1. Presented by: 1. Sulov Saha
2. Mehedi Hasan
Strain Improvement through
Genetic Engineering

2. A strain is a subgroup of a species with one or more
characteristics that distinguish it from other subgroups of the
same species. Each strain is identified by a name, number, or
letter.
For example: L. acidophilus LA-5
What is Strain?

3. Strain Improvement
The science and technology
of manipulating and
improving microbial strains,
in order to enhance their
metabolic capacities for
biotechnological
applications, are referred
to as Strain Improvement.

4. Objectives
to get multiple copies of specific gene
to get high amounts of specific protein or product
to integrate gene of interest of one organism into another

5. Strategies for Strain Improvement
through Genetic Engineering
1. Sources
of DNA
2. Vector
3. Hosts
4. Metabolic
Engineering

6. Mechanism

7. Steps involved
Preparation of desired DNA
Insertion of desired DNA into
vector DNA
Introduction of recombinant
DNAs into host cells
Identification of recombinants
Expression of cloned genes

8. Applications
In the field of
food technology:
production of
recombinant
enzyme
In the field of
agriculture:
recovery of
plant’s characters
In the field of
microbiology:
improve the
microbe’s
productivities or
characteristics
In the industry:
improvement of
industrial strain
(e.g. paper
industry)

9. Also known as rennin
Single polypeptide chain of 323 amino
acids
Main coagulating enzyme found in
rennet which is used extensively in
cheese production.
Increase Chymosin production has
been made through expression of
calf Chymosin gene in recombinant
K. lactis.
Case Study
Chymosin

10. Case Study (cont.)

11. Future Aspects
Industrial
strains
Food
Engineering
System
Biology
Desired
traits
Biodiversity
Strain Improvement
through Genetic
Engineering will
undoubtedly continue as
the knowledge about the
genetic make-up of
microorganisms used for
enzyme production
expands and new genetic
techniques emerge.

12. Recombinant DNA methods have been
especially useful in the production of
primary metabolites such as amino acids,
but are also finding increasing use in
strain development programs for antibiotics.
Current strain improvement strategies have already contributed to
creating more efficient and safer enzyme production strains.
The task of both discovering and improving the new strain of interest
ones have become more and more challenging.
Conclusion