Enhancing succinic acid productivity in the yeast Yarrowia lipolytica with improved glycerol uptake rate

Development of cost effective and highly efficient process for bio-based succinic acid (SA) production is a main concern for industry. The metabolically engineered Y. lipolytica strain PGC01003 was successfully used for SA production with high titre. However, this strain possesses as main drawback with a low growth rate when glycerol is used as a feedstock. Herein, gene GUT1, encoding glycerol kinase, was over-expressed in strain PGC01003 with the aim to improve glycerol uptake capacity. In the resulting strain RIY420, glycerol uptake was 13.5% higher than for the parental strain. GUT1 gene overexpression also positively influences SA production. In batch bioreactor, SA titre, yield and productivity were 32%, 39% and 143% higher, respectively, than for the parental strain PGC01003. Using a glycerol feeding strategy, SA titre, yield and productivity were further improved by 11%, 5% and 10%, respectively. Moreover, the process duration to yield the highest concentration of SA in the culture supernatant was reduced by 9%. This demonstrated the contribution of metabolically engineered strain RIY420 to lower SA process cost and increase the efficiency of bio-based SA production. (C) 2019 Elsevier B.V. All rights reserved.