Resumen de Biosystematics and ecology of hydrocarbon-degrading fungi from air biofilters
Francesc X. Prenafeta-Boldú, Gerritis Sybren de Hoog, Richard C. Summerbell
The identity of a collection of published isolates obtained from biofilters exposed to volatile aromatic hydrocarbons has been re-evaluated by ribosomal DNA sequence analysis. A number of misidentifications were revealed and hydrocarbon-degrading black yeasts commonly belonged to the closely related genera Exophiala and Cladophialophora, both anamorphs of Capronia in the Herpotrichiellaceae family (Chaetothyriales). Relatively little is known on the life cycle of these taxa, but based upon a survey on related strains deposited at the CBS collection (Utrecht, The Netherlands) it was evident that they can generally be characterized as micro-extremophiles. They occupy hostile micro-niches, such as the bark of trees, poisonous materials like oil spills or creosoted wood. These ecological features explain the exceptional biodegradation capacity and tolerance towards the growth-limiting conditions present in air biofilters. Some species in the group exhibit a remarkable pathogenic potential, their mycoses in healthy humans sometimes being fatal. Some of the strains examined appear to be closely related to this second group. Hence, additional studies on the potential biohazard of fungal biofiltration of aromatic hydrocarbons are strongly recommended prior to the full-scale implementation of this technique.
