PRODUCTION OF CAROTENOIDS BY RECOMBINANT-DNA TECHNOLOGY

Biotechnology can be used to effect the production of carotenoids by natural organisms. Algae and yeast strains have been developed by classical strain improvement methods to produce several different carotenoids. However, the carotenoid productivity of these organisms is low compared to carotenoid production by chemical synthesis. One way to increase the production of carotenoids in biological systems is to use recombinant DNA techniques. The carotenoid biosynthetic pathway is especially amenable to manipulation by recombinant DNA techniques since all carotenoids share a common precursor. Effecting these key steps with genetic engineering methods can increase carotenoid productivity. In addition natural systems have a very widespread biosynthetic capability, and these systems can be used to synthesize novel carotenoids for particular applications. Recently, many genes coding for enzymes catalyzing specific steps in the biosynthesis of carotenoids have been isolated and characterized from bacteria, cyanobacteria, and higher plants. This paper will focus on the application of carotenoid biosynthetic genes to affect carotenoid production in bacteria and yeasts.