There are relatively few C. botulinum strains in group IV, which is characterized by secretion of the G type toxin. These strains do not ferment sugars and differ from the other groups by lack of lipase production. By 16S rRNA sequence analysis they cluster most closely with C. subterminale and Clostridium estertheticum and also with C. proteolyticus, C. argentinense and C. schirmacherense.The strain G that we examined contained PE, PG and CL with abundant plasmalogen forms ( Table 2 ).