PHYSIOLOGY AND GENETICS OF ANTIBIOTIC PRODUCTION AND RESISTANCE

Actinomycetes have the genetic capability to synthesize many different biologically active secondary metabolites and of these compounds, ant ibiotics predominate in therapeutic and commercial importance. Intensi ve research often centres on the use of molecular techniques to invest igate the physiology and genetics of antibiotic biosynthesis with a vi ew to improving production. The isolation of clones of Streptomyces hy groscopicus, the producer of geldanamycin, which synthesizes geldanamy cin in S. lividans, is reported. Molecular approaches using genes for elongation factors (tuf) were used in attempts to increase the ferment ation yield of kirromycin, whilst probes for aphD and sph, genes for s treptomycin phosphotransferases, were used to gather information on st reptomycin genes in soil. Actinomycete populations in soil and earthwo rms may help in developing a strategy for discovering additional antim icrobials in soil. The relationship of proline metabolism to the secon dary metabolite undecylprodigiosin and the carbon regulation of spiram ycin biosynthesis in S. ambofaciens is also reported.