Production of organically bound halogens by the litter-degrading fungus Lepista nuda

The ability of Lepista nuda to produce organically bound halogens was tested both in a laboratory study of a pure culture and in a field study. It was found that L. nuda caused an increase in the total amount of organically bound halogens in the study of a pure culture, but possibly because of large variance between replicates, no such increase could be detected in the field study. In addition, in both the laboratory and the field studies, low-molecular-weight organohalogens such as chlorinated benzaldehydes were detected in all samples affected by the fungus and the amounts were 0.2–82 μg/g d.w. These low-molecular-weight compounds correspond to approximately 30% of the increase in organohalogens detected in the laboratory study. It is suggested that the low-molecular-weight organohalogens detected, most likely are produced de novo by L. nuda and that production of such compounds followed by an incorporation into high-molecular-weight compounds is an explanation for the increase in amounts in the laboratory study.