Figure 1

Distribution of glutathione mapped onto a universal tree of life based on 16S rRNA sequences. Information was obtained from an extensive search of the literature on the occurrence of glutathione in various organisms and was supplemented by data obtained from the sequence database. Green dots indicate that glutathione is present in the indicated organisms, whereas red dots indicate that glutathione is absent. The light green dot indicates that glutathione is found in some strains of some low-GC Gram-positive bacteria (Streptococcus, Enterococcus, Clostridium and Listeria) but not in others (Staphylococcus) [4]. Some strains of Gram-positive bacteria (for example, Streptococcus thermophilus, Streptococcus agalactiae and Enterococcus faecalis [4]) appear to synthesize GSH, whereas others (Streptococcus mutans [58]) just import it from the medium. In others (Clostridium and Listeria), this question has not been resolved [4].