Paradendryphiella salina Genome sequencing. Paradendryphiella salina

Hydrophobins (HFBs) and cerato-platanins (CPs) are hydrophobic and surface-active extracellular proteins produced by filamentous fungi. We here identified two HFB genes (pshyd1 and pshyd2) and one CP gene (pscp) within the genome sequence of the marine fungus Paradendryphiella salina. PsCP, PsHYD2 and PsHYD1 had a molecular weight of 12.70, 6.62, and 5.98 kDa, respectively, with an isoelectric point below 7. PsHYD 1 and PsHYD 2 exhibited identical positive GRAVY scores (0.462), indicating hydrophobicity, whereas PsCP showed a negative GRAVY score (-0.202), suggesting hydrophilicity. Stability indices for all proteins were below 40, suggesting in-solution stability. Mass spectrometry identified 2,922 proteins, including the CP but not the HFBs, when P. salina had been grown on different carbon sources (sucrose, alginate, seaweed). qPCR analysis under various growth conditions revealed differential gene expression influenced by developmental stages and the substrates tested. Notably, pshyd1 was consistently expressed across all developmental stages studied. Our findings suggest the potential of P. salina to evolutionary adaptation to marine ecosystems, possibly featuring fewer hydrophobin genes than its halophilic and terrestrial counterparts, yet highlighting its capacity to produce surface-active proteins when utilizing seaweed carbohydrates. These proteins hold biotechnological promise, with applications extending from medical bio-coatings for various materials to food industry uses, such as foam stabilizers, and environmental applications in bioremediation.