Total lipids were extracted from lyophilized bacterial cells after cultivation according to Blight and Dyer. Cultivation temperatures, biomass yields, total extracted lipids, and percentage of PG of total lipids are summarized in Table . Production of biomass, total lipids, and PG follows previously published results for several strains of the genus Bacillus and related genera of the family Bacillaceae . The profile of the lipid class of the bacteria was analyzed using HILIC, where Figure shows standard chromatograms and profiles of two this ion; see Fig. S3 . Fig. shows the shotgun analysis of a mixture of PG homologs from three thermotolerant bacteria isolated in our study. Table shows the relative abundance of the molecular species of these bacteria. Analysis of strains cultured at different temperatures shows that the majority of molecular species of PG were 30: 0-PG, more precisely 15:0/15:0-PG. As an example, the natural and standard negative tandem high-resolution mass spectrum of the major molecular species, i.e., 15:0/15:0-PG spectrum, is shown in Fig. and Table . and Fig. ) . Thus, tandem MS confirmed this structure.