Elucidating the effect of impurities present in different crude glycerol sources on lipid and citric acid production by Yarrowia lipolyticaSKY7

Abstract

AbstractBACKGROUNDCrude glycerol is an industrial by‐product of biodiesel producing companies and requires a high cost for purification. In fact, it is a good carbon source and can be used for lipid production from oleaginous microbes. However, crude glycerol has several impurities that may impact the cellular metabolism for lipid production.RESULTSIn this study, crude glycerol from different sources was employed for lipid production and the effect of its impurities on the biomass and lipid production was investigated on Yarrowia lipolytica SKY7, which is a well‐known yeast for lipid and citric acid production. Growth inhibition was observed in BIOCARDEL, BIOLIQ, and ROTHSAY glycerol when compared with pure glycerol. This was due to high sodium concentrations in BIOCARDEL, high potassium concentrations in BIOLIQ, and high sulphur concentrations in ROTHSAY glycerol. Among three crude glycerol sources, the highest lipid concentration (14.78 g L−1) was obtained using BIOCARDEL glycerol at 96 h. However, the higher citric acid concentrations of 18.70 g L−1 in ROTHSAY glycerol and 12.00 g L−1 in BIOLIQ were obtained at 96 h when compared with 8.30 g L−1 in BIOCARDEL glycerol.CONCLUSIONA high potassium and sulphur concentration in glycerol medium inhibits cell growth and lipid production in Yarrowia lipolytica SKY7, while it favors citric acid production. © 2020 Society of Chemical Industry