Table 2.

Chemical composition data (as determined by XPS) forS. mitis BMS and BA biosurfactants released in the stationary growth phase and for reference compounds

Crude biosurfactant or compoundElemental concn ratiosFractions of carbon and oxygen involved in various chemical functions
Biosurfactant released by:
S. mitisBA0.1720.4070.0190.580.240.1800.3420.065
S. mitisBMS0.1010.4260.0160.640.
Acid-precipitated S. mitis BMS biosurfactant0.0710.3660.0160.610.
Reference compounds
 Proteina 0.2700.3200.410.320.28f 0.2750.045
 Glycosidic residueb 00.83000.830.17f 00.833
 Rhamnolipid R1c 00.40600.560.310.060.060.0610.345
 Rhamnolipid R2c 00.34600.650.
 Phospholipidd 0.0090.210.0340.820.
 LTAe 0.0310.630.0660.410.440.440.100.1510.478
  • a Average protein, calculated based on a collection of bacterial, fungal, and mammalian proteins (21).

  • b Glycosidic residue C6H10O5 (21).

  • c Calculated for rhamnolipids synthesized byPseudomonas aeruginosa. R1 contains two rhamnose units, and R2 contains one rhamnose unit (6, 11).

  • d l-α-Phosphatidyl-dl-glycerol dimyristoyl.

  • e LTA, Lipoteichoic acid from S. mutans (Sigma).

  • f CO and OC—OH together.