Biosurfactant production by halotolerant Rhodococcus fascians from Casey Station, Wilkes Land, Antarctica.
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.
The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria. teteven@excite.com
Victoria
V
Gesheva
Erko
E
Stackebrandt
Evgenia
E
Vasileva-Tonkova
D000864:Antarctic Regions; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001412:Bacillus subtilis / Q000187:drug effects; D015373:Bacterial Typing Techniques; D002855:Chromatography, Thin Layer; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004912:Erythrocytes / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D006017:Glycolipids / Q000032:analysis; D006461:Hemolysis; D006838:Hydrocarbons / Q000378:metabolism; D007648:Kerosene; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012240:Rhodococcus / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013501:Surface-Active Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D006017:Glycolipids; D006838:Hydrocarbons; D007648:Kerosene; D012336:RNA, Ribosomal, 16S; D013501:Surface-Active Agents; D005947:Glucose