Filamentous fungal host cells expressing hypoxia responsive morphology factor A (hrmA) and biofilm architecture factor (baf) proteins are provided. Methods of producing filamentous fungal host cells expressing hrmA and baf proteins are also provided. In one aspect, the disclosure provides a filamentous fungal host cell, comprising a nucleotide sequence encoding an Aspergillus fumigatus hypoxia responsive morphology factor A (hrmA) protein, or a homolog or ortholog thereof.