Nitrogen source-driven regulation of Irpex lacteus for enhanced lignocellulose degradation and microbial protein production in wheat straw

White rot fungi, such as Irpex lacteus, offer significant potential for lignocellulose degradation and protein synthesis in sustainable biofuel and animal feed production,but optimizing nitrogen sources to balance fungal growth, lignin degradation, and protein synthesis remains a critical challenge.This study investigated the effects of ammonium chloride (NH4Cl) and sodium nitrate (NaNO3) on I. lacteus fermentation in wheat straw, with a focus on the regulation of nitrogen source.Transcriptomic analysis revealed that NaNO3 upregulated genes associated with nitrogen uptake and cellulose/hemicellulose degradation,while exerting less repression on key ligninolytic enzymes, such as manganese peroxidase and cytochrome P450, compared to NH4Cl.These findings suggest that NaNO3 enhances I. lacteus metabolism by harmonizing lignin degradation with efficient nitrogen conversion. Overall design: To investigate the effects of different nitrogen sources on the fermentation of wheat straw by the fungus Tricholoma album, a study was conducted where ammonium chloride and sodium nitrate solutions were added as inorganic nitrogen sources. A control group was also set up by adding distilled water. Subsequently, transcriptional sequencing was performed on the fermentation samples.