From sewage scum up to lipids production using oleaginous yeasts as biocatalysts

For the first time, the fermentation of undetoxified sugar-rich sewage scum hydrolysate, a special waste separated during municipal wastewater treatment, was successfully achieved using a promising commercial yeast to produce microbial oil. One of the most critical factors affecting its cost production is the feedstock; therefore, using low-cost or even negative-value waste resources, such as sewage scum, could significantly reduce its manufacturing price and, consequently, that of the obtained biodiesel and fine oleochemicals. Moreover, the valorization of the sewage scum would lower the disposal expenses of this waste, also reducing its environmental concerns, in agreement with Green Chemistry principles.