Generalized transduction in Streptomyces species

The primary objective of this work is to develop a system of generalized transduction in Streptomyces and thereby provide a means of genetic analysis and manipulation to accomplish tasks not possible by available methods. We have isolated broad-host-range phages and demonstrated that these phages are capable of generalized transduction in Streptomyces coelicolor , the model organism for Streptomyces genetics and molecular biology, and other Streptomyces species, including those that produce commercially important antibiotics. Phages that infect S. coelicolor have previously been characterized, but none capable of generalized transduction have been reported. The key to our ability to demonstrate transduction by these phages has been the establishment of conditions that severely reduce superinfection killing during selection of transductants. We suggest that the previous difficulties in finding transducing phages in streptomycetes seem not to be caused by any biological peculiarities of these organisms but probably more by the number of phages tested and the procedures used in assaying transductional ability. Because of the relatively few genetic tools available in Streptomyces, we anticipate that generalized transduction will be even more important to the study of Streptomyces biology than it has been for the study of other eubacteria.; Characterization of the biological and morphological properties of the phages will facilitate further development of their use as genetic tools. Each of the newly isolated phages showed the typically lambdoid shape characteristics of phages based on electron micrographs and range in size from 45 to 120 kb. All phages tested adsorb to a wide range of Streptomyces species, indicating a broad host range. We anticipate that these phages will provide an important genetic tool for the study of morphogenesis and antibiotic production in Streptomyces species.