

Typical Bacillus

Bacillus

http://er1.org/docs/photos/Anthrax/bacillus%20anthracis%20-03.jpg

Typical Bacillus in a Microscope

Spirochetes

Gram Stain• A staining method to differentiate

bacteria

• Gram-negative refers to the inability to retain the deep violet dye

• Gram-positive refers to the ability to retain the deep violet dye

• The Gram stain, which divides most clinically significant bacteria into two main groups, is the first step in bacterial identification.

• Bacteria stained purple are Gram + - their cell walls have thick petidoglycan and teichoic acid.

• Bacteria stained pink are Gram – their cell walls have have thin peptidoglycan and lipopolysaccharides with no teichoic acid.

In Gram-positive bacteria, the purple crystal violet stain is trapped by the layer of peptidoglycan which forms the outer layer of the cell. In Gram-negative bacteria, the outer membrane of lipopolysaccharides prevents the stain from reaching the peptidoglycan layer. The outer membrane is then permeabilized by acetone treatment, and the pink safranin counterstain is trapped by the peptidoglycan layer.

Gram Staining

Gram Negative cells Gram Positive Cells

Is this gram stain positive or negative? Identify the bacteria.

Is this gram stain positive or negative? Is this gram stain positive or negative? Identify the bacteria.Identify the bacteria.

Bacteria Photos

Anthrax

Clostridium perfringes

Bacteria Photos

E. coliClostridium tetani

Bacteria Photos

Staphylococcus aureus

Neisseria gonorrhoeae

Bacteria Photos

Strep

• Bacteria can reproduce sexually by conjugation or asexually by binary fission.

Asexual Reproduction

• Binary Fission – cells grow in size the split in two…. Genetically identical

Sexual Reproduction (exchanging DNA) Conjugation

• two bacteria join together and exchange portions of DNA

F-Pilus for Conjugation

Transformation

DNA is taken in by a bacterium, and then used.

Transduction

DNA is transferred to a bacterium by a virus.

Endospore

• Bacteria can survive unfavorable conditions by producing an endospore.

Endospores• When

environmental factors become harsh bacteria will either die or form endospores.

• If bacteria have time, if the environmental changes are slow enough, they usually form endospores.

Examples of Symbiotic Relationships

• Mutualism – E. coli in the intestines of mammals aid in digestion.

• Parasitism – some bacteria are parasites. They live in a host and eventually overpopulate. As they do they use the host’s food and water, and eventually they starve the tissues.

Beneficial Uses/Effects

• chemical recyclers (Nitrogen Cycle)• the production of HGH, Insulin, Etc.,

through Genetic Engineering• oil spill cleanup• synthesis of Vitamins in your

intestines

• Bacteria are often maligned as the causes of human and animal disease. However, certain bacteria, the actinomycetes, produce antibiotics such as streptomycin and nocardicin.

Bacterial Diseases

• Anthrax• Botulism• Lyme Disease• Salmonella• Tetanus• Tooth decay• Tuberculosis

Strep Throat

Staph Infection

• Other Bacteria live symbiotically in the guts of animals or elsewhere in their bodies.

• For example, bacteria in your gut produce vitamin K which is essential to blood clot formation.

• Still other Bacteria live on the roots of certain plants, converting nitrogen into a usable form.

• Bacteria put the tang in yogurt and the sour in sourdough bread.

• Saprobes help to break down dead organic matter.

• Bacteria make up the base of the food web in many environments.

Streptococcus thermophilus in yogurt

Cyanobacteria

• are photosynthetic autotrophs that produce carbohydrates and oxygen

• tend to cling together in chains or colonies

• contain enzymes that allow them to “fix” atmospheric nitrogen

CyanobacteriaThis is a group of bacteria that includes some that are single cells and some that are chains of cells. You may have seen them as "green slime" in your aquarium or in a pond.

Cyanobacteria can do "modern photosynthesis", which is the kind that makes oxygen from water. All plants do this kind of photosynthesis and inherited the ability from the cyanobacteria.

Cyanobacteria were the first organisms on Cyanobacteria were the first organisms on Earth to do modern photosynthesis and they Earth to do modern photosynthesis and they made the first oxygen in the Earth's made the first oxygen in the Earth's atmosphereatmosphere..

http://www.mhhe.com/biosci/genbio/maderbiology7/graphics/mader07b/online_vrl/images/0510l.jpg

Filamentous: Chain of cells

http://www.spea.indiana.edu/joneswi/e455/Anabaena.jpg

Oscillatoria

http://botit.botany.wisc.edu:16080/images/130/Bacteria/Cyanobacteria/Oscillatoria/Oscillatoria_MC.jpg

Anabaena

_ http://www.bio.mtu.edu/~jkoyadom/algae_webpage/ALGAL_IMAGES/cyanobacteria/Anabaena_jason_dbtow17 2016.jpg

Some filamentous cyanobacteria have Heterocysts, which are Nitrogen-fixing structures

http://www.people.vcu.edu/~elhaij/IntroBioinf/Scenarios/heterocyst2.JPG

The role of bacteria in the Nitrogen cycle