Quantitative analysis of thiaminase activity in certain fish species.

Thiaminase I and II activity of Baltic herring, vendace, smelt and dace was measured. All four fish species were found to contain thiaminase activity. The amounts of thiaminase activity in mug of thiamine split per 100 g of fish tissue per hour at 37 degrees C were: in Baltic herring 115 +/- 60, in dace 11500 +/- 2050, in smelt 25 +/- 25 and in vendace 30+/- 15.