Ionophorous and sequestering properties of surfactin, a biosurfactant from Bacillus subtilis

✍ Scribed by Laurence Thimon; Françoise Peypoux; Jean Wallach; Georges Michel

• Book ID: 103967599
• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 485 KB
• Volume: 1
• Category: Article
• ISSN: 0927-7765
• DOI: 10.1016/0927-7765(93)80018-t

✦ Synopsis

Surfactm ~b a bacterial hpopeptlde containmg two carboxyhc groups Its sequestermg propertles (surfactln bmds calcium and magnesium Ions) were determmed III aqueous solution at pH 9.5. The calculated assoclatlon constants were k'zl.5

x IO5 Mm' for Ca2* and 1.9 x IO' M-' for Mg". Its complexmg propertles were determined by the two-phase dlatrlbutlon system: the aqueous phase contamed Ca2+ or Rb' Ions and the hpldlc phase contamed surfactm. At pH 9. surfactm forms a I 1 complex with Ca" and a 2 I complex with Rb' and it shows a higher affimty for dlvalent catlons than for monovalent catlons Surfactln IS non-selective m bmdmg monovalent catlons but 1s shghtly more effective m bindmg Ca'+ than Mg'or Ba'-. Surfactm IS also a moblle carrier to transport monovalent and dlvalent cations across a solvent barrier and medlatea the exchange between H-and morganic catlon.