*4.5. Quantification of Glucose, Glycerol, Acetate, and Ammonia*

The quantifications of glucose, glycerol, and acetate concentrations were performed by high performance liquid chromatography (HPLC) with a LaChrome Elite HPLC system (VWR, Darmstadt, Germany), equipped with a Trentec 308R-Gel.H column (Trentec Analysetechnik, Gerlingen, Germany) and a refractive index detector. The mobile phase consisted of 5 mM sulphuric acid. An isocratic method was used, with a flow rate of 1 mL min−<sup>1</sup> and an injection volume of 20 μL. The column oven was set to 40 ◦C. Eluted components were quantified using standard curves for glucose, glycerol, and acetate.

Ammonia concentrations were determined by the method of Berthelot [39].

**Author Contributions:** Conceptualization, M.K.J. and S.L.; methodology, J.R. and M.K.J.; formal analysis, J.R.; investigation, J.R.; resources, S.L.; data curation, K.R., M.K.J. and S.L.; writing—original draft preparation, J.R. and K.R.; writing—review and editing, K.R., M.K.J. and S.L.; visualization, J.R.; supervision, M.K.J. and S.L.; project administration, M.K.J. and S.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** We acknowledge financial support by Deutsche Forschungsgemeinschaft and TU Dortmund University within the funding program Open Access Publishing. We gratefully thank Christian Willrodt for fruitful scientific discussions and Saikai Humaerhan for her support in initial growth studies.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

#### **Appendix A**

**Figure A1.** Two-liquid phase shake flask fermentations with *E. coli* BL21 (DE3) pJBEI-6410 in M9 minimal medium with either 0.5% *w*/*v* glucose (closed symbols, •) or glycerol (open symbols, -) as the sole carbon source. Cell dry weights were determined at regular intervals. The error bars relate to biological duplicates.

#### **References**


**Sample Availability:** Samples of the compound (S)-limonene in DINP are available from the authors.

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