Genetically engineered microbial system

Components of a Genetically Engineered Microbial Biocontrol System. 

Gene Expression Systems. One of the potentials of genetic engineering of microbes is production of large amounts of recombinant proteias (12,13). This is not a trivial task. Each proteia is unique and the stabiUty of the proteia varies depending on the host. Thus it is not feasible to have a single omnipotent microbial host for the production of all recombinant proteias. Rather, several microbial hosts have to be studied. Expression vectors have to be tailored to the microbe of choice. 

As an outlook, the optimization of the efficiency of microorganisms with methods of genetic engineering will result in an increased sensitivity, selectivity, and stability, in connection with the further miniaturization of biosensor systems, especially the development of portable biosensor measuring devices, represents a promising feature for environmental monitoring by microbial... 

Tailoring Opportunities. There are many methods or approaches available to tailor enzyme products. Early in the history of enzyme companies, methods such as source selection, microbial strain selection, growth conditions, media, purification, and recovery systems, were primarily used to make each enzyme preparation unique. Later, immobilization, encapsulation, and chemical modification of the enzyme molecule itself were added as methods of tailoring enzymes to better fit industrial applications. Today, all of these methods are still being used, and now we have added genetic engineering to our tailoring expertises. 

There has been much work conducted recently in the area of plant cell culture, or phytoproduction, especially where the product is a plant-unique mixture of Individual flavor substances such as vanilla extract of which vanillin is the major component. As well, the possibility of genetically engineering improved varieties of plants for high yield and consistent quality products is of considerable interest especially for more complex plant-unique flavors. Many flavor compounds are secondary metabolites for which a detailed understanding of their production is not well understood. Presently more knowledge exists In microbial metabolism relative to plant biosynthetic pathways and therefore has resulted in more successful development of microbial-based flavor bioprocessing. As well, scale-up of microbial cultures and isolated enzymes has become relatively common practice while the translation of plant cell culture to large commercial scales is not yet well established. This review will focus on the microbial whole cell and isolated enzyme systems for flavor production. 

Genetic engineering enabling expression in microbial systems has been used successfully to produce proteins having annual production requirements of a few tons or less. However, annual production requirements for a therapeutic Hb will likely reach thousands of tons following commercialization. Thus, matching the production capabilities to commercial requirements is a major challenge. 

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