Interspecific recombination among aminoglycoside producing streptomycetes

From auxotrophic double mutants of Streptomyces rimosus forma paromomycinus and Streptomyces kanamycerticus producing little or no antibiotic, stable prototrophic recombinants were obtained with low frequencies. Most of the recombinants differed from the parents in morphology and antibiotic production. The most frequent classes of recombinants behaved as streptomycetes of the "red" series and produced a wide range of neomycin yields, in contrast to the parents which produced paromomycin and a small proportion of neomycin, or kanamycin, respectively. Hypotheses on the nature of the genetic material exchanged are discussed.