Text Chapter 18 has a nice set of tables with

1
Text Chapter 18 has a nice set of tables
with characteristics of the major prokaryotic
groups
2
Title
Tree of Life
Text
3
Microbe(s) of the Day Deep-branching
thermophiles Aquificales and Thermotogales
They are thought to have diverged from other
bacteria early (thus similar to the earliest
bacteria, perhaps). Oxidize (eat) hydrogen,
making water in the process 2H2O2 2H20. Live
at high temperatures (50 to 90oC) in hot springs,
hydrothermal vents, hot muds, etc. Aquifex and
Thermatoga species have acquired MANY of their
genes by horizontal gene transfer from Archea and
other groups of bacteria. Recent work by UConn
microbiologists (Ken Noll, Peter Gorgarten and
their students) suggest that Thermatoga species
may not be belong at the base of the bacterial
tree, but with the Firmicutes instead (Bacillus,
Clostridium)
4
Microbe(s) of the Day Deep-branching
thermophiles Aquificales and Thermotogales
Thermotoga maritima wwwuser.gwdg.de/7Eappmibio/r
esearch_liebl.html
Thermocrinis ruber in a Yellowstone hot spring
5
Title
Tree of Life
Text
6
Microbe(s) of the Day Cyanobacteria
Grow a single cells, clusters, filament or
sheets (see morphology lecture) Photosynthetic
bacteria (once called blue-green algae) that
produce O2 as a product of photosynthesis.
Electrons are needed for photosynthesis and they
are taken from water H2O--gt 4H O2. This is
called oxygenic photosynthesis. And it was the
process that originally produced O2 in Earths
atmosphere, 2.3 billion years ago (more later in
the course). Many can convert (fix) atmospheric
N2 into NH3. This process in inactivated by O2
(think about the point above), and is therefore
done when O2 is lacking, or in specialized cells
called heterocysts where the fixation is
protected from O2. Cyanobacteria often contain
internal compartments (most prokaryotes do
not) -Thylakoid membrane in which the
photosynthetic machinary is embedded -Carboxysome
a compartment in which CO2 is fixed into
carbohydrates -Lipid bodies that are storage
compartments for energy-rich compounds -Gas
bodies that help the bacteria float at the right
depth in water, in order to collect light
7
Microbe(s) of the Day Cyanobacteria
Many Cyanobacteria are symbionts with higher
organsms such as lichens, plants and
sponges Many sponge species have their own
specialized Cyanobacterial symbionts that provide
fixed carbon and nitrogen. Sponges are sources of
many interesting compounds that have
antibacterial and anti-cancer properties. Many of
these are actually made by the sponges
cyanobacterial symbionts.
Lobaria pulminaria (Lung lichen) Cross section
Lobaria pulminaria (Lung lichen)
A. Sponges of the Dysidea group
(www.pbase.com) B. Oscillatoria spongeliae (www.
asturnatuar.com) C. Fish killing
cyanobacterial/sponge metabolites (see
Ridley_ChemBiol_2005) D. Antibacterial
cyanobacterial/sponge metabolites
8
Title
Tree of Life
Text
9
Microbe(s) of the DayFirmicutes-endospore formers
-Gram organisms with low amount of G and C in
their genomes (low GCs) -Best know are Bacillus
and Clostridium species Bacillus can grow
aerobically and anaerobically Clostridium
species are strict anaerobes -Both types form
endospores (resistant spores that form inside the
bacteria) Most famous Bacillus species B.
subtilus model organism for Gram bacteria B.
anthracis the anthrax bacterium. Purified
endospores were used in the 2001 anthrax
mailings B. thuringiensis (B.t) and B.
popilliae forms crystals of a toxin which kills
many insects larvae. You can buy either to
sprinkle on your lawn to take care of grubs.
B. popilliae spores for Japanese beetle control
--gt
10
Microbe(s) of the DayFirmicutes-endospore formers
-Clostridium species are club shaped during spore
growth, and are best know for the diseases they
cause C. tetani causes tetanus by making a
toxin that causes muscles to seize up (read about
it here http//en.wikipedia.org/wiki/Tetanus).
C. tetani will grow in anaerobic wounds (like
punctures). Thats why you get a tetanus booster
shot after such injuries. C. botulinum causes
botulism poisoning (and is the source of BoTox).
Organisms grow in anaerobic, non-acidic
environments. Canned goods that are non-acidic
(beans) and that not heated to temps high enough
to kill the organisms are often the source of
outbreaks. http//en.wikipedia.org/wiki/Botulism
C. difficile causes severe diarrhea, often when
other bacteria in the intestine are killed during
antibiotic treatment.
11
Microbe(s) of the Day Non-spore forming
Firmicutes
12
Microbe(s) of the Day Non-spore forming
Firmicutes
-Lactic acid bacteria Cannot use O2 as an
electron acceptor. They ferment and make a
variety of acids including lactic acid. These
bacteria are often used in making fermented milk
products like yogurt and cheeses.
-Staphylococcus sp. are commonly found on the
skin. These are salt tolerant and many of them
are pathogenic. Some of the most serious
infections are caused by Staphylococcus sp. that
are resistant to almost all antibiotics used to
treat them. These are a serious public health
threat. -Streptococcus sp. are often found in
the oral cavity and can also cause serious
disease including strep throat (not too serious),
pneumonia, scarlet fever and sometimes severe,
quickly moving, tissue damage (necrotizing
fasciitis) .
13
Microbe(s) of the DayNon-spore forming
Firmicutes
-Mollicutes bacteria that lack a cell wall. Best
studied are the Mycoplasmas. These are small,
have some of the smallest genomes known in
free-living organisms (500 genes). They need few
genes because they only live in association with
hosts which provide them with nutrients
Mycoplasma species can cause disease
Mycoplasma pneumoniae walking pneumonia,
meningitis Mycoplasma genetalium discovered
in 1980, causes STDs
14
Microbe(s) of the Day the proteobacteria (?
subgroup)
All proteobacteri are Gram - The ?-prots are a
large, well studied and extremely diverse group.
They include
Photoheterotrophs bacteria that can use light
for energyand organic molecule for carbon. Often
called purple bacteria Pigmented when
photosynthesizing. Usually photosynthesize when
in anaerobic environments Found in water and
soils. Examples Rhodobacter, Rhodopseudomonas
These are growing or were collected where
waters were anaerobic, but still irradiated with
light
15
Microbe(s) of the Day the proteobacteria (?
subgroup)
All proteobacteri are Gram - The ?-prots are a
large, well studied and extremely diverse group.
They include
Methanotrophs bacteria that can oxidize
1-carbon compounds such as methanol or methane.
One widely spread group is the Methylobacterium
genus. These are found in soil, water and are
easily isolated from plant leaves.
16
Microbe(s) of the Day
17
Microbe(s) of the Day
18
Microbe(s) of the Day
19
Microbe(s) of the Day
20
Microbe(s) of the Day
21
Microbe(s) of the Day
22
Microbe(s) of the Day
23
Microbe(s) of the Day
24
Microbe(s) of the Day
25
Microbe(s) of the Day
26
Microbe(s) of the Day
27
Microbe(s) of the Day
28
Microbe(s) of the Day
29
Microbe(s) of the Day
30
Microbe(s) of the Day