Members of this group, which secrete BoNT types B, E or F, are typically saccharolytic and non-proteolytic. According to 16S rRNA sequencing, they cluster with C. acetobutylicum, C. beijerinckii and C. butyricum.In terms of lipid composition this is the best-studied group of the genus. Like most clostridia and indeed many bacteria, these species contain PE, PG and CL. C. acetobutylicum differs from the other two in having large amounts of glycosyl-diradylglycerols in addition to phospholipids.A distinguishing feature of these species is the presence of significant levels of glycerol-acetals of plasmenylethanolamine (PlaE) and smaller amounts of PG-acetals of PlaE.Glycerol and PG acetals of PlaE were seen by 2D-TLC ( Fig. 3 ) and MS ( Fig. 4 ) in strain Beluga E, and in Eklund 17B and Alaska E (data not shown) ( Table 2 ). Interestingly, strain Beluga E has both PG and plasmenylglycerol (PlaG) acetals of PlaE ( Fig. 4a ). This represents the first identification of PlaG acetals of PlaE.