BACTERIA

Page 1

2 types of cell wall

Gram negative -Thin layer of peptidoglycan

Gram positive -Thick layer of peptidoglycan

Page 2

Gram negative Bacteria with cell wall

contain most Bacteria

have 2 groups

Nonphototrophic

phototrophic -oxygen and anoxygenic

Page 3

Nonphototrophic

14 subgroup where 6 subgroups are pathogen

Subgroups that are pathogen

Enteric group

facultative anaerobic short rods

example: E.coli caused urinary tract infection and gastrointestinal illness

2. Campylobacter and Helicobacter

Aerobic or microaerophilic

motile

example: Campylobacter jejuni caused diarrhea and Helicobacter pylori caused ulcer

3. Spirochetes

morphology: slender and long with flexible and helical shape

mechanism of motility: corkscrew movement

caused syphilis and lyme disease

4. Chlamydias

obligate intracellular parasite

resemble virus: intracellular parasites and small size

differ from virus: have both DNA nand RNA, plasma membrane, functioning ribosomes, metabolic pathway and reproduce by binary fission

caused eye/genitourinary tract infection

Page 4

Subgroup that are non pathogenic

1. Pseudomonas, Azobacter, Rhizhobium

Pseudomonas sp used to degrade complex organic molecules in soil

Azobacter and Rhizobium used for Nitrogen fixation in soil.

Page 5

Phototrophic

Anoxygenic

Photosynthesis under anaerobic condition

H2S, Sulfur, H2 and organic matter as electron donor

no chlorophyll but with bacteriochlorophyll

do not release oxygen during photosynthesis

habitat: deep inside ponds and lakes

non pathogenic

examples: Chromatium, Chlorobium and Rhodospirillium

Chromatium

violet/purple red

internal sulfur granules

purple sulfur bacteria

Chlorobium

green

external sulfur granules

green sulfur bacteria

green sulfur bacteria

Rhodobium

red

do not form sulfur granules

purple non-sulfur bacteria

Page 6

Oxygenic

photosynthesis under aerobic condition

water as electron donor

with chlorophyll

release oxygen during photosynthesis

habitat: surface of ponds and lakes

non pathogenic

example: cyanobacteria (blue-green pigment)

Page 7

Gram positive Bacteria with cell wall

Have 6 groups

1. Gram positive cocci

In pair,chain or cluster

Example: Streptococcus

pneumonia and Staphylococcus

Page 8

2. Endospore forming gram positive Bacteria

Rod-shaped

Habitat: in soil

Genus: Bacillus and Clostridium

Bacillus

Aerobes and facultative anaerobes

Application: biological insecticides

Examples: Bacillus

sphaericus and Bacillus

thuringiiensis

Clostridium

Obligate anaerobes

Clostridium botulinum caused

botulism

food borne pathogen

exotoxin produced –neurotoxin

flaccid paralysis –inhibition nerve excitation

plastic surgery

Clostridium tetani caused paralysis

infect deep wounds

potent neurotoxin

spastic paralysis –inhibition nerve relaxation

Clostridium perfringens

gas gangrene, gas that clogs blood vessels

Page 9

3. Regular nonspore forming gram positive Bacteria

Rod-shaped

Example: Lactobacillus

Homofermentative: produce lactic acid through

Embden-pathway

Heterofermentative: produce lactic acid, ethanol

and carbon dioxide through pentose phosphate pathway

Page 10

4. Irregular nonspore forming gram positive

Bacteria

Club-shaped

Napping binary fission

Example: Corynobacteriunm

diphtherine

Page 11

5. Mycobacteria

Slightly curved to straight rods

Acid-fast stain

Slow grower

Cell wall containing mycolic acid

Growth stimulated by lipid and fatty acids

Example: Mycobacteria

tuberculosis

Page 12

6. Actinomycetes

Branching bacteria

Soil inhabitant

Antibiotic producer –Chloromphenical,

Erythromycin and Tetracycline

Example: Streptomyces

Page 13

Bacteria lacking cell

wall

Mycoplasma

No peptidoglycan and stained pink with Gram

staining

DNA sequences similar to gram positive bacteria

Irregular shape

Protoplast but resistant to osmotic lysis

Strong plasma membrane –have sterol or

lipoglycan

Require organic growth factors such as

cholesterol, fatty acids, vitamin, amino acids and nucleotides/growth