Metabolic and regulatory engineering of Serratia marcescens: mimicking phage-mediated horizontal acquisition of antibiotic biosynthesis and quorum-sensing capacities.

Serratia marcescens is an important cause of opportunistic human infections. Many, but not all, strains produce prodigiosin, a secondary metabolic, red-pigment antibiotic, the biosynthesis of which is directed by the pig gene cluster. Quorum sensing (QS) involves the production and detection of chemical signal molecules as a means to regulate gene expression in response to population cell density.

The Serratia gene cluster encoding biosynthesis of the red antibiotic, prodigiosin, shows species- and strain-dependent genome context variation.

The prodigiosin biosynthesis gene cluster (pig cluster) from two strains of Serratia (S. marcescens ATCC 274 and Serratia sp. ATCC 39006) has been cloned, sequenced and expressed in heterologous hosts.

The regulation of virulence in phytopathogenic Erwinia species: quorum sensing, antibiotics and ecological considerations.

Erwinia carotovora is a Gram-negative bacterial phytopathogen that causes soft-rot disease and potato blackleg. The organism is environmentally widespread and exhibits an opportunistic plant pathogenesis. The ability to secrete multiple plant cell wall-degrading enzymes is a key virulence trait and exoenzyme production is responsive to multiple environmental and physiological cues.