Influence of deletions in the apoemulsan gene cluster on A. venetianus RAG-1 polysaccharide biosynthesis.

Apoemulsan is a biopolymer with potent emulsification activity, produced by Acinetobacter venetianus RAG-1 (RAG-1). The wee gene cluster is responsible for apoemulsan biosynthesis. The analysis of (i) a putative polysaccharide copolymerase mutant (wzc), (ii) a putative polymerase mutant (wzy), and (iii) an apoemulsan-deficient variant (2) indicated that the wee gene cluster controls the synthesis of two polysaccharides: high molecular weight (HMW) and low molecular weight (LMW).

Modifications and applications of the Acinetobacter venetianus RAG-1 exopolysaccharide, the emulsan complex and its components.

Since its discovery in the late 1970s, emulsan has been the subject of significant interest for fundamental biosynthesis and structure-function relationships as well as for its potential industrial applications. These studies initially examined the emulsification properties of the compound, while more recent efforts have focused on potential biomedical applications. As a result of this change of focus, it became necessary to more completely characterize the structure of the emulsan molecule and to develop a more reproducible purification process.

Discovery of the dual polysaccharide composition of emulsan and the isolation of the emulsion stabilizing component.

Emulsan has been reported as an emulsion stabilizing amphipathic lipoheteropolysaccharide secreted by the oil-degrading bacterium Acinetobacter venetianus RAG-1. Previously, emulsan was regarded as a single polymer. As a result of developing a new purification process, we have discovered that emulsan is a complex of approximately 80% (w/w) lipopolysaccharide (LPS) and 20% (w/w) high molecular weight exopolysaccharide (EPS).