7-1.1 Introduction
Microbial biotechnology involves the exploitation, genetic manipulation and alterations of micro-organisms to make commercial valuable products and that also involves fermentationand various upstream and downstream processes.
Microorganisms produce an amazing array of valuable products such as macromolecules (e.g. proteins, nucleic acids, carbohydrate polymers, even cells) or smaller molecules and are usually divided into metabolites that are essential for vegetative growth (primary metabolites) and those which give advantages over adverse environment (secondary metabolites). They usually produce these compounds in small amounts that are needed for their own benefit.
7-1.2 Genetic Engineering of Microorganisms for Biotechnology
Molecular genetics can be used to manipulate genes in order to alter the expression and production of microbial products, including the expression of novel recombinant proteins.
The compounds that are isolated from plants or animals can be synthesized by genetic manipulation of different micro-organisms to enhance the production and by environmental and other manipulations, even up to 1000-fold for small metabolites can be increased.
The advent of recombinant DNA technology (also referred to as gene cloning or in vitro genetic manipulation) has dramatically broadened the spectrum of microbial genetic manipulations. With the advancement of recombinant DNA technology, many novel host systems have been explored to produce commercially important products like therapeutic proteins, antibiotics, small molecules, biosimilars etc.
The basis of this technology is the use of restriction endonucleases, polymerases and DNA ligases as a means to specifically cut and paste fragments of DNA. Similarly, foreign DNA fragments can be introduced into a vector molecule (a plasmid or a bacteriophage), which enables the DNA to replicate after introduction into a bacterial cell.
The ability to modify and clone genes accelerated the rate of discovery and the development in biotech industries.