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Archaebacteria and Eubacteria. Bacteria - small one celled organisms (Prokaryotic) Bacteria like a warm, dark, and moist environment They are found almost everywhere: -water -air -soil -food -skin -inside the body -on most objects. Kingdom Archaebacteria.
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Bacteria -small one celled organisms (Prokaryotic) • Bacteria like a warm, dark, and moist environment They are found almost everywhere: • -water -air • -soil -food • -skin -inside the body • -on most objects
Kingdom Archaebacteria • Prokaryotic • Cell wall without peptidoglycan • Heterotrophs • Saprophytic or parasitic • Asexual (binary fission) • Live in extreme conditions Eg. methanogens (animal gut), extreme thermophiles (Heat), extreme halophiles (Salty)
Kingdom Eubacteria 2 sub groups: Bacteria or Cyanobacteria (photosynthetic with chlorophyll in cytoplasm) • Prokaryotic • Cell wall contains peptidoglycan • Heterotrophs or autotrophs • Asexual (binary fission) • Saprophytic or parasitic • Lives anywhere
Shapes of Bacteria Circular: Coccus Cylindrical: Bacillus Spiral: Spirilla Single (1): Mono Dual (2): diplo Chain: Strepto Clump: Staphylo
Bacteria can be categorized by their Cell wall structure: • Archaebacteria have NO peptidoglycan in their cell wall structure • Eubacteria have peptidoglycan in their cell wall structure and there are 2 types: Gram + and Gram -
GRAM NEGATIVE BACTERIA (eg. E. coli, Salmonella) This diagram shows a Gram - bacteria containing a thin layer of Peptidoglycan and no teichoic acid but have a LPS in the outer membrane
GRAM POSITIVE BACTERIA (eg. many Bacilli) Gram + bacteria have a thicker peptidoglycan layer to protect the cell membrane and 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.
Is this gram stain positive or negative? Identify the bacteria.
Penicillin, an antibiotic, comes from molds of the genus Penicillium Notice the area of inhibition around the Penicillium. Penicillin kills bacteria by making holes in their cell wall – attacks peptidoglycan Unfortunately, many bacteria have developed resistance to this antibiotic. Some bacteria like Actinomycetes produce antibiotics such as streptomycin and nocardicin.
Depending on the species, bacteria can be Aerobic which means they require oxygen to live (obligate aerobes) or • Anaerobic which means oxygen is deadly to them (obligate anaerobes) (eg. Clostridium) • Bacteria that can live with or without oxygen are called Facultative anaerobes (eg. E.coli, Staphylococcus)
HOW BACTERIA GET THEIR FOOD: • AUTOTROPHS: • Photosynthesis (converting light into glucose) • 2. Chemosynthesis • (converting chemicals • into energy) • Eg. nitrifying bacteria Eg. cyanobacteria
HOW BACTERIA GET THEIR FOOD: HETEROTROPHS: 3. Feeding off other organisms to get nutrients eg. Saprophytic bacteria or Decomposers Symbiotic bacteria (Nitrogen fixing Bacteria found in leguminous plants) Pathogenic bacteria
Other Bacteria live symbiotically in the guts of animals or elsewhere in their bodies (in balanced numbers) • For example, bacteria (E.Coli ) in your gut produce vitamin K which is essential to blood clot formation.
Bacteria put the tang in yogurt and the sour in sourdough bread. Streptococcus thermophilus in yogurt
Endospore • Highly resistant structure • Bacteria can survive unfavorable (radiation, UV light, boiling at 120o C) conditions by producing an endospore. • Major cause of food poisoning because can survive boiling & freezing
BINARY FISSION CONJUGATION Bacteria can reproduce by conjugation (it is not sexual reproduction) or asexually by binary fission.
Some can reproduce every 20 minutes (one bacteria could be an ancestor to one million bacteria in six hours) BINARY FISSION DIVISION COMPLETE