title: Antimicrobial biosurfactants from marine Bacillus circulans: extracellular synthesis and purification.
abstract: OBJECTIVE
  To purify the biosurfactant produced by a marine Bacillus circulans strain and evaluate the improvement in surface and antimicrobial activities.
  
  
  RESULTS
  The study of biosurfactant production by B. circulans was carried out in glucose mineral salts (GMS) medium using high performance thin layer chromatography (HPTLC) for quantitative estimation. The biosurfactant production by this strain was found to be growth-associated showing maximum biosurfactant accumulation at 26 h of fermentation. The crude biosurfactants were purified using gel filtration chromatography with Sephadex G-50 matrix. The purification attained by employing this technique was evident from UV-visible spectroscopy and TLC analysis of crude and purified biosurfactants. The purified biosurfactants showed an increase in surface activity and a decrease in critical micelle concentration values. The antimicrobial action of the biosurfactants was also enhanced after purification.
  
  
  CONCLUSIONS
  The marine B. circulans used in this study produced biosurfactants in a growth-associated manner. High degree of purification could be obtained by using gel filtration chromatography. The purified biosurfactants showed enhanced surface and antimicrobial activities.
  
  
  CONCLUSIONS
  The antimicrobial biosurfactant produced by B. circulans could be effectively purified using gel filtration and can serve as new potential drugs in antimicrobial chemotherapy.
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Kharagpur, West Bengal, India.
authors.forename: S
authors.initials: S
authors.lastname: Mukherjee
authors.forename: P
authors.initials: P
authors.lastname: Das
authors.forename: C
authors.initials: C
authors.lastname: Sivapathasekaran
authors.forename: R
authors.initials: R
authors.lastname: Sen
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism* / Q000494:pharmacology; D001407:Bacillus / Q000145:classification / Q000254:growth & development* / Q000378:metabolism*; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D008826:Microbial Sensitivity Tests; D013056:Spectrophotometry, Ultraviolet; D013501:Surface-Active Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D013501:Surface-Active Agents