Introduction
Trichoderma Reesei is a mesophilic fungus which is usually known for its high ability to secrete cellulotytic enzymes (Hi138, 2006). It is majorly used in many industrial processes especially in the conversion of cellulose to glucose, large scale fermentation, down strain process engineering and the process of developing genetically modified strains. Cellulase which is also a resultant product of the genetic transformation of Trichoderma Reesei is the most common by-product and Hi138 (2006) identifies that: “Cellulase is widely used in starch processing, grain alcohol, fermentation, preparation and brewing malt, animal breeding, as well as silage beverage processing, fruit juice and vegetable juice extraction and many other areas.” Recent scientific developments have increased the commercial value of Trichoderma Reesei for cellulose hydrolysis.
Genetic Transformation Techniques
Trichoderma Reesei in its natural form does not have high components of protein (which is the most important element of its use). This has led to the massive genetic transformation of the spontaneous strain. Genetic modification is done through molecular transformation techniques and fungal gene transfer (Kinghorn, 1992, p. 184). Genetic transformation systems have also been developed over the past few years to incorporate ascomycetous and basidiomycetous fungi which have eased the process of producing proteins for industrial purposes. This process is also used in food and biological control processes. The same transformation has also been carried out in gilled basidiomycetes (Goldman, Van-Montagu and Herrera-Estrella, 1990).
There have been many methods of universal genetic transformation and common among them is the polyethylene glycol mediated DNA uptake by protoplasts (Goldman, Van-Montagu and Herrera-Estrella, 1990). Other methods such as the electroporation of protoplasts and incubation of germinating conidia in a lithium salt have also existed in the past. The revolution still goes on because recent techniques such as microprojectile bombardment of intact conidia with gold or tungsten particles coated with DNA have been introduced in the recent past; together with the biolistic method which has been practiced more with uninucleate haploid conidia (Goldman, Van-Montagu and Herrera-Estrella, 1990).
These techniques have been proved to have a high rate of success especially in relation to the time required in doing repetitive purification. In addition, these methods have a high record of providing highly stable transformants (Goldman, Van-Montagu and Herrera-Estrella, 1990). Genetic transformation has even had a higher success rate in the recent past with the introduction of Agrobacterium T-DNA which has the highest rate of fungal transformation in relation to fungal conidia.
These methods have been especially developed with a high success rate because of Trichoderma reesei’s high protein synthesis ability. The eukaryotic synthesis mechanism is almost similar to the mammalian protein synthesis system. With high success rates of genetic transformation on Trichoderma reesei, studies have been done to probe its safety. Results have established that the system is very safe (Hi138, 2006).
Conclusion
Among the existing methods of genetic transformation of Trichoderma reesei, a modification of the initial processes has especially increased protein production. The use of genes is especially noteworthy. The presence of Trichoderma reesei in a number of molecular systems and adoption of different strategies for the homologous and heterologous protein production forms can significantly improve production. With the nature of Trichoderma Reesei, while carrying out genetic engineering modification, the commercial viability of making a variety of commercially viable strains is highly likely. The mass production of genetically transformed strains of Trichoderma reesei will improve and even be more efficient in the near future.
References
Goldman, G.H., Van Montagu, M., & Herrera-Estrella, A. (1990). Transformation of Trichoderma harzianum by high-voltage electric pulse. Curr. Genet, 17, 169-174.
Hi138. (2006). Filamentous Fungus Trichoderma Reesei the Production Of Recombinant Proteins in Molecular Biology Research. Web.
Kinghorn, J. (1992). Applied Molecular Genetics Of Filamentous Fungi. New York: Springer.