Secondary metabolism, genetic engineering

Volume 28 Genetic Engineering of Plant Secondary Metabolism Proceedings of the Thirty-third Annual Meeting of the Phytochemical Society of North America, Pacific Grove, California, June-July, 1993... 

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. 

The various strategies followed to obtain high producing cell lines will be briefly discussed separately (see Section II). The economics of a plant cell culture production process are discussed below (see Section III). For cell lines that do not produce, it will be necessary to learn more about the regulation of secondary metabolism in order to eventually be able to use genetic engineering for improving production (see below). 

Robins, R. J., Walton, N. J., Parr, A. J., Aird, E. H., Rhodes, J. C., and Hamill, J. D. (1994) Progress in the genetic engineering of the pyridine and tropane alkaloid biosynthetic pathways of Solanaceous plants. In Genetic Engineering of Plant Secondary Metabolism, pp. 1-33, Plenum Press, New York. 

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