%0 Journal Article %A Hopwood, David A. %A Wright, Helen M. %T Factors Affecting Recombinant Frequency in Protoplast Fusions of Streptomyces coelicolor %D 1979 %J Microbiology, %V 111 %N 1 %P 137-143 %@ 1465-2080 %R https://doi.org/10.1099/00221287-111-1-137 %I Microbiology Society, %X The optimum concentration of polyethylene glycol 1000 (PEG) for the production of recombinants through protoplast fusion in Streptomyces coelicolor was about 50% (w/v). The addition of 14% (v/v) dimethyl sulphoxide to the fusion mixture enhanced recombination frequencies, but only at sub-optimal PEG concentrations. After treatment of protoplasts with 50% PEG for 1 min, the frequency of recombinants in a multi-factor ‘cross’ sometimes exceeded 20% of the total progeny. The frequency of recombinants in the progeny could be significantly enhanced by ultraviolet irradiation of the parental protoplast suspensions immediately before fusion. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-111-1-137