Melinacidin-Producing Acrostalagmus luteoalbus, a Major Constituent of Mixed Mycobiota Contaminating Insulation Material in an Outdoor Wall

Occupants may complain about indoor air quality in closed spaces where the officially approved standard methods for risk assessment fail to reveal cause of problem. This study describes a rare genus not previously detected Finnish buildings, Acrostalagmus, and its species A. luteoalbus as major constituents mixed microbiota wet cork liner from an outdoor wall. Representatives were also present settled dust offices occupants suffered symptoms related air. One strain, POB8, was identified by ITS sequencing. The strain produced immunosuppressive cytotoxic melinacidins II, III, IV, evidenced mass spectrometry analysis. In addition, classical toxigenic indicating water damage, mycoparasitic Trichoderma, Aspergillus section Versicolores, Circumdati, Nigri, Chaetomium spp., wall problematic rooms. exhibited no visible signs microbial growth, airborne load conidia too low explain reported symptoms. conclusion, we suggest possible migration bioactive metabolites into plausible explanation complaints.