Characterization of sophorolipids from the yeast Starmerella bombicola O-13-1 using waste fried oil and cane molasses as substrates

摘要

In order to reduce the cost of sophorolipids (SLs) production, we selected waste fried oil (WFO) and cane molasses as co-carbon sources for biosynthesis of SLs by the strain O-13-1, identified as Starmerella bombicola. The SLs production yield reached 49.4 +/- 0.7 g/L during shake-flask fermentation period using two carbon sources. The biosurfactant components, identified by liquid chromatography associated with electrospray ionization tandem mass spectrometry, were the mixture homologs of lactonic and acidic SLs of acetylated sophorose binding with octadecanoic, octadecenoic, and octadecadienoic acid moieties. Its critical micelle concentration (36.5 mg/L) and minimum surface tension (34.9 mN/m) were almost similar to those obtained from conventional substrates. The produced SLs possessed high emulsification activity toward various hydrophobic organic compounds and good stability in a wide temperature (10 degrees C-90 degrees C) and pH range (3-14). Cane molasses and WFO were the cheap and easily available feedstock which helped economic production of SLs and reduced the production cost. These SLs indicated good potential in further a wide variety of industrial and environmental applications.