Alginate Synthesis in Mucoid Pseudomonas aeruginosa: a Chromosomal Locus Involved in Control

Department of Bacteriology, University of Edinburgh, Medical School, Teviot Place, Edinburgh EH8 9AG ABSTRACT Summary: Mucoid variants of Pseudomonas aeruginosa isolated in vitro or in vivo could be classified into two phenotypic groups based on whether alginate was produced on a chemically defined medium. Mucoid strains yielded lower recombination frequencies than the non-mucoid parent when used as donors in FP2-mediated plate matings. The mucoid characteristic ( muc ) was co-inherited by a proportion of recombinants selected for the inheritance of chromosomal markers his-5075 + or cys-5605 + . The results of further experiments using either a mucoid recipient or a mucoid donor carrying plasmid R68.45 suggested that the control of alginate production in P. aeruginosa involves at least one chromosomal locus.