Book Viewer

Short Contents | Full Contents | Other books @ NCBI

| Modern Genetic Analysis Chapter 11. Applications of Recombinant DNA Technology Expressing Eukaryotic Genes in Bacteria Figure 11-8. Genetically engineered bacteria. This figure shows how new antibiotics can be synthesized by genetically engineered bacteria. Different species of Streptomycesproduce related but different antibiotics. One species produces actinorhodin, which is blue at alkaline pH. A second species produces medermycin, which is brown. When the genes from the second species were cloned and transformed on a plasmid into the first species, some of the transformed bacteria had acquired the capacity to synthesize a new antibiotic, mederrhodin A, which gives a reddish-purple color. The structures of the three compounds are shown here, together with the streaks of the bacteria synthesizing each of the three compounds. The new antibiotic, mederrhodin A, is similar to medermycin but carries a hydroxyl group at the 6 position. The cloned segment probably contains a gene that encodes a hydrolyase that is expressed when transformed into a different species. (Mervyn J. Bibb, John Innes Institute, United Kingdom)

© 1999 by W. H. Freeman and Company. All rights reserved.