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The genome of the osmophilic <i>Aspergillus wentii</i>, unlike that of the osmotolerant <i>Aspergillus nidulans</i>, contains only the <i>gfdA</i>, but not the <i>gfdB</i>, glycerol 3-phosphate dehydrogenase gene. Here, we studied transcriptomic changes of <i>A. nidulans</i> (reference strain and Δ<i>gfdB</i> gene deletion mutant) and <i>A. wentii</i> (reference strain and <i>An-gfdB</i> expressing mutant) elicited by high osmolarity. <i>A. nidulans</i> showed a canonic hyperosmotic stress response characterized by the upregulation of the trehalose and glycerol metabolism genes (including <i>gfdB</i>), as well as the genes of the high-osmolarity glycerol (HOG) map kinase pathway. The deletion of <i>gfdB</i> caused only negligible alterations in the transcriptome, suggesting that the glycerol metabolism was flexible enough to compensate for the missing GfdB activity in this species. <i>A. wentii</i> responded differently to increased osmolarity than did <i>A. nidulans</i>, e.g., the bulk upregulation of the glycerol and trehalose metabolism genes, along with the HOG pathway genes, was not detected. The expression of <i>An-gfdB</i> in <i>A. wentii</i> did not abolish osmophily, but it reduced growth and caused much bigger alterations in the transcriptome than did the missing <i>gfdB</i> gene in <i>A. nidulans</i>. Flexible glycerol metabolism and hence, two differently regulated <i>gfd</i> genes, may be more beneficial for osmotolerant (living under changing osmolarity) than for osmophilic (living under constantly high osmolarity) species.