## 2 Glycerol-Based Biomanufacturing Using _Yarrowia_
### Bioconversion of Glycerol to Lipids
#### 2.1.2 Pure and Crude Glycerol as Carbon Source for Lipid Production by _Yarrowia lipolytica_
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Strain**} & **Carbon Source 1** & \multirow{2}{*}{**Product**} & **Engineering 2** & \multirow{2}{*}{**Strategy**} & **Set-Up 3** & **Data from [Ref.]** \\ \hline \multirow{3}{*}{A101} & \multirow{3}{*}{CG} & \multirow{3}{*}{25\% \(w/w\) lipids} & \multirow{3}{*}{ME} & Waste products containing & \multirow{3}{*}{SF} & \multirow{3}{*}{[54]} \\  & & & various glycerol & & & \\  & & concentrations of (42–87\%); & & & & \\  & & & pH 6.0 & & & \\ \hline \multirow{3}{*}{SKY7} & \multirow{3}{*}{CG} & \multirow{3}{*}{45.5\% \(w/w\) lipids} & \multirow{3}{*}{ME} & Glycerol-supplemented & \multirow{3}{*}{B} & \multirow{3}{*}{[55]} \\  & & & media with pH 6.5 and & & & \\  & & & without pH control & & & \\ \hline \multirow{3}{*}{SKY7} & \multirow{3}{*}{CG} & \multirow{3}{*}{29.35\% \(w/w\) lipids} & \multirow{3}{*}{ME} & Sludge media with different & \multirow{3}{*}{SF} & \multirow{3}{*}{[56]} \\  & & & lipids & ph 6.8 & & \\ \hline \multirow{3}{*}{DiSVA 347} & \multirow{3}{*}{CG} & \multirow{3}{*}{25.7\% \(w/w\) lipids} & \multirow{3}{*}{SS; ME} & Glycerol concentration; C/N & \multirow{3}{*}{SF} & \multirow{3}{*}{[57]} \\  & & & ratio and time process; & & & \\  & & & pH 6.0 & & & \\ \hline \multirow{3}{*}{JMY4086} & \multirow{3}{*}{CG} & \multirow{3}{*}{40\% \(w/w\) lipids} & \multirow{3}{*}{SE; PE} & Deletion of _POX1–6_ and & \multirow{3}{*}{B} & \multirow{3}{*}{[58]} \\  & & & _TGL4_ gene, overexpression & & & \\  & & & & of _YIDGA2, YIGPD1, SUC2,_ & & & \\  & & & _HXXI_; oxygenation; & & & \\  & & & & inoculum densities; pH 3.5 & & \\ \hline \multirow{3}{*}{A101} & \multirow{3}{*}{CG} & \multirow{3}{*}{21\% \(w/w\) lipids} & \multirow{3}{*}{SE; ME} & _DGA1_ overexpression; & \multirow{3}{*}{B} & \multirow{3}{*}{[59]} \\  & & & seawater; pH 3.0 & & & \\ \hline \multirow{3}{*}{NCYC3825} & \multirow{3}{*}{PG} & \multirow{3}{*}{38\% \(w/w\) lipids} & \multirow{3}{*}{SE} & Genetic construct with & \multirow{3}{*}{B} & \multirow{3}{*}{[9]} \\  & & & & 3 heterologous genes & & \\  & & & (glycerol dehydatase and its & & \\  & & & & reactivity, wide-spectrum & & \\  & & & alcohol oxidoreductase) & & \\  & & & under the control of & & & \\  & & & & glycerol-induced promoter; & & \\  & & & & pH 4.0 & & \\ \hline \multirow{3}{*}{Polh} & \multirow{3}{*}{PG} & \multirow{3}{*}{23\% \(w/w\) lipids} & \multirow{3}{*}{SE} & \multirow{3}{*}{Overexpression of \(\,\)ATP:citrate lyase from _Mus musculus_ with the multi-copy integration vector plNA1292 sp; pH 6.0} & \multirow{3}{*}{[60]} \\  & & & & One-step double gene & \multirow{3}{*}{B} & \multirow{3}{*}{[61]} \\  & & & & knock-in and site-specific & & \\  & & & gene knock-out; _DGA1_ and & & \\  & & & _DGA2_ in a _POX-_deleted background; deletion of the & & \\  & & & & _SNF1_ lipid regulator; & & \\  & & & pH \(\geq\) 2.5 & & & \\ \hline \multirow{3}{*}{JMY3580} & \multirow{3}{*}{PG} & \multirow{3}{*}{53.7\% \(w/w\) lipids} & \multirow{3}{*}{SE} & _DGA2_ gene in Q4 strain (_Agg1_\(\Delta\)_dga2_\(\Delta\)_tr0_\(\Delta\)_A_are_1_); pH not regulated & \multirow{3}{*}{SF} & \multirow{3}{*}{[52]} \\  & & & & & & \\ \hline \multirow{3}{*}{MUCL} & \multirow{3}{*}{PG} & \multirow{3}{*}{38.1\% \(w/w\) lipids} & \multirow{3}{*}{ME; PE} & Addition of volatile fatty & \multirow{3}{*}{B} & \multirow{3}{*}{[62]} \\  & & & lipids & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._growth rate and lipid yield [41; 50]. For instance, to study the kinetics of lipid production in _Y. lipolytica_ strain IMUFRJ 50682, [PERSON] et al., tested media with varying amounts of pure glycerol as carbon source and a fixed amount of ammonium sulfate (3 g L\({}^{-1}\)) as nitrogen source. With an increase of the C/N ratio, lipid accumulation increased to 4 g L\({}^{-1}\), followed by substrate inhibition. The best lipid formation rate and titer were obtained with an initial glycerol concentration of 93 g L\({}^{-1}\). While lipid production was high, citric acid production in the medium was negligible.