THE RODLET LAYER FROM AERIAL AND SUBMERGED CONIDIA OF THE ENTOMOPATHOGENIC FUNGUS BEAUVERIA-BASSIANA CONTAINS HYDROPHOBIN

The entomopathogenic fungus Beauveria bassiana produces aerial conidia , submerged conidia or blastospores depending on the culture condition s. Rodlets are observed on aerial and submerged conidia but not on bla stospores. Cell wall rodlets were removed by sonication and the protei ns dissolved with formic acid. A single major 9 . 7 kDa protein was fo und in rodlets of aerial and submerged conidia and showed N terminal s equence similarities to the hydrophobin class of fungal proteins. Hydr ophobin could not be recovered from blastospores. Oxidation of the hyd rophobin with performic acid produced a protein of higher molecular we ight (14 . 0 kDa). The rodlet layer could not be removed from intact c onidia by boiling in sodium dodecyl sulphate (SDS) but could be remove d with formic add. Formic acid treated conidia retained the ability to bind to insect cuticles and retained hydrophobicity as indicated by a phase exclusion assay.