Isolation of Alginate-producing Mutants of Pseudomonas fluorescens, Pseudomonas putida and Pseudomonas mendocina

Spontaneous alginate-producing (muc) variants were isolated from strain of Pseudomonas fluorescens, P. putida and P. mendocina at a frequency of 1 in 10⁸ by selcting for carbenicillin resistance. The infrared spectrum of the bacterial exopolysaccharide was typical of an acetylated alginate similar to that previously described in Azotobacter vinelandil and in mucoid variants of P. aeruginosa. Mucoid variants were not isolated from P. stuteri, P. pseudoalcaligenes, P. testosteroni, P. diminuta, P. acidovorans, P. cepacia or P. maltophilia.