Schoeny et al. determined that PG LOD is 0.003 μmolL -1 (i.e. 3.0 fmolμL -1 ), Huang et al. determined that the LOD of 17:0/14:1-PG 0.80 pmolmL -1 (i.e. 0.8 fmolμL -1 ) and LOQ 2.64 pmolmL -1 (2.64 fmolμL -1 ) using the precursor ion at m/z 153 in negative ion mode. The partial difference between our LOD and the published detection limits may be moderately influenced by the different structures of the detected compounds, i.e., our measured DNPU-PG versus the published LOD of phosphatidylglycerols. For comparing two cultivations, t-test for two independent samples was applied for each combination of ID and temperature separately. T-test was performed in each row separately for R,S; R,R; S,R and S,S isomers.