Bacteriophage cycle phages production that infected bacteria, playing a critical role in microbiology. They are lytic& temperate with different life cycles and production methods. Phages production of several keys production. Understanding the drivers structures features and life in found for cycles biotechnology phages therapy and genetic reasearch into bacteriophage. Into viral behaviour for into interaction with bacteriophage host...Bacteriophage cycle phages production that infected bacteria, playing a critical role in microbiology. They are lytic& temperate with different life cycles and production methods. Phages production of several keys production. Understanding the drivers structures features and life in found for cycles biotechnology phages therapy and genetic reasearch into bacteriophage. Into viral behaviour for into interaction with bacteriophage host...Bacteriophage cycle phages production that infected bacteria, playing a critical role in microbiology. They are lytic& temperate with different life cycles and production methods. Phages production of several keys production. Understanding the drivers structures features and life in found for cycles biotechnology phages therapy and genetic reasearch into bacteriophage. Into viral behaviour for into interaction with bacteriophage host...Bacteriophage cycle phages production that infected bacteria, playing a critical role in microbiology. They are lytic& temperate with different life cycles and production methods. Phages production of several keys production. Understanding the drivers structures features and life in found for cycles biotechnology phages therapy and genetic reasearch into bacteriophage. Into viral behaviour for into interaction with bacteriophage host...Bacteriophage cycle phages production that infected bacteria, playing a critical role in microbiology. They are lytic& temperate with different life cycles and production methods. Phages production of several keys production. Understanding the drivers structures features and life in found for cycles biotechnology phages therapy and genetic reasearch into bacteriophage. Into viral behaviour for into interaction with bacteriophage host...Bacteriophage cycle phages production that infected bacteria, playing a critical role in microbiology. They are lytic& temperate with different life cycles and production methods. Phages production of several keys production. Understanding the drivers structures features and life in found for cycles biotechnology phages therapy and genetic reasearch into bacteriophage. Into viral behaviour for into interaction with bacteriophage host...Bacteriophage cycle phages production that infected bacteria, playing a critical role in microbiology. They are lytic& temperate with different life cycles and production methods. Phages production of several keys production. Understanding the drivers structures features and life in found for cycles biotechnology phages therapy and genetic reasearch.

2. Bacteriophages: Structural Organization
life cycle and phages production
Submitted by
ASWINI.V
I MSC MICROBIOLOGY
Sri paramakalyani college
Alwarkurichi

3. Introduction to
Bacteriophages
 Bacteriophages are viruses that infect bacteria, playing a
critical role in microbiology.
 They can be lytic or temperate, with different life cycles and
production methods.
 This presentation will explore the structural organization,life
cycle, and phage production of several key bacteriophages.

4. Structural
Organization of
Bacteriophages
 Phages consist of DNA or RNA (dsDNA or ssDNA) , which can
be linear or circular.
 Structure: 1) Capsid: Protein shell protecting the viral genome.
2) Tall fibers: Help the phage attach to the host.
3) Genome: The DNA or RNA that carries the viral
information.

5. X 174 Phage
ɸ
 Genome: Circular ssDNA (~5,375 nucleotides).
 Capsid: Icosahedral symmetry composed of 60 protein subunits.
 Attachment Protein: Binds to E.coli receptors.
 Life cycle:
* Follows a lytic cycle: After injection of ssDNA, the hosts machinery
replicates the viral DNA via rolling – circle replication.
* New phages are assembled and released upon host lysis.

6. M13 Phage
 Genome: Single- stranded DNA(ssDNA), circular.
 Capsid: Forms a filamentous shape.
 Attachment: Binds to E.coli pilus.
 Life cycle:
* Follows a non-lytic cycle, where new phages are
continuously produced and released via extrusion.
*The host cell remains alive throughout this process.

7. MU Phage
 Genome: Double – stranded DNA (ssDNA) , integrates into the
bacteria chromosomes.
 Life cycle:
* can enter life lysogenic cycle (integrates into host
genome as a prophage).
* can shift to the lytic cycle, producing new phages by
rolling- circle replication, leading to cell lysis.

8. T4 Phage
 Genome: Double – stranded DNA(dsDNA).
 Capsid: Icosahedral shape with a tail structure.
 Life cycle:
* Follows a lytic cycle.
* After attaching to the bacterial cell, the phage injects
DNA, uses rolling – circle replication for genome replication,
and assembled new phages.
* The cell bursts, releasing hundreds of new virions.

9. Lambda Phage
 Genome: Double – stranded DNA (dsDNA ).
 Life cycle:
* Lysogenic cycle: Lambda integrates into the host
genome as a prophase and replicates with the hosts DNA.
* Lytic cycle: If induced, the prophage excises itself,
undergoes rolling- circle replication, assembles new virions, and
cause lysis.

10. Pi Phage
 Genome: Double – stranded DNA (dsDNA ).
 Life cycle:
* Primarily follows the lysogenic cycle, integrating into
the host genome.
* Under certain conditions, it can enter the lytic cycle,
replicating and producing new phages, leading to host cell lysis.

11. Comparison of
Phages
 ɸX 174: Small, ssDNA, lytic cycle.
 M13: ssDNA, non-lytic cycle.
 MU: dsDNA, temperate, lysogenic and lytic cycles.
 T4: dsDNA, lytic cycle.
 Lambda: dsDNA, temperate, lysogenic and lytic cycles.
 Pi: dsDNA, temperate, lysogenic and lytic cycles.

12. Phage Production
Methods
 Phages follow different Production methods based on their life
cycle:
* Lytic cycle: Phages replicate rapidly, leading to cell
lysis and release of progeny phages.
* Lysogenic cycle: Some phages integrate into the host
genome and replicate with the host, producing new phages only
when induced.

13. Conclusion
 Bacteriophages have diverse structural features and life cycles.
 Understanding their production methods is essential for their
application in biotechnology, phage therapy, and genetic
research.
 Each phage type offers unique insights into viral behavior and
interaction with bacterial hosts.

14. THANKYOU