Effects of kryptopyrrole on porphyrin synthesis in Bacillus subtilis 168.

We investigated the effects of exogenous 5-aminolaevulinate and kryptopyrrole, separately and together, on the porphyrin synthesis of Bacillus subtilis 168. It was confirmed that 5-aminolaevulinate increases the porphyrin content of the culture fluid in the way previously described. In comparison with the basic activity of the bacteria, kryptopyrrole enhances the amount of extracellular copro III, uro III and 5-carboxyl porphyrins. The combination of 5-aminolaevulinate and kryptopyrrole enhances the porphyrin synthesis; moreover, a more pronounced increased in porphyrin synthesis occurs if the kryptopyrrole solution used is rich in its oxidation products. In this latter case, the amount of 5,6,7-carboxylic porphyrins increases markedly along with uro III and particularly copro III, while suburoporphyrins also makes their appearance. An hypothesis is advanced to explain tentatively the increase in the porphyrin synthesis provoked by kryptopyrrole.