Shellfish, thiaminase

Enzymes destroying thiamine have been encountered in some species in a number of fresh-water fish, in very few salt-water fish, in some shellfish and Crustacea, in bracken ferns and in three species of intestinal bacteria. They have all received the name of "thiaminase , but it is very probable that we have to do with several, different, enzymes >23 They all bring about a fission of the thiamine molecule, liberating the thiazole part, but only in one case, that of thiaminase of Bacillus aneurinolyticus Kimura el Aoyana, reasonable proof has been obtained of a hydrolytic fission, yielding both moieties of the vitamin molecule z-methyl-q-amino-S-hydroxymethylpyr-imidine and 4-methyl-5(/ -hydroxy)-ethylthiazole. 

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