Shoham Y, Rosenberg M, Rosenberg E
Appl Environ Microbiol. 1983 Sep;46(3):573-9. doi: 10.1128/aem.46.3.573-579.1983.
Emulsan is a polyanionic heteropolysaccharide bioemulsifier produced by Acinetobacter calcoaceticus RAG-1. A mixed bacterial population was obtained by enrichment culture that was capable of degrading emulsan and using it as a carbon source. From this mixed culture, an emulsan-degrading bacterium, termed YUV-1, was isolated. Strain YUV-1 is an aerobic, gram-negative, non-spore-forming, rod-shaped bacterium which grows best in media containing yeast extract. When placed on preformed lawns of A. calcoaceticus RAG-1, strain YUV-1 produced translucent plaques which grew in size until the entire plate was covered. Plaque formation was due to solubilization of the emulsan capsule of RAG-1. Plaque formation was not observed on emulsan-negative mutants of RAG-1. As a consequence of the solubilization of the emulsan capsule, RAG-1 cells became more hydrophobic, as determined by adherence to hexadecane. Growth of YUV-1 on a medium containing yeast extract and emulsan was biphasic. During the initial 24 h, cell concentration increased 10-fold, but emulsan was not degraded; during the lag in growth (24 to 48 h), emulsan was inactivated and depolymerized but not consumed; during the second growth phase (48 to 70 h) the depolymerized emulsan products were consumed.
乳化素是一种由醋酸钙不动杆菌RAG-1产生的聚阴离子杂多糖生物乳化剂。通过富集培养获得了一个能够降解乳化素并将其用作碳源的混合细菌群体。从这个混合培养物中分离出了一种名为YUV-1的乳化素降解细菌。菌株YUV-1是一种需氧、革兰氏阴性、不形成芽孢的杆状细菌，在含有酵母提取物的培养基中生长最佳。当将其放置在醋酸钙不动杆菌RAG-1预先形成的菌苔上时，菌株YUV-1产生半透明噬菌斑，噬菌斑大小不断增大，直到覆盖整个平板。噬菌斑的形成是由于RAG-1的乳化素荚膜溶解。在RAG-1的乳化素阴性突变体上未观察到噬菌斑形成。由于乳化素荚膜的溶解，通过对十六烷的粘附测定，RAG-1细胞变得更疏水。YUV-1在含有酵母提取物和乳化素的培养基上的生长是双相的。在最初的24小时内，细胞浓度增加了10倍，但乳化素未被降解；在生长停滞期（24至48小时），乳化素被灭活和解聚，但未被消耗；在第二个生长阶段（48至70小时），解聚的乳化素产物被消耗。
