Presented by: 1. Sulov Saha 2. Mehedi Hasan

Strain Improvement throughGenetic Engineering

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?

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.

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

Strategies for Strain Improvement through Genetic Engineering

1. Sources of DNA 2. Vector

3. Hosts 4. Metabolic Engineering

Mechanism

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

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)

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

Case Study (cont.)

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.

Recombinant DNA methods have been especially useful in the production of primary metabolites such as amino acids,but are also finding increasing use instrain 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