Biomass production by novel strains of Yarrowia lipolytica using raw glycerol, derived from biodiesel production

• Conversion of raw glycerol to fodder yeast is an alternative way of its utilization.
• Nutritional value and essential amino acid profile of yeast protein were evaluated.
• Y. lipolytica biomass obtained on glycerol media may be used for nutritional purposes.
• The biomass of Y. lipolytica is an attractive source of unsaturated fatty acids.

This study demonstrated the potential applicability of the isolated strains of Yarrowia lipolytica for the valorization of glycerol waste generated during biodiesel production, throughout biomass production. Twenty-one strains were isolated from different environments and identified as Y. lipolytica. Biomass production from pure glycerol (25 g L−1) was performed in the shake-flasks experiment. Eight strains with the best biomass production ability were chosen for studies in bioreactor (pH 3.5). The analysis of technological process parameters and biomass chemical composition demonstrated that S6 strain was the most suitable for biomass production. Its application allowed obtaining 11.7 and 12.3 g L−1 of the biomass with 1.30 and 1.37 g L−1 h−1 productivity, respectively when pure and raw glycerol (25 g L−1) was used. In the yeast protein amino acid profile the contents of lysine, threonine and phenylalanine/tyrosine were higher than required by FAO/WHO. According to the EAAI, the nutritional value of the biomass reached up to 72.3%.