title: Emulsan in Acinetobacter calcoaceticus RAG-1: Distribution of Cell-Free and Cell-Associated Cross-Reacting Material.
abstract: Emulsan is an extracellular polymeric bioemulsifier produced by Acinetobacter calcoaceticus RAG-1. Antibodies prepared against purified emulsan inhibited the activity of the polymer in a standard emulsification test. These antibodies were used to develop a sensitive enzyme-linked immunosorbent assay to monitor changes in cell-free emulsan throughout the growth cycle. This assay was also used to detect emulsan associated with the cell surface and to monitor changes in the distribution of cell-free and cell-associated emulsan throughout the growth cycle. Cells in the early exponential phase exhibited relatively large amounts of cell-associated emulsan which decreased rapidly between the midexponential and early stationary phases. This drop in cell-associated material was accompanied by a rise in the concentration of extracellular polymer. Moreover, in agreement with previous results (C. Rubinovitz, D. L. Gutnick, and E. Rosenberg, manuscript in press), production of cell-free emulsan was enhanced in the presence of chloramphenicol. The release of this material from the cell surface in the presence of chloramphenicol apparently involved the synthesis of cell-associated cross-reacting material since the relative amount of such cell-bound polymer remained constant during the treatment with the drug.
authors.affiliation: Department of Microbiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: S
authors.initials: S
authors.lastname: Goldman
authors.forename: Y
authors.initials: Y
authors.lastname: Shabtai
authors.forename: C
authors.initials: C
authors.lastname: Rubinovitz
authors.forename: E
authors.initials: E
authors.lastname: Rosenberg
authors.forename: D L
authors.initials: DL
authors.lastname: Gutnick