Molecular Characterization and Surfactant Utilization of Scolecobasidium Isolates from Detergent-Rich Indoor Environments

Scolecobasidium, generally found in outdoor samples, were isolated from detergent-rich indoor environments. The isolates from bathrooms and washing machines, because of their exposure to detergents, might be genetically and biologically distinct from outdoor isolates. In this study, 11 Scolecobasidium isolates from detergent-rich indoor environments were examined to find the genetic and biological differences between the indoor and outdoor isolates. One isolate from a wall of a soap factory, showing similar conidia morphology with S. constricta, was phylogenetically distinct from the other Scolecobasidium spp. The 10 isolates from washing machines and bathrooms were identified as S. humicola, but these were classified into 2 groups that differed from the reference strain of S. humicola from leaves. All 11 isolates and the 4 reference strains of S. constricta and S. humicola grew on the medium containing sodium oleate and polyoxyethylene-(9)-lauryl ether, but the reference strains of the other Scolecobasidium spp. grew only on the medium containing sodium oleate. The results showed that S. humicola and S. constricta could utilize both surfactants generally included in soaps or synthetic detergents as nutrients. A further implication is that the genetic variation found in the S. humicola isolates from detergent-rich indoor environments can occur as a result of adaptation to such an environment.