Genetically manipulated fungi Flashcards
intro
Fungi are highly versatile organisms with a rich history of use in biotechnology, especially for the production of commercially valuable products such as enzymes, pharmaceuticals, and biofuels. Genetic manipulation of fungi enables the optimization of these processes and enhances the yields of desired products. This can be achieved through a variety of techniques that involve manipulating the fungal genome, utilizing molecular tools, and employing metabolic engineering strategies.
First para - transformation system
One of the fundamental steps in fungal genetic manipulation is the introduction of foreign DNA into the fungal genome, typically via transformation. There are several methods of transformation, including protoplast-mediated transformation, electroporation, and Agrobacterium-mediated transformation. Protoplast transformation involves the removal of the fungal cell wall, making the cells susceptible to DNA uptake (Barker et al., 2017). Electroporation, on the other hand, uses an electrical field to induce the uptake of plasmid DNA into fungal cells, and is widely used in species such as Aspergillus and Neurospora crassa.
For example, in Aspergillus niger, a commonly used industrial fungus, transformation systems have been developed to express heterologous genes that produce enzymes like cellulases and xylanases, which are used in biofuel production (Barker et al., 2017). Transformation in Aspergillus can lead to strains with improved product yields, such as the engineered strains that produce high levels of glucoamylase for starch hydrolysis in industrial settings.
Second para - target genes
Overexpression systems are widely used to increase the production of enzymes or proteins of interest. This is typically achieved by introducing extra copies of the gene or using strong promoters to drive high levels of expression. For example, the production of fungal cellulases and hemicellulases in Trichoderma reesei, a well-known producer of enzymes for biofuel production, can be optimized by overexpressing genes encoding the catalytic enzymes. Strong promoters, such as the cbh1 promoter, can drive high levels of expression in engineered Trichoderma strains, resulting in increased enzyme yields for the breakdown of plant biomass (Albers et al., 2020).
Third para - synthetic biology approach
Synthetic biology integrates genetic manipulation with systems biology to design and construct new biological parts and systems that do not naturally exist in organisms. This can include the creation of novel pathways for the biosynthesis of valuable chemicals. In fungi, synthetic biology tools are used to construct synthetic biosynthetic pathways to produce rare or non-natural compounds.
An example of synthetic biology applied to fungal systems is the use of engineered Saccharomyces cerevisiae strains for the production of terpenoids, which have applications in pharmaceuticals, flavoring, and fragrance industries. By introducing foreign genes encoding enzymes for the mevalonate pathway, researchers have engineered yeast strains capable of producing high yields of terpenoids like artemisinin, an anti-malarial drug precursor (Barker et al., 2017).
conc
Fungi are powerful hosts for the production of commercially valuable products, and genetic manipulation plays a critical role in enhancing the efficiency and scalability of these production processes. Techniques such as transformation, gene disruption, overexpression, metabolic engineering, and synthetic biology have enabled the optimization of fungal strains for a range of applications, from biofuel production to pharmaceuticals. The ability to engineer fungal strains for the production of high-value metabolites continues to offer significant opportunities for industrial biotechnology.
