Hydrolysis of iodothyronine sulfates by sulfatase activity of anaerobic bacteria from the rat intestinal flora

2 Obligately anaerobic bacteria isolated from rat cecal flora have previously been shown to possess sulfatase activity towards 3,3′-diiodothyronine sulfate [5]. These strains have now been tested for their ability to hydrolyze the sulfate conjugates of other iodothyronines, including the thyroid hormones thyroxine and 3,3′,5-triiodothyronine. In anaerobic incubations at 37°C with approximately 107 bacteria per ml, variable amounts of the conjugated substrates, ranging from 15–90%, were hydrolysed in 24 h. These results showed a potent iodothyronine sulfate hydrolysing capacity of rat intestinal microflora. The strains were characterized by carbohydrate fermentation tests. One strain belonged to the genus Lactobacillus, the other strain probably to Eubacterium or Lachnospira.