Use of Immunoassays for the Study of Natural Assemblages of Aquatic Hyphomycetes

Specific monoclonal antibodies raised in previous studies were used in a quantitative ELISA to determine the biomass of three species of aquatic hyphomycetes: Tetracladium marchalianum de Wild, Anguillospora longissima Ingold, and Alatospora acuminata Ingold. The use of these methods for the study of mixed assemblages was assessed in the laboratory. The presence of nontarget fungi did not interfere with specific recognition by antibodies in the ELISA assay. The immunoassays indicated that lower biomass was attained by individual species colonizing field-incubated leaf material compared to laboratory-inoculated material. Alatospora acuminata attained the highest relative biomass on field-incubated leaf material, and T. marchalianum the lowest. These results contrast sharply with those obtained using more conventional methods based on conidial abundance. Conidia of T. marchaliamum were recorded more frequently than conidia of A. acuminata, and are, therefore, assumed to have had a higher relative abundance. The implications of these apparently conflicting results are discussed.