Kaplan N, Zosim Z, Rosenberg E
Appl Environ Microbiol. 1987 Feb;53(2):440-6. doi: 10.1128/aem.53.2.440-446.1987.
Acinetobacter calcoaceticus BD4 and BD413 produce extracellular emulsifying agents when grown on 2% ethanol medium. For emulsifying activity, both polysaccharide and protein fractions were required, as demonstrated by selective digestion of the polysaccharide with a specific bacteriophage-borne polysaccharide depolymerase, deproteinization of the extracellular emulsifying complex with hot phenol, and reconstitution of emulsifier activity with pure polysaccharide and a polysaccharide-free protein fraction. Chemical modification of the carboxyl groups in the polysaccharide resulted in a loss of activity. The protein required for reconstitution of emulsifying activity was purified sevenfold. The BD4 emulsan apparently derives its amphipathic properties from the association of an anionic hydrophilic polysaccharide with proteins.
醋酸钙不动杆菌BD4和BD413在2%乙醇培养基上生长时会产生细胞外乳化剂。对于乳化活性而言，多糖和蛋白质组分都是必需的，这通过用特定噬菌体携带的多糖解聚酶对多糖进行选择性消化、用热酚对细胞外乳化复合物进行脱蛋白处理以及用纯多糖和无多糖的蛋白质组分重建乳化剂活性得以证明。多糖中羧基的化学修饰导致活性丧失。重建乳化活性所需的蛋白质被纯化了7倍。BD4乳化剂显然是通过阴离子亲水性多糖与蛋白质的结合而获得其两亲性特性的。
