Department of Microbiology, George S. Wise Center of Life Sciences, Tel Aviv University, Ramat Aviv, Israel.
Biotechnol Bioeng. 1982 Feb;24(2):281-92. doi: 10.1002/bit.260240203.
Emulsan is a polymeric extracellular emulsifying agent produced by Acinetobacter RAG-1. Hydrocarbon-in-water emulsions (V(f) of hydrocarbon of 0.01-0.10) were stabilized by small quantities of emulsan (0.02-0.2 mg/mL). Although both aliphatic and aromatic hydrocarbon emulsions were stabilized by emulsan, mixtures containing both aliphatics and aromatics were better substrates for emulsan than the individual hydrocarbon by themselves. The emulsan remained tightly bound to the hydrocarbon even after centrifugation as determined by (a) residual emulsan in the aqueous phase and (b) the fact that the resulting "cream" readily dispersed in water to reform stable emulsions. With hexadecane-to-emulsan weight ratio of 39 and 155, the noncoalescing oil droplets had average droplet diameters of 2.0 and 4.0 microm, respectively. Dialysis studies showed that the water-soluble dye Rhodamine B adsorbed tightly to the interface of hexadecane-emulsan droplets although the dye did not bind to either hexadecane or emulsan alone. At saturating concentrations of dye, 2.2 micromol of dye were bound per mg emulsan.
乳化剂是一种由不动杆菌 RAG-1 产生的高分子细胞外乳化剂。在少量乳化剂（0.02-0.2mg/ml）的作用下，可以稳定水包油型乳液（烃的 V(f)为 0.01-0.10）。虽然乳化剂可以稳定脂肪烃和芳香烃乳液，但含有脂肪烃和芳香烃的混合物比单独的烃更适合作为乳化剂的底物。通过（a）水相中的残留乳化剂和（b）所得“奶油”在水中极易分散以形成稳定乳液的事实，可以确定乳化剂在离心后仍紧密结合在烃上。在十六烷-乳化剂重量比为 39 和 155 的情况下，非聚结油滴的平均粒径分别为 2.0 和 4.0 微米。透析研究表明，尽管染料罗丹明 B 本身不与十六烷或乳化剂结合，但它可以紧密吸附在十六烷-乳化剂液滴的界面上。在染料的饱和浓度下，每毫克乳化剂结合 2.2 微摩尔的染料。
