used to characterize biosurfactants. The collected precipitate containing the
biosurfactant is dissolved in 10 ml of sterile distilled water and dialyzed further
with double distilled water for 48 h at 10
C, in dialysis and lyophilization method, at
4
C in an airtight container; the dialysate is stored for further use (Satpute et al.
2010a).
4.7.3 Biosurfactant Characterization
There are several spectroscopic and chromatography methods used for the characterization of biosurfactants, i.e., Fourier transform infrared spectroscopy (FT-IR),
nuclear magnetic resonance (NMR), thin-layer chromatography (TLC), and highperformance liquid chromatography (HPLC), etc. (Fig. 1.6).
FT-IR and NMR spectroscopic methods. Based on functional groups, FT-IR can
explain some components of an unknown mixture (Elazzazy et al. 2015; Antoniou
et al. 2015). NMR gives information related to the functional groups about the
position of linkages within the carbohydrate molecules and lipids due to transitions
in atoms with a magnetic moment when an external magnetic field is applied.
Fig. 1.5 Various available extraction methods for biosurfactant from microbes
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K. Mulugeta et al.