The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
Curr Microbiol. 2010 Aug;61(2):112-7. doi: 10.1007/s00284-010-9584-7. Epub 2010 Feb 5.
Isolate A-3 from Antarctic soil in Casey Station, Wilkes Land, was characterized for growth on hydrocarbons. Use of glucose or kerosene as a sole carbon source in the culture medium favoured biosynthesis of surfactant which, by thin-layer chromatography, indicated the formation of a rhamnose-containing glycolipid. This compound lowered the surface tension at the air/water interface to 27 mN/m as well as inhibited the growth of B. subtilis ATCC 6633 and exhibited hemolytic activity. A highly hydrophobic surface of the cells suggests that uptake occurs via a direct cell-hydrocarbon substrate contact. Strain A-3 is Gram-positive, halotolerant, catalase positive, urease negative and has rod-coccus shape. Its cell walls contained meso-diaminopimelic acid. Phylogenetic analysis based on comparative analysis of 16S rRNA gene sequences revealed that strain A-3 is closely related to Rhodococcus fascians with which it shares 100% sequence similarity. This is the first report on rhamnose-containing biosurfactant production by Rhodococcus fascians isolated from Antarctic soil.
从南极洲凯西站威克斯地的土壤中分离出的 A-3 菌株，其特点是能够在碳氢化合物上生长。在培养基中使用葡萄糖或煤油作为唯一的碳源有利于表面活性剂的生物合成，通过薄层层析表明形成了一种含有鼠李糖的糖脂。该化合物将气/水界面的表面张力降低至 27 mN/m，同时抑制枯草芽孢杆菌 ATCC 6633 的生长，并表现出溶血活性。细胞具有高度疏水性表面，表明通过直接的细胞-碳氢化合物底物接触进行摄取。A-3 菌株为革兰氏阳性、耐盐、过氧化氢酶阳性、脲酶阴性，呈杆状-球菌状。其细胞壁含有 meso-二氨基庚二酸。基于 16S rRNA 基因序列比较分析的系统发育分析表明，A-3 菌株与节杆菌 fascians 密切相关，两者具有 100%的序列相似性。这是首次报道从南极土壤中分离出的节杆菌 fascians 产生含有鼠李糖的生物表面活性剂。
