Need a little help isolating?
Try this…A split plate selective media
MacConkey – CNA/Blood
MacConkey (pink side)
Should only allow Gto grow
CNA/Blood (red side)
G+ grow better here
WARNING! G- may still show up
Added benefit – IF your
G- organism uses lactose
the colonies will appear pink
on MacConkey
1
These plates can be found in refrigerator on right side of middle shelf
Chapters 10 & 11
Classification of Microorganisms
Archae & Bacteria
2
Whittaker’s Five-Kingdom System:
Procaryotae (Monera) - prokaryotes, unicellular
Protista - eukaryotic, generally unicellular (algae, protozoa)
Fungi - eukaryotic, generally multicellular, saprophytic, chitin
Plantae - eukaryotic, multicellular, photosynthetic
Animalia - eukaryotic, multicellular, ingest food
3
Three Domains (Woese,1978)
Based on comparison of sequences of ribosomal RNA (rRNA)
also differ in:
 lipid membrane structure
 tRNA structure
 response to antibiotics
(see table 10.1 for details)
Domains are a higher level of organization than Kingdoms
4
DOMAINS
Eubacteria - contains the bacteria (prokaryotic)
Archaea - contains the archeabacteria (prokaryotic)
Eucarya - contains all the eukaryotic kingdoms
5
THREE DOMAINS
6
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..
…
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...…
End Chapter 10
7
Bacteria
Bacteria are classified using Bergey’s Manual of Systematic
Bacteriology
Bergey’s Manual is divided into four volumes:
Division within Bergey’s Manual are based on characteristics
such as: Gram reaction, cell shape, cell arrangement, oxygen
requirements, motility, metabolic properties
8
Bergey’s Manual Volumes I - IV
I. Gram-negative bacteria of medical and industrial importance
II. Gram-positive bacteria of medical and industrial importance
III. Other Gram-negative bacteria
IV. Actinomycetes and other Gram-positive bacteria
review table 11.1 pages 305-306
9
Bacterial Groups
Be familiar with major groups in Table 11.1
Know major characteristics which set each group apart from the
others (including habitat and special features)
Be able to identify or place important genera within the
appropriate group
10
Spirochetes
Gram negative cell wall
morphology – helical (corkscrew shaped)
motility by axial filaments (similar to flagella, but located inside
the periplasmic space)
Habitats: aquatic, animal parasites
Important genera: Treponema & Borrelia
T. pallidum = causative agent of syphilis
B. burgdorferi = causative agent of Lyme’s disease
 (transmitted by deer tick)
11
Aerobic, motile, helical/vibrioid bacteria
Gram negative cell wall
morphology either helical or vibrioid (comma shaped)
some fix nitrogen
soil and aquatic habitats, human intestinal tract and oral cavity
Important genera:
Spirillum
Azospirillum – associated with plant roots, nitrogen fixer important to agriculture
Campylobacter - a ‘food poisoning’ bacteria, 1 in 1000 Guillain-Barr Syndrome
Bdellovibrio - predator on bacteria
12
Gram-negative, aerobic
rods and cocci
many industrially, medical, and environmentally important
bacteria.
Habitats include soil, water, animal parasites
13
Important GImportant genera:
Pseudomonas – opportunistic infections in burns
Burkholderia
Legionella – Legionnaire’s Disease
Neisseria - STD
Brucella
Bordetella – whooping & kennel coughs
Francisella
Rhizobium
Agrobacterium
14
Facultatively anaerobic,
Gram-negative rods
many important pathogens
Habitats include soil, plants, animal respiratory and intestinal
tracts
many in this group known also as "enterics" (found in human
intestine)
Important genera:
Escherichia, Salmonella, Shigella, Klebsiella, Yersinia, Vibrio,
Enterobacter, Hemophilus, Gardnerella, Pasteurella
15
Anaerobic, Gram-negative rods
obligate anaerobes (can not live in presence of O2)
Habitats: mostly in intestinal tracts, some in mouth and genital
tract & some of the most common organism in the intestine
Important genera:
Bacteriodes
Fusobacterium
16
Dissimilatory sulfate-reducing or
sulfur reducing bacteria
Gram negative cell wall
found in anaerobic sediments
reduce oxidized forms of sulfur to H2S
dissimilation = nutrients not assimilated but rather excreted
Important genera:
Desulfovibrio
17
Rickettsias & Chlamydias
Gram negative cell wall, obligate intracellular bacteria
