Tolerance of Acinetobacter calcoaceticus RAG-1 to the cationic surfactant cetyltrimethylammonium bromide: role of the bioemulsifier emulsan.
Emulsan, the polyanionic heteropolysaccharide bioemulsifier produced by Acinetobacter calcoaceticus RAG-1, was found to enhance the tolerance of RAG-1 cells to the toxic effects of the cationic detergent cetyltrimethylammonium bromide (CTAB). Emulsan-mediated tolerance was obtained with the purified deproteinated apoemulsan; ca. 9 micrograms of apoemulsan neutralized 1 microgram of CTAB. Deesterified apoemulsan was only half as effective in protecting the cells from CTAB toxicity. Tolerance was also mediated by the cell-associated emulsan minicapsule. Mutants lacking this capsule were more sensitive to CTAB than the corresponding parent. The growth of mutants and parent cells in mixed-culture experiments demonstrated that the cell-associated polymer mediates CTAB tolerance in the early stages of growth. Once sufficient cell-free polymer has been released into the aqueous medium (ca. 0.5 micrograms/ml), this extracellular emulsan also plays a role in CTAB tolerance.
D000150:Acinetobacter / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology*; D003470:Culture Media; D009154:Mutation; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis / Q000494:pharmacology*; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*
D000891:Anti-Infective Agents, Local; D002593:Cetrimonium Compounds; D003470:Culture Media; D011135:Polysaccharides, Bacterial; D000644:Quaternary Ammonium Compounds; C036028:emulsan; D000077286:Cetrimonium