ber die biogenese von aromastoffen bei pflanzen und fr�chten

Advances on (+)-nootkatone microbial biosynthesis and its related enzymes

(+)-Nootkatone is an important functional sesquiterpene and is comprehensively used in pharmaceutical, cosmetic, agricultural and food flavor industries. However, (+)-nootkatone is accumulated trace amounts in plants, and the demand for industry is mainly met by chemical methods which is harmful to the environment. The oxygen-containing sesquiterpenes prepared using microbial methods can be considered as "natural." Microbial transformation has the advantages of mild reaction conditions, high efficiency, environmental protection, and strong stereoselectivity, and has become an important method for the production of natural spices. The microbial biosynthesis of (+)-nootkatone from the main precursor (+)-valencene is summarized in this paper. Whole-cell systems of fungi, bacteria, microalgae, and plant cells have been employed. It was described that the enzymes involved in the microbial biosynthesis of (+)-nootkatone, including cytochrome p450 enzymes, laccase, lipoxygenase, and so on. More recently, the related enzymes were expressed in microbial hosts to heterologous produce (+)-nootkatone, such as Escherichia coli, Pichia pastoris, Yarrowia lipolytica, and Saccharomyces cerevisiae. Finally, the development direction of research for realizing industrialization of microbial transformation was summarized and it provided many options for future improved bioprocesses.

[Recent developments in selected areas of food biotechnology]

With respect to literature and own experiments a review is given of the current international knowledge in special fields of food biotechnology. In this context nutritionally and physiologically relevant problems find particular consideration. After an introduction the development in technology, genetic engineering and protein technology is discussed. Then the following topics are dealt with: Single cell proteins (mushrooms, yeasts, bacteria, fungi, phototrophic microorganisms), soluble enzymes, enzyme inhibitors, immobilized systems (enzymes, cells, new processes and products), amino acids, sweeteners, microbial polysaccharides as hydrocolloids, organic edible acids, plant cell and tissue cultures and flavourings (enzymes, microorganisms, plant systems).