Yeast fermentation, sophorolipids

Sophorolipids are extracellular glycolipids that can be produced in high yields from yeast fermentation. Waller et al (57) carried out metathesis reactions to produce high molecular weight polymers from sophorolipids. Another example of the use of polysaccharide is the paper by Jong (P), where carbohydrates are incorporated in polymer composites. 

In the ciurent stndy the inflnence of aeration rate, inoculum size and fermentation medium volume on the sophorolipids production from the yeast Candida bombicola have been studied. Using the data obtained from a two-level Placket-Biuman ejqjerimental design, linear and cubic models were obtained to understand the interaction amongst the ingredients. The cubic model was used to find the optimal aeration rate, inoculum size and the fermentation medium volume. The maximum production of SLs is predicted to be obtained when the medium volume is 10 mL (in 125 mL Erlemneyer flask), is inoculated with 5% of the inoculum and incubated at 350 rpm... 

Sophorolipids possessing lactone rings are generally more lipophilic than rhanmoUpids and are less sensitive to pH, and often have a lower surface activity per mass than rhamnolipids. They are typically obtained from bacteria or yeasts, particularly from Candida sp. Fermentation is often conducted under nitrogen starvation conditions, with abundant dissolved oxygen being present (Pinzon et al., 2009). Sophorolipids can undergo chemical or enzymatic modification to further tune their surface-active properties (Ashby et al, 2009). 

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