Archaebacteria are the oldest living organisms on Earth, classified under the kingdom Archaea and characterized as unicellular prokaryotes lacking a cell nucleus and membrane-bound organelles. They thrive in extreme environments, such as volcanic vents and hot springs, and are divided into three categories: methanogens, halophiles, and thermophiles, each adapted to unique conditions. Their genetic functions resemble those of eukaryotes more closely than those of eubacteria.

1. Kingdom Archaebacteria
DEE M. BARRETO – SST-1

2. Archaebacteria are the oldest organism living
on Earth. They are unicellular prokaryotes -
microbes without cell nucleus and any other
membrane-bound organelles in their cells -
and belong to the kingdom, Archaea. They
were first discovered in 1977 by Carl Woose
and George E. Fox and classified as bacteria.
Most archaebacteria appear like bacteria,
when observed under the microscope.
However, they are quite different from
bacteria and eukaryotes.

3. Archaebacteria are found in very
harsh conditions such as in the
volcanic vents or at the bottom of
the sea. They can easily survive in
such extreme environment as sea
vents releasing sulfide-rich gases,
hot springs, or boiling mud around
volcanoes.

4. The word archae came
from the Greek word
Arkhaion, which means
ancient. Archae is also
the Latin name for
prokaryotic cells.

5. A single individual or species from the
Archaebacteria domain is called
archaeon (sometimes spelled
"archeon".) They have no cell nucleus
and no other membrane bound
organelles within their cells. In the past
these rare forms were known as
Archaebacteria but Archean have an
independent evolutionary history and
have shown many differences in their
biochemistry.

7. The Archaebacteria kingdom is
made up of THREE different kinds
of Archaebacteria. The functions
and structures of their genes are
more similar to EUKARYOTES than
to Eubacteria.

8. METHANOGENS
• This type of Archaebacteria live in
oxygen free environments and they
produce Methane gases.
• Places methanogens can be found are:
marshes, lake sediments, and digestive
tracts of animals.
• Commercial use: used in sewage plant
to help breakdown sewage.

10. HALOPHILES
•Halophiles live in water with a
very high concentration of salt.
•Halophiles can be found: in
Utah's Great Salt Lake and The
Dead Sea in the Middle East.

11. Haloccocus dombrowski

12. Halobacterium salinarum

13. THERMOPHILES
•These types of archaebacteria live in
hot areas.
•The water is a very hot/acidic sulfur
spring.
•It is anaerobic and thrives in the
deep cracks of the ocean floor.
•It is also an Autotrophic producer.

15. Mobility of Archaebacteria: two types
of ways
1. some move by using a cilia
thread like structure helps them move
around.
2. others move by using a flagella
a long whip-like tail at one end of the
bacteria
can have one or two flagella
helps the bacteria get a sense of direction.