In this slide we explain the reproduction in Bacteria. here we explain the two basic types of reproduction briefly with their types. i,e Sexual Reproduction Asexual reproduction

2. Reproduction in Bacteria
By
MUHAMMAD SAEED SIDDIQUI
BOT-19-27

3. Reproduction in bacteria
Just like any other organism, bacteria also
reproduce to continue their species. Since
they are unicellular and do not have a well-
organised cell, bacteria have been grouped
under prokaryotes. However, they do show
both sexual and asexual means of
reproduction. In this topic, we will have a brief
overview of all types of means of reproduction
in bacteria.

4. Reproduction in bacteria
Bacteria is reproduce in two ways I,e
Asexual reproduction
Sexual reproduction

5. Asexual reproduction
In asexual reproduction in bacteria, 5 methods are observed.
These are:
1. Binary fission
2. Reproduction through conidia
3. Budding
4. Reproduction through cyst formation
5. Reproduction through endospore formation

6. Binary Fission
• In binary fission, a single bacterial cell divides into two
daughter cells.
• At first, the bacterial cell reaches critical mass in its form
and cell components.
• The circular double-stranded DNA of the bacteria
undergoes replication and new complementary strands are
formed.
• These two strands of DNA are then moved to the different
poles of the cell and a transverse septum then takes place
and develops in the middle region of the cell which
separates the two new daughter cells and thus binary
fission I completed.
• It is a rapid process and takes minutes to complete.

8. Conidia Formation
• The formation of conidia takes place in
filamentous bacteria such as Streptomyces
through the formation of a transverse septum at
the apex of the filament.
• The part bearing the conidia is called the
conidiophore and after it is detached from the
mother cell, in a suitable substratum it
germinates giving rise to new mycelium.
• This type of asexual reproduction is also called
fragmentation.

10. Budding
• In this method of reproduction, the bacterial cell
develops a small swelling at one side which
continuously increases in size.
• At the same time, the nucleus also undergoes division
where one part with some cytoplasm enters the
swelling and the other part remains with the mother
cell.
• The outgrowth is called the bud and it eventually gets
separated from the mother cell by a partition wall. This
method of reproduction also comes under vegetative
reproduction in bacteria.
• Example: Rhodomicrobium vannielii

12. Reproduction through cyst formation
• Cysts are formed by the deposition of
additional layers around the mother cell and
are the resting structure during unfavorable
conditions.
• When conditions are favorable again, the
mother cell behaves like its normal self again.
• Example: Azotobacter

14. Reproduction through endospore
formation
• Endospores in a bacterial cell are formed during
stressful conditions such as desiccation and
starvation.
• They contain a central protoplast, and a core
consisting of DNA, ribosomes, enzymes and the t-
RNA, everything necessary for the formation of a
new cell.
• Only one endospore is formed in one bacterial
cell and on germination, it gives rise to a new
bacterial cell.

16. Sexual Reproduction
• However, in asexual reproduction, genetic
recombination is not observed and that is why sexual
reproduction has high significance in the continuation
of a bacterial species. This is because, in sexual
reproduction, genetic material is exchanged between
two cells and which facilitates genetic recombination
and creates a genetic drift in the species of a bacteria.
There are 3 ways bacteria reproduce sexually, these
are:
1. Transformation
2. Transduction
3. Conjugation

17. Transformation
• In transformation, a bacterium takes up DNA
from its environment and often DNA that’s been
shed by another bacteria.
• The phenomenon was first discovered by Griffith
in 1928 and the mechanism was worked out by
Avery in 1944.
• In this process, the DNA of a capsulated bacteria
is transferred into a non-capsulated bacteria. If
the DNA is circular it is called a plasmid.
• The plasmid can be copied in the receiving cell
and passed on to its descendants.

19. Transduction
• In this type of sexual reproduction of bacteria, foreign
genes are transferred into a bacterial cell with the help
of a virus. These viruses are called bacteriophage and
they are not virulent.
• The virus acts as a carrier vehicle and passes over
genes from one host to another. Transducing
bacteriophages may carry the same genes in which the
reproduction method would be known as restricted
transduction. They can also carry different genes at
different times in which the reproduction process
would be known as generalised transduction.

21. Conjugation
• This process was first discovered in Escherichia coli by Tatum and Lederberg in
1946. They found that two different types of nutritional mutants grown together
on minimal medium produced an occasional wild type.
• Bacteria that show conjugation are dimorphic, meaning that they have two types
of cells, one male (F+) or donor cell and a female (F-) or recipient cell.
• The male or donor cell possesses 1 to 4 sex pili on the surface and fertility factor
(transfer factor, sex factor) in its plasmid. It contains genes for producing sex pili
and other characters needed for gene transfer. Sex pili are 1to 4 narrow
protoplasmic outgrowths. The sex pili and fertility factor are absent from the
female or recipient cells.
• If these two types of cells happen to come nearer, a pilus of a male cell establishes
a protoplasmic bridge or conjugation tube with the female cell. It takes 6-8
minutes for the process to complete.
• These were the three types of sexual reproduction in bacteria and it introduces
genetic variation in a bacterial species which is important for the survival of any
species and allows groups to adapt to environmental changes.

23. Thank you
Submitted to Prof Niaz sb