A tertiary-branched tetra-amine, N4-aminopropylspermidine is a major cellular polyamine in an anaerobic thermophile, Caldisericum exile belonging to a new bacterial phylum, Caldiserica

Acid-extractable cellular polyamines of thermophilic Caldisericum exile belonging to a new bacterial phylum, Caldiserica were analyzed by HPLC and GC. The coexistence of an unusual tertiary brancehed tetra-amine, N4-aminopropylspermidine with spermine, a linear tetra-amine, as the major polyamines in addition to putrescine and spermidine, is first reported in the moderate thermophile isolated from a terrestrial hot spring in Japan. Linear and branched penta-amines were not detected. The novel cellular polyamine profile found in the moderate thermophile has never been observed within various bacteria and archaea previously analyzed.