many important pathogens, parasites of arthropods and animals
Important genera:
Rickettsia
Coxiella
Ehrlichia - flu-like disease transmitted by ticks
18
Chlamydia – sexually transmitted NGU
(nongonococcal urethritis)
Mycoplasmas
no cell wall (G- reaction), pleomorphic (variable shape)
parasites of animals, plants, insects
some pathogens
Important genera:
Mycoplasma – normal vaginal flora that can opportunistically
cause fallopian tube infection
19
Gram-positive cocci
some important pathogens and industrial organisms
found in soils; skin and mucous membranes of animals
Important genera:
Staphylococcus
Streptococcus
Lactococcus
Enterococcus
20
Endospore-forming rods and cocci
Gram positive cell wall
some important pathogens and industrial organisms
Habitat - found in soils; animal intestinal tract
Important genera:
Bacillus - aerobic or facultative anaerobes
Clostridium anaerobic (C. botulinum - food spoilage)
21
Regular non-spore-forming
Gram-positive rods
some important pathogens and industrial organisms
found in dairy products; genital and oral cavities; animal feces
Important genera:
Lactobacillus - forms lactic acid from carbohydrates
Listeria - animal pathogen
22
Irregular non-spore-forming
Gram-positive rods
pleomorphic
some important pathogens
Habitat: found in soil; human pathogens
\
Important genera:
Gardnerella
Corynebacterium
Propionibacterium
Actinomyces
23
Mycobacteria
Gram positive, some are important pathogens
acid-fast (produce mycolic acids in cell wall)
Habitats: found in soil, plants, animals
Important genus:
Mycobacterium
 leprosy
 tuberculosis
24
Nocardioforms
Gram positive cell wall, some pathogens, some are acid-fast
Habitats: found in soil and animals
form branched filaments, reproduce by fragmentation
Important genus:
Nocardia
 pulmomary infections
 Mycetoma – a destructive infection of hands/feet
25
Budding or appendaged bacteria
Gram negative,
contain prosthecae (protrusions such as stalks or buds)
Habitat: mostly aquatic
Important genera:
Hyphomicrobium
Caulobacter
can grow in low nutrient aquatic environments
sometimes attach to a host and use excretions as nutrients
26
Non-photosynthetic, non-fruiting,
gliding bacteria
Gram negative cell wall
gliding motility
Habitat: aquatic
Important genera:
Cytophaga - degrades cellulose (name means cell eater)
Beggiatoa - oxidizes hydrogen sulfide
27
Gliding, fruiting bacteria
Gram negative cell wall
gliding motility (leaves a slime trail)
cells aggregate to form a fruiting body
Habitats: soil, dung
Important genera:
Myxococcus
When you’re
out of poop,
ya gotta slide!
Under proper conditions (low nutrients) spores germinate to form
new motile, gliding cells which resemble slime molds
28
Aerobic, chemoautotrophic bacteria
Gram negative cell wall
nitrifying and sulfur-oxidizing bacteria
agriculturally and environmentally important
Habitat: soil
Important genera:
Nitrosomonas & Nitrobacter
 reduce nitrogen compounds to nitrates
Thiobacillus
 reduce sulphur compounds to sulfates
29
Archaea
Gram reaction varies
not directly related to bacteria
no peptidoglycan in cell wall
Habitats: found in anaerobic sediments; in extreme environments
Important genera:
Methanobacterium - useful in sewage treatment
Halobacterium (salt loving)
Sulfolobus
30
Anoxygenic, photosynthetic bacteria
Gram negative cell wall
includes green and purple sulfur and non-sulfur bacteria
green and purple sulfur bacteria use H2S as an electron donor and
release sulfur
Habitat: anaerobic sediments
Important genera:
Chromatium
Rhodospirillum
Chlorobium
31
Oxygenic photosynthetic bacteria
(Cyanobacteria)
Gram negative reaction
produce oxygen during photosynthesis
many species fix nitrogen
Habitat: aquatic
Important genera:
Chroococcus
Anabaena – has plant-like photosynthesis
32
Actinomycetes
Gram positive cell wall
branching filaments with reproductive conidiospores (see fig 11.23)
many important industrial organisms
Habitats: soil, some aquatic
Important genera:
Streptomyces - important antibiotic producers, also make a gas
(geosmin) which contributes to the ‘musty’ odor of soil
Frankia - involved in nitrogen fixation with plants
33
Micromonospora – another antibiotic producer
branching filaments with reproductive conidiospores, characteristic of Actinomycetes
34
35